[2/5] drivers: mtd: nand: Add qpic_common API file

Add qpic_common.c file which hold all the common
qpic APIs which will be used by both qpic raw nand
driver and qpic spi nand driver.

Co-developed-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
Signed-off-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
Co-developed-by: Varadarajan Narayanan <quic_varada@quicinc.com>
Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
---
 drivers/mtd/nand/Makefile            |    1 +
 drivers/mtd/nand/qpic_common.c       |  786 +++++++++++++++++
 drivers/mtd/nand/raw/qcom_nandc.c    | 1226 +-------------------------
 include/linux/mtd/nand-qpic-common.h |  488 ++++++++++
 4 files changed, 1291 insertions(+), 1210 deletions(-)
 create mode 100644 drivers/mtd/nand/qpic_common.c
 create mode 100644 include/linux/mtd/nand-qpic-common.h

On 2/15/2024 7:18 PM, Md Sadre Alam wrote:
> Add qpic_common.c file which hold all the common
> qpic APIs which will be used by both qpic raw nand
> driver and qpic spi nand driver.
> 
> Co-developed-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
> Signed-off-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
> Co-developed-by: Varadarajan Narayanan <quic_varada@quicinc.com>
> Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
> Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
> ---
>   drivers/mtd/nand/Makefile            |    1 +
>   drivers/mtd/nand/qpic_common.c       |  786 +++++++++++++++++
>   drivers/mtd/nand/raw/qcom_nandc.c    | 1226 +-------------------------
>   include/linux/mtd/nand-qpic-common.h |  488 ++++++++++
>   4 files changed, 1291 insertions(+), 1210 deletions(-)
>   create mode 100644 drivers/mtd/nand/qpic_common.c
>   create mode 100644 include/linux/mtd/nand-qpic-common.h
> 
> diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
> index 19e1291ac4d5..131707a41293 100644
> --- a/drivers/mtd/nand/Makefile
> +++ b/drivers/mtd/nand/Makefile
> @@ -12,3 +12,4 @@ nandcore-$(CONFIG_MTD_NAND_ECC) += ecc.o
>   nandcore-$(CONFIG_MTD_NAND_ECC_SW_HAMMING) += ecc-sw-hamming.o
>   nandcore-$(CONFIG_MTD_NAND_ECC_SW_BCH) += ecc-sw-bch.o
>   nandcore-$(CONFIG_MTD_NAND_ECC_MXIC) += ecc-mxic.o
> +obj-y += qpic_common.o
> diff --git a/drivers/mtd/nand/qpic_common.c b/drivers/mtd/nand/qpic_common.c
> new file mode 100644
> index 000000000000..4d74ba888028
> --- /dev/null
> +++ b/drivers/mtd/nand/qpic_common.c
> @@ -0,0 +1,786 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * QPIC Controller common API file.
> + * Copyright (C) 2023  Qualcomm Inc.


Copyright should be repharsed?


> + * Authors:	Md sadre Alam           <quic_mdalam@quicinc.com>
> + *		Sricharan R             <quic_srichara@quicinc.com>
> + *		Varadarajan Narayanan	<quic_varada@quicinc.com>
> + *
> + */
> +
> +#include <linux/mtd/nand-qpic-common.h>
> +
> +struct qcom_nand_controller *
> +get_qcom_nand_controller(struct nand_chip *chip)
> +{
> +	return container_of(chip->controller, struct qcom_nand_controller,
> +			    controller);
> +}
> +EXPORT_SYMBOL(get_qcom_nand_controller);
> +
> +/*
> + * Helper to prepare DMA descriptors for configuring registers
> + * before reading a NAND page.
> + */
> +void config_nand_page_read(struct nand_chip *chip)
> +{
> +	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
> +
> +	write_reg_dma(nandc, NAND_ADDR0, 2, 0);
> +	write_reg_dma(nandc, NAND_DEV0_CFG0, 3, 0);
> +	if (!nandc->props->qpic_v2)
> +		write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1, 0);
> +	write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1, 0);
> +	write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1,
> +		      NAND_ERASED_CW_SET | NAND_BAM_NEXT_SGL);
> +}
> +EXPORT_SYMBOL(config_nand_page_read);
> +
> +/* Frees the BAM transaction memory */
> +void free_bam_transaction(struct qcom_nand_controller *nandc)
> +{
> +	struct bam_transaction *bam_txn = nandc->bam_txn;
> +
> +	devm_kfree(nandc->dev, bam_txn);
> +}
> +EXPORT_SYMBOL(free_bam_transaction);
> +
> +/* Callback for DMA descriptor completion */
> +void qpic_bam_dma_done(void *data)
> +{
> +	struct bam_transaction *bam_txn = data;
> +
> +	/*
> +	 * In case of data transfer with NAND, 2 callbacks will be generated.
> +	 * One for command channel and another one for data channel.
> +	 * If current transaction has data descriptors
> +	 * (i.e. wait_second_completion is true), then set this to false
> +	 * and wait for second DMA descriptor completion.
> +	 */
> +	if (bam_txn->wait_second_completion)
> +		bam_txn->wait_second_completion = false;
> +	else
> +		complete(&bam_txn->txn_done);
> +}
> +EXPORT_SYMBOL(qpic_bam_dma_done);
> +
> +void nandc_read_buffer_sync(struct qcom_nand_controller *nandc,
> +			    bool is_cpu)
> +{
> +	if (!nandc->props->is_bam)
> +		return;
> +
> +	if (is_cpu)
> +		dma_sync_single_for_cpu(nandc->dev, nandc->reg_read_dma,
> +					MAX_REG_RD *
> +					sizeof(*nandc->reg_read_buf),
> +					DMA_FROM_DEVICE);
> +	else
> +		dma_sync_single_for_device(nandc->dev, nandc->reg_read_dma,
> +					   MAX_REG_RD *
> +					   sizeof(*nandc->reg_read_buf),
> +					   DMA_FROM_DEVICE);
> +}
> +EXPORT_SYMBOL(nandc_read_buffer_sync);
> +
> +__le32 *offset_to_nandc_reg(struct nandc_regs *regs, int offset)
> +{
> +	switch (offset) {
> +	case NAND_FLASH_CMD:
> +		return &regs->cmd;
> +	case NAND_ADDR0:
> +		return &regs->addr0;
> +	case NAND_ADDR1:
> +		return &regs->addr1;
> +	case NAND_FLASH_CHIP_SELECT:
> +		return &regs->chip_sel;
> +	case NAND_EXEC_CMD:
> +		return &regs->exec;
> +	case NAND_FLASH_STATUS:
> +		return &regs->clrflashstatus;
> +	case NAND_DEV0_CFG0:
> +		return &regs->cfg0;
> +	case NAND_DEV0_CFG1:
> +		return &regs->cfg1;
> +	case NAND_DEV0_ECC_CFG:
> +		return &regs->ecc_bch_cfg;
> +	case NAND_READ_STATUS:
> +		return &regs->clrreadstatus;
> +	case NAND_DEV_CMD1:
> +		return &regs->cmd1;
> +	case NAND_DEV_CMD1_RESTORE:
> +		return &regs->orig_cmd1;
> +	case NAND_DEV_CMD_VLD:
> +		return &regs->vld;
> +	case NAND_DEV_CMD_VLD_RESTORE:
> +		return &regs->orig_vld;
> +	case NAND_EBI2_ECC_BUF_CFG:
> +		return &regs->ecc_buf_cfg;
> +	case NAND_READ_LOCATION_0:
> +		return &regs->read_location0;
> +	case NAND_READ_LOCATION_1:
> +		return &regs->read_location1;
> +	case NAND_READ_LOCATION_2:
> +		return &regs->read_location2;
> +	case NAND_READ_LOCATION_3:
> +		return &regs->read_location3;
> +	case NAND_READ_LOCATION_LAST_CW_0:
> +		return &regs->read_location_last0;
> +	case NAND_READ_LOCATION_LAST_CW_1:
> +		return &regs->read_location_last1;
> +	case NAND_READ_LOCATION_LAST_CW_2:
> +		return &regs->read_location_last2;
> +	case NAND_READ_LOCATION_LAST_CW_3:
> +		return &regs->read_location_last3;
> +	default:
> +		return NULL;
> +	}
> +}
> +EXPORT_SYMBOL(offset_to_nandc_reg);
> +
> +/* reset the register read buffer for next NAND operation */
> +void clear_read_regs(struct qcom_nand_controller *nandc)
> +{
> +	nandc->reg_read_pos = 0;
> +	nandc_read_buffer_sync(nandc, false);
> +}
> +EXPORT_SYMBOL(clear_read_regs);
> +
> +int prep_adm_dma_desc(struct qcom_nand_controller *nandc, bool read,
> +		      int reg_off, const void *vaddr, int size,
> +			     bool flow_control)
> +{
> +	struct desc_info *desc;
> +	struct dma_async_tx_descriptor *dma_desc;
> +	struct scatterlist *sgl;
> +	struct dma_slave_config slave_conf;
> +	struct qcom_adm_peripheral_config periph_conf = {};
> +	enum dma_transfer_direction dir_eng;
> +	int ret;
> +
> +	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
> +	if (!desc)
> +		return -ENOMEM;
> +
> +	sgl = &desc->adm_sgl;
> +
> +	sg_init_one(sgl, vaddr, size);
> +
> +	if (read) {
> +		dir_eng = DMA_DEV_TO_MEM;
> +		desc->dir = DMA_FROM_DEVICE;
> +	} else {
> +		dir_eng = DMA_MEM_TO_DEV;
> +		desc->dir = DMA_TO_DEVICE;
> +	}
> +
> +	ret = dma_map_sg(nandc->dev, sgl, 1, desc->dir);
> +	if (ret == 0) {
> +		ret = -ENOMEM;
> +		goto err;
> +	}
> +
> +	memset(&slave_conf, 0x00, sizeof(slave_conf));
> +
> +	slave_conf.device_fc = flow_control;
> +	if (read) {
> +		slave_conf.src_maxburst = 16;
> +		slave_conf.src_addr = nandc->base_dma + reg_off;
> +		if (nandc->data_crci) {
> +			periph_conf.crci = nandc->data_crci;
> +			slave_conf.peripheral_config = &periph_conf;
> +			slave_conf.peripheral_size = sizeof(periph_conf);
> +		}
> +	} else {
> +		slave_conf.dst_maxburst = 16;
> +		slave_conf.dst_addr = nandc->base_dma + reg_off;
> +		if (nandc->cmd_crci) {
> +			periph_conf.crci = nandc->cmd_crci;
> +			slave_conf.peripheral_config = &periph_conf;
> +			slave_conf.peripheral_size = sizeof(periph_conf);
> +		}
> +	}
> +
> +	ret = dmaengine_slave_config(nandc->chan, &slave_conf);
> +	if (ret) {
> +		dev_err(nandc->dev, "failed to configure dma channel\n");
> +		goto err;
> +	}
> +
> +	dma_desc = dmaengine_prep_slave_sg(nandc->chan, sgl, 1, dir_eng, 0);
> +	if (!dma_desc) {
> +		dev_err(nandc->dev, "failed to prepare desc\n");
> +		ret = -EINVAL;
> +		goto err;
> +	}
> +
> +	desc->dma_desc = dma_desc;
> +
> +	list_add_tail(&desc->node, &nandc->desc_list);
> +
> +	return 0;
> +err:
> +	kfree(desc);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL(prep_adm_dma_desc);
> +
> +/* helpers to submit/free our list of dma descriptors */
> +int submit_descs(struct qcom_nand_controller *nandc)
> +{
> +	struct desc_info *desc, *n;
> +	dma_cookie_t cookie = 0;
> +	struct bam_transaction *bam_txn = nandc->bam_txn;
> +	int ret = 0;
> +
> +	if (nandc->props->is_bam) {
> +		if (bam_txn->rx_sgl_pos > bam_txn->rx_sgl_start) {
> +			ret = prepare_bam_async_desc(nandc, nandc->rx_chan, 0);
> +			if (ret)
> +				goto err_unmap_free_desc;
> +		}
> +
> +		if (bam_txn->tx_sgl_pos > bam_txn->tx_sgl_start) {
> +			ret = prepare_bam_async_desc(nandc, nandc->tx_chan,
> +						     DMA_PREP_INTERRUPT);
> +			if (ret)
> +				goto err_unmap_free_desc;
> +		}
> +
> +		if (bam_txn->cmd_sgl_pos > bam_txn->cmd_sgl_start) {
> +			ret = prepare_bam_async_desc(nandc, nandc->cmd_chan,
> +						     DMA_PREP_CMD);
> +			if (ret)
> +				goto err_unmap_free_desc;
> +		}
> +	}
> +
> +	list_for_each_entry(desc, &nandc->desc_list, node)
> +		cookie = dmaengine_submit(desc->dma_desc);
> +
> +	if (nandc->props->is_bam) {
> +		bam_txn->last_cmd_desc->callback = qpic_bam_dma_done;
> +		bam_txn->last_cmd_desc->callback_param = bam_txn;
> +		if (bam_txn->last_data_desc) {
> +			bam_txn->last_data_desc->callback = qpic_bam_dma_done;
> +			bam_txn->last_data_desc->callback_param = bam_txn;
> +			bam_txn->wait_second_completion = true;
> +		}
> +
> +		dma_async_issue_pending(nandc->tx_chan);
> +		dma_async_issue_pending(nandc->rx_chan);
> +		dma_async_issue_pending(nandc->cmd_chan);
> +
> +		if (!wait_for_completion_timeout(&bam_txn->txn_done,
> +						 QPIC_NAND_COMPLETION_TIMEOUT))
> +			ret = -ETIMEDOUT;
> +	} else {
> +		if (dma_sync_wait(nandc->chan, cookie) != DMA_COMPLETE)
> +			ret = -ETIMEDOUT;
> +	}
> +
> +err_unmap_free_desc:
> +	/*
> +	 * Unmap the dma sg_list and free the desc allocated by both
> +	 * prepare_bam_async_desc() and prep_adm_dma_desc() functions.
> +	 */
> +	list_for_each_entry_safe(desc, n, &nandc->desc_list, node) {
> +		list_del(&desc->node);
> +
> +		if (nandc->props->is_bam)
> +			dma_unmap_sg(nandc->dev, desc->bam_sgl,
> +				     desc->sgl_cnt, desc->dir);
> +		else
> +			dma_unmap_sg(nandc->dev, &desc->adm_sgl, 1,
> +				     desc->dir);
> +
> +		kfree(desc);
> +	}
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL(submit_descs);
> +
> +/*
> + * Maps the scatter gather list for DMA transfer and forms the DMA descriptor
> + * for BAM. This descriptor will be added in the NAND DMA descriptor queue
> + * which will be submitted to DMA engine.
> + */
> +int prepare_bam_async_desc(struct qcom_nand_controller *nandc,
> +			   struct dma_chan *chan,
> +				  unsigned long flags)
> +{
> +	struct desc_info *desc;
> +	struct scatterlist *sgl;
> +	unsigned int sgl_cnt;
> +	int ret;
> +	struct bam_transaction *bam_txn = nandc->bam_txn;
> +	enum dma_transfer_direction dir_eng;
> +	struct dma_async_tx_descriptor *dma_desc;
> +
> +	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
> +	if (!desc)
> +		return -ENOMEM;
> +
> +	if (chan == nandc->cmd_chan) {
> +		sgl = &bam_txn->cmd_sgl[bam_txn->cmd_sgl_start];
> +		sgl_cnt = bam_txn->cmd_sgl_pos - bam_txn->cmd_sgl_start;
> +		bam_txn->cmd_sgl_start = bam_txn->cmd_sgl_pos;
> +		dir_eng = DMA_MEM_TO_DEV;
> +		desc->dir = DMA_TO_DEVICE;
> +	} else if (chan == nandc->tx_chan) {
> +		sgl = &bam_txn->data_sgl[bam_txn->tx_sgl_start];
> +		sgl_cnt = bam_txn->tx_sgl_pos - bam_txn->tx_sgl_start;
> +		bam_txn->tx_sgl_start = bam_txn->tx_sgl_pos;
> +		dir_eng = DMA_MEM_TO_DEV;
> +		desc->dir = DMA_TO_DEVICE;
> +	} else {
> +		sgl = &bam_txn->data_sgl[bam_txn->rx_sgl_start];
> +		sgl_cnt = bam_txn->rx_sgl_pos - bam_txn->rx_sgl_start;
> +		bam_txn->rx_sgl_start = bam_txn->rx_sgl_pos;
> +		dir_eng = DMA_DEV_TO_MEM;
> +		desc->dir = DMA_FROM_DEVICE;
> +	}
> +
> +	sg_mark_end(sgl + sgl_cnt - 1);
> +	ret = dma_map_sg(nandc->dev, sgl, sgl_cnt, desc->dir);
> +	if (ret == 0) {
> +		dev_err(nandc->dev, "failure in mapping desc\n");
> +		kfree(desc);
> +		return -ENOMEM;
> +	}
> +
> +	desc->sgl_cnt = sgl_cnt;
> +	desc->bam_sgl = sgl;
> +
> +	dma_desc = dmaengine_prep_slave_sg(chan, sgl, sgl_cnt, dir_eng,
> +					   flags);
> +
> +	if (!dma_desc) {
> +		dev_err(nandc->dev, "failure in prep desc\n");
> +		dma_unmap_sg(nandc->dev, sgl, sgl_cnt, desc->dir);
> +		kfree(desc);
> +		return -EINVAL;
> +	}
> +
> +	desc->dma_desc = dma_desc;
> +
> +	/* update last data/command descriptor */
> +	if (chan == nandc->cmd_chan)
> +		bam_txn->last_cmd_desc = dma_desc;
> +	else
> +		bam_txn->last_data_desc = dma_desc;
> +
> +	list_add_tail(&desc->node, &nandc->desc_list);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(prepare_bam_async_desc);
> +
> +/*
> + * Prepares the command descriptor for BAM DMA which will be used for NAND
> + * register reads and writes. The command descriptor requires the command
> + * to be formed in command element type so this function uses the command
> + * element from bam transaction ce array and fills the same with required
> + * data. A single SGL can contain multiple command elements so
> + * NAND_BAM_NEXT_SGL will be used for starting the separate SGL
> + * after the current command element.
> + */
> +int prep_bam_dma_desc_cmd(struct qcom_nand_controller *nandc, bool read,
> +			  int reg_off, const void *vaddr,
> +				 int size, unsigned int flags)
> +{
> +	int bam_ce_size;
> +	int i, ret;
> +	struct bam_cmd_element *bam_ce_buffer;
> +	struct bam_transaction *bam_txn = nandc->bam_txn;
> +
> +	bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_pos];
> +
> +	/* fill the command desc */
> +	for (i = 0; i < size; i++) {
> +		if (read)
> +			bam_prep_ce(&bam_ce_buffer[i],
> +				    nandc_reg_phys(nandc, reg_off + 4 * i),
> +				    BAM_READ_COMMAND,
> +				    reg_buf_dma_addr(nandc,
> +						     (__le32 *)vaddr + i));
> +		else
> +			bam_prep_ce_le32(&bam_ce_buffer[i],
> +					 nandc_reg_phys(nandc, reg_off + 4 * i),
> +					 BAM_WRITE_COMMAND,
> +					 *((__le32 *)vaddr + i));
> +	}
> +
> +	bam_txn->bam_ce_pos += size;
> +
> +	/* use the separate sgl after this command */
> +	if (flags & NAND_BAM_NEXT_SGL) {
> +		bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_start];
> +		bam_ce_size = (bam_txn->bam_ce_pos -
> +				bam_txn->bam_ce_start) *
> +				sizeof(struct bam_cmd_element);
> +		sg_set_buf(&bam_txn->cmd_sgl[bam_txn->cmd_sgl_pos],
> +			   bam_ce_buffer, bam_ce_size);
> +		bam_txn->cmd_sgl_pos++;
> +		bam_txn->bam_ce_start = bam_txn->bam_ce_pos;
> +
> +		if (flags & NAND_BAM_NWD) {
> +			ret = prepare_bam_async_desc(nandc, nandc->cmd_chan,
> +						     DMA_PREP_FENCE |
> +						     DMA_PREP_CMD);
> +			if (ret)
> +				return ret;
> +		}
> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(prep_bam_dma_desc_cmd);
> +
> +/*
> + * Prepares the data descriptor for BAM DMA which will be used for NAND
> + * data reads and writes.
> + */
> +int prep_bam_dma_desc_data(struct qcom_nand_controller *nandc, bool read,
> +			   const void *vaddr,
> +				  int size, unsigned int flags)
> +{
> +	int ret;
> +	struct bam_transaction *bam_txn = nandc->bam_txn;
> +
> +	if (read) {
> +		sg_set_buf(&bam_txn->data_sgl[bam_txn->rx_sgl_pos],
> +			   vaddr, size);
> +		bam_txn->rx_sgl_pos++;
> +	} else {
> +		sg_set_buf(&bam_txn->data_sgl[bam_txn->tx_sgl_pos],
> +			   vaddr, size);
> +		bam_txn->tx_sgl_pos++;
> +
> +		/*
> +		 * BAM will only set EOT for DMA_PREP_INTERRUPT so if this flag
> +		 * is not set, form the DMA descriptor
> +		 */
> +		if (!(flags & NAND_BAM_NO_EOT)) {
> +			ret = prepare_bam_async_desc(nandc, nandc->tx_chan,
> +						     DMA_PREP_INTERRUPT);
> +			if (ret)
> +				return ret;
> +		}
> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(prep_bam_dma_desc_data);
> +
> +/*
> + * read_reg_dma:	prepares a descriptor to read a given number of
> + *			contiguous registers to the reg_read_buf pointer
> + *
> + * @first:		offset of the first register in the contiguous block
> + * @num_regs:		number of registers to read
> + * @flags:		flags to control DMA descriptor preparation
> + */
> +int read_reg_dma(struct qcom_nand_controller *nandc, int first,
> +		 int num_regs, unsigned int flags)
> +{
> +	bool flow_control = false;
> +	void *vaddr;
> +
> +	vaddr = nandc->reg_read_buf + nandc->reg_read_pos;
> +	nandc->reg_read_pos += num_regs;
> +
> +	if (first == NAND_DEV_CMD_VLD || first == NAND_DEV_CMD1)
> +		first = dev_cmd_reg_addr(nandc, first);
> +
> +	if (nandc->props->is_bam)
> +		return prep_bam_dma_desc_cmd(nandc, true, first, vaddr,
> +					     num_regs, flags);
> +
> +	if (first == NAND_READ_ID || first == NAND_FLASH_STATUS)
> +		flow_control = true;
> +
> +	return prep_adm_dma_desc(nandc, true, first, vaddr,
> +				 num_regs * sizeof(u32), flow_control);
> +}
> +EXPORT_SYMBOL(read_reg_dma);
> +
> +/*
> + * write_reg_dma:	prepares a descriptor to write a given number of
> + *			contiguous registers
> + *
> + * @first:		offset of the first register in the contiguous block
> + * @num_regs:		number of registers to write
> + * @flags:		flags to control DMA descriptor preparation
> + */
> +int write_reg_dma(struct qcom_nand_controller *nandc, int first,
> +		  int num_regs, unsigned int flags)
> +{
> +	bool flow_control = false;
> +	struct nandc_regs *regs = nandc->regs;
> +	void *vaddr;
> +
> +	vaddr = offset_to_nandc_reg(regs, first);
> +
> +	if (first == NAND_ERASED_CW_DETECT_CFG) {
> +		if (flags & NAND_ERASED_CW_SET)
> +			vaddr = &regs->erased_cw_detect_cfg_set;
> +		else
> +			vaddr = &regs->erased_cw_detect_cfg_clr;
> +	}
> +
> +	if (first == NAND_EXEC_CMD)
> +		flags |= NAND_BAM_NWD;
> +
> +	if (first == NAND_DEV_CMD1_RESTORE || first == NAND_DEV_CMD1)
> +		first = dev_cmd_reg_addr(nandc, NAND_DEV_CMD1);
> +
> +	if (first == NAND_DEV_CMD_VLD_RESTORE || first == NAND_DEV_CMD_VLD)
> +		first = dev_cmd_reg_addr(nandc, NAND_DEV_CMD_VLD);
> +
> +	if (nandc->props->is_bam)
> +		return prep_bam_dma_desc_cmd(nandc, false, first, vaddr,
> +					     num_regs, flags);
> +
> +	if (first == NAND_FLASH_CMD)
> +		flow_control = true;
> +
> +	return prep_adm_dma_desc(nandc, false, first, vaddr,
> +				 num_regs * sizeof(u32), flow_control);
> +}
> +EXPORT_SYMBOL(write_reg_dma);
> +
> +/*
> + * read_data_dma:	prepares a DMA descriptor to transfer data from the
> + *			controller's internal buffer to the buffer 'vaddr'
> + *
> + * @reg_off:		offset within the controller's data buffer
> + * @vaddr:		virtual address of the buffer we want to write to
> + * @size:		DMA transaction size in bytes
> + * @flags:		flags to control DMA descriptor preparation
> + */
> +int read_data_dma(struct qcom_nand_controller *nandc, int reg_off,
> +		  const u8 *vaddr, int size, unsigned int flags)
> +{
> +	if (nandc->props->is_bam)
> +		return prep_bam_dma_desc_data(nandc, true, vaddr, size, flags);
> +
> +	return prep_adm_dma_desc(nandc, true, reg_off, vaddr, size, false);
> +}
> +EXPORT_SYMBOL(read_data_dma);
> +
> +/*
> + * write_data_dma:	prepares a DMA descriptor to transfer data from
> + *			'vaddr' to the controller's internal buffer
> + *
> + * @reg_off:		offset within the controller's data buffer
> + * @vaddr:		virtual address of the buffer we want to read from
> + * @size:		DMA transaction size in bytes
> + * @flags:		flags to control DMA descriptor preparation
> + */
> +int write_data_dma(struct qcom_nand_controller *nandc, int reg_off,
> +		   const u8 *vaddr, int size, unsigned int flags)
> +{
> +	if (nandc->props->is_bam)
> +		return prep_bam_dma_desc_data(nandc, false, vaddr, size, flags);
> +
> +	return prep_adm_dma_desc(nandc, false, reg_off, vaddr, size, false);
> +}
> +EXPORT_SYMBOL(write_data_dma);
> +
> +/* Allocates and Initializes the BAM transaction */
> +struct bam_transaction *
> +alloc_bam_transaction(struct qcom_nand_controller *nandc)
> +{
> +	struct bam_transaction *bam_txn;
> +	size_t bam_txn_size;
> +	unsigned int num_cw = nandc->max_cwperpage;
> +	void *bam_txn_buf;
> +
> +	bam_txn_size =
> +		sizeof(*bam_txn) + num_cw *
> +		((sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS) +
> +		(sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL) +
> +		(sizeof(*bam_txn->data_sgl) * QPIC_PER_CW_DATA_SGL));
> +
> +	bam_txn_buf = devm_kzalloc(nandc->dev, bam_txn_size, GFP_KERNEL);
> +	if (!bam_txn_buf)
> +		return NULL;
> +
> +	bam_txn = bam_txn_buf;
> +	bam_txn_buf += sizeof(*bam_txn);
> +
> +	bam_txn->bam_ce = bam_txn_buf;
> +	bam_txn_buf +=
> +		sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS * num_cw;
> +
> +	bam_txn->cmd_sgl = bam_txn_buf;
> +	bam_txn_buf +=
> +		sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL * num_cw;
> +
> +	bam_txn->data_sgl = bam_txn_buf;
> +
> +	init_completion(&bam_txn->txn_done);
> +
> +	return bam_txn;
> +}
> +EXPORT_SYMBOL(alloc_bam_transaction);
> +
> +/* Clears the BAM transaction indexes */
> +void clear_bam_transaction(struct qcom_nand_controller *nandc)
> +{
> +	struct bam_transaction *bam_txn = nandc->bam_txn;
> +
> +	if (!nandc->props->is_bam)
> +		return;
> +
> +	bam_txn->bam_ce_pos = 0;
> +	bam_txn->bam_ce_start = 0;
> +	bam_txn->cmd_sgl_pos = 0;
> +	bam_txn->cmd_sgl_start = 0;
> +	bam_txn->tx_sgl_pos = 0;
> +	bam_txn->tx_sgl_start = 0;
> +	bam_txn->rx_sgl_pos = 0;
> +	bam_txn->rx_sgl_start = 0;
> +	bam_txn->last_data_desc = NULL;
> +	bam_txn->wait_second_completion = false;
> +
> +	sg_init_table(bam_txn->cmd_sgl, nandc->max_cwperpage *
> +		      QPIC_PER_CW_CMD_SGL);
> +	sg_init_table(bam_txn->data_sgl, nandc->max_cwperpage *
> +		      QPIC_PER_CW_DATA_SGL);
> +
> +	reinit_completion(&bam_txn->txn_done);
> +}
> +EXPORT_SYMBOL(clear_bam_transaction);
> +
> +void qcom_nandc_unalloc(struct qcom_nand_controller *nandc)
> +{
> +	if (nandc->props->is_bam) {
> +		if (!dma_mapping_error(nandc->dev, nandc->reg_read_dma))
> +			dma_unmap_single(nandc->dev, nandc->reg_read_dma,
> +					 MAX_REG_RD *
> +					 sizeof(*nandc->reg_read_buf),
> +					 DMA_FROM_DEVICE);
> +
> +		if (nandc->tx_chan)
> +			dma_release_channel(nandc->tx_chan);
> +
> +		if (nandc->rx_chan)
> +			dma_release_channel(nandc->rx_chan);
> +
> +		if (nandc->cmd_chan)
> +			dma_release_channel(nandc->cmd_chan);
> +	} else {
> +		if (nandc->chan)
> +			dma_release_channel(nandc->chan);
> +	}
> +}
> +EXPORT_SYMBOL(qcom_nandc_unalloc);
> +
> +int qcom_nandc_alloc(struct qcom_nand_controller *nandc)
> +{
> +	int ret;
> +
> +	ret = dma_set_coherent_mask(nandc->dev, DMA_BIT_MASK(32));
> +	if (ret) {
> +		dev_err(nandc->dev, "failed to set DMA mask\n");
> +		return ret;
> +	}
> +
> +	/*
> +	 * we use the internal buffer for reading ONFI params, reading small
> +	 * data like ID and status, and preforming read-copy-write operations
> +	 * when writing to a codeword partially. 532 is the maximum possible
> +	 * size of a codeword for our nand controller
> +	 */
> +	nandc->buf_size = 532;
> +
> +	nandc->data_buffer = devm_kzalloc(nandc->dev, nandc->buf_size, GFP_KERNEL);
> +	if (!nandc->data_buffer)
> +		return -ENOMEM;
> +
> +	nandc->regs = devm_kzalloc(nandc->dev, sizeof(*nandc->regs), GFP_KERNEL);
> +	if (!nandc->regs)
> +		return -ENOMEM;
> +
> +	nandc->reg_read_buf = devm_kcalloc(nandc->dev, MAX_REG_RD,
> +					   sizeof(*nandc->reg_read_buf),
> +					   GFP_KERNEL);
> +	if (!nandc->reg_read_buf)
> +		return -ENOMEM;
> +
> +	if (nandc->props->is_bam) {
> +		nandc->reg_read_dma =
> +			dma_map_single(nandc->dev, nandc->reg_read_buf,
> +				       MAX_REG_RD *
> +				       sizeof(*nandc->reg_read_buf),
> +				       DMA_FROM_DEVICE);
> +		if (dma_mapping_error(nandc->dev, nandc->reg_read_dma)) {
> +			dev_err(nandc->dev, "failed to DMA MAP reg buffer\n");
> +			return -EIO;
> +		}
> +
> +		nandc->tx_chan = dma_request_chan(nandc->dev, "tx");
> +		if (IS_ERR(nandc->tx_chan)) {
> +			ret = PTR_ERR(nandc->tx_chan);
> +			nandc->tx_chan = NULL;
> +			dev_err_probe(nandc->dev, ret,
> +				      "tx DMA channel request failed\n");
> +			goto unalloc;
> +		}
> +
> +		nandc->rx_chan = dma_request_chan(nandc->dev, "rx");
> +		if (IS_ERR(nandc->rx_chan)) {
> +			ret = PTR_ERR(nandc->rx_chan);
> +			nandc->rx_chan = NULL;
> +			dev_err_probe(nandc->dev, ret,
> +				      "rx DMA channel request failed\n");
> +			goto unalloc;
> +		}
> +
> +		nandc->cmd_chan = dma_request_chan(nandc->dev, "cmd");
> +		if (IS_ERR(nandc->cmd_chan)) {
> +			ret = PTR_ERR(nandc->cmd_chan);
> +			nandc->cmd_chan = NULL;
> +			dev_err_probe(nandc->dev, ret,
> +				      "cmd DMA channel request failed\n");
> +			goto unalloc;
> +		}
> +
> +		/*
> +		 * Initially allocate BAM transaction to read ONFI param page.
> +		 * After detecting all the devices, this BAM transaction will
> +		 * be freed and the next BAM transaction will be allocated with
> +		 * maximum codeword size
> +		 */
> +		nandc->max_cwperpage = 1;
> +		nandc->bam_txn = alloc_bam_transaction(nandc);
> +		if (!nandc->bam_txn) {
> +			dev_err(nandc->dev,
> +				"failed to allocate bam transaction\n");
> +			ret = -ENOMEM;
> +			goto unalloc;
> +		}
> +	} else {
> +		nandc->chan = dma_request_chan(nandc->dev, "rxtx");
> +		if (IS_ERR(nandc->chan)) {
> +			ret = PTR_ERR(nandc->chan);
> +			nandc->chan = NULL;
> +			dev_err_probe(nandc->dev, ret,
> +				      "rxtx DMA channel request failed\n");
> +			return ret;
> +		}
> +	}
> +
> +	INIT_LIST_HEAD(&nandc->desc_list);
> +	INIT_LIST_HEAD(&nandc->host_list);
> +
> +	return 0;
> +unalloc:
> +	qcom_nandc_unalloc(nandc);
> +	return ret;
> +}
> +EXPORT_SYMBOL(qcom_nandc_alloc);
> diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
> index b079605c84d3..75c6ca698c85 100644
> --- a/drivers/mtd/nand/raw/qcom_nandc.c
> +++ b/drivers/mtd/nand/raw/qcom_nandc.c
> @@ -2,186 +2,7 @@
>   /*
>    * Copyright (c) 2016, The Linux Foundation. All rights reserved.
>    */
> -#include <linux/bitops.h>
> -#include <linux/clk.h>
> -#include <linux/delay.h>
> -#include <linux/dmaengine.h>
> -#include <linux/dma-mapping.h>
> -#include <linux/dma/qcom_adm.h>
> -#include <linux/dma/qcom_bam_dma.h>
> -#include <linux/module.h>
> -#include <linux/mtd/partitions.h>
> -#include <linux/mtd/rawnand.h>
> -#include <linux/of.h>
> -#include <linux/platform_device.h>
> -#include <linux/slab.h>
> -
> -/* NANDc reg offsets */
> -#define	NAND_FLASH_CMD			0x00
> -#define	NAND_ADDR0			0x04
> -#define	NAND_ADDR1			0x08
> -#define	NAND_FLASH_CHIP_SELECT		0x0c
> -#define	NAND_EXEC_CMD			0x10
> -#define	NAND_FLASH_STATUS		0x14
> -#define	NAND_BUFFER_STATUS		0x18
> -#define	NAND_DEV0_CFG0			0x20
> -#define	NAND_DEV0_CFG1			0x24
> -#define	NAND_DEV0_ECC_CFG		0x28
> -#define	NAND_AUTO_STATUS_EN		0x2c
> -#define	NAND_DEV1_CFG0			0x30
> -#define	NAND_DEV1_CFG1			0x34
> -#define	NAND_READ_ID			0x40
> -#define	NAND_READ_STATUS		0x44
> -#define	NAND_DEV_CMD0			0xa0
> -#define	NAND_DEV_CMD1			0xa4
> -#define	NAND_DEV_CMD2			0xa8
> -#define	NAND_DEV_CMD_VLD		0xac
> -#define	SFLASHC_BURST_CFG		0xe0
> -#define	NAND_ERASED_CW_DETECT_CFG	0xe8
> -#define	NAND_ERASED_CW_DETECT_STATUS	0xec
> -#define	NAND_EBI2_ECC_BUF_CFG		0xf0
> -#define	FLASH_BUF_ACC			0x100
> -
> -#define	NAND_CTRL			0xf00
> -#define	NAND_VERSION			0xf08
> -#define	NAND_READ_LOCATION_0		0xf20
> -#define	NAND_READ_LOCATION_1		0xf24
> -#define	NAND_READ_LOCATION_2		0xf28
> -#define	NAND_READ_LOCATION_3		0xf2c
> -#define	NAND_READ_LOCATION_LAST_CW_0	0xf40
> -#define	NAND_READ_LOCATION_LAST_CW_1	0xf44
> -#define	NAND_READ_LOCATION_LAST_CW_2	0xf48
> -#define	NAND_READ_LOCATION_LAST_CW_3	0xf4c
> -
> -/* dummy register offsets, used by write_reg_dma */
> -#define	NAND_DEV_CMD1_RESTORE		0xdead
> -#define	NAND_DEV_CMD_VLD_RESTORE	0xbeef
> -
> -/* NAND_FLASH_CMD bits */
> -#define	PAGE_ACC			BIT(4)
> -#define	LAST_PAGE			BIT(5)
> -
> -/* NAND_FLASH_CHIP_SELECT bits */
> -#define	NAND_DEV_SEL			0
> -#define	DM_EN				BIT(2)
> -
> -/* NAND_FLASH_STATUS bits */
> -#define	FS_OP_ERR			BIT(4)
> -#define	FS_READY_BSY_N			BIT(5)
> -#define	FS_MPU_ERR			BIT(8)
> -#define	FS_DEVICE_STS_ERR		BIT(16)
> -#define	FS_DEVICE_WP			BIT(23)
> -
> -/* NAND_BUFFER_STATUS bits */
> -#define	BS_UNCORRECTABLE_BIT		BIT(8)
> -#define	BS_CORRECTABLE_ERR_MSK		0x1f
> -
> -/* NAND_DEVn_CFG0 bits */
> -#define	DISABLE_STATUS_AFTER_WRITE	4
> -#define	CW_PER_PAGE			6
> -#define	UD_SIZE_BYTES			9
> -#define	UD_SIZE_BYTES_MASK		GENMASK(18, 9)
> -#define	ECC_PARITY_SIZE_BYTES_RS	19
> -#define	SPARE_SIZE_BYTES		23
> -#define	SPARE_SIZE_BYTES_MASK		GENMASK(26, 23)
> -#define	NUM_ADDR_CYCLES			27
> -#define	STATUS_BFR_READ			30
> -#define	SET_RD_MODE_AFTER_STATUS	31
> -
> -/* NAND_DEVn_CFG0 bits */
> -#define	DEV0_CFG1_ECC_DISABLE		0
> -#define	WIDE_FLASH			1
> -#define	NAND_RECOVERY_CYCLES		2
> -#define	CS_ACTIVE_BSY			5
> -#define	BAD_BLOCK_BYTE_NUM		6
> -#define	BAD_BLOCK_IN_SPARE_AREA		16
> -#define	WR_RD_BSY_GAP			17
> -#define	ENABLE_BCH_ECC			27
> -
> -/* NAND_DEV0_ECC_CFG bits */
> -#define	ECC_CFG_ECC_DISABLE		0
> -#define	ECC_SW_RESET			1
> -#define	ECC_MODE			4
> -#define	ECC_PARITY_SIZE_BYTES_BCH	8
> -#define	ECC_NUM_DATA_BYTES		16
> -#define	ECC_NUM_DATA_BYTES_MASK		GENMASK(25, 16)
> -#define	ECC_FORCE_CLK_OPEN		30
> -
> -/* NAND_DEV_CMD1 bits */
> -#define	READ_ADDR			0
> -
> -/* NAND_DEV_CMD_VLD bits */
> -#define	READ_START_VLD			BIT(0)
> -#define	READ_STOP_VLD			BIT(1)
> -#define	WRITE_START_VLD			BIT(2)
> -#define	ERASE_START_VLD			BIT(3)
> -#define	SEQ_READ_START_VLD		BIT(4)
> -
> -/* NAND_EBI2_ECC_BUF_CFG bits */
> -#define	NUM_STEPS			0
> -
> -/* NAND_ERASED_CW_DETECT_CFG bits */
> -#define	ERASED_CW_ECC_MASK		1
> -#define	AUTO_DETECT_RES			0
> -#define	MASK_ECC			BIT(ERASED_CW_ECC_MASK)
> -#define	RESET_ERASED_DET		BIT(AUTO_DETECT_RES)
> -#define	ACTIVE_ERASED_DET		(0 << AUTO_DETECT_RES)
> -#define	CLR_ERASED_PAGE_DET		(RESET_ERASED_DET | MASK_ECC)
> -#define	SET_ERASED_PAGE_DET		(ACTIVE_ERASED_DET | MASK_ECC)
> -
> -/* NAND_ERASED_CW_DETECT_STATUS bits */
> -#define	PAGE_ALL_ERASED			BIT(7)
> -#define	CODEWORD_ALL_ERASED		BIT(6)
> -#define	PAGE_ERASED			BIT(5)
> -#define	CODEWORD_ERASED			BIT(4)
> -#define	ERASED_PAGE			(PAGE_ALL_ERASED | PAGE_ERASED)
> -#define	ERASED_CW			(CODEWORD_ALL_ERASED | CODEWORD_ERASED)
> -
> -/* NAND_READ_LOCATION_n bits */
> -#define READ_LOCATION_OFFSET		0
> -#define READ_LOCATION_SIZE		16
> -#define READ_LOCATION_LAST		31
> -
> -/* Version Mask */
> -#define	NAND_VERSION_MAJOR_MASK		0xf0000000
> -#define	NAND_VERSION_MAJOR_SHIFT	28
> -#define	NAND_VERSION_MINOR_MASK		0x0fff0000
> -#define	NAND_VERSION_MINOR_SHIFT	16
> -
> -/* NAND OP_CMDs */
> -#define	OP_PAGE_READ			0x2
> -#define	OP_PAGE_READ_WITH_ECC		0x3
> -#define	OP_PAGE_READ_WITH_ECC_SPARE	0x4
> -#define	OP_PAGE_READ_ONFI_READ		0x5
> -#define	OP_PROGRAM_PAGE			0x6
> -#define	OP_PAGE_PROGRAM_WITH_ECC	0x7
> -#define	OP_PROGRAM_PAGE_SPARE		0x9
> -#define	OP_BLOCK_ERASE			0xa
> -#define	OP_CHECK_STATUS			0xc
> -#define	OP_FETCH_ID			0xb
> -#define	OP_RESET_DEVICE			0xd
> -
> -/* Default Value for NAND_DEV_CMD_VLD */
> -#define NAND_DEV_CMD_VLD_VAL		(READ_START_VLD | WRITE_START_VLD | \
> -					 ERASE_START_VLD | SEQ_READ_START_VLD)
> -
> -/* NAND_CTRL bits */
> -#define	BAM_MODE_EN			BIT(0)
> -
> -/*
> - * the NAND controller performs reads/writes with ECC in 516 byte chunks.
> - * the driver calls the chunks 'step' or 'codeword' interchangeably
> - */
> -#define	NANDC_STEP_SIZE			512
> -
> -/*
> - * the largest page size we support is 8K, this will have 16 steps/codewords
> - * of 512 bytes each
> - */
> -#define	MAX_NUM_STEPS			(SZ_8K / NANDC_STEP_SIZE)
> -
> -/* we read at most 3 registers per codeword scan */
> -#define	MAX_REG_RD			(3 * MAX_NUM_STEPS)
> +#include <linux/mtd/nand-qpic-common.h>
>   
>   /* ECC modes supported by the controller */
>   #define	ECC_NONE	BIT(0)
> @@ -200,247 +21,6 @@ nandc_set_reg(chip, reg,			\
>   	      ((cw_offset) << READ_LOCATION_OFFSET) |		\
>   	      ((read_size) << READ_LOCATION_SIZE) |			\
>   	      ((is_last_read_loc) << READ_LOCATION_LAST))
> -/*
> - * Returns the actual register address for all NAND_DEV_ registers
> - * (i.e. NAND_DEV_CMD0, NAND_DEV_CMD1, NAND_DEV_CMD2 and NAND_DEV_CMD_VLD)
> - */
> -#define dev_cmd_reg_addr(nandc, reg) ((nandc)->props->dev_cmd_reg_start + (reg))
> -
> -/* Returns the NAND register physical address */
> -#define nandc_reg_phys(chip, offset) ((chip)->base_phys + (offset))
> -
> -/* Returns the dma address for reg read buffer */
> -#define reg_buf_dma_addr(chip, vaddr) \
> -	((chip)->reg_read_dma + \
> -	((u8 *)(vaddr) - (u8 *)(chip)->reg_read_buf))
> -
> -#define QPIC_PER_CW_CMD_ELEMENTS	32
> -#define QPIC_PER_CW_CMD_SGL		32
> -#define QPIC_PER_CW_DATA_SGL		8
> -
> -#define QPIC_NAND_COMPLETION_TIMEOUT	msecs_to_jiffies(2000)
> -
> -/*
> - * Flags used in DMA descriptor preparation helper functions
> - * (i.e. read_reg_dma/write_reg_dma/read_data_dma/write_data_dma)
> - */
> -/* Don't set the EOT in current tx BAM sgl */
> -#define NAND_BAM_NO_EOT			BIT(0)
> -/* Set the NWD flag in current BAM sgl */
> -#define NAND_BAM_NWD			BIT(1)
> -/* Finish writing in the current BAM sgl and start writing in another BAM sgl */
> -#define NAND_BAM_NEXT_SGL		BIT(2)
> -/*
> - * Erased codeword status is being used two times in single transfer so this
> - * flag will determine the current value of erased codeword status register
> - */
> -#define NAND_ERASED_CW_SET		BIT(4)
> -
> -#define MAX_ADDRESS_CYCLE		5
> -
> -/*
> - * This data type corresponds to the BAM transaction which will be used for all
> - * NAND transfers.
> - * @bam_ce - the array of BAM command elements
> - * @cmd_sgl - sgl for NAND BAM command pipe
> - * @data_sgl - sgl for NAND BAM consumer/producer pipe
> - * @last_data_desc - last DMA desc in data channel (tx/rx).
> - * @last_cmd_desc - last DMA desc in command channel.
> - * @txn_done - completion for NAND transfer.
> - * @bam_ce_pos - the index in bam_ce which is available for next sgl
> - * @bam_ce_start - the index in bam_ce which marks the start position ce
> - *		   for current sgl. It will be used for size calculation
> - *		   for current sgl
> - * @cmd_sgl_pos - current index in command sgl.
> - * @cmd_sgl_start - start index in command sgl.
> - * @tx_sgl_pos - current index in data sgl for tx.
> - * @tx_sgl_start - start index in data sgl for tx.
> - * @rx_sgl_pos - current index in data sgl for rx.
> - * @rx_sgl_start - start index in data sgl for rx.
> - * @wait_second_completion - wait for second DMA desc completion before making
> - *			     the NAND transfer completion.
> - */
> -struct bam_transaction {
> -	struct bam_cmd_element *bam_ce;
> -	struct scatterlist *cmd_sgl;
> -	struct scatterlist *data_sgl;
> -	struct dma_async_tx_descriptor *last_data_desc;
> -	struct dma_async_tx_descriptor *last_cmd_desc;
> -	struct completion txn_done;
> -	u32 bam_ce_pos;
> -	u32 bam_ce_start;
> -	u32 cmd_sgl_pos;
> -	u32 cmd_sgl_start;
> -	u32 tx_sgl_pos;
> -	u32 tx_sgl_start;
> -	u32 rx_sgl_pos;
> -	u32 rx_sgl_start;
> -	bool wait_second_completion;
> -};
> -
> -/*
> - * This data type corresponds to the nand dma descriptor
> - * @dma_desc - low level DMA engine descriptor
> - * @list - list for desc_info
> - *
> - * @adm_sgl - sgl which will be used for single sgl dma descriptor. Only used by
> - *	      ADM
> - * @bam_sgl - sgl which will be used for dma descriptor. Only used by BAM
> - * @sgl_cnt - number of SGL in bam_sgl. Only used by BAM
> - * @dir - DMA transfer direction
> - */
> -struct desc_info {
> -	struct dma_async_tx_descriptor *dma_desc;
> -	struct list_head node;
> -
> -	union {
> -		struct scatterlist adm_sgl;
> -		struct {
> -			struct scatterlist *bam_sgl;
> -			int sgl_cnt;
> -		};
> -	};
> -	enum dma_data_direction dir;
> -};
> -
> -/*
> - * holds the current register values that we want to write. acts as a contiguous
> - * chunk of memory which we use to write the controller registers through DMA.
> - */
> -struct nandc_regs {
> -	__le32 cmd;
> -	__le32 addr0;
> -	__le32 addr1;
> -	__le32 chip_sel;
> -	__le32 exec;
> -
> -	__le32 cfg0;
> -	__le32 cfg1;
> -	__le32 ecc_bch_cfg;
> -
> -	__le32 clrflashstatus;
> -	__le32 clrreadstatus;
> -
> -	__le32 cmd1;
> -	__le32 vld;
> -
> -	__le32 orig_cmd1;
> -	__le32 orig_vld;
> -
> -	__le32 ecc_buf_cfg;
> -	__le32 read_location0;
> -	__le32 read_location1;
> -	__le32 read_location2;
> -	__le32 read_location3;
> -	__le32 read_location_last0;
> -	__le32 read_location_last1;
> -	__le32 read_location_last2;
> -	__le32 read_location_last3;
> -
> -	__le32 erased_cw_detect_cfg_clr;
> -	__le32 erased_cw_detect_cfg_set;
> -};
> -
> -/*
> - * NAND controller data struct
> - *
> - * @dev:			parent device
> - *
> - * @base:			MMIO base
> - *
> - * @core_clk:			controller clock
> - * @aon_clk:			another controller clock
> - *
> - * @regs:			a contiguous chunk of memory for DMA register
> - *				writes. contains the register values to be
> - *				written to controller
> - *
> - * @props:			properties of current NAND controller,
> - *				initialized via DT match data
> - *
> - * @controller:			base controller structure
> - * @host_list:			list containing all the chips attached to the
> - *				controller
> - *
> - * @chan:			dma channel
> - * @cmd_crci:			ADM DMA CRCI for command flow control
> - * @data_crci:			ADM DMA CRCI for data flow control
> - *
> - * @desc_list:			DMA descriptor list (list of desc_infos)
> - *
> - * @data_buffer:		our local DMA buffer for page read/writes,
> - *				used when we can't use the buffer provided
> - *				by upper layers directly
> - * @reg_read_buf:		local buffer for reading back registers via DMA
> - *
> - * @base_phys:			physical base address of controller registers
> - * @base_dma:			dma base address of controller registers
> - * @reg_read_dma:		contains dma address for register read buffer
> - *
> - * @buf_size/count/start:	markers for chip->legacy.read_buf/write_buf
> - *				functions
> - * @max_cwperpage:		maximum QPIC codewords required. calculated
> - *				from all connected NAND devices pagesize
> - *
> - * @reg_read_pos:		marker for data read in reg_read_buf
> - *
> - * @cmd1/vld:			some fixed controller register values
> - *
> - * @exec_opwrite:		flag to select correct number of code word
> - *				while reading status
> - */
> -struct qcom_nand_controller {
> -	struct device *dev;
> -
> -	void __iomem *base;
> -
> -	struct clk *core_clk;
> -	struct clk *aon_clk;
> -
> -	struct nandc_regs *regs;
> -	struct bam_transaction *bam_txn;
> -
> -	const struct qcom_nandc_props *props;
> -
> -	struct nand_controller controller;
> -	struct list_head host_list;
> -
> -	union {
> -		/* will be used only by QPIC for BAM DMA */
> -		struct {
> -			struct dma_chan *tx_chan;
> -			struct dma_chan *rx_chan;
> -			struct dma_chan *cmd_chan;
> -		};
> -
> -		/* will be used only by EBI2 for ADM DMA */
> -		struct {
> -			struct dma_chan *chan;
> -			unsigned int cmd_crci;
> -			unsigned int data_crci;
> -		};
> -	};
> -
> -	struct list_head desc_list;
> -
> -	u8		*data_buffer;
> -	__le32		*reg_read_buf;
> -
> -	phys_addr_t base_phys;
> -	dma_addr_t base_dma;
> -	dma_addr_t reg_read_dma;
> -
> -	int		buf_size;
> -	int		buf_count;
> -	int		buf_start;
> -	unsigned int	max_cwperpage;
> -
> -	int reg_read_pos;
> -
> -	u32 cmd1, vld;
> -	bool exec_opwrite;
> -};
> -
>   /*
>    * NAND special boot partitions
>    *
> @@ -544,113 +124,17 @@ struct qcom_nand_host {
>   	bool bch_enabled;
>   };
>   
> -/*
> - * This data type corresponds to the NAND controller properties which varies
> - * among different NAND controllers.
> - * @ecc_modes - ecc mode for NAND
> - * @dev_cmd_reg_start - NAND_DEV_CMD_* registers starting offset
> - * @is_bam - whether NAND controller is using BAM
> - * @is_qpic - whether NAND CTRL is part of qpic IP
> - * @qpic_v2 - flag to indicate QPIC IP version 2
> - * @use_codeword_fixup - whether NAND has different layout for boot partitions
> - */
> -struct qcom_nandc_props {
> -	u32 ecc_modes;
> -	u32 dev_cmd_reg_start;
> -	bool is_bam;
> -	bool is_qpic;
> -	bool qpic_v2;
> -	bool use_codeword_fixup;
> -};
> -
> -/* Frees the BAM transaction memory */
> -static void free_bam_transaction(struct qcom_nand_controller *nandc)
> -{
> -	struct bam_transaction *bam_txn = nandc->bam_txn;
> -
> -	devm_kfree(nandc->dev, bam_txn);
> -}
> -
> -/* Allocates and Initializes the BAM transaction */
> -static struct bam_transaction *
> -alloc_bam_transaction(struct qcom_nand_controller *nandc)
> -{
> -	struct bam_transaction *bam_txn;
> -	size_t bam_txn_size;
> -	unsigned int num_cw = nandc->max_cwperpage;
> -	void *bam_txn_buf;
> -
> -	bam_txn_size =
> -		sizeof(*bam_txn) + num_cw *
> -		((sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS) +
> -		(sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL) +
> -		(sizeof(*bam_txn->data_sgl) * QPIC_PER_CW_DATA_SGL));
> -
> -	bam_txn_buf = devm_kzalloc(nandc->dev, bam_txn_size, GFP_KERNEL);
> -	if (!bam_txn_buf)
> -		return NULL;
> -
> -	bam_txn = bam_txn_buf;
> -	bam_txn_buf += sizeof(*bam_txn);
> -
> -	bam_txn->bam_ce = bam_txn_buf;
> -	bam_txn_buf +=
> -		sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS * num_cw;
> -
> -	bam_txn->cmd_sgl = bam_txn_buf;
> -	bam_txn_buf +=
> -		sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL * num_cw;
> -
> -	bam_txn->data_sgl = bam_txn_buf;
> -
> -	init_completion(&bam_txn->txn_done);
> -
> -	return bam_txn;
> -}
> -
> -/* Clears the BAM transaction indexes */
> -static void clear_bam_transaction(struct qcom_nand_controller *nandc)
> +static void nandc_set_reg(struct nand_chip *chip, int offset,
> +			  u32 val)
>   {
> -	struct bam_transaction *bam_txn = nandc->bam_txn;
> -
> -	if (!nandc->props->is_bam)
> -		return;
> -
> -	bam_txn->bam_ce_pos = 0;
> -	bam_txn->bam_ce_start = 0;
> -	bam_txn->cmd_sgl_pos = 0;
> -	bam_txn->cmd_sgl_start = 0;
> -	bam_txn->tx_sgl_pos = 0;
> -	bam_txn->tx_sgl_start = 0;
> -	bam_txn->rx_sgl_pos = 0;
> -	bam_txn->rx_sgl_start = 0;
> -	bam_txn->last_data_desc = NULL;
> -	bam_txn->wait_second_completion = false;
> -
> -	sg_init_table(bam_txn->cmd_sgl, nandc->max_cwperpage *
> -		      QPIC_PER_CW_CMD_SGL);
> -	sg_init_table(bam_txn->data_sgl, nandc->max_cwperpage *
> -		      QPIC_PER_CW_DATA_SGL);
> -
> -	reinit_completion(&bam_txn->txn_done);
> -}
> +	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
> +	struct nandc_regs *regs = nandc->regs;
> +	__le32 *reg;
>   
> -/* Callback for DMA descriptor completion */
> -static void qpic_bam_dma_done(void *data)
> -{
> -	struct bam_transaction *bam_txn = data;
> +	reg = offset_to_nandc_reg(regs, offset);
>   
> -	/*
> -	 * In case of data transfer with NAND, 2 callbacks will be generated.
> -	 * One for command channel and another one for data channel.
> -	 * If current transaction has data descriptors
> -	 * (i.e. wait_second_completion is true), then set this to false
> -	 * and wait for second DMA descriptor completion.
> -	 */
> -	if (bam_txn->wait_second_completion)
> -		bam_txn->wait_second_completion = false;
> -	else
> -		complete(&bam_txn->txn_done);
> +	if (reg)
> +		*reg = cpu_to_le32(val);
>   }
>   
>   static inline struct qcom_nand_host *to_qcom_nand_host(struct nand_chip *chip)
> @@ -658,13 +142,6 @@ static inline struct qcom_nand_host *to_qcom_nand_host(struct nand_chip *chip)
>   	return container_of(chip, struct qcom_nand_host, chip);
>   }
>   
> -static inline struct qcom_nand_controller *
> -get_qcom_nand_controller(struct nand_chip *chip)
> -{
> -	return container_of(chip->controller, struct qcom_nand_controller,
> -			    controller);
> -}
> -
>   static inline u32 nandc_read(struct qcom_nand_controller *nandc, int offset)
>   {
>   	return ioread32(nandc->base + offset);
> @@ -676,91 +153,6 @@ static inline void nandc_write(struct qcom_nand_controller *nandc, int offset,
>   	iowrite32(val, nandc->base + offset);
>   }
>   
> -static inline void nandc_read_buffer_sync(struct qcom_nand_controller *nandc,
> -					  bool is_cpu)
> -{
> -	if (!nandc->props->is_bam)
> -		return;
> -
> -	if (is_cpu)
> -		dma_sync_single_for_cpu(nandc->dev, nandc->reg_read_dma,
> -					MAX_REG_RD *
> -					sizeof(*nandc->reg_read_buf),
> -					DMA_FROM_DEVICE);
> -	else
> -		dma_sync_single_for_device(nandc->dev, nandc->reg_read_dma,
> -					   MAX_REG_RD *
> -					   sizeof(*nandc->reg_read_buf),
> -					   DMA_FROM_DEVICE);
> -}
> -
> -static __le32 *offset_to_nandc_reg(struct nandc_regs *regs, int offset)
> -{
> -	switch (offset) {
> -	case NAND_FLASH_CMD:
> -		return &regs->cmd;
> -	case NAND_ADDR0:
> -		return &regs->addr0;
> -	case NAND_ADDR1:
> -		return &regs->addr1;
> -	case NAND_FLASH_CHIP_SELECT:
> -		return &regs->chip_sel;
> -	case NAND_EXEC_CMD:
> -		return &regs->exec;
> -	case NAND_FLASH_STATUS:
> -		return &regs->clrflashstatus;
> -	case NAND_DEV0_CFG0:
> -		return &regs->cfg0;
> -	case NAND_DEV0_CFG1:
> -		return &regs->cfg1;
> -	case NAND_DEV0_ECC_CFG:
> -		return &regs->ecc_bch_cfg;
> -	case NAND_READ_STATUS:
> -		return &regs->clrreadstatus;
> -	case NAND_DEV_CMD1:
> -		return &regs->cmd1;
> -	case NAND_DEV_CMD1_RESTORE:
> -		return &regs->orig_cmd1;
> -	case NAND_DEV_CMD_VLD:
> -		return &regs->vld;
> -	case NAND_DEV_CMD_VLD_RESTORE:
> -		return &regs->orig_vld;
> -	case NAND_EBI2_ECC_BUF_CFG:
> -		return &regs->ecc_buf_cfg;
> -	case NAND_READ_LOCATION_0:
> -		return &regs->read_location0;
> -	case NAND_READ_LOCATION_1:
> -		return &regs->read_location1;
> -	case NAND_READ_LOCATION_2:
> -		return &regs->read_location2;
> -	case NAND_READ_LOCATION_3:
> -		return &regs->read_location3;
> -	case NAND_READ_LOCATION_LAST_CW_0:
> -		return &regs->read_location_last0;
> -	case NAND_READ_LOCATION_LAST_CW_1:
> -		return &regs->read_location_last1;
> -	case NAND_READ_LOCATION_LAST_CW_2:
> -		return &regs->read_location_last2;
> -	case NAND_READ_LOCATION_LAST_CW_3:
> -		return &regs->read_location_last3;
> -	default:
> -		return NULL;
> -	}
> -}
> -
> -static void nandc_set_reg(struct nand_chip *chip, int offset,
> -			  u32 val)
> -{
> -	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
> -	struct nandc_regs *regs = nandc->regs;
> -	__le32 *reg;
> -
> -	reg = offset_to_nandc_reg(regs, offset);
> -
> -	if (reg)
> -		*reg = cpu_to_le32(val);
> -}
> -
>   /* Helper to check the code word, whether it is last cw or not */
>   static bool qcom_nandc_is_last_cw(struct nand_ecc_ctrl *ecc, int cw)
>   {
> @@ -852,383 +244,6 @@ static void update_rw_regs(struct qcom_nand_host *host, int num_cw, bool read, i
>   				   host->cw_data : host->cw_size, 1);
>   }
>   
> -/*
> - * Maps the scatter gather list for DMA transfer and forms the DMA descriptor
> - * for BAM. This descriptor will be added in the NAND DMA descriptor queue
> - * which will be submitted to DMA engine.
> - */
> -static int prepare_bam_async_desc(struct qcom_nand_controller *nandc,
> -				  struct dma_chan *chan,
> -				  unsigned long flags)
> -{
> -	struct desc_info *desc;
> -	struct scatterlist *sgl;
> -	unsigned int sgl_cnt;
> -	int ret;
> -	struct bam_transaction *bam_txn = nandc->bam_txn;
> -	enum dma_transfer_direction dir_eng;
> -	struct dma_async_tx_descriptor *dma_desc;
> -
> -	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
> -	if (!desc)
> -		return -ENOMEM;
> -
> -	if (chan == nandc->cmd_chan) {
> -		sgl = &bam_txn->cmd_sgl[bam_txn->cmd_sgl_start];
> -		sgl_cnt = bam_txn->cmd_sgl_pos - bam_txn->cmd_sgl_start;
> -		bam_txn->cmd_sgl_start = bam_txn->cmd_sgl_pos;
> -		dir_eng = DMA_MEM_TO_DEV;
> -		desc->dir = DMA_TO_DEVICE;
> -	} else if (chan == nandc->tx_chan) {
> -		sgl = &bam_txn->data_sgl[bam_txn->tx_sgl_start];
> -		sgl_cnt = bam_txn->tx_sgl_pos - bam_txn->tx_sgl_start;
> -		bam_txn->tx_sgl_start = bam_txn->tx_sgl_pos;
> -		dir_eng = DMA_MEM_TO_DEV;
> -		desc->dir = DMA_TO_DEVICE;
> -	} else {
> -		sgl = &bam_txn->data_sgl[bam_txn->rx_sgl_start];
> -		sgl_cnt = bam_txn->rx_sgl_pos - bam_txn->rx_sgl_start;
> -		bam_txn->rx_sgl_start = bam_txn->rx_sgl_pos;
> -		dir_eng = DMA_DEV_TO_MEM;
> -		desc->dir = DMA_FROM_DEVICE;
> -	}
> -
> -	sg_mark_end(sgl + sgl_cnt - 1);
> -	ret = dma_map_sg(nandc->dev, sgl, sgl_cnt, desc->dir);
> -	if (ret == 0) {
> -		dev_err(nandc->dev, "failure in mapping desc\n");
> -		kfree(desc);
> -		return -ENOMEM;
> -	}
> -
> -	desc->sgl_cnt = sgl_cnt;
> -	desc->bam_sgl = sgl;
> -
> -	dma_desc = dmaengine_prep_slave_sg(chan, sgl, sgl_cnt, dir_eng,
> -					   flags);
> -
> -	if (!dma_desc) {
> -		dev_err(nandc->dev, "failure in prep desc\n");
> -		dma_unmap_sg(nandc->dev, sgl, sgl_cnt, desc->dir);
> -		kfree(desc);
> -		return -EINVAL;
> -	}
> -
> -	desc->dma_desc = dma_desc;
> -
> -	/* update last data/command descriptor */
> -	if (chan == nandc->cmd_chan)
> -		bam_txn->last_cmd_desc = dma_desc;
> -	else
> -		bam_txn->last_data_desc = dma_desc;
> -
> -	list_add_tail(&desc->node, &nandc->desc_list);
> -
> -	return 0;
> -}
> -
> -/*
> - * Prepares the command descriptor for BAM DMA which will be used for NAND
> - * register reads and writes. The command descriptor requires the command
> - * to be formed in command element type so this function uses the command
> - * element from bam transaction ce array and fills the same with required
> - * data. A single SGL can contain multiple command elements so
> - * NAND_BAM_NEXT_SGL will be used for starting the separate SGL
> - * after the current command element.
> - */
> -static int prep_bam_dma_desc_cmd(struct qcom_nand_controller *nandc, bool read,
> -				 int reg_off, const void *vaddr,
> -				 int size, unsigned int flags)
> -{
> -	int bam_ce_size;
> -	int i, ret;
> -	struct bam_cmd_element *bam_ce_buffer;
> -	struct bam_transaction *bam_txn = nandc->bam_txn;
> -
> -	bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_pos];
> -
> -	/* fill the command desc */
> -	for (i = 0; i < size; i++) {
> -		if (read)
> -			bam_prep_ce(&bam_ce_buffer[i],
> -				    nandc_reg_phys(nandc, reg_off + 4 * i),
> -				    BAM_READ_COMMAND,
> -				    reg_buf_dma_addr(nandc,
> -						     (__le32 *)vaddr + i));
> -		else
> -			bam_prep_ce_le32(&bam_ce_buffer[i],
> -					 nandc_reg_phys(nandc, reg_off + 4 * i),
> -					 BAM_WRITE_COMMAND,
> -					 *((__le32 *)vaddr + i));
> -	}
> -
> -	bam_txn->bam_ce_pos += size;
> -
> -	/* use the separate sgl after this command */
> -	if (flags & NAND_BAM_NEXT_SGL) {
> -		bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_start];
> -		bam_ce_size = (bam_txn->bam_ce_pos -
> -				bam_txn->bam_ce_start) *
> -				sizeof(struct bam_cmd_element);
> -		sg_set_buf(&bam_txn->cmd_sgl[bam_txn->cmd_sgl_pos],
> -			   bam_ce_buffer, bam_ce_size);
> -		bam_txn->cmd_sgl_pos++;
> -		bam_txn->bam_ce_start = bam_txn->bam_ce_pos;
> -
> -		if (flags & NAND_BAM_NWD) {
> -			ret = prepare_bam_async_desc(nandc, nandc->cmd_chan,
> -						     DMA_PREP_FENCE |
> -						     DMA_PREP_CMD);
> -			if (ret)
> -				return ret;
> -		}
> -	}
> -
> -	return 0;
> -}
> -
> -/*
> - * Prepares the data descriptor for BAM DMA which will be used for NAND
> - * data reads and writes.
> - */
> -static int prep_bam_dma_desc_data(struct qcom_nand_controller *nandc, bool read,
> -				  const void *vaddr,
> -				  int size, unsigned int flags)
> -{
> -	int ret;
> -	struct bam_transaction *bam_txn = nandc->bam_txn;
> -
> -	if (read) {
> -		sg_set_buf(&bam_txn->data_sgl[bam_txn->rx_sgl_pos],
> -			   vaddr, size);
> -		bam_txn->rx_sgl_pos++;
> -	} else {
> -		sg_set_buf(&bam_txn->data_sgl[bam_txn->tx_sgl_pos],
> -			   vaddr, size);
> -		bam_txn->tx_sgl_pos++;
> -
> -		/*
> -		 * BAM will only set EOT for DMA_PREP_INTERRUPT so if this flag
> -		 * is not set, form the DMA descriptor
> -		 */
> -		if (!(flags & NAND_BAM_NO_EOT)) {
> -			ret = prepare_bam_async_desc(nandc, nandc->tx_chan,
> -						     DMA_PREP_INTERRUPT);
> -			if (ret)
> -				return ret;
> -		}
> -	}
> -
> -	return 0;
> -}
> -
> -static int prep_adm_dma_desc(struct qcom_nand_controller *nandc, bool read,
> -			     int reg_off, const void *vaddr, int size,
> -			     bool flow_control)
> -{
> -	struct desc_info *desc;
> -	struct dma_async_tx_descriptor *dma_desc;
> -	struct scatterlist *sgl;
> -	struct dma_slave_config slave_conf;
> -	struct qcom_adm_peripheral_config periph_conf = {};
> -	enum dma_transfer_direction dir_eng;
> -	int ret;
> -
> -	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
> -	if (!desc)
> -		return -ENOMEM;
> -
> -	sgl = &desc->adm_sgl;
> -
> -	sg_init_one(sgl, vaddr, size);
> -
> -	if (read) {
> -		dir_eng = DMA_DEV_TO_MEM;
> -		desc->dir = DMA_FROM_DEVICE;
> -	} else {
> -		dir_eng = DMA_MEM_TO_DEV;
> -		desc->dir = DMA_TO_DEVICE;
> -	}
> -
> -	ret = dma_map_sg(nandc->dev, sgl, 1, desc->dir);
> -	if (ret == 0) {
> -		ret = -ENOMEM;
> -		goto err;
> -	}
> -
> -	memset(&slave_conf, 0x00, sizeof(slave_conf));
> -
> -	slave_conf.device_fc = flow_control;
> -	if (read) {
> -		slave_conf.src_maxburst = 16;
> -		slave_conf.src_addr = nandc->base_dma + reg_off;
> -		if (nandc->data_crci) {
> -			periph_conf.crci = nandc->data_crci;
> -			slave_conf.peripheral_config = &periph_conf;
> -			slave_conf.peripheral_size = sizeof(periph_conf);
> -		}
> -	} else {
> -		slave_conf.dst_maxburst = 16;
> -		slave_conf.dst_addr = nandc->base_dma + reg_off;
> -		if (nandc->cmd_crci) {
> -			periph_conf.crci = nandc->cmd_crci;
> -			slave_conf.peripheral_config = &periph_conf;
> -			slave_conf.peripheral_size = sizeof(periph_conf);
> -		}
> -	}
> -
> -	ret = dmaengine_slave_config(nandc->chan, &slave_conf);
> -	if (ret) {
> -		dev_err(nandc->dev, "failed to configure dma channel\n");
> -		goto err;
> -	}
> -
> -	dma_desc = dmaengine_prep_slave_sg(nandc->chan, sgl, 1, dir_eng, 0);
> -	if (!dma_desc) {
> -		dev_err(nandc->dev, "failed to prepare desc\n");
> -		ret = -EINVAL;
> -		goto err;
> -	}
> -
> -	desc->dma_desc = dma_desc;
> -
> -	list_add_tail(&desc->node, &nandc->desc_list);
> -
> -	return 0;
> -err:
> -	kfree(desc);
> -
> -	return ret;
> -}
> -
> -/*
> - * read_reg_dma:	prepares a descriptor to read a given number of
> - *			contiguous registers to the reg_read_buf pointer
> - *
> - * @first:		offset of the first register in the contiguous block
> - * @num_regs:		number of registers to read
> - * @flags:		flags to control DMA descriptor preparation
> - */
> -static int read_reg_dma(struct qcom_nand_controller *nandc, int first,
> -			int num_regs, unsigned int flags)
> -{
> -	bool flow_control = false;
> -	void *vaddr;
> -
> -	vaddr = nandc->reg_read_buf + nandc->reg_read_pos;
> -	nandc->reg_read_pos += num_regs;
> -
> -	if (first == NAND_DEV_CMD_VLD || first == NAND_DEV_CMD1)
> -		first = dev_cmd_reg_addr(nandc, first);
> -
> -	if (nandc->props->is_bam)
> -		return prep_bam_dma_desc_cmd(nandc, true, first, vaddr,
> -					     num_regs, flags);
> -
> -	if (first == NAND_READ_ID || first == NAND_FLASH_STATUS)
> -		flow_control = true;
> -
> -	return prep_adm_dma_desc(nandc, true, first, vaddr,
> -				 num_regs * sizeof(u32), flow_control);
> -}
> -
> -/*
> - * write_reg_dma:	prepares a descriptor to write a given number of
> - *			contiguous registers
> - *
> - * @first:		offset of the first register in the contiguous block
> - * @num_regs:		number of registers to write
> - * @flags:		flags to control DMA descriptor preparation
> - */
> -static int write_reg_dma(struct qcom_nand_controller *nandc, int first,
> -			 int num_regs, unsigned int flags)
> -{
> -	bool flow_control = false;
> -	struct nandc_regs *regs = nandc->regs;
> -	void *vaddr;
> -
> -	vaddr = offset_to_nandc_reg(regs, first);
> -
> -	if (first == NAND_ERASED_CW_DETECT_CFG) {
> -		if (flags & NAND_ERASED_CW_SET)
> -			vaddr = &regs->erased_cw_detect_cfg_set;
> -		else
> -			vaddr = &regs->erased_cw_detect_cfg_clr;
> -	}
> -
> -	if (first == NAND_EXEC_CMD)
> -		flags |= NAND_BAM_NWD;
> -
> -	if (first == NAND_DEV_CMD1_RESTORE || first == NAND_DEV_CMD1)
> -		first = dev_cmd_reg_addr(nandc, NAND_DEV_CMD1);
> -
> -	if (first == NAND_DEV_CMD_VLD_RESTORE || first == NAND_DEV_CMD_VLD)
> -		first = dev_cmd_reg_addr(nandc, NAND_DEV_CMD_VLD);
> -
> -	if (nandc->props->is_bam)
> -		return prep_bam_dma_desc_cmd(nandc, false, first, vaddr,
> -					     num_regs, flags);
> -
> -	if (first == NAND_FLASH_CMD)
> -		flow_control = true;
> -
> -	return prep_adm_dma_desc(nandc, false, first, vaddr,
> -				 num_regs * sizeof(u32), flow_control);
> -}
> -
> -/*
> - * read_data_dma:	prepares a DMA descriptor to transfer data from the
> - *			controller's internal buffer to the buffer 'vaddr'
> - *
> - * @reg_off:		offset within the controller's data buffer
> - * @vaddr:		virtual address of the buffer we want to write to
> - * @size:		DMA transaction size in bytes
> - * @flags:		flags to control DMA descriptor preparation
> - */
> -static int read_data_dma(struct qcom_nand_controller *nandc, int reg_off,
> -			 const u8 *vaddr, int size, unsigned int flags)
> -{
> -	if (nandc->props->is_bam)
> -		return prep_bam_dma_desc_data(nandc, true, vaddr, size, flags);
> -
> -	return prep_adm_dma_desc(nandc, true, reg_off, vaddr, size, false);
> -}
> -
> -/*
> - * write_data_dma:	prepares a DMA descriptor to transfer data from
> - *			'vaddr' to the controller's internal buffer
> - *
> - * @reg_off:		offset within the controller's data buffer
> - * @vaddr:		virtual address of the buffer we want to read from
> - * @size:		DMA transaction size in bytes
> - * @flags:		flags to control DMA descriptor preparation
> - */
> -static int write_data_dma(struct qcom_nand_controller *nandc, int reg_off,
> -			  const u8 *vaddr, int size, unsigned int flags)
> -{
> -	if (nandc->props->is_bam)
> -		return prep_bam_dma_desc_data(nandc, false, vaddr, size, flags);
> -
> -	return prep_adm_dma_desc(nandc, false, reg_off, vaddr, size, false);
> -}
> -
> -/*
> - * Helper to prepare DMA descriptors for configuring registers
> - * before reading a NAND page.
> - */
> -static void config_nand_page_read(struct nand_chip *chip)
> -{
> -	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
> -
> -	write_reg_dma(nandc, NAND_ADDR0, 2, 0);
> -	write_reg_dma(nandc, NAND_DEV0_CFG0, 3, 0);
> -	if (!nandc->props->qpic_v2)
> -		write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1, 0);
> -	write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1, 0);
> -	write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1,
> -		      NAND_ERASED_CW_SET | NAND_BAM_NEXT_SGL);
> -}
> -
>   /*
>    * Helper to prepare DMA descriptors for configuring registers
>    * before reading each codeword in NAND page.
> @@ -1303,88 +318,6 @@ static void config_nand_cw_write(struct nand_chip *chip)
>   	write_reg_dma(nandc, NAND_READ_STATUS, 1, NAND_BAM_NEXT_SGL);
>   }
>   
> -/* helpers to submit/free our list of dma descriptors */
> -static int submit_descs(struct qcom_nand_controller *nandc)
> -{
> -	struct desc_info *desc, *n;
> -	dma_cookie_t cookie = 0;
> -	struct bam_transaction *bam_txn = nandc->bam_txn;
> -	int ret = 0;
> -
> -	if (nandc->props->is_bam) {
> -		if (bam_txn->rx_sgl_pos > bam_txn->rx_sgl_start) {
> -			ret = prepare_bam_async_desc(nandc, nandc->rx_chan, 0);
> -			if (ret)
> -				goto err_unmap_free_desc;
> -		}
> -
> -		if (bam_txn->tx_sgl_pos > bam_txn->tx_sgl_start) {
> -			ret = prepare_bam_async_desc(nandc, nandc->tx_chan,
> -						   DMA_PREP_INTERRUPT);
> -			if (ret)
> -				goto err_unmap_free_desc;
> -		}
> -
> -		if (bam_txn->cmd_sgl_pos > bam_txn->cmd_sgl_start) {
> -			ret = prepare_bam_async_desc(nandc, nandc->cmd_chan,
> -						   DMA_PREP_CMD);
> -			if (ret)
> -				goto err_unmap_free_desc;
> -		}
> -	}
> -
> -	list_for_each_entry(desc, &nandc->desc_list, node)
> -		cookie = dmaengine_submit(desc->dma_desc);
> -
> -	if (nandc->props->is_bam) {
> -		bam_txn->last_cmd_desc->callback = qpic_bam_dma_done;
> -		bam_txn->last_cmd_desc->callback_param = bam_txn;
> -		if (bam_txn->last_data_desc) {
> -			bam_txn->last_data_desc->callback = qpic_bam_dma_done;
> -			bam_txn->last_data_desc->callback_param = bam_txn;
> -			bam_txn->wait_second_completion = true;
> -		}
> -
> -		dma_async_issue_pending(nandc->tx_chan);
> -		dma_async_issue_pending(nandc->rx_chan);
> -		dma_async_issue_pending(nandc->cmd_chan);
> -
> -		if (!wait_for_completion_timeout(&bam_txn->txn_done,
> -						 QPIC_NAND_COMPLETION_TIMEOUT))
> -			ret = -ETIMEDOUT;
> -	} else {
> -		if (dma_sync_wait(nandc->chan, cookie) != DMA_COMPLETE)
> -			ret = -ETIMEDOUT;
> -	}
> -
> -err_unmap_free_desc:
> -	/*
> -	 * Unmap the dma sg_list and free the desc allocated by both
> -	 * prepare_bam_async_desc() and prep_adm_dma_desc() functions.
> -	 */
> -	list_for_each_entry_safe(desc, n, &nandc->desc_list, node) {
> -		list_del(&desc->node);
> -
> -		if (nandc->props->is_bam)
> -			dma_unmap_sg(nandc->dev, desc->bam_sgl,
> -				     desc->sgl_cnt, desc->dir);
> -		else
> -			dma_unmap_sg(nandc->dev, &desc->adm_sgl, 1,
> -				     desc->dir);
> -
> -		kfree(desc);
> -	}
> -
> -	return ret;
> -}
> -
> -/* reset the register read buffer for next NAND operation */
> -static void clear_read_regs(struct qcom_nand_controller *nandc)
> -{
> -	nandc->reg_read_pos = 0;
> -	nandc_read_buffer_sync(nandc, false);
> -}
> -
>   /*
>    * when using BCH ECC, the HW flags an error in NAND_FLASH_STATUS if it read
>    * an erased CW, and reports an erased CW in NAND_ERASED_CW_DETECT_STATUS.
> @@ -3016,136 +1949,6 @@ static const struct nand_controller_ops qcom_nandc_ops = {
>   	.exec_op = qcom_nand_exec_op,
>   };
>   
> -static void qcom_nandc_unalloc(struct qcom_nand_controller *nandc)
> -{
> -	if (nandc->props->is_bam) {
> -		if (!dma_mapping_error(nandc->dev, nandc->reg_read_dma))
> -			dma_unmap_single(nandc->dev, nandc->reg_read_dma,
> -					 MAX_REG_RD *
> -					 sizeof(*nandc->reg_read_buf),
> -					 DMA_FROM_DEVICE);
> -
> -		if (nandc->tx_chan)
> -			dma_release_channel(nandc->tx_chan);
> -
> -		if (nandc->rx_chan)
> -			dma_release_channel(nandc->rx_chan);
> -
> -		if (nandc->cmd_chan)
> -			dma_release_channel(nandc->cmd_chan);
> -	} else {
> -		if (nandc->chan)
> -			dma_release_channel(nandc->chan);
> -	}
> -}
> -
> -static int qcom_nandc_alloc(struct qcom_nand_controller *nandc)
> -{
> -	int ret;
> -
> -	ret = dma_set_coherent_mask(nandc->dev, DMA_BIT_MASK(32));
> -	if (ret) {
> -		dev_err(nandc->dev, "failed to set DMA mask\n");
> -		return ret;
> -	}
> -
> -	/*
> -	 * we use the internal buffer for reading ONFI params, reading small
> -	 * data like ID and status, and preforming read-copy-write operations
> -	 * when writing to a codeword partially. 532 is the maximum possible
> -	 * size of a codeword for our nand controller
> -	 */
> -	nandc->buf_size = 532;
> -
> -	nandc->data_buffer = devm_kzalloc(nandc->dev, nandc->buf_size, GFP_KERNEL);
> -	if (!nandc->data_buffer)
> -		return -ENOMEM;
> -
> -	nandc->regs = devm_kzalloc(nandc->dev, sizeof(*nandc->regs), GFP_KERNEL);
> -	if (!nandc->regs)
> -		return -ENOMEM;
> -
> -	nandc->reg_read_buf = devm_kcalloc(nandc->dev, MAX_REG_RD,
> -					   sizeof(*nandc->reg_read_buf),
> -					   GFP_KERNEL);
> -	if (!nandc->reg_read_buf)
> -		return -ENOMEM;
> -
> -	if (nandc->props->is_bam) {
> -		nandc->reg_read_dma =
> -			dma_map_single(nandc->dev, nandc->reg_read_buf,
> -				       MAX_REG_RD *
> -				       sizeof(*nandc->reg_read_buf),
> -				       DMA_FROM_DEVICE);
> -		if (dma_mapping_error(nandc->dev, nandc->reg_read_dma)) {
> -			dev_err(nandc->dev, "failed to DMA MAP reg buffer\n");
> -			return -EIO;
> -		}
> -
> -		nandc->tx_chan = dma_request_chan(nandc->dev, "tx");
> -		if (IS_ERR(nandc->tx_chan)) {
> -			ret = PTR_ERR(nandc->tx_chan);
> -			nandc->tx_chan = NULL;
> -			dev_err_probe(nandc->dev, ret,
> -				      "tx DMA channel request failed\n");
> -			goto unalloc;
> -		}
> -
> -		nandc->rx_chan = dma_request_chan(nandc->dev, "rx");
> -		if (IS_ERR(nandc->rx_chan)) {
> -			ret = PTR_ERR(nandc->rx_chan);
> -			nandc->rx_chan = NULL;
> -			dev_err_probe(nandc->dev, ret,
> -				      "rx DMA channel request failed\n");
> -			goto unalloc;
> -		}
> -
> -		nandc->cmd_chan = dma_request_chan(nandc->dev, "cmd");
> -		if (IS_ERR(nandc->cmd_chan)) {
> -			ret = PTR_ERR(nandc->cmd_chan);
> -			nandc->cmd_chan = NULL;
> -			dev_err_probe(nandc->dev, ret,
> -				      "cmd DMA channel request failed\n");
> -			goto unalloc;
> -		}
> -
> -		/*
> -		 * Initially allocate BAM transaction to read ONFI param page.
> -		 * After detecting all the devices, this BAM transaction will
> -		 * be freed and the next BAM transaction will be allocated with
> -		 * maximum codeword size
> -		 */
> -		nandc->max_cwperpage = 1;
> -		nandc->bam_txn = alloc_bam_transaction(nandc);
> -		if (!nandc->bam_txn) {
> -			dev_err(nandc->dev,
> -				"failed to allocate bam transaction\n");
> -			ret = -ENOMEM;
> -			goto unalloc;
> -		}
> -	} else {
> -		nandc->chan = dma_request_chan(nandc->dev, "rxtx");
> -		if (IS_ERR(nandc->chan)) {
> -			ret = PTR_ERR(nandc->chan);
> -			nandc->chan = NULL;
> -			dev_err_probe(nandc->dev, ret,
> -				      "rxtx DMA channel request failed\n");
> -			return ret;
> -		}
> -	}
> -
> -	INIT_LIST_HEAD(&nandc->desc_list);
> -	INIT_LIST_HEAD(&nandc->host_list);
> -
> -	nand_controller_init(&nandc->controller);
> -	nandc->controller.ops = &qcom_nandc_ops;
> -
> -	return 0;
> -unalloc:
> -	qcom_nandc_unalloc(nandc);
> -	return ret;
> -}
> -
>   /* one time setup of a few nand controller registers */
>   static int qcom_nandc_setup(struct qcom_nand_controller *nandc)
>   {
> @@ -3427,6 +2230,9 @@ static int qcom_nandc_probe(struct platform_device *pdev)
>   	if (ret)
>   		goto err_nandc_alloc;
>   
> +	nand_controller_init(&nandc->controller);
> +	nandc->controller.ops = &qcom_nandc_ops;
> +
>   	ret = qcom_nandc_setup(nandc);
>   	if (ret)
>   		goto err_setup;
> @@ -3473,28 +2279,28 @@ static void qcom_nandc_remove(struct platform_device *pdev)
>   			   DMA_BIDIRECTIONAL, 0);
>   }
>   
> -static const struct qcom_nandc_props ipq806x_nandc_props = {
> +static struct qcom_nandc_props ipq806x_nandc_props = {
>   	.ecc_modes = (ECC_RS_4BIT | ECC_BCH_8BIT),
>   	.is_bam = false,
>   	.use_codeword_fixup = true,
>   	.dev_cmd_reg_start = 0x0,
>   };
>   
> -static const struct qcom_nandc_props ipq4019_nandc_props = {
> +static struct qcom_nandc_props ipq4019_nandc_props = {
>   	.ecc_modes = (ECC_BCH_4BIT | ECC_BCH_8BIT),
>   	.is_bam = true,
>   	.is_qpic = true,
>   	.dev_cmd_reg_start = 0x0,
>   };
>   
> -static const struct qcom_nandc_props ipq8074_nandc_props = {
> +static struct qcom_nandc_props ipq8074_nandc_props = {
>   	.ecc_modes = (ECC_BCH_4BIT | ECC_BCH_8BIT),
>   	.is_bam = true,
>   	.is_qpic = true,
>   	.dev_cmd_reg_start = 0x7000,
>   };
>   
> -static const struct qcom_nandc_props sdx55_nandc_props = {
> +static struct qcom_nandc_props sdx55_nandc_props = {
>   	.ecc_modes = (ECC_BCH_4BIT | ECC_BCH_8BIT),
>   	.is_bam = true,
>   	.is_qpic = true,
> diff --git a/include/linux/mtd/nand-qpic-common.h b/include/linux/mtd/nand-qpic-common.h
> new file mode 100644
> index 000000000000..891f975ca173
> --- /dev/null
> +++ b/include/linux/mtd/nand-qpic-common.h
> @@ -0,0 +1,488 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * QCOM QPIC common APIs header file
> + *
> + * Copyright (c) 2023 Qualcomm Inc.
> + * Authors:     Md sadre Alam           <quic_mdalam@quicinc.com>
> + *		Sricharan R             <quic_srichara@quicinc.com>
> + *		Varadarajan Narayanan   <quic_varada@quicinc.com>
> + *
> + */
> +#ifndef __MTD_NAND_QPIC_COMMON_H__
> +#define __MTD_NAND_QPIC_COMMON_H__
> +
> +#include <linux/bitops.h>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/dmaengine.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/dma/qcom_adm.h>
> +#include <linux/dma/qcom_bam_dma.h>
> +#include <linux/module.h>
> +#include <linux/mtd/partitions.h>
> +#include <linux/mtd/rawnand.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +
> +/* NANDc reg offsets */
> +#define	NAND_FLASH_CMD			0x00
> +#define	NAND_ADDR0			0x04
> +#define	NAND_ADDR1			0x08
> +#define	NAND_FLASH_CHIP_SELECT		0x0c
> +#define	NAND_EXEC_CMD			0x10
> +#define	NAND_FLASH_STATUS		0x14
> +#define	NAND_BUFFER_STATUS		0x18
> +#define	NAND_DEV0_CFG0			0x20
> +#define	NAND_DEV0_CFG1			0x24
> +#define	NAND_DEV0_ECC_CFG		0x28
> +#define	NAND_AUTO_STATUS_EN		0x2c
> +#define	NAND_DEV1_CFG0			0x30
> +#define	NAND_DEV1_CFG1			0x34
> +#define	NAND_READ_ID			0x40
> +#define	NAND_READ_STATUS		0x44
> +#define	NAND_DEV_CMD0			0xa0
> +#define	NAND_DEV_CMD1			0xa4
> +#define	NAND_DEV_CMD2			0xa8
> +#define	NAND_DEV_CMD_VLD		0xac
> +#define	SFLASHC_BURST_CFG		0xe0
> +#define	NAND_ERASED_CW_DETECT_CFG	0xe8
> +#define	NAND_ERASED_CW_DETECT_STATUS	0xec
> +#define	NAND_EBI2_ECC_BUF_CFG		0xf0
> +#define	FLASH_BUF_ACC			0x100
> +
> +#define	NAND_CTRL			0xf00
> +#define	NAND_VERSION			0xf08
> +#define	NAND_READ_LOCATION_0		0xf20
> +#define	NAND_READ_LOCATION_1		0xf24
> +#define	NAND_READ_LOCATION_2		0xf28
> +#define	NAND_READ_LOCATION_3		0xf2c
> +#define	NAND_READ_LOCATION_LAST_CW_0	0xf40
> +#define	NAND_READ_LOCATION_LAST_CW_1	0xf44
> +#define	NAND_READ_LOCATION_LAST_CW_2	0xf48
> +#define	NAND_READ_LOCATION_LAST_CW_3	0xf4c
> +
> +/* dummy register offsets, used by write_reg_dma */
> +#define	NAND_DEV_CMD1_RESTORE		0xdead
> +#define	NAND_DEV_CMD_VLD_RESTORE	0xbeef
> +
> +/* NAND_FLASH_CMD bits */
> +#define	PAGE_ACC			BIT(4)
> +#define	LAST_PAGE			BIT(5)
> +
> +/* NAND_FLASH_CHIP_SELECT bits */
> +#define	NAND_DEV_SEL			0
> +#define	DM_EN				BIT(2)
> +
> +/* NAND_FLASH_STATUS bits */
> +#define	FS_OP_ERR			BIT(4)
> +#define	FS_READY_BSY_N			BIT(5)
> +#define	FS_MPU_ERR			BIT(8)
> +#define	FS_DEVICE_STS_ERR		BIT(16)
> +#define	FS_DEVICE_WP			BIT(23)
> +
> +/* NAND_BUFFER_STATUS bits */
> +#define	BS_UNCORRECTABLE_BIT		BIT(8)
> +#define	BS_CORRECTABLE_ERR_MSK		0x1f
> +
> +/* NAND_DEVn_CFG0 bits */
> +#define	DISABLE_STATUS_AFTER_WRITE	4
> +#define	CW_PER_PAGE			6
> +#define	UD_SIZE_BYTES			9
> +#define	UD_SIZE_BYTES_MASK		GENMASK(18, 9)
> +#define	ECC_PARITY_SIZE_BYTES_RS	19
> +#define	SPARE_SIZE_BYTES		23
> +#define	SPARE_SIZE_BYTES_MASK		GENMASK(26, 23)
> +#define	NUM_ADDR_CYCLES			27
> +#define	STATUS_BFR_READ			30
> +#define	SET_RD_MODE_AFTER_STATUS	31
> +
> +/* NAND_DEVn_CFG0 bits */
> +#define	DEV0_CFG1_ECC_DISABLE		0
> +#define	WIDE_FLASH			1
> +#define	NAND_RECOVERY_CYCLES		2
> +#define	CS_ACTIVE_BSY			5
> +#define	BAD_BLOCK_BYTE_NUM		6
> +#define	BAD_BLOCK_IN_SPARE_AREA		16
> +#define	WR_RD_BSY_GAP			17
> +#define	ENABLE_BCH_ECC			27
> +
> +/* NAND_DEV0_ECC_CFG bits */
> +#define	ECC_CFG_ECC_DISABLE		0
> +#define	ECC_SW_RESET			1
> +#define	ECC_MODE			4
> +#define	ECC_PARITY_SIZE_BYTES_BCH	8
> +#define	ECC_NUM_DATA_BYTES		16
> +#define	ECC_NUM_DATA_BYTES_MASK		GENMASK(25, 16)
> +#define	ECC_FORCE_CLK_OPEN		30
> +
> +/* NAND_DEV_CMD1 bits */
> +#define	READ_ADDR			0
> +
> +/* NAND_DEV_CMD_VLD bits */
> +#define	READ_START_VLD			BIT(0)
> +#define	READ_STOP_VLD			BIT(1)
> +#define	WRITE_START_VLD			BIT(2)
> +#define	ERASE_START_VLD			BIT(3)
> +#define	SEQ_READ_START_VLD		BIT(4)
> +
> +/* NAND_EBI2_ECC_BUF_CFG bits */
> +#define	NUM_STEPS			0
> +
> +/* NAND_ERASED_CW_DETECT_CFG bits */
> +#define	ERASED_CW_ECC_MASK		1
> +#define	AUTO_DETECT_RES			0
> +#define	MASK_ECC			BIT(ERASED_CW_ECC_MASK)
> +#define	RESET_ERASED_DET		BIT(AUTO_DETECT_RES)
> +#define	ACTIVE_ERASED_DET		(0 << AUTO_DETECT_RES)
> +#define	CLR_ERASED_PAGE_DET		(RESET_ERASED_DET | MASK_ECC)
> +#define	SET_ERASED_PAGE_DET		(ACTIVE_ERASED_DET | MASK_ECC)
> +
> +/* NAND_ERASED_CW_DETECT_STATUS bits */
> +#define	PAGE_ALL_ERASED			BIT(7)
> +#define	CODEWORD_ALL_ERASED		BIT(6)
> +#define	PAGE_ERASED			BIT(5)
> +#define	CODEWORD_ERASED			BIT(4)
> +#define	ERASED_PAGE			(PAGE_ALL_ERASED | PAGE_ERASED)
> +#define	ERASED_CW			(CODEWORD_ALL_ERASED | CODEWORD_ERASED)
> +
> +/* NAND_READ_LOCATION_n bits */
> +#define READ_LOCATION_OFFSET		0
> +#define READ_LOCATION_SIZE		16
> +#define READ_LOCATION_LAST		31
> +
> +/* Version Mask */
> +#define	NAND_VERSION_MAJOR_MASK		0xf0000000
> +#define	NAND_VERSION_MAJOR_SHIFT	28
> +#define	NAND_VERSION_MINOR_MASK		0x0fff0000
> +#define	NAND_VERSION_MINOR_SHIFT	16
> +
> +/* NAND OP_CMDs */
> +#define	OP_PAGE_READ			0x2
> +#define	OP_PAGE_READ_WITH_ECC		0x3
> +#define	OP_PAGE_READ_WITH_ECC_SPARE	0x4
> +#define	OP_PAGE_READ_ONFI_READ		0x5
> +#define	OP_PROGRAM_PAGE			0x6
> +#define	OP_PAGE_PROGRAM_WITH_ECC	0x7
> +#define	OP_PROGRAM_PAGE_SPARE		0x9
> +#define	OP_BLOCK_ERASE			0xa
> +#define	OP_CHECK_STATUS			0xc
> +#define	OP_FETCH_ID			0xb
> +#define	OP_RESET_DEVICE			0xd
> +
> +/* Default Value for NAND_DEV_CMD_VLD */
> +#define NAND_DEV_CMD_VLD_VAL		(READ_START_VLD | WRITE_START_VLD | \
> +					 ERASE_START_VLD | SEQ_READ_START_VLD)
> +
> +/* NAND_CTRL bits */
> +#define	BAM_MODE_EN			BIT(0)
> +
> +/*
> + * the NAND controller performs reads/writes with ECC in 516 byte chunks.
> + * the driver calls the chunks 'step' or 'codeword' interchangeably
> + */
> +#define	NANDC_STEP_SIZE			512
> +
> +/*
> + * the largest page size we support is 8K, this will have 16 steps/codewords
> + * of 512 bytes each
> + */
> +#define	MAX_NUM_STEPS			(SZ_8K / NANDC_STEP_SIZE)
> +
> +/* we read at most 3 registers per codeword scan */
> +#define	MAX_REG_RD			(3 * MAX_NUM_STEPS)
> +
> +#define QPIC_PER_CW_CMD_ELEMENTS	32
> +#define QPIC_PER_CW_CMD_SGL		32
> +#define QPIC_PER_CW_DATA_SGL		8
> +
> +#define QPIC_NAND_COMPLETION_TIMEOUT	msecs_to_jiffies(2000)
> +
> +/*
> + * Flags used in DMA descriptor preparation helper functions
> + * (i.e. read_reg_dma/write_reg_dma/read_data_dma/write_data_dma)
> + */
> +/* Don't set the EOT in current tx BAM sgl */
> +#define NAND_BAM_NO_EOT			BIT(0)
> +/* Set the NWD flag in current BAM sgl */
> +#define NAND_BAM_NWD			BIT(1)
> +/* Finish writing in the current BAM sgl and start writing in another BAM sgl */
> +#define NAND_BAM_NEXT_SGL		BIT(2)
> +
> +/*
> + * Returns the actual register address for all NAND_DEV_ registers
> + * (i.e. NAND_DEV_CMD0, NAND_DEV_CMD1, NAND_DEV_CMD2 and NAND_DEV_CMD_VLD)
> + */
> +#define dev_cmd_reg_addr(nandc, reg) ((nandc)->props->dev_cmd_reg_start + (reg))
> +
> +/* Returns the NAND register physical address */
> +#define nandc_reg_phys(chip, offset) ((chip)->base_phys + (offset))
> +
> +/* Returns the dma address for reg read buffer */
> +#define reg_buf_dma_addr(chip, vaddr) \
> +	((chip)->reg_read_dma + \
> +	((u8 *)(vaddr) - (u8 *)(chip)->reg_read_buf))
> +
> +/*
> + * Erased codeword status is being used two times in single transfer so this
> + * flag will determine the current value of erased codeword status register
> + */
> +#define NAND_ERASED_CW_SET		BIT(4)
> +
> +#define MAX_ADDRESS_CYCLE		5
> +
> +/*
> + * This data type corresponds to the BAM transaction which will be used for all
> + * NAND transfers.
> + * @bam_ce - the array of BAM command elements
> + * @cmd_sgl - sgl for NAND BAM command pipe
> + * @data_sgl - sgl for NAND BAM consumer/producer pipe
> + * @last_data_desc - last DMA desc in data channel (tx/rx).
> + * @last_cmd_desc - last DMA desc in command channel.
> + * @txn_done - completion for NAND transfer.
> + * @bam_ce_pos - the index in bam_ce which is available for next sgl
> + * @bam_ce_start - the index in bam_ce which marks the start position ce
> + *		   for current sgl. It will be used for size calculation
> + *		   for current sgl
> + * @cmd_sgl_pos - current index in command sgl.
> + * @cmd_sgl_start - start index in command sgl.
> + * @tx_sgl_pos - current index in data sgl for tx.
> + * @tx_sgl_start - start index in data sgl for tx.
> + * @rx_sgl_pos - current index in data sgl for rx.
> + * @rx_sgl_start - start index in data sgl for rx.
> + * @wait_second_completion - wait for second DMA desc completion before making
> + *			     the NAND transfer completion.
> + */
> +struct bam_transaction {
> +	struct bam_cmd_element *bam_ce;
> +	struct scatterlist *cmd_sgl;
> +	struct scatterlist *data_sgl;
> +	struct dma_async_tx_descriptor *last_data_desc;
> +	struct dma_async_tx_descriptor *last_cmd_desc;
> +	struct completion txn_done;
> +	u32 bam_ce_pos;
> +	u32 bam_ce_start;
> +	u32 cmd_sgl_pos;
> +	u32 cmd_sgl_start;
> +	u32 tx_sgl_pos;
> +	u32 tx_sgl_start;
> +	u32 rx_sgl_pos;
> +	u32 rx_sgl_start;
> +	bool wait_second_completion;
> +};
> +
> +/*
> + * This data type corresponds to the nand dma descriptor
> + * @dma_desc - low level DMA engine descriptor
> + * @list - list for desc_info
> + *
> + * @adm_sgl - sgl which will be used for single sgl dma descriptor. Only used by
> + *	      ADM
> + * @bam_sgl - sgl which will be used for dma descriptor. Only used by BAM
> + * @sgl_cnt - number of SGL in bam_sgl. Only used by BAM
> + * @dir - DMA transfer direction
> + */
> +struct desc_info {
> +	struct dma_async_tx_descriptor *dma_desc;
> +	struct list_head node;
> +
> +	union {
> +		struct scatterlist adm_sgl;
> +		struct {
> +			struct scatterlist *bam_sgl;
> +			int sgl_cnt;
> +		};
> +	};
> +	enum dma_data_direction dir;
> +};
> +
> +/*
> + * holds the current register values that we want to write. acts as a contiguous
> + * chunk of memory which we use to write the controller registers through DMA.
> + */
> +struct nandc_regs {
> +	__le32 cmd;
> +	__le32 addr0;
> +	__le32 addr1;
> +	__le32 chip_sel;
> +	__le32 exec;
> +
> +	__le32 cfg0;
> +	__le32 cfg1;
> +	__le32 ecc_bch_cfg;
> +
> +	__le32 clrflashstatus;
> +	__le32 clrreadstatus;
> +
> +	__le32 cmd1;
> +	__le32 vld;
> +
> +	__le32 orig_cmd1;
> +	__le32 orig_vld;
> +
> +	__le32 ecc_buf_cfg;
> +	__le32 read_location0;
> +	__le32 read_location1;
> +	__le32 read_location2;
> +	__le32 read_location3;
> +	__le32 read_location_last0;
> +	__le32 read_location_last1;
> +	__le32 read_location_last2;
> +	__le32 read_location_last3;
> +
> +	__le32 erased_cw_detect_cfg_clr;
> +	__le32 erased_cw_detect_cfg_set;
> +};
> +
> +/*
> + * NAND controller data struct
> + *
> + * @dev:			parent device
> + *
> + * @base:			MMIO base
> + *
> + * @core_clk:			controller clock
> + * @aon_clk:			another controller clock
> + *
> + * @regs:			a contiguous chunk of memory for DMA register
> + *				writes. contains the register values to be
> + *				written to controller
> + *
> + * @props:			properties of current NAND controller,
> + *				initialized via DT match data
> + *
> + * @controller:			base controller structure
> + * @host_list:			list containing all the chips attached to the
> + *				controller
> + *
> + * @chan:			dma channel
> + * @cmd_crci:			ADM DMA CRCI for command flow control
> + * @data_crci:			ADM DMA CRCI for data flow control
> + *
> + * @desc_list:			DMA descriptor list (list of desc_infos)
> + *
> + * @data_buffer:		our local DMA buffer for page read/writes,
> + *				used when we can't use the buffer provided
> + *				by upper layers directly
> + * @reg_read_buf:		local buffer for reading back registers via DMA
> + *
> + * @base_phys:			physical base address of controller registers
> + * @base_dma:			dma base address of controller registers
> + * @reg_read_dma:		contains dma address for register read buffer
> + *
> + * @buf_size/count/start:	markers for chip->legacy.read_buf/write_buf
> + *				functions
> + * @max_cwperpage:		maximum QPIC codewords required. calculated
> + *				from all connected NAND devices pagesize
> + *
> + * @reg_read_pos:		marker for data read in reg_read_buf
> + *
> + * @cmd1/vld:			some fixed controller register values
> + *
> + * @exec_opwrite:		flag to select correct number of code word
> + *				while reading status
> + */
> +struct qcom_nand_controller {
> +	struct device *dev;
> +
> +	void __iomem *base;
> +
> +	struct clk *core_clk;
> +	struct clk *aon_clk;
> +
> +	struct nandc_regs *regs;
> +	struct bam_transaction *bam_txn;
> +
> +	const struct qcom_nandc_props *props;
> +
> +	struct nand_controller controller;
> +	struct list_head host_list;
> +
> +	union {
> +		/* will be used only by QPIC for BAM DMA */
> +		struct {
> +			struct dma_chan *tx_chan;
> +			struct dma_chan *rx_chan;
> +			struct dma_chan *cmd_chan;
> +		};
> +
> +		/* will be used only by EBI2 for ADM DMA */
> +		struct {
> +			struct dma_chan *chan;
> +			unsigned int cmd_crci;
> +			unsigned int data_crci;
> +		};
> +	};
> +
> +	struct list_head desc_list;
> +
> +	u8		*data_buffer;
> +	__le32		*reg_read_buf;
> +
> +	phys_addr_t base_phys;
> +	dma_addr_t base_dma;
> +	dma_addr_t reg_read_dma;
> +
> +	int		buf_size;
> +	int		buf_count;
> +	int		buf_start;
> +	unsigned int	max_cwperpage;
> +
> +	int reg_read_pos;
> +
> +	u32 cmd1, vld;
> +	bool exec_opwrite;
> +};
> +
> +/*
> + * This data type corresponds to the NAND controller properties which varies
> + * among different NAND controllers.
> + * @ecc_modes - ecc mode for NAND
> + * @dev_cmd_reg_start - NAND_DEV_CMD_* registers starting offset
> + * @is_bam - whether NAND controller is using BAM
> + * @is_qpic - whether NAND CTRL is part of qpic IP
> + * @qpic_v2 - flag to indicate QPIC IP version 2
> + * @use_codeword_fixup - whether NAND has different layout for boot partitions
> + */
> +struct qcom_nandc_props {
> +	u32 ecc_modes;
> +	u32 dev_cmd_reg_start;
> +	bool is_bam;
> +	bool is_qpic;
> +	bool qpic_v2;
> +	bool use_codeword_fixup;
> +};
> +
> +void config_nand_page_read(struct nand_chip *chip);
> +void free_bam_transaction(struct qcom_nand_controller *nandc);
> +void qpic_bam_dma_done(void *data);
> +void nandc_read_buffer_sync(struct qcom_nand_controller *nandc, bool is_cpu);
> +__le32 *offset_to_nandc_reg(struct nandc_regs *regs, int offset);
> +void clear_read_regs(struct qcom_nand_controller *nandc);
> +int prep_adm_dma_desc(struct qcom_nand_controller *nandc, bool read,
> +		      int reg_off, const void *vaddr, int size,
> +			bool flow_control);
> +int submit_descs(struct qcom_nand_controller *nandc);
> +int prepare_bam_async_desc(struct qcom_nand_controller *nandc,
> +			   struct dma_chan *chan, unsigned long flags);
> +int prep_bam_dma_desc_cmd(struct qcom_nand_controller *nandc, bool read,
> +			  int reg_off, const void *vaddr,
> +			int size, unsigned int flags);
> +int prep_bam_dma_desc_data(struct qcom_nand_controller *nandc, bool read,
> +			   const void *vaddr,
> +			int size, unsigned int flags);
> +int read_reg_dma(struct qcom_nand_controller *nandc, int first,
> +		 int num_regs, unsigned int flags);
> +int write_reg_dma(struct qcom_nand_controller *nandc, int first,
> +		  int num_regs, unsigned int flags);
> +int read_data_dma(struct qcom_nand_controller *nandc, int reg_off,
> +		  const u8 *vaddr, int size, unsigned int flags);
> +int write_data_dma(struct qcom_nand_controller *nandc, int reg_off,
> +		   const u8 *vaddr, int size, unsigned int flags);
> +struct bam_transaction *alloc_bam_transaction(struct qcom_nand_controller *nandc);
> +void clear_bam_transaction(struct qcom_nand_controller *nandc);
> +void qcom_nandc_unalloc(struct qcom_nand_controller *nandc);
> +int qcom_nandc_alloc(struct qcom_nand_controller *nandc);
> +struct qcom_nand_controller *get_qcom_nand_controller(struct nand_chip *chip);
> +
> +#endif

On 2/15/2024 11:25 PM, Konrad Dybcio wrote:
> On 15.02.2024 14:48, Md Sadre Alam wrote:
>> Add qpic_common.c file which hold all the common
>> qpic APIs which will be used by both qpic raw nand
>> driver and qpic spi nand driver.
>>
>> Co-developed-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
>> Signed-off-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
>> Co-developed-by: Varadarajan Narayanan <quic_varada@quicinc.com>
>> Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
>> Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
>> ---
> 
> IIUC this is mostly moving code around?
> 
> I do however have some suggestions..
Ok
> 
>>   drivers/mtd/nand/Makefile            |    1 +
>>   drivers/mtd/nand/qpic_common.c       |  786 +++++++++++++++++
>>   drivers/mtd/nand/raw/qcom_nandc.c    | 1226 +-------------------------
>>   include/linux/mtd/nand-qpic-common.h |  488 ++++++++++
>>   4 files changed, 1291 insertions(+), 1210 deletions(-)
>>   create mode 100644 drivers/mtd/nand/qpic_common.c
>>   create mode 100644 include/linux/mtd/nand-qpic-common.h
>>
>> diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
>> index 19e1291ac4d5..131707a41293 100644
>> --- a/drivers/mtd/nand/Makefile
>> +++ b/drivers/mtd/nand/Makefile
>> @@ -12,3 +12,4 @@ nandcore-$(CONFIG_MTD_NAND_ECC) += ecc.o
>>   nandcore-$(CONFIG_MTD_NAND_ECC_SW_HAMMING) += ecc-sw-hamming.o
>>   nandcore-$(CONFIG_MTD_NAND_ECC_SW_BCH) += ecc-sw-bch.o
>>   nandcore-$(CONFIG_MTD_NAND_ECC_MXIC) += ecc-mxic.o
>> +obj-y += qpic_common.o
>> diff --git a/drivers/mtd/nand/qpic_common.c b/drivers/mtd/nand/qpic_common.c
>> new file mode 100644
>> index 000000000000..4d74ba888028
>> --- /dev/null
>> +++ b/drivers/mtd/nand/qpic_common.c
>> @@ -0,0 +1,786 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * QPIC Controller common API file.
>> + * Copyright (C) 2023  Qualcomm Inc.
>> + * Authors:	Md sadre Alam           <quic_mdalam@quicinc.com>
>> + *		Sricharan R             <quic_srichara@quicinc.com>
>> + *		Varadarajan Narayanan	<quic_varada@quicinc.com>
>> + *
>> + */
>> +
>> +#include <linux/mtd/nand-qpic-common.h>
>> +
>> +struct qcom_nand_controller *
>> +get_qcom_nand_controller(struct nand_chip *chip)
>> +{
>> +	return container_of(chip->controller, struct qcom_nand_controller,
>> +			    controller);
>> +}
>> +EXPORT_SYMBOL(get_qcom_nand_controller);
> 
> #define to_qcom_nand_controller()?
Ok
> 
>> +
>> +/*
>> + * Helper to prepare DMA descriptors for configuring registers
>> + * before reading a NAND page.
>> + */
> 
> Can you convert these to kerneldoc instead?
Ok
> 
>> +void config_nand_page_read(struct nand_chip *chip)
>> +{
>> +	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
>> +
>> +	write_reg_dma(nandc, NAND_ADDR0, 2, 0);
>> +	write_reg_dma(nandc, NAND_DEV0_CFG0, 3, 0);
>> +	if (!nandc->props->qpic_v2)
> 
> This is not going to scale going forward.. please include a version
> enum instead.
Ok
> 
> [...]
> 
>> +
>> +int prep_adm_dma_desc(struct qcom_nand_controller *nandc, bool read,
>> +		      int reg_off, const void *vaddr, int size,
>> +			     bool flow_control)
>> +{
>> +	struct desc_info *desc;
>> +	struct dma_async_tx_descriptor *dma_desc;
>> +	struct scatterlist *sgl;
>> +	struct dma_slave_config slave_conf;
>> +	struct qcom_adm_peripheral_config periph_conf = {};
>> +	enum dma_transfer_direction dir_eng;
>> +	int ret;
> 
> Revertse-christmas-tree, please
Ok
> 
>> +
>> +	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
>> +	if (!desc)
>> +		return -ENOMEM;
>> +
>> +	sgl = &desc->adm_sgl;
>> +
>> +	sg_init_one(sgl, vaddr, size);
>> +
>> +	if (read) {
>> +		dir_eng = DMA_DEV_TO_MEM;
>> +		desc->dir = DMA_FROM_DEVICE;
>> +	} else {
>> +		dir_eng = DMA_MEM_TO_DEV;
>> +		desc->dir = DMA_TO_DEVICE;
>> +	}
>> +
>> +	ret = dma_map_sg(nandc->dev, sgl, 1, desc->dir);
>> +	if (ret == 0) {
> 
> if (!ret)
Ok
> 
>> +		ret = -ENOMEM;
>> +		goto err;
>> +	}
>> +
>> +	memset(&slave_conf, 0x00, sizeof(slave_conf));
> 
> Just zero-initialize it (= { 0 }) at declaration time
Ok
> 
> Konrad
> 

Thanks for reviewing , I will fix all the comments in next patch.

Regards,
Alam.

On 2/16/2024 8:59 PM, Kathiravan Thirumoorthy wrote:
> 
> 
> On 2/15/2024 7:18 PM, Md Sadre Alam wrote:
>> Add qpic_common.c file which hold all the common
>> qpic APIs which will be used by both qpic raw nand
>> driver and qpic spi nand driver.
>>
>> Co-developed-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
>> Signed-off-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
>> Co-developed-by: Varadarajan Narayanan <quic_varada@quicinc.com>
>> Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
>> Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
>> ---
>>   drivers/mtd/nand/Makefile            |    1 +
>>   drivers/mtd/nand/qpic_common.c       |  786 +++++++++++++++++
>>   drivers/mtd/nand/raw/qcom_nandc.c    | 1226 +-------------------------
>>   include/linux/mtd/nand-qpic-common.h |  488 ++++++++++
>>   4 files changed, 1291 insertions(+), 1210 deletions(-)
>>   create mode 100644 drivers/mtd/nand/qpic_common.c
>>   create mode 100644 include/linux/mtd/nand-qpic-common.h
>>
>> diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
>> index 19e1291ac4d5..131707a41293 100644
>> --- a/drivers/mtd/nand/Makefile
>> +++ b/drivers/mtd/nand/Makefile
>> @@ -12,3 +12,4 @@ nandcore-$(CONFIG_MTD_NAND_ECC) += ecc.o
>>   nandcore-$(CONFIG_MTD_NAND_ECC_SW_HAMMING) += ecc-sw-hamming.o
>>   nandcore-$(CONFIG_MTD_NAND_ECC_SW_BCH) += ecc-sw-bch.o
>>   nandcore-$(CONFIG_MTD_NAND_ECC_MXIC) += ecc-mxic.o
>> +obj-y += qpic_common.o
>> diff --git a/drivers/mtd/nand/qpic_common.c b/drivers/mtd/nand/qpic_common.c
>> new file mode 100644
>> index 000000000000..4d74ba888028
>> --- /dev/null
>> +++ b/drivers/mtd/nand/qpic_common.c
>> @@ -0,0 +1,786 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * QPIC Controller common API file.
>> + * Copyright (C) 2023  Qualcomm Inc.
> 
> 
> Copyright should be repharsed?

  Will fix in next patch.

> 
>> + * Authors:    Md sadre Alam           <quic_mdalam@quicinc.com>
>> + *        Sricharan R             <quic_srichara@quicinc.com>
>> + *        Varadarajan Narayanan    <quic_varada@quicinc.com>
>> + *
>> + */
>> +
>> +#include <linux/mtd/nand-qpic-common.h>
>> +
>> +struct qcom_nand_controller *
>> +get_qcom_nand_controller(struct nand_chip *chip)
>> +{
>> +    return container_of(chip->controller, struct qcom_nand_controller,
>> +                controller);
>> +}
>> +EXPORT_SYMBOL(get_qcom_nand_controller);
>> +
>> +/*
>> + * Helper to prepare DMA descriptors for configuring registers
>> + * before reading a NAND page.
>> + */
>> +void config_nand_page_read(struct nand_chip *chip)
>> +{
>> +    struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
>> +
>> +    write_reg_dma(nandc, NAND_ADDR0, 2, 0);
>> +    write_reg_dma(nandc, NAND_DEV0_CFG0, 3, 0);
>> +    if (!nandc->props->qpic_v2)
>> +        write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1, 0);
>> +    write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1, 0);
>> +    write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1,
>> +              NAND_ERASED_CW_SET | NAND_BAM_NEXT_SGL);
>> +}
>> +EXPORT_SYMBOL(config_nand_page_read);
>> +
>> +/* Frees the BAM transaction memory */
>> +void free_bam_transaction(struct qcom_nand_controller *nandc)
>> +{
>> +    struct bam_transaction *bam_txn = nandc->bam_txn;
>> +
>> +    devm_kfree(nandc->dev, bam_txn);
>> +}
>> +EXPORT_SYMBOL(free_bam_transaction);
>> +
>> +/* Callback for DMA descriptor completion */
>> +void qpic_bam_dma_done(void *data)
>> +{
>> +    struct bam_transaction *bam_txn = data;
>> +
>> +    /*
>> +     * In case of data transfer with NAND, 2 callbacks will be generated.
>> +     * One for command channel and another one for data channel.
>> +     * If current transaction has data descriptors
>> +     * (i.e. wait_second_completion is true), then set this to false
>> +     * and wait for second DMA descriptor completion.
>> +     */
>> +    if (bam_txn->wait_second_completion)
>> +        bam_txn->wait_second_completion = false;
>> +    else
>> +        complete(&bam_txn->txn_done);
>> +}
>> +EXPORT_SYMBOL(qpic_bam_dma_done);
>> +
>> +void nandc_read_buffer_sync(struct qcom_nand_controller *nandc,
>> +                bool is_cpu)
>> +{
>> +    if (!nandc->props->is_bam)
>> +        return;
>> +
>> +    if (is_cpu)
>> +        dma_sync_single_for_cpu(nandc->dev, nandc->reg_read_dma,
>> +                    MAX_REG_RD *
>> +                    sizeof(*nandc->reg_read_buf),
>> +                    DMA_FROM_DEVICE);
>> +    else
>> +        dma_sync_single_for_device(nandc->dev, nandc->reg_read_dma,
>> +                       MAX_REG_RD *
>> +                       sizeof(*nandc->reg_read_buf),
>> +                       DMA_FROM_DEVICE);
>> +}
>> +EXPORT_SYMBOL(nandc_read_buffer_sync);
>> +
>> +__le32 *offset_to_nandc_reg(struct nandc_regs *regs, int offset)
>> +{
>> +    switch (offset) {
>> +    case NAND_FLASH_CMD:
>> +        return &regs->cmd;
>> +    case NAND_ADDR0:
>> +        return &regs->addr0;
>> +    case NAND_ADDR1:
>> +        return &regs->addr1;
>> +    case NAND_FLASH_CHIP_SELECT:
>> +        return &regs->chip_sel;
>> +    case NAND_EXEC_CMD:
>> +        return &regs->exec;
>> +    case NAND_FLASH_STATUS:
>> +        return &regs->clrflashstatus;
>> +    case NAND_DEV0_CFG0:
>> +        return &regs->cfg0;
>> +    case NAND_DEV0_CFG1:
>> +        return &regs->cfg1;
>> +    case NAND_DEV0_ECC_CFG:
>> +        return &regs->ecc_bch_cfg;
>> +    case NAND_READ_STATUS:
>> +        return &regs->clrreadstatus;
>> +    case NAND_DEV_CMD1:
>> +        return &regs->cmd1;
>> +    case NAND_DEV_CMD1_RESTORE:
>> +        return &regs->orig_cmd1;
>> +    case NAND_DEV_CMD_VLD:
>> +        return &regs->vld;
>> +    case NAND_DEV_CMD_VLD_RESTORE:
>> +        return &regs->orig_vld;
>> +    case NAND_EBI2_ECC_BUF_CFG:
>> +        return &regs->ecc_buf_cfg;
>> +    case NAND_READ_LOCATION_0:
>> +        return &regs->read_location0;
>> +    case NAND_READ_LOCATION_1:
>> +        return &regs->read_location1;
>> +    case NAND_READ_LOCATION_2:
>> +        return &regs->read_location2;
>> +    case NAND_READ_LOCATION_3:
>> +        return &regs->read_location3;
>> +    case NAND_READ_LOCATION_LAST_CW_0:
>> +        return &regs->read_location_last0;
>> +    case NAND_READ_LOCATION_LAST_CW_1:
>> +        return &regs->read_location_last1;
>> +    case NAND_READ_LOCATION_LAST_CW_2:
>> +        return &regs->read_location_last2;
>> +    case NAND_READ_LOCATION_LAST_CW_3:
>> +        return &regs->read_location_last3;
>> +    default:
>> +        return NULL;
>> +    }
>> +}
>> +EXPORT_SYMBOL(offset_to_nandc_reg);
>> +
>> +/* reset the register read buffer for next NAND operation */
>> +void clear_read_regs(struct qcom_nand_controller *nandc)
>> +{
>> +    nandc->reg_read_pos = 0;
>> +    nandc_read_buffer_sync(nandc, false);
>> +}
>> +EXPORT_SYMBOL(clear_read_regs);
>> +
>> +int prep_adm_dma_desc(struct qcom_nand_controller *nandc, bool read,
>> +              int reg_off, const void *vaddr, int size,
>> +                 bool flow_control)
>> +{
>> +    struct desc_info *desc;
>> +    struct dma_async_tx_descriptor *dma_desc;
>> +    struct scatterlist *sgl;
>> +    struct dma_slave_config slave_conf;
>> +    struct qcom_adm_peripheral_config periph_conf = {};
>> +    enum dma_transfer_direction dir_eng;
>> +    int ret;
>> +
>> +    desc = kzalloc(sizeof(*desc), GFP_KERNEL);
>> +    if (!desc)
>> +        return -ENOMEM;
>> +
>> +    sgl = &desc->adm_sgl;
>> +
>> +    sg_init_one(sgl, vaddr, size);
>> +
>> +    if (read) {
>> +        dir_eng = DMA_DEV_TO_MEM;
>> +        desc->dir = DMA_FROM_DEVICE;
>> +    } else {
>> +        dir_eng = DMA_MEM_TO_DEV;
>> +        desc->dir = DMA_TO_DEVICE;
>> +    }
>> +
>> +    ret = dma_map_sg(nandc->dev, sgl, 1, desc->dir);
>> +    if (ret == 0) {
>> +        ret = -ENOMEM;
>> +        goto err;
>> +    }
>> +
>> +    memset(&slave_conf, 0x00, sizeof(slave_conf));
>> +
>> +    slave_conf.device_fc = flow_control;
>> +    if (read) {
>> +        slave_conf.src_maxburst = 16;
>> +        slave_conf.src_addr = nandc->base_dma + reg_off;
>> +        if (nandc->data_crci) {
>> +            periph_conf.crci = nandc->data_crci;
>> +            slave_conf.peripheral_config = &periph_conf;
>> +            slave_conf.peripheral_size = sizeof(periph_conf);
>> +        }
>> +    } else {
>> +        slave_conf.dst_maxburst = 16;
>> +        slave_conf.dst_addr = nandc->base_dma + reg_off;
>> +        if (nandc->cmd_crci) {
>> +            periph_conf.crci = nandc->cmd_crci;
>> +            slave_conf.peripheral_config = &periph_conf;
>> +            slave_conf.peripheral_size = sizeof(periph_conf);
>> +        }
>> +    }
>> +
>> +    ret = dmaengine_slave_config(nandc->chan, &slave_conf);
>> +    if (ret) {
>> +        dev_err(nandc->dev, "failed to configure dma channel\n");
>> +        goto err;
>> +    }
>> +
>> +    dma_desc = dmaengine_prep_slave_sg(nandc->chan, sgl, 1, dir_eng, 0);
>> +    if (!dma_desc) {
>> +        dev_err(nandc->dev, "failed to prepare desc\n");
>> +        ret = -EINVAL;
>> +        goto err;
>> +    }
>> +
>> +    desc->dma_desc = dma_desc;
>> +
>> +    list_add_tail(&desc->node, &nandc->desc_list);
>> +
>> +    return 0;
>> +err:
>> +    kfree(desc);
>> +
>> +    return ret;
>> +}
>> +EXPORT_SYMBOL(prep_adm_dma_desc);
>> +
>> +/* helpers to submit/free our list of dma descriptors */
>> +int submit_descs(struct qcom_nand_controller *nandc)
>> +{
>> +    struct desc_info *desc, *n;
>> +    dma_cookie_t cookie = 0;
>> +    struct bam_transaction *bam_txn = nandc->bam_txn;
>> +    int ret = 0;
>> +
>> +    if (nandc->props->is_bam) {
>> +        if (bam_txn->rx_sgl_pos > bam_txn->rx_sgl_start) {
>> +            ret = prepare_bam_async_desc(nandc, nandc->rx_chan, 0);
>> +            if (ret)
>> +                goto err_unmap_free_desc;
>> +        }
>> +
>> +        if (bam_txn->tx_sgl_pos > bam_txn->tx_sgl_start) {
>> +            ret = prepare_bam_async_desc(nandc, nandc->tx_chan,
>> +                             DMA_PREP_INTERRUPT);
>> +            if (ret)
>> +                goto err_unmap_free_desc;
>> +        }
>> +
>> +        if (bam_txn->cmd_sgl_pos > bam_txn->cmd_sgl_start) {
>> +            ret = prepare_bam_async_desc(nandc, nandc->cmd_chan,
>> +                             DMA_PREP_CMD);
>> +            if (ret)
>> +                goto err_unmap_free_desc;
>> +        }
>> +    }
>> +
>> +    list_for_each_entry(desc, &nandc->desc_list, node)
>> +        cookie = dmaengine_submit(desc->dma_desc);
>> +
>> +    if (nandc->props->is_bam) {
>> +        bam_txn->last_cmd_desc->callback = qpic_bam_dma_done;
>> +        bam_txn->last_cmd_desc->callback_param = bam_txn;
>> +        if (bam_txn->last_data_desc) {
>> +            bam_txn->last_data_desc->callback = qpic_bam_dma_done;
>> +            bam_txn->last_data_desc->callback_param = bam_txn;
>> +            bam_txn->wait_second_completion = true;
>> +        }
>> +
>> +        dma_async_issue_pending(nandc->tx_chan);
>> +        dma_async_issue_pending(nandc->rx_chan);
>> +        dma_async_issue_pending(nandc->cmd_chan);
>> +
>> +        if (!wait_for_completion_timeout(&bam_txn->txn_done,
>> +                         QPIC_NAND_COMPLETION_TIMEOUT))
>> +            ret = -ETIMEDOUT;
>> +    } else {
>> +        if (dma_sync_wait(nandc->chan, cookie) != DMA_COMPLETE)
>> +            ret = -ETIMEDOUT;
>> +    }
>> +
>> +err_unmap_free_desc:
>> +    /*
>> +     * Unmap the dma sg_list and free the desc allocated by both
>> +     * prepare_bam_async_desc() and prep_adm_dma_desc() functions.
>> +     */
>> +    list_for_each_entry_safe(desc, n, &nandc->desc_list, node) {
>> +        list_del(&desc->node);
>> +
>> +        if (nandc->props->is_bam)
>> +            dma_unmap_sg(nandc->dev, desc->bam_sgl,
>> +                     desc->sgl_cnt, desc->dir);
>> +        else
>> +            dma_unmap_sg(nandc->dev, &desc->adm_sgl, 1,
>> +                     desc->dir);
>> +
>> +        kfree(desc);
>> +    }
>> +
>> +    return ret;
>> +}
>> +EXPORT_SYMBOL(submit_descs);
>> +
>> +/*
>> + * Maps the scatter gather list for DMA transfer and forms the DMA descriptor
>> + * for BAM. This descriptor will be added in the NAND DMA descriptor queue
>> + * which will be submitted to DMA engine.
>> + */
>> +int prepare_bam_async_desc(struct qcom_nand_controller *nandc,
>> +               struct dma_chan *chan,
>> +                  unsigned long flags)
>> +{
>> +    struct desc_info *desc;
>> +    struct scatterlist *sgl;
>> +    unsigned int sgl_cnt;
>> +    int ret;
>> +    struct bam_transaction *bam_txn = nandc->bam_txn;
>> +    enum dma_transfer_direction dir_eng;
>> +    struct dma_async_tx_descriptor *dma_desc;
>> +
>> +    desc = kzalloc(sizeof(*desc), GFP_KERNEL);
>> +    if (!desc)
>> +        return -ENOMEM;
>> +
>> +    if (chan == nandc->cmd_chan) {
>> +        sgl = &bam_txn->cmd_sgl[bam_txn->cmd_sgl_start];
>> +        sgl_cnt = bam_txn->cmd_sgl_pos - bam_txn->cmd_sgl_start;
>> +        bam_txn->cmd_sgl_start = bam_txn->cmd_sgl_pos;
>> +        dir_eng = DMA_MEM_TO_DEV;
>> +        desc->dir = DMA_TO_DEVICE;
>> +    } else if (chan == nandc->tx_chan) {
>> +        sgl = &bam_txn->data_sgl[bam_txn->tx_sgl_start];
>> +        sgl_cnt = bam_txn->tx_sgl_pos - bam_txn->tx_sgl_start;
>> +        bam_txn->tx_sgl_start = bam_txn->tx_sgl_pos;
>> +        dir_eng = DMA_MEM_TO_DEV;
>> +        desc->dir = DMA_TO_DEVICE;
>> +    } else {
>> +        sgl = &bam_txn->data_sgl[bam_txn->rx_sgl_start];
>> +        sgl_cnt = bam_txn->rx_sgl_pos - bam_txn->rx_sgl_start;
>> +        bam_txn->rx_sgl_start = bam_txn->rx_sgl_pos;
>> +        dir_eng = DMA_DEV_TO_MEM;
>> +        desc->dir = DMA_FROM_DEVICE;
>> +    }
>> +
>> +    sg_mark_end(sgl + sgl_cnt - 1);
>> +    ret = dma_map_sg(nandc->dev, sgl, sgl_cnt, desc->dir);
>> +    if (ret == 0) {
>> +        dev_err(nandc->dev, "failure in mapping desc\n");
>> +        kfree(desc);
>> +        return -ENOMEM;
>> +    }
>> +
>> +    desc->sgl_cnt = sgl_cnt;
>> +    desc->bam_sgl = sgl;
>> +
>> +    dma_desc = dmaengine_prep_slave_sg(chan, sgl, sgl_cnt, dir_eng,
>> +                       flags);
>> +
>> +    if (!dma_desc) {
>> +        dev_err(nandc->dev, "failure in prep desc\n");
>> +        dma_unmap_sg(nandc->dev, sgl, sgl_cnt, desc->dir);
>> +        kfree(desc);
>> +        return -EINVAL;
>> +    }
>> +
>> +    desc->dma_desc = dma_desc;
>> +
>> +    /* update last data/command descriptor */
>> +    if (chan == nandc->cmd_chan)
>> +        bam_txn->last_cmd_desc = dma_desc;
>> +    else
>> +        bam_txn->last_data_desc = dma_desc;
>> +
>> +    list_add_tail(&desc->node, &nandc->desc_list);
>> +
>> +    return 0;
>> +}
>> +EXPORT_SYMBOL(prepare_bam_async_desc);
>> +
>> +/*
>> + * Prepares the command descriptor for BAM DMA which will be used for NAND
>> + * register reads and writes. The command descriptor requires the command
>> + * to be formed in command element type so this function uses the command
>> + * element from bam transaction ce array and fills the same with required
>> + * data. A single SGL can contain multiple command elements so
>> + * NAND_BAM_NEXT_SGL will be used for starting the separate SGL
>> + * after the current command element.
>> + */
>> +int prep_bam_dma_desc_cmd(struct qcom_nand_controller *nandc, bool read,
>> +              int reg_off, const void *vaddr,
>> +                 int size, unsigned int flags)
>> +{
>> +    int bam_ce_size;
>> +    int i, ret;
>> +    struct bam_cmd_element *bam_ce_buffer;
>> +    struct bam_transaction *bam_txn = nandc->bam_txn;
>> +
>> +    bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_pos];
>> +
>> +    /* fill the command desc */
>> +    for (i = 0; i < size; i++) {
>> +        if (read)
>> +            bam_prep_ce(&bam_ce_buffer[i],
>> +                    nandc_reg_phys(nandc, reg_off + 4 * i),
>> +                    BAM_READ_COMMAND,
>> +                    reg_buf_dma_addr(nandc,
>> +                             (__le32 *)vaddr + i));
>> +        else
>> +            bam_prep_ce_le32(&bam_ce_buffer[i],
>> +                     nandc_reg_phys(nandc, reg_off + 4 * i),
>> +                     BAM_WRITE_COMMAND,
>> +                     *((__le32 *)vaddr + i));
>> +    }
>> +
>> +    bam_txn->bam_ce_pos += size;
>> +
>> +    /* use the separate sgl after this command */
>> +    if (flags & NAND_BAM_NEXT_SGL) {
>> +        bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_start];
>> +        bam_ce_size = (bam_txn->bam_ce_pos -
>> +                bam_txn->bam_ce_start) *
>> +                sizeof(struct bam_cmd_element);
>> +        sg_set_buf(&bam_txn->cmd_sgl[bam_txn->cmd_sgl_pos],
>> +               bam_ce_buffer, bam_ce_size);
>> +        bam_txn->cmd_sgl_pos++;
>> +        bam_txn->bam_ce_start = bam_txn->bam_ce_pos;
>> +
>> +        if (flags & NAND_BAM_NWD) {
>> +            ret = prepare_bam_async_desc(nandc, nandc->cmd_chan,
>> +                             DMA_PREP_FENCE |
>> +                             DMA_PREP_CMD);
>> +            if (ret)
>> +                return ret;
>> +        }
>> +    }
>> +
>> +    return 0;
>> +}
>> +EXPORT_SYMBOL(prep_bam_dma_desc_cmd);
>> +
>> +/*
>> + * Prepares the data descriptor for BAM DMA which will be used for NAND
>> + * data reads and writes.
>> + */
>> +int prep_bam_dma_desc_data(struct qcom_nand_controller *nandc, bool read,
>> +               const void *vaddr,
>> +                  int size, unsigned int flags)
>> +{
>> +    int ret;
>> +    struct bam_transaction *bam_txn = nandc->bam_txn;
>> +
>> +    if (read) {
>> +        sg_set_buf(&bam_txn->data_sgl[bam_txn->rx_sgl_pos],
>> +               vaddr, size);
>> +        bam_txn->rx_sgl_pos++;
>> +    } else {
>> +        sg_set_buf(&bam_txn->data_sgl[bam_txn->tx_sgl_pos],
>> +               vaddr, size);
>> +        bam_txn->tx_sgl_pos++;
>> +
>> +        /*
>> +         * BAM will only set EOT for DMA_PREP_INTERRUPT so if this flag
>> +         * is not set, form the DMA descriptor
>> +         */
>> +        if (!(flags & NAND_BAM_NO_EOT)) {
>> +            ret = prepare_bam_async_desc(nandc, nandc->tx_chan,
>> +                             DMA_PREP_INTERRUPT);
>> +            if (ret)
>> +                return ret;
>> +        }
>> +    }
>> +
>> +    return 0;
>> +}
>> +EXPORT_SYMBOL(prep_bam_dma_desc_data);
>> +
>> +/*
>> + * read_reg_dma:    prepares a descriptor to read a given number of
>> + *            contiguous registers to the reg_read_buf pointer
>> + *
>> + * @first:        offset of the first register in the contiguous block
>> + * @num_regs:        number of registers to read
>> + * @flags:        flags to control DMA descriptor preparation
>> + */
>> +int read_reg_dma(struct qcom_nand_controller *nandc, int first,
>> +         int num_regs, unsigned int flags)
>> +{
>> +    bool flow_control = false;
>> +    void *vaddr;
>> +
>> +    vaddr = nandc->reg_read_buf + nandc->reg_read_pos;
>> +    nandc->reg_read_pos += num_regs;
>> +
>> +    if (first == NAND_DEV_CMD_VLD || first == NAND_DEV_CMD1)
>> +        first = dev_cmd_reg_addr(nandc, first);
>> +
>> +    if (nandc->props->is_bam)
>> +        return prep_bam_dma_desc_cmd(nandc, true, first, vaddr,
>> +                         num_regs, flags);
>> +
>> +    if (first == NAND_READ_ID || first == NAND_FLASH_STATUS)
>> +        flow_control = true;
>> +
>> +    return prep_adm_dma_desc(nandc, true, first, vaddr,
>> +                 num_regs * sizeof(u32), flow_control);
>> +}
>> +EXPORT_SYMBOL(read_reg_dma);
>> +
>> +/*
>> + * write_reg_dma:    prepares a descriptor to write a given number of
>> + *            contiguous registers
>> + *
>> + * @first:        offset of the first register in the contiguous block
>> + * @num_regs:        number of registers to write
>> + * @flags:        flags to control DMA descriptor preparation
>> + */
>> +int write_reg_dma(struct qcom_nand_controller *nandc, int first,
>> +          int num_regs, unsigned int flags)
>> +{
>> +    bool flow_control = false;
>> +    struct nandc_regs *regs = nandc->regs;
>> +    void *vaddr;
>> +
>> +    vaddr = offset_to_nandc_reg(regs, first);
>> +
>> +    if (first == NAND_ERASED_CW_DETECT_CFG) {
>> +        if (flags & NAND_ERASED_CW_SET)
>> +            vaddr = &regs->erased_cw_detect_cfg_set;
>> +        else
>> +            vaddr = &regs->erased_cw_detect_cfg_clr;
>> +    }
>> +
>> +    if (first == NAND_EXEC_CMD)
>> +        flags |= NAND_BAM_NWD;
>> +
>> +    if (first == NAND_DEV_CMD1_RESTORE || first == NAND_DEV_CMD1)
>> +        first = dev_cmd_reg_addr(nandc, NAND_DEV_CMD1);
>> +
>> +    if (first == NAND_DEV_CMD_VLD_RESTORE || first == NAND_DEV_CMD_VLD)
>> +        first = dev_cmd_reg_addr(nandc, NAND_DEV_CMD_VLD);
>> +
>> +    if (nandc->props->is_bam)
>> +        return prep_bam_dma_desc_cmd(nandc, false, first, vaddr,
>> +                         num_regs, flags);
>> +
>> +    if (first == NAND_FLASH_CMD)
>> +        flow_control = true;
>> +
>> +    return prep_adm_dma_desc(nandc, false, first, vaddr,
>> +                 num_regs * sizeof(u32), flow_control);
>> +}
>> +EXPORT_SYMBOL(write_reg_dma);
>> +
>> +/*
>> + * read_data_dma:    prepares a DMA descriptor to transfer data from the
>> + *            controller's internal buffer to the buffer 'vaddr'
>> + *
>> + * @reg_off:        offset within the controller's data buffer
>> + * @vaddr:        virtual address of the buffer we want to write to
>> + * @size:        DMA transaction size in bytes
>> + * @flags:        flags to control DMA descriptor preparation
>> + */
>> +int read_data_dma(struct qcom_nand_controller *nandc, int reg_off,
>> +          const u8 *vaddr, int size, unsigned int flags)
>> +{
>> +    if (nandc->props->is_bam)
>> +        return prep_bam_dma_desc_data(nandc, true, vaddr, size, flags);
>> +
>> +    return prep_adm_dma_desc(nandc, true, reg_off, vaddr, size, false);
>> +}
>> +EXPORT_SYMBOL(read_data_dma);
>> +
>> +/*
>> + * write_data_dma:    prepares a DMA descriptor to transfer data from
>> + *            'vaddr' to the controller's internal buffer
>> + *
>> + * @reg_off:        offset within the controller's data buffer
>> + * @vaddr:        virtual address of the buffer we want to read from
>> + * @size:        DMA transaction size in bytes
>> + * @flags:        flags to control DMA descriptor preparation
>> + */
>> +int write_data_dma(struct qcom_nand_controller *nandc, int reg_off,
>> +           const u8 *vaddr, int size, unsigned int flags)
>> +{
>> +    if (nandc->props->is_bam)
>> +        return prep_bam_dma_desc_data(nandc, false, vaddr, size, flags);
>> +
>> +    return prep_adm_dma_desc(nandc, false, reg_off, vaddr, size, false);
>> +}
>> +EXPORT_SYMBOL(write_data_dma);
>> +
>> +/* Allocates and Initializes the BAM transaction */
>> +struct bam_transaction *
>> +alloc_bam_transaction(struct qcom_nand_controller *nandc)
>> +{
>> +    struct bam_transaction *bam_txn;
>> +    size_t bam_txn_size;
>> +    unsigned int num_cw = nandc->max_cwperpage;
>> +    void *bam_txn_buf;
>> +
>> +    bam_txn_size =
>> +        sizeof(*bam_txn) + num_cw *
>> +        ((sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS) +
>> +        (sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL) +
>> +        (sizeof(*bam_txn->data_sgl) * QPIC_PER_CW_DATA_SGL));
>> +
>> +    bam_txn_buf = devm_kzalloc(nandc->dev, bam_txn_size, GFP_KERNEL);
>> +    if (!bam_txn_buf)
>> +        return NULL;
>> +
>> +    bam_txn = bam_txn_buf;
>> +    bam_txn_buf += sizeof(*bam_txn);
>> +
>> +    bam_txn->bam_ce = bam_txn_buf;
>> +    bam_txn_buf +=
>> +        sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS * num_cw;
>> +
>> +    bam_txn->cmd_sgl = bam_txn_buf;
>> +    bam_txn_buf +=
>> +        sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL * num_cw;
>> +
>> +    bam_txn->data_sgl = bam_txn_buf;
>> +
>> +    init_completion(&bam_txn->txn_done);
>> +
>> +    return bam_txn;
>> +}
>> +EXPORT_SYMBOL(alloc_bam_transaction);
>> +
>> +/* Clears the BAM transaction indexes */
>> +void clear_bam_transaction(struct qcom_nand_controller *nandc)
>> +{
>> +    struct bam_transaction *bam_txn = nandc->bam_txn;
>> +
>> +    if (!nandc->props->is_bam)
>> +        return;
>> +
>> +    bam_txn->bam_ce_pos = 0;
>> +    bam_txn->bam_ce_start = 0;
>> +    bam_txn->cmd_sgl_pos = 0;
>> +    bam_txn->cmd_sgl_start = 0;
>> +    bam_txn->tx_sgl_pos = 0;
>> +    bam_txn->tx_sgl_start = 0;
>> +    bam_txn->rx_sgl_pos = 0;
>> +    bam_txn->rx_sgl_start = 0;
>> +    bam_txn->last_data_desc = NULL;
>> +    bam_txn->wait_second_completion = false;
>> +
>> +    sg_init_table(bam_txn->cmd_sgl, nandc->max_cwperpage *
>> +              QPIC_PER_CW_CMD_SGL);
>> +    sg_init_table(bam_txn->data_sgl, nandc->max_cwperpage *
>> +              QPIC_PER_CW_DATA_SGL);
>> +
>> +    reinit_completion(&bam_txn->txn_done);
>> +}
>> +EXPORT_SYMBOL(clear_bam_transaction);
>> +
>> +void qcom_nandc_unalloc(struct qcom_nand_controller *nandc)
>> +{
>> +    if (nandc->props->is_bam) {
>> +        if (!dma_mapping_error(nandc->dev, nandc->reg_read_dma))
>> +            dma_unmap_single(nandc->dev, nandc->reg_read_dma,
>> +                     MAX_REG_RD *
>> +                     sizeof(*nandc->reg_read_buf),
>> +                     DMA_FROM_DEVICE);
>> +
>> +        if (nandc->tx_chan)
>> +            dma_release_channel(nandc->tx_chan);
>> +
>> +        if (nandc->rx_chan)
>> +            dma_release_channel(nandc->rx_chan);
>> +
>> +        if (nandc->cmd_chan)
>> +            dma_release_channel(nandc->cmd_chan);
>> +    } else {
>> +        if (nandc->chan)
>> +            dma_release_channel(nandc->chan);
>> +    }
>> +}
>> +EXPORT_SYMBOL(qcom_nandc_unalloc);
>> +
>> +int qcom_nandc_alloc(struct qcom_nand_controller *nandc)
>> +{
>> +    int ret;
>> +
>> +    ret = dma_set_coherent_mask(nandc->dev, DMA_BIT_MASK(32));
>> +    if (ret) {
>> +        dev_err(nandc->dev, "failed to set DMA mask\n");
>> +        return ret;
>> +    }
>> +
>> +    /*
>> +     * we use the internal buffer for reading ONFI params, reading small
>> +     * data like ID and status, and preforming read-copy-write operations
>> +     * when writing to a codeword partially. 532 is the maximum possible
>> +     * size of a codeword for our nand controller
>> +     */
>> +    nandc->buf_size = 532;
>> +
>> +    nandc->data_buffer = devm_kzalloc(nandc->dev, nandc->buf_size, GFP_KERNEL);
>> +    if (!nandc->data_buffer)
>> +        return -ENOMEM;
>> +
>> +    nandc->regs = devm_kzalloc(nandc->dev, sizeof(*nandc->regs), GFP_KERNEL);
>> +    if (!nandc->regs)
>> +        return -ENOMEM;
>> +
>> +    nandc->reg_read_buf = devm_kcalloc(nandc->dev, MAX_REG_RD,
>> +                       sizeof(*nandc->reg_read_buf),
>> +                       GFP_KERNEL);
>> +    if (!nandc->reg_read_buf)
>> +        return -ENOMEM;
>> +
>> +    if (nandc->props->is_bam) {
>> +        nandc->reg_read_dma =
>> +            dma_map_single(nandc->dev, nandc->reg_read_buf,
>> +                       MAX_REG_RD *
>> +                       sizeof(*nandc->reg_read_buf),
>> +                       DMA_FROM_DEVICE);
>> +        if (dma_mapping_error(nandc->dev, nandc->reg_read_dma)) {
>> +            dev_err(nandc->dev, "failed to DMA MAP reg buffer\n");
>> +            return -EIO;
>> +        }
>> +
>> +        nandc->tx_chan = dma_request_chan(nandc->dev, "tx");
>> +        if (IS_ERR(nandc->tx_chan)) {
>> +            ret = PTR_ERR(nandc->tx_chan);
>> +            nandc->tx_chan = NULL;
>> +            dev_err_probe(nandc->dev, ret,
>> +                      "tx DMA channel request failed\n");
>> +            goto unalloc;
>> +        }
>> +
>> +        nandc->rx_chan = dma_request_chan(nandc->dev, "rx");
>> +        if (IS_ERR(nandc->rx_chan)) {
>> +            ret = PTR_ERR(nandc->rx_chan);
>> +            nandc->rx_chan = NULL;
>> +            dev_err_probe(nandc->dev, ret,
>> +                      "rx DMA channel request failed\n");
>> +            goto unalloc;
>> +        }
>> +
>> +        nandc->cmd_chan = dma_request_chan(nandc->dev, "cmd");
>> +        if (IS_ERR(nandc->cmd_chan)) {
>> +            ret = PTR_ERR(nandc->cmd_chan);
>> +            nandc->cmd_chan = NULL;
>> +            dev_err_probe(nandc->dev, ret,
>> +                      "cmd DMA channel request failed\n");
>> +            goto unalloc;
>> +        }
>> +
>> +        /*
>> +         * Initially allocate BAM transaction to read ONFI param page.
>> +         * After detecting all the devices, this BAM transaction will
>> +         * be freed and the next BAM transaction will be allocated with
>> +         * maximum codeword size
>> +         */
>> +        nandc->max_cwperpage = 1;
>> +        nandc->bam_txn = alloc_bam_transaction(nandc);
>> +        if (!nandc->bam_txn) {
>> +            dev_err(nandc->dev,
>> +                "failed to allocate bam transaction\n");
>> +            ret = -ENOMEM;
>> +            goto unalloc;
>> +        }
>> +    } else {
>> +        nandc->chan = dma_request_chan(nandc->dev, "rxtx");
>> +        if (IS_ERR(nandc->chan)) {
>> +            ret = PTR_ERR(nandc->chan);
>> +            nandc->chan = NULL;
>> +            dev_err_probe(nandc->dev, ret,
>> +                      "rxtx DMA channel request failed\n");
>> +            return ret;
>> +        }
>> +    }
>> +
>> +    INIT_LIST_HEAD(&nandc->desc_list);
>> +    INIT_LIST_HEAD(&nandc->host_list);
>> +
>> +    return 0;
>> +unalloc:
>> +    qcom_nandc_unalloc(nandc);
>> +    return ret;
>> +}
>> +EXPORT_SYMBOL(qcom_nandc_alloc);
>> diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
>> index b079605c84d3..75c6ca698c85 100644
>> --- a/drivers/mtd/nand/raw/qcom_nandc.c
>> +++ b/drivers/mtd/nand/raw/qcom_nandc.c
>> @@ -2,186 +2,7 @@
>>   /*
>>    * Copyright (c) 2016, The Linux Foundation. All rights reserved.
>>    */
>> -#include <linux/bitops.h>
>> -#include <linux/clk.h>
>> -#include <linux/delay.h>
>> -#include <linux/dmaengine.h>
>> -#include <linux/dma-mapping.h>
>> -#include <linux/dma/qcom_adm.h>
>> -#include <linux/dma/qcom_bam_dma.h>
>> -#include <linux/module.h>
>> -#include <linux/mtd/partitions.h>
>> -#include <linux/mtd/rawnand.h>
>> -#include <linux/of.h>
>> -#include <linux/platform_device.h>
>> -#include <linux/slab.h>
>> -
>> -/* NANDc reg offsets */
>> -#define    NAND_FLASH_CMD            0x00
>> -#define    NAND_ADDR0            0x04
>> -#define    NAND_ADDR1            0x08
>> -#define    NAND_FLASH_CHIP_SELECT        0x0c
>> -#define    NAND_EXEC_CMD            0x10
>> -#define    NAND_FLASH_STATUS        0x14
>> -#define    NAND_BUFFER_STATUS        0x18
>> -#define    NAND_DEV0_CFG0            0x20
>> -#define    NAND_DEV0_CFG1            0x24
>> -#define    NAND_DEV0_ECC_CFG        0x28
>> -#define    NAND_AUTO_STATUS_EN        0x2c
>> -#define    NAND_DEV1_CFG0            0x30
>> -#define    NAND_DEV1_CFG1            0x34
>> -#define    NAND_READ_ID            0x40
>> -#define    NAND_READ_STATUS        0x44
>> -#define    NAND_DEV_CMD0            0xa0
>> -#define    NAND_DEV_CMD1            0xa4
>> -#define    NAND_DEV_CMD2            0xa8
>> -#define    NAND_DEV_CMD_VLD        0xac
>> -#define    SFLASHC_BURST_CFG        0xe0
>> -#define    NAND_ERASED_CW_DETECT_CFG    0xe8
>> -#define    NAND_ERASED_CW_DETECT_STATUS    0xec
>> -#define    NAND_EBI2_ECC_BUF_CFG        0xf0
>> -#define    FLASH_BUF_ACC            0x100
>> -
>> -#define    NAND_CTRL            0xf00
>> -#define    NAND_VERSION            0xf08
>> -#define    NAND_READ_LOCATION_0        0xf20
>> -#define    NAND_READ_LOCATION_1        0xf24
>> -#define    NAND_READ_LOCATION_2        0xf28
>> -#define    NAND_READ_LOCATION_3        0xf2c
>> -#define    NAND_READ_LOCATION_LAST_CW_0    0xf40
>> -#define    NAND_READ_LOCATION_LAST_CW_1    0xf44
>> -#define    NAND_READ_LOCATION_LAST_CW_2    0xf48
>> -#define    NAND_READ_LOCATION_LAST_CW_3    0xf4c
>> -
>> -/* dummy register offsets, used by write_reg_dma */
>> -#define    NAND_DEV_CMD1_RESTORE        0xdead
>> -#define    NAND_DEV_CMD_VLD_RESTORE    0xbeef
>> -
>> -/* NAND_FLASH_CMD bits */
>> -#define    PAGE_ACC            BIT(4)
>> -#define    LAST_PAGE            BIT(5)
>> -
>> -/* NAND_FLASH_CHIP_SELECT bits */
>> -#define    NAND_DEV_SEL            0
>> -#define    DM_EN                BIT(2)
>> -
>> -/* NAND_FLASH_STATUS bits */
>> -#define    FS_OP_ERR            BIT(4)
>> -#define    FS_READY_BSY_N            BIT(5)
>> -#define    FS_MPU_ERR            BIT(8)
>> -#define    FS_DEVICE_STS_ERR        BIT(16)
>> -#define    FS_DEVICE_WP            BIT(23)
>> -
>> -/* NAND_BUFFER_STATUS bits */
>> -#define    BS_UNCORRECTABLE_BIT        BIT(8)
>> -#define    BS_CORRECTABLE_ERR_MSK        0x1f
>> -
>> -/* NAND_DEVn_CFG0 bits */
>> -#define    DISABLE_STATUS_AFTER_WRITE    4
>> -#define    CW_PER_PAGE            6
>> -#define    UD_SIZE_BYTES            9
>> -#define    UD_SIZE_BYTES_MASK        GENMASK(18, 9)
>> -#define    ECC_PARITY_SIZE_BYTES_RS    19
>> -#define    SPARE_SIZE_BYTES        23
>> -#define    SPARE_SIZE_BYTES_MASK        GENMASK(26, 23)
>> -#define    NUM_ADDR_CYCLES            27
>> -#define    STATUS_BFR_READ            30
>> -#define    SET_RD_MODE_AFTER_STATUS    31
>> -
>> -/* NAND_DEVn_CFG0 bits */
>> -#define    DEV0_CFG1_ECC_DISABLE        0
>> -#define    WIDE_FLASH            1
>> -#define    NAND_RECOVERY_CYCLES        2
>> -#define    CS_ACTIVE_BSY            5
>> -#define    BAD_BLOCK_BYTE_NUM        6
>> -#define    BAD_BLOCK_IN_SPARE_AREA        16
>> -#define    WR_RD_BSY_GAP            17
>> -#define    ENABLE_BCH_ECC            27
>> -
>> -/* NAND_DEV0_ECC_CFG bits */
>> -#define    ECC_CFG_ECC_DISABLE        0
>> -#define    ECC_SW_RESET            1
>> -#define    ECC_MODE            4
>> -#define    ECC_PARITY_SIZE_BYTES_BCH    8
>> -#define    ECC_NUM_DATA_BYTES        16
>> -#define    ECC_NUM_DATA_BYTES_MASK        GENMASK(25, 16)
>> -#define    ECC_FORCE_CLK_OPEN        30
>> -
>> -/* NAND_DEV_CMD1 bits */
>> -#define    READ_ADDR            0
>> -
>> -/* NAND_DEV_CMD_VLD bits */
>> -#define    READ_START_VLD            BIT(0)
>> -#define    READ_STOP_VLD            BIT(1)
>> -#define    WRITE_START_VLD            BIT(2)
>> -#define    ERASE_START_VLD            BIT(3)
>> -#define    SEQ_READ_START_VLD        BIT(4)
>> -
>> -/* NAND_EBI2_ECC_BUF_CFG bits */
>> -#define    NUM_STEPS            0
>> -
>> -/* NAND_ERASED_CW_DETECT_CFG bits */
>> -#define    ERASED_CW_ECC_MASK        1
>> -#define    AUTO_DETECT_RES            0
>> -#define    MASK_ECC            BIT(ERASED_CW_ECC_MASK)
>> -#define    RESET_ERASED_DET        BIT(AUTO_DETECT_RES)
>> -#define    ACTIVE_ERASED_DET        (0 << AUTO_DETECT_RES)
>> -#define    CLR_ERASED_PAGE_DET        (RESET_ERASED_DET | MASK_ECC)
>> -#define    SET_ERASED_PAGE_DET        (ACTIVE_ERASED_DET | MASK_ECC)
>> -
>> -/* NAND_ERASED_CW_DETECT_STATUS bits */
>> -#define    PAGE_ALL_ERASED            BIT(7)
>> -#define    CODEWORD_ALL_ERASED        BIT(6)
>> -#define    PAGE_ERASED            BIT(5)
>> -#define    CODEWORD_ERASED            BIT(4)
>> -#define    ERASED_PAGE            (PAGE_ALL_ERASED | PAGE_ERASED)
>> -#define    ERASED_CW            (CODEWORD_ALL_ERASED | CODEWORD_ERASED)
>> -
>> -/* NAND_READ_LOCATION_n bits */
>> -#define READ_LOCATION_OFFSET        0
>> -#define READ_LOCATION_SIZE        16
>> -#define READ_LOCATION_LAST        31
>> -
>> -/* Version Mask */
>> -#define    NAND_VERSION_MAJOR_MASK        0xf0000000
>> -#define    NAND_VERSION_MAJOR_SHIFT    28
>> -#define    NAND_VERSION_MINOR_MASK        0x0fff0000
>> -#define    NAND_VERSION_MINOR_SHIFT    16
>> -
>> -/* NAND OP_CMDs */
>> -#define    OP_PAGE_READ            0x2
>> -#define    OP_PAGE_READ_WITH_ECC        0x3
>> -#define    OP_PAGE_READ_WITH_ECC_SPARE    0x4
>> -#define    OP_PAGE_READ_ONFI_READ        0x5
>> -#define    OP_PROGRAM_PAGE            0x6
>> -#define    OP_PAGE_PROGRAM_WITH_ECC    0x7
>> -#define    OP_PROGRAM_PAGE_SPARE        0x9
>> -#define    OP_BLOCK_ERASE            0xa
>> -#define    OP_CHECK_STATUS            0xc
>> -#define    OP_FETCH_ID            0xb
>> -#define    OP_RESET_DEVICE            0xd
>> -
>> -/* Default Value for NAND_DEV_CMD_VLD */
>> -#define NAND_DEV_CMD_VLD_VAL        (READ_START_VLD | WRITE_START_VLD | \
>> -                     ERASE_START_VLD | SEQ_READ_START_VLD)
>> -
>> -/* NAND_CTRL bits */
>> -#define    BAM_MODE_EN            BIT(0)
>> -
>> -/*
>> - * the NAND controller performs reads/writes with ECC in 516 byte chunks.
>> - * the driver calls the chunks 'step' or 'codeword' interchangeably
>> - */
>> -#define    NANDC_STEP_SIZE            512
>> -
>> -/*
>> - * the largest page size we support is 8K, this will have 16 steps/codewords
>> - * of 512 bytes each
>> - */
>> -#define    MAX_NUM_STEPS            (SZ_8K / NANDC_STEP_SIZE)
>> -
>> -/* we read at most 3 registers per codeword scan */
>> -#define    MAX_REG_RD            (3 * MAX_NUM_STEPS)
>> +#include <linux/mtd/nand-qpic-common.h>
>>   /* ECC modes supported by the controller */
>>   #define    ECC_NONE    BIT(0)
>> @@ -200,247 +21,6 @@ nandc_set_reg(chip, reg,            \
>>             ((cw_offset) << READ_LOCATION_OFFSET) |        \
>>             ((read_size) << READ_LOCATION_SIZE) |            \
>>             ((is_last_read_loc) << READ_LOCATION_LAST))
>> -/*
>> - * Returns the actual register address for all NAND_DEV_ registers
>> - * (i.e. NAND_DEV_CMD0, NAND_DEV_CMD1, NAND_DEV_CMD2 and NAND_DEV_CMD_VLD)
>> - */
>> -#define dev_cmd_reg_addr(nandc, reg) ((nandc)->props->dev_cmd_reg_start + (reg))
>> -
>> -/* Returns the NAND register physical address */
>> -#define nandc_reg_phys(chip, offset) ((chip)->base_phys + (offset))
>> -
>> -/* Returns the dma address for reg read buffer */
>> -#define reg_buf_dma_addr(chip, vaddr) \
>> -    ((chip)->reg_read_dma + \
>> -    ((u8 *)(vaddr) - (u8 *)(chip)->reg_read_buf))
>> -
>> -#define QPIC_PER_CW_CMD_ELEMENTS    32
>> -#define QPIC_PER_CW_CMD_SGL        32
>> -#define QPIC_PER_CW_DATA_SGL        8
>> -
>> -#define QPIC_NAND_COMPLETION_TIMEOUT    msecs_to_jiffies(2000)
>> -
>> -/*
>> - * Flags used in DMA descriptor preparation helper functions
>> - * (i.e. read_reg_dma/write_reg_dma/read_data_dma/write_data_dma)
>> - */
>> -/* Don't set the EOT in current tx BAM sgl */
>> -#define NAND_BAM_NO_EOT            BIT(0)
>> -/* Set the NWD flag in current BAM sgl */
>> -#define NAND_BAM_NWD            BIT(1)
>> -/* Finish writing in the current BAM sgl and start writing in another BAM sgl */
>> -#define NAND_BAM_NEXT_SGL        BIT(2)
>> -/*
>> - * Erased codeword status is being used two times in single transfer so this
>> - * flag will determine the current value of erased codeword status register
>> - */
>> -#define NAND_ERASED_CW_SET        BIT(4)
>> -
>> -#define MAX_ADDRESS_CYCLE        5
>> -
>> -/*
>> - * This data type corresponds to the BAM transaction which will be used for all
>> - * NAND transfers.
>> - * @bam_ce - the array of BAM command elements
>> - * @cmd_sgl - sgl for NAND BAM command pipe
>> - * @data_sgl - sgl for NAND BAM consumer/producer pipe
>> - * @last_data_desc - last DMA desc in data channel (tx/rx).
>> - * @last_cmd_desc - last DMA desc in command channel.
>> - * @txn_done - completion for NAND transfer.
>> - * @bam_ce_pos - the index in bam_ce which is available for next sgl
>> - * @bam_ce_start - the index in bam_ce which marks the start position ce
>> - *           for current sgl. It will be used for size calculation
>> - *           for current sgl
>> - * @cmd_sgl_pos - current index in command sgl.
>> - * @cmd_sgl_start - start index in command sgl.
>> - * @tx_sgl_pos - current index in data sgl for tx.
>> - * @tx_sgl_start - start index in data sgl for tx.
>> - * @rx_sgl_pos - current index in data sgl for rx.
>> - * @rx_sgl_start - start index in data sgl for rx.
>> - * @wait_second_completion - wait for second DMA desc completion before making
>> - *                 the NAND transfer completion.
>> - */
>> -struct bam_transaction {
>> -    struct bam_cmd_element *bam_ce;
>> -    struct scatterlist *cmd_sgl;
>> -    struct scatterlist *data_sgl;
>> -    struct dma_async_tx_descriptor *last_data_desc;
>> -    struct dma_async_tx_descriptor *last_cmd_desc;
>> -    struct completion txn_done;
>> -    u32 bam_ce_pos;
>> -    u32 bam_ce_start;
>> -    u32 cmd_sgl_pos;
>> -    u32 cmd_sgl_start;
>> -    u32 tx_sgl_pos;
>> -    u32 tx_sgl_start;
>> -    u32 rx_sgl_pos;
>> -    u32 rx_sgl_start;
>> -    bool wait_second_completion;
>> -};
>> -
>> -/*
>> - * This data type corresponds to the nand dma descriptor
>> - * @dma_desc - low level DMA engine descriptor
>> - * @list - list for desc_info
>> - *
>> - * @adm_sgl - sgl which will be used for single sgl dma descriptor. Only used by
>> - *          ADM
>> - * @bam_sgl - sgl which will be used for dma descriptor. Only used by BAM
>> - * @sgl_cnt - number of SGL in bam_sgl. Only used by BAM
>> - * @dir - DMA transfer direction
>> - */
>> -struct desc_info {
>> -    struct dma_async_tx_descriptor *dma_desc;
>> -    struct list_head node;
>> -
>> -    union {
>> -        struct scatterlist adm_sgl;
>> -        struct {
>> -            struct scatterlist *bam_sgl;
>> -            int sgl_cnt;
>> -        };
>> -    };
>> -    enum dma_data_direction dir;
>> -};
>> -
>> -/*
>> - * holds the current register values that we want to write. acts as a contiguous
>> - * chunk of memory which we use to write the controller registers through DMA.
>> - */
>> -struct nandc_regs {
>> -    __le32 cmd;
>> -    __le32 addr0;
>> -    __le32 addr1;
>> -    __le32 chip_sel;
>> -    __le32 exec;
>> -
>> -    __le32 cfg0;
>> -    __le32 cfg1;
>> -    __le32 ecc_bch_cfg;
>> -
>> -    __le32 clrflashstatus;
>> -    __le32 clrreadstatus;
>> -
>> -    __le32 cmd1;
>> -    __le32 vld;
>> -
>> -    __le32 orig_cmd1;
>> -    __le32 orig_vld;
>> -
>> -    __le32 ecc_buf_cfg;
>> -    __le32 read_location0;
>> -    __le32 read_location1;
>> -    __le32 read_location2;
>> -    __le32 read_location3;
>> -    __le32 read_location_last0;
>> -    __le32 read_location_last1;
>> -    __le32 read_location_last2;
>> -    __le32 read_location_last3;
>> -
>> -    __le32 erased_cw_detect_cfg_clr;
>> -    __le32 erased_cw_detect_cfg_set;
>> -};
>> -
>> -/*
>> - * NAND controller data struct
>> - *
>> - * @dev:            parent device
>> - *
>> - * @base:            MMIO base
>> - *
>> - * @core_clk:            controller clock
>> - * @aon_clk:            another controller clock
>> - *
>> - * @regs:            a contiguous chunk of memory for DMA register
>> - *                writes. contains the register values to be
>> - *                written to controller
>> - *
>> - * @props:            properties of current NAND controller,
>> - *                initialized via DT match data
>> - *
>> - * @controller:            base controller structure
>> - * @host_list:            list containing all the chips attached to the
>> - *                controller
>> - *
>> - * @chan:            dma channel
>> - * @cmd_crci:            ADM DMA CRCI for command flow control
>> - * @data_crci:            ADM DMA CRCI for data flow control
>> - *
>> - * @desc_list:            DMA descriptor list (list of desc_infos)
>> - *
>> - * @data_buffer:        our local DMA buffer for page read/writes,
>> - *                used when we can't use the buffer provided
>> - *                by upper layers directly
>> - * @reg_read_buf:        local buffer for reading back registers via DMA
>> - *
>> - * @base_phys:            physical base address of controller registers
>> - * @base_dma:            dma base address of controller registers
>> - * @reg_read_dma:        contains dma address for register read buffer
>> - *
>> - * @buf_size/count/start:    markers for chip->legacy.read_buf/write_buf
>> - *                functions
>> - * @max_cwperpage:        maximum QPIC codewords required. calculated
>> - *                from all connected NAND devices pagesize
>> - *
>> - * @reg_read_pos:        marker for data read in reg_read_buf
>> - *
>> - * @cmd1/vld:            some fixed controller register values
>> - *
>> - * @exec_opwrite:        flag to select correct number of code word
>> - *                while reading status
>> - */
>> -struct qcom_nand_controller {
>> -    struct device *dev;
>> -
>> -    void __iomem *base;
>> -
>> -    struct clk *core_clk;
>> -    struct clk *aon_clk;
>> -
>> -    struct nandc_regs *regs;
>> -    struct bam_transaction *bam_txn;
>> -
>> -    const struct qcom_nandc_props *props;
>> -
>> -    struct nand_controller controller;
>> -    struct list_head host_list;
>> -
>> -    union {
>> -        /* will be used only by QPIC for BAM DMA */
>> -        struct {
>> -            struct dma_chan *tx_chan;
>> -            struct dma_chan *rx_chan;
>> -            struct dma_chan *cmd_chan;
>> -        };
>> -
>> -        /* will be used only by EBI2 for ADM DMA */
>> -        struct {
>> -            struct dma_chan *chan;
>> -            unsigned int cmd_crci;
>> -            unsigned int data_crci;
>> -        };
>> -    };
>> -
>> -    struct list_head desc_list;
>> -
>> -    u8        *data_buffer;
>> -    __le32        *reg_read_buf;
>> -
>> -    phys_addr_t base_phys;
>> -    dma_addr_t base_dma;
>> -    dma_addr_t reg_read_dma;
>> -
>> -    int        buf_size;
>> -    int        buf_count;
>> -    int        buf_start;
>> -    unsigned int    max_cwperpage;
>> -
>> -    int reg_read_pos;
>> -
>> -    u32 cmd1, vld;
>> -    bool exec_opwrite;
>> -};
>> -
>>   /*
>>    * NAND special boot partitions
>>    *
>> @@ -544,113 +124,17 @@ struct qcom_nand_host {
>>       bool bch_enabled;
>>   };
>> -/*
>> - * This data type corresponds to the NAND controller properties which varies
>> - * among different NAND controllers.
>> - * @ecc_modes - ecc mode for NAND
>> - * @dev_cmd_reg_start - NAND_DEV_CMD_* registers starting offset
>> - * @is_bam - whether NAND controller is using BAM
>> - * @is_qpic - whether NAND CTRL is part of qpic IP
>> - * @qpic_v2 - flag to indicate QPIC IP version 2
>> - * @use_codeword_fixup - whether NAND has different layout for boot partitions
>> - */
>> -struct qcom_nandc_props {
>> -    u32 ecc_modes;
>> -    u32 dev_cmd_reg_start;
>> -    bool is_bam;
>> -    bool is_qpic;
>> -    bool qpic_v2;
>> -    bool use_codeword_fixup;
>> -};
>> -
>> -/* Frees the BAM transaction memory */
>> -static void free_bam_transaction(struct qcom_nand_controller *nandc)
>> -{
>> -    struct bam_transaction *bam_txn = nandc->bam_txn;
>> -
>> -    devm_kfree(nandc->dev, bam_txn);
>> -}
>> -
>> -/* Allocates and Initializes the BAM transaction */
>> -static struct bam_transaction *
>> -alloc_bam_transaction(struct qcom_nand_controller *nandc)
>> -{
>> -    struct bam_transaction *bam_txn;
>> -    size_t bam_txn_size;
>> -    unsigned int num_cw = nandc->max_cwperpage;
>> -    void *bam_txn_buf;
>> -
>> -    bam_txn_size =
>> -        sizeof(*bam_txn) + num_cw *
>> -        ((sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS) +
>> -        (sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL) +
>> -        (sizeof(*bam_txn->data_sgl) * QPIC_PER_CW_DATA_SGL));
>> -
>> -    bam_txn_buf = devm_kzalloc(nandc->dev, bam_txn_size, GFP_KERNEL);
>> -    if (!bam_txn_buf)
>> -        return NULL;
>> -
>> -    bam_txn = bam_txn_buf;
>> -    bam_txn_buf += sizeof(*bam_txn);
>> -
>> -    bam_txn->bam_ce = bam_txn_buf;
>> -    bam_txn_buf +=
>> -        sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS * num_cw;
>> -
>> -    bam_txn->cmd_sgl = bam_txn_buf;
>> -    bam_txn_buf +=
>> -        sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL * num_cw;
>> -
>> -    bam_txn->data_sgl = bam_txn_buf;
>> -
>> -    init_completion(&bam_txn->txn_done);
>> -
>> -    return bam_txn;
>> -}
>> -
>> -/* Clears the BAM transaction indexes */
>> -static void clear_bam_transaction(struct qcom_nand_controller *nandc)
>> +static void nandc_set_reg(struct nand_chip *chip, int offset,
>> +              u32 val)
>>   {
>> -    struct bam_transaction *bam_txn = nandc->bam_txn;
>> -
>> -    if (!nandc->props->is_bam)
>> -        return;
>> -
>> -    bam_txn->bam_ce_pos = 0;
>> -    bam_txn->bam_ce_start = 0;
>> -    bam_txn->cmd_sgl_pos = 0;
>> -    bam_txn->cmd_sgl_start = 0;
>> -    bam_txn->tx_sgl_pos = 0;
>> -    bam_txn->tx_sgl_start = 0;
>> -    bam_txn->rx_sgl_pos = 0;
>> -    bam_txn->rx_sgl_start = 0;
>> -    bam_txn->last_data_desc = NULL;
>> -    bam_txn->wait_second_completion = false;
>> -
>> -    sg_init_table(bam_txn->cmd_sgl, nandc->max_cwperpage *
>> -              QPIC_PER_CW_CMD_SGL);
>> -    sg_init_table(bam_txn->data_sgl, nandc->max_cwperpage *
>> -              QPIC_PER_CW_DATA_SGL);
>> -
>> -    reinit_completion(&bam_txn->txn_done);
>> -}
>> +    struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
>> +    struct nandc_regs *regs = nandc->regs;
>> +    __le32 *reg;
>> -/* Callback for DMA descriptor completion */
>> -static void qpic_bam_dma_done(void *data)
>> -{
>> -    struct bam_transaction *bam_txn = data;
>> +    reg = offset_to_nandc_reg(regs, offset);
>> -    /*
>> -     * In case of data transfer with NAND, 2 callbacks will be generated.
>> -     * One for command channel and another one for data channel.
>> -     * If current transaction has data descriptors
>> -     * (i.e. wait_second_completion is true), then set this to false
>> -     * and wait for second DMA descriptor completion.
>> -     */
>> -    if (bam_txn->wait_second_completion)
>> -        bam_txn->wait_second_completion = false;
>> -    else
>> -        complete(&bam_txn->txn_done);
>> +    if (reg)
>> +        *reg = cpu_to_le32(val);
>>   }
>>   static inline struct qcom_nand_host *to_qcom_nand_host(struct nand_chip *chip)
>> @@ -658,13 +142,6 @@ static inline struct qcom_nand_host *to_qcom_nand_host(struct nand_chip *chip)
>>       return container_of(chip, struct qcom_nand_host, chip);
>>   }
>> -static inline struct qcom_nand_controller *
>> -get_qcom_nand_controller(struct nand_chip *chip)
>> -{
>> -    return container_of(chip->controller, struct qcom_nand_controller,
>> -                controller);
>> -}
>> -
>>   static inline u32 nandc_read(struct qcom_nand_controller *nandc, int offset)
>>   {
>>       return ioread32(nandc->base + offset);
>> @@ -676,91 +153,6 @@ static inline void nandc_write(struct qcom_nand_controller *nandc, int offset,
>>       iowrite32(val, nandc->base + offset);
>>   }
>> -static inline void nandc_read_buffer_sync(struct qcom_nand_controller *nandc,
>> -                      bool is_cpu)
>> -{
>> -    if (!nandc->props->is_bam)
>> -        return;
>> -
>> -    if (is_cpu)
>> -        dma_sync_single_for_cpu(nandc->dev, nandc->reg_read_dma,
>> -                    MAX_REG_RD *
>> -                    sizeof(*nandc->reg_read_buf),
>> -                    DMA_FROM_DEVICE);
>> -    else
>> -        dma_sync_single_for_device(nandc->dev, nandc->reg_read_dma,
>> -                       MAX_REG_RD *
>> -                       sizeof(*nandc->reg_read_buf),
>> -                       DMA_FROM_DEVICE);
>> -}
>> -
>> -static __le32 *offset_to_nandc_reg(struct nandc_regs *regs, int offset)
>> -{
>> -    switch (offset) {
>> -    case NAND_FLASH_CMD:
>> -        return &regs->cmd;
>> -    case NAND_ADDR0:
>> -        return &regs->addr0;
>> -    case NAND_ADDR1:
>> -        return &regs->addr1;
>> -    case NAND_FLASH_CHIP_SELECT:
>> -        return &regs->chip_sel;
>> -    case NAND_EXEC_CMD:
>> -        return &regs->exec;
>> -    case NAND_FLASH_STATUS:
>> -        return &regs->clrflashstatus;
>> -    case NAND_DEV0_CFG0:
>> -        return &regs->cfg0;
>> -    case NAND_DEV0_CFG1:
>> -        return &regs->cfg1;
>> -    case NAND_DEV0_ECC_CFG:
>> -        return &regs->ecc_bch_cfg;
>> -    case NAND_READ_STATUS:
>> -        return &regs->clrreadstatus;
>> -    case NAND_DEV_CMD1:
>> -        return &regs->cmd1;
>> -    case NAND_DEV_CMD1_RESTORE:
>> -        return &regs->orig_cmd1;
>> -    case NAND_DEV_CMD_VLD:
>> -        return &regs->vld;
>> -    case NAND_DEV_CMD_VLD_RESTORE:
>> -        return &regs->orig_vld;
>> -    case NAND_EBI2_ECC_BUF_CFG:
>> -        return &regs->ecc_buf_cfg;
>> -    case NAND_READ_LOCATION_0:
>> -        return &regs->read_location0;
>> -    case NAND_READ_LOCATION_1:
>> -        return &regs->read_location1;
>> -    case NAND_READ_LOCATION_2:
>> -        return &regs->read_location2;
>> -    case NAND_READ_LOCATION_3:
>> -        return &regs->read_location3;
>> -    case NAND_READ_LOCATION_LAST_CW_0:
>> -        return &regs->read_location_last0;
>> -    case NAND_READ_LOCATION_LAST_CW_1:
>> -        return &regs->read_location_last1;
>> -    case NAND_READ_LOCATION_LAST_CW_2:
>> -        return &regs->read_location_last2;
>> -    case NAND_READ_LOCATION_LAST_CW_3:
>> -        return &regs->read_location_last3;
>> -    default:
>> -        return NULL;
>> -    }
>> -}
>> -
>> -static void nandc_set_reg(struct nand_chip *chip, int offset,
>> -              u32 val)
>> -{
>> -    struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
>> -    struct nandc_regs *regs = nandc->regs;
>> -    __le32 *reg;
>> -
>> -    reg = offset_to_nandc_reg(regs, offset);
>> -
>> -    if (reg)
>> -        *reg = cpu_to_le32(val);
>> -}
>> -
>>   /* Helper to check the code word, whether it is last cw or not */
>>   static bool qcom_nandc_is_last_cw(struct nand_ecc_ctrl *ecc, int cw)
>>   {
>> @@ -852,383 +244,6 @@ static void update_rw_regs(struct qcom_nand_host *host, int num_cw, bool read, i
>>                      host->cw_data : host->cw_size, 1);
>>   }
>> -/*
>> - * Maps the scatter gather list for DMA transfer and forms the DMA descriptor
>> - * for BAM. This descriptor will be added in the NAND DMA descriptor queue
>> - * which will be submitted to DMA engine.
>> - */
>> -static int prepare_bam_async_desc(struct qcom_nand_controller *nandc,
>> -                  struct dma_chan *chan,
>> -                  unsigned long flags)
>> -{
>> -    struct desc_info *desc;
>> -    struct scatterlist *sgl;
>> -    unsigned int sgl_cnt;
>> -    int ret;
>> -    struct bam_transaction *bam_txn = nandc->bam_txn;
>> -    enum dma_transfer_direction dir_eng;
>> -    struct dma_async_tx_descriptor *dma_desc;
>> -
>> -    desc = kzalloc(sizeof(*desc), GFP_KERNEL);
>> -    if (!desc)
>> -        return -ENOMEM;
>> -
>> -    if (chan == nandc->cmd_chan) {
>> -        sgl = &bam_txn->cmd_sgl[bam_txn->cmd_sgl_start];
>> -        sgl_cnt = bam_txn->cmd_sgl_pos - bam_txn->cmd_sgl_start;
>> -        bam_txn->cmd_sgl_start = bam_txn->cmd_sgl_pos;
>> -        dir_eng = DMA_MEM_TO_DEV;
>> -        desc->dir = DMA_TO_DEVICE;
>> -    } else if (chan == nandc->tx_chan) {
>> -        sgl = &bam_txn->data_sgl[bam_txn->tx_sgl_start];
>> -        sgl_cnt = bam_txn->tx_sgl_pos - bam_txn->tx_sgl_start;
>> -        bam_txn->tx_sgl_start = bam_txn->tx_sgl_pos;
>> -        dir_eng = DMA_MEM_TO_DEV;
>> -        desc->dir = DMA_TO_DEVICE;
>> -    } else {
>> -        sgl = &bam_txn->data_sgl[bam_txn->rx_sgl_start];
>> -        sgl_cnt = bam_txn->rx_sgl_pos - bam_txn->rx_sgl_start;
>> -        bam_txn->rx_sgl_start = bam_txn->rx_sgl_pos;
>> -        dir_eng = DMA_DEV_TO_MEM;
>> -        desc->dir = DMA_FROM_DEVICE;
>> -    }
>> -
>> -    sg_mark_end(sgl + sgl_cnt - 1);
>> -    ret = dma_map_sg(nandc->dev, sgl, sgl_cnt, desc->dir);
>> -    if (ret == 0) {
>> -        dev_err(nandc->dev, "failure in mapping desc\n");
>> -        kfree(desc);
>> -        return -ENOMEM;
>> -    }
>> -
>> -    desc->sgl_cnt = sgl_cnt;
>> -    desc->bam_sgl = sgl;
>> -
>> -    dma_desc = dmaengine_prep_slave_sg(chan, sgl, sgl_cnt, dir_eng,
>> -                       flags);
>> -
>> -    if (!dma_desc) {
>> -        dev_err(nandc->dev, "failure in prep desc\n");
>> -        dma_unmap_sg(nandc->dev, sgl, sgl_cnt, desc->dir);
>> -        kfree(desc);
>> -        return -EINVAL;
>> -    }
>> -
>> -    desc->dma_desc = dma_desc;
>> -
>> -    /* update last data/command descriptor */
>> -    if (chan == nandc->cmd_chan)
>> -        bam_txn->last_cmd_desc = dma_desc;
>> -    else
>> -        bam_txn->last_data_desc = dma_desc;
>> -
>> -    list_add_tail(&desc->node, &nandc->desc_list);
>> -
>> -    return 0;
>> -}
>> -
>> -/*
>> - * Prepares the command descriptor for BAM DMA which will be used for NAND
>> - * register reads and writes. The command descriptor requires the command
>> - * to be formed in command element type so this function uses the command
>> - * element from bam transaction ce array and fills the same with required
>> - * data. A single SGL can contain multiple command elements so
>> - * NAND_BAM_NEXT_SGL will be used for starting the separate SGL
>> - * after the current command element.
>> - */
>> -static int prep_bam_dma_desc_cmd(struct qcom_nand_controller *nandc, bool read,
>> -                 int reg_off, const void *vaddr,
>> -                 int size, unsigned int flags)
>> -{
>> -    int bam_ce_size;
>> -    int i, ret;
>> -    struct bam_cmd_element *bam_ce_buffer;
>> -    struct bam_transaction *bam_txn = nandc->bam_txn;
>> -
>> -    bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_pos];
>> -
>> -    /* fill the command desc */
>> -    for (i = 0; i < size; i++) {
>> -        if (read)
>> -            bam_prep_ce(&bam_ce_buffer[i],
>> -                    nandc_reg_phys(nandc, reg_off + 4 * i),
>> -                    BAM_READ_COMMAND,
>> -                    reg_buf_dma_addr(nandc,
>> -                             (__le32 *)vaddr + i));
>> -        else
>> -            bam_prep_ce_le32(&bam_ce_buffer[i],
>> -                     nandc_reg_phys(nandc, reg_off + 4 * i),
>> -                     BAM_WRITE_COMMAND,
>> -                     *((__le32 *)vaddr + i));
>> -    }
>> -
>> -    bam_txn->bam_ce_pos += size;
>> -
>> -    /* use the separate sgl after this command */
>> -    if (flags & NAND_BAM_NEXT_SGL) {
>> -        bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_start];
>> -        bam_ce_size = (bam_txn->bam_ce_pos -
>> -                bam_txn->bam_ce_start) *
>> -                sizeof(struct bam_cmd_element);
>> -        sg_set_buf(&bam_txn->cmd_sgl[bam_txn->cmd_sgl_pos],
>> -               bam_ce_buffer, bam_ce_size);
>> -        bam_txn->cmd_sgl_pos++;
>> -        bam_txn->bam_ce_start = bam_txn->bam_ce_pos;
>> -
>> -        if (flags & NAND_BAM_NWD) {
>> -            ret = prepare_bam_async_desc(nandc, nandc->cmd_chan,
>> -                             DMA_PREP_FENCE |
>> -                             DMA_PREP_CMD);
>> -            if (ret)
>> -                return ret;
>> -        }
>> -    }
>> -
>> -    return 0;
>> -}
>> -
>> -/*
>> - * Prepares the data descriptor for BAM DMA which will be used for NAND
>> - * data reads and writes.
>> - */
>> -static int prep_bam_dma_desc_data(struct qcom_nand_controller *nandc, bool read,
>> -                  const void *vaddr,
>> -                  int size, unsigned int flags)
>> -{
>> -    int ret;
>> -    struct bam_transaction *bam_txn = nandc->bam_txn;
>> -
>> -    if (read) {
>> -        sg_set_buf(&bam_txn->data_sgl[bam_txn->rx_sgl_pos],
>> -               vaddr, size);
>> -        bam_txn->rx_sgl_pos++;
>> -    } else {
>> -        sg_set_buf(&bam_txn->data_sgl[bam_txn->tx_sgl_pos],
>> -               vaddr, size);
>> -        bam_txn->tx_sgl_pos++;
>> -
>> -        /*
>> -         * BAM will only set EOT for DMA_PREP_INTERRUPT so if this flag
>> -         * is not set, form the DMA descriptor
>> -         */
>> -        if (!(flags & NAND_BAM_NO_EOT)) {
>> -            ret = prepare_bam_async_desc(nandc, nandc->tx_chan,
>> -                             DMA_PREP_INTERRUPT);
>> -            if (ret)
>> -                return ret;
>> -        }
>> -    }
>> -
>> -    return 0;
>> -}
>> -
>> -static int prep_adm_dma_desc(struct qcom_nand_controller *nandc, bool read,
>> -                 int reg_off, const void *vaddr, int size,
>> -                 bool flow_control)
>> -{
>> -    struct desc_info *desc;
>> -    struct dma_async_tx_descriptor *dma_desc;
>> -    struct scatterlist *sgl;
>> -    struct dma_slave_config slave_conf;
>> -    struct qcom_adm_peripheral_config periph_conf = {};
>> -    enum dma_transfer_direction dir_eng;
>> -    int ret;
>> -
>> -    desc = kzalloc(sizeof(*desc), GFP_KERNEL);
>> -    if (!desc)
>> -        return -ENOMEM;
>> -
>> -    sgl = &desc->adm_sgl;
>> -
>> -    sg_init_one(sgl, vaddr, size);
>> -
>> -    if (read) {
>> -        dir_eng = DMA_DEV_TO_MEM;
>> -        desc->dir = DMA_FROM_DEVICE;
>> -    } else {
>> -        dir_eng = DMA_MEM_TO_DEV;
>> -        desc->dir = DMA_TO_DEVICE;
>> -    }
>> -
>> -    ret = dma_map_sg(nandc->dev, sgl, 1, desc->dir);
>> -    if (ret == 0) {
>> -        ret = -ENOMEM;
>> -        goto err;
>> -    }
>> -
>> -    memset(&slave_conf, 0x00, sizeof(slave_conf));
>> -
>> -    slave_conf.device_fc = flow_control;
>> -    if (read) {
>> -        slave_conf.src_maxburst = 16;
>> -        slave_conf.src_addr = nandc->base_dma + reg_off;
>> -        if (nandc->data_crci) {
>> -            periph_conf.crci = nandc->data_crci;
>> -            slave_conf.peripheral_config = &periph_conf;
>> -            slave_conf.peripheral_size = sizeof(periph_conf);
>> -        }
>> -    } else {
>> -        slave_conf.dst_maxburst = 16;
>> -        slave_conf.dst_addr = nandc->base_dma + reg_off;
>> -        if (nandc->cmd_crci) {
>> -            periph_conf.crci = nandc->cmd_crci;
>> -            slave_conf.peripheral_config = &periph_conf;
>> -            slave_conf.peripheral_size = sizeof(periph_conf);
>> -        }
>> -    }
>> -
>> -    ret = dmaengine_slave_config(nandc->chan, &slave_conf);
>> -    if (ret) {
>> -        dev_err(nandc->dev, "failed to configure dma channel\n");
>> -        goto err;
>> -    }
>> -
>> -    dma_desc = dmaengine_prep_slave_sg(nandc->chan, sgl, 1, dir_eng, 0);
>> -    if (!dma_desc) {
>> -        dev_err(nandc->dev, "failed to prepare desc\n");
>> -        ret = -EINVAL;
>> -        goto err;
>> -    }
>> -
>> -    desc->dma_desc = dma_desc;
>> -
>> -    list_add_tail(&desc->node, &nandc->desc_list);
>> -
>> -    return 0;
>> -err:
>> -    kfree(desc);
>> -
>> -    return ret;
>> -}
>> -
>> -/*
>> - * read_reg_dma:    prepares a descriptor to read a given number of
>> - *            contiguous registers to the reg_read_buf pointer
>> - *
>> - * @first:        offset of the first register in the contiguous block
>> - * @num_regs:        number of registers to read
>> - * @flags:        flags to control DMA descriptor preparation
>> - */
>> -static int read_reg_dma(struct qcom_nand_controller *nandc, int first,
>> -            int num_regs, unsigned int flags)
>> -{
>> -    bool flow_control = false;
>> -    void *vaddr;
>> -
>> -    vaddr = nandc->reg_read_buf + nandc->reg_read_pos;
>> -    nandc->reg_read_pos += num_regs;
>> -
>> -    if (first == NAND_DEV_CMD_VLD || first == NAND_DEV_CMD1)
>> -        first = dev_cmd_reg_addr(nandc, first);
>> -
>> -    if (nandc->props->is_bam)
>> -        return prep_bam_dma_desc_cmd(nandc, true, first, vaddr,
>> -                         num_regs, flags);
>> -
>> -    if (first == NAND_READ_ID || first == NAND_FLASH_STATUS)
>> -        flow_control = true;
>> -
>> -    return prep_adm_dma_desc(nandc, true, first, vaddr,
>> -                 num_regs * sizeof(u32), flow_control);
>> -}
>> -
>> -/*
>> - * write_reg_dma:    prepares a descriptor to write a given number of
>> - *            contiguous registers
>> - *
>> - * @first:        offset of the first register in the contiguous block
>> - * @num_regs:        number of registers to write
>> - * @flags:        flags to control DMA descriptor preparation
>> - */
>> -static int write_reg_dma(struct qcom_nand_controller *nandc, int first,
>> -             int num_regs, unsigned int flags)
>> -{
>> -    bool flow_control = false;
>> -    struct nandc_regs *regs = nandc->regs;
>> -    void *vaddr;
>> -
>> -    vaddr = offset_to_nandc_reg(regs, first);
>> -
>> -    if (first == NAND_ERASED_CW_DETECT_CFG) {
>> -        if (flags & NAND_ERASED_CW_SET)
>> -            vaddr = &regs->erased_cw_detect_cfg_set;
>> -        else
>> -            vaddr = &regs->erased_cw_detect_cfg_clr;
>> -    }
>> -
>> -    if (first == NAND_EXEC_CMD)
>> -        flags |= NAND_BAM_NWD;
>> -
>> -    if (first == NAND_DEV_CMD1_RESTORE || first == NAND_DEV_CMD1)
>> -        first = dev_cmd_reg_addr(nandc, NAND_DEV_CMD1);
>> -
>> -    if (first == NAND_DEV_CMD_VLD_RESTORE || first == NAND_DEV_CMD_VLD)
>> -        first = dev_cmd_reg_addr(nandc, NAND_DEV_CMD_VLD);
>> -
>> -    if (nandc->props->is_bam)
>> -        return prep_bam_dma_desc_cmd(nandc, false, first, vaddr,
>> -                         num_regs, flags);
>> -
>> -    if (first == NAND_FLASH_CMD)
>> -        flow_control = true;
>> -
>> -    return prep_adm_dma_desc(nandc, false, first, vaddr,
>> -                 num_regs * sizeof(u32), flow_control);
>> -}
>> -
>> -/*
>> - * read_data_dma:    prepares a DMA descriptor to transfer data from the
>> - *            controller's internal buffer to the buffer 'vaddr'
>> - *
>> - * @reg_off:        offset within the controller's data buffer
>> - * @vaddr:        virtual address of the buffer we want to write to
>> - * @size:        DMA transaction size in bytes
>> - * @flags:        flags to control DMA descriptor preparation
>> - */
>> -static int read_data_dma(struct qcom_nand_controller *nandc, int reg_off,
>> -             const u8 *vaddr, int size, unsigned int flags)
>> -{
>> -    if (nandc->props->is_bam)
>> -        return prep_bam_dma_desc_data(nandc, true, vaddr, size, flags);
>> -
>> -    return prep_adm_dma_desc(nandc, true, reg_off, vaddr, size, false);
>> -}
>> -
>> -/*
>> - * write_data_dma:    prepares a DMA descriptor to transfer data from
>> - *            'vaddr' to the controller's internal buffer
>> - *
>> - * @reg_off:        offset within the controller's data buffer
>> - * @vaddr:        virtual address of the buffer we want to read from
>> - * @size:        DMA transaction size in bytes
>> - * @flags:        flags to control DMA descriptor preparation
>> - */
>> -static int write_data_dma(struct qcom_nand_controller *nandc, int reg_off,
>> -              const u8 *vaddr, int size, unsigned int flags)
>> -{
>> -    if (nandc->props->is_bam)
>> -        return prep_bam_dma_desc_data(nandc, false, vaddr, size, flags);
>> -
>> -    return prep_adm_dma_desc(nandc, false, reg_off, vaddr, size, false);
>> -}
>> -
>> -/*
>> - * Helper to prepare DMA descriptors for configuring registers
>> - * before reading a NAND page.
>> - */
>> -static void config_nand_page_read(struct nand_chip *chip)
>> -{
>> -    struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
>> -
>> -    write_reg_dma(nandc, NAND_ADDR0, 2, 0);
>> -    write_reg_dma(nandc, NAND_DEV0_CFG0, 3, 0);
>> -    if (!nandc->props->qpic_v2)
>> -        write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1, 0);
>> -    write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1, 0);
>> -    write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1,
>> -              NAND_ERASED_CW_SET | NAND_BAM_NEXT_SGL);
>> -}
>> -
>>   /*
>>    * Helper to prepare DMA descriptors for configuring registers
>>    * before reading each codeword in NAND page.
>> @@ -1303,88 +318,6 @@ static void config_nand_cw_write(struct nand_chip *chip)
>>       write_reg_dma(nandc, NAND_READ_STATUS, 1, NAND_BAM_NEXT_SGL);
>>   }
>> -/* helpers to submit/free our list of dma descriptors */
>> -static int submit_descs(struct qcom_nand_controller *nandc)
>> -{
>> -    struct desc_info *desc, *n;
>> -    dma_cookie_t cookie = 0;
>> -    struct bam_transaction *bam_txn = nandc->bam_txn;
>> -    int ret = 0;
>> -
>> -    if (nandc->props->is_bam) {
>> -        if (bam_txn->rx_sgl_pos > bam_txn->rx_sgl_start) {
>> -            ret = prepare_bam_async_desc(nandc, nandc->rx_chan, 0);
>> -            if (ret)
>> -                goto err_unmap_free_desc;
>> -        }
>> -
>> -        if (bam_txn->tx_sgl_pos > bam_txn->tx_sgl_start) {
>> -            ret = prepare_bam_async_desc(nandc, nandc->tx_chan,
>> -                           DMA_PREP_INTERRUPT);
>> -            if (ret)
>> -                goto err_unmap_free_desc;
>> -        }
>> -
>> -        if (bam_txn->cmd_sgl_pos > bam_txn->cmd_sgl_start) {
>> -            ret = prepare_bam_async_desc(nandc, nandc->cmd_chan,
>> -                           DMA_PREP_CMD);
>> -            if (ret)
>> -                goto err_unmap_free_desc;
>> -        }
>> -    }
>> -
>> -    list_for_each_entry(desc, &nandc->desc_list, node)
>> -        cookie = dmaengine_submit(desc->dma_desc);
>> -
>> -    if (nandc->props->is_bam) {
>> -        bam_txn->last_cmd_desc->callback = qpic_bam_dma_done;
>> -        bam_txn->last_cmd_desc->callback_param = bam_txn;
>> -        if (bam_txn->last_data_desc) {
>> -            bam_txn->last_data_desc->callback = qpic_bam_dma_done;
>> -            bam_txn->last_data_desc->callback_param = bam_txn;
>> -            bam_txn->wait_second_completion = true;
>> -        }
>> -
>> -        dma_async_issue_pending(nandc->tx_chan);
>> -        dma_async_issue_pending(nandc->rx_chan);
>> -        dma_async_issue_pending(nandc->cmd_chan);
>> -
>> -        if (!wait_for_completion_timeout(&bam_txn->txn_done,
>> -                         QPIC_NAND_COMPLETION_TIMEOUT))
>> -            ret = -ETIMEDOUT;
>> -    } else {
>> -        if (dma_sync_wait(nandc->chan, cookie) != DMA_COMPLETE)
>> -            ret = -ETIMEDOUT;
>> -    }
>> -
>> -err_unmap_free_desc:
>> -    /*
>> -     * Unmap the dma sg_list and free the desc allocated by both
>> -     * prepare_bam_async_desc() and prep_adm_dma_desc() functions.
>> -     */
>> -    list_for_each_entry_safe(desc, n, &nandc->desc_list, node) {
>> -        list_del(&desc->node);
>> -
>> -        if (nandc->props->is_bam)
>> -            dma_unmap_sg(nandc->dev, desc->bam_sgl,
>> -                     desc->sgl_cnt, desc->dir);
>> -        else
>> -            dma_unmap_sg(nandc->dev, &desc->adm_sgl, 1,
>> -                     desc->dir);
>> -
>> -        kfree(desc);
>> -    }
>> -
>> -    return ret;
>> -}
>> -
>> -/* reset the register read buffer for next NAND operation */
>> -static void clear_read_regs(struct qcom_nand_controller *nandc)
>> -{
>> -    nandc->reg_read_pos = 0;
>> -    nandc_read_buffer_sync(nandc, false);
>> -}
>> -
>>   /*
>>    * when using BCH ECC, the HW flags an error in NAND_FLASH_STATUS if it read
>>    * an erased CW, and reports an erased CW in NAND_ERASED_CW_DETECT_STATUS.
>> @@ -3016,136 +1949,6 @@ static const struct nand_controller_ops qcom_nandc_ops = {
>>       .exec_op = qcom_nand_exec_op,
>>   };
>> -static void qcom_nandc_unalloc(struct qcom_nand_controller *nandc)
>> -{
>> -    if (nandc->props->is_bam) {
>> -        if (!dma_mapping_error(nandc->dev, nandc->reg_read_dma))
>> -            dma_unmap_single(nandc->dev, nandc->reg_read_dma,
>> -                     MAX_REG_RD *
>> -                     sizeof(*nandc->reg_read_buf),
>> -                     DMA_FROM_DEVICE);
>> -
>> -        if (nandc->tx_chan)
>> -            dma_release_channel(nandc->tx_chan);
>> -
>> -        if (nandc->rx_chan)
>> -            dma_release_channel(nandc->rx_chan);
>> -
>> -        if (nandc->cmd_chan)
>> -            dma_release_channel(nandc->cmd_chan);
>> -    } else {
>> -        if (nandc->chan)
>> -            dma_release_channel(nandc->chan);
>> -    }
>> -}
>> -
>> -static int qcom_nandc_alloc(struct qcom_nand_controller *nandc)
>> -{
>> -    int ret;
>> -
>> -    ret = dma_set_coherent_mask(nandc->dev, DMA_BIT_MASK(32));
>> -    if (ret) {
>> -        dev_err(nandc->dev, "failed to set DMA mask\n");
>> -        return ret;
>> -    }
>> -
>> -    /*
>> -     * we use the internal buffer for reading ONFI params, reading small
>> -     * data like ID and status, and preforming read-copy-write operations
>> -     * when writing to a codeword partially. 532 is the maximum possible
>> -     * size of a codeword for our nand controller
>> -     */
>> -    nandc->buf_size = 532;
>> -
>> -    nandc->data_buffer = devm_kzalloc(nandc->dev, nandc->buf_size, GFP_KERNEL);
>> -    if (!nandc->data_buffer)
>> -        return -ENOMEM;
>> -
>> -    nandc->regs = devm_kzalloc(nandc->dev, sizeof(*nandc->regs), GFP_KERNEL);
>> -    if (!nandc->regs)
>> -        return -ENOMEM;
>> -
>> -    nandc->reg_read_buf = devm_kcalloc(nandc->dev, MAX_REG_RD,
>> -                       sizeof(*nandc->reg_read_buf),
>> -                       GFP_KERNEL);
>> -    if (!nandc->reg_read_buf)
>> -        return -ENOMEM;
>> -
>> -    if (nandc->props->is_bam) {
>> -        nandc->reg_read_dma =
>> -            dma_map_single(nandc->dev, nandc->reg_read_buf,
>> -                       MAX_REG_RD *
>> -                       sizeof(*nandc->reg_read_buf),
>> -                       DMA_FROM_DEVICE);
>> -        if (dma_mapping_error(nandc->dev, nandc->reg_read_dma)) {
>> -            dev_err(nandc->dev, "failed to DMA MAP reg buffer\n");
>> -            return -EIO;
>> -        }
>> -
>> -        nandc->tx_chan = dma_request_chan(nandc->dev, "tx");
>> -        if (IS_ERR(nandc->tx_chan)) {
>> -            ret = PTR_ERR(nandc->tx_chan);
>> -            nandc->tx_chan = NULL;
>> -            dev_err_probe(nandc->dev, ret,
>> -                      "tx DMA channel request failed\n");
>> -            goto unalloc;
>> -        }
>> -
>> -        nandc->rx_chan = dma_request_chan(nandc->dev, "rx");
>> -        if (IS_ERR(nandc->rx_chan)) {
>> -            ret = PTR_ERR(nandc->rx_chan);
>> -            nandc->rx_chan = NULL;
>> -            dev_err_probe(nandc->dev, ret,
>> -                      "rx DMA channel request failed\n");
>> -            goto unalloc;
>> -        }
>> -
>> -        nandc->cmd_chan = dma_request_chan(nandc->dev, "cmd");
>> -        if (IS_ERR(nandc->cmd_chan)) {
>> -            ret = PTR_ERR(nandc->cmd_chan);
>> -            nandc->cmd_chan = NULL;
>> -            dev_err_probe(nandc->dev, ret,
>> -                      "cmd DMA channel request failed\n");
>> -            goto unalloc;
>> -        }
>> -
>> -        /*
>> -         * Initially allocate BAM transaction to read ONFI param page.
>> -         * After detecting all the devices, this BAM transaction will
>> -         * be freed and the next BAM transaction will be allocated with
>> -         * maximum codeword size
>> -         */
>> -        nandc->max_cwperpage = 1;
>> -        nandc->bam_txn = alloc_bam_transaction(nandc);
>> -        if (!nandc->bam_txn) {
>> -            dev_err(nandc->dev,
>> -                "failed to allocate bam transaction\n");
>> -            ret = -ENOMEM;
>> -            goto unalloc;
>> -        }
>> -    } else {
>> -        nandc->chan = dma_request_chan(nandc->dev, "rxtx");
>> -        if (IS_ERR(nandc->chan)) {
>> -            ret = PTR_ERR(nandc->chan);
>> -            nandc->chan = NULL;
>> -            dev_err_probe(nandc->dev, ret,
>> -                      "rxtx DMA channel request failed\n");
>> -            return ret;
>> -        }
>> -    }
>> -
>> -    INIT_LIST_HEAD(&nandc->desc_list);
>> -    INIT_LIST_HEAD(&nandc->host_list);
>> -
>> -    nand_controller_init(&nandc->controller);
>> -    nandc->controller.ops = &qcom_nandc_ops;
>> -
>> -    return 0;
>> -unalloc:
>> -    qcom_nandc_unalloc(nandc);
>> -    return ret;
>> -}
>> -
>>   /* one time setup of a few nand controller registers */
>>   static int qcom_nandc_setup(struct qcom_nand_controller *nandc)
>>   {
>> @@ -3427,6 +2230,9 @@ static int qcom_nandc_probe(struct platform_device *pdev)
>>       if (ret)
>>           goto err_nandc_alloc;
>> +    nand_controller_init(&nandc->controller);
>> +    nandc->controller.ops = &qcom_nandc_ops;
>> +
>>       ret = qcom_nandc_setup(nandc);
>>       if (ret)
>>           goto err_setup;
>> @@ -3473,28 +2279,28 @@ static void qcom_nandc_remove(struct platform_device *pdev)
>>                  DMA_BIDIRECTIONAL, 0);
>>   }
>> -static const struct qcom_nandc_props ipq806x_nandc_props = {
>> +static struct qcom_nandc_props ipq806x_nandc_props = {
>>       .ecc_modes = (ECC_RS_4BIT | ECC_BCH_8BIT),
>>       .is_bam = false,
>>       .use_codeword_fixup = true,
>>       .dev_cmd_reg_start = 0x0,
>>   };
>> -static const struct qcom_nandc_props ipq4019_nandc_props = {
>> +static struct qcom_nandc_props ipq4019_nandc_props = {
>>       .ecc_modes = (ECC_BCH_4BIT | ECC_BCH_8BIT),
>>       .is_bam = true,
>>       .is_qpic = true,
>>       .dev_cmd_reg_start = 0x0,
>>   };
>> -static const struct qcom_nandc_props ipq8074_nandc_props = {
>> +static struct qcom_nandc_props ipq8074_nandc_props = {
>>       .ecc_modes = (ECC_BCH_4BIT | ECC_BCH_8BIT),
>>       .is_bam = true,
>>       .is_qpic = true,
>>       .dev_cmd_reg_start = 0x7000,
>>   };
>> -static const struct qcom_nandc_props sdx55_nandc_props = {
>> +static struct qcom_nandc_props sdx55_nandc_props = {
>>       .ecc_modes = (ECC_BCH_4BIT | ECC_BCH_8BIT),
>>       .is_bam = true,
>>       .is_qpic = true,
>> diff --git a/include/linux/mtd/nand-qpic-common.h b/include/linux/mtd/nand-qpic-common.h
>> new file mode 100644
>> index 000000000000..891f975ca173
>> --- /dev/null
>> +++ b/include/linux/mtd/nand-qpic-common.h
>> @@ -0,0 +1,488 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/*
>> + * QCOM QPIC common APIs header file
>> + *
>> + * Copyright (c) 2023 Qualcomm Inc.
>> + * Authors:     Md sadre Alam           <quic_mdalam@quicinc.com>
>> + *        Sricharan R             <quic_srichara@quicinc.com>
>> + *        Varadarajan Narayanan   <quic_varada@quicinc.com>
>> + *
>> + */
>> +#ifndef __MTD_NAND_QPIC_COMMON_H__
>> +#define __MTD_NAND_QPIC_COMMON_H__
>> +
>> +#include <linux/bitops.h>
>> +#include <linux/clk.h>
>> +#include <linux/delay.h>
>> +#include <linux/dmaengine.h>
>> +#include <linux/dma-mapping.h>
>> +#include <linux/dma/qcom_adm.h>
>> +#include <linux/dma/qcom_bam_dma.h>
>> +#include <linux/module.h>
>> +#include <linux/mtd/partitions.h>
>> +#include <linux/mtd/rawnand.h>
>> +#include <linux/of.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/slab.h>
>> +
>> +/* NANDc reg offsets */
>> +#define    NAND_FLASH_CMD            0x00
>> +#define    NAND_ADDR0            0x04
>> +#define    NAND_ADDR1            0x08
>> +#define    NAND_FLASH_CHIP_SELECT        0x0c
>> +#define    NAND_EXEC_CMD            0x10
>> +#define    NAND_FLASH_STATUS        0x14
>> +#define    NAND_BUFFER_STATUS        0x18
>> +#define    NAND_DEV0_CFG0            0x20
>> +#define    NAND_DEV0_CFG1            0x24
>> +#define    NAND_DEV0_ECC_CFG        0x28
>> +#define    NAND_AUTO_STATUS_EN        0x2c
>> +#define    NAND_DEV1_CFG0            0x30
>> +#define    NAND_DEV1_CFG1            0x34
>> +#define    NAND_READ_ID            0x40
>> +#define    NAND_READ_STATUS        0x44
>> +#define    NAND_DEV_CMD0            0xa0
>> +#define    NAND_DEV_CMD1            0xa4
>> +#define    NAND_DEV_CMD2            0xa8
>> +#define    NAND_DEV_CMD_VLD        0xac
>> +#define    SFLASHC_BURST_CFG        0xe0
>> +#define    NAND_ERASED_CW_DETECT_CFG    0xe8
>> +#define    NAND_ERASED_CW_DETECT_STATUS    0xec
>> +#define    NAND_EBI2_ECC_BUF_CFG        0xf0
>> +#define    FLASH_BUF_ACC            0x100
>> +
>> +#define    NAND_CTRL            0xf00
>> +#define    NAND_VERSION            0xf08
>> +#define    NAND_READ_LOCATION_0        0xf20
>> +#define    NAND_READ_LOCATION_1        0xf24
>> +#define    NAND_READ_LOCATION_2        0xf28
>> +#define    NAND_READ_LOCATION_3        0xf2c
>> +#define    NAND_READ_LOCATION_LAST_CW_0    0xf40
>> +#define    NAND_READ_LOCATION_LAST_CW_1    0xf44
>> +#define    NAND_READ_LOCATION_LAST_CW_2    0xf48
>> +#define    NAND_READ_LOCATION_LAST_CW_3    0xf4c
>> +
>> +/* dummy register offsets, used by write_reg_dma */
>> +#define    NAND_DEV_CMD1_RESTORE        0xdead
>> +#define    NAND_DEV_CMD_VLD_RESTORE    0xbeef
>> +
>> +/* NAND_FLASH_CMD bits */
>> +#define    PAGE_ACC            BIT(4)
>> +#define    LAST_PAGE            BIT(5)
>> +
>> +/* NAND_FLASH_CHIP_SELECT bits */
>> +#define    NAND_DEV_SEL            0
>> +#define    DM_EN                BIT(2)
>> +
>> +/* NAND_FLASH_STATUS bits */
>> +#define    FS_OP_ERR            BIT(4)
>> +#define    FS_READY_BSY_N            BIT(5)
>> +#define    FS_MPU_ERR            BIT(8)
>> +#define    FS_DEVICE_STS_ERR        BIT(16)
>> +#define    FS_DEVICE_WP            BIT(23)
>> +
>> +/* NAND_BUFFER_STATUS bits */
>> +#define    BS_UNCORRECTABLE_BIT        BIT(8)
>> +#define    BS_CORRECTABLE_ERR_MSK        0x1f
>> +
>> +/* NAND_DEVn_CFG0 bits */
>> +#define    DISABLE_STATUS_AFTER_WRITE    4
>> +#define    CW_PER_PAGE            6
>> +#define    UD_SIZE_BYTES            9
>> +#define    UD_SIZE_BYTES_MASK        GENMASK(18, 9)
>> +#define    ECC_PARITY_SIZE_BYTES_RS    19
>> +#define    SPARE_SIZE_BYTES        23
>> +#define    SPARE_SIZE_BYTES_MASK        GENMASK(26, 23)
>> +#define    NUM_ADDR_CYCLES            27
>> +#define    STATUS_BFR_READ            30
>> +#define    SET_RD_MODE_AFTER_STATUS    31
>> +
>> +/* NAND_DEVn_CFG0 bits */
>> +#define    DEV0_CFG1_ECC_DISABLE        0
>> +#define    WIDE_FLASH            1
>> +#define    NAND_RECOVERY_CYCLES        2
>> +#define    CS_ACTIVE_BSY            5
>> +#define    BAD_BLOCK_BYTE_NUM        6
>> +#define    BAD_BLOCK_IN_SPARE_AREA        16
>> +#define    WR_RD_BSY_GAP            17
>> +#define    ENABLE_BCH_ECC            27
>> +
>> +/* NAND_DEV0_ECC_CFG bits */
>> +#define    ECC_CFG_ECC_DISABLE        0
>> +#define    ECC_SW_RESET            1
>> +#define    ECC_MODE            4
>> +#define    ECC_PARITY_SIZE_BYTES_BCH    8
>> +#define    ECC_NUM_DATA_BYTES        16
>> +#define    ECC_NUM_DATA_BYTES_MASK        GENMASK(25, 16)
>> +#define    ECC_FORCE_CLK_OPEN        30
>> +
>> +/* NAND_DEV_CMD1 bits */
>> +#define    READ_ADDR            0
>> +
>> +/* NAND_DEV_CMD_VLD bits */
>> +#define    READ_START_VLD            BIT(0)
>> +#define    READ_STOP_VLD            BIT(1)
>> +#define    WRITE_START_VLD            BIT(2)
>> +#define    ERASE_START_VLD            BIT(3)
>> +#define    SEQ_READ_START_VLD        BIT(4)
>> +
>> +/* NAND_EBI2_ECC_BUF_CFG bits */
>> +#define    NUM_STEPS            0
>> +
>> +/* NAND_ERASED_CW_DETECT_CFG bits */
>> +#define    ERASED_CW_ECC_MASK        1
>> +#define    AUTO_DETECT_RES            0
>> +#define    MASK_ECC            BIT(ERASED_CW_ECC_MASK)
>> +#define    RESET_ERASED_DET        BIT(AUTO_DETECT_RES)
>> +#define    ACTIVE_ERASED_DET        (0 << AUTO_DETECT_RES)
>> +#define    CLR_ERASED_PAGE_DET        (RESET_ERASED_DET | MASK_ECC)
>> +#define    SET_ERASED_PAGE_DET        (ACTIVE_ERASED_DET | MASK_ECC)
>> +
>> +/* NAND_ERASED_CW_DETECT_STATUS bits */
>> +#define    PAGE_ALL_ERASED            BIT(7)
>> +#define    CODEWORD_ALL_ERASED        BIT(6)
>> +#define    PAGE_ERASED            BIT(5)
>> +#define    CODEWORD_ERASED            BIT(4)
>> +#define    ERASED_PAGE            (PAGE_ALL_ERASED | PAGE_ERASED)
>> +#define    ERASED_CW            (CODEWORD_ALL_ERASED | CODEWORD_ERASED)
>> +
>> +/* NAND_READ_LOCATION_n bits */
>> +#define READ_LOCATION_OFFSET        0
>> +#define READ_LOCATION_SIZE        16
>> +#define READ_LOCATION_LAST        31
>> +
>> +/* Version Mask */
>> +#define    NAND_VERSION_MAJOR_MASK        0xf0000000
>> +#define    NAND_VERSION_MAJOR_SHIFT    28
>> +#define    NAND_VERSION_MINOR_MASK        0x0fff0000
>> +#define    NAND_VERSION_MINOR_SHIFT    16
>> +
>> +/* NAND OP_CMDs */
>> +#define    OP_PAGE_READ            0x2
>> +#define    OP_PAGE_READ_WITH_ECC        0x3
>> +#define    OP_PAGE_READ_WITH_ECC_SPARE    0x4
>> +#define    OP_PAGE_READ_ONFI_READ        0x5
>> +#define    OP_PROGRAM_PAGE            0x6
>> +#define    OP_PAGE_PROGRAM_WITH_ECC    0x7
>> +#define    OP_PROGRAM_PAGE_SPARE        0x9
>> +#define    OP_BLOCK_ERASE            0xa
>> +#define    OP_CHECK_STATUS            0xc
>> +#define    OP_FETCH_ID            0xb
>> +#define    OP_RESET_DEVICE            0xd
>> +
>> +/* Default Value for NAND_DEV_CMD_VLD */
>> +#define NAND_DEV_CMD_VLD_VAL        (READ_START_VLD | WRITE_START_VLD | \
>> +                     ERASE_START_VLD | SEQ_READ_START_VLD)
>> +
>> +/* NAND_CTRL bits */
>> +#define    BAM_MODE_EN            BIT(0)
>> +
>> +/*
>> + * the NAND controller performs reads/writes with ECC in 516 byte chunks.
>> + * the driver calls the chunks 'step' or 'codeword' interchangeably
>> + */
>> +#define    NANDC_STEP_SIZE            512
>> +
>> +/*
>> + * the largest page size we support is 8K, this will have 16 steps/codewords
>> + * of 512 bytes each
>> + */
>> +#define    MAX_NUM_STEPS            (SZ_8K / NANDC_STEP_SIZE)
>> +
>> +/* we read at most 3 registers per codeword scan */
>> +#define    MAX_REG_RD            (3 * MAX_NUM_STEPS)
>> +
>> +#define QPIC_PER_CW_CMD_ELEMENTS    32
>> +#define QPIC_PER_CW_CMD_SGL        32
>> +#define QPIC_PER_CW_DATA_SGL        8
>> +
>> +#define QPIC_NAND_COMPLETION_TIMEOUT    msecs_to_jiffies(2000)
>> +
>> +/*
>> + * Flags used in DMA descriptor preparation helper functions
>> + * (i.e. read_reg_dma/write_reg_dma/read_data_dma/write_data_dma)
>> + */
>> +/* Don't set the EOT in current tx BAM sgl */
>> +#define NAND_BAM_NO_EOT            BIT(0)
>> +/* Set the NWD flag in current BAM sgl */
>> +#define NAND_BAM_NWD            BIT(1)
>> +/* Finish writing in the current BAM sgl and start writing in another BAM sgl */
>> +#define NAND_BAM_NEXT_SGL        BIT(2)
>> +
>> +/*
>> + * Returns the actual register address for all NAND_DEV_ registers
>> + * (i.e. NAND_DEV_CMD0, NAND_DEV_CMD1, NAND_DEV_CMD2 and NAND_DEV_CMD_VLD)
>> + */
>> +#define dev_cmd_reg_addr(nandc, reg) ((nandc)->props->dev_cmd_reg_start + (reg))
>> +
>> +/* Returns the NAND register physical address */
>> +#define nandc_reg_phys(chip, offset) ((chip)->base_phys + (offset))
>> +
>> +/* Returns the dma address for reg read buffer */
>> +#define reg_buf_dma_addr(chip, vaddr) \
>> +    ((chip)->reg_read_dma + \
>> +    ((u8 *)(vaddr) - (u8 *)(chip)->reg_read_buf))
>> +
>> +/*
>> + * Erased codeword status is being used two times in single transfer so this
>> + * flag will determine the current value of erased codeword status register
>> + */
>> +#define NAND_ERASED_CW_SET        BIT(4)
>> +
>> +#define MAX_ADDRESS_CYCLE        5
>> +
>> +/*
>> + * This data type corresponds to the BAM transaction which will be used for all
>> + * NAND transfers.
>> + * @bam_ce - the array of BAM command elements
>> + * @cmd_sgl - sgl for NAND BAM command pipe
>> + * @data_sgl - sgl for NAND BAM consumer/producer pipe
>> + * @last_data_desc - last DMA desc in data channel (tx/rx).
>> + * @last_cmd_desc - last DMA desc in command channel.
>> + * @txn_done - completion for NAND transfer.
>> + * @bam_ce_pos - the index in bam_ce which is available for next sgl
>> + * @bam_ce_start - the index in bam_ce which marks the start position ce
>> + *           for current sgl. It will be used for size calculation
>> + *           for current sgl
>> + * @cmd_sgl_pos - current index in command sgl.
>> + * @cmd_sgl_start - start index in command sgl.
>> + * @tx_sgl_pos - current index in data sgl for tx.
>> + * @tx_sgl_start - start index in data sgl for tx.
>> + * @rx_sgl_pos - current index in data sgl for rx.
>> + * @rx_sgl_start - start index in data sgl for rx.
>> + * @wait_second_completion - wait for second DMA desc completion before making
>> + *                 the NAND transfer completion.
>> + */
>> +struct bam_transaction {
>> +    struct bam_cmd_element *bam_ce;
>> +    struct scatterlist *cmd_sgl;
>> +    struct scatterlist *data_sgl;
>> +    struct dma_async_tx_descriptor *last_data_desc;
>> +    struct dma_async_tx_descriptor *last_cmd_desc;
>> +    struct completion txn_done;
>> +    u32 bam_ce_pos;
>> +    u32 bam_ce_start;
>> +    u32 cmd_sgl_pos;
>> +    u32 cmd_sgl_start;
>> +    u32 tx_sgl_pos;
>> +    u32 tx_sgl_start;
>> +    u32 rx_sgl_pos;
>> +    u32 rx_sgl_start;
>> +    bool wait_second_completion;
>> +};
>> +
>> +/*
>> + * This data type corresponds to the nand dma descriptor
>> + * @dma_desc - low level DMA engine descriptor
>> + * @list - list for desc_info
>> + *
>> + * @adm_sgl - sgl which will be used for single sgl dma descriptor. Only used by
>> + *          ADM
>> + * @bam_sgl - sgl which will be used for dma descriptor. Only used by BAM
>> + * @sgl_cnt - number of SGL in bam_sgl. Only used by BAM
>> + * @dir - DMA transfer direction
>> + */
>> +struct desc_info {
>> +    struct dma_async_tx_descriptor *dma_desc;
>> +    struct list_head node;
>> +
>> +    union {
>> +        struct scatterlist adm_sgl;
>> +        struct {
>> +            struct scatterlist *bam_sgl;
>> +            int sgl_cnt;
>> +        };
>> +    };
>> +    enum dma_data_direction dir;
>> +};
>> +
>> +/*
>> + * holds the current register values that we want to write. acts as a contiguous
>> + * chunk of memory which we use to write the controller registers through DMA.
>> + */
>> +struct nandc_regs {
>> +    __le32 cmd;
>> +    __le32 addr0;
>> +    __le32 addr1;
>> +    __le32 chip_sel;
>> +    __le32 exec;
>> +
>> +    __le32 cfg0;
>> +    __le32 cfg1;
>> +    __le32 ecc_bch_cfg;
>> +
>> +    __le32 clrflashstatus;
>> +    __le32 clrreadstatus;
>> +
>> +    __le32 cmd1;
>> +    __le32 vld;
>> +
>> +    __le32 orig_cmd1;
>> +    __le32 orig_vld;
>> +
>> +    __le32 ecc_buf_cfg;
>> +    __le32 read_location0;
>> +    __le32 read_location1;
>> +    __le32 read_location2;
>> +    __le32 read_location3;
>> +    __le32 read_location_last0;
>> +    __le32 read_location_last1;
>> +    __le32 read_location_last2;
>> +    __le32 read_location_last3;
>> +
>> +    __le32 erased_cw_detect_cfg_clr;
>> +    __le32 erased_cw_detect_cfg_set;
>> +};
>> +
>> +/*
>> + * NAND controller data struct
>> + *
>> + * @dev:            parent device
>> + *
>> + * @base:            MMIO base
>> + *
>> + * @core_clk:            controller clock
>> + * @aon_clk:            another controller clock
>> + *
>> + * @regs:            a contiguous chunk of memory for DMA register
>> + *                writes. contains the register values to be
>> + *                written to controller
>> + *
>> + * @props:            properties of current NAND controller,
>> + *                initialized via DT match data
>> + *
>> + * @controller:            base controller structure
>> + * @host_list:            list containing all the chips attached to the
>> + *                controller
>> + *
>> + * @chan:            dma channel
>> + * @cmd_crci:            ADM DMA CRCI for command flow control
>> + * @data_crci:            ADM DMA CRCI for data flow control
>> + *
>> + * @desc_list:            DMA descriptor list (list of desc_infos)
>> + *
>> + * @data_buffer:        our local DMA buffer for page read/writes,
>> + *                used when we can't use the buffer provided
>> + *                by upper layers directly
>> + * @reg_read_buf:        local buffer for reading back registers via DMA
>> + *
>> + * @base_phys:            physical base address of controller registers
>> + * @base_dma:            dma base address of controller registers
>> + * @reg_read_dma:        contains dma address for register read buffer
>> + *
>> + * @buf_size/count/start:    markers for chip->legacy.read_buf/write_buf
>> + *                functions
>> + * @max_cwperpage:        maximum QPIC codewords required. calculated
>> + *                from all connected NAND devices pagesize
>> + *
>> + * @reg_read_pos:        marker for data read in reg_read_buf
>> + *
>> + * @cmd1/vld:            some fixed controller register values
>> + *
>> + * @exec_opwrite:        flag to select correct number of code word
>> + *                while reading status
>> + */
>> +struct qcom_nand_controller {
>> +    struct device *dev;
>> +
>> +    void __iomem *base;
>> +
>> +    struct clk *core_clk;
>> +    struct clk *aon_clk;
>> +
>> +    struct nandc_regs *regs;
>> +    struct bam_transaction *bam_txn;
>> +
>> +    const struct qcom_nandc_props *props;
>> +
>> +    struct nand_controller controller;
>> +    struct list_head host_list;
>> +
>> +    union {
>> +        /* will be used only by QPIC for BAM DMA */
>> +        struct {
>> +            struct dma_chan *tx_chan;
>> +            struct dma_chan *rx_chan;
>> +            struct dma_chan *cmd_chan;
>> +        };
>> +
>> +        /* will be used only by EBI2 for ADM DMA */
>> +        struct {
>> +            struct dma_chan *chan;
>> +            unsigned int cmd_crci;
>> +            unsigned int data_crci;
>> +        };
>> +    };
>> +
>> +    struct list_head desc_list;
>> +
>> +    u8        *data_buffer;
>> +    __le32        *reg_read_buf;
>> +
>> +    phys_addr_t base_phys;
>> +    dma_addr_t base_dma;
>> +    dma_addr_t reg_read_dma;
>> +
>> +    int        buf_size;
>> +    int        buf_count;
>> +    int        buf_start;
>> +    unsigned int    max_cwperpage;
>> +
>> +    int reg_read_pos;
>> +
>> +    u32 cmd1, vld;
>> +    bool exec_opwrite;
>> +};
>> +
>> +/*
>> + * This data type corresponds to the NAND controller properties which varies
>> + * among different NAND controllers.
>> + * @ecc_modes - ecc mode for NAND
>> + * @dev_cmd_reg_start - NAND_DEV_CMD_* registers starting offset
>> + * @is_bam - whether NAND controller is using BAM
>> + * @is_qpic - whether NAND CTRL is part of qpic IP
>> + * @qpic_v2 - flag to indicate QPIC IP version 2
>> + * @use_codeword_fixup - whether NAND has different layout for boot partitions
>> + */
>> +struct qcom_nandc_props {
>> +    u32 ecc_modes;
>> +    u32 dev_cmd_reg_start;
>> +    bool is_bam;
>> +    bool is_qpic;
>> +    bool qpic_v2;
>> +    bool use_codeword_fixup;
>> +};
>> +
>> +void config_nand_page_read(struct nand_chip *chip);
>> +void free_bam_transaction(struct qcom_nand_controller *nandc);
>> +void qpic_bam_dma_done(void *data);
>> +void nandc_read_buffer_sync(struct qcom_nand_controller *nandc, bool is_cpu);
>> +__le32 *offset_to_nandc_reg(struct nandc_regs *regs, int offset);
>> +void clear_read_regs(struct qcom_nand_controller *nandc);
>> +int prep_adm_dma_desc(struct qcom_nand_controller *nandc, bool read,
>> +              int reg_off, const void *vaddr, int size,
>> +            bool flow_control);
>> +int submit_descs(struct qcom_nand_controller *nandc);
>> +int prepare_bam_async_desc(struct qcom_nand_controller *nandc,
>> +               struct dma_chan *chan, unsigned long flags);
>> +int prep_bam_dma_desc_cmd(struct qcom_nand_controller *nandc, bool read,
>> +              int reg_off, const void *vaddr,
>> +            int size, unsigned int flags);
>> +int prep_bam_dma_desc_data(struct qcom_nand_controller *nandc, bool read,
>> +               const void *vaddr,
>> +            int size, unsigned int flags);
>> +int read_reg_dma(struct qcom_nand_controller *nandc, int first,
>> +         int num_regs, unsigned int flags);
>> +int write_reg_dma(struct qcom_nand_controller *nandc, int first,
>> +          int num_regs, unsigned int flags);
>> +int read_data_dma(struct qcom_nand_controller *nandc, int reg_off,
>> +          const u8 *vaddr, int size, unsigned int flags);
>> +int write_data_dma(struct qcom_nand_controller *nandc, int reg_off,
>> +           const u8 *vaddr, int size, unsigned int flags);
>> +struct bam_transaction *alloc_bam_transaction(struct qcom_nand_controller *nandc);
>> +void clear_bam_transaction(struct qcom_nand_controller *nandc);
>> +void qcom_nandc_unalloc(struct qcom_nand_controller *nandc);
>> +int qcom_nandc_alloc(struct qcom_nand_controller *nandc);
>> +struct qcom_nand_controller *get_qcom_nand_controller(struct nand_chip *chip);
>> +
>> +#endif

On 2/15/2024 8:30 PM, Dmitry Baryshkov wrote:
> On Thu, 15 Feb 2024 at 15:53, Md Sadre Alam <quic_mdalam@quicinc.com> wrote:
>>
>> Add qpic_common.c file which hold all the common
>> qpic APIs which will be used by both qpic raw nand
>> driver and qpic spi nand driver.
>>
>> Co-developed-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
>> Signed-off-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
>> Co-developed-by: Varadarajan Narayanan <quic_varada@quicinc.com>
>> Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
>> Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
>> ---
>>   drivers/mtd/nand/Makefile            |    1 +
>>   drivers/mtd/nand/qpic_common.c       |  786 +++++++++++++++++
>>   drivers/mtd/nand/raw/qcom_nandc.c    | 1226 +-------------------------
>>   include/linux/mtd/nand-qpic-common.h |  488 ++++++++++
>>   4 files changed, 1291 insertions(+), 1210 deletions(-)
>>   create mode 100644 drivers/mtd/nand/qpic_common.c
>>   create mode 100644 include/linux/mtd/nand-qpic-common.h
>>
>> diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
>> index 19e1291ac4d5..131707a41293 100644
>> --- a/drivers/mtd/nand/Makefile
>> +++ b/drivers/mtd/nand/Makefile
>> @@ -12,3 +12,4 @@ nandcore-$(CONFIG_MTD_NAND_ECC) += ecc.o
>>   nandcore-$(CONFIG_MTD_NAND_ECC_SW_HAMMING) += ecc-sw-hamming.o
>>   nandcore-$(CONFIG_MTD_NAND_ECC_SW_BCH) += ecc-sw-bch.o
>>   nandcore-$(CONFIG_MTD_NAND_ECC_MXIC) += ecc-mxic.o
>> +obj-y += qpic_common.o
>> diff --git a/drivers/mtd/nand/qpic_common.c b/drivers/mtd/nand/qpic_common.c
>> new file mode 100644
>> index 000000000000..4d74ba888028
>> --- /dev/null
>> +++ b/drivers/mtd/nand/qpic_common.c
>> @@ -0,0 +1,786 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * QPIC Controller common API file.
>> + * Copyright (C) 2023  Qualcomm Inc.
>> + * Authors:    Md sadre Alam           <quic_mdalam@quicinc.com>
>> + *             Sricharan R             <quic_srichara@quicinc.com>
>> + *             Varadarajan Narayanan   <quic_varada@quicinc.com>
> 
> This is a bit of an exaggeration. You are moving code, not writing new
> code. Please retain the existing copyrights for the moved code.
Ok
> 
>> + *
>> + */
>> +
>> +#include <linux/mtd/nand-qpic-common.h>
>> +
>> +struct qcom_nand_controller *
>> +get_qcom_nand_controller(struct nand_chip *chip)
>> +{
>> +       return container_of(chip->controller, struct qcom_nand_controller,
>> +                           controller);
>> +}
>> +EXPORT_SYMBOL(get_qcom_nand_controller);
> 
> NAK for adding functions to the global export namespace without a
> proper driver-specific prefix.
Ok, will fix in next patch
> 
> Also, a bunch of the code here seems not so well thought. It was fine
> for an internal interface, but it doesn't look so good as a common
> wrapper. Please consider defining a sensible common code module
> interface instead.

  QPIC controller will support both raw NAND as well Serial nand interface.
  This common API file was the part of raw NAND driver , since for serial
  nand most of the APIs from raw nand driver will be re-used that's why i
  have created this common API file, so that QPIC serial nand driver
  drivers/spi/spi-qpic-snand.c and QPIC raw NAND driver
  drivers/mtd/nand/raw/qcom_nandc.c can used these common APIs.

  Could you please suggest how I should handle this in batter way.
> 
> At least each function that is being exported should get a kerneldoc.
Ok
> 
> Last, but not least, please use EXPORT_SYMBOL_GPL.
Ok
> 
>> +
>> +/*
>> + * Helper to prepare DMA descriptors for configuring registers
>> + * before reading a NAND page.
>> + */
>> +void config_nand_page_read(struct nand_chip *chip)
>> +{
>> +       struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
>> +
>> +       write_reg_dma(nandc, NAND_ADDR0, 2, 0);
>> +       write_reg_dma(nandc, NAND_DEV0_CFG0, 3, 0);
>> +       if (!nandc->props->qpic_v2)
>> +               write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1, 0);
>> +       write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1, 0);
>> +       write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1,
>> +                     NAND_ERASED_CW_SET | NAND_BAM_NEXT_SGL);
>> +}
>> +EXPORT_SYMBOL(config_nand_page_read);
>> +
>> +/* Frees the BAM transaction memory */
>> +void free_bam_transaction(struct qcom_nand_controller *nandc)
>> +{
>> +       struct bam_transaction *bam_txn = nandc->bam_txn;
>> +
>> +       devm_kfree(nandc->dev, bam_txn);
> 
> devm_kfree is usually a bad sign. Either the devm_kfree should be
> dropped (because the memory area is allocated only during probe / init
> and doesn't need to be freed manually) or use kalloc/kfree directly
> without devres wrapping.
Ok
> 
>> +}
>> +EXPORT_SYMBOL(free_bam_transaction);
>> +
> 
> [skipped the rest]
> 
>> --
>> 2.34.1
>>
>>
> 
> 
> --
> With best wishes
> Dmitry

Thanks for reviewing, Will fix all the comments in next patch.

Regards,
Alam.

On Tue, 20 Feb 2024 at 17:59, Md Sadre Alam <quic_mdalam@quicinc.com> wrote:
>
>
>
> On 2/15/2024 8:30 PM, Dmitry Baryshkov wrote:
> > On Thu, 15 Feb 2024 at 15:53, Md Sadre Alam <quic_mdalam@quicinc.com> wrote:
> >>
> >> Add qpic_common.c file which hold all the common
> >> qpic APIs which will be used by both qpic raw nand
> >> driver and qpic spi nand driver.
> >>
> >> Co-developed-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
> >> Signed-off-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
> >> Co-developed-by: Varadarajan Narayanan <quic_varada@quicinc.com>
> >> Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
> >> Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
> >> ---
> >>   drivers/mtd/nand/Makefile            |    1 +
> >>   drivers/mtd/nand/qpic_common.c       |  786 +++++++++++++++++
> >>   drivers/mtd/nand/raw/qcom_nandc.c    | 1226 +-------------------------
> >>   include/linux/mtd/nand-qpic-common.h |  488 ++++++++++
> >>   4 files changed, 1291 insertions(+), 1210 deletions(-)
> >>   create mode 100644 drivers/mtd/nand/qpic_common.c
> >>   create mode 100644 include/linux/mtd/nand-qpic-common.h
> >>
> >> diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
> >> index 19e1291ac4d5..131707a41293 100644
> >> --- a/drivers/mtd/nand/Makefile
> >> +++ b/drivers/mtd/nand/Makefile
> >> @@ -12,3 +12,4 @@ nandcore-$(CONFIG_MTD_NAND_ECC) += ecc.o
> >>   nandcore-$(CONFIG_MTD_NAND_ECC_SW_HAMMING) += ecc-sw-hamming.o
> >>   nandcore-$(CONFIG_MTD_NAND_ECC_SW_BCH) += ecc-sw-bch.o
> >>   nandcore-$(CONFIG_MTD_NAND_ECC_MXIC) += ecc-mxic.o
> >> +obj-y += qpic_common.o
> >> diff --git a/drivers/mtd/nand/qpic_common.c b/drivers/mtd/nand/qpic_common.c
> >> new file mode 100644
> >> index 000000000000..4d74ba888028
> >> --- /dev/null
> >> +++ b/drivers/mtd/nand/qpic_common.c
> >> @@ -0,0 +1,786 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +/*
> >> + * QPIC Controller common API file.
> >> + * Copyright (C) 2023  Qualcomm Inc.
> >> + * Authors:    Md sadre Alam           <quic_mdalam@quicinc.com>
> >> + *             Sricharan R             <quic_srichara@quicinc.com>
> >> + *             Varadarajan Narayanan   <quic_varada@quicinc.com>
> >
> > This is a bit of an exaggeration. You are moving code, not writing new
> > code. Please retain the existing copyrights for the moved code.
> Ok
> >
> >> + *
> >> + */
> >> +
> >> +#include <linux/mtd/nand-qpic-common.h>
> >> +
> >> +struct qcom_nand_controller *
> >> +get_qcom_nand_controller(struct nand_chip *chip)
> >> +{
> >> +       return container_of(chip->controller, struct qcom_nand_controller,
> >> +                           controller);
> >> +}
> >> +EXPORT_SYMBOL(get_qcom_nand_controller);
> >
> > NAK for adding functions to the global export namespace without a
> > proper driver-specific prefix.
> Ok, will fix in next patch
> >
> > Also, a bunch of the code here seems not so well thought. It was fine
> > for an internal interface, but it doesn't look so good as a common
> > wrapper. Please consider defining a sensible common code module
> > interface instead.
>
>   QPIC controller will support both raw NAND as well Serial nand interface.
>   This common API file was the part of raw NAND driver , since for serial
>   nand most of the APIs from raw nand driver will be re-used that's why i
>   have created this common API file, so that QPIC serial nand driver
>   drivers/spi/spi-qpic-snand.c and QPIC raw NAND driver
>   drivers/mtd/nand/raw/qcom_nandc.c can used these common APIs.
>
>   Could you please suggest how I should handle this in batter way.

Yes. Start by designing common accessor functions that form a
sufficient and complete API to access the hardware functionality. A
set of functions blindly moved from the existing driver usually do not
make such an API, because usually nobody cares enough about the driver
internals. It should be something that external user (NAND, SPI, etc)
can use without looking into the actual implementation of these
functions.

On 2/20/2024 9:37 PM, Dmitry Baryshkov wrote:
> On Tue, 20 Feb 2024 at 17:59, Md Sadre Alam <quic_mdalam@quicinc.com> wrote:
>>
>>
>>
>> On 2/15/2024 8:30 PM, Dmitry Baryshkov wrote:
>>> On Thu, 15 Feb 2024 at 15:53, Md Sadre Alam <quic_mdalam@quicinc.com> wrote:
>>>>
>>>> Add qpic_common.c file which hold all the common
>>>> qpic APIs which will be used by both qpic raw nand
>>>> driver and qpic spi nand driver.
>>>>
>>>> Co-developed-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
>>>> Signed-off-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
>>>> Co-developed-by: Varadarajan Narayanan <quic_varada@quicinc.com>
>>>> Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
>>>> Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
>>>> ---
>>>>    drivers/mtd/nand/Makefile            |    1 +
>>>>    drivers/mtd/nand/qpic_common.c       |  786 +++++++++++++++++
>>>>    drivers/mtd/nand/raw/qcom_nandc.c    | 1226 +-------------------------
>>>>    include/linux/mtd/nand-qpic-common.h |  488 ++++++++++
>>>>    4 files changed, 1291 insertions(+), 1210 deletions(-)
>>>>    create mode 100644 drivers/mtd/nand/qpic_common.c
>>>>    create mode 100644 include/linux/mtd/nand-qpic-common.h
>>>>
>>>> diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
>>>> index 19e1291ac4d5..131707a41293 100644
>>>> --- a/drivers/mtd/nand/Makefile
>>>> +++ b/drivers/mtd/nand/Makefile
>>>> @@ -12,3 +12,4 @@ nandcore-$(CONFIG_MTD_NAND_ECC) += ecc.o
>>>>    nandcore-$(CONFIG_MTD_NAND_ECC_SW_HAMMING) += ecc-sw-hamming.o
>>>>    nandcore-$(CONFIG_MTD_NAND_ECC_SW_BCH) += ecc-sw-bch.o
>>>>    nandcore-$(CONFIG_MTD_NAND_ECC_MXIC) += ecc-mxic.o
>>>> +obj-y += qpic_common.o
>>>> diff --git a/drivers/mtd/nand/qpic_common.c b/drivers/mtd/nand/qpic_common.c
>>>> new file mode 100644
>>>> index 000000000000..4d74ba888028
>>>> --- /dev/null
>>>> +++ b/drivers/mtd/nand/qpic_common.c
>>>> @@ -0,0 +1,786 @@
>>>> +// SPDX-License-Identifier: GPL-2.0
>>>> +/*
>>>> + * QPIC Controller common API file.
>>>> + * Copyright (C) 2023  Qualcomm Inc.
>>>> + * Authors:    Md sadre Alam           <quic_mdalam@quicinc.com>
>>>> + *             Sricharan R             <quic_srichara@quicinc.com>
>>>> + *             Varadarajan Narayanan   <quic_varada@quicinc.com>
>>>
>>> This is a bit of an exaggeration. You are moving code, not writing new
>>> code. Please retain the existing copyrights for the moved code.
>> Ok
>>>
>>>> + *
>>>> + */
>>>> +
>>>> +#include <linux/mtd/nand-qpic-common.h>
>>>> +
>>>> +struct qcom_nand_controller *
>>>> +get_qcom_nand_controller(struct nand_chip *chip)
>>>> +{
>>>> +       return container_of(chip->controller, struct qcom_nand_controller,
>>>> +                           controller);
>>>> +}
>>>> +EXPORT_SYMBOL(get_qcom_nand_controller);
>>>
>>> NAK for adding functions to the global export namespace without a
>>> proper driver-specific prefix.
>> Ok, will fix in next patch
>>>
>>> Also, a bunch of the code here seems not so well thought. It was fine
>>> for an internal interface, but it doesn't look so good as a common
>>> wrapper. Please consider defining a sensible common code module
>>> interface instead.
>>
>>    QPIC controller will support both raw NAND as well Serial nand interface.
>>    This common API file was the part of raw NAND driver , since for serial
>>    nand most of the APIs from raw nand driver will be re-used that's why i
>>    have created this common API file, so that QPIC serial nand driver
>>    drivers/spi/spi-qpic-snand.c and QPIC raw NAND driver
>>    drivers/mtd/nand/raw/qcom_nandc.c can used these common APIs.
>>
>>    Could you please suggest how I should handle this in batter way.
> 
> Yes. Start by designing common accessor functions that form a
> sufficient and complete API to access the hardware functionality. A
> set of functions blindly moved from the existing driver usually do not
> make such an API, because usually nobody cares enough about the driver
> internals. It should be something that external user (NAND, SPI, etc)
> can use without looking into the actual implementation of these
> functions.
  Thanks for suggestion. Will make the Common API more generic and
  post in next patch.
>