[v1,2/2] spi: add support for sophgo spi-nor controller

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index bc7021da2fe9..41ad7c0aaab8 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -971,6 +971,15 @@  config SPI_SN_F_OSPI
 	  for connecting an SPI Flash memory over up to 8-bit wide bus.
 	  It supports indirect access mode only.
 
+config SPI_SOPHGO_CV1800
+	tristate "Sophgo SPI NOR Controller"
+	depends on ARCH_SOPHGO || COMPILE_TEST
+	help
+	  This enables support for the Sophgo SPI NOR controller,
+	  which supports Dual/Qual read and write operations while
+	  also supporting 3Byte address devices and 4Byte address
+	  devices.
+
 config SPI_SPRD
 	tristate "Spreadtrum SPI controller"
 	depends on ARCH_SPRD || COMPILE_TEST
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 4ff8d725ba5e..a25549155106 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -128,6 +128,7 @@  obj-$(CONFIG_SPI_SH_SCI)		+= spi-sh-sci.o
 obj-$(CONFIG_SPI_SIFIVE)		+= spi-sifive.o
 obj-$(CONFIG_SPI_SLAVE_MT27XX)          += spi-slave-mt27xx.o
 obj-$(CONFIG_SPI_SN_F_OSPI)		+= spi-sn-f-ospi.o
+obj-$(CONFIG_SPI_SOPHGO_CV1800)		+= spi-sophgo-cv1800.o
 obj-$(CONFIG_SPI_SPRD)			+= spi-sprd.o
 obj-$(CONFIG_SPI_SPRD_ADI)		+= spi-sprd-adi.o
 obj-$(CONFIG_SPI_STM32) 		+= spi-stm32.o
diff --git a/drivers/spi/spi-sophgo-cv1800.c b/drivers/spi/spi-sophgo-cv1800.c
new file mode 100644
index 000000000000..2e453b7d45f0
--- /dev/null
+++ b/drivers/spi/spi-sophgo-cv1800.c
@@ -0,0 +1,370 @@ 
+// SPDX-License-Identifier: GPL-2.0
+//
+// Sophgo SPI NOR controller driver
+//
+// Copyright (C) 2020 Jingbao Qiu <qiujingbao.dlmu@gmail.com>
+
+#include <linux/bitfield.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi-mem.h>
+
+#define SOPHGO_SPI_CTRL                 0x000
+#define SOPHGO_SPI_CE_CTRL              0x004
+#define SOPHGO_SPI_DLY_CTRL             0x008
+#define SOPHGO_SPI_DMMR                 0x00C
+#define SOPHGO_SPI_TRAN_CSR             0x010
+#define SOPHGO_SPI_TRAN_NUM             0x014
+#define SOPHGO_SPI_FIFO_PORT            0x018
+#define SOPHGO_SPI_FIFO_PT              0x020
+#define SOPHGO_SPI_INT_STS              0x028
+
+#define SOPHGO_NOR_CTRL_SCK_DIV_MASK    GENMASK(10, 0)
+#define SOPHGO_NOR_CTRL_DEFAULT_DIV     4
+#define SOPHGO_NOR_DLY_CTRL_NEG_SAMPLE  BIT(14)
+
+#define SOPHGO_NOR_CE_MANUAL            BIT(0)
+#define SOPHGO_NOR_CE_MANUAL_EN         BIT(1)
+#define SOPHGO_NOR_CE_ENABLE            (SOPHGO_NOR_CE_MANUAL | SOPHGO_NOR_CE_MANUAL_EN)
+#define SOPHGO_NOR_CE_DISABLE           SOPHGO_NOR_CE_MANUAL_EN
+#define SOPHGO_NOR_CE_HARDWARE          0
+
+#define SOPHGO_NOR_TRAN_MODE_RX         BIT(0)
+#define SOPHGO_NOR_TRAN_MODE_TX         BIT(1)
+#define SOPHGO_NOR_TRAN_MODE_MASK       GENMASK(1, 0)
+#define SOPHGO_NOR_TRANS_FAST           BIT(3)
+#define SOPHGO_NOR_TRANS_BUS_WIDTH(n)   (n << 4)
+#define SOPHGO_NOR_TRANS_BUS_WIDTH_MASK GENMASK(5, 4)
+
+#define SOPHGO_NOR_TRANS_MIOS           BIT(7)
+
+#define SOPHGO_NOR_TRAN_ADDR(n)         (n << 8)
+#define SOPHGO_NOR_TRANS_ADDR_MASK      GENMASK(10, 8)
+#define SOPHGO_NOR_TRANS_CMD            BIT(11)
+#define SOPHGO_NOR_TRAN_FIFO_MASK       GENMASK(13, 12)
+#define SOPHGO_NOR_TRAN_FIFO_8_BYTE     GENMASK(13, 12)
+#define SOPHGO_NOR_TRAN_GO_BUSY         BIT(15)
+
+#define SOPHGO_NOR_TRANS_DMMR_EN        BIT(20)
+#define SOPHGO_NOR_TRANS_DMMR_CMD       BIT(21)
+
+#define SOPHGO_NOR_TRANS_MMIO									\
+	(SOPHGO_NOR_TRANS_FAST | SOPHGO_NOR_TRANS_DMMR_EN |			\
+		SOPHGO_NOR_TRANS_DMMR_CMD | SOPHGO_NOR_TRANS_MIOS |		\
+		SOPHGO_NOR_TRAN_MODE_RX | SOPHGO_NOR_TRAN_FIFO_8_BYTE)
+
+#define SOPHGO_NOR_TRANS_PORT								\
+	(SOPHGO_NOR_TRAN_MODE_MASK | SOPHGO_NOR_TRANS_ADDR_MASK |	\
+		SOPHGO_NOR_TRAN_FIFO_MASK | SOPHGO_NOR_TRANS_BUS_WIDTH_MASK |	\
+		SOPHGO_NOR_TRANS_BUS_WIDTH_MASK)
+
+#define SOPHGO_NOR_FIFO_CAPACITY  8
+#define SOPHGO_NOR_FIFO_AVAI_MASK GENMASK(3, 0)
+
+#define SOPHGO_NOR_INT_TRAN_DONE  BIT(0)
+#define SOPHGO_NOR_INT_RD_FIFO    BIT(1)
+#define SOPHGO_NOR_INT_WR_FIFO    BIT(2)
+
+struct sophgo_nor {
+	struct spi_controller *ctlr;
+	struct device *dev;
+	void __iomem *io_base;
+	uint32_t tran_csr_orig;
+	uint32_t sck_div_orig;
+	struct mutex lock;
+};
+
+static uint32_t sophgo_nor_clk_setup(struct sophgo_nor *spif, uint32_t sck_div)
+{
+	uint32_t reg;
+	uint32_t old_clk;
+
+	reg = readl(spif->io_base + SOPHGO_SPI_DLY_CTRL);
+
+	if (sck_div < SOPHGO_NOR_CTRL_DEFAULT_DIV)
+		reg |= SOPHGO_NOR_DLY_CTRL_NEG_SAMPLE;
+
+	writel(reg, spif->io_base + SOPHGO_SPI_DLY_CTRL);
+
+	reg = readl(spif->io_base + SOPHGO_SPI_CTRL);
+	old_clk = FIELD_GET(SOPHGO_NOR_CTRL_SCK_DIV_MASK, reg);
+
+	reg &= ~SOPHGO_NOR_CTRL_SCK_DIV_MASK;
+	reg |= sck_div;
+	writel(reg, spif->io_base + SOPHGO_SPI_CTRL);
+
+	return old_clk;
+}
+
+static inline uint32_t sophgo_nor_trans_csr_config(struct sophgo_nor *spif,
+					       const struct spi_mem_op *op)
+{
+	uint32_t tran_csr = 0;
+
+	if (op->dummy.nbytes)
+		tran_csr |= (op->dummy.nbytes * 8) / op->dummy.buswidth << 16;
+
+	tran_csr |= SOPHGO_NOR_TRANS_MMIO;
+	tran_csr |= SOPHGO_NOR_TRANS_BUS_WIDTH(op->data.buswidth / 2);
+	tran_csr |= SOPHGO_NOR_TRAN_ADDR(op->addr.nbytes);
+
+	return tran_csr;
+}
+
+static void sophgo_nor_config_mmio(struct sophgo_nor *spif,
+				   const struct spi_mem_op *op,
+				   uint32_t enabled)
+{
+	uint32_t ctrl, tran_csr;
+
+	if (enabled) {
+		spif->tran_csr_orig =
+			readl(spif->io_base + SOPHGO_SPI_TRAN_CSR);
+		tran_csr = sophgo_nor_trans_csr_config(spif, op);
+		ctrl = SOPHGO_NOR_CE_HARDWARE;
+	} else {
+		tran_csr = spif->tran_csr_orig;
+		ctrl = SOPHGO_NOR_CE_ENABLE;
+	}
+
+	writel(tran_csr, spif->io_base + SOPHGO_SPI_TRAN_CSR);
+	writel(ctrl, spif->io_base + SOPHGO_SPI_CE_CTRL);
+	writel(enabled, spif->io_base + SOPHGO_SPI_DMMR);
+}
+
+static void sophgo_nor_config_port(struct sophgo_nor *spif, uint32_t enabled)
+{
+	uint32_t ctrl = SOPHGO_NOR_CE_ENABLE;
+
+	if (enabled) {
+		ctrl = SOPHGO_NOR_CE_MANUAL_EN;
+		writel(!enabled, spif->io_base + SOPHGO_SPI_DMMR);
+	}
+
+	writel(ctrl, spif->io_base + SOPHGO_SPI_CE_CTRL);
+}
+
+static int sophgo_nor_xfer(struct sophgo_nor *spif, const uint8_t *dout,
+			   uint8_t *din, uint32_t data_bytes,
+			   uint32_t bus_width)
+{
+	uint32_t xfer_size, off;
+	uint32_t fifo_cnt;
+	uint32_t interrupt_mask = 0;
+	uint32_t stat, tran_csr = 0;
+	int ret = 0;
+
+	writel(0, spif->io_base + SOPHGO_SPI_INT_STS);
+	writel(0, spif->io_base + SOPHGO_SPI_FIFO_PT);
+
+	writew(data_bytes, spif->io_base + SOPHGO_SPI_TRAN_NUM);
+
+	if (din && dout)
+		return -1;
+	else if (!din && !dout)
+		return -1;
+
+	tran_csr = readw(spif->io_base + SOPHGO_SPI_TRAN_CSR);
+
+	tran_csr &= ~SOPHGO_NOR_TRANS_PORT;
+
+	tran_csr |= SOPHGO_NOR_TRAN_FIFO_8_BYTE;
+	tran_csr |= SOPHGO_NOR_TRAN_GO_BUSY;
+	tran_csr |= (bus_width / 2) << 4;
+
+	interrupt_mask |= SOPHGO_NOR_INT_TRAN_DONE;
+
+	if (din) {
+		tran_csr |= SOPHGO_NOR_TRAN_MODE_RX;
+		interrupt_mask |= SOPHGO_NOR_INT_RD_FIFO;
+		spif->sck_div_orig =
+			sophgo_nor_clk_setup(spif, SOPHGO_NOR_CTRL_DEFAULT_DIV);
+	} else if (dout) {
+		tran_csr |= SOPHGO_NOR_TRAN_MODE_TX;
+		interrupt_mask |= SOPHGO_NOR_INT_WR_FIFO;
+	}
+
+	writew(tran_csr, spif->io_base + SOPHGO_SPI_TRAN_CSR);
+
+	ret = readb_poll_timeout(spif->io_base + SOPHGO_SPI_INT_STS, stat,
+				 stat & interrupt_mask, 10, 30);
+	if (ret)
+		dev_warn(spif->dev, "%s stat timedout\n", __func__);
+
+	off = 0;
+	while (off < data_bytes) {
+		xfer_size = min_t(uint32_t, data_bytes - off,
+				  SOPHGO_NOR_FIFO_CAPACITY);
+
+		fifo_cnt = readl(spif->io_base + SOPHGO_SPI_FIFO_PT) &
+			   SOPHGO_NOR_FIFO_AVAI_MASK;
+
+		if (fifo_cnt > SOPHGO_NOR_FIFO_CAPACITY)
+			goto exit;
+
+		if (din)
+			xfer_size = min(xfer_size, fifo_cnt);
+		else
+			xfer_size = min_t(uint32_t, xfer_size,
+					  SOPHGO_NOR_FIFO_CAPACITY - fifo_cnt);
+
+		while (xfer_size--) {
+			if (din)
+				*(din + off) = readb(spif->io_base +
+						     SOPHGO_SPI_FIFO_PORT);
+			else
+				writeb(*(dout + off),
+				       spif->io_base + SOPHGO_SPI_FIFO_PORT);
+			off++;
+		}
+	}
+
+	ret = readb_poll_timeout(spif->io_base + SOPHGO_SPI_INT_STS, stat,
+				 (stat & interrupt_mask), 10, 30);
+	if (ret) {
+		dev_warn(spif->dev, " %s command timed out %x\n", __func__,
+			 stat);
+	}
+
+exit:
+	writeb(0, spif->io_base + SOPHGO_SPI_FIFO_PT);
+	stat = readb(spif->io_base + SOPHGO_SPI_INT_STS) & ~interrupt_mask;
+	writeb(stat, spif->io_base + SOPHGO_SPI_INT_STS);
+
+	if (din)
+		sophgo_nor_clk_setup(spif, spif->sck_div_orig);
+
+	return 0;
+}
+
+static int sophgo_nor_port_trans(struct sophgo_nor *spif,
+				 const struct spi_mem_op *op)
+{
+	const uint8_t *dout = NULL;
+	uint8_t *din = NULL;
+	uint32_t addr;
+
+	sophgo_nor_config_port(spif, 1);
+
+	if (op->cmd.nbytes)
+		sophgo_nor_xfer(spif, (uint8_t *)&op->cmd.opcode, NULL,
+				op->cmd.nbytes, op->cmd.buswidth);
+
+	if (op->addr.nbytes) {
+		addr = cpu_to_be32(op->addr.val);
+		sophgo_nor_xfer(spif, (uint8_t *)&addr, NULL, op->addr.nbytes,
+				op->addr.buswidth);
+	}
+
+	if (op->data.dir == SPI_MEM_DATA_IN)
+		din = op->data.buf.in;
+	else if (op->data.dir == SPI_MEM_DATA_OUT)
+		dout = op->data.buf.out;
+
+	sophgo_nor_xfer(spif, dout, din, op->data.nbytes, op->data.buswidth);
+
+	sophgo_nor_config_port(spif, 0);
+
+	return 0;
+}
+
+static void sophgo_nore_read_mmio(struct sophgo_nor *spif,
+				  const struct spi_mem_op *op)
+{
+	sophgo_nor_config_mmio(spif, op, 1);
+	memcpy_fromio(op->data.buf.in, spif->io_base + op->addr.val,
+		      op->data.nbytes);
+	sophgo_nor_config_mmio(spif, op, 0);
+}
+
+static int sophgo_nor_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
+{
+	struct sophgo_nor *spif;
+
+	spif = spi_controller_get_devdata(mem->spi->controller);
+
+	mutex_lock(&spif->lock);
+	if (op->data.dir == SPI_MEM_DATA_IN && op->data.nbytes &&
+	    op->addr.nbytes == 4) {
+		sophgo_nore_read_mmio(spif, op);
+		goto exit;
+	}
+
+	sophgo_nor_port_trans(spif, op);
+
+exit:
+	mutex_unlock(&spif->lock);
+	return 0;
+}
+
+static const struct spi_controller_mem_ops sophgo_nor_mem_ops = {
+	.exec_op = sophgo_nor_exec_op,
+};
+
+static const struct of_device_id sophgo_nor_match[] = {
+	{ .compatible = "sophgo,cv1800b-nor" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sophgo_nor_match);
+
+static int sophgo_nor_probe(struct platform_device *pdev)
+{
+	struct spi_controller *ctlr;
+	struct sophgo_nor *sp;
+	void __iomem *base;
+
+	ctlr = devm_spi_alloc_host(&pdev->dev, sizeof(*sp));
+	if (!ctlr)
+		return -ENOMEM;
+
+	sp = spi_controller_get_devdata(ctlr);
+	dev_set_drvdata(&pdev->dev, ctlr);
+
+	sp->dev = &pdev->dev;
+	sp->ctlr = ctlr;
+
+	sp->io_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	ctlr->num_chipselect = 1;
+	ctlr->dev.of_node = pdev->dev.of_node;
+	ctlr->bits_per_word_mask = SPI_BPW_MASK(8);
+	ctlr->auto_runtime_pm = false;
+	ctlr->mem_ops = &sophgo_nor_mem_ops;
+	ctlr->mode_bits = SPI_RX_DUAL | SPI_TX_DUAL | SPI_RX_QUAD | SPI_TX_QUAD;
+
+	mutex_init(&sp->lock);
+
+	sophgo_nor_config_port(sp, 1);
+
+	return devm_spi_register_controller(&pdev->dev, ctlr);
+}
+
+static int sophgo_nor_remove(struct platform_device *pdev)
+{
+	struct sophgo_nor *spif = platform_get_drvdata(pdev);
+
+	mutex_destroy(&spif->lock);
+	return 0;
+}
+
+static struct platform_driver sophgo_nor_driver = {
+	.driver = {
+		.name = "sophgo-spif",
+		.of_match_table = sophgo_nor_match,
+	},
+	.probe = sophgo_nor_probe,
+	.remove = sophgo_nor_remove,
+};
+
+module_platform_driver(sophgo_nor_driver);
+
+MODULE_DESCRIPTION("Sophgo SPI NOR controller driver");
+MODULE_AUTHOR("Jingbao Qiu <qiujingbao.dlmu@gmail.com>");
+MODULE_LICENSE("GPL");