[PATCHv2,3/4] usb: musb: ux500: add dma glue layer for ux500

diff --git a/drivers/usb/musb/ux500_dma.c b/drivers/usb/musb/ux500_dma.c
new file mode 100644
index 0000000..cecace4
--- /dev/null
+++ b/drivers/usb/musb/ux500_dma.c
@@ -0,0 +1,422 @@ 
+/*
+ * drivers/usb/musb/ux500_dma.c
+ *
+ * U8500 and U5500 DMA support code
+ *
+ * Copyright (C) 2009 STMicroelectronics
+ * Copyright (C) 2011 ST-Ericsson SA
+ * Authors:
+ *	Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
+ *	Praveena Nadahally <praveen.nadahally@stericsson.com>
+ *	Rajaram Regupathy <ragupathy.rajaram@stericsson.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/pfn.h>
+#include <mach/usb.h>
+#include "musb_core.h"
+
+struct ux500_dma_channel {
+	struct dma_channel channel;
+	struct ux500_dma_controller *controller;
+	struct musb_hw_ep *hw_ep;
+	struct work_struct channel_work;
+	struct dma_chan *dma_chan;
+	unsigned int cur_len;
+	dma_cookie_t cookie;
+	u8 ch_num;
+	u8 is_tx;
+	u8 is_allocated;
+};
+
+struct ux500_dma_controller {
+	struct dma_controller controller;
+	struct ux500_dma_channel rx_channel[UX500_MUSB_DMA_NUM_RX_CHANNELS];
+	struct ux500_dma_channel tx_channel[UX500_MUSB_DMA_NUM_TX_CHANNELS];
+	u32	num_rx_channels;
+	u32	num_tx_channels;
+	void *private_data;
+	dma_addr_t phy_base;
+};
+
+/* Work function invoked from DMA callback to handle tx transfers. */
+static void ux500_tx_work(struct work_struct *data)
+{
+	struct ux500_dma_channel *ux500_channel = container_of(data,
+		struct ux500_dma_channel, channel_work);
+	struct musb_hw_ep       *hw_ep = ux500_channel->hw_ep;
+	struct musb *musb = hw_ep->musb;
+	unsigned long flags;
+
+	DBG(4, "DMA tx transfer done on hw_ep=%d\n", hw_ep->epnum);
+
+	spin_lock_irqsave(&musb->lock, flags);
+	ux500_channel->channel.actual_len = ux500_channel->cur_len;
+	ux500_channel->channel.status = MUSB_DMA_STATUS_FREE;
+	musb_dma_completion(musb, hw_ep->epnum,
+				ux500_channel->is_tx);
+	spin_unlock_irqrestore(&musb->lock, flags);
+}
+
+/* Work function invoked from DMA callback to handle rx transfers. */
+static void ux500_rx_work(struct work_struct *data)
+{
+	struct ux500_dma_channel *ux500_channel = container_of(data,
+		struct ux500_dma_channel, channel_work);
+	struct musb_hw_ep       *hw_ep = ux500_channel->hw_ep;
+	struct musb *musb = hw_ep->musb;
+	unsigned long flags;
+
+	DBG(4, "DMA rx transfer done on hw_ep=%d\n", hw_ep->epnum);
+
+	spin_lock_irqsave(&musb->lock, flags);
+	ux500_channel->channel.actual_len = ux500_channel->cur_len;
+	ux500_channel->channel.status = MUSB_DMA_STATUS_FREE;
+	musb_dma_completion(musb, hw_ep->epnum,
+		ux500_channel->is_tx);
+	spin_unlock_irqrestore(&musb->lock, flags);
+}
+
+void ux500_dma_callback(void *private_data)
+{
+	struct dma_channel *channel = (struct dma_channel *)private_data;
+	struct ux500_dma_channel *ux500_channel = channel->private_data;
+
+	schedule_work(&ux500_channel->channel_work);
+}
+
+static bool ux500_configure_channel(struct dma_channel *channel,
+				u16 packet_sz, u8 mode,
+				dma_addr_t dma_addr, u32 len)
+{
+	struct ux500_dma_channel *ux500_channel = channel->private_data;
+	struct musb_hw_ep *hw_ep = ux500_channel->hw_ep;
+	struct dma_chan *dma_chan = ux500_channel->dma_chan;
+	struct dma_async_tx_descriptor *dma_desc;
+	enum dma_data_direction direction;
+	struct scatterlist sg;
+	struct dma_slave_config slave_conf;
+	enum dma_slave_buswidth addr_width;
+	dma_addr_t usb_fifo_addr = (MUSB_FIFO_OFFSET(hw_ep->epnum) +
+					ux500_channel->controller->phy_base);
+
+	DBG(4, "packet_sz=%d, mode=%d, dma_addr=0x%x, len=%d is_tx=%d\n",
+			packet_sz, mode, dma_addr, len, ux500_channel->is_tx);
+
+	ux500_channel->cur_len = len;
+
+	sg_init_table(&sg, 1);
+	sg_set_page(&sg, pfn_to_page(PFN_DOWN(dma_addr)), len,
+					    offset_in_page(dma_addr));
+	sg_dma_address(&sg) = dma_addr;
+	sg_dma_len(&sg) = len;
+
+	direction = ux500_channel->is_tx ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
+	addr_width = (len & 0x3) ? DMA_SLAVE_BUSWIDTH_1_BYTE :
+					DMA_SLAVE_BUSWIDTH_4_BYTES;
+
+	slave_conf.direction = direction;
+	if (direction == DMA_FROM_DEVICE) {
+		slave_conf.src_addr = usb_fifo_addr;
+		slave_conf.src_addr_width = addr_width;
+		slave_conf.src_maxburst = 16;
+	} else {
+		slave_conf.dst_addr = usb_fifo_addr;
+		slave_conf.dst_addr_width = addr_width;
+		slave_conf.dst_maxburst = 16;
+	}
+	dma_chan->device->device_control(dma_chan, DMA_SLAVE_CONFIG,
+					     (unsigned long) &slave_conf);
+
+	dma_desc = dma_chan->device->
+			device_prep_slave_sg(dma_chan, &sg, 1, direction,
+					     DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!dma_desc)
+		return false;
+
+	dma_desc->callback = ux500_dma_callback;
+	dma_desc->callback_param = channel;
+	ux500_channel->cookie = dma_desc->tx_submit(dma_desc);
+
+	dma_async_issue_pending(dma_chan);
+
+	return true;
+}
+
+static struct dma_channel *ux500_dma_channel_allocate(struct dma_controller *c,
+				struct musb_hw_ep *hw_ep, u8 is_tx)
+{
+	struct ux500_dma_controller *controller = container_of(c,
+			struct ux500_dma_controller, controller);
+	struct ux500_dma_channel *ux500_channel = NULL;
+	u8 ch_num = hw_ep->epnum - 1;
+	u32 max_ch;
+
+	/* Max 8 DMA channels (0 - 7). Each DMA channel can only be allocated
+	 * to specified hw_ep. For example DMA channel 0 can only be allocated
+	 * to hw_ep 1 and 9.
+	 */
+	if (ch_num > 7)
+		ch_num -= 8;
+
+	max_ch = is_tx ? controller->num_tx_channels :
+			controller->num_rx_channels;
+
+	if (ch_num >= max_ch)
+		return NULL;
+
+	ux500_channel = is_tx ? &(controller->tx_channel[ch_num]) :
+				&(controller->rx_channel[ch_num]) ;
+
+	/* Check if channel is already used. */
+	if (ux500_channel->is_allocated)
+		return NULL;
+
+	ux500_channel->hw_ep = hw_ep;
+	ux500_channel->is_allocated = 1;
+
+	DBG(7, "hw_ep=%d, is_tx=0x%x, channel=%d\n",
+		hw_ep->epnum, is_tx, ch_num);
+
+	return &(ux500_channel->channel);
+}
+
+static void ux500_dma_channel_release(struct dma_channel *channel)
+{
+	struct ux500_dma_channel *ux500_channel = channel->private_data;
+
+	DBG(7, "channel=%d\n", ux500_channel->ch_num);
+
+	if (ux500_channel->is_allocated) {
+		ux500_channel->is_allocated = 0;
+		channel->status = MUSB_DMA_STATUS_FREE;
+		channel->actual_len = 0;
+	}
+}
+
+static int ux500_dma_is_compatible(struct dma_channel *channel,
+		u16 maxpacket, void *buf, u32 length)
+{
+	if ((maxpacket & 0x3)		||
+		((int)buf & 0x3)	||
+		(length < 512)		||
+		(length & 0x3))
+		return false;
+	else
+		return true;
+}
+
+static int ux500_dma_channel_program(struct dma_channel *channel,
+				u16 packet_sz, u8 mode,
+				dma_addr_t dma_addr, u32 len)
+{
+	int ret;
+
+	BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
+		channel->status == MUSB_DMA_STATUS_BUSY);
+
+	if (!ux500_dma_is_compatible(channel, packet_sz, (void *)dma_addr, len))
+		return false;
+
+	channel->status = MUSB_DMA_STATUS_BUSY;
+	channel->actual_len = 0;
+	ret = ux500_configure_channel(channel, packet_sz, mode, dma_addr, len);
+	if (!ret)
+		channel->status = MUSB_DMA_STATUS_FREE;
+
+	return ret;
+}
+
+static int ux500_dma_channel_abort(struct dma_channel *channel)
+{
+	struct ux500_dma_channel *ux500_channel = channel->private_data;
+	struct ux500_dma_controller *controller = ux500_channel->controller;
+	struct musb *musb = controller->private_data;
+	void __iomem *epio = musb->endpoints[ux500_channel->hw_ep->epnum].regs;
+	u16 csr;
+
+	DBG(4, "channel=%d, is_tx=%d\n", ux500_channel->ch_num,
+						ux500_channel->is_tx);
+
+	if (channel->status == MUSB_DMA_STATUS_BUSY) {
+		if (ux500_channel->is_tx) {
+			csr = musb_readw(epio, MUSB_TXCSR);
+			csr &= ~(MUSB_TXCSR_AUTOSET |
+				 MUSB_TXCSR_DMAENAB |
+				 MUSB_TXCSR_DMAMODE);
+			musb_writew(epio, MUSB_TXCSR, csr);
+		} else {
+			csr = musb_readw(epio, MUSB_RXCSR);
+			csr &= ~(MUSB_RXCSR_AUTOCLEAR |
+				 MUSB_RXCSR_DMAENAB |
+				 MUSB_RXCSR_DMAMODE);
+			musb_writew(epio, MUSB_RXCSR, csr);
+		}
+
+		ux500_channel->dma_chan->device->
+				device_control(ux500_channel->dma_chan,
+					DMA_TERMINATE_ALL, 0);
+		channel->status = MUSB_DMA_STATUS_FREE;
+	}
+	return 0;
+}
+
+static int ux500_dma_controller_stop(struct dma_controller *c)
+{
+	struct ux500_dma_controller *controller = container_of(c,
+			struct ux500_dma_controller, controller);
+	struct ux500_dma_channel *ux500_channel;
+	struct dma_channel *channel;
+	u8 ch_num;
+
+	for (ch_num = 0; ch_num < controller->num_rx_channels; ch_num++) {
+		channel = &controller->rx_channel[ch_num].channel;
+		ux500_channel = channel->private_data;
+
+		ux500_dma_channel_release(channel);
+
+		if (ux500_channel->dma_chan)
+			dma_release_channel(ux500_channel->dma_chan);
+	}
+
+	for (ch_num = 0; ch_num < controller->num_tx_channels; ch_num++) {
+		channel = &controller->tx_channel[ch_num].channel;
+		ux500_channel = channel->private_data;
+
+		ux500_dma_channel_release(channel);
+
+		if (ux500_channel->dma_chan)
+			dma_release_channel(ux500_channel->dma_chan);
+	}
+
+	return 0;
+}
+
+static int ux500_dma_controller_start(struct dma_controller *c)
+{
+	struct ux500_dma_controller *controller = container_of(c,
+			struct ux500_dma_controller, controller);
+	struct ux500_dma_channel *ux500_channel = NULL;
+	struct musb *musb = controller->private_data;
+	struct device *dev = musb->controller;
+	struct musb_hdrc_platform_data *plat = dev->platform_data;
+	struct ux500_musb_board_data *data = plat->board_data;
+	struct dma_channel *dma_channel = NULL;
+	u32 ch_num;
+	u8 dir;
+	u8 is_tx = 0;
+
+	void **param_array;
+	struct ux500_dma_channel *channel_array;
+	u32 ch_count;
+	void (*musb_channel_work)(struct work_struct *);
+	dma_cap_mask_t mask;
+
+	if ((data->num_rx_channels > UX500_MUSB_DMA_NUM_RX_CHANNELS) ||
+		(data->num_tx_channels > UX500_MUSB_DMA_NUM_TX_CHANNELS))
+		return -EINVAL;
+
+	controller->num_rx_channels = data->num_rx_channels;
+	controller->num_tx_channels = data->num_tx_channels;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	/* Prepare the loop for RX channels */
+	channel_array = controller->rx_channel;
+	ch_count = data->num_rx_channels;
+	param_array = data->dma_rx_param_array;
+	musb_channel_work = ux500_rx_work;
+
+	for (dir = 0; dir < 2; dir++) {
+		for (ch_num = 0; ch_num < ch_count; ch_num++) {
+			ux500_channel = &channel_array[ch_num];
+			ux500_channel->controller = controller;
+			ux500_channel->ch_num = ch_num;
+			ux500_channel->is_tx = is_tx;
+
+			dma_channel = &(ux500_channel->channel);
+			dma_channel->private_data = ux500_channel;
+			dma_channel->status = MUSB_DMA_STATUS_FREE;
+			dma_channel->max_len = SZ_16M;
+
+			ux500_channel->dma_chan = dma_request_channel(mask,
+							data->dma_filter,
+							param_array[ch_num]);
+			if (!ux500_channel->dma_chan) {
+				ERR("Dma pipe allocation error dir=%d ch=%d\n",
+					dir, ch_num);
+
+				/* Release already allocated channels */
+				ux500_dma_controller_stop(c);
+
+				return -EBUSY;
+			}
+
+			INIT_WORK(&ux500_channel->channel_work,
+				musb_channel_work);
+		}
+
+		/* Prepare the loop for TX channels */
+		channel_array = controller->tx_channel;
+		ch_count = data->num_tx_channels;
+		param_array = data->dma_tx_param_array;
+		musb_channel_work = ux500_tx_work;
+		is_tx = 1;
+	}
+
+	return 0;
+}
+
+void dma_controller_destroy(struct dma_controller *c)
+{
+	struct ux500_dma_controller *controller = container_of(c,
+			struct ux500_dma_controller, controller);
+
+	kfree(controller);
+}
+
+struct dma_controller *__init
+dma_controller_create(struct musb *musb, void __iomem *base)
+{
+	struct ux500_dma_controller *controller;
+	struct platform_device *pdev = to_platform_device(musb->controller);
+	struct resource	*iomem;
+
+	controller = kzalloc(sizeof(*controller), GFP_KERNEL);
+	if (!controller)
+		return NULL;
+
+	controller->private_data = musb;
+
+	/* Save physical address for DMA controller. */
+	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	controller->phy_base = (dma_addr_t) iomem->start;
+
+	controller->controller.start = ux500_dma_controller_start;
+	controller->controller.stop = ux500_dma_controller_stop;
+	controller->controller.channel_alloc = ux500_dma_channel_allocate;
+	controller->controller.channel_release = ux500_dma_channel_release;
+	controller->controller.channel_program = ux500_dma_channel_program;
+	controller->controller.channel_abort = ux500_dma_channel_abort;
+	controller->controller.is_compatible = ux500_dma_is_compatible;
+
+	return &controller->controller;
+}