drivers/usb/musb/ux500_dma.c - maze/linux - Git at Google

 /*
  * drivers/usb/musb/ux500_dma.c
  *
  * U8500 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 <linux/sizes.h>
 #include <linux/platform_data/usb-musb-ux500.h>
 #include "musb_core.h"

 static const char *iep_chan_names[] = { "iep_1_9", "iep_2_10", "iep_3_11", "iep_4_12",
 					"iep_5_13", "iep_6_14", "iep_7_15", "iep_8" };
 static const char *oep_chan_names[] = { "oep_1_9", "oep_2_10", "oep_3_11", "oep_4_12",
 					"oep_5_13", "oep_6_14", "oep_7_15", "oep_8" };

 struct ux500_dma_channel {
 	struct dma_channel channel;
 	struct ux500_dma_controller *controller;
 	struct musb_hw_ep *hw_ep;
 	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_TX_CHANNELS];
 	struct ux500_dma_channel tx_channel[UX500_MUSB_DMA_NUM_RX_TX_CHANNELS];
 	void *private_data;
 	dma_addr_t phy_base;
 };

 /* Work function invoked from DMA callback to handle rx transfers. */
 static void ux500_dma_callback(void *private_data)
 {
 	struct dma_channel *channel = private_data;
 	struct ux500_dma_channel *ux500_channel = channel->private_data;
 	struct musb_hw_ep       *hw_ep = ux500_channel->hw_ep;
 	struct musb *musb = hw_ep->musb;
 	unsigned long flags;

 	dev_dbg(musb->controller, "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);

 }

 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_transfer_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);
 	struct musb *musb = ux500_channel->controller->private_data;

 	dev_dbg(musb->controller,
 		"packet_sz=%d, mode=%d, dma_addr=0x%llu, len=%d is_tx=%d\n",
 		packet_sz, mode, (unsigned long long) 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_MEM_TO_DEV : DMA_DEV_TO_MEM;
 	addr_width = (len & 0x3) ? DMA_SLAVE_BUSWIDTH_1_BYTE :
 					DMA_SLAVE_BUSWIDTH_4_BYTES;

 	slave_conf.direction = direction;
 	slave_conf.src_addr = usb_fifo_addr;
 	slave_conf.src_addr_width = addr_width;
 	slave_conf.src_maxburst = 16;
 	slave_conf.dst_addr = usb_fifo_addr;
 	slave_conf.dst_addr_width = addr_width;
 	slave_conf.dst_maxburst = 16;
 	slave_conf.device_fc = false;

 	dma_chan->device->device_control(dma_chan, DMA_SLAVE_CONFIG,
 					     (unsigned long) &slave_conf);

 	dma_desc = dmaengine_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;
 	struct musb *musb = controller->private_data;
 	u8 ch_num = hw_ep->epnum - 1;

 	/* 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;

 	if (ch_num >= UX500_MUSB_DMA_NUM_RX_TX_CHANNELS)
 		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;

 	dev_dbg(musb->controller, "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;
 	struct musb *musb = ux500_channel->controller->private_data;

 	dev_dbg(musb->controller, "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)		||
 		((unsigned long 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;

 	dev_dbg(musb->controller, "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 void ux500_dma_controller_stop(struct ux500_dma_controller *controller)
 {
 	struct ux500_dma_channel *ux500_channel;
 	struct dma_channel *channel;
 	u8 ch_num;

 	for (ch_num = 0; ch_num < UX500_MUSB_DMA_NUM_RX_TX_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 < UX500_MUSB_DMA_NUM_RX_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);
 	}
 }

 static int ux500_dma_controller_start(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_get_platdata(dev);
 	struct ux500_musb_board_data *data;
 	struct dma_channel *dma_channel = NULL;
 	char **chan_names;
 	u32 ch_num;
 	u8 dir;
 	u8 is_tx = 0;

 	void **param_array;
 	struct ux500_dma_channel *channel_array;
 	dma_cap_mask_t mask;

 	if (!plat) {
 		dev_err(musb->controller, "No platform data\n");
 		return -EINVAL;
 	}

 	data = plat->board_data;

 	dma_cap_zero(mask);
 	dma_cap_set(DMA_SLAVE, mask);

 	/* Prepare the loop for RX channels */
 	channel_array = controller->rx_channel;
 	param_array = data ? data->dma_rx_param_array : NULL;
 	chan_names = (char **)iep_chan_names;

 	for (dir = 0; dir < 2; dir++) {
 		for (ch_num = 0;
 		     ch_num < UX500_MUSB_DMA_NUM_RX_TX_CHANNELS;
 		     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_slave_channel(dev, chan_names[ch_num]);

 			if (!ux500_channel->dma_chan)
 				ux500_channel->dma_chan =
 					dma_request_channel(mask,
 							    data ?
 							    data->dma_filter :
 							    NULL,
 							    param_array ?
 							    param_array[ch_num] :
 							    NULL);

 			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(controller);

 				return -EBUSY;
 			}

 		}

 		/* Prepare the loop for TX channels */
 		channel_array = controller->tx_channel;
 		param_array = data ? data->dma_tx_param_array : NULL;
 		chan_names = (char **)oep_chan_names;
 		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);

 	ux500_dma_controller_stop(controller);
 	kfree(controller);
 }

 struct dma_controller *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;
 	int ret;

 	controller = kzalloc(sizeof(*controller), GFP_KERNEL);
 	if (!controller)
 		goto kzalloc_fail;

 	controller->private_data = musb;

 	/* Save physical address for DMA controller. */
 	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!iomem) {
 		dev_err(musb->controller, "no memory resource defined\n");
 		goto plat_get_fail;
 	}

 	controller->phy_base = (dma_addr_t) iomem->start;

 	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;

 	ret = ux500_dma_controller_start(controller);
 	if (ret)
 		goto plat_get_fail;
 	return &controller->controller;

 plat_get_fail:
 	kfree(controller);
 kzalloc_fail:
 	return NULL;
 }
	/*
	* drivers/usb/musb/ux500_dma.c
	*
	* U8500 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 <linux/sizes.h>
	#include <linux/platform_data/usb-musb-ux500.h>
	#include "musb_core.h"

	static const char *iep_chan_names[] = { "iep_1_9", "iep_2_10", "iep_3_11", "iep_4_12",
	"iep_5_13", "iep_6_14", "iep_7_15", "iep_8" };
	static const char *oep_chan_names[] = { "oep_1_9", "oep_2_10", "oep_3_11", "oep_4_12",
	"oep_5_13", "oep_6_14", "oep_7_15", "oep_8" };

	struct ux500_dma_channel {
	struct dma_channel channel;
	struct ux500_dma_controller *controller;
	struct musb_hw_ep *hw_ep;
	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_TX_CHANNELS];
	struct ux500_dma_channel tx_channel[UX500_MUSB_DMA_NUM_RX_TX_CHANNELS];
	void *private_data;
	dma_addr_t phy_base;
	};

	/* Work function invoked from DMA callback to handle rx transfers. */
	static void ux500_dma_callback(void *private_data)
	{
	struct dma_channel *channel = private_data;
	struct ux500_dma_channel *ux500_channel = channel->private_data;
	struct musb_hw_ep *hw_ep = ux500_channel->hw_ep;
	struct musb *musb = hw_ep->musb;
	unsigned long flags;

	dev_dbg(musb->controller, "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);

	}

	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_transfer_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);
	struct musb *musb = ux500_channel->controller->private_data;

	dev_dbg(musb->controller,
	"packet_sz=%d, mode=%d, dma_addr=0x%llu, len=%d is_tx=%d\n",
	packet_sz, mode, (unsigned long long) 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_MEM_TO_DEV : DMA_DEV_TO_MEM;
	addr_width = (len & 0x3) ? DMA_SLAVE_BUSWIDTH_1_BYTE :
	DMA_SLAVE_BUSWIDTH_4_BYTES;

	slave_conf.direction = direction;
	slave_conf.src_addr = usb_fifo_addr;
	slave_conf.src_addr_width = addr_width;
	slave_conf.src_maxburst = 16;
	slave_conf.dst_addr = usb_fifo_addr;
	slave_conf.dst_addr_width = addr_width;
	slave_conf.dst_maxburst = 16;
	slave_conf.device_fc = false;

	dma_chan->device->device_control(dma_chan, DMA_SLAVE_CONFIG,
	(unsigned long) &slave_conf);

	dma_desc = dmaengine_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;
	struct musb *musb = controller->private_data;
	u8 ch_num = hw_ep->epnum - 1;

	/* 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;

	if (ch_num >= UX500_MUSB_DMA_NUM_RX_TX_CHANNELS)
	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;

	dev_dbg(musb->controller, "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;
	struct musb *musb = ux500_channel->controller->private_data;

	dev_dbg(musb->controller, "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) \|\|
	((unsigned long 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;

	dev_dbg(musb->controller, "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 void ux500_dma_controller_stop(struct ux500_dma_controller *controller)
	{
	struct ux500_dma_channel *ux500_channel;
	struct dma_channel *channel;
	u8 ch_num;

	for (ch_num = 0; ch_num < UX500_MUSB_DMA_NUM_RX_TX_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 < UX500_MUSB_DMA_NUM_RX_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);
	}
	}

	static int ux500_dma_controller_start(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_get_platdata(dev);
	struct ux500_musb_board_data *data;
	struct dma_channel *dma_channel = NULL;
	char **chan_names;
	u32 ch_num;
	u8 dir;
	u8 is_tx = 0;

	void **param_array;
	struct ux500_dma_channel *channel_array;
	dma_cap_mask_t mask;

	if (!plat) {
	dev_err(musb->controller, "No platform data\n");
	return -EINVAL;
	}

	data = plat->board_data;

	dma_cap_zero(mask);
	dma_cap_set(DMA_SLAVE, mask);

	/* Prepare the loop for RX channels */
	channel_array = controller->rx_channel;
	param_array = data ? data->dma_rx_param_array : NULL;
	chan_names = (char **)iep_chan_names;

	for (dir = 0; dir < 2; dir++) {
	for (ch_num = 0;
	ch_num < UX500_MUSB_DMA_NUM_RX_TX_CHANNELS;
	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_slave_channel(dev, chan_names[ch_num]);

	if (!ux500_channel->dma_chan)
	ux500_channel->dma_chan =
	dma_request_channel(mask,
	data ?
	data->dma_filter :
	NULL,
	param_array ?
	param_array[ch_num] :
	NULL);

	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(controller);

	return -EBUSY;
	}

	}

	/* Prepare the loop for TX channels */
	channel_array = controller->tx_channel;
	param_array = data ? data->dma_tx_param_array : NULL;
	chan_names = (char **)oep_chan_names;
	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);

	ux500_dma_controller_stop(controller);
	kfree(controller);
	}

	struct dma_controller 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;
	int ret;

	controller = kzalloc(sizeof(*controller), GFP_KERNEL);
	if (!controller)
	goto kzalloc_fail;

	controller->private_data = musb;

	/* Save physical address for DMA controller. */
	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!iomem) {
	dev_err(musb->controller, "no memory resource defined\n");
	goto plat_get_fail;
	}

	controller->phy_base = (dma_addr_t) iomem->start;

	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;

	ret = ux500_dma_controller_start(controller);
	if (ret)
	goto plat_get_fail;
	return &controller->controller;

	plat_get_fail:
	kfree(controller);
	kzalloc_fail:
	return NULL;
	}