drivers/usb/musb/musbhsdma.c - linux - Git at Google

 /*
  * MUSB OTG driver - support for Mentor's DMA controller
  *
  * Copyright 2005 Mentor Graphics Corporation
  * Copyright (C) 2005-2007 by Texas Instruments
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * version 2 as published by the Free Software Foundation.
  *
  * 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, write to the Free Software
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  * 02110-1301 USA
  *
  * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
  * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  */
 #include <linux/device.h>
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
 #include "musb_core.h"
 #include "musbhsdma.h"

 static int dma_controller_start(struct dma_controller *c)
 {
 	/* nothing to do */
 	return 0;
 }

 static void dma_channel_release(struct dma_channel *channel);

 static int dma_controller_stop(struct dma_controller *c)
 {
 	struct musb_dma_controller *controller = container_of(c,
 			struct musb_dma_controller, controller);
 	struct musb *musb = controller->private_data;
 	struct dma_channel *channel;
 	u8 bit;

 	if (controller->used_channels != 0) {
 		dev_err(musb->controller,
 			"Stopping DMA controller while channel active\n");

 		for (bit = 0; bit < MUSB_HSDMA_CHANNELS; bit++) {
 			if (controller->used_channels & (1 << bit)) {
 				channel = &controller->channel[bit].channel;
 				dma_channel_release(channel);

 				if (!controller->used_channels)
 					break;
 			}
 		}
 	}

 	return 0;
 }

 static struct dma_channel *dma_channel_allocate(struct dma_controller *c,
 				struct musb_hw_ep *hw_ep, u8 transmit)
 {
 	struct musb_dma_controller *controller = container_of(c,
 			struct musb_dma_controller, controller);
 	struct musb_dma_channel *musb_channel = NULL;
 	struct dma_channel *channel = NULL;
 	u8 bit;

 	for (bit = 0; bit < MUSB_HSDMA_CHANNELS; bit++) {
 		if (!(controller->used_channels & (1 << bit))) {
 			controller->used_channels |= (1 << bit);
 			musb_channel = &(controller->channel[bit]);
 			musb_channel->controller = controller;
 			musb_channel->idx = bit;
 			musb_channel->epnum = hw_ep->epnum;
 			musb_channel->transmit = transmit;
 			channel = &(musb_channel->channel);
 			channel->private_data = musb_channel;
 			channel->status = MUSB_DMA_STATUS_FREE;
 			channel->max_len = 0x10000;
 			/* Tx => mode 1; Rx => mode 0 */
 			channel->desired_mode = transmit;
 			channel->actual_len = 0;
 			break;
 		}
 	}

 	return channel;
 }

 static void dma_channel_release(struct dma_channel *channel)
 {
 	struct musb_dma_channel *musb_channel = channel->private_data;

 	channel->actual_len = 0;
 	musb_channel->start_addr = 0;
 	musb_channel->len = 0;

 	musb_channel->controller->used_channels &=
 		~(1 << musb_channel->idx);

 	channel->status = MUSB_DMA_STATUS_UNKNOWN;
 }

 static void configure_channel(struct dma_channel *channel,
 				u16 packet_sz, u8 mode,
 				dma_addr_t dma_addr, u32 len)
 {
 	struct musb_dma_channel *musb_channel = channel->private_data;
 	struct musb_dma_controller *controller = musb_channel->controller;
 	void __iomem *mbase = controller->base;
 	u8 bchannel = musb_channel->idx;
 	u16 csr = 0;

 	DBG(4, "%p, pkt_sz %d, addr 0x%x, len %d, mode %d\n",
 			channel, packet_sz, dma_addr, len, mode);

 	if (mode) {
 		csr |= 1 << MUSB_HSDMA_MODE1_SHIFT;
 		BUG_ON(len < packet_sz);

 		if (packet_sz >= 64) {
 			csr |= MUSB_HSDMA_BURSTMODE_INCR16
 					<< MUSB_HSDMA_BURSTMODE_SHIFT;
 		} else if (packet_sz >= 32) {
 			csr |= MUSB_HSDMA_BURSTMODE_INCR8
 					<< MUSB_HSDMA_BURSTMODE_SHIFT;
 		} else if (packet_sz >= 16) {
 			csr |= MUSB_HSDMA_BURSTMODE_INCR4
 					<< MUSB_HSDMA_BURSTMODE_SHIFT;
 		}
 	}

 	csr |= (musb_channel->epnum << MUSB_HSDMA_ENDPOINT_SHIFT)
 		| (1 << MUSB_HSDMA_ENABLE_SHIFT)
 		| (1 << MUSB_HSDMA_IRQENABLE_SHIFT)
 		| (musb_channel->transmit
 				? (1 << MUSB_HSDMA_TRANSMIT_SHIFT)
 				: 0);

 	/* address/count */
 	musb_write_hsdma_addr(mbase, bchannel, dma_addr);
 	musb_write_hsdma_count(mbase, bchannel, len);

 	/* control (this should start things) */
 	musb_writew(mbase,
 		MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_CONTROL),
 		csr);
 }

 static int dma_channel_program(struct dma_channel *channel,
 				u16 packet_sz, u8 mode,
 				dma_addr_t dma_addr, u32 len)
 {
 	struct musb_dma_channel *musb_channel = channel->private_data;

 	DBG(2, "ep%d-%s pkt_sz %d, dma_addr 0x%x length %d, mode %d\n",
 		musb_channel->epnum,
 		musb_channel->transmit ? "Tx" : "Rx",
 		packet_sz, dma_addr, len, mode);

 	BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
 		channel->status == MUSB_DMA_STATUS_BUSY);

 	channel->actual_len = 0;
 	musb_channel->start_addr = dma_addr;
 	musb_channel->len = len;
 	musb_channel->max_packet_sz = packet_sz;
 	channel->status = MUSB_DMA_STATUS_BUSY;

 	if ((mode == 1) && (len >= packet_sz))
 		configure_channel(channel, packet_sz, 1, dma_addr, len);
 	else
 		configure_channel(channel, packet_sz, 0, dma_addr, len);

 	return true;
 }

 static int dma_channel_abort(struct dma_channel *channel)
 {
 	struct musb_dma_channel *musb_channel = channel->private_data;
 	void __iomem *mbase = musb_channel->controller->base;

 	u8 bchannel = musb_channel->idx;
 	int offset;
 	u16 csr;

 	if (channel->status == MUSB_DMA_STATUS_BUSY) {
 		if (musb_channel->transmit) {
 			offset = MUSB_EP_OFFSET(musb_channel->epnum,
 						MUSB_TXCSR);

 			/*
 			 * The programming guide says that we must clear
 			 * the DMAENAB bit before the DMAMODE bit...
 			 */
 			csr = musb_readw(mbase, offset);
 			csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB);
 			musb_writew(mbase, offset, csr);
 			csr &= ~MUSB_TXCSR_DMAMODE;
 			musb_writew(mbase, offset, csr);
 		} else {
 			offset = MUSB_EP_OFFSET(musb_channel->epnum,
 						MUSB_RXCSR);

 			csr = musb_readw(mbase, offset);
 			csr &= ~(MUSB_RXCSR_AUTOCLEAR |
 				 MUSB_RXCSR_DMAENAB |
 				 MUSB_RXCSR_DMAMODE);
 			musb_writew(mbase, offset, csr);
 		}

 		musb_writew(mbase,
 			MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_CONTROL),
 			0);
 		musb_write_hsdma_addr(mbase, bchannel, 0);
 		musb_write_hsdma_count(mbase, bchannel, 0);
 		channel->status = MUSB_DMA_STATUS_FREE;
 	}

 	return 0;
 }

 static irqreturn_t dma_controller_irq(int irq, void *private_data)
 {
 	struct musb_dma_controller *controller = private_data;
 	struct musb *musb = controller->private_data;
 	struct musb_dma_channel *musb_channel;
 	struct dma_channel *channel;

 	void __iomem *mbase = controller->base;

 	irqreturn_t retval = IRQ_NONE;

 	unsigned long flags;

 	u8 bchannel;
 	u8 int_hsdma;

 	u32 addr;
 	u16 csr;

 	spin_lock_irqsave(&musb->lock, flags);

 	int_hsdma = musb_readb(mbase, MUSB_HSDMA_INTR);
 	if (!int_hsdma)
 		goto done;

 	for (bchannel = 0; bchannel < MUSB_HSDMA_CHANNELS; bchannel++) {
 		if (int_hsdma & (1 << bchannel)) {
 			musb_channel = (struct musb_dma_channel *)
 					&(controller->channel[bchannel]);
 			channel = &musb_channel->channel;

 			csr = musb_readw(mbase,
 					MUSB_HSDMA_CHANNEL_OFFSET(bchannel,
 							MUSB_HSDMA_CONTROL));

 			if (csr & (1 << MUSB_HSDMA_BUSERROR_SHIFT)) {
 				musb_channel->channel.status =
 					MUSB_DMA_STATUS_BUS_ABORT;
 			} else {
 				u8 devctl;

 				addr = musb_read_hsdma_addr(mbase,
 						bchannel);
 				channel->actual_len = addr
 					- musb_channel->start_addr;

 				DBG(2, "ch %p, 0x%x -> 0x%x (%d / %d) %s\n",
 					channel, musb_channel->start_addr,
 					addr, channel->actual_len,
 					musb_channel->len,
 					(channel->actual_len
 						< musb_channel->len) ?
 					"=> reconfig 0" : "=> complete");

 				devctl = musb_readb(mbase, MUSB_DEVCTL);

 				channel->status = MUSB_DMA_STATUS_FREE;

 				/* completed */
 				if ((devctl & MUSB_DEVCTL_HM)
 					&& (musb_channel->transmit)
 					&& ((channel->desired_mode == 0)
 					    || (channel->actual_len &
 					    (musb_channel->max_packet_sz - 1)))
 				    ) {
 					u8  epnum  = musb_channel->epnum;
 					int offset = MUSB_EP_OFFSET(epnum,
 								    MUSB_TXCSR);
 					u16 txcsr;

 					/*
 					 * The programming guide says that we
 					 * must clear DMAENAB before DMAMODE.
 					 */
 					musb_ep_select(mbase, epnum);
 					txcsr = musb_readw(mbase, offset);
 					txcsr &= ~(MUSB_TXCSR_DMAENAB
 							| MUSB_TXCSR_AUTOSET);
 					musb_writew(mbase, offset, txcsr);
 					/* Send out the packet */
 					txcsr &= ~MUSB_TXCSR_DMAMODE;
 					txcsr |=  MUSB_TXCSR_TXPKTRDY;
 					musb_writew(mbase, offset, txcsr);
 				}
 				musb_dma_completion(musb, musb_channel->epnum,
 						    musb_channel->transmit);
 			}
 		}
 	}

 #ifdef CONFIG_BLACKFIN
 	/* Clear DMA interrup flags */
 	musb_writeb(mbase, MUSB_HSDMA_INTR, int_hsdma);
 #endif

 	retval = IRQ_HANDLED;
 done:
 	spin_unlock_irqrestore(&musb->lock, flags);
 	return retval;
 }

 void dma_controller_destroy(struct dma_controller *c)
 {
 	struct musb_dma_controller *controller = container_of(c,
 			struct musb_dma_controller, controller);

 	if (!controller)
 		return;

 	if (controller->irq)
 		free_irq(controller->irq, c);

 	kfree(controller);
 }

 struct dma_controller *__init
 dma_controller_create(struct musb *musb, void __iomem *base)
 {
 	struct musb_dma_controller *controller;
 	struct device *dev = musb->controller;
 	struct platform_device *pdev = to_platform_device(dev);
 	int irq = platform_get_irq(pdev, 1);

 	if (irq == 0) {
 		dev_err(dev, "No DMA interrupt line!\n");
 		return NULL;
 	}

 	controller = kzalloc(sizeof(*controller), GFP_KERNEL);
 	if (!controller)
 		return NULL;

 	controller->channel_count = MUSB_HSDMA_CHANNELS;
 	controller->private_data = musb;
 	controller->base = base;

 	controller->controller.start = dma_controller_start;
 	controller->controller.stop = dma_controller_stop;
 	controller->controller.channel_alloc = dma_channel_allocate;
 	controller->controller.channel_release = dma_channel_release;
 	controller->controller.channel_program = dma_channel_program;
 	controller->controller.channel_abort = dma_channel_abort;

 	if (request_irq(irq, dma_controller_irq, IRQF_DISABLED,
 			dev_name(musb->controller), &controller->controller)) {
 		dev_err(dev, "request_irq %d failed!\n", irq);
 		dma_controller_destroy(&controller->controller);

 		return NULL;
 	}

 	controller->irq = irq;

 	return &controller->controller;
 }
	/*
	* MUSB OTG driver - support for Mentor's DMA controller
	*
	* Copyright 2005 Mentor Graphics Corporation
	* Copyright (C) 2005-2007 by Texas Instruments
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* version 2 as published by the Free Software Foundation.
	*
	* 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, write to the Free Software
	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
	* 02110-1301 USA
	*
	* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
	* NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
	* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
	* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*
	*/
	#include <linux/device.h>
	#include <linux/interrupt.h>
	#include <linux/platform_device.h>
	#include "musb_core.h"
	#include "musbhsdma.h"

	static int dma_controller_start(struct dma_controller *c)
	{
	/* nothing to do */
	return 0;
	}

	static void dma_channel_release(struct dma_channel *channel);

	static int dma_controller_stop(struct dma_controller *c)
	{
	struct musb_dma_controller *controller = container_of(c,
	struct musb_dma_controller, controller);
	struct musb *musb = controller->private_data;
	struct dma_channel *channel;
	u8 bit;

	if (controller->used_channels != 0) {
	dev_err(musb->controller,
	"Stopping DMA controller while channel active\n");

	for (bit = 0; bit < MUSB_HSDMA_CHANNELS; bit++) {
	if (controller->used_channels & (1 << bit)) {
	channel = &controller->channel[bit].channel;
	dma_channel_release(channel);

	if (!controller->used_channels)
	break;
	}
	}
	}

	return 0;
	}

	static struct dma_channel dma_channel_allocate(struct dma_controller c,
	struct musb_hw_ep *hw_ep, u8 transmit)
	{
	struct musb_dma_controller *controller = container_of(c,
	struct musb_dma_controller, controller);
	struct musb_dma_channel *musb_channel = NULL;
	struct dma_channel *channel = NULL;
	u8 bit;

	for (bit = 0; bit < MUSB_HSDMA_CHANNELS; bit++) {
	if (!(controller->used_channels & (1 << bit))) {
	controller->used_channels \|= (1 << bit);
	musb_channel = &(controller->channel[bit]);
	musb_channel->controller = controller;
	musb_channel->idx = bit;
	musb_channel->epnum = hw_ep->epnum;
	musb_channel->transmit = transmit;
	channel = &(musb_channel->channel);
	channel->private_data = musb_channel;
	channel->status = MUSB_DMA_STATUS_FREE;
	channel->max_len = 0x10000;
	/* Tx => mode 1; Rx => mode 0 */
	channel->desired_mode = transmit;
	channel->actual_len = 0;
	break;
	}
	}

	return channel;
	}

	static void dma_channel_release(struct dma_channel *channel)
	{
	struct musb_dma_channel *musb_channel = channel->private_data;

	channel->actual_len = 0;
	musb_channel->start_addr = 0;
	musb_channel->len = 0;

	musb_channel->controller->used_channels &=
	~(1 << musb_channel->idx);

	channel->status = MUSB_DMA_STATUS_UNKNOWN;
	}

	static void configure_channel(struct dma_channel *channel,
	u16 packet_sz, u8 mode,
	dma_addr_t dma_addr, u32 len)
	{
	struct musb_dma_channel *musb_channel = channel->private_data;
	struct musb_dma_controller *controller = musb_channel->controller;
	void __iomem *mbase = controller->base;
	u8 bchannel = musb_channel->idx;
	u16 csr = 0;

	DBG(4, "%p, pkt_sz %d, addr 0x%x, len %d, mode %d\n",
	channel, packet_sz, dma_addr, len, mode);

	if (mode) {
	csr \|= 1 << MUSB_HSDMA_MODE1_SHIFT;
	BUG_ON(len < packet_sz);

	if (packet_sz >= 64) {
	csr \|= MUSB_HSDMA_BURSTMODE_INCR16
	<< MUSB_HSDMA_BURSTMODE_SHIFT;
	} else if (packet_sz >= 32) {
	csr \|= MUSB_HSDMA_BURSTMODE_INCR8
	<< MUSB_HSDMA_BURSTMODE_SHIFT;
	} else if (packet_sz >= 16) {
	csr \|= MUSB_HSDMA_BURSTMODE_INCR4
	<< MUSB_HSDMA_BURSTMODE_SHIFT;
	}
	}

	csr \|= (musb_channel->epnum << MUSB_HSDMA_ENDPOINT_SHIFT)
	\| (1 << MUSB_HSDMA_ENABLE_SHIFT)
	\| (1 << MUSB_HSDMA_IRQENABLE_SHIFT)
	\| (musb_channel->transmit
	? (1 << MUSB_HSDMA_TRANSMIT_SHIFT)
	: 0);

	/* address/count */
	musb_write_hsdma_addr(mbase, bchannel, dma_addr);
	musb_write_hsdma_count(mbase, bchannel, len);

	/* control (this should start things) */
	musb_writew(mbase,
	MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_CONTROL),
	csr);
	}

	static int dma_channel_program(struct dma_channel *channel,
	u16 packet_sz, u8 mode,
	dma_addr_t dma_addr, u32 len)
	{
	struct musb_dma_channel *musb_channel = channel->private_data;

	DBG(2, "ep%d-%s pkt_sz %d, dma_addr 0x%x length %d, mode %d\n",
	musb_channel->epnum,
	musb_channel->transmit ? "Tx" : "Rx",
	packet_sz, dma_addr, len, mode);

	BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN \|\|
	channel->status == MUSB_DMA_STATUS_BUSY);

	channel->actual_len = 0;
	musb_channel->start_addr = dma_addr;
	musb_channel->len = len;
	musb_channel->max_packet_sz = packet_sz;
	channel->status = MUSB_DMA_STATUS_BUSY;

	if ((mode == 1) && (len >= packet_sz))
	configure_channel(channel, packet_sz, 1, dma_addr, len);
	else
	configure_channel(channel, packet_sz, 0, dma_addr, len);

	return true;
	}

	static int dma_channel_abort(struct dma_channel *channel)
	{
	struct musb_dma_channel *musb_channel = channel->private_data;
	void __iomem *mbase = musb_channel->controller->base;

	u8 bchannel = musb_channel->idx;
	int offset;
	u16 csr;

	if (channel->status == MUSB_DMA_STATUS_BUSY) {
	if (musb_channel->transmit) {
	offset = MUSB_EP_OFFSET(musb_channel->epnum,
	MUSB_TXCSR);

	/*
	* The programming guide says that we must clear
	* the DMAENAB bit before the DMAMODE bit...
	*/
	csr = musb_readw(mbase, offset);
	csr &= ~(MUSB_TXCSR_AUTOSET \| MUSB_TXCSR_DMAENAB);
	musb_writew(mbase, offset, csr);
	csr &= ~MUSB_TXCSR_DMAMODE;
	musb_writew(mbase, offset, csr);
	} else {
	offset = MUSB_EP_OFFSET(musb_channel->epnum,
	MUSB_RXCSR);

	csr = musb_readw(mbase, offset);
	csr &= ~(MUSB_RXCSR_AUTOCLEAR \|
	MUSB_RXCSR_DMAENAB \|
	MUSB_RXCSR_DMAMODE);
	musb_writew(mbase, offset, csr);
	}

	musb_writew(mbase,
	MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_CONTROL),
	0);
	musb_write_hsdma_addr(mbase, bchannel, 0);
	musb_write_hsdma_count(mbase, bchannel, 0);
	channel->status = MUSB_DMA_STATUS_FREE;
	}

	return 0;
	}

	static irqreturn_t dma_controller_irq(int irq, void *private_data)
	{
	struct musb_dma_controller *controller = private_data;
	struct musb *musb = controller->private_data;
	struct musb_dma_channel *musb_channel;
	struct dma_channel *channel;

	void __iomem *mbase = controller->base;

	irqreturn_t retval = IRQ_NONE;

	unsigned long flags;

	u8 bchannel;
	u8 int_hsdma;

	u32 addr;
	u16 csr;

	spin_lock_irqsave(&musb->lock, flags);

	int_hsdma = musb_readb(mbase, MUSB_HSDMA_INTR);
	if (!int_hsdma)
	goto done;

	for (bchannel = 0; bchannel < MUSB_HSDMA_CHANNELS; bchannel++) {
	if (int_hsdma & (1 << bchannel)) {
	musb_channel = (struct musb_dma_channel *)
	&(controller->channel[bchannel]);
	channel = &musb_channel->channel;

	csr = musb_readw(mbase,
	MUSB_HSDMA_CHANNEL_OFFSET(bchannel,
	MUSB_HSDMA_CONTROL));

	if (csr & (1 << MUSB_HSDMA_BUSERROR_SHIFT)) {
	musb_channel->channel.status =
	MUSB_DMA_STATUS_BUS_ABORT;
	} else {
	u8 devctl;

	addr = musb_read_hsdma_addr(mbase,
	bchannel);
	channel->actual_len = addr
	- musb_channel->start_addr;

	DBG(2, "ch %p, 0x%x -> 0x%x (%d / %d) %s\n",
	channel, musb_channel->start_addr,
	addr, channel->actual_len,
	musb_channel->len,
	(channel->actual_len
	< musb_channel->len) ?
	"=> reconfig 0" : "=> complete");

	devctl = musb_readb(mbase, MUSB_DEVCTL);

	channel->status = MUSB_DMA_STATUS_FREE;

	/* completed */
	if ((devctl & MUSB_DEVCTL_HM)
	&& (musb_channel->transmit)
	&& ((channel->desired_mode == 0)
	\|\| (channel->actual_len &
	(musb_channel->max_packet_sz - 1)))
	) {
	u8 epnum = musb_channel->epnum;
	int offset = MUSB_EP_OFFSET(epnum,
	MUSB_TXCSR);
	u16 txcsr;

	/*
	* The programming guide says that we
	* must clear DMAENAB before DMAMODE.
	*/
	musb_ep_select(mbase, epnum);
	txcsr = musb_readw(mbase, offset);
	txcsr &= ~(MUSB_TXCSR_DMAENAB
	\| MUSB_TXCSR_AUTOSET);
	musb_writew(mbase, offset, txcsr);
	/* Send out the packet */
	txcsr &= ~MUSB_TXCSR_DMAMODE;
	txcsr \|= MUSB_TXCSR_TXPKTRDY;
	musb_writew(mbase, offset, txcsr);
	}
	musb_dma_completion(musb, musb_channel->epnum,
	musb_channel->transmit);
	}
	}
	}

	#ifdef CONFIG_BLACKFIN
	/* Clear DMA interrup flags */
	musb_writeb(mbase, MUSB_HSDMA_INTR, int_hsdma);
	#endif

	retval = IRQ_HANDLED;
	done:
	spin_unlock_irqrestore(&musb->lock, flags);
	return retval;
	}

	void dma_controller_destroy(struct dma_controller *c)
	{
	struct musb_dma_controller *controller = container_of(c,
	struct musb_dma_controller, controller);

	if (!controller)
	return;

	if (controller->irq)
	free_irq(controller->irq, c);

	kfree(controller);
	}

	struct dma_controller *__init
	dma_controller_create(struct musb musb, void __iomem base)
	{
	struct musb_dma_controller *controller;
	struct device *dev = musb->controller;
	struct platform_device *pdev = to_platform_device(dev);
	int irq = platform_get_irq(pdev, 1);

	if (irq == 0) {
	dev_err(dev, "No DMA interrupt line!\n");
	return NULL;
	}

	controller = kzalloc(sizeof(*controller), GFP_KERNEL);
	if (!controller)
	return NULL;

	controller->channel_count = MUSB_HSDMA_CHANNELS;
	controller->private_data = musb;
	controller->base = base;

	controller->controller.start = dma_controller_start;
	controller->controller.stop = dma_controller_stop;
	controller->controller.channel_alloc = dma_channel_allocate;
	controller->controller.channel_release = dma_channel_release;
	controller->controller.channel_program = dma_channel_program;
	controller->controller.channel_abort = dma_channel_abort;

	if (request_irq(irq, dma_controller_irq, IRQF_DISABLED,
	dev_name(musb->controller), &controller->controller)) {
	dev_err(dev, "request_irq %d failed!\n", irq);
	dma_controller_destroy(&controller->controller);

	return NULL;
	}

	controller->irq = irq;

	return &controller->controller;
	}