[linux-2.6-block.git] / drivers / mmc / host / tmio_mmc_dma.c

/*
 * linux/drivers/mmc/tmio_mmc_dma.c
 *
 * Copyright (C) 2010-2011 Guennadi Liakhovetski
 *
 * 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.
 *
 * DMA function for TMIO MMC implementations
 */

#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/mfd/tmio.h>
#include <linux/mmc/host.h>
#include <linux/mmc/tmio.h>
#include <linux/pagemap.h>
#include <linux/scatterlist.h>

#include "tmio_mmc.h"

#define TMIO_MMC_MIN_DMA_LEN 8

void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
{
	if (!host->chan_tx || !host->chan_rx)
		return;

	if (host->dma->enable)
		host->dma->enable(host, enable);
}

void tmio_mmc_abort_dma(struct tmio_mmc_host *host)
{
	tmio_mmc_enable_dma(host, false);

	if (host->chan_rx)
		dmaengine_terminate_all(host->chan_rx);
	if (host->chan_tx)
		dmaengine_terminate_all(host->chan_tx);

	tmio_mmc_enable_dma(host, true);
}

static void tmio_mmc_start_dma_rx(struct tmio_mmc_host *host)
{
	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
	struct dma_async_tx_descriptor *desc = NULL;
	struct dma_chan *chan = host->chan_rx;
	dma_cookie_t cookie;
	int ret, i;
	bool aligned = true, multiple = true;
	unsigned int align = (1 << host->pdata->alignment_shift) - 1;

	for_each_sg(sg, sg_tmp, host->sg_len, i) {
		if (sg_tmp->offset & align)
			aligned = false;
		if (sg_tmp->length & align) {
			multiple = false;
			break;
		}
	}

	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_SIZE ||
			  (align & PAGE_MASK))) || !multiple) {
		ret = -EINVAL;
		goto pio;
	}

	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
		host->force_pio = true;
		return;
	}

	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_RXRDY);

	/* The only sg element can be unaligned, use our bounce buffer then */
	if (!aligned) {
		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
		host->sg_ptr = &host->bounce_sg;
		sg = host->sg_ptr;
	}

	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_FROM_DEVICE);
	if (ret > 0)
		desc = dmaengine_prep_slave_sg(chan, sg, ret,
			DMA_DEV_TO_MEM, DMA_CTRL_ACK);

	if (desc) {
		cookie = dmaengine_submit(desc);
		if (cookie < 0) {
			desc = NULL;
			ret = cookie;
		}
	}
pio:
	if (!desc) {
		/* DMA failed, fall back to PIO */
		tmio_mmc_enable_dma(host, false);
		if (ret >= 0)
			ret = -EIO;
		host->chan_rx = NULL;
		dma_release_channel(chan);
		/* Free the Tx channel too */
		chan = host->chan_tx;
		if (chan) {
			host->chan_tx = NULL;
			dma_release_channel(chan);
		}
		dev_warn(&host->pdev->dev,
			 "DMA failed: %d, falling back to PIO\n", ret);
	}
}

static void tmio_mmc_start_dma_tx(struct tmio_mmc_host *host)
{
	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
	struct dma_async_tx_descriptor *desc = NULL;
	struct dma_chan *chan = host->chan_tx;
	dma_cookie_t cookie;
	int ret, i;
	bool aligned = true, multiple = true;
	unsigned int align = (1 << host->pdata->alignment_shift) - 1;

	for_each_sg(sg, sg_tmp, host->sg_len, i) {
		if (sg_tmp->offset & align)
			aligned = false;
		if (sg_tmp->length & align) {
			multiple = false;
			break;
		}
	}

	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_SIZE ||
			  (align & PAGE_MASK))) || !multiple) {
		ret = -EINVAL;
		goto pio;
	}

	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
		host->force_pio = true;
		return;
	}

	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_TXRQ);

	/* The only sg element can be unaligned, use our bounce buffer then */
	if (!aligned) {
		unsigned long flags;
		void *sg_vaddr = tmio_mmc_kmap_atomic(sg, &flags);
		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
		memcpy(host->bounce_buf, sg_vaddr, host->bounce_sg.length);
		tmio_mmc_kunmap_atomic(sg, &flags, sg_vaddr);
		host->sg_ptr = &host->bounce_sg;
		sg = host->sg_ptr;
	}

	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_TO_DEVICE);
	if (ret > 0)
		desc = dmaengine_prep_slave_sg(chan, sg, ret,
			DMA_MEM_TO_DEV, DMA_CTRL_ACK);

	if (desc) {
		cookie = dmaengine_submit(desc);
		if (cookie < 0) {
			desc = NULL;
			ret = cookie;
		}
	}
pio:
	if (!desc) {
		/* DMA failed, fall back to PIO */
		tmio_mmc_enable_dma(host, false);
		if (ret >= 0)
			ret = -EIO;
		host->chan_tx = NULL;
		dma_release_channel(chan);
		/* Free the Rx channel too */
		chan = host->chan_rx;
		if (chan) {
			host->chan_rx = NULL;
			dma_release_channel(chan);
		}
		dev_warn(&host->pdev->dev,
			 "DMA failed: %d, falling back to PIO\n", ret);
	}
}

void tmio_mmc_start_dma(struct tmio_mmc_host *host,
			       struct mmc_data *data)
{
	if (data->flags & MMC_DATA_READ) {
		if (host->chan_rx)
			tmio_mmc_start_dma_rx(host);
	} else {
		if (host->chan_tx)
			tmio_mmc_start_dma_tx(host);
	}
}

static void tmio_mmc_issue_tasklet_fn(unsigned long priv)
{
	struct tmio_mmc_host *host = (struct tmio_mmc_host *)priv;
	struct dma_chan *chan = NULL;

	spin_lock_irq(&host->lock);

	if (host && host->data) {
		if (host->data->flags & MMC_DATA_READ)
			chan = host->chan_rx;
		else
			chan = host->chan_tx;
	}

	spin_unlock_irq(&host->lock);

	tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);

	if (chan)
		dma_async_issue_pending(chan);
}

static void tmio_mmc_tasklet_fn(unsigned long arg)
{
	struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg;

	spin_lock_irq(&host->lock);

	if (!host->data)
		goto out;

	if (host->data->flags & MMC_DATA_READ)
		dma_unmap_sg(host->chan_rx->device->dev,
			     host->sg_ptr, host->sg_len,
			     DMA_FROM_DEVICE);
	else
		dma_unmap_sg(host->chan_tx->device->dev,
			     host->sg_ptr, host->sg_len,
			     DMA_TO_DEVICE);

	tmio_mmc_do_data_irq(host);
out:
	spin_unlock_irq(&host->lock);
}

void tmio_mmc_request_dma(struct tmio_mmc_host *host, struct tmio_mmc_data *pdata)
{
	/* We can only either use DMA for both Tx and Rx or not use it at all */
	if (!host->dma || (!host->pdev->dev.of_node &&
		(!pdata->chan_priv_tx || !pdata->chan_priv_rx)))
		return;

	if (!host->chan_tx && !host->chan_rx) {
		struct resource *res = platform_get_resource(host->pdev,
							     IORESOURCE_MEM, 0);
		struct dma_slave_config cfg = {};
		dma_cap_mask_t mask;
		int ret;

		if (!res)
			return;

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

		host->chan_tx = dma_request_slave_channel_compat(mask,
					host->dma->filter, pdata->chan_priv_tx,
					&host->pdev->dev, "tx");
		dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__,
			host->chan_tx);

		if (!host->chan_tx)
			return;

		cfg.direction = DMA_MEM_TO_DEV;
		cfg.dst_addr = res->start + (CTL_SD_DATA_PORT << host->bus_shift);
		cfg.dst_addr_width = host->dma->dma_buswidth;
		if (!cfg.dst_addr_width)
			cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
		cfg.src_addr = 0;
		ret = dmaengine_slave_config(host->chan_tx, &cfg);
		if (ret < 0)
			goto ecfgtx;

		host->chan_rx = dma_request_slave_channel_compat(mask,
					host->dma->filter, pdata->chan_priv_rx,
					&host->pdev->dev, "rx");
		dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__,
			host->chan_rx);

		if (!host->chan_rx)
			goto ereqrx;

		cfg.direction = DMA_DEV_TO_MEM;
		cfg.src_addr = cfg.dst_addr + host->pdata->dma_rx_offset;
		cfg.src_addr_width = host->dma->dma_buswidth;
		if (!cfg.src_addr_width)
			cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
		cfg.dst_addr = 0;
		ret = dmaengine_slave_config(host->chan_rx, &cfg);
		if (ret < 0)
			goto ecfgrx;

		host->bounce_buf = (u8 *)__get_free_page(GFP_KERNEL | GFP_DMA);
		if (!host->bounce_buf)
			goto ebouncebuf;

		tasklet_init(&host->dma_complete, tmio_mmc_tasklet_fn, (unsigned long)host);
		tasklet_init(&host->dma_issue, tmio_mmc_issue_tasklet_fn, (unsigned long)host);
	}

	tmio_mmc_enable_dma(host, true);

	return;

ebouncebuf:
ecfgrx:
	dma_release_channel(host->chan_rx);
	host->chan_rx = NULL;
ereqrx:
ecfgtx:
	dma_release_channel(host->chan_tx);
	host->chan_tx = NULL;
}

void tmio_mmc_release_dma(struct tmio_mmc_host *host)
{
	if (host->chan_tx) {
		struct dma_chan *chan = host->chan_tx;
		host->chan_tx = NULL;
		dma_release_channel(chan);
	}
	if (host->chan_rx) {
		struct dma_chan *chan = host->chan_rx;
		host->chan_rx = NULL;
		dma_release_channel(chan);
	}
	if (host->bounce_buf) {
		free_pages((unsigned long)host->bounce_buf, 0);
		host->bounce_buf = NULL;
	}
}
Commit	Line	Data
b6147490 GL	1	/*
	2	* linux/drivers/mmc/tmio_mmc_dma.c
	3	*
	4	* Copyright (C) 2010-2011 Guennadi Liakhovetski
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	* DMA function for TMIO MMC implementations
	11	*/
	12
	13	#include <linux/device.h>
b7f080cf	14	#include <linux/dma-mapping.h>
b6147490 GL	15	#include <linux/dmaengine.h>
	16	#include <linux/mfd/tmio.h>
	17	#include <linux/mmc/host.h>
cba179ae	18	#include <linux/mmc/tmio.h>
b6147490 GL	19	#include <linux/pagemap.h>
	20	#include <linux/scatterlist.h>
	21
	22	#include "tmio_mmc.h"
	23
	24	#define TMIO_MMC_MIN_DMA_LEN 8
	25
162f43e3	26	void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
b6147490	27	{
162f43e3 GL	28	if (!host->chan_tx \|\| !host->chan_rx)
	29	return;
	30
5add2aca KM	31	if (host->dma->enable)
5add2aca KM	32	host->dma->enable(host, enable);
b6147490 GL	33	}
b6147490 GL	34
e3de2be7 GL	35	void tmio_mmc_abort_dma(struct tmio_mmc_host *host)
	36	{
	37	tmio_mmc_enable_dma(host, false);
	38
	39	if (host->chan_rx)
	40	dmaengine_terminate_all(host->chan_rx);
	41	if (host->chan_tx)
	42	dmaengine_terminate_all(host->chan_tx);
	43
	44	tmio_mmc_enable_dma(host, true);
	45	}
	46
b6147490 GL	47	static void tmio_mmc_start_dma_rx(struct tmio_mmc_host *host)
	48	{
	49	struct scatterlist sg = host->sg_ptr, sg_tmp;
	50	struct dma_async_tx_descriptor *desc = NULL;
	51	struct dma_chan *chan = host->chan_rx;
b6147490 GL	52	dma_cookie_t cookie;
	53	int ret, i;
	54	bool aligned = true, multiple = true;
e471df0b	55	unsigned int align = (1 << host->pdata->alignment_shift) - 1;
b6147490 GL	56
	57	for_each_sg(sg, sg_tmp, host->sg_len, i) {
	58	if (sg_tmp->offset & align)
	59	aligned = false;
	60	if (sg_tmp->length & align) {
	61	multiple = false;
	62	break;
	63	}
	64	}
	65
09cbfeaf	66	if ((!aligned && (host->sg_len > 1 \|\| sg->length > PAGE_SIZE \|\|
b6147490 GL	67	(align & PAGE_MASK))) \|\| !multiple) {
	68	ret = -EINVAL;
	69	goto pio;
	70	}
	71
	72	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
	73	host->force_pio = true;
	74	return;
	75	}
	76
	77	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_RXRDY);
	78
	79	/* The only sg element can be unaligned, use our bounce buffer then */
	80	if (!aligned) {
	81	sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
	82	host->sg_ptr = &host->bounce_sg;
	83	sg = host->sg_ptr;
	84	}
	85
	86	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_FROM_DEVICE);
	87	if (ret > 0)
16052827	88	desc = dmaengine_prep_slave_sg(chan, sg, ret,
05f5799c	89	DMA_DEV_TO_MEM, DMA_CTRL_ACK);
b6147490 GL	90
	91	if (desc) {
	92	cookie = dmaengine_submit(desc);
	93	if (cookie < 0) {
	94	desc = NULL;
	95	ret = cookie;
	96	}
	97	}
b6147490 GL	98	pio:
	99	if (!desc) {
	100	/* DMA failed, fall back to PIO */
f936f9b6	101	tmio_mmc_enable_dma(host, false);
b6147490 GL	102	if (ret >= 0)
	103	ret = -EIO;
	104	host->chan_rx = NULL;
	105	dma_release_channel(chan);
	106	/* Free the Tx channel too */
	107	chan = host->chan_tx;
	108	if (chan) {
	109	host->chan_tx = NULL;
	110	dma_release_channel(chan);
	111	}
	112	dev_warn(&host->pdev->dev,
	113	"DMA failed: %d, falling back to PIO\n", ret);
b6147490	114	}
b6147490 GL	115	}
	116
	117	static void tmio_mmc_start_dma_tx(struct tmio_mmc_host *host)
	118	{
	119	struct scatterlist sg = host->sg_ptr, sg_tmp;
	120	struct dma_async_tx_descriptor *desc = NULL;
	121	struct dma_chan *chan = host->chan_tx;
b6147490 GL	122	dma_cookie_t cookie;
	123	int ret, i;
	124	bool aligned = true, multiple = true;
e471df0b	125	unsigned int align = (1 << host->pdata->alignment_shift) - 1;
b6147490 GL	126
	127	for_each_sg(sg, sg_tmp, host->sg_len, i) {
	128	if (sg_tmp->offset & align)
	129	aligned = false;
	130	if (sg_tmp->length & align) {
	131	multiple = false;
	132	break;
	133	}
	134	}
	135
09cbfeaf	136	if ((!aligned && (host->sg_len > 1 \|\| sg->length > PAGE_SIZE \|\|
b6147490 GL	137	(align & PAGE_MASK))) \|\| !multiple) {
	138	ret = -EINVAL;
	139	goto pio;
	140	}
	141
	142	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
	143	host->force_pio = true;
	144	return;
	145	}
	146
	147	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_TXRQ);
	148
	149	/* The only sg element can be unaligned, use our bounce buffer then */
	150	if (!aligned) {
	151	unsigned long flags;
	152	void *sg_vaddr = tmio_mmc_kmap_atomic(sg, &flags);
	153	sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
	154	memcpy(host->bounce_buf, sg_vaddr, host->bounce_sg.length);
	155	tmio_mmc_kunmap_atomic(sg, &flags, sg_vaddr);
	156	host->sg_ptr = &host->bounce_sg;
	157	sg = host->sg_ptr;
	158	}
	159
	160	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_TO_DEVICE);
	161	if (ret > 0)
16052827	162	desc = dmaengine_prep_slave_sg(chan, sg, ret,
05f5799c	163	DMA_MEM_TO_DEV, DMA_CTRL_ACK);
b6147490 GL	164
	165	if (desc) {
	166	cookie = dmaengine_submit(desc);
	167	if (cookie < 0) {
	168	desc = NULL;
	169	ret = cookie;
	170	}
	171	}
b6147490 GL	172	pio:
	173	if (!desc) {
	174	/* DMA failed, fall back to PIO */
f936f9b6	175	tmio_mmc_enable_dma(host, false);
b6147490 GL	176	if (ret >= 0)
	177	ret = -EIO;
	178	host->chan_tx = NULL;
	179	dma_release_channel(chan);
	180	/* Free the Rx channel too */
	181	chan = host->chan_rx;
	182	if (chan) {
	183	host->chan_rx = NULL;
	184	dma_release_channel(chan);
	185	}
	186	dev_warn(&host->pdev->dev,
	187	"DMA failed: %d, falling back to PIO\n", ret);
b6147490	188	}
b6147490 GL	189	}
	190
	191	void tmio_mmc_start_dma(struct tmio_mmc_host *host,
	192	struct mmc_data *data)
	193	{
	194	if (data->flags & MMC_DATA_READ) {
	195	if (host->chan_rx)
	196	tmio_mmc_start_dma_rx(host);
	197	} else {
	198	if (host->chan_tx)
	199	tmio_mmc_start_dma_tx(host);
	200	}
	201	}
	202
	203	static void tmio_mmc_issue_tasklet_fn(unsigned long priv)
	204	{
	205	struct tmio_mmc_host host = (struct tmio_mmc_host )priv;
	206	struct dma_chan *chan = NULL;
	207
	208	spin_lock_irq(&host->lock);
	209
	210	if (host && host->data) {
	211	if (host->data->flags & MMC_DATA_READ)
	212	chan = host->chan_rx;
	213	else
	214	chan = host->chan_tx;
	215	}
	216
	217	spin_unlock_irq(&host->lock);
	218
	219	tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);
	220
	221	if (chan)
	222	dma_async_issue_pending(chan);
	223	}
	224
	225	static void tmio_mmc_tasklet_fn(unsigned long arg)
	226	{
	227	struct tmio_mmc_host host = (struct tmio_mmc_host )arg;
	228
	229	spin_lock_irq(&host->lock);
	230
	231	if (!host->data)
	232	goto out;
	233
	234	if (host->data->flags & MMC_DATA_READ)
	235	dma_unmap_sg(host->chan_rx->device->dev,
	236	host->sg_ptr, host->sg_len,
	237	DMA_FROM_DEVICE);
	238	else
	239	dma_unmap_sg(host->chan_tx->device->dev,
	240	host->sg_ptr, host->sg_len,
	241	DMA_TO_DEVICE);
	242
	243	tmio_mmc_do_data_irq(host);
	244	out:
	245	spin_unlock_irq(&host->lock);
	246	}
	247
b6147490 GL	248	void tmio_mmc_request_dma(struct tmio_mmc_host host, struct tmio_mmc_data pdata)
	249	{
	250	/* We can only either use DMA for both Tx and Rx or not use it at all */
7ecc09ba	251	if (!host->dma \|\| (!host->pdev->dev.of_node &&
f33c9d65	252	(!pdata->chan_priv_tx \|\| !pdata->chan_priv_rx)))
e6ee7182 GL	253	return;
	254
	255	if (!host->chan_tx && !host->chan_rx) {
eec95ee2 GL	256	struct resource *res = platform_get_resource(host->pdev,
	257	IORESOURCE_MEM, 0);
	258	struct dma_slave_config cfg = {};
b6147490	259	dma_cap_mask_t mask;
eec95ee2 GL	260	int ret;
	261
	262	if (!res)
	263	return;
b6147490 GL	264
	265	dma_cap_zero(mask);
	266	dma_cap_set(DMA_SLAVE, mask);
	267
87ae7bbe	268	host->chan_tx = dma_request_slave_channel_compat(mask,
f33c9d65	269	host->dma->filter, pdata->chan_priv_tx,
87ae7bbe	270	&host->pdev->dev, "tx");
b6147490 GL	271	dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__,
	272	host->chan_tx);
	273
	274	if (!host->chan_tx)
	275	return;
	276
eec95ee2	277	cfg.direction = DMA_MEM_TO_DEV;
7445bf9e	278	cfg.dst_addr = res->start + (CTL_SD_DATA_PORT << host->bus_shift);
361936ef KM	279	cfg.dst_addr_width = host->dma->dma_buswidth;
	280	if (!cfg.dst_addr_width)
	281	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
eec95ee2 GL	282	cfg.src_addr = 0;
	283	ret = dmaengine_slave_config(host->chan_tx, &cfg);
	284	if (ret < 0)
	285	goto ecfgtx;
	286
87ae7bbe	287	host->chan_rx = dma_request_slave_channel_compat(mask,
f33c9d65	288	host->dma->filter, pdata->chan_priv_rx,
87ae7bbe	289	&host->pdev->dev, "rx");
b6147490 GL	290	dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__,
	291	host->chan_rx);
	292
	293	if (!host->chan_rx)
	294	goto ereqrx;
	295
eec95ee2	296	cfg.direction = DMA_DEV_TO_MEM;
8b4c8f32	297	cfg.src_addr = cfg.dst_addr + host->pdata->dma_rx_offset;
361936ef KM	298	cfg.src_addr_width = host->dma->dma_buswidth;
	299	if (!cfg.src_addr_width)
	300	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
eec95ee2 GL	301	cfg.dst_addr = 0;
	302	ret = dmaengine_slave_config(host->chan_rx, &cfg);
	303	if (ret < 0)
	304	goto ecfgrx;
	305
b6147490 GL	306	host->bounce_buf = (u8 *)__get_free_page(GFP_KERNEL \| GFP_DMA);
	307	if (!host->bounce_buf)
	308	goto ebouncebuf;
	309
	310	tasklet_init(&host->dma_complete, tmio_mmc_tasklet_fn, (unsigned long)host);
	311	tasklet_init(&host->dma_issue, tmio_mmc_issue_tasklet_fn, (unsigned long)host);
e6ee7182	312	}
b6147490	313
e6ee7182 GL	314	tmio_mmc_enable_dma(host, true);
	315
	316	return;
b6147490	317
b6147490	318	ebouncebuf:
eec95ee2	319	ecfgrx:
e6ee7182 GL	320	dma_release_channel(host->chan_rx);
e6ee7182 GL	321	host->chan_rx = NULL;
b6147490	322	ereqrx:
eec95ee2	323	ecfgtx:
e6ee7182 GL	324	dma_release_channel(host->chan_tx);
e6ee7182 GL	325	host->chan_tx = NULL;
b6147490 GL	326	}
	327
	328	void tmio_mmc_release_dma(struct tmio_mmc_host *host)
	329	{
	330	if (host->chan_tx) {
	331	struct dma_chan *chan = host->chan_tx;
	332	host->chan_tx = NULL;
	333	dma_release_channel(chan);
	334	}
	335	if (host->chan_rx) {
	336	struct dma_chan *chan = host->chan_rx;
	337	host->chan_rx = NULL;
	338	dma_release_channel(chan);
	339	}
	340	if (host->bounce_buf) {
	341	free_pages((unsigned long)host->bounce_buf, 0);
	342	host->bounce_buf = NULL;
	343	}
	344	}