[mirror_ubuntu-zesty-kernel.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 defined(CONFIG_SUPERH) || defined(CONFIG_ARCH_SHMOBILE)
	/* Switch DMA mode on or off - SuperH specific? */
	sd_ctrl_write16(host, CTL_DMA_ENABLE, enable ? 2 : 0);
#endif
}

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;
	struct tmio_mmc_data *pdata = host->pdata;
	dma_cookie_t cookie;
	int ret, i;
	bool aligned = true, multiple = true;
	unsigned int align = (1 << pdata->dma->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_CACHE_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;
		}
	}
	dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n",
		__func__, host->sg_len, ret, cookie, host->mrq);

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);
	}

	dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d, sg[%d]\n", __func__,
		desc, cookie, host->sg_len);
}

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;
	struct tmio_mmc_data *pdata = host->pdata;
	dma_cookie_t cookie;
	int ret, i;
	bool aligned = true, multiple = true;
	unsigned int align = (1 << pdata->dma->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_CACHE_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;
		}
	}
	dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n",
		__func__, host->sg_len, ret, cookie, host->mrq);

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);
	}

	dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d\n", __func__,
		desc, cookie);
}

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 (!pdata->dma || (!host->pdev->dev.of_node &&
		(!pdata->dma->chan_priv_tx || !pdata->dma->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,
					pdata->dma->filter, pdata->dma->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;

		if (pdata->dma->chan_priv_tx)
			cfg.slave_id = pdata->dma->slave_id_tx;
		cfg.direction = DMA_MEM_TO_DEV;
		cfg.dst_addr = res->start + (CTL_SD_DATA_PORT << host->pdata->bus_shift);
		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,
					pdata->dma->filter, pdata->dma->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;

		if (pdata->dma->chan_priv_rx)
			cfg.slave_id = pdata->dma->slave_id_rx;
		cfg.direction = DMA_DEV_TO_MEM;
		cfg.src_addr = cfg.dst_addr + pdata->dma->dma_rx_offset;
		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
b6147490 GL	31	#if defined(CONFIG_SUPERH) \|\| defined(CONFIG_ARCH_SHMOBILE)
b6147490 GL	32	/* Switch DMA mode on or off - SuperH specific? */
332bdb50	33	sd_ctrl_write16(host, CTL_DMA_ENABLE, enable ? 2 : 0);
b6147490 GL	34	#endif
	35	}
	36
e3de2be7 GL	37	void tmio_mmc_abort_dma(struct tmio_mmc_host *host)
	38	{
	39	tmio_mmc_enable_dma(host, false);
	40
	41	if (host->chan_rx)
	42	dmaengine_terminate_all(host->chan_rx);
	43	if (host->chan_tx)
	44	dmaengine_terminate_all(host->chan_tx);
	45
	46	tmio_mmc_enable_dma(host, true);
	47	}
	48
b6147490 GL	49	static void tmio_mmc_start_dma_rx(struct tmio_mmc_host *host)
	50	{
	51	struct scatterlist sg = host->sg_ptr, sg_tmp;
	52	struct dma_async_tx_descriptor *desc = NULL;
	53	struct dma_chan *chan = host->chan_rx;
	54	struct tmio_mmc_data *pdata = host->pdata;
	55	dma_cookie_t cookie;
	56	int ret, i;
	57	bool aligned = true, multiple = true;
	58	unsigned int align = (1 << pdata->dma->alignment_shift) - 1;
	59
	60	for_each_sg(sg, sg_tmp, host->sg_len, i) {
	61	if (sg_tmp->offset & align)
	62	aligned = false;
	63	if (sg_tmp->length & align) {
	64	multiple = false;
	65	break;
	66	}
	67	}
	68
	69	if ((!aligned && (host->sg_len > 1 \|\| sg->length > PAGE_CACHE_SIZE \|\|
	70	(align & PAGE_MASK))) \|\| !multiple) {
	71	ret = -EINVAL;
	72	goto pio;
	73	}
	74
	75	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
	76	host->force_pio = true;
	77	return;
	78	}
	79
	80	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_RXRDY);
	81
	82	/* The only sg element can be unaligned, use our bounce buffer then */
	83	if (!aligned) {
	84	sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
	85	host->sg_ptr = &host->bounce_sg;
	86	sg = host->sg_ptr;
	87	}
	88
	89	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_FROM_DEVICE);
	90	if (ret > 0)
16052827	91	desc = dmaengine_prep_slave_sg(chan, sg, ret,
05f5799c	92	DMA_DEV_TO_MEM, DMA_CTRL_ACK);
b6147490 GL	93
	94	if (desc) {
	95	cookie = dmaengine_submit(desc);
	96	if (cookie < 0) {
	97	desc = NULL;
	98	ret = cookie;
	99	}
	100	}
	101	dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n",
	102	__func__, host->sg_len, ret, cookie, host->mrq);
	103
	104	pio:
	105	if (!desc) {
	106	/* DMA failed, fall back to PIO */
f936f9b6	107	tmio_mmc_enable_dma(host, false);
b6147490 GL	108	if (ret >= 0)
	109	ret = -EIO;
	110	host->chan_rx = NULL;
	111	dma_release_channel(chan);
	112	/* Free the Tx channel too */
	113	chan = host->chan_tx;
	114	if (chan) {
	115	host->chan_tx = NULL;
	116	dma_release_channel(chan);
	117	}
	118	dev_warn(&host->pdev->dev,
	119	"DMA failed: %d, falling back to PIO\n", ret);
b6147490 GL	120	}
	121
	122	dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d, sg[%d]\n", __func__,
	123	desc, cookie, host->sg_len);
	124	}
	125
	126	static void tmio_mmc_start_dma_tx(struct tmio_mmc_host *host)
	127	{
	128	struct scatterlist sg = host->sg_ptr, sg_tmp;
	129	struct dma_async_tx_descriptor *desc = NULL;
	130	struct dma_chan *chan = host->chan_tx;
	131	struct tmio_mmc_data *pdata = host->pdata;
	132	dma_cookie_t cookie;
	133	int ret, i;
	134	bool aligned = true, multiple = true;
	135	unsigned int align = (1 << pdata->dma->alignment_shift) - 1;
	136
	137	for_each_sg(sg, sg_tmp, host->sg_len, i) {
	138	if (sg_tmp->offset & align)
	139	aligned = false;
	140	if (sg_tmp->length & align) {
	141	multiple = false;
	142	break;
	143	}
	144	}
	145
	146	if ((!aligned && (host->sg_len > 1 \|\| sg->length > PAGE_CACHE_SIZE \|\|
	147	(align & PAGE_MASK))) \|\| !multiple) {
	148	ret = -EINVAL;
	149	goto pio;
	150	}
	151
	152	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
	153	host->force_pio = true;
	154	return;
	155	}
	156
	157	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_TXRQ);
	158
	159	/* The only sg element can be unaligned, use our bounce buffer then */
	160	if (!aligned) {
	161	unsigned long flags;
	162	void *sg_vaddr = tmio_mmc_kmap_atomic(sg, &flags);
	163	sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
	164	memcpy(host->bounce_buf, sg_vaddr, host->bounce_sg.length);
	165	tmio_mmc_kunmap_atomic(sg, &flags, sg_vaddr);
	166	host->sg_ptr = &host->bounce_sg;
	167	sg = host->sg_ptr;
	168	}
	169
	170	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_TO_DEVICE);
	171	if (ret > 0)
16052827	172	desc = dmaengine_prep_slave_sg(chan, sg, ret,
05f5799c	173	DMA_MEM_TO_DEV, DMA_CTRL_ACK);
b6147490 GL	174
	175	if (desc) {
	176	cookie = dmaengine_submit(desc);
	177	if (cookie < 0) {
	178	desc = NULL;
	179	ret = cookie;
	180	}
	181	}
	182	dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n",
	183	__func__, host->sg_len, ret, cookie, host->mrq);
	184
	185	pio:
	186	if (!desc) {
	187	/* DMA failed, fall back to PIO */
f936f9b6	188	tmio_mmc_enable_dma(host, false);
b6147490 GL	189	if (ret >= 0)
	190	ret = -EIO;
	191	host->chan_tx = NULL;
	192	dma_release_channel(chan);
	193	/* Free the Rx channel too */
	194	chan = host->chan_rx;
	195	if (chan) {
	196	host->chan_rx = NULL;
	197	dma_release_channel(chan);
	198	}
	199	dev_warn(&host->pdev->dev,
	200	"DMA failed: %d, falling back to PIO\n", ret);
b6147490 GL	201	}
	202
	203	dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d\n", __func__,
	204	desc, cookie);
	205	}
	206
	207	void tmio_mmc_start_dma(struct tmio_mmc_host *host,
	208	struct mmc_data *data)
	209	{
	210	if (data->flags & MMC_DATA_READ) {
	211	if (host->chan_rx)
	212	tmio_mmc_start_dma_rx(host);
	213	} else {
	214	if (host->chan_tx)
	215	tmio_mmc_start_dma_tx(host);
	216	}
	217	}
	218
	219	static void tmio_mmc_issue_tasklet_fn(unsigned long priv)
	220	{
	221	struct tmio_mmc_host host = (struct tmio_mmc_host )priv;
	222	struct dma_chan *chan = NULL;
	223
	224	spin_lock_irq(&host->lock);
	225
	226	if (host && host->data) {
	227	if (host->data->flags & MMC_DATA_READ)
	228	chan = host->chan_rx;
	229	else
	230	chan = host->chan_tx;
	231	}
	232
	233	spin_unlock_irq(&host->lock);
	234
	235	tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);
	236
	237	if (chan)
	238	dma_async_issue_pending(chan);
	239	}
	240
	241	static void tmio_mmc_tasklet_fn(unsigned long arg)
	242	{
	243	struct tmio_mmc_host host = (struct tmio_mmc_host )arg;
	244
	245	spin_lock_irq(&host->lock);
	246
	247	if (!host->data)
	248	goto out;
	249
	250	if (host->data->flags & MMC_DATA_READ)
	251	dma_unmap_sg(host->chan_rx->device->dev,
	252	host->sg_ptr, host->sg_len,
	253	DMA_FROM_DEVICE);
	254	else
	255	dma_unmap_sg(host->chan_tx->device->dev,
	256	host->sg_ptr, host->sg_len,
	257	DMA_TO_DEVICE);
	258
	259	tmio_mmc_do_data_irq(host);
	260	out:
	261	spin_unlock_irq(&host->lock);
	262	}
	263
b6147490 GL	264	void tmio_mmc_request_dma(struct tmio_mmc_host host, struct tmio_mmc_data pdata)
	265	{
	266	/* We can only either use DMA for both Tx and Rx or not use it at all */
87ae7bbe GL	267	if (!pdata->dma \|\| (!host->pdev->dev.of_node &&
87ae7bbe GL	268	(!pdata->dma->chan_priv_tx \|\| !pdata->dma->chan_priv_rx)))
e6ee7182 GL	269	return;
	270
	271	if (!host->chan_tx && !host->chan_rx) {
eec95ee2 GL	272	struct resource *res = platform_get_resource(host->pdev,
	273	IORESOURCE_MEM, 0);
	274	struct dma_slave_config cfg = {};
b6147490	275	dma_cap_mask_t mask;
eec95ee2 GL	276	int ret;
	277
	278	if (!res)
	279	return;
b6147490 GL	280
	281	dma_cap_zero(mask);
	282	dma_cap_set(DMA_SLAVE, mask);
	283
87ae7bbe GL	284	host->chan_tx = dma_request_slave_channel_compat(mask,
	285	pdata->dma->filter, pdata->dma->chan_priv_tx,
	286	&host->pdev->dev, "tx");
b6147490 GL	287	dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__,
	288	host->chan_tx);
	289
	290	if (!host->chan_tx)
	291	return;
	292
87ae7bbe GL	293	if (pdata->dma->chan_priv_tx)
87ae7bbe GL	294	cfg.slave_id = pdata->dma->slave_id_tx;
eec95ee2	295	cfg.direction = DMA_MEM_TO_DEV;
3b159a6e	296	cfg.dst_addr = res->start + (CTL_SD_DATA_PORT << host->pdata->bus_shift);
39ab1962	297	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
eec95ee2 GL	298	cfg.src_addr = 0;
	299	ret = dmaengine_slave_config(host->chan_tx, &cfg);
	300	if (ret < 0)
	301	goto ecfgtx;
	302
87ae7bbe GL	303	host->chan_rx = dma_request_slave_channel_compat(mask,
	304	pdata->dma->filter, pdata->dma->chan_priv_rx,
	305	&host->pdev->dev, "rx");
b6147490 GL	306	dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__,
	307	host->chan_rx);
	308
	309	if (!host->chan_rx)
	310	goto ereqrx;
	311
87ae7bbe GL	312	if (pdata->dma->chan_priv_rx)
87ae7bbe GL	313	cfg.slave_id = pdata->dma->slave_id_rx;
eec95ee2	314	cfg.direction = DMA_DEV_TO_MEM;
384b2cbd	315	cfg.src_addr = cfg.dst_addr + pdata->dma->dma_rx_offset;
39ab1962	316	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
eec95ee2 GL	317	cfg.dst_addr = 0;
	318	ret = dmaengine_slave_config(host->chan_rx, &cfg);
	319	if (ret < 0)
	320	goto ecfgrx;
	321
b6147490 GL	322	host->bounce_buf = (u8 *)__get_free_page(GFP_KERNEL \| GFP_DMA);
	323	if (!host->bounce_buf)
	324	goto ebouncebuf;
	325
	326	tasklet_init(&host->dma_complete, tmio_mmc_tasklet_fn, (unsigned long)host);
	327	tasklet_init(&host->dma_issue, tmio_mmc_issue_tasklet_fn, (unsigned long)host);
e6ee7182	328	}
b6147490	329
e6ee7182 GL	330	tmio_mmc_enable_dma(host, true);
	331
	332	return;
b6147490	333
b6147490	334	ebouncebuf:
eec95ee2	335	ecfgrx:
e6ee7182 GL	336	dma_release_channel(host->chan_rx);
e6ee7182 GL	337	host->chan_rx = NULL;
b6147490	338	ereqrx:
eec95ee2	339	ecfgtx:
e6ee7182 GL	340	dma_release_channel(host->chan_tx);
e6ee7182 GL	341	host->chan_tx = NULL;
b6147490 GL	342	}
	343
	344	void tmio_mmc_release_dma(struct tmio_mmc_host *host)
	345	{
	346	if (host->chan_tx) {
	347	struct dma_chan *chan = host->chan_tx;
	348	host->chan_tx = NULL;
	349	dma_release_channel(chan);
	350	}
	351	if (host->chan_rx) {
	352	struct dma_chan *chan = host->chan_rx;
	353	host->chan_rx = NULL;
	354	dma_release_channel(chan);
	355	}
	356	if (host->bounce_buf) {
	357	free_pages((unsigned long)host->bounce_buf, 0);
	358	host->bounce_buf = NULL;
	359	}
	360	}