[mirror_ubuntu-hirsute-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 (host->pdata->flags & TMIO_MMC_HAVE_CTL_DMA_REG)
		sd_ctrl_write16(host, CTL_DMA_ENABLE, enable ? 2 : 0);
}

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
e85dd04e KM	31	if (host->pdata->flags & TMIO_MMC_HAVE_CTL_DMA_REG)
e85dd04e KM	32	sd_ctrl_write16(host, CTL_DMA_ENABLE, enable ? 2 : 0);
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;
	52	struct tmio_mmc_data *pdata = host->pdata;
	53	dma_cookie_t cookie;
	54	int ret, i;
	55	bool aligned = true, multiple = true;
	56	unsigned int align = (1 << pdata->dma->alignment_shift) - 1;
	57
	58	for_each_sg(sg, sg_tmp, host->sg_len, i) {
	59	if (sg_tmp->offset & align)
	60	aligned = false;
	61	if (sg_tmp->length & align) {
	62	multiple = false;
	63	break;
	64	}
	65	}
	66
	67	if ((!aligned && (host->sg_len > 1 \|\| sg->length > PAGE_CACHE_SIZE \|\|
	68	(align & PAGE_MASK))) \|\| !multiple) {
	69	ret = -EINVAL;
	70	goto pio;
	71	}
	72
	73	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
	74	host->force_pio = true;
	75	return;
	76	}
	77
	78	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_RXRDY);
	79
	80	/* The only sg element can be unaligned, use our bounce buffer then */
	81	if (!aligned) {
	82	sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
	83	host->sg_ptr = &host->bounce_sg;
	84	sg = host->sg_ptr;
	85	}
	86
	87	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_FROM_DEVICE);
	88	if (ret > 0)
16052827	89	desc = dmaengine_prep_slave_sg(chan, sg, ret,
05f5799c	90	DMA_DEV_TO_MEM, DMA_CTRL_ACK);
b6147490 GL	91
	92	if (desc) {
	93	cookie = dmaengine_submit(desc);
	94	if (cookie < 0) {
	95	desc = NULL;
	96	ret = cookie;
	97	}
	98	}
	99	dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n",
	100	__func__, host->sg_len, ret, cookie, host->mrq);
	101
	102	pio:
	103	if (!desc) {
	104	/* DMA failed, fall back to PIO */
f936f9b6	105	tmio_mmc_enable_dma(host, false);
b6147490 GL	106	if (ret >= 0)
	107	ret = -EIO;
	108	host->chan_rx = NULL;
	109	dma_release_channel(chan);
	110	/* Free the Tx channel too */
	111	chan = host->chan_tx;
	112	if (chan) {
	113	host->chan_tx = NULL;
	114	dma_release_channel(chan);
	115	}
	116	dev_warn(&host->pdev->dev,
	117	"DMA failed: %d, falling back to PIO\n", ret);
b6147490 GL	118	}
	119
	120	dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d, sg[%d]\n", __func__,
	121	desc, cookie, host->sg_len);
	122	}
	123
	124	static void tmio_mmc_start_dma_tx(struct tmio_mmc_host *host)
	125	{
	126	struct scatterlist sg = host->sg_ptr, sg_tmp;
	127	struct dma_async_tx_descriptor *desc = NULL;
	128	struct dma_chan *chan = host->chan_tx;
	129	struct tmio_mmc_data *pdata = host->pdata;
	130	dma_cookie_t cookie;
	131	int ret, i;
	132	bool aligned = true, multiple = true;
	133	unsigned int align = (1 << pdata->dma->alignment_shift) - 1;
	134
	135	for_each_sg(sg, sg_tmp, host->sg_len, i) {
	136	if (sg_tmp->offset & align)
	137	aligned = false;
	138	if (sg_tmp->length & align) {
	139	multiple = false;
	140	break;
	141	}
	142	}
	143
	144	if ((!aligned && (host->sg_len > 1 \|\| sg->length > PAGE_CACHE_SIZE \|\|
	145	(align & PAGE_MASK))) \|\| !multiple) {
	146	ret = -EINVAL;
	147	goto pio;
	148	}
	149
	150	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
	151	host->force_pio = true;
	152	return;
	153	}
	154
	155	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_TXRQ);
	156
	157	/* The only sg element can be unaligned, use our bounce buffer then */
	158	if (!aligned) {
	159	unsigned long flags;
	160	void *sg_vaddr = tmio_mmc_kmap_atomic(sg, &flags);
	161	sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
	162	memcpy(host->bounce_buf, sg_vaddr, host->bounce_sg.length);
	163	tmio_mmc_kunmap_atomic(sg, &flags, sg_vaddr);
	164	host->sg_ptr = &host->bounce_sg;
	165	sg = host->sg_ptr;
	166	}
	167
	168	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_TO_DEVICE);
	169	if (ret > 0)
16052827	170	desc = dmaengine_prep_slave_sg(chan, sg, ret,
05f5799c	171	DMA_MEM_TO_DEV, DMA_CTRL_ACK);
b6147490 GL	172
	173	if (desc) {
	174	cookie = dmaengine_submit(desc);
	175	if (cookie < 0) {
	176	desc = NULL;
	177	ret = cookie;
	178	}
	179	}
	180	dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n",
	181	__func__, host->sg_len, ret, cookie, host->mrq);
	182
	183	pio:
	184	if (!desc) {
	185	/* DMA failed, fall back to PIO */
f936f9b6	186	tmio_mmc_enable_dma(host, false);
b6147490 GL	187	if (ret >= 0)
	188	ret = -EIO;
	189	host->chan_tx = NULL;
	190	dma_release_channel(chan);
	191	/* Free the Rx channel too */
	192	chan = host->chan_rx;
	193	if (chan) {
	194	host->chan_rx = NULL;
	195	dma_release_channel(chan);
	196	}
	197	dev_warn(&host->pdev->dev,
	198	"DMA failed: %d, falling back to PIO\n", ret);
b6147490 GL	199	}
	200
	201	dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d\n", __func__,
	202	desc, cookie);
	203	}
	204
	205	void tmio_mmc_start_dma(struct tmio_mmc_host *host,
	206	struct mmc_data *data)
	207	{
	208	if (data->flags & MMC_DATA_READ) {
	209	if (host->chan_rx)
	210	tmio_mmc_start_dma_rx(host);
	211	} else {
	212	if (host->chan_tx)
	213	tmio_mmc_start_dma_tx(host);
	214	}
	215	}
	216
	217	static void tmio_mmc_issue_tasklet_fn(unsigned long priv)
	218	{
	219	struct tmio_mmc_host host = (struct tmio_mmc_host )priv;
	220	struct dma_chan *chan = NULL;
	221
	222	spin_lock_irq(&host->lock);
	223
	224	if (host && host->data) {
	225	if (host->data->flags & MMC_DATA_READ)
	226	chan = host->chan_rx;
	227	else
	228	chan = host->chan_tx;
	229	}
	230
	231	spin_unlock_irq(&host->lock);
	232
	233	tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);
	234
	235	if (chan)
	236	dma_async_issue_pending(chan);
	237	}
	238
	239	static void tmio_mmc_tasklet_fn(unsigned long arg)
	240	{
	241	struct tmio_mmc_host host = (struct tmio_mmc_host )arg;
	242
	243	spin_lock_irq(&host->lock);
	244
	245	if (!host->data)
	246	goto out;
	247
	248	if (host->data->flags & MMC_DATA_READ)
	249	dma_unmap_sg(host->chan_rx->device->dev,
	250	host->sg_ptr, host->sg_len,
	251	DMA_FROM_DEVICE);
	252	else
	253	dma_unmap_sg(host->chan_tx->device->dev,
	254	host->sg_ptr, host->sg_len,
	255	DMA_TO_DEVICE);
	256
	257	tmio_mmc_do_data_irq(host);
	258	out:
	259	spin_unlock_irq(&host->lock);
	260	}
	261
b6147490 GL	262	void tmio_mmc_request_dma(struct tmio_mmc_host host, struct tmio_mmc_data pdata)
	263	{
	264	/* We can only either use DMA for both Tx and Rx or not use it at all */
87ae7bbe GL	265	if (!pdata->dma \|\| (!host->pdev->dev.of_node &&
87ae7bbe GL	266	(!pdata->dma->chan_priv_tx \|\| !pdata->dma->chan_priv_rx)))
e6ee7182 GL	267	return;
	268
	269	if (!host->chan_tx && !host->chan_rx) {
eec95ee2 GL	270	struct resource *res = platform_get_resource(host->pdev,
	271	IORESOURCE_MEM, 0);
	272	struct dma_slave_config cfg = {};
b6147490	273	dma_cap_mask_t mask;
eec95ee2 GL	274	int ret;
	275
	276	if (!res)
	277	return;
b6147490 GL	278
	279	dma_cap_zero(mask);
	280	dma_cap_set(DMA_SLAVE, mask);
	281
87ae7bbe GL	282	host->chan_tx = dma_request_slave_channel_compat(mask,
	283	pdata->dma->filter, pdata->dma->chan_priv_tx,
	284	&host->pdev->dev, "tx");
b6147490 GL	285	dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__,
	286	host->chan_tx);
	287
	288	if (!host->chan_tx)
	289	return;
	290
87ae7bbe GL	291	if (pdata->dma->chan_priv_tx)
87ae7bbe GL	292	cfg.slave_id = pdata->dma->slave_id_tx;
eec95ee2	293	cfg.direction = DMA_MEM_TO_DEV;
3b159a6e	294	cfg.dst_addr = res->start + (CTL_SD_DATA_PORT << host->pdata->bus_shift);
39ab1962	295	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
eec95ee2 GL	296	cfg.src_addr = 0;
	297	ret = dmaengine_slave_config(host->chan_tx, &cfg);
	298	if (ret < 0)
	299	goto ecfgtx;
	300
87ae7bbe GL	301	host->chan_rx = dma_request_slave_channel_compat(mask,
	302	pdata->dma->filter, pdata->dma->chan_priv_rx,
	303	&host->pdev->dev, "rx");
b6147490 GL	304	dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__,
	305	host->chan_rx);
	306
	307	if (!host->chan_rx)
	308	goto ereqrx;
	309
87ae7bbe GL	310	if (pdata->dma->chan_priv_rx)
87ae7bbe GL	311	cfg.slave_id = pdata->dma->slave_id_rx;
eec95ee2	312	cfg.direction = DMA_DEV_TO_MEM;
384b2cbd	313	cfg.src_addr = cfg.dst_addr + pdata->dma->dma_rx_offset;
39ab1962	314	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
eec95ee2 GL	315	cfg.dst_addr = 0;
	316	ret = dmaengine_slave_config(host->chan_rx, &cfg);
	317	if (ret < 0)
	318	goto ecfgrx;
	319
b6147490 GL	320	host->bounce_buf = (u8 *)__get_free_page(GFP_KERNEL \| GFP_DMA);
	321	if (!host->bounce_buf)
	322	goto ebouncebuf;
	323
	324	tasklet_init(&host->dma_complete, tmio_mmc_tasklet_fn, (unsigned long)host);
	325	tasklet_init(&host->dma_issue, tmio_mmc_issue_tasklet_fn, (unsigned long)host);
e6ee7182	326	}
b6147490	327
e6ee7182 GL	328	tmio_mmc_enable_dma(host, true);
	329
	330	return;
b6147490	331
b6147490	332	ebouncebuf:
eec95ee2	333	ecfgrx:
e6ee7182 GL	334	dma_release_channel(host->chan_rx);
e6ee7182 GL	335	host->chan_rx = NULL;
b6147490	336	ereqrx:
eec95ee2	337	ecfgtx:
e6ee7182 GL	338	dma_release_channel(host->chan_tx);
e6ee7182 GL	339	host->chan_tx = NULL;
b6147490 GL	340	}
	341
	342	void tmio_mmc_release_dma(struct tmio_mmc_host *host)
	343	{
	344	if (host->chan_tx) {
	345	struct dma_chan *chan = host->chan_tx;
	346	host->chan_tx = NULL;
	347	dma_release_channel(chan);
	348	}
	349	if (host->chan_rx) {
	350	struct dma_chan *chan = host->chan_rx;
	351	host->chan_rx = NULL;
	352	dma_release_channel(chan);
	353	}
	354	if (host->bounce_buf) {
	355	free_pages((unsigned long)host->bounce_buf, 0);
	356	host->bounce_buf = NULL;
	357	}
	358	}