[deliverable/linux.git] / sound / soc / soc-dmaengine-pcm.c

/*
 *  Copyright (C) 2012, Analog Devices Inc.
 *	Author: Lars-Peter Clausen <lars@metafoo.de>
 *
 *  Based on:
 *	imx-pcm-dma-mx2.c, Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
 *	mxs-pcm.c, Copyright (C) 2011 Freescale Semiconductor, Inc.
 *	ep93xx-pcm.c, Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
 *		      Copyright (C) 2006 Applied Data Systems
 *
 *  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.
 *
 *  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.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/dmaengine.h>
#include <linux/slab.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>

#include <sound/dmaengine_pcm.h>

struct dmaengine_pcm_runtime_data {
	struct dma_chan *dma_chan;
	dma_cookie_t cookie;

	unsigned int pos;

	void *data;
};

static inline struct dmaengine_pcm_runtime_data *substream_to_prtd(
	const struct snd_pcm_substream *substream)
{
	return substream->runtime->private_data;
}

/**
 * snd_dmaengine_pcm_set_data - Set dmaengine substream private data
 * @substream: PCM substream
 * @data: Data to set
 */
void snd_dmaengine_pcm_set_data(struct snd_pcm_substream *substream, void *data)
{
	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);

	prtd->data = data;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_data);

/**
 * snd_dmaengine_pcm_get_data - Get dmaeinge substream private data
 * @substream: PCM substream
 *
 * Returns the data previously set with snd_dmaengine_pcm_set_data
 */
void *snd_dmaengine_pcm_get_data(struct snd_pcm_substream *substream)
{
	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);

	return prtd->data;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_data);

struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream)
{
	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);

	return prtd->dma_chan;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan);

/**
 * snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config
 * @substream: PCM substream
 * @params: hw_params
 * @slave_config: DMA slave config
 *
 * This function can be used to initialize a dma_slave_config from a substream
 * and hw_params in a dmaengine based PCM driver implementation.
 */
int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
	const struct snd_pcm_hw_params *params,
	struct dma_slave_config *slave_config)
{
	enum dma_slave_buswidth buswidth;

	switch (params_format(params)) {
	case SNDRV_PCM_FORMAT_S8:
		buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
		break;
	case SNDRV_PCM_FORMAT_S16_LE:
		buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
		break;
	case SNDRV_PCM_FORMAT_S18_3LE:
	case SNDRV_PCM_FORMAT_S20_3LE:
	case SNDRV_PCM_FORMAT_S24_LE:
	case SNDRV_PCM_FORMAT_S32_LE:
		buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
		break;
	default:
		return -EINVAL;
	}

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		slave_config->direction = DMA_MEM_TO_DEV;
		slave_config->dst_addr_width = buswidth;
	} else {
		slave_config->direction = DMA_DEV_TO_MEM;
		slave_config->src_addr_width = buswidth;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);

static void dmaengine_pcm_dma_complete(void *arg)
{
	struct snd_pcm_substream *substream = arg;
	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);

	prtd->pos += snd_pcm_lib_period_bytes(substream);
	if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream))
		prtd->pos = 0;

	snd_pcm_period_elapsed(substream);
}

static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
{
	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	struct dma_chan *chan = prtd->dma_chan;
	struct dma_async_tx_descriptor *desc;
	enum dma_transfer_direction direction;
	unsigned long flags = DMA_CTRL_ACK;

	direction = snd_pcm_substream_to_dma_direction(substream);

	if (!substream->runtime->no_period_wakeup)
		flags |= DMA_PREP_INTERRUPT;

	prtd->pos = 0;
	desc = dmaengine_prep_dma_cyclic(chan,
		substream->runtime->dma_addr,
		snd_pcm_lib_buffer_bytes(substream),
		snd_pcm_lib_period_bytes(substream), direction, flags);

	if (!desc)
		return -ENOMEM;

	desc->callback = dmaengine_pcm_dma_complete;
	desc->callback_param = substream;
	prtd->cookie = dmaengine_submit(desc);

	return 0;
}

/**
 * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
 * @substream: PCM substream
 * @cmd: Trigger command
 *
 * Returns 0 on success, a negative error code otherwise.
 *
 * This function can be used as the PCM trigger callback for dmaengine based PCM
 * driver implementations.
 */
int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	int ret;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
		ret = dmaengine_pcm_prepare_and_submit(substream);
		if (ret)
			return ret;
		dma_async_issue_pending(prtd->dma_chan);
		break;
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
		dmaengine_resume(prtd->dma_chan);
		break;
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
		dmaengine_pause(prtd->dma_chan);
		break;
	case SNDRV_PCM_TRIGGER_STOP:
		dmaengine_terminate_all(prtd->dma_chan);
		break;
	default:
		return -EINVAL;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);

/**
 * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
 * @substream: PCM substream
 *
 * This function is deprecated and should not be used by new drivers, as its
 * results may be unreliable.
 */
snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
{
	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	return bytes_to_frames(substream->runtime, prtd->pos);
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);

/**
 * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
 * @substream: PCM substream
 *
 * This function can be used as the PCM pointer callback for dmaengine based PCM
 * driver implementations.
 */
snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
{
	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	struct dma_tx_state state;
	enum dma_status status;
	unsigned int buf_size;
	unsigned int pos = 0;

	status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
	if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
		buf_size = snd_pcm_lib_buffer_bytes(substream);
		if (state.residue > 0 && state.residue <= buf_size)
			pos = buf_size - state.residue;
	}

	return bytes_to_frames(substream->runtime, pos);
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);

static int dmaengine_pcm_request_channel(struct dmaengine_pcm_runtime_data *prtd,
	dma_filter_fn filter_fn, void *filter_data)
{
	dma_cap_mask_t mask;

	dma_cap_zero(mask);
	dma_cap_set(DMA_SLAVE, mask);
	dma_cap_set(DMA_CYCLIC, mask);
	prtd->dma_chan = dma_request_channel(mask, filter_fn, filter_data);

	if (!prtd->dma_chan)
		return -ENXIO;

	return 0;
}

/**
 * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
 * @substream: PCM substream
 * @filter_fn: Filter function used to request the DMA channel
 * @filter_data: Data passed to the DMA filter function
 *
 * Returns 0 on success, a negative error code otherwise.
 *
 * This function will request a DMA channel using the passed filter function and
 * data. The function should usually be called from the pcm open callback.
 *
 * Note that this function will use private_data field of the substream's
 * runtime. So it is not availabe to your pcm driver implementation. If you need
 * to keep additional data attached to a substream use
 * snd_dmaengine_pcm_{set,get}_data.
 */
int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
	dma_filter_fn filter_fn, void *filter_data)
{
	struct dmaengine_pcm_runtime_data *prtd;
	int ret;

	ret = snd_pcm_hw_constraint_integer(substream->runtime,
					    SNDRV_PCM_HW_PARAM_PERIODS);
	if (ret < 0)
		return ret;

	prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
	if (!prtd)
		return -ENOMEM;

	ret = dmaengine_pcm_request_channel(prtd, filter_fn, filter_data);
	if (ret < 0) {
		kfree(prtd);
		return ret;
	}

	substream->runtime->private_data = prtd;

	return 0;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);

/**
 * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
 * @substream: PCM substream
 */
int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
{
	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);

	dma_release_channel(prtd->dma_chan);
	kfree(prtd);

	return 0;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);

MODULE_LICENSE("GPL");
Commit	Line	Data
e7f73a16 LPC	1	/*
	2	* Copyright (C) 2012, Analog Devices Inc.
	3	* Author: Lars-Peter Clausen <lars@metafoo.de>
	4	*
	5	* Based on:
	6	* imx-pcm-dma-mx2.c, Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
	7	* mxs-pcm.c, Copyright (C) 2011 Freescale Semiconductor, Inc.
	8	* ep93xx-pcm.c, Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
	9	* Copyright (C) 2006 Applied Data Systems
	10	*
	11	* This program is free software; you can redistribute it and/or modify it
	12	* under the terms of the GNU General Public License as published by the
	13	* Free Software Foundation; either version 2 of the License, or (at your
	14	* option) any later version.
	15	*
	16	* You should have received a copy of the GNU General Public License along
	17	* with this program; if not, write to the Free Software Foundation, Inc.,
	18	* 675 Mass Ave, Cambridge, MA 02139, USA.
	19	*
	20	*/
	21	#include <linux/module.h>
	22	#include <linux/init.h>
	23	#include <linux/dmaengine.h>
	24	#include <linux/slab.h>
	25	#include <sound/pcm.h>
	26	#include <sound/pcm_params.h>
	27	#include <sound/soc.h>
	28
	29	#include <sound/dmaengine_pcm.h>
	30
	31	struct dmaengine_pcm_runtime_data {
	32	struct dma_chan *dma_chan;
3528f27a	33	dma_cookie_t cookie;
e7f73a16 LPC	34
	35	unsigned int pos;
	36
	37	void *data;
	38	};
	39
	40	static inline struct dmaengine_pcm_runtime_data *substream_to_prtd(
	41	const struct snd_pcm_substream *substream)
	42	{
	43	return substream->runtime->private_data;
	44	}
	45
	46	/**
	47	* snd_dmaengine_pcm_set_data - Set dmaengine substream private data
	48	* @substream: PCM substream
	49	* @data: Data to set
	50	*/
	51	void snd_dmaengine_pcm_set_data(struct snd_pcm_substream substream, void data)
	52	{
	53	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	54
	55	prtd->data = data;
	56	}
	57	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_data);
	58
	59	/**
	60	* snd_dmaengine_pcm_get_data - Get dmaeinge substream private data
	61	* @substream: PCM substream
	62	*
	63	* Returns the data previously set with snd_dmaengine_pcm_set_data
	64	*/
	65	void snd_dmaengine_pcm_get_data(struct snd_pcm_substream substream)
	66	{
	67	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	68
	69	return prtd->data;
	70	}
	71	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_data);
	72
	73	struct dma_chan snd_dmaengine_pcm_get_chan(struct snd_pcm_substream substream)
	74	{
	75	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	76
	77	return prtd->dma_chan;
	78	}
	79	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan);
	80
	81	/**
	82	* snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config
	83	* @substream: PCM substream
	84	* @params: hw_params
	85	* @slave_config: DMA slave config
	86	*
	87	* This function can be used to initialize a dma_slave_config from a substream
	88	* and hw_params in a dmaengine based PCM driver implementation.
	89	*/
	90	int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
	91	const struct snd_pcm_hw_params *params,
	92	struct dma_slave_config *slave_config)
	93	{
	94	enum dma_slave_buswidth buswidth;
	95
	96	switch (params_format(params)) {
	97	case SNDRV_PCM_FORMAT_S8:
98	buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
99	break;
100	case SNDRV_PCM_FORMAT_S16_LE:
101	buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
102	break;
103	case SNDRV_PCM_FORMAT_S18_3LE:
104	case SNDRV_PCM_FORMAT_S20_3LE:
105	case SNDRV_PCM_FORMAT_S24_LE:
106	case SNDRV_PCM_FORMAT_S32_LE:
107	buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
108	break;
109	default:
110	return -EINVAL;
111	}
112
113	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
114	slave_config->direction = DMA_MEM_TO_DEV;
115	slave_config->dst_addr_width = buswidth;
116	} else {
117	slave_config->direction = DMA_DEV_TO_MEM;
118	slave_config->src_addr_width = buswidth;
119	}
120
121	return 0;
122	}
123	EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
124
125	static void dmaengine_pcm_dma_complete(void *arg)
126	{
127	struct snd_pcm_substream *substream = arg;
128	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
129
130	prtd->pos += snd_pcm_lib_period_bytes(substream);
131	if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream))
132	prtd->pos = 0;
133
134	snd_pcm_period_elapsed(substream);
135	}
136
137	static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
138	{
139	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
140	struct dma_chan *chan = prtd->dma_chan;
141	struct dma_async_tx_descriptor *desc;
142	enum dma_transfer_direction direction;
e7736cde	143	unsigned long flags = DMA_CTRL_ACK;
e7f73a16 LPC	144
	145	direction = snd_pcm_substream_to_dma_direction(substream);
	146
e7736cde PU	147	if (!substream->runtime->no_period_wakeup)
	148	flags \|= DMA_PREP_INTERRUPT;
	149
7a08cf70	150	prtd->pos = 0;
41ba6b71	151	desc = dmaengine_prep_dma_cyclic(chan,
e7f73a16 LPC	152	substream->runtime->dma_addr,
e7f73a16 LPC	153	snd_pcm_lib_buffer_bytes(substream),
e7736cde	154	snd_pcm_lib_period_bytes(substream), direction, flags);
e7f73a16 LPC	155
	156	if (!desc)
	157	return -ENOMEM;
	158
	159	desc->callback = dmaengine_pcm_dma_complete;
	160	desc->callback_param = substream;
3528f27a	161	prtd->cookie = dmaengine_submit(desc);
e7f73a16 LPC	162
	163	return 0;
	164	}
	165
	166	/**
	167	* snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
	168	* @substream: PCM substream
	169	* @cmd: Trigger command
	170	*
	171	* Returns 0 on success, a negative error code otherwise.
	172	*
	173	* This function can be used as the PCM trigger callback for dmaengine based PCM
	174	* driver implementations.
	175	*/
	176	int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
	177	{
	178	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	179	int ret;
	180
	181	switch (cmd) {
	182	case SNDRV_PCM_TRIGGER_START:
	183	ret = dmaengine_pcm_prepare_and_submit(substream);
	184	if (ret)
	185	return ret;
	186	dma_async_issue_pending(prtd->dma_chan);
	187	break;
	188	case SNDRV_PCM_TRIGGER_RESUME:
	189	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
	190	dmaengine_resume(prtd->dma_chan);
	191	break;
	192	case SNDRV_PCM_TRIGGER_SUSPEND:
	193	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
	194	dmaengine_pause(prtd->dma_chan);
	195	break;
	196	case SNDRV_PCM_TRIGGER_STOP:
	197	dmaengine_terminate_all(prtd->dma_chan);
	198	break;
	199	default:
	200	return -EINVAL;
	201	}
	202
	203	return 0;
	204	}
	205	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
	206
	207	/**
9883ab22	208	* snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
e7f73a16 LPC	209	* @substream: PCM substream
e7f73a16 LPC	210	*
9883ab22 LPC	211	* This function is deprecated and should not be used by new drivers, as its
9883ab22 LPC	212	* results may be unreliable.
e7f73a16	213	*/
9883ab22	214	snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
e7f73a16 LPC	215	{
	216	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	217	return bytes_to_frames(substream->runtime, prtd->pos);
	218	}
9883ab22	219	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
e7f73a16	220
3528f27a LPC	221	/**
	222	* snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
	223	* @substream: PCM substream
	224	*
	225	* This function can be used as the PCM pointer callback for dmaengine based PCM
	226	* driver implementations.
	227	*/
	228	snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
	229	{
	230	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	231	struct dma_tx_state state;
	232	enum dma_status status;
	233	unsigned int buf_size;
	234	unsigned int pos = 0;
	235
	236	status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
	237	if (status == DMA_IN_PROGRESS \|\| status == DMA_PAUSED) {
	238	buf_size = snd_pcm_lib_buffer_bytes(substream);
	239	if (state.residue > 0 && state.residue <= buf_size)
	240	pos = buf_size - state.residue;
	241	}
	242
	243	return bytes_to_frames(substream->runtime, pos);
	244	}
	245	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
	246
e7f73a16 LPC	247	static int dmaengine_pcm_request_channel(struct dmaengine_pcm_runtime_data *prtd,
	248	dma_filter_fn filter_fn, void *filter_data)
	249	{
	250	dma_cap_mask_t mask;
	251
	252	dma_cap_zero(mask);
	253	dma_cap_set(DMA_SLAVE, mask);
	254	dma_cap_set(DMA_CYCLIC, mask);
	255	prtd->dma_chan = dma_request_channel(mask, filter_fn, filter_data);
	256
	257	if (!prtd->dma_chan)
	258	return -ENXIO;
	259
	260	return 0;
	261	}
	262
	263	/**
	264	* snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
	265	* @substream: PCM substream
	266	* @filter_fn: Filter function used to request the DMA channel
	267	* @filter_data: Data passed to the DMA filter function
	268	*
	269	* Returns 0 on success, a negative error code otherwise.
	270	*
	271	* This function will request a DMA channel using the passed filter function and
	272	* data. The function should usually be called from the pcm open callback.
	273	*
	274	* Note that this function will use private_data field of the substream's
	275	* runtime. So it is not availabe to your pcm driver implementation. If you need
	276	* to keep additional data attached to a substream use
1573ee81	277	* snd_dmaengine_pcm_{set,get}_data.
e7f73a16 LPC	278	*/
	279	int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
	280	dma_filter_fn filter_fn, void *filter_data)
	281	{
	282	struct dmaengine_pcm_runtime_data *prtd;
	283	int ret;
	284
	285	ret = snd_pcm_hw_constraint_integer(substream->runtime,
	286	SNDRV_PCM_HW_PARAM_PERIODS);
	287	if (ret < 0)
	288	return ret;
	289
	290	prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
	291	if (!prtd)
	292	return -ENOMEM;
	293
	294	ret = dmaengine_pcm_request_channel(prtd, filter_fn, filter_data);
	295	if (ret < 0) {
	296	kfree(prtd);
	297	return ret;
	298	}
	299
	300	substream->runtime->private_data = prtd;
	301
	302	return 0;
	303	}
	304	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
	305
	306	/**
	307	* snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
	308	* @substream: PCM substream
	309	*/
	310	int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
	311	{
	312	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	313
	314	dma_release_channel(prtd->dma_chan);
	315	kfree(prtd);
	316
	317	return 0;
	318	}
	319	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
cba69b4d LW	320
cba69b4d LW	321	MODULE_LICENSE("GPL");