[deliverable/linux.git] / sound / core / pcm_dmaengine.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;
};

static inline struct dmaengine_pcm_runtime_data *substream_to_prtd(
	const struct snd_pcm_substream *substream)
{
	return substream->runtime->private_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;
	int bits;

	bits = snd_pcm_format_physical_width(params_format(params));
	if (bits < 8 || bits > 64)
		return -EINVAL;
	else if (bits == 8)
		buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
	else if (bits == 16)
		buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
	else if (bits <= 32)
		buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
	else
		buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES;

	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;
	}

	slave_config->device_fc = false;

	return 0;
}
EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);

/**
 * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config
 *  using DAI DMA data.
 * @substream: PCM substream
 * @dma_data: DAI DMA data
 * @slave_config: DMA slave configuration
 *
 * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and
 * slave_id fields of the DMA slave config from the same fields of the DAI DMA
 * data struct. The src and dst fields will be initialized depending on the
 * direction of the substream. If the substream is a playback stream the dst
 * fields will be initialized, if it is a capture stream the src fields will be
 * initialized. The {dst,src}_addr_width field will only be initialized if the
 * addr_width field of the DAI DMA data struct is not equal to
 * DMA_SLAVE_BUSWIDTH_UNDEFINED.
 */
void snd_dmaengine_pcm_set_config_from_dai_data(
	const struct snd_pcm_substream *substream,
	const struct snd_dmaengine_dai_dma_data *dma_data,
	struct dma_slave_config *slave_config)
{
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		slave_config->dst_addr = dma_data->addr;
		slave_config->dst_maxburst = dma_data->maxburst;
		if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
			slave_config->dst_addr_width = dma_data->addr_width;
	} else {
		slave_config->src_addr = dma_data->addr;
		slave_config->src_maxburst = dma_data->maxburst;
		if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
			slave_config->src_addr_width = dma_data->addr_width;
	}

	slave_config->slave_id = dma_data->slave_id;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data);

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);
	struct snd_pcm_runtime *runtime = substream->runtime;
	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:
		if (runtime->info & SNDRV_PCM_INFO_PAUSE)
			dmaengine_pause(prtd->dma_chan);
		else
			dmaengine_terminate_all(prtd->dma_chan);
		break;
	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);

/**
 * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM
 * @filter_fn: Filter function used to request the DMA channel
 * @filter_data: Data passed to the DMA filter function
 *
 * Returns NULL or the requested DMA channel.
 *
 * This function request a DMA channel for usage with dmaengine PCM.
 */
struct dma_chan *snd_dmaengine_pcm_request_channel(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);

	return dma_request_channel(mask, filter_fn, filter_data);
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel);

/**
 * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
 * @substream: PCM substream
 * @chan: DMA channel to use for data transfers
 *
 * Returns 0 on success, a negative error code otherwise.
 *
 * 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.
 */
int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
	struct dma_chan *chan)
{
	struct dmaengine_pcm_runtime_data *prtd;
	int ret;

	if (!chan)
		return -ENXIO;

	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;

	prtd->dma_chan = chan;

	substream->runtime->private_data = prtd;

	return 0;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);

/**
 * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel
 * @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.
 */
int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
	dma_filter_fn filter_fn, void *filter_data)
{
	return snd_dmaengine_pcm_open(substream,
		    snd_dmaengine_pcm_request_channel(filter_fn, filter_data));
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);

/**
 * 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);

	kfree(prtd);

	return 0;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);

/**
 * snd_dmaengine_pcm_release_chan_close - Close a dmaengine based PCM substream and release channel
 * @substream: PCM substream
 *
 * Releases the DMA channel associated with the PCM substream.
 */
int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
{
	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);

	dma_release_channel(prtd->dma_chan);

	return snd_dmaengine_pcm_close(substream);
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan);

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
e7f73a16 LPC	35	unsigned int pos;
e7f73a16 LPC	36	};
	37
	38	static inline struct dmaengine_pcm_runtime_data *substream_to_prtd(
	39	const struct snd_pcm_substream *substream)
	40	{
	41	return substream->runtime->private_data;
	42	}
	43
e7f73a16 LPC	44	struct dma_chan snd_dmaengine_pcm_get_chan(struct snd_pcm_substream substream)
	45	{
	46	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	47
	48	return prtd->dma_chan;
	49	}
	50	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan);
	51
	52	/**
	53	* snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config
	54	* @substream: PCM substream
	55	* @params: hw_params
	56	* @slave_config: DMA slave config
	57	*
	58	* This function can be used to initialize a dma_slave_config from a substream
	59	* and hw_params in a dmaengine based PCM driver implementation.
	60	*/
	61	int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
	62	const struct snd_pcm_hw_params *params,
	63	struct dma_slave_config *slave_config)
	64	{
	65	enum dma_slave_buswidth buswidth;
a655f75c	66	int bits;
e7f73a16	67
a655f75c TI	68	bits = snd_pcm_format_physical_width(params_format(params));
	69	if (bits < 8 \|\| bits > 64)
	70	return -EINVAL;
	71	else if (bits == 8)
e7f73a16	72	buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
a655f75c	73	else if (bits == 16)
e7f73a16	74	buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
a655f75c	75	else if (bits <= 32)
e7f73a16	76	buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
a655f75c TI	77	else
a655f75c TI	78	buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES;
e7f73a16 LPC	79
	80	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
	81	slave_config->direction = DMA_MEM_TO_DEV;
	82	slave_config->dst_addr_width = buswidth;
	83	} else {
	84	slave_config->direction = DMA_DEV_TO_MEM;
	85	slave_config->src_addr_width = buswidth;
	86	}
	87
5fa70f71 LPC	88	slave_config->device_fc = false;
5fa70f71 LPC	89
e7f73a16 LPC	90	return 0;
	91	}
	92	EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
	93
85c9f9c5 LPC	94	/**
	95	* snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config
	96	* using DAI DMA data.
	97	* @substream: PCM substream
	98	* @dma_data: DAI DMA data
	99	* @slave_config: DMA slave configuration
	100	*
	101	* Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and
	102	* slave_id fields of the DMA slave config from the same fields of the DAI DMA
	103	* data struct. The src and dst fields will be initialized depending on the
	104	* direction of the substream. If the substream is a playback stream the dst
	105	* fields will be initialized, if it is a capture stream the src fields will be
	106	* initialized. The {dst,src}_addr_width field will only be initialized if the
	107	* addr_width field of the DAI DMA data struct is not equal to
	108	* DMA_SLAVE_BUSWIDTH_UNDEFINED.
	109	*/
	110	void snd_dmaengine_pcm_set_config_from_dai_data(
	111	const struct snd_pcm_substream *substream,
	112	const struct snd_dmaengine_dai_dma_data *dma_data,
	113	struct dma_slave_config *slave_config)
	114	{
	115	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
	116	slave_config->dst_addr = dma_data->addr;
	117	slave_config->dst_maxburst = dma_data->maxburst;
	118	if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
	119	slave_config->dst_addr_width = dma_data->addr_width;
	120	} else {
	121	slave_config->src_addr = dma_data->addr;
	122	slave_config->src_maxburst = dma_data->maxburst;
	123	if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
	124	slave_config->src_addr_width = dma_data->addr_width;
	125	}
	126
	127	slave_config->slave_id = dma_data->slave_id;
	128	}
	129	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data);
	130
e7f73a16 LPC	131	static void dmaengine_pcm_dma_complete(void *arg)
	132	{
	133	struct snd_pcm_substream *substream = arg;
	134	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	135
	136	prtd->pos += snd_pcm_lib_period_bytes(substream);
	137	if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream))
	138	prtd->pos = 0;
	139
	140	snd_pcm_period_elapsed(substream);
	141	}
	142
	143	static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
	144	{
	145	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	146	struct dma_chan *chan = prtd->dma_chan;
	147	struct dma_async_tx_descriptor *desc;
	148	enum dma_transfer_direction direction;
e7736cde	149	unsigned long flags = DMA_CTRL_ACK;
e7f73a16 LPC	150
	151	direction = snd_pcm_substream_to_dma_direction(substream);
	152
e7736cde PU	153	if (!substream->runtime->no_period_wakeup)
	154	flags \|= DMA_PREP_INTERRUPT;
	155
7a08cf70	156	prtd->pos = 0;
41ba6b71	157	desc = dmaengine_prep_dma_cyclic(chan,
e7f73a16 LPC	158	substream->runtime->dma_addr,
e7f73a16 LPC	159	snd_pcm_lib_buffer_bytes(substream),
e7736cde	160	snd_pcm_lib_period_bytes(substream), direction, flags);
e7f73a16 LPC	161
	162	if (!desc)
	163	return -ENOMEM;
	164
	165	desc->callback = dmaengine_pcm_dma_complete;
	166	desc->callback_param = substream;
3528f27a	167	prtd->cookie = dmaengine_submit(desc);
e7f73a16 LPC	168
	169	return 0;
	170	}
	171
	172	/**
	173	* snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
	174	* @substream: PCM substream
	175	* @cmd: Trigger command
	176	*
	177	* Returns 0 on success, a negative error code otherwise.
	178	*
	179	* This function can be used as the PCM trigger callback for dmaengine based PCM
	180	* driver implementations.
	181	*/
	182	int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
	183	{
	184	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
02fb05a5	185	struct snd_pcm_runtime *runtime = substream->runtime;
e7f73a16 LPC	186	int ret;
	187
	188	switch (cmd) {
	189	case SNDRV_PCM_TRIGGER_START:
	190	ret = dmaengine_pcm_prepare_and_submit(substream);
	191	if (ret)
	192	return ret;
	193	dma_async_issue_pending(prtd->dma_chan);
	194	break;
	195	case SNDRV_PCM_TRIGGER_RESUME:
	196	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
	197	dmaengine_resume(prtd->dma_chan);
	198	break;
	199	case SNDRV_PCM_TRIGGER_SUSPEND:
02fb05a5 TB	200	if (runtime->info & SNDRV_PCM_INFO_PAUSE)
	201	dmaengine_pause(prtd->dma_chan);
	202	else
	203	dmaengine_terminate_all(prtd->dma_chan);
	204	break;
e7f73a16 LPC	205	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
	206	dmaengine_pause(prtd->dma_chan);
	207	break;
	208	case SNDRV_PCM_TRIGGER_STOP:
	209	dmaengine_terminate_all(prtd->dma_chan);
	210	break;
	211	default:
	212	return -EINVAL;
	213	}
	214
	215	return 0;
	216	}
	217	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
	218
	219	/**
9883ab22	220	* snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
e7f73a16 LPC	221	* @substream: PCM substream
e7f73a16 LPC	222	*
9883ab22 LPC	223	* This function is deprecated and should not be used by new drivers, as its
9883ab22 LPC	224	* results may be unreliable.
e7f73a16	225	*/
9883ab22	226	snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
e7f73a16 LPC	227	{
	228	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	229	return bytes_to_frames(substream->runtime, prtd->pos);
	230	}
9883ab22	231	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
e7f73a16	232
3528f27a LPC	233	/**
	234	* snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
	235	* @substream: PCM substream
	236	*
	237	* This function can be used as the PCM pointer callback for dmaengine based PCM
	238	* driver implementations.
	239	*/
	240	snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
	241	{
	242	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	243	struct dma_tx_state state;
	244	enum dma_status status;
	245	unsigned int buf_size;
	246	unsigned int pos = 0;
	247
	248	status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
	249	if (status == DMA_IN_PROGRESS \|\| status == DMA_PAUSED) {
	250	buf_size = snd_pcm_lib_buffer_bytes(substream);
	251	if (state.residue > 0 && state.residue <= buf_size)
	252	pos = buf_size - state.residue;
	253	}
	254
	255	return bytes_to_frames(substream->runtime, pos);
	256	}
	257	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
	258
c999836d LPC	259	/**
	260	* snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM
	261	* @filter_fn: Filter function used to request the DMA channel
	262	* @filter_data: Data passed to the DMA filter function
	263	*
	264	* Returns NULL or the requested DMA channel.
	265	*
	266	* This function request a DMA channel for usage with dmaengine PCM.
	267	*/
	268	struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
7c1c1d4a	269	void *filter_data)
e7f73a16 LPC	270	{
	271	dma_cap_mask_t mask;
	272
	273	dma_cap_zero(mask);
	274	dma_cap_set(DMA_SLAVE, mask);
	275	dma_cap_set(DMA_CYCLIC, mask);
e7f73a16	276
7c1c1d4a	277	return dma_request_channel(mask, filter_fn, filter_data);
e7f73a16	278	}
c999836d	279	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel);
e7f73a16 LPC	280
	281	/**
	282	* snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
	283	* @substream: PCM substream
7c1c1d4a	284	* @chan: DMA channel to use for data transfers
e7f73a16 LPC	285	*
	286	* Returns 0 on success, a negative error code otherwise.
	287	*
7c1c1d4a LPC	288	* The function should usually be called from the pcm open callback. Note that
	289	* this function will use private_data field of the substream's runtime. So it
	290	* is not availabe to your pcm driver implementation.
e7f73a16 LPC	291	*/
e7f73a16 LPC	292	int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
7c1c1d4a	293	struct dma_chan *chan)
e7f73a16 LPC	294	{
	295	struct dmaengine_pcm_runtime_data *prtd;
	296	int ret;
	297
7c1c1d4a LPC	298	if (!chan)
	299	return -ENXIO;
	300
e7f73a16 LPC	301	ret = snd_pcm_hw_constraint_integer(substream->runtime,
	302	SNDRV_PCM_HW_PARAM_PERIODS);
	303	if (ret < 0)
	304	return ret;
	305
	306	prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
	307	if (!prtd)
	308	return -ENOMEM;
	309
7c1c1d4a	310	prtd->dma_chan = chan;
e7f73a16 LPC	311
	312	substream->runtime->private_data = prtd;
	313
	314	return 0;
	315	}
	316	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
	317
7c1c1d4a LPC	318	/**
	319	* snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel
	320	* @substream: PCM substream
	321	* @filter_fn: Filter function used to request the DMA channel
	322	* @filter_data: Data passed to the DMA filter function
	323	*
	324	* Returns 0 on success, a negative error code otherwise.
	325	*
	326	* This function will request a DMA channel using the passed filter function and
	327	* data. The function should usually be called from the pcm open callback. Note
	328	* that this function will use private_data field of the substream's runtime. So
	329	* it is not availabe to your pcm driver implementation.
	330	*/
	331	int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
	332	dma_filter_fn filter_fn, void *filter_data)
	333	{
	334	return snd_dmaengine_pcm_open(substream,
c999836d	335	snd_dmaengine_pcm_request_channel(filter_fn, filter_data));
7c1c1d4a LPC	336	}
	337	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
	338
e7f73a16 LPC	339	/**
	340	* snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
	341	* @substream: PCM substream
	342	*/
	343	int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
	344	{
	345	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	346
e7f73a16 LPC	347	kfree(prtd);
	348
	349	return 0;
	350	}
	351	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
cba69b4d	352
7c1c1d4a LPC	353	/**
	354	* snd_dmaengine_pcm_release_chan_close - Close a dmaengine based PCM substream and release channel
	355	* @substream: PCM substream
	356	*
	357	* Releases the DMA channel associated with the PCM substream.
	358	*/
	359	int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
	360	{
	361	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	362
	363	dma_release_channel(prtd->dma_chan);
	364
	365	return snd_dmaengine_pcm_close(substream);
	366	}
	367	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan);
	368
cba69b4d	369	MODULE_LICENSE("GPL");