[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 = params_physical_width(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 == 24)
		buswidth = DMA_SLAVE_BUSWIDTH_3_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_async(prtd->dma_chan);
		break;
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
		dmaengine_pause(prtd->dma_chan);
		break;
	case SNDRV_PCM_TRIGGER_STOP:
		dmaengine_terminate_async(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 available 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 available 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);

	dmaengine_synchronize(prtd->dma_chan);
	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);

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

	return 0;
}
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
732814c8	68	bits = params_physical_width(params);
a655f75c TI	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;
75f850fc PU	75	else if (bits == 24)
75f850fc PU	76	buswidth = DMA_SLAVE_BUSWIDTH_3_BYTES;
a655f75c	77	else if (bits <= 32)
e7f73a16	78	buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
a655f75c TI	79	else
a655f75c TI	80	buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES;
e7f73a16 LPC	81
	82	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
	83	slave_config->direction = DMA_MEM_TO_DEV;
	84	slave_config->dst_addr_width = buswidth;
	85	} else {
	86	slave_config->direction = DMA_DEV_TO_MEM;
	87	slave_config->src_addr_width = buswidth;
	88	}
	89
5fa70f71 LPC	90	slave_config->device_fc = false;
5fa70f71 LPC	91
e7f73a16 LPC	92	return 0;
	93	}
	94	EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
	95
85c9f9c5 LPC	96	/**
	97	* snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config
	98	* using DAI DMA data.
	99	* @substream: PCM substream
	100	* @dma_data: DAI DMA data
	101	* @slave_config: DMA slave configuration
	102	*
	103	* Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and
	104	* slave_id fields of the DMA slave config from the same fields of the DAI DMA
	105	* data struct. The src and dst fields will be initialized depending on the
	106	* direction of the substream. If the substream is a playback stream the dst
	107	* fields will be initialized, if it is a capture stream the src fields will be
	108	* initialized. The {dst,src}_addr_width field will only be initialized if the
	109	* addr_width field of the DAI DMA data struct is not equal to
	110	* DMA_SLAVE_BUSWIDTH_UNDEFINED.
	111	*/
	112	void snd_dmaengine_pcm_set_config_from_dai_data(
	113	const struct snd_pcm_substream *substream,
	114	const struct snd_dmaengine_dai_dma_data *dma_data,
	115	struct dma_slave_config *slave_config)
	116	{
	117	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
	118	slave_config->dst_addr = dma_data->addr;
	119	slave_config->dst_maxburst = dma_data->maxburst;
	120	if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
	121	slave_config->dst_addr_width = dma_data->addr_width;
	122	} else {
	123	slave_config->src_addr = dma_data->addr;
	124	slave_config->src_maxburst = dma_data->maxburst;
	125	if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
	126	slave_config->src_addr_width = dma_data->addr_width;
	127	}
	128
	129	slave_config->slave_id = dma_data->slave_id;
	130	}
	131	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data);
	132
e7f73a16 LPC	133	static void dmaengine_pcm_dma_complete(void *arg)
	134	{
	135	struct snd_pcm_substream *substream = arg;
	136	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	137
	138	prtd->pos += snd_pcm_lib_period_bytes(substream);
	139	if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream))
	140	prtd->pos = 0;
	141
	142	snd_pcm_period_elapsed(substream);
	143	}
	144
	145	static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
	146	{
	147	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	148	struct dma_chan *chan = prtd->dma_chan;
	149	struct dma_async_tx_descriptor *desc;
	150	enum dma_transfer_direction direction;
e7736cde	151	unsigned long flags = DMA_CTRL_ACK;
e7f73a16 LPC	152
	153	direction = snd_pcm_substream_to_dma_direction(substream);
	154
e7736cde PU	155	if (!substream->runtime->no_period_wakeup)
	156	flags \|= DMA_PREP_INTERRUPT;
	157
7a08cf70	158	prtd->pos = 0;
41ba6b71	159	desc = dmaengine_prep_dma_cyclic(chan,
e7f73a16 LPC	160	substream->runtime->dma_addr,
e7f73a16 LPC	161	snd_pcm_lib_buffer_bytes(substream),
e7736cde	162	snd_pcm_lib_period_bytes(substream), direction, flags);
e7f73a16 LPC	163
	164	if (!desc)
	165	return -ENOMEM;
	166
	167	desc->callback = dmaengine_pcm_dma_complete;
	168	desc->callback_param = substream;
3528f27a	169	prtd->cookie = dmaengine_submit(desc);
e7f73a16 LPC	170
	171	return 0;
	172	}
	173
	174	/**
	175	* snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
	176	* @substream: PCM substream
	177	* @cmd: Trigger command
	178	*
	179	* Returns 0 on success, a negative error code otherwise.
	180	*
	181	* This function can be used as the PCM trigger callback for dmaengine based PCM
	182	* driver implementations.
	183	*/
	184	int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
	185	{
	186	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
02fb05a5	187	struct snd_pcm_runtime *runtime = substream->runtime;
e7f73a16 LPC	188	int ret;
	189
	190	switch (cmd) {
	191	case SNDRV_PCM_TRIGGER_START:
	192	ret = dmaengine_pcm_prepare_and_submit(substream);
	193	if (ret)
	194	return ret;
	195	dma_async_issue_pending(prtd->dma_chan);
	196	break;
	197	case SNDRV_PCM_TRIGGER_RESUME:
	198	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
	199	dmaengine_resume(prtd->dma_chan);
	200	break;
	201	case SNDRV_PCM_TRIGGER_SUSPEND:
02fb05a5 TB	202	if (runtime->info & SNDRV_PCM_INFO_PAUSE)
	203	dmaengine_pause(prtd->dma_chan);
	204	else
bc0e7345	205	dmaengine_terminate_async(prtd->dma_chan);
02fb05a5	206	break;
e7f73a16 LPC	207	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
	208	dmaengine_pause(prtd->dma_chan);
	209	break;
	210	case SNDRV_PCM_TRIGGER_STOP:
bc0e7345	211	dmaengine_terminate_async(prtd->dma_chan);
e7f73a16 LPC	212	break;
	213	default:
	214	return -EINVAL;
	215	}
	216
	217	return 0;
	218	}
	219	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
	220
	221	/**
9883ab22	222	* snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
e7f73a16 LPC	223	* @substream: PCM substream
e7f73a16 LPC	224	*
9883ab22 LPC	225	* This function is deprecated and should not be used by new drivers, as its
9883ab22 LPC	226	* results may be unreliable.
e7f73a16	227	*/
9883ab22	228	snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
e7f73a16 LPC	229	{
	230	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	231	return bytes_to_frames(substream->runtime, prtd->pos);
	232	}
9883ab22	233	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
e7f73a16	234
3528f27a LPC	235	/**
	236	* snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
	237	* @substream: PCM substream
	238	*
	239	* This function can be used as the PCM pointer callback for dmaengine based PCM
	240	* driver implementations.
	241	*/
	242	snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
	243	{
	244	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	245	struct dma_tx_state state;
	246	enum dma_status status;
	247	unsigned int buf_size;
	248	unsigned int pos = 0;
	249
	250	status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
	251	if (status == DMA_IN_PROGRESS \|\| status == DMA_PAUSED) {
	252	buf_size = snd_pcm_lib_buffer_bytes(substream);
	253	if (state.residue > 0 && state.residue <= buf_size)
	254	pos = buf_size - state.residue;
	255	}
	256
	257	return bytes_to_frames(substream->runtime, pos);
	258	}
	259	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
	260
c999836d LPC	261	/**
	262	* snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM
	263	* @filter_fn: Filter function used to request the DMA channel
	264	* @filter_data: Data passed to the DMA filter function
	265	*
	266	* Returns NULL or the requested DMA channel.
	267	*
	268	* This function request a DMA channel for usage with dmaengine PCM.
	269	*/
	270	struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
7c1c1d4a	271	void *filter_data)
e7f73a16 LPC	272	{
	273	dma_cap_mask_t mask;
	274
	275	dma_cap_zero(mask);
	276	dma_cap_set(DMA_SLAVE, mask);
	277	dma_cap_set(DMA_CYCLIC, mask);
e7f73a16	278
7c1c1d4a	279	return dma_request_channel(mask, filter_fn, filter_data);
e7f73a16	280	}
c999836d	281	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel);
e7f73a16 LPC	282
	283	/**
	284	* snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
	285	* @substream: PCM substream
7c1c1d4a	286	* @chan: DMA channel to use for data transfers
e7f73a16 LPC	287	*
	288	* Returns 0 on success, a negative error code otherwise.
	289	*
7c1c1d4a LPC	290	* The function should usually be called from the pcm open callback. Note that
7c1c1d4a LPC	291	* this function will use private_data field of the substream's runtime. So it
1a6ab46f	292	* is not available to your pcm driver implementation.
e7f73a16 LPC	293	*/
e7f73a16 LPC	294	int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
7c1c1d4a	295	struct dma_chan *chan)
e7f73a16 LPC	296	{
	297	struct dmaengine_pcm_runtime_data *prtd;
	298	int ret;
	299
7c1c1d4a LPC	300	if (!chan)
	301	return -ENXIO;
	302
e7f73a16 LPC	303	ret = snd_pcm_hw_constraint_integer(substream->runtime,
	304	SNDRV_PCM_HW_PARAM_PERIODS);
	305	if (ret < 0)
	306	return ret;
	307
	308	prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
	309	if (!prtd)
	310	return -ENOMEM;
	311
7c1c1d4a	312	prtd->dma_chan = chan;
e7f73a16 LPC	313
	314	substream->runtime->private_data = prtd;
	315
	316	return 0;
	317	}
	318	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
	319
7c1c1d4a LPC	320	/**
	321	* snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel
	322	* @substream: PCM substream
	323	* @filter_fn: Filter function used to request the DMA channel
	324	* @filter_data: Data passed to the DMA filter function
	325	*
	326	* Returns 0 on success, a negative error code otherwise.
	327	*
	328	* This function will request a DMA channel using the passed filter function and
	329	* data. The function should usually be called from the pcm open callback. Note
	330	* that this function will use private_data field of the substream's runtime. So
1a6ab46f	331	* it is not available to your pcm driver implementation.
7c1c1d4a LPC	332	*/
	333	int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
	334	dma_filter_fn filter_fn, void *filter_data)
	335	{
	336	return snd_dmaengine_pcm_open(substream,
c999836d	337	snd_dmaengine_pcm_request_channel(filter_fn, filter_data));
7c1c1d4a LPC	338	}
	339	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
	340
e7f73a16 LPC	341	/**
	342	* snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
	343	* @substream: PCM substream
	344	*/
	345	int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
	346	{
	347	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	348
bc0e7345	349	dmaengine_synchronize(prtd->dma_chan);
e7f73a16 LPC	350	kfree(prtd);
	351
	352	return 0;
	353	}
	354	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
cba69b4d	355
7c1c1d4a LPC	356	/**
	357	* snd_dmaengine_pcm_release_chan_close - Close a dmaengine based PCM substream and release channel
	358	* @substream: PCM substream
	359	*
	360	* Releases the DMA channel associated with the PCM substream.
	361	*/
	362	int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
	363	{
	364	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	365
bc0e7345	366	dmaengine_synchronize(prtd->dma_chan);
7c1c1d4a	367	dma_release_channel(prtd->dma_chan);
bc0e7345	368	kfree(prtd);
7c1c1d4a	369
bc0e7345	370	return 0;
7c1c1d4a LPC	371	}
	372	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan);
	373
cba69b4d	374	MODULE_LICENSE("GPL");