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

/*
 *  Copyright (C) 2013, Analog Devices Inc.
 *	Author: Lars-Peter Clausen <lars@metafoo.de>
 *
 *  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 <linux/dma-mapping.h>
#include <linux/of.h>

#include <sound/dmaengine_pcm.h>

struct dmaengine_pcm {
	struct dma_chan *chan[SNDRV_PCM_STREAM_LAST + 1];
	const struct snd_dmaengine_pcm_config *config;
	struct snd_soc_platform platform;
	unsigned int flags;
};

static struct dmaengine_pcm *soc_platform_to_pcm(struct snd_soc_platform *p)
{
	return container_of(p, struct dmaengine_pcm, platform);
}

static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm,
	struct snd_pcm_substream *substream)
{
	if (!pcm->chan[substream->stream])
		return NULL;

	return pcm->chan[substream->stream]->device->dev;
}

/**
 * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback
 * @substream: PCM substream
 * @params: hw_params
 * @slave_config: DMA slave config to prepare
 *
 * This function can be used as a generic prepare_slave_config callback for
 * platforms which make use of the snd_dmaengine_dai_dma_data struct for their
 * DAI DMA data. Internally the function will first call
 * snd_hwparams_to_dma_slave_config to fill in the slave config based on the
 * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the
 * remaining fields based on the DAI DMA data.
 */
int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_dmaengine_dai_dma_data *dma_data;
	int ret;

	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

	ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config);
	if (ret)
		return ret;

	snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data,
		slave_config);

	return 0;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config);

static int dmaengine_pcm_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
	struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
	int (*prepare_slave_config)(struct snd_pcm_substream *substream,
			struct snd_pcm_hw_params *params,
			struct dma_slave_config *slave_config);
	struct dma_slave_config slave_config;
	int ret;

	if (!pcm->config)
		prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config;
	else
		prepare_slave_config = pcm->config->prepare_slave_config;

	if (prepare_slave_config) {
		ret = prepare_slave_config(substream, params, &slave_config);
		if (ret)
			return ret;

		ret = dmaengine_slave_config(chan, &slave_config);
		if (ret)
			return ret;
	}

	return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
}

static int dmaengine_pcm_set_runtime_hwparams(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
	struct device *dma_dev = dmaengine_dma_dev(pcm, substream);
	struct dma_chan *chan = pcm->chan[substream->stream];
	struct snd_dmaengine_dai_dma_data *dma_data;
	struct dma_slave_caps dma_caps;
	struct snd_pcm_hardware hw;
	int ret;

	if (pcm->config && pcm->config->pcm_hardware)
		return snd_soc_set_runtime_hwparams(substream,
				pcm->config->pcm_hardware);

	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

	memset(&hw, 0, sizeof(hw));
	hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
			SNDRV_PCM_INFO_INTERLEAVED;
	hw.periods_min = 2;
	hw.periods_max = UINT_MAX;
	hw.period_bytes_min = 256;
	hw.period_bytes_max = dma_get_max_seg_size(dma_dev);
	hw.buffer_bytes_max = SIZE_MAX;
	hw.fifo_size = dma_data->fifo_size;

	ret = dma_get_slave_caps(chan, &dma_caps);
	if (ret == 0) {
		if (dma_caps.cmd_pause)
			hw.info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME;
	}

	return snd_soc_set_runtime_hwparams(substream, &hw);
}

static int dmaengine_pcm_open(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
	struct dma_chan *chan = pcm->chan[substream->stream];
	int ret;

	ret = dmaengine_pcm_set_runtime_hwparams(substream);
	if (ret)
		return ret;

	return snd_dmaengine_pcm_open(substream, chan);
}

static void dmaengine_pcm_free(struct snd_pcm *pcm)
{
	snd_pcm_lib_preallocate_free_for_all(pcm);
}

static struct dma_chan *dmaengine_pcm_compat_request_channel(
	struct snd_soc_pcm_runtime *rtd,
	struct snd_pcm_substream *substream)
{
	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
	struct snd_dmaengine_dai_dma_data *dma_data;

	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

	if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
		return pcm->chan[0];

	if (pcm->config->compat_request_channel)
		return pcm->config->compat_request_channel(rtd, substream);

	return snd_dmaengine_pcm_request_channel(pcm->config->compat_filter_fn,
						 dma_data->filter_data);
}

static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd)
{
	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
	const struct snd_dmaengine_pcm_config *config = pcm->config;
	struct device *dev = rtd->platform->dev;
	struct snd_dmaengine_dai_dma_data *dma_data;
	struct snd_pcm_substream *substream;
	size_t prealloc_buffer_size;
	size_t max_buffer_size;
	unsigned int i;
	int ret;

	if (config && config->prealloc_buffer_size) {
		prealloc_buffer_size = config->prealloc_buffer_size;
		max_buffer_size = config->pcm_hardware->buffer_bytes_max;
	} else {
		prealloc_buffer_size = 512 * 1024;
		max_buffer_size = SIZE_MAX;
	}


	for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
		substream = rtd->pcm->streams[i].substream;
		if (!substream)
			continue;

		dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

		if (!pcm->chan[i] &&
		    (pcm->flags & SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME))
			pcm->chan[i] = dma_request_slave_channel(dev,
				dma_data->chan_name);

		if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {
			pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd,
				substream);
		}

		if (!pcm->chan[i]) {
			dev_err(rtd->platform->dev,
				"Missing dma channel for stream: %d\n", i);
			ret = -EINVAL;
			goto err_free;
		}

		ret = snd_pcm_lib_preallocate_pages(substream,
				SNDRV_DMA_TYPE_DEV_IRAM,
				dmaengine_dma_dev(pcm, substream),
				prealloc_buffer_size,
				max_buffer_size);
		if (ret)
			goto err_free;
	}

	return 0;

err_free:
	dmaengine_pcm_free(rtd->pcm);
	return ret;
}

static const struct snd_pcm_ops dmaengine_pcm_ops = {
	.open		= dmaengine_pcm_open,
	.close		= snd_dmaengine_pcm_close,
	.ioctl		= snd_pcm_lib_ioctl,
	.hw_params	= dmaengine_pcm_hw_params,
	.hw_free	= snd_pcm_lib_free_pages,
	.trigger	= snd_dmaengine_pcm_trigger,
	.pointer	= snd_dmaengine_pcm_pointer,
};

static const struct snd_soc_platform_driver dmaengine_pcm_platform = {
	.ops		= &dmaengine_pcm_ops,
	.pcm_new	= dmaengine_pcm_new,
	.pcm_free	= dmaengine_pcm_free,
	.probe_order	= SND_SOC_COMP_ORDER_LATE,
};

static const struct snd_pcm_ops dmaengine_no_residue_pcm_ops = {
	.open		= dmaengine_pcm_open,
	.close		= snd_dmaengine_pcm_close,
	.ioctl		= snd_pcm_lib_ioctl,
	.hw_params	= dmaengine_pcm_hw_params,
	.hw_free	= snd_pcm_lib_free_pages,
	.trigger	= snd_dmaengine_pcm_trigger,
	.pointer	= snd_dmaengine_pcm_pointer_no_residue,
};

static const struct snd_soc_platform_driver dmaengine_no_residue_pcm_platform = {
	.ops		= &dmaengine_no_residue_pcm_ops,
	.pcm_new	= dmaengine_pcm_new,
	.pcm_free	= dmaengine_pcm_free,
	.probe_order	= SND_SOC_COMP_ORDER_LATE,
};

static const char * const dmaengine_pcm_dma_channel_names[] = {
	[SNDRV_PCM_STREAM_PLAYBACK] = "tx",
	[SNDRV_PCM_STREAM_CAPTURE] = "rx",
};

static void dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
	struct device *dev)
{
	unsigned int i;

	if ((pcm->flags & (SND_DMAENGINE_PCM_FLAG_NO_DT |
			   SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) ||
	    !dev->of_node)
		return;

	if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) {
		pcm->chan[0] = dma_request_slave_channel(dev, "rx-tx");
		pcm->chan[1] = pcm->chan[0];
	} else {
		for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
			pcm->chan[i] = dma_request_slave_channel(dev,
					dmaengine_pcm_dma_channel_names[i]);
		}
	}
}

/**
 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device
 * @dev: The parent device for the PCM device
 * @config: Platform specific PCM configuration
 * @flags: Platform specific quirks
 */
int snd_dmaengine_pcm_register(struct device *dev,
	const struct snd_dmaengine_pcm_config *config, unsigned int flags)
{
	struct dmaengine_pcm *pcm;

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

	pcm->config = config;
	pcm->flags = flags;

	dmaengine_pcm_request_chan_of(pcm, dev);

	if (flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
		return snd_soc_add_platform(dev, &pcm->platform,
				&dmaengine_no_residue_pcm_platform);
	else
		return snd_soc_add_platform(dev, &pcm->platform,
				&dmaengine_pcm_platform);
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register);

/**
 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device
 * @dev: Parent device the PCM was register with
 *
 * Removes a dmaengine based PCM device previously registered with
 * snd_dmaengine_pcm_register.
 */
void snd_dmaengine_pcm_unregister(struct device *dev)
{
	struct snd_soc_platform *platform;
	struct dmaengine_pcm *pcm;
	unsigned int i;

	platform = snd_soc_lookup_platform(dev);
	if (!platform)
		return;

	pcm = soc_platform_to_pcm(platform);

	for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
		if (pcm->chan[i]) {
			dma_release_channel(pcm->chan[i]);
			if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
				break;
		}
	}

	snd_soc_remove_platform(platform);
	kfree(pcm);
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);

MODULE_LICENSE("GPL");
Commit	Line	Data
28c4468b LPC	1	/*
	2	* Copyright (C) 2013, Analog Devices Inc.
	3	* Author: Lars-Peter Clausen <lars@metafoo.de>
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms of the GNU General Public License as published by the
	7	* Free Software Foundation; either version 2 of the License, or (at your
	8	* option) any later version.
	9	*
	10	* You should have received a copy of the GNU General Public License along
	11	* with this program; if not, write to the Free Software Foundation, Inc.,
	12	* 675 Mass Ave, Cambridge, MA 02139, USA.
	13	*
	14	*/
	15	#include <linux/module.h>
	16	#include <linux/init.h>
	17	#include <linux/dmaengine.h>
	18	#include <linux/slab.h>
	19	#include <sound/pcm.h>
	20	#include <sound/pcm_params.h>
	21	#include <sound/soc.h>
	22	#include <linux/dma-mapping.h>
	23	#include <linux/of.h>
28c4468b LPC	24
	25	#include <sound/dmaengine_pcm.h>
	26
	27	struct dmaengine_pcm {
f82bf8e2	28	struct dma_chan *chan[SNDRV_PCM_STREAM_LAST + 1];
28c4468b LPC	29	const struct snd_dmaengine_pcm_config *config;
28c4468b LPC	30	struct snd_soc_platform platform;
d1e1406c	31	unsigned int flags;
28c4468b LPC	32	};
	33
	34	static struct dmaengine_pcm soc_platform_to_pcm(struct snd_soc_platform p)
	35	{
	36	return container_of(p, struct dmaengine_pcm, platform);
	37	}
	38
c0de42bf LPC	39	static struct device dmaengine_dma_dev(struct dmaengine_pcm pcm,
	40	struct snd_pcm_substream *substream)
	41	{
	42	if (!pcm->chan[substream->stream])
	43	return NULL;
	44
	45	return pcm->chan[substream->stream]->device->dev;
	46	}
	47
28c4468b LPC	48	/**
	49	* snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback
	50	* @substream: PCM substream
	51	* @params: hw_params
	52	* @slave_config: DMA slave config to prepare
	53	*
	54	* This function can be used as a generic prepare_slave_config callback for
	55	* platforms which make use of the snd_dmaengine_dai_dma_data struct for their
	56	* DAI DMA data. Internally the function will first call
	57	* snd_hwparams_to_dma_slave_config to fill in the slave config based on the
	58	* hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the
	59	* remaining fields based on the DAI DMA data.
	60	*/
	61	int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
	62	struct snd_pcm_hw_params params, struct dma_slave_config slave_config)
	63	{
	64	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	65	struct snd_dmaengine_dai_dma_data *dma_data;
	66	int ret;
	67
	68	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
	69
	70	ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config);
	71	if (ret)
	72	return ret;
	73
	74	snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data,
	75	slave_config);
	76
	77	return 0;
	78	}
	79	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config);
	80
	81	static int dmaengine_pcm_hw_params(struct snd_pcm_substream *substream,
	82	struct snd_pcm_hw_params *params)
	83	{
	84	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	85	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
	86	struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
fa654e08 LPC	87	int (prepare_slave_config)(struct snd_pcm_substream substream,
	88	struct snd_pcm_hw_params *params,
	89	struct dma_slave_config *slave_config);
28c4468b LPC	90	struct dma_slave_config slave_config;
	91	int ret;
	92
fa654e08 LPC	93	if (!pcm->config)
	94	prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config;
	95	else
	96	prepare_slave_config = pcm->config->prepare_slave_config;
	97
	98	if (prepare_slave_config) {
	99	ret = prepare_slave_config(substream, params, &slave_config);
28c4468b LPC	100	if (ret)
	101	return ret;
	102
	103	ret = dmaengine_slave_config(chan, &slave_config);
	104	if (ret)
	105	return ret;
	106	}
	107
	108	return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
	109	}
	110
c0de42bf	111	static int dmaengine_pcm_set_runtime_hwparams(struct snd_pcm_substream *substream)
28c4468b LPC	112	{
	113	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	114	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
c0de42bf	115	struct device *dma_dev = dmaengine_dma_dev(pcm, substream);
28c4468b	116	struct dma_chan *chan = pcm->chan[substream->stream];
c0de42bf LPC	117	struct snd_dmaengine_dai_dma_data *dma_data;
	118	struct dma_slave_caps dma_caps;
	119	struct snd_pcm_hardware hw;
28c4468b LPC	120	int ret;
28c4468b LPC	121
fa654e08	122	if (pcm->config && pcm->config->pcm_hardware)
c0de42bf	123	return snd_soc_set_runtime_hwparams(substream,
28c4468b	124	pcm->config->pcm_hardware);
28c4468b	125
c0de42bf LPC	126	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
	127
	128	memset(&hw, 0, sizeof(hw));
	129	hw.info = SNDRV_PCM_INFO_MMAP \| SNDRV_PCM_INFO_MMAP_VALID \|
	130	SNDRV_PCM_INFO_INTERLEAVED;
	131	hw.periods_min = 2;
	132	hw.periods_max = UINT_MAX;
	133	hw.period_bytes_min = 256;
	134	hw.period_bytes_max = dma_get_max_seg_size(dma_dev);
	135	hw.buffer_bytes_max = SIZE_MAX;
	136	hw.fifo_size = dma_data->fifo_size;
	137
	138	ret = dma_get_slave_caps(chan, &dma_caps);
	139	if (ret == 0) {
	140	if (dma_caps.cmd_pause)
	141	hw.info \|= SNDRV_PCM_INFO_PAUSE \| SNDRV_PCM_INFO_RESUME;
	142	}
	143
	144	return snd_soc_set_runtime_hwparams(substream, &hw);
28c4468b LPC	145	}
28c4468b LPC	146
c0de42bf	147	static int dmaengine_pcm_open(struct snd_pcm_substream *substream)
28c4468b	148	{
c0de42bf LPC	149	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	150	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
	151	struct dma_chan *chan = pcm->chan[substream->stream];
	152	int ret;
28c4468b	153
c0de42bf LPC	154	ret = dmaengine_pcm_set_runtime_hwparams(substream);
	155	if (ret)
	156	return ret;
	157
	158	return snd_dmaengine_pcm_open(substream, chan);
28c4468b LPC	159	}
	160
	161	static void dmaengine_pcm_free(struct snd_pcm *pcm)
	162	{
	163	snd_pcm_lib_preallocate_free_for_all(pcm);
	164	}
	165
c999836d LPC	166	static struct dma_chan *dmaengine_pcm_compat_request_channel(
	167	struct snd_soc_pcm_runtime *rtd,
	168	struct snd_pcm_substream *substream)
	169	{
	170	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
90130d2e MB	171	struct snd_dmaengine_dai_dma_data *dma_data;
	172
	173	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
c999836d	174
d1e1406c LPC	175	if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
	176	return pcm->chan[0];
	177
c999836d LPC	178	if (pcm->config->compat_request_channel)
	179	return pcm->config->compat_request_channel(rtd, substream);
	180
	181	return snd_dmaengine_pcm_request_channel(pcm->config->compat_filter_fn,
90130d2e	182	dma_data->filter_data);
c999836d LPC	183	}
c999836d LPC	184
28c4468b LPC	185	static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd)
	186	{
	187	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
	188	const struct snd_dmaengine_pcm_config *config = pcm->config;
ea73b7dd MB	189	struct device *dev = rtd->platform->dev;
ea73b7dd MB	190	struct snd_dmaengine_dai_dma_data *dma_data;
28c4468b	191	struct snd_pcm_substream *substream;
fa654e08 LPC	192	size_t prealloc_buffer_size;
fa654e08 LPC	193	size_t max_buffer_size;
28c4468b LPC	194	unsigned int i;
	195	int ret;
	196
fa654e08 LPC	197	if (config && config->prealloc_buffer_size) {
	198	prealloc_buffer_size = config->prealloc_buffer_size;
	199	max_buffer_size = config->pcm_hardware->buffer_bytes_max;
	200	} else {
	201	prealloc_buffer_size = 512 * 1024;
	202	max_buffer_size = SIZE_MAX;
	203	}
	204
	205
28c4468b LPC	206	for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
	207	substream = rtd->pcm->streams[i].substream;
	208	if (!substream)
	209	continue;
	210
ea73b7dd MB	211	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
	212
	213	if (!pcm->chan[i] &&
	214	(pcm->flags & SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME))
	215	pcm->chan[i] = dma_request_slave_channel(dev,
	216	dma_data->chan_name);
	217
d1e1406c	218	if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {
c999836d LPC	219	pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd,
	220	substream);
	221	}
	222
28c4468b LPC	223	if (!pcm->chan[i]) {
	224	dev_err(rtd->platform->dev,
	225	"Missing dma channel for stream: %d\n", i);
	226	ret = -EINVAL;
	227	goto err_free;
	228	}
	229
	230	ret = snd_pcm_lib_preallocate_pages(substream,
ca2b0295	231	SNDRV_DMA_TYPE_DEV_IRAM,
28c4468b	232	dmaengine_dma_dev(pcm, substream),
fa654e08 LPC	233	prealloc_buffer_size,
fa654e08 LPC	234	max_buffer_size);
28c4468b LPC	235	if (ret)
	236	goto err_free;
	237	}
	238
	239	return 0;
	240
	241	err_free:
	242	dmaengine_pcm_free(rtd->pcm);
	243	return ret;
	244	}
	245
	246	static const struct snd_pcm_ops dmaengine_pcm_ops = {
	247	.open = dmaengine_pcm_open,
	248	.close = snd_dmaengine_pcm_close,
	249	.ioctl = snd_pcm_lib_ioctl,
	250	.hw_params = dmaengine_pcm_hw_params,
	251	.hw_free = snd_pcm_lib_free_pages,
	252	.trigger = snd_dmaengine_pcm_trigger,
	253	.pointer = snd_dmaengine_pcm_pointer,
	254	};
	255
	256	static const struct snd_soc_platform_driver dmaengine_pcm_platform = {
	257	.ops = &dmaengine_pcm_ops,
	258	.pcm_new = dmaengine_pcm_new,
	259	.pcm_free = dmaengine_pcm_free,
c999836d	260	.probe_order = SND_SOC_COMP_ORDER_LATE,
28c4468b LPC	261	};
28c4468b LPC	262
610f7800 LPC	263	static const struct snd_pcm_ops dmaengine_no_residue_pcm_ops = {
	264	.open = dmaengine_pcm_open,
	265	.close = snd_dmaengine_pcm_close,
	266	.ioctl = snd_pcm_lib_ioctl,
	267	.hw_params = dmaengine_pcm_hw_params,
	268	.hw_free = snd_pcm_lib_free_pages,
	269	.trigger = snd_dmaengine_pcm_trigger,
	270	.pointer = snd_dmaengine_pcm_pointer_no_residue,
	271	};
	272
	273	static const struct snd_soc_platform_driver dmaengine_no_residue_pcm_platform = {
	274	.ops = &dmaengine_no_residue_pcm_ops,
	275	.pcm_new = dmaengine_pcm_new,
	276	.pcm_free = dmaengine_pcm_free,
	277	.probe_order = SND_SOC_COMP_ORDER_LATE,
	278	};
	279
28c4468b LPC	280	static const char * const dmaengine_pcm_dma_channel_names[] = {
	281	[SNDRV_PCM_STREAM_PLAYBACK] = "tx",
	282	[SNDRV_PCM_STREAM_CAPTURE] = "rx",
	283	};
	284
d1e1406c	285	static void dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
6f1fd93e	286	struct device *dev)
d1e1406c LPC	287	{
	288	unsigned int i;
	289
ea73b7dd MB	290	if ((pcm->flags & (SND_DMAENGINE_PCM_FLAG_NO_DT \|
	291	SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) \|\|
	292	!dev->of_node)
d1e1406c LPC	293	return;
	294
	295	if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) {
6f1fd93e	296	pcm->chan[0] = dma_request_slave_channel(dev, "rx-tx");
d1e1406c LPC	297	pcm->chan[1] = pcm->chan[0];
	298	} else {
	299	for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
6f1fd93e	300	pcm->chan[i] = dma_request_slave_channel(dev,
d1e1406c LPC	301	dmaengine_pcm_dma_channel_names[i]);
	302	}
	303	}
	304	}
	305
28c4468b LPC	306	/**
	307	* snd_dmaengine_pcm_register - Register a dmaengine based PCM device
	308	* @dev: The parent device for the PCM device
	309	* @config: Platform specific PCM configuration
	310	* @flags: Platform specific quirks
	311	*/
	312	int snd_dmaengine_pcm_register(struct device *dev,
	313	const struct snd_dmaengine_pcm_config *config, unsigned int flags)
	314	{
	315	struct dmaengine_pcm *pcm;
28c4468b	316
28c4468b LPC	317	pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
	318	if (!pcm)
	319	return -ENOMEM;
	320
	321	pcm->config = config;
d1e1406c	322	pcm->flags = flags;
28c4468b	323
6f1fd93e	324	dmaengine_pcm_request_chan_of(pcm, dev);
28c4468b	325
610f7800 LPC	326	if (flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
	327	return snd_soc_add_platform(dev, &pcm->platform,
	328	&dmaengine_no_residue_pcm_platform);
	329	else
	330	return snd_soc_add_platform(dev, &pcm->platform,
28c4468b LPC	331	&dmaengine_pcm_platform);
	332	}
	333	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register);
	334
	335	/**
	336	* snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device
	337	* @dev: Parent device the PCM was register with
	338	*
	339	* Removes a dmaengine based PCM device previously registered with
	340	* snd_dmaengine_pcm_register.
	341	*/
	342	void snd_dmaengine_pcm_unregister(struct device *dev)
	343	{
	344	struct snd_soc_platform *platform;
	345	struct dmaengine_pcm *pcm;
	346	unsigned int i;
	347
	348	platform = snd_soc_lookup_platform(dev);
	349	if (!platform)
	350	return;
	351
	352	pcm = soc_platform_to_pcm(platform);
	353
	354	for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
d1e1406c	355	if (pcm->chan[i]) {
28c4468b	356	dma_release_channel(pcm->chan[i]);
d1e1406c LPC	357	if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
	358	break;
	359	}
28c4468b LPC	360	}
	361
	362	snd_soc_remove_platform(platform);
	363	kfree(pcm);
	364	}
	365	EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
	366
	367	MODULE_LICENSE("GPL");