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Commit e7f73a16 authored by Lars-Peter Clausen's avatar Lars-Peter Clausen Committed by Mark Brown
Browse files

ASoC: Add dmaengine PCM helper functions 



This patch adds a set of functions which are intended to be used when
implementing a dmaengine based sound PCM driver.

Signed-off-by: default avatarLars-Peter Clausen <lars@metafoo.de>
Tested-by: default avatarShawn Guo <shawn.guo@linaro.org>
Acked-by: default avatarVinod Koul <vinod.koul@linux.intel.com>
Signed-off-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
parent 1355ab14

include/sound/dmaengine_pcm.h

0 → 100644
+49 −0
Original line number Diff line number Diff line 
/*

 *  Copyright (C) 2012, 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.

 *

 */

#ifndef __SOUND_DMAENGINE_PCM_H__

#define __SOUND_DMAENGINE_PCM_H__



#include <sound/pcm.h>

#include <linux/dmaengine.h>



/**

 * snd_pcm_substream_to_dma_direction - Get dma_transfer_direction for a PCM

 *   substream

 * @substream: PCM substream

 */

static inline enum dma_transfer_direction

snd_pcm_substream_to_dma_direction(const struct snd_pcm_substream *substream)

{

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)

		return DMA_MEM_TO_DEV;

	else

		return DMA_DEV_TO_MEM;

}



void snd_dmaengine_pcm_set_data(struct snd_pcm_substream *substream, void *data);

void *snd_dmaengine_pcm_get_data(struct snd_pcm_substream *substream);



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);

int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd);

snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream);



int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,

	dma_filter_fn filter_fn, void *filter_data);

int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream);



struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream);



#endif

sound/soc/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -25,6 +25,9 @@ if SND_SOC 
config SND_SOC_AC97_BUS

	bool



config SND_SOC_DMAENGINE_PCM

	bool



# All the supported SoCs

source "sound/soc/atmel/Kconfig"

source "sound/soc/au1x/Kconfig"

sound/soc/Makefile

+3 −0
Original line number Diff line number Diff line 
snd-soc-core-objs := soc-core.o soc-dapm.o soc-jack.o soc-cache.o soc-utils.o

snd-soc-core-objs += soc-pcm.o soc-io.o



snd-soc-dmaengine-pcm-objs := soc-dmaengine-pcm.o

obj-$(CONFIG_SND_SOC_DMAENGINE_PCM) += snd-soc-dmaengine-pcm.o



obj-$(CONFIG_SND_SOC)	+= snd-soc-core.o

obj-$(CONFIG_SND_SOC)	+= codecs/

obj-$(CONFIG_SND_SOC)	+= atmel/

sound/soc/soc-dmaengine-pcm.c

0 → 100644
+287 −0
Original line number Diff line number Diff line 
/*

 *  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;



	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;



	direction = snd_pcm_substream_to_dma_direction(substream);



	desc = chan->device->device_prep_dma_cyclic(chan,

		substream->runtime->dma_addr,

		snd_pcm_lib_buffer_bytes(substream),

		snd_pcm_lib_period_bytes(substream), direction);



	if (!desc)

		return -ENOMEM;



	desc->callback = dmaengine_pcm_dma_complete;

	desc->callback_param = substream;

	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 - 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);

	return bytes_to_frames(substream->runtime, prtd->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_dmaeinge_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);