sound/soc/atmel/atmel-pcm-dma.c - linux - Git at Google

 /*
  * atmel-pcm-dma.c  --  ALSA PCM DMA support for the Atmel SoC.
  *
  *  Copyright (C) 2012 Atmel
  *
  * Author: Bo Shen <voice.shen@atmel.com>
  *
  * Based on atmel-pcm by:
  * Sedji Gaouaou <sedji.gaouaou@atmel.com>
  * Copyright 2008 Atmel
  *
  * 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.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */

 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/dma-mapping.h>
 #include <linux/dmaengine.h>
 #include <linux/atmel-ssc.h>
 #include <linux/platform_data/dma-atmel.h>

 #include <sound/core.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/soc.h>
 #include <sound/dmaengine_pcm.h>

 #include "atmel-pcm.h"

 /*--------------------------------------------------------------------------*\
  * Hardware definition
 \*--------------------------------------------------------------------------*/
 static const struct snd_pcm_hardware atmel_pcm_dma_hardware = {
 	.info			= SNDRV_PCM_INFO_MMAP |
 				  SNDRV_PCM_INFO_MMAP_VALID |
 				  SNDRV_PCM_INFO_INTERLEAVED |
 				  SNDRV_PCM_INFO_RESUME |
 				  SNDRV_PCM_INFO_PAUSE,
 	.formats		= SNDRV_PCM_FMTBIT_S16_LE,
 	.period_bytes_min	= 256,		/* lighting DMA overhead */
 	.period_bytes_max	= 2 * 0xffff,	/* if 2 bytes format */
 	.periods_min		= 8,
 	.periods_max		= 1024,		/* no limit */
 	.buffer_bytes_max	= ATMEL_SSC_DMABUF_SIZE,
 };

 /**
  * atmel_pcm_dma_irq: SSC interrupt handler for DMAENGINE enabled SSC
  *
  * We use DMAENGINE to send/receive data to/from SSC so this ISR is only to
  * check if any overrun occured.
  */
 static void atmel_pcm_dma_irq(u32 ssc_sr,
 	struct snd_pcm_substream *substream)
 {
 	struct atmel_pcm_dma_params *prtd;

 	prtd = snd_dmaengine_pcm_get_data(substream);

 	if (ssc_sr & prtd->mask->ssc_error) {
 		if (snd_pcm_running(substream))
 			pr_warn("atmel-pcm: buffer %s on %s (SSC_SR=%#x)\n",
 				substream->stream == SNDRV_PCM_STREAM_PLAYBACK
 				? "underrun" : "overrun", prtd->name,
 				ssc_sr);

 		/* stop RX and capture: will be enabled again at restart */
 		ssc_writex(prtd->ssc->regs, SSC_CR, prtd->mask->ssc_disable);
 		snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);

 		/* now drain RHR and read status to remove xrun condition */
 		ssc_readx(prtd->ssc->regs, SSC_RHR);
 		ssc_readx(prtd->ssc->regs, SSC_SR);
 	}
 }

 /*--------------------------------------------------------------------------*\
  * DMAENGINE operations
 \*--------------------------------------------------------------------------*/
 static bool filter(struct dma_chan *chan, void *slave)
 {
 	struct at_dma_slave *sl = slave;

 	if (sl->dma_dev == chan->device->dev) {
 		chan->private = sl;
 		return true;
 	} else {
 		return false;
 	}
 }

 static int atmel_pcm_configure_dma(struct snd_pcm_substream *substream,
 	struct snd_pcm_hw_params *params)
 {
 	struct atmel_pcm_dma_params *prtd;
 	struct ssc_device *ssc;
 	struct dma_chan *dma_chan;
 	struct dma_slave_config slave_config;
 	int ret;

 	prtd = snd_dmaengine_pcm_get_data(substream);
 	ssc = prtd->ssc;

 	ret = snd_hwparams_to_dma_slave_config(substream, params,
 			&slave_config);
 	if (ret) {
 		pr_err("atmel-pcm: hwparams to dma slave configure failed\n");
 		return ret;
 	}

 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		slave_config.dst_addr = (dma_addr_t)ssc->phybase + SSC_THR;
 		slave_config.dst_maxburst = 1;
 	} else {
 		slave_config.src_addr = (dma_addr_t)ssc->phybase + SSC_RHR;
 		slave_config.src_maxburst = 1;
 	}

 	slave_config.device_fc = false;

 	dma_chan = snd_dmaengine_pcm_get_chan(substream);
 	if (dmaengine_slave_config(dma_chan, &slave_config)) {
 		pr_err("atmel-pcm: failed to configure dma channel\n");
 		ret = -EBUSY;
 		return ret;
 	}

 	return 0;
 }

 static int atmel_pcm_hw_params(struct snd_pcm_substream *substream,
 	struct snd_pcm_hw_params *params)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct atmel_pcm_dma_params *prtd;
 	struct ssc_device *ssc;
 	struct at_dma_slave *sdata = NULL;
 	int ret;

 	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);

 	prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 	ssc = prtd->ssc;
 	if (ssc->pdev)
 		sdata = ssc->pdev->dev.platform_data;

 	ret = snd_dmaengine_pcm_open(substream, filter, sdata);
 	if (ret) {
 		pr_err("atmel-pcm: dmaengine pcm open failed\n");
 		return -EINVAL;
 	}

 	snd_dmaengine_pcm_set_data(substream, prtd);

 	ret = atmel_pcm_configure_dma(substream, params);
 	if (ret) {
 		pr_err("atmel-pcm: failed to configure dmai\n");
 		goto err;
 	}

 	prtd->dma_intr_handler = atmel_pcm_dma_irq;

 	return 0;
 err:
 	snd_dmaengine_pcm_close(substream);
 	return ret;
 }

 static int atmel_pcm_dma_prepare(struct snd_pcm_substream *substream)
 {
 	struct atmel_pcm_dma_params *prtd;

 	prtd = snd_dmaengine_pcm_get_data(substream);

 	ssc_writex(prtd->ssc->regs, SSC_IER, prtd->mask->ssc_error);
 	ssc_writex(prtd->ssc->regs, SSC_CR, prtd->mask->ssc_enable);

 	return 0;
 }

 static int atmel_pcm_open(struct snd_pcm_substream *substream)
 {
 	snd_soc_set_runtime_hwparams(substream, &atmel_pcm_dma_hardware);

 	return 0;
 }

 static int atmel_pcm_close(struct snd_pcm_substream *substream)
 {
 	snd_dmaengine_pcm_close(substream);

 	return 0;
 }

 static struct snd_pcm_ops atmel_pcm_ops = {
 	.open		= atmel_pcm_open,
 	.close		= atmel_pcm_close,
 	.ioctl		= snd_pcm_lib_ioctl,
 	.hw_params	= atmel_pcm_hw_params,
 	.prepare	= atmel_pcm_dma_prepare,
 	.trigger	= snd_dmaengine_pcm_trigger,
 	.pointer	= snd_dmaengine_pcm_pointer_no_residue,
 	.mmap		= atmel_pcm_mmap,
 };

 static struct snd_soc_platform_driver atmel_soc_platform = {
 	.ops		= &atmel_pcm_ops,
 	.pcm_new	= atmel_pcm_new,
 	.pcm_free	= atmel_pcm_free,
 };

 int atmel_pcm_dma_platform_register(struct device *dev)
 {
 	return snd_soc_register_platform(dev, &atmel_soc_platform);
 }
 EXPORT_SYMBOL(atmel_pcm_dma_platform_register);

 void atmel_pcm_dma_platform_unregister(struct device *dev)
 {
 	snd_soc_unregister_platform(dev);
 }
 EXPORT_SYMBOL(atmel_pcm_dma_platform_unregister);

 MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>");
 MODULE_DESCRIPTION("Atmel DMA based PCM module");
 MODULE_LICENSE("GPL");
	/*
	* atmel-pcm-dma.c -- ALSA PCM DMA support for the Atmel SoC.
	*
	* Copyright (C) 2012 Atmel
	*
	* Author: Bo Shen <voice.shen@atmel.com>
	*
	* Based on atmel-pcm by:
	* Sedji Gaouaou <sedji.gaouaou@atmel.com>
	* Copyright 2008 Atmel
	*
	* 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.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/dma-mapping.h>
	#include <linux/dmaengine.h>
	#include <linux/atmel-ssc.h>
	#include <linux/platform_data/dma-atmel.h>

	#include <sound/core.h>
	#include <sound/pcm.h>
	#include <sound/pcm_params.h>
	#include <sound/soc.h>
	#include <sound/dmaengine_pcm.h>

	#include "atmel-pcm.h"

	/--------------------------------------------------------------------------\
	* Hardware definition
	\--------------------------------------------------------------------------/
	static const struct snd_pcm_hardware atmel_pcm_dma_hardware = {
	.info = SNDRV_PCM_INFO_MMAP \|
	SNDRV_PCM_INFO_MMAP_VALID \|
	SNDRV_PCM_INFO_INTERLEAVED \|
	SNDRV_PCM_INFO_RESUME \|
	SNDRV_PCM_INFO_PAUSE,
	.formats = SNDRV_PCM_FMTBIT_S16_LE,
	.period_bytes_min = 256, /* lighting DMA overhead */
	.period_bytes_max = 2 * 0xffff, /* if 2 bytes format */
	.periods_min = 8,
	.periods_max = 1024, /* no limit */
	.buffer_bytes_max = ATMEL_SSC_DMABUF_SIZE,
	};

	/**
	* atmel_pcm_dma_irq: SSC interrupt handler for DMAENGINE enabled SSC
	*
	* We use DMAENGINE to send/receive data to/from SSC so this ISR is only to
	* check if any overrun occured.
	*/
	static void atmel_pcm_dma_irq(u32 ssc_sr,
	struct snd_pcm_substream *substream)
	{
	struct atmel_pcm_dma_params *prtd;

	prtd = snd_dmaengine_pcm_get_data(substream);

	if (ssc_sr & prtd->mask->ssc_error) {
	if (snd_pcm_running(substream))
	pr_warn("atmel-pcm: buffer %s on %s (SSC_SR=%#x)\n",
	substream->stream == SNDRV_PCM_STREAM_PLAYBACK
	? "underrun" : "overrun", prtd->name,
	ssc_sr);

	/* stop RX and capture: will be enabled again at restart */
	ssc_writex(prtd->ssc->regs, SSC_CR, prtd->mask->ssc_disable);
	snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);

	/* now drain RHR and read status to remove xrun condition */
	ssc_readx(prtd->ssc->regs, SSC_RHR);
	ssc_readx(prtd->ssc->regs, SSC_SR);
	}
	}

	/--------------------------------------------------------------------------\
	* DMAENGINE operations
	\--------------------------------------------------------------------------/
	static bool filter(struct dma_chan chan, void slave)
	{
	struct at_dma_slave *sl = slave;

	if (sl->dma_dev == chan->device->dev) {
	chan->private = sl;
	return true;
	} else {
	return false;
	}
	}

	static int atmel_pcm_configure_dma(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params)
	{
	struct atmel_pcm_dma_params *prtd;
	struct ssc_device *ssc;
	struct dma_chan *dma_chan;
	struct dma_slave_config slave_config;
	int ret;

	prtd = snd_dmaengine_pcm_get_data(substream);
	ssc = prtd->ssc;

	ret = snd_hwparams_to_dma_slave_config(substream, params,
	&slave_config);
	if (ret) {
	pr_err("atmel-pcm: hwparams to dma slave configure failed\n");
	return ret;
	}

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
	slave_config.dst_addr = (dma_addr_t)ssc->phybase + SSC_THR;
	slave_config.dst_maxburst = 1;
	} else {
	slave_config.src_addr = (dma_addr_t)ssc->phybase + SSC_RHR;
	slave_config.src_maxburst = 1;
	}

	slave_config.device_fc = false;

	dma_chan = snd_dmaengine_pcm_get_chan(substream);
	if (dmaengine_slave_config(dma_chan, &slave_config)) {
	pr_err("atmel-pcm: failed to configure dma channel\n");
	ret = -EBUSY;
	return ret;
	}

	return 0;
	}

	static int atmel_pcm_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params)
	{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct atmel_pcm_dma_params *prtd;
	struct ssc_device *ssc;
	struct at_dma_slave *sdata = NULL;
	int ret;

	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);

	prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
	ssc = prtd->ssc;
	if (ssc->pdev)
	sdata = ssc->pdev->dev.platform_data;

	ret = snd_dmaengine_pcm_open(substream, filter, sdata);
	if (ret) {
	pr_err("atmel-pcm: dmaengine pcm open failed\n");
	return -EINVAL;
	}

	snd_dmaengine_pcm_set_data(substream, prtd);

	ret = atmel_pcm_configure_dma(substream, params);
	if (ret) {
	pr_err("atmel-pcm: failed to configure dmai\n");
	goto err;
	}

	prtd->dma_intr_handler = atmel_pcm_dma_irq;

	return 0;
	err:
	snd_dmaengine_pcm_close(substream);
	return ret;
	}

	static int atmel_pcm_dma_prepare(struct snd_pcm_substream *substream)
	{
	struct atmel_pcm_dma_params *prtd;

	prtd = snd_dmaengine_pcm_get_data(substream);

	ssc_writex(prtd->ssc->regs, SSC_IER, prtd->mask->ssc_error);
	ssc_writex(prtd->ssc->regs, SSC_CR, prtd->mask->ssc_enable);

	return 0;
	}

	static int atmel_pcm_open(struct snd_pcm_substream *substream)
	{
	snd_soc_set_runtime_hwparams(substream, &atmel_pcm_dma_hardware);

	return 0;
	}

	static int atmel_pcm_close(struct snd_pcm_substream *substream)
	{
	snd_dmaengine_pcm_close(substream);

	return 0;
	}

	static struct snd_pcm_ops atmel_pcm_ops = {
	.open = atmel_pcm_open,
	.close = atmel_pcm_close,
	.ioctl = snd_pcm_lib_ioctl,
	.hw_params = atmel_pcm_hw_params,
	.prepare = atmel_pcm_dma_prepare,
	.trigger = snd_dmaengine_pcm_trigger,
	.pointer = snd_dmaengine_pcm_pointer_no_residue,
	.mmap = atmel_pcm_mmap,
	};

	static struct snd_soc_platform_driver atmel_soc_platform = {
	.ops = &atmel_pcm_ops,
	.pcm_new = atmel_pcm_new,
	.pcm_free = atmel_pcm_free,
	};

	int atmel_pcm_dma_platform_register(struct device *dev)
	{
	return snd_soc_register_platform(dev, &atmel_soc_platform);
	}
	EXPORT_SYMBOL(atmel_pcm_dma_platform_register);

	void atmel_pcm_dma_platform_unregister(struct device *dev)
	{
	snd_soc_unregister_platform(dev);
	}
	EXPORT_SYMBOL(atmel_pcm_dma_platform_unregister);

	MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>");
	MODULE_DESCRIPTION("Atmel DMA based PCM module");
	MODULE_LICENSE("GPL");