/*
* 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 <linux/of_dma.h>
#include <sound/dmaengine_pcm.h>
struct dmaengine_pcm {
struct dma_chan *chan[SNDRV_PCM_STREAM_CAPTURE + 1];
const struct snd_dmaengine_pcm_config *config;
struct snd_soc_platform platform;
};
static struct dmaengine_pcm *soc_platform_to_pcm(struct snd_soc_platform *p)
{
return container_of(p, struct dmaengine_pcm, platform);
}
/**
* 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);
struct dma_slave_config slave_config;
int ret;
if (pcm->config->prepare_slave_config) {
ret = pcm->config->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_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 = snd_soc_set_runtime_hwparams(substream,
pcm->config->pcm_hardware);
if (ret)
return ret;
return snd_dmaengine_pcm_open(substream, chan);
}
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;
}
static void dmaengine_pcm_free(struct snd_pcm *pcm)
{
snd_pcm_lib_preallocate_free_for_all(pcm);
}
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 snd_pcm_substream *substream;
unsigned int i;
int ret;
for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
substream = rtd->pcm->streams[i].substream;
if (!substream)
continue;
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,
dmaengine_dma_dev(pcm, substream),
config->prealloc_buffer_size,
config->pcm_hardware->buffer_bytes_max);
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,
};
static const char * const dmaengine_pcm_dma_channel_names[] = {
[SNDRV_PCM_STREAM_PLAYBACK] = "tx",
[SNDRV_PCM_STREAM_CAPTURE] = "rx",
};
/**
* 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;
unsigned int i;
if (!dev->of_node)
return -EINVAL;
pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
if (!pcm)
return -ENOMEM;
pcm->config = config;
for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
pcm->chan[i] = of_dma_request_slave_channel(dev->of_node,
dmaengine_pcm_dma_channel_names[i]);
}
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]);
}
snd_soc_remove_platform(platform);
kfree(pcm);
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
MODULE_LICENSE("GPL");
