linux/sound/soc/mxs/mxs-pcm.c
Lars-Peter Clausen 9883ab229d ASoC: dmaengine-pcm: Rename and deprecate snd_dmaengine_pcm_pointer
Currently the sound dmaengine pcm helper functions implement the pcm_pointer
callback by trying to count the number of elapsed periods. This is done by
advancing the stream position in the dmaengine callback by one period.
Unfortunately there is no guarantee that the callback will be called for each
elapsed period. It may be possible that under high system load it is only called
once for multiple elapsed periods. This patch renames the current implementation
and documents its shortcomings and that it should not be used anymore in new
drivers.

The next patch will introduce a new snd_dmaengine_pcm_pointer which will be
implemented based on querying the current stream position from the dma device.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by Vinod Koul <vinod.koul@linux.intel.com>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2012-06-20 15:38:32 +01:00

236 lines
5.9 KiB
C

/*
* Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
*
* Based on sound/soc/imx/imx-pcm-dma-mx2.c
*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/dmaengine.h>
#include <linux/fsl/mxs-dma.h>
#include <sound/core.h>
#include <sound/initval.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/dmaengine_pcm.h>
#include "mxs-pcm.h"
struct mxs_pcm_dma_data {
struct mxs_dma_data dma_data;
struct mxs_pcm_dma_params *dma_params;
};
static struct snd_pcm_hardware snd_mxs_hardware = {
.info = SNDRV_PCM_INFO_MMAP |
SNDRV_PCM_INFO_MMAP_VALID |
SNDRV_PCM_INFO_PAUSE |
SNDRV_PCM_INFO_RESUME |
SNDRV_PCM_INFO_INTERLEAVED,
.formats = SNDRV_PCM_FMTBIT_S16_LE |
SNDRV_PCM_FMTBIT_S20_3LE |
SNDRV_PCM_FMTBIT_S24_LE,
.channels_min = 2,
.channels_max = 2,
.period_bytes_min = 32,
.period_bytes_max = 8192,
.periods_min = 1,
.periods_max = 52,
.buffer_bytes_max = 64 * 1024,
.fifo_size = 32,
};
static bool filter(struct dma_chan *chan, void *param)
{
struct mxs_pcm_dma_data *pcm_dma_data = param;
struct mxs_pcm_dma_params *dma_params = pcm_dma_data->dma_params;
if (!mxs_dma_is_apbx(chan))
return false;
if (chan->chan_id != dma_params->chan_num)
return false;
chan->private = &pcm_dma_data->dma_data;
return true;
}
static int snd_mxs_pcm_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params)
{
snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
return 0;
}
static int snd_mxs_open(struct snd_pcm_substream *substream)
{
struct snd_soc_pcm_runtime *rtd = substream->private_data;
struct mxs_pcm_dma_data *pcm_dma_data;
int ret;
pcm_dma_data = kzalloc(sizeof(*pcm_dma_data), GFP_KERNEL);
if (pcm_dma_data == NULL)
return -ENOMEM;
pcm_dma_data->dma_params = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
pcm_dma_data->dma_data.chan_irq = pcm_dma_data->dma_params->chan_irq;
ret = snd_dmaengine_pcm_open(substream, filter, pcm_dma_data);
if (ret) {
kfree(pcm_dma_data);
return ret;
}
snd_soc_set_runtime_hwparams(substream, &snd_mxs_hardware);
snd_dmaengine_pcm_set_data(substream, pcm_dma_data);
return 0;
}
static int snd_mxs_close(struct snd_pcm_substream *substream)
{
struct mxs_pcm_dma_data *pcm_dma_data = snd_dmaengine_pcm_get_data(substream);
snd_dmaengine_pcm_close(substream);
kfree(pcm_dma_data);
return 0;
}
static int snd_mxs_pcm_mmap(struct snd_pcm_substream *substream,
struct vm_area_struct *vma)
{
struct snd_pcm_runtime *runtime = substream->runtime;
return dma_mmap_writecombine(substream->pcm->card->dev, vma,
runtime->dma_area,
runtime->dma_addr,
runtime->dma_bytes);
}
static struct snd_pcm_ops mxs_pcm_ops = {
.open = snd_mxs_open,
.close = snd_mxs_close,
.ioctl = snd_pcm_lib_ioctl,
.hw_params = snd_mxs_pcm_hw_params,
.trigger = snd_dmaengine_pcm_trigger,
.pointer = snd_dmaengine_pcm_pointer_no_residue,
.mmap = snd_mxs_pcm_mmap,
};
static int mxs_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
{
struct snd_pcm_substream *substream = pcm->streams[stream].substream;
struct snd_dma_buffer *buf = &substream->dma_buffer;
size_t size = snd_mxs_hardware.buffer_bytes_max;
buf->dev.type = SNDRV_DMA_TYPE_DEV;
buf->dev.dev = pcm->card->dev;
buf->private_data = NULL;
buf->area = dma_alloc_writecombine(pcm->card->dev, size,
&buf->addr, GFP_KERNEL);
if (!buf->area)
return -ENOMEM;
buf->bytes = size;
return 0;
}
static u64 mxs_pcm_dmamask = DMA_BIT_MASK(32);
static int mxs_pcm_new(struct snd_soc_pcm_runtime *rtd)
{
struct snd_card *card = rtd->card->snd_card;
struct snd_pcm *pcm = rtd->pcm;
int ret = 0;
if (!card->dev->dma_mask)
card->dev->dma_mask = &mxs_pcm_dmamask;
if (!card->dev->coherent_dma_mask)
card->dev->coherent_dma_mask = DMA_BIT_MASK(32);
if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
ret = mxs_pcm_preallocate_dma_buffer(pcm,
SNDRV_PCM_STREAM_PLAYBACK);
if (ret)
goto out;
}
if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
ret = mxs_pcm_preallocate_dma_buffer(pcm,
SNDRV_PCM_STREAM_CAPTURE);
if (ret)
goto out;
}
out:
return ret;
}
static void mxs_pcm_free(struct snd_pcm *pcm)
{
struct snd_pcm_substream *substream;
struct snd_dma_buffer *buf;
int stream;
for (stream = 0; stream < 2; stream++) {
substream = pcm->streams[stream].substream;
if (!substream)
continue;
buf = &substream->dma_buffer;
if (!buf->area)
continue;
dma_free_writecombine(pcm->card->dev, buf->bytes,
buf->area, buf->addr);
buf->area = NULL;
}
}
static struct snd_soc_platform_driver mxs_soc_platform = {
.ops = &mxs_pcm_ops,
.pcm_new = mxs_pcm_new,
.pcm_free = mxs_pcm_free,
};
int __devinit mxs_pcm_platform_register(struct device *dev)
{
return snd_soc_register_platform(dev, &mxs_soc_platform);
}
EXPORT_SYMBOL_GPL(mxs_pcm_platform_register);
void __devexit mxs_pcm_platform_unregister(struct device *dev)
{
snd_soc_unregister_platform(dev);
}
EXPORT_SYMBOL_GPL(mxs_pcm_platform_unregister);
MODULE_LICENSE("GPL");