ASoC: dmaengine_pcm: add processing support

Allow dmaengine client to optionally register a processing callback.
This callback is intended to apply processing
on samples in buffer copied from/to user space, before/after DMA transfer.

Signed-off-by: Olivier Moysan <olivier.moysan@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Olivier Moysan 2018-02-19 16:00:36 +01:00 committed by Mark Brown
parent 7ed310bd51
commit 78648092ef
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
2 changed files with 63 additions and 2 deletions

View File

@ -140,6 +140,9 @@ struct snd_dmaengine_pcm_config {
struct dma_chan *(*compat_request_channel)(
struct snd_soc_pcm_runtime *rtd,
struct snd_pcm_substream *substream);
int (*process)(struct snd_pcm_substream *substream,
int channel, unsigned long hwoff,
void *buf, unsigned long bytes);
dma_filter_fn compat_filter_fn;
struct device *dma_dev;
const char *chan_names[SNDRV_PCM_STREAM_LAST + 1];

View File

@ -341,6 +341,41 @@ static snd_pcm_uframes_t dmaengine_pcm_pointer(
return snd_dmaengine_pcm_pointer(substream);
}
static int dmaengine_copy_user(struct snd_pcm_substream *substream,
int channel, unsigned long hwoff,
void *buf, unsigned long bytes)
{
struct snd_soc_pcm_runtime *rtd = substream->private_data;
struct snd_soc_component *component =
snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME);
struct snd_pcm_runtime *runtime = substream->runtime;
struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
int (*process)(struct snd_pcm_substream *substream,
int channel, unsigned long hwoff,
void *buf, unsigned long bytes) = pcm->config->process;
bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
void *dma_ptr = runtime->dma_area + hwoff +
channel * (runtime->dma_bytes / runtime->channels);
int ret;
if (is_playback)
if (copy_from_user(dma_ptr, (void __user *)buf, bytes))
return -EFAULT;
if (process) {
ret = process(substream, channel, hwoff,
(void __user *)buf, bytes);
if (ret < 0)
return ret;
}
if (!is_playback)
if (copy_to_user((void __user *)buf, dma_ptr, bytes))
return -EFAULT;
return 0;
}
static const struct snd_pcm_ops dmaengine_pcm_ops = {
.open = dmaengine_pcm_open,
.close = snd_dmaengine_pcm_close,
@ -351,6 +386,17 @@ static const struct snd_pcm_ops dmaengine_pcm_ops = {
.pointer = dmaengine_pcm_pointer,
};
static const struct snd_pcm_ops dmaengine_pcm_process_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 = dmaengine_pcm_pointer,
.copy_user = dmaengine_copy_user,
};
static const struct snd_soc_component_driver dmaengine_pcm_component = {
.name = SND_DMAENGINE_PCM_DRV_NAME,
.probe_order = SND_SOC_COMP_ORDER_LATE,
@ -358,6 +404,13 @@ static const struct snd_soc_component_driver dmaengine_pcm_component = {
.pcm_new = dmaengine_pcm_new,
};
static const struct snd_soc_component_driver dmaengine_pcm_component_process = {
.name = SND_DMAENGINE_PCM_DRV_NAME,
.probe_order = SND_SOC_COMP_ORDER_LATE,
.ops = &dmaengine_pcm_process_ops,
.pcm_new = dmaengine_pcm_new,
};
static const char * const dmaengine_pcm_dma_channel_names[] = {
[SNDRV_PCM_STREAM_PLAYBACK] = "tx",
[SNDRV_PCM_STREAM_CAPTURE] = "rx",
@ -453,8 +506,13 @@ int snd_dmaengine_pcm_register(struct device *dev,
if (ret)
goto err_free_pcm;
ret = snd_soc_add_component(dev, &pcm->component,
&dmaengine_pcm_component, NULL, 0);
if (config && config->process)
ret = snd_soc_add_component(dev, &pcm->component,
&dmaengine_pcm_component_process,
NULL, 0);
else
ret = snd_soc_add_component(dev, &pcm->component,
&dmaengine_pcm_component, NULL, 0);
if (ret)
goto err_free_dma;