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@xxxxxx>
---
include/sound/dmaengine_pcm.h | 3 ++
sound/soc/soc-generic-dmaengine-pcm.c | 62 +++++++++++++++++++++++++++++++++--
2 files changed, 63 insertions(+), 2 deletions(-)
diff --git a/include/sound/dmaengine_pcm.h b/include/sound/dmaengine_pcm.h
index 8a5a840..47ef486 100644
--- a/include/sound/dmaengine_pcm.h
+++ b/include/sound/dmaengine_pcm.h
@@ -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];
diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c
index c07d5c7..1c1d838 100644
--- a/sound/soc/soc-generic-dmaengine-pcm.c
+++ b/sound/soc/soc-generic-dmaengine-pcm.c
@@ -340,6 +340,41 @@ 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,
@@ -350,6 +385,17 @@ static snd_pcm_uframes_t dmaengine_pcm_pointer(
.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,
@@ -357,6 +403,13 @@ static snd_pcm_uframes_t dmaengine_pcm_pointer(
.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",
@@ -449,8 +502,13 @@ int snd_dmaengine_pcm_register(struct device *dev,
if (ret)
goto err_free_dma;
- 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;
--
1.9.1
--
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