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authorStephen Warren <swarren@nvidia.com>2013-12-03 14:26:34 -0700
committerMark Brown <broonie@linaro.org>2013-12-09 18:45:01 +0000
commit194c7dea00c68c1b1f8ff26304fa937a006f66dd (patch)
tree5490b3298d3db2ae76ba2dbdc0ca8c7ffaefd3f4 /sound
parenta715d01e9c8177634bd7c22e67c9088282744569 (diff)
downloadblackbird-op-linux-194c7dea00c68c1b1f8ff26304fa937a006f66dd.tar.gz
blackbird-op-linux-194c7dea00c68c1b1f8ff26304fa937a006f66dd.zip
ASoC: dmaengine: add custom DMA config to snd_dmaengine_pcm_config
Add fields to struct snd_dmaengine_pcm_config to allow custom: - DMA channel names. This is useful when the default "tx" and "rx" channel names don't apply, for example if a HW module supports multiple channels, each having different DMA channel names. This is the case with the FIFOs in Tegra's AHUB. This new facility can replace SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME. - DMA device This allows requesting DMA channels for a device other than the device which is registering the "PCM" driver. This is quite unusual, but is currently useful on Tegra. In much HW, and in Tegra20, each DAI HW module contains its own FIFOs which DMA writes to. However, in Tegra30, the DMA FIFOs were split out AHUB HW module, which then routes the data through a cross-bar, and into the DAI HW modules. However, the current ASoC driver structure does not expose this detail, and acts as if the FIFOs are still part of the DAI HW modules. Consequently, the "PCM" driver is registered with the DAI HW module, yet the DMA channels must be looked up in the AHUB HW module's device tree node. This new config field allows that to happen. Eventually, the Tegra drivers will be reworked to fully expose the AHUB, and this config field can be removed. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Mark Brown <broonie@linaro.org>
Diffstat (limited to 'sound')
-rw-r--r--sound/soc/soc-generic-dmaengine-pcm.c18
1 files changed, 16 insertions, 2 deletions
diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c
index 1cb3494cf278..5b70c556fba3 100644
--- a/sound/soc/soc-generic-dmaengine-pcm.c
+++ b/sound/soc/soc-generic-dmaengine-pcm.c
@@ -288,7 +288,7 @@ static const char * const dmaengine_pcm_dma_channel_names[] = {
};
static void dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
- struct device *dev)
+ struct device *dev, const struct snd_dmaengine_pcm_config *config)
{
unsigned int i;
const char *name;
@@ -298,12 +298,26 @@ static void dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
!dev->of_node)
return;
+ if (config->dma_dev) {
+ /*
+ * If this warning is seen, it probably means that your Linux
+ * device structure does not match your HW device structure.
+ * It would be best to refactor the Linux device structure to
+ * correctly match the HW structure.
+ */
+ dev_warn(dev, "DMA channels sourced from device %s",
+ dev_name(config->dma_dev));
+ dev = config->dma_dev;
+ }
+
for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE;
i++) {
if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
name = "rx-tx";
else
name = dmaengine_pcm_dma_channel_names[i];
+ if (config->chan_names[i])
+ name = config->chan_names[i];
pcm->chan[i] = dma_request_slave_channel(dev, name);
if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
break;
@@ -346,7 +360,7 @@ int snd_dmaengine_pcm_register(struct device *dev,
pcm->config = config;
pcm->flags = flags;
- dmaengine_pcm_request_chan_of(pcm, dev);
+ dmaengine_pcm_request_chan_of(pcm, dev, config);
if (flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
ret = snd_soc_add_platform(dev, &pcm->platform,
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