ASoC: generic-dmaengine-pcm: Add support for half-duplex
Some platforms which are half-duplex share the same DMA channel between the
playback and capture stream. Add support for this to the generic dmaengine PCM
driver.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/include/sound/dmaengine_pcm.h b/include/sound/dmaengine_pcm.h
index b1d1150..f11c35c 100644
--- a/include/sound/dmaengine_pcm.h
+++ b/include/sound/dmaengine_pcm.h
@@ -91,6 +91,11 @@
* bytes that are still left to transfer.
*/
#define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(2)
+/*
+ * The PCM is half duplex and the DMA channel is shared between capture and
+ * playback.
+ */
+#define SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX BIT(3)
/**
* struct snd_dmaengine_pcm_config - Configuration data for dmaengine based PCM