Thread (35 messages) 35 messages, 8 authors, 2013-03-11
STALE4841d

[PATCH 09/12] ASoC: dmaengine_pcm: support use of generic DMA helper

From: Shawn Guo <hidden>
Date: 2013-02-27 15:25:45
Also in: alsa-devel
Subsystem: sound, sound - dmaengine helpers, sound - soc layer / dynamic audio power management (asoc), the rest · Maintainers: Jaroslav Kysela, Takashi Iwai, Lars-Peter Clausen, Liam Girdwood, Mark Brown, Linus Torvalds

With generic DMA device tree binding and helper function
dma_request_slave_channel() in place, dmaengine_pcm should support
that in requesting DMA channel for users that support generic DMA
device tree binding.

Instead of inventing a new API, it defines the parameters needed by
dma_request_slave_channel() into struct snd_dma_channel_params,
interprets filter_data into snd_dma_channel_params, and calls the
helper in case that dmaengine_pcm users pass in a NULL filter_fn.

Then, dmaengine_pcm users can call snd_dmaengine_pcm_open() with NULL
filter_fn and snd_dma_channel_params being filter_data to direct the
API to request DMA channel using generic DMA helper.

Signed-off-by: Shawn Guo <redacted>
Cc: Mark Brown <redacted>
Cc: alsa-devel at alsa-project.org
---
 include/sound/dmaengine_pcm.h |    5 +++++
 sound/soc/soc-dmaengine-pcm.c |   19 +++++++++++++------
 2 files changed, 18 insertions(+), 6 deletions(-)
diff --git a/include/sound/dmaengine_pcm.h b/include/sound/dmaengine_pcm.h
index b877334..6c0f795 100644
--- a/include/sound/dmaengine_pcm.h
+++ b/include/sound/dmaengine_pcm.h
@@ -18,6 +18,11 @@
 #include <sound/pcm.h>
 #include <linux/dmaengine.h>
 
+struct snd_dma_channel_params {
+	struct device *dev;
+	char *name;
+};
+
 /**
  * snd_pcm_substream_to_dma_direction - Get dma_transfer_direction for a PCM
  *   substream
diff --git a/sound/soc/soc-dmaengine-pcm.c b/sound/soc/soc-dmaengine-pcm.c
index 111b7d92..7ef8034 100644
--- a/sound/soc/soc-dmaengine-pcm.c
+++ b/sound/soc/soc-dmaengine-pcm.c
@@ -247,12 +247,19 @@ EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
 static int dmaengine_pcm_request_channel(struct dmaengine_pcm_runtime_data *prtd,
 	dma_filter_fn filter_fn, void *filter_data)
 {
-	dma_cap_mask_t mask;
-
-	dma_cap_zero(mask);
-	dma_cap_set(DMA_SLAVE, mask);
-	dma_cap_set(DMA_CYCLIC, mask);
-	prtd->dma_chan = dma_request_channel(mask, filter_fn, filter_data);
+	if (filter_fn) {
+		dma_cap_mask_t mask;
+
+		dma_cap_zero(mask);
+		dma_cap_set(DMA_SLAVE, mask);
+		dma_cap_set(DMA_CYCLIC, mask);
+		prtd->dma_chan = dma_request_channel(mask, filter_fn,
+						     filter_data);
+	} else {
+		struct snd_dma_channel_params *params = filter_data;
+		prtd->dma_chan = dma_request_slave_channel(params->dev,
+							   params->name);
+	}
 
 	if (!prtd->dma_chan)
 		return -ENXIO;
-- 
1.7.9.5
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help