[alsa-devel] [PATCH 3/3] ASoC: soc-compress: Split copy into seperate read and write callbacks

[Charles Keepax]

The compress API for non-memory mapped DSPs shares a copy callback for
both read and write, however the file operation of write passes a const
buffer. Thus we can't maintain const correctness for the copy callback
and support both read and write.

This patch seperates the read and write callbacks in the ASoC compressed
API.

Signed-off-by: Charles Keepax <ckeepax at opensource.wolfsonmicro.com>
---
 sound/soc/soc-compress.c |   34 +++++++++++++++++++++++++++-------
 1 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/sound/soc/soc-compress.c b/sound/soc/soc-compress.c
index f9b2197..0148d82 100644
--- a/sound/soc/soc-compress.c
+++ b/sound/soc/soc-compress.c
@@ -306,8 +306,8 @@ static int soc_compr_pointer(struct snd_compr_stream *cstream,
 	return 0;
 }
 
-static int soc_compr_copy(struct snd_compr_stream *cstream,
-			  const char __user *buf, size_t count)
+static int soc_compr_write(struct snd_compr_stream *cstream,
+			   const char __user *buf, size_t count)
 {
 	struct snd_soc_pcm_runtime *rtd = cstream->private_data;
 	struct snd_soc_platform *platform = rtd->platform;
@@ -315,8 +315,24 @@ static int soc_compr_copy(struct snd_compr_stream *cstream,
 
 	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
 
-	if (platform->driver->compr_ops && platform->driver->compr_ops->copy)
-		ret = platform->driver->compr_ops->copy(cstream, buf, count);
+	if (platform->driver->compr_ops && platform->driver->compr_ops->write)
+		ret = platform->driver->compr_ops->write(cstream, buf, count);
+
+	mutex_unlock(&rtd->pcm_mutex);
+	return ret;
+}
+
+static int soc_compr_read(struct snd_compr_stream *cstream,
+			  char __user *buf, size_t count)
+{
+	struct snd_soc_pcm_runtime *rtd = cstream->private_data;
+	struct snd_soc_platform *platform = rtd->platform;
+	int ret = 0;
+
+	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
+
+	if (platform->driver->compr_ops && platform->driver->compr_ops->read)
+		ret = platform->driver->compr_ops->read(cstream, buf, count);
 
 	mutex_unlock(&rtd->pcm_mutex);
 	return ret;
@@ -392,9 +408,13 @@ int soc_new_compress(struct snd_soc_pcm_runtime *rtd, int num)
 	}
 	memcpy(compr->ops, &soc_compr_ops, sizeof(soc_compr_ops));
 
-	/* Add copy callback for not memory mapped DSPs */
-	if (platform->driver->compr_ops && platform->driver->compr_ops->copy)
-		compr->ops->copy = soc_compr_copy;
+	/* Add write/read callback for not memory mapped DSPs */
+	if (platform->driver->compr_ops) {
+		if (platform->driver->compr_ops->write)
+			compr->ops->write = soc_compr_write;
+		if (platform->driver->compr_ops->read)
+			compr->ops->read = soc_compr_read;
+	}
 
 	mutex_init(&compr->lock);
 	ret = snd_compress_new(rtd->card->snd_card, num, direction, compr);
-- 
1.7.2.5