From b0a6cd7d6417ed337c041aec967c234266ce2ebf Mon Sep 17 00:00:00 2001
From: Mark Brown <broonie@opensource.wolfsonmicro.com>
Date: Mon, 16 Jan 2012 18:38:51 +0000
Subject: [PATCH] --- yaml --- r: 293196 b: refs/heads/master c:
 58ba9b25454fe9b6ded804f69cb7ed4500b685fc h: refs/heads/master v: v3

---
 [refs]                    |  2 +-
 trunk/include/sound/soc.h |  1 +
 trunk/sound/soc/soc-pcm.c | 36 ++++++++++++++++++++++++++++++++++++
 3 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 2ddbbff490a9..576abc8e8065 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 5f52ee48751e63ed555b56a82db446745f60bc82
+refs/heads/master: 58ba9b25454fe9b6ded804f69cb7ed4500b685fc
diff --git a/trunk/include/sound/soc.h b/trunk/include/sound/soc.h
index 0992dff55959..55381fca6e0d 100644
--- a/trunk/include/sound/soc.h
+++ b/trunk/include/sound/soc.h
@@ -505,6 +505,7 @@ struct snd_soc_pcm_stream {
 	unsigned int rate_max;		/* max rate */
 	unsigned int channels_min;	/* min channels */
 	unsigned int channels_max;	/* max channels */
+	unsigned int sig_bits;		/* number of bits of content */
 };
 
 /* SoC audio ops */
diff --git a/trunk/sound/soc/soc-pcm.c b/trunk/sound/soc/soc-pcm.c
index cdc860a5ff37..8bb17937d59a 100644
--- a/trunk/sound/soc/soc-pcm.c
+++ b/trunk/sound/soc/soc-pcm.c
@@ -62,6 +62,39 @@ static int soc_pcm_apply_symmetry(struct snd_pcm_substream *substream,
 	return 0;
 }
 
+/*
+ * List of sample sizes that might go over the bus for parameter
+ * application.  There ought to be a wildcard sample size for things
+ * like the DAC/ADC resolution to use but there isn't right now.
+ */
+static int sample_sizes[] = {
+	8, 16, 24, 32,
+};
+
+static void soc_pcm_apply_msb(struct snd_pcm_substream *substream,
+			      struct snd_soc_dai *dai)
+{
+	int ret, i, bits;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		bits = dai->driver->playback.sig_bits;
+	else
+		bits = dai->driver->capture.sig_bits;
+
+	if (!bits)
+		return;
+
+	for (i = 0; i < ARRAY_SIZE(sample_sizes); i++) {
+		ret = snd_pcm_hw_constraint_msbits(substream->runtime,
+						   0, sample_sizes[i],
+						   bits);
+		if (ret != 0)
+			dev_warn(dai->dev,
+				 "Failed to set MSB %d/%d: %d\n",
+				 bits, sample_sizes[i], ret);
+	}
+}
+
 /*
  * Called by ALSA when a PCM substream is opened, the runtime->hw record is
  * then initialized and any private data can be allocated. This also calls
@@ -187,6 +220,9 @@ static int soc_pcm_open(struct snd_pcm_substream *substream)
 		goto config_err;
 	}
 
+	soc_pcm_apply_msb(substream, codec_dai);
+	soc_pcm_apply_msb(substream, cpu_dai);
+
 	/* Symmetry only applies if we've already got an active stream. */
 	if (cpu_dai->active) {
 		ret = soc_pcm_apply_symmetry(substream, cpu_dai);