[alsa-devel] [PATCH v2] ASoC: Intel: bxt: Use refcap device for mono recording

[Yong Zhi]

The refcap capture device supports mono recording only, this patch
adds the channel constraints.

Signed-off-by: Yong Zhi <yong.zhi at intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
---
Changes since v1:
- Remove renaming of "Refcap".
- Add Reviewed-by tag.

 sound/soc/intel/boards/bxt_da7219_max98357a.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/sound/soc/intel/boards/bxt_da7219_max98357a.c b/sound/soc/intel/boards/bxt_da7219_max98357a.c
index be6e4b40bf03..6f052fc8d1e2 100644
--- a/sound/soc/intel/boards/bxt_da7219_max98357a.c
+++ b/sound/soc/intel/boards/bxt_da7219_max98357a.c
@@ -324,8 +324,22 @@ static const struct snd_pcm_hw_constraint_list constraints_16000 = {
 	.list  = rates_16000,
 };
 
+static const unsigned int ch_mono[] = {
+	1,
+};
+
+static const struct snd_pcm_hw_constraint_list constraints_refcap = {
+	.count = ARRAY_SIZE(ch_mono),
+	.list  = ch_mono,
+};
+
 static int broxton_refcap_startup(struct snd_pcm_substream *substream)
 {
+	substream->runtime->hw.channels_max = 1;
+	snd_pcm_hw_constraint_list(substream->runtime, 0,
+				   SNDRV_PCM_HW_PARAM_CHANNELS,
+				   &constraints_refcap);
+
 	return snd_pcm_hw_constraint_list(substream->runtime, 0,
 			SNDRV_PCM_HW_PARAM_RATE,
 			&constraints_16000);
-- 
2.7.4