[alsa-devel] [PATCH v2] ASoC: Intel: kbl_rt5663_rt5514_max98927: Add dmic format constraint

[Yu-Hsuan Hsu]

On KBL platform, the microphone is attached to external codec(rt5514)
instead of PCH. However, TDM slot between PCH and codec is 16 bits only.
In order to avoid setting wrong format, we should add a constraint to
force to use 16 bits format forever.

Signed-off-by: Yu-Hsuan Hsu <yuhsuan at chromium.org>
---
I have updated the commit message. Please see whether it is clear
enough. Thanks.
 sound/soc/intel/boards/kbl_rt5663_rt5514_max98927.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sound/soc/intel/boards/kbl_rt5663_rt5514_max98927.c b/sound/soc/intel/boards/kbl_rt5663_rt5514_max98927.c
index 74dda8784f1a01..67b276a65a8d2d 100644
--- a/sound/soc/intel/boards/kbl_rt5663_rt5514_max98927.c
+++ b/sound/soc/intel/boards/kbl_rt5663_rt5514_max98927.c
@@ -400,6 +400,9 @@ static int kabylake_dmic_startup(struct snd_pcm_substream *substream)
 	snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
 			dmic_constraints);
 
+	runtime->hw.formats = SNDRV_PCM_FMTBIT_S16_LE;
+	snd_pcm_hw_constraint_msbits(runtime, 0, 16, 16);
+
 	return snd_pcm_hw_constraint_list(substream->runtime, 0,
 			SNDRV_PCM_HW_PARAM_RATE, &constraints_rates);
 }
-- 
2.23.0.351.gc4317032e6-goog