ASoC: broadwell: add channel constraint

BDW boards using this machine driver supports only stereo capture and
playback. Implement a constraint to enforce it.

Signed-off-by: Brent Lu <brent.lu@intel.com>
Acked-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/1588007614-25061-4-git-send-email-brent.lu@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/intel/boards/broadwell.c b/sound/soc/intel/boards/broadwell.c
index f9a8336..07b2cfd 100644 (file)
--- a/sound/soc/intel/boards/broadwell.c
+++ b/sound/soc/intel/boards/broadwell.c
@@ -143,6 +143,31 @@ static int broadwell_rtd_init(struct snd_soc_pcm_runtime *rtd)
 }
 #endif
 
+static const unsigned int channels[] = {
+       2,
+};
+
+static const struct snd_pcm_hw_constraint_list constraints_channels = {
+       .count = ARRAY_SIZE(channels),
+       .list = channels,
+       .mask = 0,
+};
+
+static int broadwell_fe_startup(struct snd_pcm_substream *substream)
+{
+       struct snd_pcm_runtime *runtime = substream->runtime;
+
+       /* Board supports stereo configuration only */
+       runtime->hw.channels_max = 2;
+       return snd_pcm_hw_constraint_list(runtime, 0,
+                                         SNDRV_PCM_HW_PARAM_CHANNELS,
+                                         &constraints_channels);
+}
+
+static const struct snd_soc_ops broadwell_fe_ops = {
+       .startup = broadwell_fe_startup,
+};
+
 SND_SOC_DAILINK_DEF(system,
        DAILINK_COMP_ARRAY(COMP_CPU("System Pin")));
 
@@ -180,6 +205,7 @@ static struct snd_soc_dai_link broadwell_rt286_dais[] = {
                .init = broadwell_rtd_init,
 #endif
                .trigger = {SND_SOC_DPCM_TRIGGER_POST, SND_SOC_DPCM_TRIGGER_POST},
+               .ops = &broadwell_fe_ops,
                .dpcm_playback = 1,
                .dpcm_capture = 1,
                SND_SOC_DAILINK_REG(system, dummy, platform),