ASoC: bdw-rt5650: add channel constraint

BDW boards using this machine driver supports only 2 or 4-channel capture.
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/1588007614-25061-3-git-send-email-brent.lu@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/intel/boards/bdw-rt5650.c b/sound/soc/intel/boards/bdw-rt5650.c
index af2f502..a97e912 100644 (file)
--- a/sound/soc/intel/boards/bdw-rt5650.c
+++ b/sound/soc/intel/boards/bdw-rt5650.c
@@ -162,6 +162,34 @@ static int bdw_rt5650_rtd_init(struct snd_soc_pcm_runtime *rtd)
 }
 #endif
 
+static const unsigned int channels[] = {
+       2, 4,
+};
+
+static const struct snd_pcm_hw_constraint_list constraints_channels = {
+       .count = ARRAY_SIZE(channels),
+       .list = channels,
+       .mask = 0,
+};
+
+static int bdw_rt5650_fe_startup(struct snd_pcm_substream *substream)
+{
+       struct snd_pcm_runtime *runtime = substream->runtime;
+
+       /* Board supports stereo and quad configurations for capture */
+       if (substream->stream != SNDRV_PCM_STREAM_CAPTURE)
+               return 0;
+
+       runtime->hw.channels_max = 4;
+       return snd_pcm_hw_constraint_list(runtime, 0,
+                                         SNDRV_PCM_HW_PARAM_CHANNELS,
+                                         &constraints_channels);
+}
+
+static const struct snd_soc_ops bdw_rt5650_fe_ops = {
+       .startup = bdw_rt5650_fe_startup,
+};
+
 static int bdw_rt5650_init(struct snd_soc_pcm_runtime *rtd)
 {
        struct bdw_rt5650_priv *bdw_rt5650 =
@@ -234,6 +262,7 @@ static struct snd_soc_dai_link bdw_rt5650_dais[] = {
                .name = "System PCM",
                .stream_name = "System Playback",
                .dynamic = 1,
+               .ops = &bdw_rt5650_fe_ops,
 #if !IS_ENABLED(CONFIG_SND_SOC_SOF_BROADWELL)
                .init = bdw_rt5650_rtd_init,
 #endif