+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,
+};
+