ASoC: Intel: Skylake: Add dai link for DMIC capture

Since in Skylake we support another DAI for DMIC quad capture,
add a dailink for this as well. Also specify constrains for DMIC
FE devices and fixup for DMIC BEs

Signed-off-by: Dharageswari.R <dharageswari.r@intel.com>
Signed-off-by: Jeeja KP <jeeja.kp@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/boards/skl_rt286.c

@@ -190,6 +190,42 @@ static struct snd_soc_ops skylake_rt286_ops = {
 	.hw_params = skylake_rt286_hw_params,
 };
 
+static int skylake_dmic_fixup(struct snd_soc_pcm_runtime *rtd,
+				struct snd_pcm_hw_params *params)
+{
+	struct snd_interval *channels = hw_param_interval(params,
+						SNDRV_PCM_HW_PARAM_CHANNELS);
+	channels->min = channels->max = 4;
+
+	return 0;
+}
+
+static unsigned int channels_dmic[] = {
+	2, 4,
+};
+
+static struct snd_pcm_hw_constraint_list constraints_dmic_channels = {
+	.count = ARRAY_SIZE(channels_dmic),
+	.list = channels_dmic,
+	.mask = 0,
+};
+
+static int skylake_dmic_startup(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	runtime->hw.channels_max = 4;
+	snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
+					   &constraints_dmic_channels);
+
+	return snd_pcm_hw_constraint_list(substream->runtime, 0,
+			SNDRV_PCM_HW_PARAM_RATE, &constraints_rates);
+}
+
+static struct snd_soc_ops skylake_dmic_ops = {
+	.startup = skylake_dmic_startup,
+};
+
 /* skylake digital audio interface glue - connects codec <--> CPU */
 static struct snd_soc_dai_link skylake_rt286_dais[] = {
 	/* Front End DAI links */
@@ -238,6 +274,20 @@ static struct snd_soc_dai_link skylake_rt286_dais[] = {
 		.nonatomic = 1,
 		.dynamic = 1,
 	},
+	{
+		.name = "Skl Audio DMIC cap",
+		.stream_name = "dmiccap",
+		.cpu_dai_name = "DMIC Pin",
+		.codec_name = "snd-soc-dummy",
+		.codec_dai_name = "snd-soc-dummy-dai",
+		.platform_name = "0000:00:1f.3",
+		.init = NULL,
+		.dpcm_capture = 1,
+		.ignore_suspend = 1,
+		.nonatomic = 1,
+		.dynamic = 1,
+		.ops = &skylake_dmic_ops,
+	},
 
 	/* Back End DAI links */
 	{
@@ -267,6 +317,7 @@ static struct snd_soc_dai_link skylake_rt286_dais[] = {
 		.codec_name = "dmic-codec",
 		.codec_dai_name = "dmic-hifi",
 		.platform_name = "0000:00:1f.3",
+		.be_hw_params_fixup = skylake_dmic_fixup,
 		.ignore_suspend = 1,
 		.dpcm_capture = 1,
 		.no_pcm = 1,