Merge series "add channel constraint for BDW machine drivers" from Brent Lu <brent.lu@intel.com>:

The machine driver bdw-rt5650 (for Google buddy) supports 2 or 4-channel
recording while other two drivers support only 2-channel recording. HW
constraints are implemented to reflect the hardware limitation on BDW
platform.

Changes since v1:
- Change the patch title.
- Remove the DUAL_CHANNEL and QUAD_CHANNEL macros which are too obvious.
- Follow the naming convertion, using 'bdw_rt5650_' and 'bdw_rt5677_' to
  name startup functions.
- Refine the comments in startup functions.
- Redesign the bdw_rt5650_fe_startup() function for readability.
- Add an assignment to initialize runtime->hw.channels_max variable.

Brent Lu (3):
  ASoC: bdw-rt5677: add channel constraint
  ASoC: bdw-rt5650: add channel constraint
  ASoC: broadwell: add channel constraint

 sound/soc/intel/boards/bdw-rt5650.c | 29 +++++++++++++++++++++++++++++
 sound/soc/intel/boards/bdw-rt5677.c | 26 ++++++++++++++++++++++++++
 sound/soc/intel/boards/broadwell.c  | 26 ++++++++++++++++++++++++++
 3 files changed, 81 insertions(+)

--
2.7.4

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

sound/soc/intel/boards/bdw-rt5677.c

@@ -222,6 +222,31 @@ static int bdw_rt5677_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 bdw_rt5677_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 bdw_rt5677_fe_ops = {
+	.startup = bdw_rt5677_fe_startup,
+};
+
 static int bdw_rt5677_init(struct snd_soc_pcm_runtime *rtd)
 {
 	struct bdw_rt5677_priv *bdw_rt5677 =
@@ -321,6 +346,7 @@ static struct snd_soc_dai_link bdw_rt5677_dais[] = {
 		},
 		.dpcm_capture = 1,
 		.dpcm_playback = 1,
+		.ops = &bdw_rt5677_fe_ops,
 		SND_SOC_DAILINK_REG(fe, dummy, platform),
 	},
 

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),