[PATCH v2] ASoC: mediatek: mt8192-mt6359: add format constraints for RT5682

[Tzung-Bi Shih]

MT8192 determines the I2S clock rates according to the sampling rates.

There is only 1 set of I2S in between MT8192 and RT5682.  If playing and
capturing via RT5682 in different sampling rates, the I2S data will be
corrupted.

Adds format constraints to the corresponding DAI links to make sure the
sampling rates are symmetric.

Fixes: 18b13ff23fab ("ASoC: mediatek: mt8192: add machine driver with mt6359, rt1015 and rt5682")
Signed-off-by: Tzung-Bi Shih <tzungbi at google.com>
---
Changes from previous version:
- Separated from the series [1] per [2].
- Updated commit message for more details.

[1]: https://patchwork.kernel.org/project/alsa-devel/list/?series=419769
[2]: https://patchwork.kernel.org/project/alsa-devel/patch/20210122100742.3699128-2-tzungbi@google.com/#23919795

 .../mt8192/mt8192-mt6359-rt1015-rt5682.c      | 49 +++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/sound/soc/mediatek/mt8192/mt8192-mt6359-rt1015-rt5682.c b/sound/soc/mediatek/mt8192/mt8192-mt6359-rt1015-rt5682.c
index cc0fc72305d2..c368236d8a3a 100644
--- a/sound/soc/mediatek/mt8192/mt8192-mt6359-rt1015-rt5682.c
+++ b/sound/soc/mediatek/mt8192/mt8192-mt6359-rt1015-rt5682.c
@@ -410,6 +410,53 @@ static const struct snd_soc_ops mt8192_mt6359_rt1015_rt5682_capture1_ops = {
 	.startup = mt8192_mt6359_rt1015_rt5682_cap1_startup,
 };
 
+static int
+mt8192_mt6359_rt5682_startup(struct snd_pcm_substream *substream)
+{
+	static const unsigned int channels[] = {
+		1, 2
+	};
+	static const struct snd_pcm_hw_constraint_list constraints_channels = {
+		.count = ARRAY_SIZE(channels),
+		.list = channels,
+		.mask = 0,
+	};
+	static const unsigned int rates[] = {
+		48000
+	};
+	static const struct snd_pcm_hw_constraint_list constraints_rates = {
+		.count = ARRAY_SIZE(rates),
+		.list  = rates,
+		.mask = 0,
+	};
+
+	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int ret;
+
+	ret = snd_pcm_hw_constraint_list(runtime, 0,
+					 SNDRV_PCM_HW_PARAM_CHANNELS,
+					 &constraints_channels);
+	if (ret < 0) {
+		dev_err(rtd->dev, "hw_constraint_list channels failed\n");
+		return ret;
+	}
+
+	ret = snd_pcm_hw_constraint_list(runtime, 0,
+					 SNDRV_PCM_HW_PARAM_RATE,
+					 &constraints_rates);
+	if (ret < 0) {
+		dev_err(rtd->dev, "hw_constraint_list rate failed\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct snd_soc_ops mt8192_mt6359_rt5682_ops = {
+	.startup = mt8192_mt6359_rt5682_startup,
+};
+
 /* FE */
 SND_SOC_DAILINK_DEFS(playback1,
 		     DAILINK_COMP_ARRAY(COMP_CPU("DL1")),
@@ -657,6 +704,7 @@ static struct snd_soc_dai_link mt8192_mt6359_dai_links[] = {
 			    SND_SOC_DPCM_TRIGGER_PRE},
 		.dynamic = 1,
 		.dpcm_playback = 1,
+		.ops = &mt8192_mt6359_rt5682_ops,
 		SND_SOC_DAILINK_REG(playback3),
 	},
 	{
@@ -730,6 +778,7 @@ static struct snd_soc_dai_link mt8192_mt6359_dai_links[] = {
 			    SND_SOC_DPCM_TRIGGER_PRE},
 		.dynamic = 1,
 		.dpcm_capture = 1,
+		.ops = &mt8192_mt6359_rt5682_ops,
 		SND_SOC_DAILINK_REG(capture2),
 	},
 	{
-- 
2.30.0.280.ga3ce27912f-goog