From: Shengjiu Wang <shengjiu.wang@nxp.com>
Date: Wed, 25 Feb 2026 10:09:07 +0000 (+0800)
Subject: ASoC: cs42xx8: add error checks for constraints in TDM mode
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=da37bfe76b5b4ccc01ed8132215098e20d78e5f3;p=thirdparty%2Flinux.git

ASoC: cs42xx8: add error checks for constraints in TDM mode

In the TDM format the ADC and DAC serial ports will only operate as a
slave, the sysclk should not be less than 256FS and Quad-Speed Mode (100
to 200 kHz sample rates) is not supported by ADC. So add error checks
for these constraints.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Link: https://patch.msgid.link/20260225100907.686470-1-shengjiu.wang@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>
---

diff --git a/sound/soc/codecs/cs42xx8.c b/sound/soc/codecs/cs42xx8.c
index f6b8fe7d53e2c..12fe9b3e2525e 100644
--- a/sound/soc/codecs/cs42xx8.c
+++ b/sound/soc/codecs/cs42xx8.c
@@ -40,6 +40,7 @@ struct cs42xx8_priv {
 	struct clk *clk;
 
 	bool slave_mode;
+	bool is_tdm_mode;
 	unsigned long sysclk;
 	u32 tx_channels;
 	struct gpio_desc *gpiod_reset;
@@ -214,6 +215,8 @@ static int cs42xx8_set_dai_fmt(struct snd_soc_dai *codec_dai,
 	struct cs42xx8_priv *cs42xx8 = snd_soc_component_get_drvdata(component);
 	u32 val;
 
+	cs42xx8->is_tdm_mode = false;
+
 	/* Set DAI format */
 	switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {
 	case SND_SOC_DAIFMT_LEFT_J:
@@ -227,6 +230,7 @@ static int cs42xx8_set_dai_fmt(struct snd_soc_dai *codec_dai,
 		break;
 	case SND_SOC_DAIFMT_DSP_A:
 		val = CS42XX8_INTF_DAC_DIF_TDM | CS42XX8_INTF_ADC_DIF_TDM;
+		cs42xx8->is_tdm_mode = true;
 		break;
 	default:
 		dev_err(component->dev, "unsupported dai format\n");
@@ -250,6 +254,11 @@ static int cs42xx8_set_dai_fmt(struct snd_soc_dai *codec_dai,
 		return -EINVAL;
 	}
 
+	if (cs42xx8->is_tdm_mode && !cs42xx8->slave_mode) {
+		dev_err(component->dev, "TDM mode is supported only in slave mode\n");
+		return -EINVAL;
+	}
+
 	return 0;
 }
 
@@ -332,6 +341,19 @@ static int cs42xx8_hw_params(struct snd_pcm_substream *substream,
 
 	cs42xx8->rate[tx] = params_rate(params);
 
+	if (cs42xx8->is_tdm_mode) {
+		if (cs42xx8->sysclk < 256 * cs42xx8->rate[tx]) {
+			dev_err(component->dev, "Unsupported sysclk in TDM mode\n");
+			return -EINVAL;
+		}
+
+		if (!tx && cs42xx8->rate[tx] > 100000) {
+			dev_err(component->dev,
+				"ADC does not support Quad-Speed Mode in TDM mode\n");
+			return -EINVAL;
+		}
+	}
+
 	mask = CS42XX8_FUNCMOD_MFREQ_MASK;
 	val = cs42xx8_ratios[i].mfreq;