ASoC: codecs: max98090: Allow dsp_a mode

TDM mode for max98090 is dsp_a compatible with such limitations:
1) Up to four timeslots supported.
2) Only 16 bits timeslots supported.
3) Only 2 active timeslots (L/R) supported.

We want to setup TDM mode only when dsp_a mode is selected. So move
M98090_REG_TDM_FORMAT/M98090_REG_TDM_CONTROL registers setup from
max98090_set_tdm_slot() to the max98090_dai_set_fmt(). Also extend
max98090_set_tdm_slot() with all TDM limitations check.

Signed-off-by: Maxim Kochetkov <fido_max@inbox.ru>
Link: https://lore.kernel.org/r/Message-Id: <20230622142038.63388-1-fido_max@inbox.ru>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/max98090.c

@@ -1581,7 +1581,7 @@ static int max98090_dai_set_fmt(struct snd_soc_dai *codec_dai,
 	struct snd_soc_component *component = codec_dai->component;
 	struct max98090_priv *max98090 = snd_soc_component_get_drvdata(component);
 	struct max98090_cdata *cdata;
-	u8 regval;
+	u8 regval, tdm_regval;
 
 	max98090->dai_fmt = fmt;
 	cdata = &max98090->dai[0];
@@ -1590,6 +1590,7 @@ static int max98090_dai_set_fmt(struct snd_soc_dai *codec_dai,
 		cdata->fmt = fmt;
 
 		regval = 0;
+		tdm_regval = 0;
 		switch (fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
 		case SND_SOC_DAIFMT_CBC_CFC:
 			/* Set to consumer mode PLL - MAS mode off */
@@ -1635,7 +1636,8 @@ static int max98090_dai_set_fmt(struct snd_soc_dai *codec_dai,
 			regval |= M98090_RJ_MASK;
 			break;
 		case SND_SOC_DAIFMT_DSP_A:
-			/* Not supported mode */
+			tdm_regval |= M98090_TDM_MASK;
+			break;
 		default:
 			dev_err(component->dev, "DAI format unsupported");
 			return -EINVAL;
@@ -1664,11 +1666,20 @@ static int max98090_dai_set_fmt(struct snd_soc_dai *codec_dai,
 		 * seen for the case of TDM mode. The remaining cases have
 		 * normal logic.
 		 */
-		if (max98090->tdm_slots > 1)
+		if (tdm_regval)
 			regval ^= M98090_BCI_MASK;
 
 		snd_soc_component_write(component,
 			M98090_REG_INTERFACE_FORMAT, regval);
+
+		regval = 0;
+		if (tdm_regval)
+			regval = max98090->tdm_lslot << M98090_TDM_SLOTL_SHIFT |
+				 max98090->tdm_rslot << M98090_TDM_SLOTR_SHIFT |
+				 0 << M98090_TDM_SLOTDLY_SHIFT;
+
+		snd_soc_component_write(component, M98090_REG_TDM_FORMAT, regval);
+		snd_soc_component_write(component, M98090_REG_TDM_CONTROL, tdm_regval);
 	}
 
 	return 0;
@@ -1679,33 +1690,22 @@ static int max98090_set_tdm_slot(struct snd_soc_dai *codec_dai,
 {
 	struct snd_soc_component *component = codec_dai->component;
 	struct max98090_priv *max98090 = snd_soc_component_get_drvdata(component);
-	struct max98090_cdata *cdata;
-	cdata = &max98090->dai[0];
 
 	if (slots < 0 || slots > 4)
 		return -EINVAL;
 
+	if (slot_width != 16)
+		return -EINVAL;
+
+	if (rx_mask != tx_mask)
+		return -EINVAL;
+
+	if (!rx_mask)
+		return -EINVAL;
+
 	max98090->tdm_slots = slots;
-	max98090->tdm_width = slot_width;
+	max98090->tdm_lslot = ffs(rx_mask) - 1;
-
+	max98090->tdm_rslot = fls(rx_mask) - 1;
-	if (max98090->tdm_slots > 1) {
-		/* SLOTL SLOTR SLOTDLY */
-		snd_soc_component_write(component, M98090_REG_TDM_FORMAT,
-			0 << M98090_TDM_SLOTL_SHIFT |
-			1 << M98090_TDM_SLOTR_SHIFT |
-			0 << M98090_TDM_SLOTDLY_SHIFT);
-
-		/* FSW TDM */
-		snd_soc_component_update_bits(component, M98090_REG_TDM_CONTROL,
-			M98090_TDM_MASK,
-			M98090_TDM_MASK);
-	}
-
-	/*
-	 * Normally advisable to set TDM first, but this permits either order
-	 */
-	cdata->fmt = 0;
-	max98090_dai_set_fmt(codec_dai, max98090->dai_fmt);
 
 	return 0;
 }
@@ -2408,6 +2408,9 @@ static int max98090_probe(struct snd_soc_component *component)
 	max98090->pa1en = 0;
 	max98090->pa2en = 0;
 
+	max98090->tdm_lslot = 0;
+	max98090->tdm_rslot = 1;
+
 	ret = snd_soc_component_read(component, M98090_REG_REVISION_ID);
 	if (ret < 0) {
 		dev_err(component->dev, "Failed to read device revision: %d\n",

sound/soc/codecs/max98090.h

@@ -1533,7 +1533,8 @@ struct max98090_priv {
 	struct snd_soc_jack *jack;
 	unsigned int dai_fmt;
 	int tdm_slots;
-	int tdm_width;
+	int tdm_lslot;
+	int tdm_rslot;
 	u8 lin_state;
 	unsigned int pa1en;
 	unsigned int pa2en;