ASoC: codec: max98373-sdw: refine tdm support

We only use tdm_slots for playback as required by the machine driver.
For the capture the number of channels is fixed to two and the
tdm_slot is irrelevant.

Signed-off-by: Ryan Lee <ryans.lee@maximintegrated.com>
Signed-off-by: Rander Wang <rander.wang@intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>

Author: RanderWang

sound/soc/codecs/max98373-sdw.c

@@ -614,11 +614,16 @@ static int max98373_sdw_dai_hw_params(struct snd_pcm_substream *substream,
 	stream_config.bps = snd_pcm_format_width(params_format(params));
 	stream_config.direction = direction;
 
-	if (max98373->slot) {
+	if (max98373->slot && direction == SDW_DATA_DIR_RX) {
 		stream_config.ch_count = max98373->slot;
 		port_config.ch_mask = max98373->rx_mask;
 	} else {
-		stream_config.ch_count = params_channels(params);
+		/* only IV are supported by capture */
+		if (direction == SDW_DATA_DIR_TX)
+			stream_config.ch_count = 2;
+		else
+			stream_config.ch_count = params_channels(params);
+
 		port_config.ch_mask = GENMASK(stream_config.ch_count - 1, 0);
 	}
 
@@ -774,7 +779,8 @@ static int max98373_sdw_set_tdm_slot(struct snd_soc_dai *dai,
 	struct max98373_priv *max98373 =
 		snd_soc_component_get_drvdata(component);
 
-	if (!tx_mask && !rx_mask && !slots && !slot_width)
+	/* tx_mask is ignored since it's irrelevant for I/V feedback */
+	if (!rx_mask && !slots && !slot_width)
 		max98373->tdm_mode = false;
 	else
 		max98373->tdm_mode = true;