ASoC: fsl: fsl_qmc_audio: Ensure audio channels are ordered in TDM bus

To reduce complexity of interrupt handling in following patch, ensure
audio channels are configured in the same order as timeslots on the
TDM bus. If we need a given ordering of audio sources in the audio
frame, it is possible to re-order codecs on the TDM bus, no need to
mix up timeslots in channels.

Acked-by: Herve Codina <herve.codina@bootlin.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://patch.msgid.link/4ff40afdf3d032b05dd4af6c0f777d4d4b445a76.1758209158.git.christophe.leroy@csgroup.eu
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: chleroy

sound/soc/fsl/fsl_qmc_audio.c

@@ -791,12 +791,17 @@ static int qmc_audio_dai_parse(struct qmc_audio *qmc_audio, struct device_node *
 			       struct qmc_dai *qmc_dai,
 			       struct snd_soc_dai_driver *qmc_soc_dai_driver)
 {
+	struct qmc_chan_ts_info ts_info;
 	struct qmc_chan_info info;
 	unsigned long rx_fs_rate;
 	unsigned long tx_fs_rate;
+	int prev_last_rx_ts = 0;
+	int prev_last_tx_ts = 0;
 	unsigned int nb_tx_ts;
 	unsigned int nb_rx_ts;
 	unsigned int i;
+	int last_rx_ts;
+	int last_tx_ts;
 	int count;
 	u32 val;
 	int ret;
@@ -879,6 +884,30 @@ static int qmc_audio_dai_parse(struct qmc_audio *qmc_audio, struct device_node *
 				return -EINVAL;
 			}
 		}
+
+		ret = qmc_chan_get_ts_info(qmc_dai->chans[i].qmc_chan, &ts_info);
+		if (ret) {
+			dev_err(qmc_audio->dev, "dai %d get QMC %d channel TS info failed %d\n",
+				qmc_dai->id, i, ret);
+			return ret;
+		}
+
+		last_rx_ts = fls64(ts_info.rx_ts_mask);
+		last_tx_ts = fls64(ts_info.tx_ts_mask);
+
+		if (prev_last_rx_ts > last_rx_ts) {
+			dev_err(qmc_audio->dev, "dai %d QMC chan %d unordered channels (RX timeslot %d before %d)\n",
+				qmc_dai->id, i, prev_last_rx_ts, last_rx_ts);
+			return -EINVAL;
+		}
+		if (prev_last_tx_ts > last_tx_ts) {
+			dev_err(qmc_audio->dev, "dai %d QMC chan %d unordered channels (TX timeslot %d before %d)\n",
+				qmc_dai->id, i, prev_last_tx_ts, last_tx_ts);
+			return -EINVAL;
+		}
+
+		prev_last_rx_ts = last_rx_ts;
+		prev_last_tx_ts = last_tx_ts;
 	}
 
 	qmc_dai->nb_chans_avail = count;