[PATCH v2 2/4] ASoc: fsl: fsl_qmc_audio: Ensure audio channels are ordered in TDM bus

[Christophe Leroy]

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.

Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
---
v2: New
---
 sound/soc/fsl/fsl_qmc_audio.c | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/sound/soc/fsl/fsl_qmc_audio.c b/sound/soc/fsl/fsl_qmc_audio.c
index 5614a8b909edf..0be29ccc1ff7b 100644
--- a/sound/soc/fsl/fsl_qmc_audio.c
+++ b/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->qmc_chans[i], &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.rx_ts_mask);
+
+               if (prev_last_rx_ts > last_rx_ts) {
+                       dev_err(qmc_audio->dev, "dai %d QMC chan %d unordered 
channels (RX timeslot %lu before %lu)\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 %lu before %lu)\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;
-- 
2.49.0