[alsa-devel] [PATCH v2 3/3] ASoC: fsl_sai: Fix TCSR.TE/RCSR.RE in synchronous mode

Daniel Baluta daniel.baluta at nxp.com
Fri Sep 13 21:28:07 CEST 2019


The SAI transmitter and receiver can be configured to operate with
synchronous bit clock and frame sync.

When Tx is synchronous with receiver RCSR.RE should be set in playback
to enable the receiver which provides bit clock and frame sync.

When Rx is synchronous with transmitter TCSR.TE should be set in record
to enable the transmitter which provides bit clock and frame sync.

Cc: NXP Linux Team <linux-imx at nxp.com>
Signed-off-by: Daniel Baluta <daniel.baluta at nxp.com>
---
Changes since v1: 
* new patch

 sound/soc/fsl/fsl_sai.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
index 6598a1ae0a2d..a59300e37549 100644
--- a/sound/soc/fsl/fsl_sai.c
+++ b/sound/soc/fsl/fsl_sai.c
@@ -539,8 +539,8 @@ static int fsl_sai_trigger(struct snd_pcm_substream *substream, int cmd,
 			   sai->synchronous[RX] ? FSL_SAI_CR2_SYNC : 0);
 
 	/*
-	 * It is recommended that the transmitter is the last enabled
-	 * and the first disabled.
+	 * it is recommended that the asynchronous block to be the last enabled
+	 * and the first disabled
 	 */
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
@@ -549,9 +549,11 @@ static int fsl_sai_trigger(struct snd_pcm_substream *substream, int cmd,
 		regmap_update_bits(sai->regmap, FSL_SAI_xCSR(tx, ofs),
 				   FSL_SAI_CSR_FRDE, FSL_SAI_CSR_FRDE);
 
-		regmap_update_bits(sai->regmap, FSL_SAI_RCSR(ofs),
-				   FSL_SAI_CSR_TERE, FSL_SAI_CSR_TERE);
-		regmap_update_bits(sai->regmap, FSL_SAI_TCSR(ofs),
+		if (sai->synchronous[tx])
+			regmap_update_bits(sai->regmap, FSL_SAI_xCSR(!tx, ofs),
+					   FSL_SAI_CSR_TERE, FSL_SAI_CSR_TERE);
+
+		regmap_update_bits(sai->regmap, FSL_SAI_xCSR(tx, ofs),
 				   FSL_SAI_CSR_TERE, FSL_SAI_CSR_TERE);
 
 		regmap_update_bits(sai->regmap, FSL_SAI_xCSR(tx, ofs),
-- 
2.17.1



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