[v2,3/3] ASoC: fsl_sai: Fix TCSR.TE/RCSR.RE in synchronous mode
diff mbox series

Message ID 20190913192807.8423-4-daniel.baluta@nxp.com
State New
Headers show
Series
  • Several SAI fixes
Related show

Commit Message

Daniel Baluta Sept. 13, 2019, 7:28 p.m. UTC
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@nxp.com>
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
---
Changes since v1: 
* new patch

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

Comments

Nicolin Chen Sept. 16, 2019, 11:11 p.m. UTC | #1
Hello Daniel,

On Fri, Sep 13, 2019 at 10:28:07PM +0300, Daniel Baluta wrote:
> 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.

I don't quite get what this patch fixes....can you explain?

> @@ -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.

This is copied from iMX6SX Reference Manual, IIRC...And I just
took a look at iMX8DXP/QXP RM: it has the exact same statement
in "16.16.3.3.1 Synchronous mode" section.

> +	 * it is recommended that the asynchronous block to be the last enabled
> +	 * and the first disabled

So... why are we changing to this? Any update/explain?

Thank you

Patch
diff mbox series

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),