diff mbox

ASoC: fsl_sai: Set SYNC bit of TCR2 to Asynchronous Mode

Message ID 1407136045-8940-1-git-send-email-nicoleotsuka@gmail.com (mailing list archive)
State Accepted
Commit af96ff5b7448dc776dc24a5c4313c6ec1ee94e53
Headers show

Commit Message

Nicolin Chen Aug. 4, 2014, 7:07 a.m. UTC 
From: Nicolin Chen <Guangyu.Chen@freescale.com>

There is one design rule according to SAI's reference manual:
If the transmitter bit clock and frame sync are to be used by both transmitter
and receiver, the transmitter must be configured for asynchronous operation
and the receiver for synchronous operation.

And SYNC of TCR2 is a 2-width control bit:
00 Asynchronous mode.
01 Synchronous with receiver.
10 Synchronous with another SAI transmitter.
11 Synchronous with another SAI receiver.

So the driver should have set SYNC bit of TCR2 to 0x0, and meanwhile set SYNC
bit of RCR2 to 0x1 (Synchronous with transmitter).

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
---

@Mark
Sir, I don't see your last patch in your branch. So I guess we can still use
this better fix which does not have the 64bit compiling issue either. 

 sound/soc/fsl/fsl_sai.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

Comments

Mark Brown Aug. 4, 2014, 3:22 p.m. UTC | #1 
On Mon, Aug 04, 2014 at 03:07:25PM +0800, Nicolin Chen wrote:
> From: Nicolin Chen <Guangyu.Chen@freescale.com>
> 
> There is one design rule according to SAI's reference manual:
> If the transmitter bit clock and frame sync are to be used by both transmitter
> and receiver, the transmitter must be configured for asynchronous operation
> and the receiver for synchronous operation.

Applied, thanks.
diff mbox

Patch

diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
index faa0497..9f10575 100644
--- a/sound/soc/fsl/fsl_sai.c
+++ b/sound/soc/fsl/fsl_sai.c
@@ -333,8 +333,7 @@  static int fsl_sai_trigger(struct snd_pcm_substream *substream, int cmd,
 	 * The transmitter bit clock and frame sync are to be
 	 * used by both the transmitter and receiver.
 	 */
-	regmap_update_bits(sai->regmap, FSL_SAI_TCR2, FSL_SAI_CR2_SYNC,
-			   ~FSL_SAI_CR2_SYNC);
+	regmap_update_bits(sai->regmap, FSL_SAI_TCR2, FSL_SAI_CR2_SYNC, 0);
 	regmap_update_bits(sai->regmap, FSL_SAI_RCR2, FSL_SAI_CR2_SYNC,
 			   FSL_SAI_CR2_SYNC);