Commit af96ff5b authored Aug 04, 2014 by Nicolin Chen Committed by Mark Brown Aug 16, 2014

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



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>
Signed-off-by: Mark Brown <broonie@linaro.org>

parent 376d1a92

sound/soc/fsl/fsl_sai.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -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);

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