ASoC: fsl-ssi: Transmit enable synchronization

When the fsl-ssi unit is used in i2s slave mode, it is possible that the
SSI unit starts transmitting data on the wrong channel. This happens
because the SSI does not synchronize with the left-right-clock by
default.

This patch enables transmit enable synchronization.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Tested-By: Michael Grzeschik <mgr@pengutronix.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/fsl/fsl_ssi.c

@@ -589,6 +589,7 @@ static int fsl_ssi_set_dai_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt)
 	fsl_ssi_setup_reg_vals(ssi_private);
 
 	scr = read_ssi(&ssi->scr) & ~(CCSR_SSI_SCR_SYN | CCSR_SSI_SCR_I2S_MODE_MASK);
+	scr |= CCSR_SSI_SCR_SYNC_TX_FS;
 
 	mask = CCSR_SSI_STCR_TXBIT0 | CCSR_SSI_STCR_TFDIR | CCSR_SSI_STCR_TXDIR |
 		CCSR_SSI_STCR_TSCKP | CCSR_SSI_STCR_TFSI | CCSR_SSI_STCR_TFSL |

sound/soc/fsl/fsl_ssi.h

@@ -39,6 +39,7 @@ struct ccsr_ssi {
 	__be32 saccdis; /* 0x.0058 - SSI AC97 Channel Disable Register */
 };
 
+#define CCSR_SSI_SCR_SYNC_TX_FS		0x00001000
 #define CCSR_SSI_SCR_RFR_CLK_DIS	0x00000800
 #define CCSR_SSI_SCR_TFR_CLK_DIS	0x00000400
 #define CCSR_SSI_SCR_TCH_EN		0x00000100