ASoC: davinci-mcasp: Format data delay configuration enhancement

Use intermediate variable for the data delay needed for the specific format
and write the register after the format configuration at once.
This will help to control the number of lines as support for more formats
going to be added.
Also fixes a case when we switch between two formats with different delay
requirements.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/davinci/davinci-mcasp.c

@@ -271,6 +271,7 @@ static int davinci_mcasp_set_dai_fmt(struct snd_soc_dai *cpu_dai,
 {
 	struct davinci_mcasp *mcasp = snd_soc_dai_get_drvdata(cpu_dai);
 	int ret = 0;
+	u32 data_delay;
 
 	pm_runtime_get_sync(mcasp->dev);
 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
@@ -278,18 +279,25 @@ static int davinci_mcasp_set_dai_fmt(struct snd_soc_dai *cpu_dai,
 	case SND_SOC_DAIFMT_AC97:
 		mcasp_clr_bits(mcasp, DAVINCI_MCASP_TXFMCTL_REG, FSXDUR);
 		mcasp_clr_bits(mcasp, DAVINCI_MCASP_RXFMCTL_REG, FSRDUR);
+
+		/* No delay after FS */
+		data_delay = 0;
 		break;
 	default:
 		/* configure a full-word SYNC pulse (LRCLK) */
 		mcasp_set_bits(mcasp, DAVINCI_MCASP_TXFMCTL_REG, FSXDUR);
 		mcasp_set_bits(mcasp, DAVINCI_MCASP_RXFMCTL_REG, FSRDUR);
 
-		/* make 1st data bit occur one ACLK cycle after the frame sync */
-		mcasp_set_bits(mcasp, DAVINCI_MCASP_TXFMT_REG, FSXDLY(1));
-		mcasp_set_bits(mcasp, DAVINCI_MCASP_RXFMT_REG, FSRDLY(1));
+		/* 1st data bit occur one ACLK cycle after the frame sync */
+		data_delay = 1;
 		break;
 	}
 
+	mcasp_mod_bits(mcasp, DAVINCI_MCASP_TXFMT_REG, FSXDLY(data_delay),
+		       FSXDLY(3));
+	mcasp_mod_bits(mcasp, DAVINCI_MCASP_RXFMT_REG, FSRDLY(data_delay),
+		       FSRDLY(3));
+
 	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
 	case SND_SOC_DAIFMT_CBS_CFS:
 		/* codec is clock and frame slave */