ASoC: tlv320dac33: Add option for keeping the BCLK running

Platform data option for the codec to keep the BCLK clock
continuously running in FIFO modes (codec master).

OMAP3 McBSP when in slave mode needs continuous BCLK running
on the serial bus in order to operate correctly.

Since in FIFO mode the DAC33 can also shut down the BCLK clock
and enable it only when it is needed, let the platforms decide
if the CPU side needs the BCLK running or not.
Signed-off-by: NPeter Ujfalusi <peter.ujfalusi@nokia.com>
Acked-by: NLiam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

include/sound/tlv320dac33-plat.h

@@ -15,6 +15,7 @@
 
 struct tlv320dac33_platform_data {
 	int power_gpio;
+	int keep_bclk;	/* Keep the BCLK running in FIFO modes */
 	u8 burst_bclkdiv;
 };
 

sound/soc/codecs/tlv320dac33.c

@@ -93,6 +93,8 @@ struct tlv320dac33_priv {
 	unsigned int nsample;		/* burst read amount from host */
 	u8 burst_bclkdiv;		/* BCLK divider value in burst mode */
 
+	int keep_bclk;			/* Keep the BCLK continuously running
+					 * in FIFO modes */
 	enum dac33_state state;
 };
 
@@ -803,7 +805,10 @@ static int dac33_prepare_chip(struct snd_pcm_substream *substream)
 		 */
 		fifoctrl_a &= ~DAC33_FBYPAS;
 		fifoctrl_a &= ~DAC33_FAUTO;
-		aictrl_b &= ~DAC33_BCLKON;
+		if (dac33->keep_bclk)
+			aictrl_b |= DAC33_BCLKON;
+		else
+			aictrl_b &= ~DAC33_BCLKON;
 		break;
 	case DAC33_FIFO_MODE7:
 		/*
@@ -814,7 +819,10 @@ static int dac33_prepare_chip(struct snd_pcm_substream *substream)
 		 */
 		fifoctrl_a &= ~DAC33_FBYPAS;
 		fifoctrl_a |= DAC33_FAUTO;
-		aictrl_b &= ~DAC33_BCLKON;
+		if (dac33->keep_bclk)
+			aictrl_b |= DAC33_BCLKON;
+		else
+			aictrl_b &= ~DAC33_BCLKON;
 		break;
 	default:
 		/*
@@ -1234,6 +1242,7 @@ static int __devinit dac33_i2c_probe(struct i2c_client *client,
 
 	dac33->power_gpio = pdata->power_gpio;
 	dac33->burst_bclkdiv = pdata->burst_bclkdiv;
+	dac33->keep_bclk = pdata->keep_bclk;
 	dac33->irq = client->irq;
 	dac33->nsample = NSAMPLE_MAX;
 	/* Disable FIFO use by default */