ASoC: tlv320dac33: Clean up the hardware configuration code

Use switch instead of if statements to configure FIFO bypass
and mode1.
With this change adding new FIFO mode is going to be easier,
and cleaner.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/tlv320dac33.c

@@ -707,7 +707,7 @@ static int dac33_prepare_chip(struct snd_pcm_substream *substream)
 	struct snd_soc_codec *codec = socdev->card->codec;
 	struct tlv320dac33_priv *dac33 = codec->private_data;
 	unsigned int oscset, ratioset, pwr_ctrl, reg_tmp;
-	u8 aictrl_a, fifoctrl_a;
+	u8 aictrl_a, aictrl_b, fifoctrl_a;
 
 	switch (substream->runtime->rate) {
 	case 44100:
@@ -764,6 +764,7 @@ static int dac33_prepare_chip(struct snd_pcm_substream *substream)
 	dac33_oscwait(codec);
 
 	if (dac33->fifo_mode) {
+		/* Generic for all FIFO modes */
 		/* 50-51 : ASRC Control registers */
 		dac33_write(codec, DAC33_ASRC_CTRL_A, (1 << 4)); /* div=2 */
 		dac33_write(codec, DAC33_ASRC_CTRL_B, 1); /* ??? */
@@ -773,38 +774,66 @@ static int dac33_prepare_chip(struct snd_pcm_substream *substream)
 
 		/* Set interrupts to high active */
 		dac33_write(codec, DAC33_INTP_CTRL_A, DAC33_INTPM_AHIGH);
-
-		dac33_write(codec, DAC33_FIFO_IRQ_MODE_B,
-			    DAC33_ATM(DAC33_FIFO_IRQ_MODE_LEVEL));
-		dac33_write(codec, DAC33_FIFO_IRQ_MASK, DAC33_MAT);
 	} else {
+		/* FIFO bypass mode */
 		/* 50-51 : ASRC Control registers */
 		dac33_write(codec, DAC33_ASRC_CTRL_A, DAC33_SRCBYP);
 		dac33_write(codec, DAC33_ASRC_CTRL_B, 0); /* ??? */
 	}
 
-	if (dac33->fifo_mode)
+	/* Interrupt behaviour configuration */
+	switch (dac33->fifo_mode) {
+	case DAC33_FIFO_MODE1:
+		dac33_write(codec, DAC33_FIFO_IRQ_MODE_B,
+			    DAC33_ATM(DAC33_FIFO_IRQ_MODE_LEVEL));
+		dac33_write(codec, DAC33_FIFO_IRQ_MASK, DAC33_MAT);
+		break;
+	default:
+		/* in FIFO bypass mode, the interrupts are not used */
+		break;
+	}
+
+	aictrl_b = dac33_read_reg_cache(codec, DAC33_SER_AUDIOIF_CTRL_B);
+
+	switch (dac33->fifo_mode) {
+	case DAC33_FIFO_MODE1:
+		/*
+		 * For mode1:
+		 * Disable the FIFO bypass (Enable the use of FIFO)
+		 * Select nSample mode
+		 * BCLK is only running when data is needed by DAC33
+		 */
 		fifoctrl_a &= ~DAC33_FBYPAS;
-	else
+		fifoctrl_a &= ~DAC33_FAUTO;
+		aictrl_b &= ~DAC33_BCLKON;
+		break;
+	default:
+		/*
+		 * For FIFO bypass mode:
+		 * Enable the FIFO bypass (Disable the FIFO use)
+		 * Set the BCLK as continous
+		 */
 		fifoctrl_a |= DAC33_FBYPAS;
-	dac33_write(codec, DAC33_FIFO_CTRL_A, fifoctrl_a);
+		aictrl_b |= DAC33_BCLKON;
+		break;
+	}
 
+	dac33_write(codec, DAC33_FIFO_CTRL_A, fifoctrl_a);
 	dac33_write(codec, DAC33_SER_AUDIOIF_CTRL_A, aictrl_a);
-	reg_tmp = dac33_read_reg_cache(codec, DAC33_SER_AUDIOIF_CTRL_B);
-	if (dac33->fifo_mode)
-		reg_tmp &= ~DAC33_BCLKON;
-	else
-		reg_tmp |= DAC33_BCLKON;
-	dac33_write(codec, DAC33_SER_AUDIOIF_CTRL_B, reg_tmp);
+	dac33_write(codec, DAC33_SER_AUDIOIF_CTRL_B, aictrl_b);
 
-	if (dac33->fifo_mode) {
+	switch (dac33->fifo_mode) {
+	case DAC33_FIFO_MODE1:
 		/* 20: BCLK divide ratio */
 		dac33_write(codec, DAC33_SER_AUDIOIF_CTRL_C, 3);
 
 		dac33_write16(codec, DAC33_ATHR_MSB,
 			      DAC33_THRREG(dac33->alarm_threshold));
-	} else {
+		break;
+	default:
+		/* BYPASS mode */
 		dac33_write(codec, DAC33_SER_AUDIOIF_CTRL_C, 32);
+		break;
 	}
 
 	mutex_unlock(&dac33->mutex);