ASoC: davinci: fix sample rotation

McASP serial audio engine needs different rotation values on TX and RX
channels. Commit dde109fb462 ("ASoC: McASP: Fix data rotation for
playback. Enables 24bit audio playback") changed the calculation to fix
the playback format, but broke the capture stream by doing it for both
TXFMT and RXFMT.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@vger.kernel.org [3.9 only]

sound/soc/davinci/davinci-mcasp.c

@@ -631,7 +631,8 @@ static int davinci_config_channel_size(struct davinci_audio_dev *dev,
 				       int word_length)
 {
 	u32 fmt;
-	u32 rotate = (word_length / 4) & 0x7;
+	u32 tx_rotate = (word_length / 4) & 0x7;
+	u32 rx_rotate = (32 - word_length) / 4;
 	u32 mask = (1ULL << word_length) - 1;
 
 	/*
@@ -655,9 +656,9 @@ static int davinci_config_channel_size(struct davinci_audio_dev *dev,
 		mcasp_mod_bits(dev->base + DAVINCI_MCASP_TXFMT_REG,
 				TXSSZ(fmt), TXSSZ(0x0F));
 		mcasp_mod_bits(dev->base + DAVINCI_MCASP_TXFMT_REG,
-				TXROT(rotate), TXROT(7));
+				TXROT(tx_rotate), TXROT(7));
 		mcasp_mod_bits(dev->base + DAVINCI_MCASP_RXFMT_REG,
-				RXROT(rotate), RXROT(7));
+				RXROT(rx_rotate), RXROT(7));
 		mcasp_set_reg(dev->base + DAVINCI_MCASP_RXMASK_REG,
 				mask);
 	}