ASoC: McASP: calculate values for channel size

Change davinci_config_channel_size() to derive the values for XSSZ and
XROT in DAVINCI_MCASP_[RT]XFMT_REG from the configured word length
rather than hard-coding them in a switch/case block.

Also, by directly passing the word length to
davinci_config_channel_size(), we can get rid of the
DAVINCI_AUDIO_WORD_* enum.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c
index 7c24837..1b0aac9 100644
--- a/sound/soc/davinci/davinci-mcasp.c
+++ b/sound/soc/davinci/davinci-mcasp.c
@@ -619,57 +619,14 @@
 }
 
 static int davinci_config_channel_size(struct davinci_audio_dev *dev,
-				       int channel_size)
+				       int word_length)
 {
-	u32 fmt = 0;
-	u32 mask, rotate;
+	u32 fmt;
+	u32 rotate = (32 - word_length) / 4;
+	u32 mask = (1ULL << word_length) - 1;
 
-	switch (channel_size) {
-	case DAVINCI_AUDIO_WORD_8:
-		fmt = 0x03;
-		rotate = 6;
-		mask = 0x000000ff;
-		break;
-
-	case DAVINCI_AUDIO_WORD_12:
-		fmt = 0x05;
-		rotate = 5;
-		mask = 0x00000fff;
-		break;
-
-	case DAVINCI_AUDIO_WORD_16:
-		fmt = 0x07;
-		rotate = 4;
-		mask = 0x0000ffff;
-		break;
-
-	case DAVINCI_AUDIO_WORD_20:
-		fmt = 0x09;
-		rotate = 3;
-		mask = 0x000fffff;
-		break;
-
-	case DAVINCI_AUDIO_WORD_24:
-		fmt = 0x0B;
-		rotate = 2;
-		mask = 0x00ffffff;
-		break;
-
-	case DAVINCI_AUDIO_WORD_28:
-		fmt = 0x0D;
-		rotate = 1;
-		mask = 0x0fffffff;
-		break;
-
-	case DAVINCI_AUDIO_WORD_32:
-		fmt = 0x0F;
-		rotate = 0;
-		mask = 0xffffffff;
-		break;
-
-	default:
-		return -EINVAL;
-	}
+	/* mapping of the XSSZ bit-field as described in the datasheet */
+	fmt = (word_length >> 1) - 1;
 
 	mcasp_mod_bits(dev->base + DAVINCI_MCASP_RXFMT_REG,
 					RXSSZ(fmt), RXSSZ(0x0F));
@@ -856,19 +813,19 @@
 	case SNDRV_PCM_FORMAT_U8:
 	case SNDRV_PCM_FORMAT_S8:
 		dma_params->data_type = 1;
-		word_length = DAVINCI_AUDIO_WORD_8;
+		word_length = 8;
 		break;
 
 	case SNDRV_PCM_FORMAT_U16_LE:
 	case SNDRV_PCM_FORMAT_S16_LE:
 		dma_params->data_type = 2;
-		word_length = DAVINCI_AUDIO_WORD_16;
+		word_length = 16;
 		break;
 
 	case SNDRV_PCM_FORMAT_U24_3LE:
 	case SNDRV_PCM_FORMAT_S24_3LE:
 		dma_params->data_type = 3;
-		word_length = DAVINCI_AUDIO_WORD_24;
+		word_length = 24;
 		break;
 
 	case SNDRV_PCM_FORMAT_U24_LE:
@@ -876,7 +833,7 @@
 	case SNDRV_PCM_FORMAT_U32_LE:
 	case SNDRV_PCM_FORMAT_S32_LE:
 		dma_params->data_type = 4;
-		word_length = DAVINCI_AUDIO_WORD_32;
+		word_length = 32;
 		break;
 
 	default: