[PATCH 4/4] soc-cache: let reg be AND'ed by 0xff instead of data buffer for 8_8 mode

[Barry Song <21cnbao@gmail.com>]

The registers for AD193X are defined as 0x800-0x810 for spi which uses 16_8 mode,
for i2c to support AD1937, we will use 8_8 mode, only the low byte of 0x800-0x810
is valid.
The patch will not destory other codecs, but make soc cache interface more useful.

Signed-off-by: Barry Song <barry.song@analog.com>
---
 sound/soc/soc-cache.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/sound/soc/soc-cache.c b/sound/soc/soc-cache.c
index 91db7af..9dfe9a5 100644
--- a/sound/soc/soc-cache.c
+++ b/sound/soc/soc-cache.c
@@ -159,7 +159,8 @@ static int snd_soc_8_8_write(struct snd_soc_codec *codec, unsigned int reg,
 
 	BUG_ON(codec->volatile_register);
 
-	data[0] = reg & 0xff;
+	reg &= 0xff;
+	data[0] = reg;
 	data[1] = value & 0xff;
 
 	if (reg < codec->reg_cache_size)
@@ -180,6 +181,7 @@ static unsigned int snd_soc_8_8_read(struct snd_soc_codec *codec,
 				     unsigned int reg)
 {
 	u8 *cache = codec->reg_cache;
+	reg &= 0xff;
 	if (reg >= codec->reg_cache_size)
 		return -1;
 	return cache[reg];
-- 
1.5.6.3