[PATCH 3/4] soc-cache: add i2c read entry for 8_8 mode

[Barry Song <21cnbao-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

From: Cliff Cai <cliff.cai-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>

Signed-off-by: Cliff Cai <cliff.cai-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Barry Song <barry.song-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>
---
 sound/soc/soc-cache.c |   35 +++++++++++++++++++++++++++++++++++
 1 files changed, 35 insertions(+), 0 deletions(-)

diff --git a/sound/soc/soc-cache.c b/sound/soc/soc-cache.c
index bf593a8..91db7af 100644
--- a/sound/soc/soc-cache.c
+++ b/sound/soc/soc-cache.c
@@ -226,6 +226,40 @@ static unsigned int snd_soc_8_16_read(struct snd_soc_codec *codec,
 }
 
 #if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
+static unsigned int snd_soc_8_8_read_i2c(struct snd_soc_codec *codec,
+					  unsigned int r)
+{
+	struct i2c_msg xfer[2];
+	u8 reg = r;
+	u8 data;
+	int ret;
+	struct i2c_client *client = codec->control_data;
+
+	/* Write register */
+	xfer[0].addr = client->addr;
+	xfer[0].flags = 0;
+	xfer[0].len = 1;
+	xfer[0].buf = &reg;
+
+	/* Read data */
+	xfer[1].addr = client->addr;
+	xfer[1].flags = I2C_M_RD;
+	xfer[1].len = 1;
+	xfer[1].buf = &data;
+
+	ret = i2c_transfer(client->adapter, xfer, 2);
+	if (ret != 2) {
+		dev_err(&client->dev, "i2c_transfer() returned %d\n", ret);
+		return 0;
+	}
+
+	return data;
+}
+#else
+#define snd_soc_8_8_read_i2c NULL
+#endif
+
+#if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
 static unsigned int snd_soc_8_16_read_i2c(struct snd_soc_codec *codec,
 					  unsigned int r)
 {
@@ -466,6 +500,7 @@ static struct {
 	{
 		.addr_bits = 8, .data_bits = 8,
 		.write = snd_soc_8_8_write, .read = snd_soc_8_8_read,
+		.i2c_read = snd_soc_8_8_read_i2c,
 	},
 	{
 		.addr_bits = 8, .data_bits = 16,
-- 
1.5.6.3