[PATCH 1/1] ASoC: codec: wm8960: add additional probe check for codec identification

[Frank Li]

The wm8960 codec is not readable, resulting in a NACK for address 0x3d (8-bit).
This can partially indicate it. For example: wm8962 codec use the same address
but is readable. This additional probe check will help prevent loading the wm8960
module incorrectly on wm8962 hardware.

Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
---
 sound/soc/codecs/wm8960.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c
index 0d167238a369..783c85912c59 100644
--- a/sound/soc/codecs/wm8960.c
+++ b/sound/soc/codecs/wm8960.c
@@ -1415,6 +1415,7 @@ static int wm8960_i2c_probe(struct i2c_client *i2c)
 	struct wm8960_data *pdata = dev_get_platdata(&i2c->dev);
 	struct wm8960_priv *wm8960;
 	int ret;
+	u8 val;
 
 	wm8960 = devm_kzalloc(&i2c->dev, sizeof(struct wm8960_priv),
 			      GFP_KERNEL);
@@ -1436,6 +1437,12 @@ static int wm8960_i2c_probe(struct i2c_client *i2c)
 	else if (i2c->dev.of_node)
 		wm8960_set_pdata_from_of(i2c, &wm8960->pdata);
 
+	ret = i2c_master_recv(i2c, &val, sizeof(val));
+	if (ret >= 0) {
+		dev_err(&i2c->dev, "Not wm8960, wm8960 reg can not read by i2c\n");
+		return -EINVAL;
+	}
+
 	ret = wm8960_reset(wm8960->regmap);
 	if (ret != 0) {
 		dev_err(&i2c->dev, "Failed to issue reset\n");
-- 
2.34.1