[PATCH v2 12/13] media: i2c: imx214: Verify chip ID

[André Apitzsch via B4 Relay]

From: André Apitzsch <g...@apitzsch.eu>

Check the chip ID and stop probing if it is no imx214 sensor.

Acked-by: Ricardo Ribalda <riba...@chromium.org>
Signed-off-by: André Apitzsch <g...@apitzsch.eu>
---
 drivers/media/i2c/imx214.c | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/drivers/media/i2c/imx214.c b/drivers/media/i2c/imx214.c
index 
ad1f88057ac47ae0d494d7a10520fabf969315ed..46f3e27371d8075517a75891e6a742912c2a3604
 100644
--- a/drivers/media/i2c/imx214.c
+++ b/drivers/media/i2c/imx214.c
@@ -20,6 +20,10 @@
 #include <media/v4l2-fwnode.h>
 #include <media/v4l2-subdev.h>
 
+/* Chip ID */
+#define IMX214_REG_CHIP_ID             CCI_REG16(0x0016)
+#define IMX214_CHIP_ID                 0x0214
+
 #define IMX214_REG_MODE_SELECT         CCI_REG8(0x0100)
 #define IMX214_MODE_STANDBY            0x00
 #define IMX214_MODE_STREAMING          0x01
@@ -1153,6 +1157,27 @@ static int imx214_get_regulators(struct device *dev, 
struct imx214 *imx214)
                                       imx214->supplies);
 }
 
+/* Verify chip ID */
+static int imx214_identify_module(struct imx214 *imx214)
+{
+       struct i2c_client *client = v4l2_get_subdevdata(&imx214->sd);
+       int ret;
+       u64 val;
+
+       ret = cci_read(imx214->regmap, IMX214_REG_CHIP_ID, &val, NULL);
+       if (ret)
+               return dev_err_probe(&client->dev, ret,
+                                    "failed to read chip id %x\n",
+                                    IMX214_CHIP_ID);
+
+       if (val != IMX214_CHIP_ID)
+               return dev_err_probe(&client->dev, -EIO,
+                                    "chip id mismatch: %x!=%llx\n",
+                                    IMX214_CHIP_ID, val);
+
+       return 0;
+}
+
 static int imx214_parse_fwnode(struct device *dev, struct imx214 *imx214)
 {
        struct fwnode_handle *endpoint;
@@ -1245,6 +1270,10 @@ static int imx214_probe(struct i2c_client *client)
         */
        imx214_power_on(imx214->dev);
 
+       ret = imx214_identify_module(imx214);
+       if (ret)
+               goto error_power_off;
+
        pm_runtime_set_active(imx214->dev);
        pm_runtime_enable(imx214->dev);
        pm_runtime_idle(imx214->dev);

-- 
2.47.0