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

[Ricardo Ribalda Delgado]

On Mon, Sep 2, 2024 at 11:53 PM André Apitzsch via B4 Relay
<devnull+git.apitzsch.eu@xxxxxxxxxx> wrote:
>
> From: André Apitzsch <git@xxxxxxxxxxx>
>
> Check the chip ID and stop probing if it is no imx214 sensor.
>
> Signed-off-by: André Apitzsch <git@xxxxxxxxxxx>
Acked-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>

> ---
>  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 ce6d8a90f4a1..6493a9b9ea88 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
> @@ -1168,6 +1172,27 @@ 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;
> @@ -1261,6 +1286,10 @@ 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);
>
> --
> 2.46.0
>
>