Re: [PATCH v3 1/2] iio: proximity: vl53l0x-i2c: Added sensor ID check

[Jonathan Cameron <jic23@kernel.org>]

On Tue,  3 Sep 2024 09:26:35 +0530
Abhash Jha <abhashkumarjha123@gmail.com> wrote:

> The commit adds a check for the sensor's model ID. We read the model
> identification register (0xC0) and expect a value of 0xEE.
> 
> Signed-off-by: Abhash Jha <abhashkumarjha123@gmail.com>
Hi Abhash,

Small comment on the message below

> ---
>  drivers/iio/proximity/vl53l0x-i2c.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iio/proximity/vl53l0x-i2c.c b/drivers/iio/proximity/vl53l0x-i2c.c
> index 8d4f3f849..31d6aeb95 100644
> --- a/drivers/iio/proximity/vl53l0x-i2c.c
> +++ b/drivers/iio/proximity/vl53l0x-i2c.c
> @@ -39,8 +39,11 @@
>  
>  #define VL_REG_RESULT_INT_STATUS			0x13
>  #define VL_REG_RESULT_RANGE_STATUS			0x14
> +#define VL_REG_IDENTIFICATION_MODEL_ID			0xC0
>  #define VL_REG_RESULT_RANGE_STATUS_COMPLETE		BIT(0)
>  
> +#define VL53L0X_MODEL_ID_VAL				0xEE
> +
>  struct vl53l0x_data {
>  	struct i2c_client *client;
>  	struct completion completion;
> @@ -223,6 +226,7 @@ static int vl53l0x_probe(struct i2c_client *client)
>  	struct vl53l0x_data *data;
>  	struct iio_dev *indio_dev;
>  	int error;
> +	int ret;
>  
>  	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
>  	if (!indio_dev)
> @@ -237,6 +241,13 @@ static int vl53l0x_probe(struct i2c_client *client)
>  				     I2C_FUNC_SMBUS_BYTE_DATA))
>  		return -EOPNOTSUPP;
>  
> +	ret = i2c_smbus_read_byte_data(data->client, VL_REG_IDENTIFICATION_MODEL_ID);
> +	if (ret < 0)
> +		return -EINVAL;
> +
> +	if (ret != VL53L0X_MODEL_ID_VAL)
> +		dev_info(&client->dev, "Received invalid model id: 0x%x", ret);
Unknown model id:

It's probably valid, we just don't know what it means!

> +
>  	data->vdd_supply = devm_regulator_get(&client->dev, "vdd");
>  	if (IS_ERR(data->vdd_supply))
>  		return dev_err_probe(&client->dev, PTR_ERR(data->vdd_supply),
> @@ -265,8 +276,6 @@ static int vl53l0x_probe(struct i2c_client *client)
>  
>  	/* usage of interrupt is optional */
>  	if (client->irq) {
> -		int ret;
> -
>  		init_completion(&data->completion);
>  
>  		ret = vl53l0x_configure_irq(client, indio_dev);