Re: [PATCH v2 4/5] iio: mcp9600: Add support for dtbinding of thermocouple-type

[David Lechner <dlechner@baylibre.com>]

On 8/13/25 10:15 AM, Ben Collins wrote:
> Adds dtbinding check for thermocouple-type and sets sensor config
> to match. Add iio info attribute to show state as well.
> 
> Signed-off-by: Ben Collins <bcollins@watter.com>
> ---

...

> @@ -447,6 +492,20 @@ static int mcp9600_probe(struct i2c_client *client)
>  	data = iio_priv(indio_dev);
>  	data->client = client;
>  
> +	/* Accept type from dt with default of Type-K. */
> +	data->thermocouple_type = THERMOCOUPLE_TYPE_K;
> +	ret = device_property_read_u32(&client->dev, "thermocouple-type",
> +				       &data->thermocouple_type);

ret is not checked. We should either check it or drop it and add
a comment explaining why it is OK to ignore the return value.

Typically, for optional properties, we would ignore only -EINVAL
meaning the property is not present and fail on other errors.

We also need another dt-bindings patch to add the default in the
bindings.

> +	if (data->thermocouple_type >= ARRAY_SIZE(mcp9600_type_map))
> +		return dev_err_probe(&client->dev, -EINVAL,
> +				     "Invalid thermocouple-type property %d.\n",
> +				     data->thermocouple_type);
> +
> +	/* Set initial config. */
> +	ret = mcp9600_config(data);
> +	if (ret < 0)
> +		return ret;
> +
>  	ch_sel = mcp9600_probe_alerts(indio_dev);
>  	if (ch_sel < 0)
>  		return ch_sel;