On Sat, 11 Mar 2023 12:14:56 +0100
Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> wrote:
> The driver currently matches only via i2c_device_id, but also has
> of_device_id table:
>
> drivers/iio/light/max44009.c:545:34: error: ‘max44009_of_match’ defined but not used [-Werror=unused-const-variable=]
>
> Fixes: 6aef699a7d7e ("iio: light: add driver for MAX44009")
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
Don't use of_match_ptr() unless you are absolutely sure no other firmware
route will make use of the of_match_table.
In this particular case ACPI using PRP0001 is broken by that macro.
So good to set the of_match_table, but make sure to always set it
and hence you don't need the __maybe_unused.
Jonathan
> ---
> drivers/iio/light/max44009.c | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/iio/light/max44009.c b/drivers/iio/light/max44009.c
> index 3dadace09fe2..274e0b679ca2 100644
> --- a/drivers/iio/light/max44009.c
> +++ b/drivers/iio/light/max44009.c
> @@ -527,6 +527,12 @@ static int max44009_probe(struct i2c_client *client)
> return devm_iio_device_register(&client->dev, indio_dev);
> }
>
> +static const struct of_device_id max44009_of_match[] __maybe_unused = {
> + { .compatible = "maxim,max44009" },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, max44009_of_match);
> +
> static const struct i2c_device_id max44009_id[] = {
> { "max44009", 0 },
> { }
> @@ -536,18 +542,13 @@ MODULE_DEVICE_TABLE(i2c, max44009_id);
> static struct i2c_driver max44009_driver = {
> .driver = {
> .name = MAX44009_DRV_NAME,
> + .of_match_table = of_match_ptr(max44009_of_match),
> },
> .probe_new = max44009_probe,
> .id_table = max44009_id,
> };
> module_i2c_driver(max44009_driver);
>
> -static const struct of_device_id max44009_of_match[] = {
> - { .compatible = "maxim,max44009" },
> - { }
> -};
> -MODULE_DEVICE_TABLE(of, max44009_of_match);
> -
> MODULE_AUTHOR("Robert Eshleman <bobbyeshleman@xxxxxxxxx>");
> MODULE_LICENSE("GPL v2");
> MODULE_DESCRIPTION("MAX44009 ambient light sensor driver");
