Re: [PATCH v4 04/11] leds: led-class: Add generic [devm_]led_get()

[Andy Shevchenko <andy.shevchenko@xxxxxxxxx>]

On Thu, Jan 19, 2023 at 3:01 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
>
> Add a generic [devm_]led_get() method which can be used on both devicetree
> and non devicetree platforms to get a LED classdev associated with
> a specific function on a specific device, e.g. the privacy LED associated
> with a specific camera sensor.
>
> Note unlike of_led_get() this takes a string describing the function
> rather then an index. This is done because e.g. camera sensors might

than

> have a privacy LED, or a flash LED, or both and using an index
> approach leaves it unclear what the function of index 0 is if there is
> only 1 LED.
>
> This uses a lookup-table mechanism for non devicetree platforms.
> This allows the platform code to map specific LED class_dev-s to a specific
> device,function combinations this way.
>
> For devicetree platforms getting the LED by function-name could be made
> to work using the standard devicetree pattern of adding a -names string
> array to map names to the indexes.

...

> +/*
> + * This is used to tell led_get() device which led_classdev to return for
> + * a specific consumer device-name, function pair on non devicetree platforms.
> + * Note all strings must be set.
> + */
> +struct led_lookup_data {
> +       struct list_head list;
> +       const char *led_name;
> +       const char *consumer_dev_name;
> +       const char *consumer_function;
> +};

I'm wondering if it would be better to have something like

struct led_function_map {
       const char *name;
       const char *function;
};

struct led_lookup_data {
       struct list_head list;
       const char *dev_name;
       const struct led_function_map map[];
};

as you may have more than one LED per the device and it would be a
more compressed list in this case. I'm basically referring to the GPIO
lookup table.

-- 
With Best Regards,
Andy Shevchenko