On Thu, Jan 19, 2023 at 3:01 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
>
> Turn of_led_get() into a more generic __of_led_get() helper function,
> which can lookup LEDs in devicetree by either name or index.
>
> And use this new helper to add devicetree support to the generic
> (non devicetree specific) [devm_]led_get() function.
>
> This uses the standard devicetree pattern of adding a -names string array
> to map names to the indexes for an array of resources.
>
> Note the new led-names property for LED consumers is not added
> to the devicetree documentation because there seems to be no
> documentation for the leds property itself to extend it with this.
> It seems that how LED consumers should be described is not documented
> at all ATM.
>
> This patch is marked as RFC because of both the missing devicetree
> documentation and because there are no devicetree users of
> the generic [devm_]led_get() function for now.
FWIW,
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Yeah, it's a pity we have no documentation for the LED properties...
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---
> drivers/leds/led-class.c | 37 ++++++++++++++++++++++++++++---------
> 1 file changed, 28 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
> index 6dff57c41e96..22f658c750d1 100644
> --- a/drivers/leds/led-class.c
> +++ b/drivers/leds/led-class.c
> @@ -234,19 +234,18 @@ static struct led_classdev *led_module_get(struct device *led_dev)
> return led_cdev;
> }
>
> -/**
> - * of_led_get() - request a LED device via the LED framework
> - * @np: device node to get the LED device from
> - * @index: the index of the LED
> - *
> - * Returns the LED device parsed from the phandle specified in the "leds"
> - * property of a device tree node or a negative error-code on failure.
> - */
> -struct led_classdev *of_led_get(struct device_node *np, int index)
> +static struct led_classdev *__of_led_get(struct device_node *np, int index,
> + const char *name)
> {
> struct device *led_dev;
> struct device_node *led_node;
>
> + /*
> + * For named LEDs, first look up the name in the "led-names" property.
> + * If it cannot be found, then of_parse_phandle() will propagate the error.
> + */
> + if (name)
> + index = of_property_match_string(np, "led-names", name);
> led_node = of_parse_phandle(np, "leds", index);
> if (!led_node)
> return ERR_PTR(-ENOENT);
> @@ -256,6 +255,19 @@ struct led_classdev *of_led_get(struct device_node *np, int index)
>
> return led_module_get(led_dev);
> }
> +
> +/**
> + * of_led_get() - request a LED device via the LED framework
> + * @np: device node to get the LED device from
> + * @index: the index of the LED
> + *
> + * Returns the LED device parsed from the phandle specified in the "leds"
> + * property of a device tree node or a negative error-code on failure.
> + */
> +struct led_classdev *of_led_get(struct device_node *np, int index)
> +{
> + return __of_led_get(np, index, NULL);
> +}
> EXPORT_SYMBOL_GPL(of_led_get);
>
> /**
> @@ -329,9 +341,16 @@ EXPORT_SYMBOL_GPL(devm_of_led_get);
> struct led_classdev *led_get(struct device *dev, char *function)
> {
> struct led_lookup_data *lookup;
> + struct led_classdev *led_cdev;
> const char *led_name = NULL;
> struct device *led_dev;
>
> + if (dev->of_node) {
> + led_cdev = __of_led_get(dev->of_node, -1, function);
> + if (!IS_ERR(led_cdev) || PTR_ERR(led_cdev) != -ENOENT)
> + return led_cdev;
> + }
> +
> mutex_lock(&leds_lookup_lock);
> list_for_each_entry(lookup, &leds_lookup_list, list) {
> if (!strcmp(lookup->consumer_dev_name, dev_name(dev)) &&
> --
> 2.39.0
>
--
With Best Regards,
Andy Shevchenko
