[U-Boot] [PATCH 06/10] mx23_olinuxino: Add support for status LED

[Otavio Salvador]

On Wed, Jan 30, 2013 at 1:39 PM, Marek Vasut <marex at denx.de> wrote:
> Dear Otavio Salvador,
>
>> On Wed, Jan 30, 2013 at 12:13 PM, Marek Vasut <marex at denx.de> wrote:
>> > Dear Otavio Salvador,
>> >
>> >> This allow user to know if the bootloader is running, even without a
>> >> serial console.
>> >>
>> >> Signed-off-by: Otavio Salvador <otavio at ossystems.com.br>
>> >
>> > Uh oh, how does this know which GPIO to toggle to drive the led this time
>> > ?
>>
>> The problem wasn't the code but me. I wasn't able to find the right
>> GPIO number at that time.
>
> This is not my question. My question is how does this toggle the GPIO for the
> LED?

gpio_led driver (drivers/misc/gpio_led.c) does it.

...
void __led_init(led_id_t mask, int state)
{
        gpio_request(mask, "gpio_led");
        gpio_direction_output(mask, state == STATUS_LED_ON);
}

void __led_set(led_id_t mask, int state)
{
        gpio_set_value(mask, state == STATUS_LED_ON);
}
...

> Moreover, you never set the LED GPIO as output.

The driver handles it by itself.

See above.

--
Otavio Salvador                             O.S. Systems
E-mail: otavio at ossystems.com.br  http://www.ossystems.com.br
Mobile: +55 53 9981-7854              http://projetos.ossystems.com.br