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

Marek Vasut
2013-01-30T16:15:44Z

Dear Otavio Salvador,

> On Wed, Jan 30, 2013 at 2:05 PM, Marek Vasut <marex@denx.de> wrote:
> > Dear Otavio Salvador,
> >
> >> On Wed, Jan 30, 2013 at 1:39 PM, Marek Vasut <marex@denx.de> wrote:
> >> > Dear Otavio Salvador,
> >> >
> >> >> On Wed, Jan 30, 2013 at 12:13 PM, Marek Vasut <marex@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@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);
> >>
> >> }
> >> ...
> >
> > Ok, this didn't explain much to me.
> >
> >> > Moreover, you never set the LED GPIO as output.
> >>
> >> The driver handles it by itself.
> >
> > Oh ok.
> >
> > Now that I did read through the code, I have few more questions:
> >
> > Why can't STATUS_LED_BIT be the MX23_PAD_SSP1_DETECT__GPIO_2_1 now?
>
> It can but than we need to include the iomux-mx23.h header. It in the
> end is the same thing.

In the end, when I read the code in two hours, I'll be wondering what this magic
junk is. Thus, we will go for this and apply the adjustment for iomux.

Best regards,
Marek Vasut