Hi Magnus,
On Mon, Jun 22, 2020 at 2:51 PM Magnus Damm <magnus.damm@xxxxxxxxx> wrote:
> From: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>
>
> This patch adds support for a couple of LEDs on the r8a77995 Draak board.
>
> It also ignores the issue that push switches are also used on the same GPIOs.
>
> The approach is the same as in the earlier posted patch for other boards:
> [PATCH/RFC] arm64: dts: renesas: salvator-common: gpio-leds prototype
>
> The limitations of DT bindings and kernel software support remain the same.
>
> As Geert pointed out we need to extend the software to allow sharing of
> GPIOs somehow. On this board and several others the GPIOs used for LEDs
> are also used for push switches. Both DT bindings and drivers need to
> be extended, most likely together with the GPIO subsystem. And to make it
> more fun it is probably possible to get interrupts from these GPIOs as well.
>
> In the patch the LED order and the GPIO number assignments look quite random
> but match the schematics.
>
> Signed-off-by: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> --- 0001/arch/arm64/boot/dts/renesas/r8a77995-draak.dts
> +++ work/arch/arm64/boot/dts/renesas/r8a77995-draak.dts 2020-06-22 21:00:20.000000000 +0900
> @@ -91,6 +91,20 @@
> };
> };
>
> + leds {
> + compatible = "gpio-leds";
> +
> + led13 {
While a name like "led13" is still considered acceptable these days, the
preferred format uses a hyphen ("^led-[0-9a-f]$"; whoops no one thought of
more than 16 LEDs?)
> + gpios = <&gpio4 7 GPIO_ACTIVE_HIGH>;
> + };
> + led12 {
> + gpios = <&gpio1 30 GPIO_ACTIVE_HIGH>;
> + };
> + led14 {
> + gpios = <&gpio4 25 GPIO_ACTIVE_HIGH>;
> + };
> + };
> +
> memory@48000000 {
> device_type = "memory";
> /* first 128MB is reserved for secure area. */
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
