Re: [PATCH 2/2] dt-binding: leds: Document leds-multi-gpio bindings

From: Vesa Jääskeläinen
Date: Sun Mar 28 2021 - 16:47:08 EST


Hi,

On 25.3.2021 20.41, Pavel Machek wrote:
+ led-gpios:
+ description: Array of one or more GPIOs pins used to control the LED.
+ minItems: 1
+ maxItems: 8 # Should be enough

We also have a case with multi color LEDs (which is probably a more common
than multi intensity LED. So I am wondering how these both could co-exist.

From: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/leds/leds-gpio.yaml?h=v5.12-rc4#n58

led-0 {
gpios = <&mcu_pio 0 GPIO_ACTIVE_LOW>;
linux,default-trigger = "disk-activity";
function = LED_FUNCTION_DISK;
};

Now 'gpios' (and in LED context) and 'led-gpios' is very close to each other
and could easily be confused.

Perhaps this could be something like:

intensity-gpios = ...

or even simplified then just to gpios = <...>

...
How would this sound?

Well, not too bad on a quick look.

Are you willing to implement such multi-color-multi-bit-multi-gpio
driver?

We have a need for multi color GPIO LED support so I can work on that if no one else gets there before me -- I do not have hardware with multiple GPIO lines controlling the brightness so that needs a bit more effort in order to test that out.

At some point of time I could also revive the PWM stuff if no one else beats me to it -- but probably the GPIO variant is easier to get done as binary states are easier.

Thanks,
Vesa Jääskeläinen