linux-kernel - Re: [PATCH 2/2] leds: triggers: gpio: Rewrite to use trigger-sources

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Message-ID: <20230915141549.GA3658872-robh@kernel.org>
Date:   Fri, 15 Sep 2023 09:15:49 -0500
From:   Rob Herring <robh@...nel.org>
To:     Linus Walleij <linus.walleij@...aro.org>
Cc:     Jan Kundrát <jan.kundrat@...net.cz>,
        Pavel Machek <pavel@....cz>, Lee Jones <lee@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Conor Dooley <conor+dt@...nel.org>,
        Jacek Anaszewski <jacek.anaszewski@...il.com>,
        linux-leds@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] leds: triggers: gpio: Rewrite to use trigger-sources

On Tue, Sep 12, 2023 at 03:44:31PM +0200, Linus Walleij wrote:
> By providing a GPIO line as "trigger-sources" in the FWNODE
> (such as from the device tree) and combining with the
> GPIO trigger, we can support a GPIO LED trigger in a natural
> way from the hardware description instead of using the
> custom sysfs and deprecated global GPIO numberspace.
> 
> Example:
> 
> gpio: gpio@0 {
>     compatible "my-gpio";
>     gpio-controller;
>     #gpio-cells = <2>;
>     interrupt-controller;
>     #interrupt-cells = <2>;
>     #trigger-source-cells = <2>;
> };
> 
> leds {
>     compatible = "gpio-leds";
>     led-my-gpio {
>         label = "device:blue:myled";
>         gpios = <&gpio 0 GPIO_ACTIVE_HIGH>;
>         default-state = "off";
>         linux,default-trigger = "gpio";
>         trigger-sources = <&gpio 1 GPIO_ACTIVE_HIGH>;
>     };
> };
> 
> Make this the norm, unmark the driver as broken.
> 
> Delete the sysfs handling of GPIOs.
> 
> Since GPIO descriptors inherently can describe inversion,
> the inversion handling can just be deleted.
> 
> Signed-off-by: Linus Walleij <linus.walleij@...aro.org>
> ---

[...]

> @@ -167,16 +78,47 @@ ATTRIBUTE_GROUPS(gpio_trig);
>  static int gpio_trig_activate(struct led_classdev *led)
>  {
>  	struct gpio_trig_data *gpio_data;
> +	struct device *dev = led->dev;
> +	int ret;
>  
>  	gpio_data = kzalloc(sizeof(*gpio_data), GFP_KERNEL);
>  	if (!gpio_data)
>  		return -ENOMEM;
>  
> -	gpio_data->led = led;
> -	gpio_data->gpio = -ENOENT;
> +	/*
> +	 * The generic property "trigger-sources" is followed,
> +	 * and we hope that this is a GPIO.
> +	 */
> +	gpio_data->gpiod = fwnode_gpiod_get_index(dev->fwnode,
> +						  "trigger-sources",
> +						  0, GPIOD_IN,
> +						  "led-trigger");

Isn't this going to look for "trigger-sources-gpio" and 
""trigger-sources-gpios"?

Rob