linux-kernel - Re: Define LEDs with mixed colors

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20210901110929.GA18522@duo.ucw.cz>
Date:   Wed, 1 Sep 2021 13:09:29 +0200
From:   Pavel Machek <pavel@....cz>
To:     "hamza.farooq@...mens.com" <hamza.farooq@...mens.com>
Cc:     Andy Shevchenko <andy.shevchenko@...il.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Linux LED Subsystem <linux-leds@...r.kernel.org>,
        Platform Driver <platform-driver-x86@...r.kernel.org>,
        "henning.schild@...mens.com" <henning.schild@...mens.com>,
        "jan.kiszka@...mens.com" <jan.kiszka@...mens.com>,
        "Haeussler, Gerd" <gerd.haeussler.ext@...mens.com>
Subject: Re: Define LEDs with mixed colors

Hi!

> I am toying with the idea of writing a multicolor LED GPIO driver. What would be the right way to define mixed color LEDs (for leds-gpio), in device tree or ACPI?
> Consider the following:
> 
> leds {
> 	compatible = "gpio-leds";
> 	led0 {
> 		gpios = <&mcu_pio 0 GPIO_ACTIVE_LOW>;
> 		color = <LED_COLOR_ID_RED>;
> 	};
> 
> 	led1 {
> 		gpios = <&mcu_pio 1 GPIO_ACTIVE_HIGH>;
> 		color = <LED_COLOR_ID_GREEN>;
> 	};
> 	led2 {
> 		gpios = <&mcu_pio 0 GPIO_ACTIVE_LOW
> 			&mcu_pio 1 GPIO_ACTIVE_LOW>;
> 		color = <LED_COLOR_ID_AMBER>;
> 	};
> };
> 
> This probably won't work as "gpios" seem to be single object in gpio-leds driver code, but what can I do to achieve something similar?
> It is important to define this LED in DT/ACPI in order for the user app to see it in the /sys/class/led folder, without having to write platform-specific driver.
> 

So you have one package with red and green LED, each connected to one
GPIO?

Can you take a look at Documentation/leds/leds-class-multicolor.rst?

Best regards,
								Pavel
-- 
http://www.livejournal.com/~pavelmachek

Download attachment "signature.asc" of type "application/pgp-signature" (196 bytes)