* Define LEDs with mixed colors
@ 2021-09-01 8:39 hamza.farooq
2021-09-01 11:09 ` Pavel Machek
0 siblings, 1 reply; 4+ messages in thread
From: hamza.farooq @ 2021-09-01 8:39 UTC (permalink / raw)
To: Andy Shevchenko
Cc: Linux Kernel Mailing List, Linux LED Subsystem, Platform Driver,
henning.schild, jan.kiszka, Haeussler, Gerd
Hello all,
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.
Best,
Hamza
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: Define LEDs with mixed colors
2021-09-01 8:39 Define LEDs with mixed colors hamza.farooq
@ 2021-09-01 11:09 ` Pavel Machek
2021-09-01 11:24 ` hamza.farooq
0 siblings, 1 reply; 4+ messages in thread
From: Pavel Machek @ 2021-09-01 11:09 UTC (permalink / raw)
To: hamza.farooq
Cc: Andy Shevchenko, Linux Kernel Mailing List, Linux LED Subsystem,
Platform Driver, henning.schild, jan.kiszka, Haeussler, Gerd
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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
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^ permalink raw reply [flat|nested] 4+ messages in thread* RE: Define LEDs with mixed colors
2021-09-01 11:09 ` Pavel Machek
@ 2021-09-01 11:24 ` hamza.farooq
2021-11-01 12:18 ` Pavel Machek
0 siblings, 1 reply; 4+ messages in thread
From: hamza.farooq @ 2021-09-01 11:24 UTC (permalink / raw)
To: Pavel Machek
Cc: Andy Shevchenko, Linux Kernel Mailing List, Linux LED Subsystem,
Platform Driver, henning.schild, jan.kiszka, Haeussler, Gerd
> -----Original Message-----
> From: Pavel Machek <pavel@ucw.cz>
> Sent: Wednesday, September 1, 2021 1:09 PM
> To: Farooq, Muhammad Hamza (DI FA CTR IPC PRC2)
> <hamza.farooq@siemens.com>
> Cc: Andy Shevchenko <andy.shevchenko@gmail.com>; Linux Kernel Mailing
> List <linux-kernel@vger.kernel.org>; Linux LED Subsystem <linux-
> leds@vger.kernel.org>; Platform Driver <platform-driver-
> x86@vger.kernel.org>; Schild, Henning (T RDA IOT SES-DE)
> <henning.schild@siemens.com>; Kiszka, Jan (T RDA IOT)
> <jan.kiszka@siemens.com>; Haeussler, Gerd (ext) (DI FA CTR IPC PRC2)
> <gerd.haeussler.ext@siemens.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?
Right. It is possible to create orange color, and I want to use DT/ACPI to present this info to the userland.
>
> Can you take a look at Documentation/leds/leds-class-multicolor.rst?
Couldn't find a hint there therefore this email thread. I might eventually write a multicolor led-gpio driver so want to know how to handle mixed LED.
>
> Best regards,
> Pavel
> --
> http://www.livejournal.com/~pavelmachek
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: Define LEDs with mixed colors
2021-09-01 11:24 ` hamza.farooq
@ 2021-11-01 12:18 ` Pavel Machek
0 siblings, 0 replies; 4+ messages in thread
From: Pavel Machek @ 2021-11-01 12:18 UTC (permalink / raw)
To: hamza.farooq
Cc: Andy Shevchenko, Linux Kernel Mailing List, Linux LED Subsystem,
Platform Driver, henning.schild, jan.kiszka, Haeussler, Gerd
[-- Attachment #1: Type: text/plain, Size: 1635 bytes --]
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?
> Right. It is possible to create orange color, and I want to use DT/ACPI to present this info to the userland.
>
> >
> > Can you take a look at Documentation/leds/leds-class-multicolor.rst?
> Couldn't find a hint there therefore this email thread. I might eventually write a multicolor led-gpio driver so want to know how to handle mixed LED.
>
There's no similar driver in the tree, and we don't have estabilished
API. You are mostly on your own.
Best regards,
Pavel
--
http://www.livejournal.com/~pavelmachek
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^ permalink raw reply [flat|nested] 4+ messages in thread
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2021-09-01 8:39 Define LEDs with mixed colors hamza.farooq
2021-09-01 11:09 ` Pavel Machek
2021-09-01 11:24 ` hamza.farooq
2021-11-01 12:18 ` Pavel Machek
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