Hallo Hermes, thanks for your effort. Am Donnerstag, 11. März 2021, 14:04:08 CET schrieb Hermes Zhang: > From: Hermes Zhang <chenhuiz@xxxxxxxx> > > Introduce a new Dual GPIO LED driver. These two GPIOs LED will act as > one LED as normal GPIO LED but give the possibility to change the > intensity in four levels: OFF, LOW, MIDDLE and HIGH. Interesting use case. Is there any real world hardware wired like that you could point to? > +config LEDS_DUAL_GPIO > + tristate "LED Support for Dual GPIO connected LEDs" > + depends on LEDS_CLASS > + depends on GPIOLIB || COMPILE_TEST > + help > + This option enables support for the two LEDs connected to GPIO > + outputs. These two GPIO LEDs act as one LED in the sysfs and > + perform different intensity by enable either one of them or both. Well, although I never had time to implement that, I suspect that could conflict if someone will eventually write a driver for two pin dual color LEDs connected to GPIO pins. We actually do that on our hardware and I know others do, too. I asked about that back in 2019, see this thread: https://www.spinics.net/lists/linux-leds/msg11665.html At the time the multicolor framework was not yet merged, so today I would probably make something which either uses the multicolor framework or at least has a similar interface to userspace. However, it probably won't surprise you all, this is not highest priority on my ToDo list. ;-) (What we actually do is pretend those are separate LEDs and ignore the conflicting case where both GPIOs are on and the LED is dark then.) Greets Alex
