On Tue, Mar 22, 2022 at 6:52 AM <haibo.chen@xxxxxxx> wrote: > From: Haibo Chen <haibo.chen@xxxxxxx> > > For some SoCs which contain different cores, like few ARM A cores > and few ARM M cores. Some GPIO controllers like GPIO3/GPIO4/GPIO5 > belong to A core domain, some GPIO controllers like GPIO1/GPIO2 > belong to M core domain. Linux only cover A cores, without gpio > alias, we can get gpiochip0/gpiochip1/gpiochip2 to map the real > GPIO3/GPIO4/GPIO5, it's difficult for users to identify this map > relation, and hardcode the gpio device index. With gpio alias, > we can easily make gpiochip3 map to GPIO3, gpiochip4 map to GPIO4. > For GPIO controllers do not claim the alias, it will get one id > which larger than all the claimed aliases. > > Signed-off-by: Haibo Chen <haibo.chen@xxxxxxx> This is device tree related, adds semantics to aliases and needs a prerequisite patch to Documentation/devicetree/bindings/gpio/gpio.txt at the very least. Also that patch needs to CC to devicetree@xxxxxxxxxxxxxxx IIRC this has been suggested in the past. Yours, Linus Walleij
