On Mon, Sep 9, 2024 at 8:31 AM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote: > > Hi Rob, > > On Mon, Sep 9, 2024 at 3:07 PM Rob Herring <robh@xxxxxxxxxx> wrote: > > On Mon, Sep 9, 2024 at 5:58 AM Wolfram Sang > > <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > > > Most I2C controllers do not have a dedicated pin for SMBus Alerts. Allow > > > them to define a GPIO as a side-channel. > > > > Most GPIOs are also interrupts, so shouldn't the existing binding be > > sufficient? The exception is if the GPIO needs to be polled. > > If the GPIO pin supports multiple functions, it must be configured as > a GPIO first. devm_gpiod_get() takes care of that. Just calling > request_irq() does not. In addition, the mapping from GPIO to IRQ > number may not be fixed, e.g. in case the GPIO controller supports > less interrupt inputs than GPIOs, and needs to map them when requested. All sounds like Linux problems... > See also the different handling of interrupts and gpios by gpio-keys. I believe "gpios" is what was originally supported, but now it is preferred if GPIOs are used as interrupts then we use interrupts in DT. Rob
