I have a pcf8575 gpio expander (16 pins) and want to get even notification of rising edge interrupt, on one of the pins, in the userspace. I have made the following device tree changes to achieve the same:
gpio-keys {
compatible = "gpio-keys";
status = "okay";
back {
label = "Back";
gpios = <&pcf8575_h 8 GPIO_ACTIVE_HIGH>; // <---- Pin 8 to raise interrupt
interrupt-parent = <&pcf8575_h>; // <------ Is this required? Kernel Docs on gpio-keys do not mention interrupt-parent as a subproperty
interrupt = <8 IRQ_TYPE_EDGE_RISING>; // <-------- What should be the interrupt specifier here??
linux,code = <KEY_BACK>;
};
};
The pcf8575 gpio controller node (which is also interrupt controller) has one IRQ Line which is configured with IRQ_TYPE_EDGE_FALLING. What interrupt specifier should I have in the gpio-keys node so that I can achieve an interrupt on Pin 8 on rising edge?