On Mon, Jul 22, 2019 at 10:37 PM Hongwei Zhang <hongweiz@xxxxxxx> wrote: > As you suspected it correctly, AST2500 utilizes all the 32 bits of the registers > (data value, interrupt, etc...), such that using 8-bit bands > [7:0]/[15:8]/23:16]/[31:24] of GPIO_200H for SGPIO_A/B/C/D . > so registering 10 gpiochip drivers separately will make code more > complicated, for example gpio_200 register (data_value reg) has to be > shared by 4 gpiochip instances, and the same is true for gpio204 (interrupt reg), > and other more registers. > So we would prefer to keeping current implementation. OK this is a pretty good argument. My review assumed one 32-bit register was not shared between banks but it is, I see. The above situation can be managed by regmap, but that will just a different complexity so go with this approach then. Yours, Linus Walleij