On Wed, May 13, 2020 at 4:11 PM Lars Povlsen <lars.povlsen@xxxxxxxxxxxxx> wrote:
> This adds DT bindings for the Microsemi SGPIO controller, bindings
> mscc,ocelot-sgpio and mscc,luton-sgpio.
>
> Reviewed-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
> Signed-off-by: Lars Povlsen <lars.povlsen@xxxxxxxxxxxxx>
> + microchip,sgpio-ports:
> + description: This is a 32-bit bitmask, configuring whether a
> + particular port in the controller is enabled or not. This allows
> + unused ports to be removed from the bitstream and reduce latency.
> + $ref: "/schemas/types.yaml#/definitions/uint32"
I don't know about this.
You are saying this pin controller can have up to 32 GPIO "ports"
(also known as banks).
Why can't you just represent each such port as a separate GPIO
node:
pinctrl@nnn {
gpio@0 {
....
};
gpio@1 {
....
};
....
gpio@31 {
....
};
};
Then if some of them are unused just set it to status = "disabled";
This also makes your Linux driver simpler because each GPIO port
just becomes a set of 32bit registers and you can use
select GPIO_GENERIC and bgpio_init() and save a whole
slew of standard stock code.
Yours,
Linus Walleij
