linux-kernel - Re: [RFC PATCH 09/13] gpio: Support ROHM BD72720 gpios

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Message-ID: <CACRpkdZSiZ_74Ar+tRzVSwRW=6XoUpODyxqZDFyrc-0pcHkaPg@mail.gmail.com>
Date: Mon, 13 Oct 2025 14:54:49 +0200
From: Linus Walleij <linus.walleij@...aro.org>
To: Matti Vaittinen <mazziesaccount@...il.com>
Cc: Matti Vaittinen <matti.vaittinen@...rohmeurope.com>, Lee Jones <lee@...nel.org>, 
	Pavel Machek <pavel@...nel.org>, Rob Herring <robh@...nel.org>, 
	Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>, 
	Sebastian Reichel <sre@...nel.org>, Liam Girdwood <lgirdwood@...il.com>, Mark Brown <broonie@...nel.org>, 
	Bartosz Golaszewski <brgl@...ev.pl>, Andreas Kemnade <andreas@...nade.info>, linux-leds@...r.kernel.org, 
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org, 
	linux-pm@...r.kernel.org, linux-gpio@...r.kernel.org
Subject: Re: [RFC PATCH 09/13] gpio: Support ROHM BD72720 gpios

On Tue, Oct 7, 2025 at 10:34 AM Matti Vaittinen
<mazziesaccount@...il.com> wrote:

> The ROHM BD72720 has 6 pins which may be configured as GPIOs. The
> GPIO1 ... GPIO5 and EPDEN pins. The configuration is done to OTP at the
> manufacturing, and it can't be read at runtime. The device-tree is
> required to tell the software which of the pins are used as GPIOs.
>
> Keep the pin mapping static regardless the OTP. This way the user-space
> can always access the BASE+N for GPIO(N+1) (N = 0 to 4), and BASE + 5
> for the EPDEN pin. Do this by setting always the number of GPIOs to 6,
> and by using the valid-mask to invalidate the pins which aren't configured
> as GPIOs.
>
> First two pins can be set to be either input or output by OTP. Direction
> can't be changed by software. Rest of the pins can be set as outputs
> only. All of the pins support generating interrupts.
>
> Support the Input/Output state getting/setting and the output mode
> configuration (open-drain/push-pull).
>
> Signed-off-by: Matti Vaittinen <mazziesaccount@...il.com>

Nice use of valid-mask here!
I don't know about the special pin binding but the driver
looks good.

Reviewed-by: Linus Walleij <linus.walleij@...aro.org>

Yours,
Linus Walleij