linux-kernel - Re: [PATCH v4 0/2] mux: gpio-mux: add enable GPIO support

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Message-ID: <CAD++jLnTM2u0pD3EddbfpmAHY_SDb-cm+5kfEWWEF9o0i5LSmw@mail.gmail.com>
Date: Mon, 19 Jan 2026 00:18:58 +0100
From: Linus Walleij <linusw@...nel.org>
To: Antoniu Miclaus <antoniu.miclaus@...log.com>
Cc: Peter Rosin <peda@...ntia.se>, Rob Herring <robh@...nel.org>, 
	Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>, 
	Srinivas Kandagatla <srini@...nel.org>, Johan Hovold <johan+linaro@...nel.org>, 
	David Lechner <dlechner@...libre.com>, devicetree@...r.kernel.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 0/2] mux: gpio-mux: add enable GPIO support

Hi Antoniu,

thanks for your patch!

On Fri, Jan 16, 2026 at 4:38 PM Antoniu Miclaus
<antoniu.miclaus@...log.com> wrote:

> This series adds optional enable GPIO support to the gpio-mux driver.
> The enable GPIO allows the multiplexer to be disabled before changing
> address lines and re-enabled after, preventing glitches that could
> briefly activate unintended channels during transitions.
>
> This feature is useful for devices like the Analog Devices ADG2404
> (4:1 mux) that require enable control for glitch-free operation. The
> binding documentation now includes ADG2404 as a supported device with
> a dedicated example.

Overall the idea is sound!

I don't know if "enable" is a good name for this GPIO though,
because as I understand it the signal passes through the mux even
if it is "disabled"?

I would call it "hold" and make it active low if it holds the mux
state when this signal is low.

hold-gpios = <&gpio 0 GPIO_ACTIVE_LOW>;

this will have the intended semantic.

Yours,
Linus Walleij