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Date:   Thu, 30 Sep 2021 09:00:49 +0100
Message-ID: <87fstmtrv2.wl-maz@kernel.org>
From:   Marc Zyngier <maz@kernel.org>
To:     Linus Walleij <linus.walleij@linaro.org>
Cc:     "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        linux-pci <linux-pci@vger.kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Rob Herring <robh+dt@kernel.org>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Krzysztof =?UTF-8?B?V2lsY3p5xYRza2k=?= <kw@linux.com>,
        Alyssa Rosenzweig <alyssa@rosenzweig.io>,
        Stan Skowronek <stan@corellium.com>,
        Mark Kettenis <kettenis@openbsd.org>,
        Sven Peter <sven@svenpeter.dev>,
        Hector Martin <marcan@marcan.st>,
        Robin Murphy <Robin.Murphy@arm.com>,
        Joey Gouly <joey.gouly@arm.com>,
        Joerg Roedel <joro@8bytes.org>,
        Android Kernel Team <kernel-team@android.com>
Subject: Re: [PATCH v5 10/14] arm64: apple: Add pinctrl nodes
In-Reply-To: <CACRpkdaXbrmvoQQNRdyv6rJ+dHYAKMN+J_sc-3_c1d6D2dsfbQ@mail.gmail.com>
References: <20210929163847.2807812-1-maz@kernel.org>
        <20210929163847.2807812-11-maz@kernel.org>
        <CACRpkdaXbrmvoQQNRdyv6rJ+dHYAKMN+J_sc-3_c1d6D2dsfbQ@mail.gmail.com>
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On Wed, 29 Sep 2021 20:05:42 +0100,
Linus Walleij <linus.walleij@linaro.org> wrote:
> 
> On Wed, Sep 29, 2021 at 6:56 PM Marc Zyngier <maz@kernel.org> wrote:
> 
> > From: Mark Kettenis <kettenis@openbsd.org>
> >
> > Add pinctrl nodes corresponding to the gpio,t8101 nodes in the
> > Apple device tree for the Mac mini (M1, 2020).
> >
> > Clock references are left out at the moment and will be added once
> > the appropriate bindings have been settled upon.
> >
> > Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
> > Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> > Signed-off-by: Marc Zyngier <maz@kernel.org>
> > Link: https://lore.kernel.org/r/20210520171310.772-3-mark.kettenis@xs4all.nl
> (...)
> > +               pinctrl_ap: pinctrl@23c100000 {
> > +                       compatible = "apple,t8103-pinctrl", "apple,pinctrl";
> > +                       reg = <0x2 0x3c100000 0x0 0x100000>;
> > +
> > +                       gpio-controller;
> > +                       #gpio-cells = <2>;
> > +                       gpio-ranges = <&pinctrl_ap 0 0 212>;
> 
> In other discussions it turns out that the driver is abusing these gpio-ranges
> to find out how many pins are in each pinctrl instance. This is not the
> idea with gpio-ranges, these can be multiple and map different sets,
> so we need something like
> 
> apple,npins = <212>;
> (+ bindings)
> 
> or so...

Is it the driver that needs updating? Or the binding? I don't really
care about the former, but the latter is more disruptive as it has
impacts over both u-boot and at least OpenBSD.

How is that solved on other pinctrl blocks? I can't see anyone having
a similar a similar property.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.