Re: [PATCH v2 5/8] hw/arm/virt: Fix devicetree warnings about the GPIO node

From: Rob Herring <robh@kernel.org>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>,
	qemu-arm@nongnu.org, qemu-devel@nongnu.org
Subject: Re: [PATCH v2 5/8] hw/arm/virt: Fix devicetree warnings about the GPIO node
Date: Tue, 29 Nov 2022 14:55:48 -0600	[thread overview]
Message-ID: <CAL_JsqK+NngZMheR7zR2oTVmgNFKKUhZtOAys=NmPQK_FdSq_A@mail.gmail.com> (raw)
In-Reply-To: <CAFEAcA9EqYi0LdXtz84_-8r1L3DUNWdnNL4LTHrm0n4cub4ejQ@mail.gmail.com>

On Tue, Sep 27, 2022 at 6:25 AM Peter Maydell <peter.maydell@linaro.org> wrote:
>
> On Tue, 27 Sept 2022 at 11:12, Jean-Philippe Brucker
> <jean-philippe@linaro.org> wrote:
> >
> > Since the pl061 device can be used as interrupt controller, its node
> > should contain "interrupt-controller" and "#interrupt-cells" properties.
>
> It *can* be, but this PL061 is *not* an interrupt controller.
> I don't see any reason why we should claim so in the DT.

Taking another look, it is an interrupt controller. The GPIOs are
connected to the 'gpio-keys' node which is interrupt based (there's a
polled version too). That binding happens to be pretty lax and allows
the GPIO to be specified either with 'gpios' or 'interrupts' property.
The Linux PL061 driver happens to work only because it always
registers an interrupt controller regardless of having
"interrupt-controller" and "#interrupt-cells" properties or not.

Rob