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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Fri, 22 Jan 2021 19:21:44 +0100
Message-ID: <CAJZ5v0gtS9P5Hg1JJJ-KPEZ-qSfnMyf4vaCcZ=9HOijky2hc+Q@mail.gmail.com>
Subject: Re: [net-next PATCH v4 09/15] device property: Introduce fwnode_get_id()
To:     Andy Shevchenko <andy.shevchenko@gmail.com>
Cc:     Calvin Johnson <calvin.johnson@oss.nxp.com>,
        Grant Likely <grant.likely@arm.com>,
        Jeremy Linton <jeremy.linton@arm.com>,
        Andrew Lunn <andrew@lunn.ch>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Russell King - ARM Linux admin <linux@armlinux.org.uk>,
        Cristi Sovaiala <cristian.sovaiala@nxp.com>,
        Florin Laurentiu Chiculita <florinlaurentiu.chiculita@nxp.com>,
        Ioana Ciornei <ioana.ciornei@nxp.com>,
        Madalin Bucur <madalin.bucur@oss.nxp.com>,
        Heikki Krogerus <heikki.krogerus@linux.intel.com>,
        Marcin Wojtas <mw@semihalf.com>,
        Pieter Jansen Van Vuuren <pieter.jansenvv@bamboosystems.io>,
        Jon <jon@solid-run.com>, Saravana Kannan <saravanak@google.com>,
        Randy Dunlap <rdunlap@infradead.org>,
        "linux.cj" <linux.cj@gmail.com>,
        Diana Madalina Craciun <diana.craciun@nxp.com>,
        ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
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On Fri, Jan 22, 2021 at 7:11 PM Rafael J. Wysocki <rafael@kernel.org> wrote:
>
> On Fri, Jan 22, 2021 at 6:12 PM Andy Shevchenko
> <andy.shevchenko@gmail.com> wrote:
> >
> > On Fri, Jan 22, 2021 at 05:40:41PM +0100, Rafael J. Wysocki wrote:
> > > On Fri, Jan 22, 2021 at 4:46 PM Calvin Johnson
> > > <calvin.johnson@oss.nxp.com> wrote:
> > > >
> > > > Using fwnode_get_id(), get the reg property value for DT node
> > > > or get the _ADR object value for ACPI node.
> > >
> > > So I'm not really sure if this is going to be generically useful.
> > >
> > > First of all, the meaning of the _ADR return value is specific to a
> > > given bus type (e.g. the PCI encoding of it is different from the I2C
> > > encoding of it) and it just happens to be matching the definition of
> > > the "reg" property for this particular binding.
> >
> > > IOW, not everyone may expect the "reg" property and the _ADR return
> > > value to have the same encoding and belong to the same set of values,
> >
> > I have counted three or even four attempts to open code exact this scenario
> > in the past couple of years. And I have no idea where to put a common base for
> > them so they will not duplicate this in each case.
>
> In that case it makes sense to have it in the core, but calling the
> _ADR return value an "id" generically is a stretch to put it lightly.
>
> It may be better to call the function something like
> fwnode_get_local_bus_id()

Or fwnode_get_local_address() for that matter.