Re: [net-next PATCH v4 09/15] device property: Introduce fwnode_get_id()

From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: "Rafael J. Wysocki" <rafael@kernel.org>
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>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	netdev <netdev@vger.kernel.org>,
	Laurentiu Tudor <laurentiu.tudor@nxp.com>,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>,
	Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Subject: Re: [net-next PATCH v4 09/15] device property: Introduce fwnode_get_id()
Date: Fri, 22 Jan 2021 19:13:14 +0200	[thread overview]
Message-ID: <YAsHqu/nW3zU/JgO@smile.fi.intel.com> (raw)
In-Reply-To: <CAJZ5v0gzdi08fwf0e3NyP1WzuSBk47J5OT5DW_aaUHn_9icfag@mail.gmail.com>

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.

> so maybe put this function somewhere closer to the code that's going
> to use it, because it seems to be kind of specific to this particular
> use case?

-- 
With Best Regards,
Andy Shevchenko