Date: Tue, 20 Nov 2012 09:07:56 +0200
From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jean Delvare <khali@linux-fr.org>, "Rafael J. Wysocki" <rjw@sisk.pl>,
        ben-linux@fluff.org, w.sang@pengutronix.de,
        linux-kernel@vger.kernel.org, lenb@kernel.org,
        rafael.j.wysocki@intel.com, broonie@opensource.wolfsonmicro.com,
        grant.likely@secretlab.ca, linus.walleij@linaro.org,
        mathias.nyman@linux.intel.com, linux-acpi@vger.kernel.org
Subject: Re: [PATCH v2 3/3 UPDATED] i2c / ACPI: add ACPI enumeration support
Message-ID: <20121120070756.GM17774@intel.com>
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On Mon, Nov 19, 2012 at 03:49:25PM -0700, Bjorn Helgaas wrote:
> I think the benefit here is that you can merely point
> .acpi_match_table at an acpi_device_id[] table, then use
> platform_get_resource() as a generic way to get resources, whether the
> platform device came from OF, ACPI, etc.  The alternative would be to
> add, e.g., a PNP driver with a .probe() method that uses
> pnp_get_resource().  That's not very much code, but it is more, even
> if the .probe() method just calls a device registration function
> that's shared across bus types.
> 
> That benefit seems like a great thing, and my question then is why
> wouldn't we just do it across the board and make platform devices for
> *all* ACPI devices without having the I2C and SPI special cases?

That wouldn't be any better than having a PNP or ACPI device. We must still
create the corresponding I2C or SPI device in order to have a driver that
can plug into I2C or SPI core.
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