Re: [PATCH 4/7] gpiolib: implement dev_gpiochip_{add,remove} calls

From: Anton Vorontsov
Date: Wed Oct 22 2008 - 06:36:51 EST


On Tue, Oct 21, 2008 at 09:22:48PM -0700, David Brownell wrote:
> On Tuesday 21 October 2008, Benjamin Herrenschmidt wrote:
> > The notifier can be registered before the devices, though it's a little
> > bit fishy and fragile.
> >
> > Easier I suppose to just have OF specific hooks in the bus code.
>
> Like what I suggested: "chip-aware OF glue drivers". The relevant
> bus code being the "of_platform_bus_type" infrastructure.
>
> Example: instead of Anton's patch #6 modifying the existing pca953x
> driver, an of_pca953x driver that knows how to poke around in the OF
> device attributes to (a) create the pca953x_platform_data, (b) call
> i2c_register_board_info() to make that available later, and then
> finally (c) vanish, since it's not needed any longer.

Heh. You tell me my first approach:

http://ozlabs.org/pipermail/linuxppc-dev/2008-May/056730.html (mmc_spi)

The OF people didn't like the patch which was used to support this
approach:
http://ozlabs.org/pipermail/linuxppc-dev/2008-May/056728.html


The board info has another problem though. We can't remove it, thus
we can't implement module_exit() for the 'OF glue'.

--
Anton Vorontsov
email: cbouatmailru@xxxxxxxxx
irc://irc.freenode.net/bd2
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