Re: [PATCH] Re: [PATCH 4/4 v2] [RFC] UIO: generic platform driver

[Russell King - ARM Linux <linux@arm.linux.org.uk>]

On Mon, Apr 14, 2008 at 09:48:58AM +0200, Uwe Kleine-König wrote:
> Hello,
> 
> > > > > > But what about this:
> > > > > > 
> > > > > > ERROR: "clk_get" [drivers/uio/uio_pdrv.ko] undefined!
> > > > > > ERROR: "clk_enable" [drivers/uio/uio_pdrv.ko] undefined!
> > > > > > ERROR: "clk_disable" [drivers/uio/uio_pdrv.ko] undefined!
> > > > > > ERROR: "clk_put" [drivers/uio/uio_pdrv.ko] undefined!
> > > > > > 
> > > > > > Do you have any extra patches applied?
> > > > > Yes I have, but nothing special.  This is part of a generic API defined
> > > > > in include/linux/clk.h.  One of it's use it to abstract away some
> > > > > platform dependencies.  There are several architectures that define
> > > > > it[1].
> > > > 
> > > > I know. Unfortunately, I tested on x86_64, and it doesn't compile.
> > > > If it's depending on something, then this dependency should be added in
> > > > Kconfig. If it can be selected in the configuration, I expect it to
> > > > compile (and work).
> > > Maybe adding a dummy implementation that is compiled for machines that
> > > don't provide a native one.  Currently there is no cpp symbol that tells
> > > if an machine supports the API.
> > > 
> > > @Russell: Do you have an opinion regarding this!?
> > 
> > Only that the kernels Kconfig is turning into a real complicated mess
> > of dependencies IMHO.
> > 
> > We could add a HAVE_CLK and add that to the dependency of all the drivers
> > which use linux/clk.h.  The problem will be finding all those drivers and
> > their corresponding Kconfig entries.
> > 
> > My feeling is that we're just going to end up creating another Kconfig
> > symbol which folk half-heartedly use.
>
> I don't like that either.  What do you think about the patch below?
> It doesn't introduce a new symbol that needs much care and attention.
> This way the clk API is available on all configurations provided that 
> CONFIG_DUMMY_CLK is set correctly.  If CONFIG_DUMMY_CLK is set wrong it
> should result in a compile error.  Either because there are two
> implementations of clk_get or none.

Hang on.  I'm lost.  What are we talking about here?  I thought the
thread was about the one liner patch for UIO to arch/arm/Kconfi
(which still hasn't hit the patch system so is still on target for
being missed...)

What's this drivers/uio/uio_pdrv.ko module, and why doesn't it appear
in the LKML archive of this thread?