[PATCH 0/7] share sa1100 rtc driver to arch-mmp

[Russell King - ARM Linux]

On Thu, Feb 23, 2012 at 06:22:23PM +0800, Haojian Zhuang wrote:
> On Thu, Feb 23, 2012 at 6:00 PM, Russell King - ARM Linux
> <linux at arm.linux.org.uk> wrote:
> > On Thu, Feb 23, 2012 at 05:45:20PM +0800, Haojian Zhuang wrote:
> >> On Thu, Feb 23, 2012 at 4:52 PM, Robert Jarzmik <robert.jarzmik at free.fr> wrote:
> >> > The behaviour should be as before, the config should be able to choose between
> >> > rtc-pxa and rtc-sa1100 for a pxa27x based board. For sharpsl_pm, I suppose the
> >> > rtc-sa1100 will be chosen in the .config, and for mioa701, it will be
> >> > rtc-pxa.
> >> >
> >> > Just to clear, I'm against removing "resources, clock" from pxa27x platform code
> >> > which would break rtc-pxa driver on pxa27x. Now I don't care if you're talking
> >> > about changing some "defconfigs".
> >> >
> >>
> >> How about to move the rtc-sa1100 or rtc-pxa device register from
> >> pxa27x.c to board file? Then we'll be both happy.
> >
> > How about stopping thinking about "one or other" and start thinking "both" ?
> > The RTC library can and does cope with more than one RTC, and each RTC is
> > exposed uniquely to userspace.  So there shouldn't be any problem in keeping
> > both around, or even registering both together.
> >
> > You just have to make sure you don't use both of them together as their
> > open functions will want to claim the same IRQ.  That's not really a
> > problem because that should provide exclusivity between the two.
> 
> Resource is bind with platform device. We'll meet resource conflict if
> we register them both.

Ok, in that case we need patch 3 split up such that we can move forward
and get some of the build errors fixed.

That probably means that the first half of patch 3 should be providing the
IRQs and only the IRQs to the driver, and the driver making use of that
information.  Nothing more than that - not even the differing register
offsets.

The next stage would be to introduce the different device names, and use
that to chose the different register layouts - but still using a hard coded
base address.  That will involve adding a new define for this to both
arch/arm/mach-sa1100/include/mach/SA-1100.h and
arch/arm/mach-pxa/include/mach/regs-rtc.h.  At the same time, this patch
should move the register definitions from those headers into the sa1100 RTC
driver, and get rid of the virtual address definitions for these registers.

The clocking issues can also be sorted out as well without solving the base
address issue - and that gets most of this patch set ready for merging
without causing Robert any problems.

I would like to see this ASAP so that the current build regression with
PXA can be fixed.