[PATCH] ARM/sp810: introduce API to change system mode

[Russell King - ARM Linux]

On Mon, Feb 27, 2012 at 04:29:58PM +0100, Linus Walleij wrote:
> On Mon, Feb 27, 2012 at 11:55 AM, Russell King - ARM Linux
> <linux at arm.linux.org.uk> wrote:
> > On Mon, Feb 27, 2012 at 11:38:14AM +0100, Linus Walleij wrote:
> >> Maybe I'm delusional but I think this could help centralizing the use
> >> of the SP* cells, since they're obviously used in both SPEAr and
> >> versatile express.
> >
> > They can be used in any PrimeXsys based system, and I don't see that
> > there's anything which guarantees having both a SP810 and SP804
> > together.
> >
> > There are platforms which have SP804 without SP810 - Integrator CP
> > and bcmring seem to fall into that category.
> 
> I was more thinking the other way around - I think that all systems
> with an SP810 also have an SP804.
> 
> I'm led to thinking this because of these registers:
> 
> #define SCCTRL_TIMEREN0SEL_REFCLK       (0 << 15)
> #define SCCTRL_TIMEREN0SEL_TIMCLK       (1 << 15)
> #define SCCTRL_TIMEREN1SEL_REFCLK       (0 << 17)
> #define SCCTRL_TIMEREN1SEL_TIMCLK       (1 << 17)
> 
> TIMER0 and TIMER1 seems to indicate TIMER0 and TIMER1
> of the SP804 block.

Except... there's four timers, and we may not be necessarily using timer 0
and 1.  So, you'd need to know independently which are the two timers
you're using.