Re: Status of arch/arm in linux-next

[Jamie Lokier <jamie@shareable.org>]

Arnd Bergmann wrote:
> On Thursday 21 April 2011, Nicolas Pitre wrote:
> > > if there's commonality between some of the ARM arch drivers, why can't
> > > there be a arch/arm/cpufreq/ dir for the shared code, and do everything there ?
> > 
> > Because usually there isn't.  "ARM" is just a CPU architecture, not a 
> > system architecture.  Everything around the core is different from one 
> > vendor to the next.  And when commonality exists it is much easier to 
> > deal with if it is close together.
> 
> Exactly. To make matters worse, we are starting to see a number of vendors
> that use multiple CPU architectures with the same I/O devices (e.g. Renesas,
> Freescale, Xilinx, TI, ...). Not sure if any of these use the same cpufreq
> register on more than one architecture, but it's quite likely to happen
> at some point.

Can't comment on in-tree SoCs, but out of tree (they use Linux but
don't submit anything upstream as far as I can tell), Sigma Designs
use ARM & MIPS CPU architectures, with the clock/timing registers, irq
registers and more or less everything else being the same among them.

-- Jamie