[U-Boot-Users] AT91 Header File Clarification

[Stelian Pop]

Le vendredi 04 avril 2008 à 16:32 -0700, Zac Wheeler a écrit :
> On Fri, Apr 4, 2008 at 3:25 PM, Stelian Pop <stelian at popies.net> wrote:
> >
> >  Le vendredi 04 avril 2008 à 13:32 -0700, Zac Wheeler a écrit :
> >
> > > I have a question about the arrangement of include files for the
> >  > at91sam9 family.
> >  >
> >  > Is the intention that asm/arch/at91_xxx.h be applicable for all
> >  > at91sam9 microcontrollers, or should they be broken down into subarch
> >  > folders (e.g. asm/arch/at91sam9261/at91_pmc.h)?
> >
> >  They are supposed to be shareable for all at91sam microcontrollers, in
> >  the same way it's done in Linux.
> 
> So should things like AT91_ECC as defined in at91sam960.h be
> AT91SAM9260_ECC instead or moved to an at91_sys.h file?

No, the idea is to keep the same conventions as the kernel guys. In fact
the header files have been copied from Linux, and are 95% identical to
them (we cannot use the header files provided by Atmel, because there is
too much craft inside, and rewriting a third form of the same headers
seemed to me too error prone).

As for AT91_ECC:

at91cap9.h:#define AT91_ECC     (0xffffe200 - AT91_BASE_SYS)
at91sam9260.h:#define AT91_ECC  (0xffffe800 - AT91_BASE_SYS)
at91sam9263.h:#define AT91_ECC0 (0xffffe000 - AT91_BASE_SYS)
at91sam9263.h:#define AT91_ECC1 (0xffffe600 - AT91_BASE_SYS)
at91sam9rl.h:#define AT91_ECC   (0xffffe800 - AT91_BASE_SYS)

seems to me quite nice this way !

>  It seems
> somewhat dangerous to define an AT91_ in a AT91SAM9260-specific file.

It shouldn't be. All the AT91 platforms have pretty much the same
hardware, so having the same constants means we don't need extra #ifdefs
in the driver code.

Of course, one should take care of including only the header file which
goes with his platform. This is what
include/asm-arm/arch-at91sam9/hardware.h does: based on what
CONFIG_AT91xxxxx is defined, the relevant platform specific header file
is included.

Stelian.
-- 
Stelian Pop <stelian at popies.net>