[U-Boot] RFC: How use same interface between arm926ejs/at91 and arm920t/at91

[Andreas Bießmann]

Dear Reinhard Meyer,

I try to remove deprecated at91rm9200_usart driver for 2011.06 release
(and switch to atmel_usart for at91rm9200 devices). This require the
get_usart_clk_rate() which in turn requires get_mck_clk_rate()
interface. This interface is currently implemented in
a/a/c/arm926ejs/at91/clock.c and requires at91_clock_init() in the
same file to run first. This implementation currently in u-boot is
already prepared for at91rm9200, I could just include these files from
arm926ejs in my arm920t build files and can use the interface for
atmel_usart driver (my current test case copies these files to
arm920t).

So my question is how should we handle this?

I see three options here:
 a) include necessary files from arm926ejs in am920t build (maybe with
some extra arm920t related defines in ar926ejs)
 b) copy current arm926ejs files to arm920t (and maybe clean them up
to only include the relevant stuff)
 c) build an a/a/lib/at91, copy the common part to that 'at91 library'
and implement the architecture specific part in arm920t and arm926ejs
respectively.

regards

Andreas Bießmann