Re: [PATCH 2/3] [POWERPC] Xilinx: of_serial support for Xilinx uart 16550.

["Grant Likely" <grant.likely@secretlab.ca>]

On Fri, Mar 21, 2008 at 3:21 AM, Paul Mackerras <paulus@samba.org> wrote:
> Grant Likely writes:
>
>  > Personally, I'm not fond of this approach.  There is already some
>  > traction to using the reg-shift property to specify spacing, and I
>  > think it would be appropriate to also define a reg-offset property to
>  > handle the +3 offset and then let the xilinx 16550 nodes use those.
>
>  Why do we need a reg-offset property when we can just add the offset
>  to the appropriate word(s) in the reg property?

Primarily because the device creates 32 byte registers starting at 0;
but they are also big-endian byte accessible so a byte read at offset
8 also works.  reg-offset seems to be a better description of the
hardware to me.

Cheers,
g.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.