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

Sergei Shtylyov sshtylyov at ru.mvista.com
Tue Mar 25 01:09:31 EST 2008


Grant Likely wrote:

>> > 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.

    Probably I misunderstood you: does it give the same result as offset 11?

> reg-offset seems to be a better description of the hardware to me.

    Have you considered using the existing "big-endian" property?

> Cheers,
> g.

WBR, Sergei




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