Re: [PATCH] booting-without-of: add Xilinx uart 16550.

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

On Fri, Feb 15, 2008 at 6:40 AM, Pavel Kiryukhin
<pkiryukhin@ru.mvista.com> wrote:
> Add uart 16550 properties description to Xilinx portion of booting-without-of.txt
>
>  Signed-off-by: Pavel Kiryukhin <pkiryukhin@ru.mvista.com>
>  ---
>   Documentation/powerpc/booting-without-of.txt |   16 ++++++++++++++--
>   1 files changed, 14 insertions(+), 2 deletions(-)
>
>  diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt
>  index 7b4e8a7..dd77bbc 100644
>  --- a/Documentation/powerpc/booting-without-of.txt
>  +++ b/Documentation/powerpc/booting-without-of.txt
>  @@ -2575,10 +2575,22 @@ platforms are moved over to use the flattened-device-tree model.
>
>        Xilinx uartlite devices are simple fixed speed serial ports.
>
>  -      Requred properties:
>  +      Required properties:
>         - current-speed : Baud rate of uartlite
>
>  -      v) Xilinx hwicap
>  +      v) Xilinx Uart 16550
>  +
>  +      Xilinx uart 16550 device registers are compatible with all standard 16540
>  +      and 16550 UARTs.

Not strictly true; the xilinx uart is *almost* compatible with the
ns16550.  The same driver can be made to work, but it is not register
level compatible so we cannot claim compatible="ns16550".  We need a
new compatible property for 16550 like devices with a reg shift and
offset.  Instead of attempting to come up with a generic description
of this, I recommend just naming it after the actual device instance;
something like compatible="xlnx,opb-uart16550";

Cheers,
g.