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

Stephen Neuendorffer stephen.neuendorffer at xilinx.com
Sat Feb 16 04:46:28 EST 2008



> -----Original Message-----
> From: Pavel Kiryukhin [mailto:pkiryukhin at ru.mvista.com]
> Sent: Friday, February 15, 2008 9:41 AM
> To: Stephen Neuendorffer
> Cc: linuxppc-dev at ozlabs.org
> Subject: Re: [PATCH] booting-without-of: add Xilinx uart 16550.
> 
> Stephen Neuendorffer wrote:
> >> +       - reg-shift : registers offset shift (standard uart_port
> > field).
> >> +         Property is optional if regshift is zero.
> >
> > I was hoping to get an idea of what is required here, or when I
might
> > use it?
> >
> > It looks like the ARCH=ppc code instantiates this with a reg-shift
of
> > 2...  Is this the expected value?
> 
> Yes, reg-shift = 2 should be set for Xilinx 16550 uart.
> Should I add this to patch?

Yes, please!
 
> BTW regshift=2 is hardcoded for uartlite.
> 
> > When would it be not zero? or not
> > two?
> Sorry, it seems I don't follow here.

I think all that needs to get added is 'For the Xilinx uart 16550 cores,
reg-shift must be set to 2'

Steve





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