[U-Boot] [PATCH] ns16550: allow UART address to be set dynamically

[Stephen Warren <swarren@wwwdotorg.org>]

On 12/17/2012 11:39 PM, Wolfgang Denk wrote:
> Dear Stephen,
> 
> In message <50CFA394.40901@wwwdotorg.org> you wrote:
>>
>>> Yes, there are.  But your console port cannot be compred against
>>> dynamically populated and scannable bus interfaces like USB or PCI,
>>> and I think you are aware of that.
>>
>> I honestly don't know why you couldn't have a PCI-based console UART.
> 
> This is actually another question.
> 
> You cannot compare a statically configured UART port (where all
> configuration information you need is the index into the table of
> possible UARTs)

That's not the only piece of information that is required. At least on
Tegra (and I imagine on most SoCs with a pinmux) you need to fully
describe the UART-related pinmux programming, so that the UART signals
actually get routed out of the SoC.

> to a dynamic bus scan where you cannot know in advance
> whether you detect any devices at all, or how many, or which types.

A board could have a PCI UART soldered onto the board, and hence be
physically static and known ahead of time, yet still require (at least
part of) the PCI bus to be correctly probed and programmed.

> It seems Simon, Tom and me mostly agree on what to do.

To be honest, that's not remotely the impression I get.