[U-Boot] How can I make a second serial port on a motorola 8248 Chip known to Linux.

[Scott Wood]

On Tue, Aug 25, 2009 at 08:37:11AM -0700, AGKohler wrote:
> 
> Hello,
> 
> I am working with a mpc8260ads(actually QUICC 8248 processor) based board. 
> There are two hardware rs-232 ports available. 
> I can switch the console between the two by switching the CONFIG_CONS_INDEX 
> configuration variable between 1 and 4.
> I would like to have both ports in service, when Linux comes up. One as the
> console and the second to communicate with(i.e. acquire data from) a third
> party rs-232 device. Eventually, the third party device may be a telephone
> modem. Can anyone explain how to accomplish this, and if not, what
> constraints are blocking the accomplishment of my requirements. Any
> suggestions will be appreciated.

This isn't a U-Boot issue, except insofar as U-Boot passes a device tree
to Linux (assuming it does even that -- you don't mention which kernel or
u-boot version you're using).

If your device tree contains both serial ports, then Linux should be able
to use them both.  If it doesn't work, make sure all the pins are
configured correctly, typically by Linux platform code for your board
(though ideally U-Boot should set them up as well).

-Scott