MPC8xx: Using SCM/SCC and standard 16C550 Uarts together...

Yuli Barcohen yuli at
Wed Jan 12 23:18:10 EST 2005

>>>>> David Jander writes:

    David> On Wednesday 12 January 2005 10:59, Demke Torsten-atd012
    David> wrote:

    Demke> I dont know exactly the state of the DENX kernel, but in the
    Demke> standard kernel the 8xx UART driver and the 16550 driver are
    Demke> using the same device numbers (TTY_MAJOR) and device names
    Demke> (/dev/ttySx).  You have to change one of them.

    David> You are right! What now? I cannot go around and change
    David> TTY_MAJOR!  Is it true then, that you normally cannot have a
    David> mix of non-16550 uarts and 16550 uarts on the same system,
    David> without doing nonstandard things with major numbers?

We've got such a mix but we use completely different MPC8xx support
infrastructure. Our SCC/SMC UART driver takes care of possible external
UARTs (it uses the same major number but configurable minor).

    David> Should maybe arch/ppc/8xx_io/uart.c use another major number?

Then you'll have to change all applications using standard device names

 Yuli Barcohen       | Phone +972-9-765-1788 |  Software Project Leader
 yuli at | Fax   +972-9-765-7494 | Arabella Software, Israel

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