State of 16550 driver in libchip

Joel Sherrill joel.sherrill at
Tue Apr 3 18:53:30 UTC 2001

peter.o.mueller at wrote:
> We have a 16552 chip on our board. I saw an 16550 driver in the libchip
> directory. Can anyone tell me the state of this driver. The readme mentioned that
> poll should work, but irq operation was not really tested. The
> rtems_termios_callbacks struct is not the one used in e.g. gen68360, so I assume the
> driver was not in use for some time.
> What is the reference bsp for hooking serial drivers into rtems (gen68360)?
> At the moment we do it like this:
> rtems_io_register_name("/dev/ttyS1", major, 0);
> rtems_io_register_name("/dev/ttyS2", major, 1);
> rtems_termios_open(major, 0, 0 /* arg */ &opllCallbacks);
> rtems_termios_open(major, 1, 0 /* arg */ &opllCallbacks);
> Is this the proposed way?

Not really.  When using libchip drivers, all you do is provide
information and possibly some register access routines.  I would
recommend looking at the powerpc/dmv177/console for an example 
configuration.  It illustrates the power of this approach.  That board
has a mixture of serial devices (68681 clone and Z8530) with each
chip being optional.

> Is there a list what major numbers are currently in use?

They are whatever you configure in the driver table.

> Peter
> --
> GMX - Die Kommunikationsplattform im Internet.

Joel Sherrill, Ph.D.             Director of Research & Development
joel at                 On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
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