SCC3 UART for MPC850

SCC3 UART for MPC850

[Donald MacArthur]

I am currently working with an embedded planet LICCE MPC850 Credit card
board with the associated MPC860 Timesys Linux Kernel.  I would like to use
as many SCC and SMC channels for UARTs as possible.  I have successfully
enabled SMC1, SMC2, and SCC2 for UART but SCC3 does not work.  Normally for
the UART channels the TX lines go high when the kernel boots but the SCC3 Tx
channel does not.  Does anyone know of modifications required for the kernel
to get SCC3 to work as a UART or were possible conflicts might arise?

Thank You
Don MacArthur
dmacarth@ufl.edu


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Re: SCC3 UART for MPC850

[Wolfgang Denk]

In message <NDBBIHDFKLJKGJJGMFJOIEANCHAA.dmacarth@ufl.edu> you wrote:
>
> I am currently working with an embedded planet LICCE MPC850 Credit card
> board with the associated MPC860 Timesys Linux Kernel.  I would like to use
> as many SCC and SMC channels for UARTs as possible.  I have successfully
> enabled SMC1, SMC2, and SCC2 for UART but SCC3 does not work.  Normally for
> the UART channels the TX lines go high when the kernel boots but the SCC3 Tx
> channel does not.  Does anyone know of modifications required for the kernel
> to get SCC3 to work as a UART or were possible conflicts might arise?

See the uart.c driver in the kernel source tree on our CVS server for
support of serial ports on all SMC / SCC ports.

Sorry, this is one of our patches that never  was  accepted  for  the
official source trees (also including hardware flow control).


Best regards,

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
You have the capacity to learn from  mistakes.  You'll  learn  a  lot
today.

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RE: SCC3 UART for MPC850

[Steven Blakeslee]

Are you sure that particular variant of the 850 processor has an SCC3?

-----Original Message-----
From: Donald MacArthur [mailto:dmacarth@ufl.edu]
Sent: Monday, March 03, 2003 8:53 AM
To: linuxppc-embedded@lists.linuxppc.org
Subject: SCC3 UART for MPC850



I am currently working with an embedded planet LICCE MPC850 Credit card
board with the associated MPC860 Timesys Linux Kernel.  I would like to use
as many SCC and SMC channels for UARTs as possible.  I have successfully
enabled SMC1, SMC2, and SCC2 for UART but SCC3 does not work.  Normally for
the UART channels the TX lines go high when the kernel boots but the SCC3 Tx
channel does not.  Does anyone know of modifications required for the kernel
to get SCC3 to work as a UART or were possible conflicts might arise?

Thank You
Don MacArthur
dmacarth@ufl.edu


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Re: SCC3 UART for MPC850

[Dan Malek]

Donald MacArthur wrote:

> I am currently working with an embedded planet LICCE MPC850 Credit card
> board ...

> ...Does anyone know of modifications required for the kernel
> to get SCC3 to work as a UART or were possible conflicts might arise?

There are several things that may need attention.  First, ensure the
version of the 850 you have actually has the SCC3 port.  Second, as
in many cases, the SCC3 pins are multiplexed with other uses.  In this
case you have to program the I/O so they are used for SCC3 instead of
SPI and other functions.  Third, if you are using one of the matching
Embedded Planet I/O cards, ensure the board control register has been
written to enable/route the driver.  If you are using the Embedded Planet
I/O card, check the documentation for the specific card to ensure you
can enable all of the serial ports.  In some cases not all combinations
are supported.


	-- Dan


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Re: SCC3 UART for MPC850

[Wolfgang Denk]

In message <20030303234618.GA12721@ip68-0-152-218.tc.ph.cox.net> you wrote:
>
> > Sorry, this is one of our patches that never  was  accepted  for  the
> > official source trees (also including hardware flow control).
>
> ... because you never split things out into logical chunks which make
> life easier on people trying to understand what changed and why.  Our
> last merge went well I thought, and I'm up for another round if you are.

It would be too much trouble to separate the  hardware  flow  control
stuff  from the other port configuration options. I feel it should be
sufficient to have a set of changes local to one single source file.

You say it is not sufficent. OK. You are the maintainer, I ain't.

It's your decision, and I won't discuss it.


Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
"Most people would like to be delivered  from  temptation  but  would
like it to keep in touch."                             - Robert Orben

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Re: SCC3 UART for MPC850

[Tom Rini]

On Tue, Mar 04, 2003 at 01:03:30AM +0100, Wolfgang Denk wrote:
>
> In message <20030303234618.GA12721@ip68-0-152-218.tc.ph.cox.net> you wrote:
> >
> > > Sorry, this is one of our patches that never  was  accepted  for  the
> > > official source trees (also including hardware flow control).
> >
> > ... because you never split things out into logical chunks which make
> > life easier on people trying to understand what changed and why.  Our
> > last merge went well I thought, and I'm up for another round if you are.
>
> It would be too much trouble to separate the  hardware  flow  control
> stuff  from the other port configuration options. I feel it should be
> sufficient to have a set of changes local to one single source file.

If you're referring to the very configurable SCC portion, as far as I
know, no one, including yourself has made a verion which satisifes all
of the people all of the time, which is why Dan hasn't approved any of
the patches to do that.  But maybe the 2.5 config language will
allow someone to write it in a manner which lets everyone do what they
want..

But, it's been a while, so if it's not too much trouble, can you send it
out again?

> You say it is not sufficent. OK. You are the maintainer, I ain't.

Dan Malek is really, I just try and help him when I can. :)

--
Tom Rini
http://gate.crashing.org/~trini/

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