RE: Problems with serial ports

RE: Problems with serial ports

[Kim Jørgensen]

>> Linux runs fine on the board using smc1 as console, but I can't receive
or
>> transmit anything on smc2 and scc2.
>
>The SCC2 is used for Ethernet, and SMC2 is probably reserved for the
>Embedded Planet TDM audio codec.  If you don't use Ethernet, you can
>enable SCC2 for serial use.  You have to manually edit the
>arch/ppc/8xx_io/uart.c port table.

I did that, I added scc2 to rs_table in uart.c and the kernel seams to find
all the
serial ports:

CPM UART driver version 0.03
ttyS00 at 0x0280 is a SMC
ttyS01 at 0x0380 is a SMC
ttyS02 at 0x0100 is a SCC

>  I am working on a configurable
>version, just haven't found anything terribly fool-proof yet.  I also
>have a very different new driver I am testing for the uart.

Is the new driver available?


I tried to use scc2 as console under startup and smc1 as console by the
kernel. (I just changed serial_init to serial_scc_init in head.S)
This works ok, I get the startup messages on scc2 and the kernel messages
and bash prompt on smc1.
Now I can transmit and receive data on scc2 (ttyS2), but still not on smc2.
It seams like scc2 and smc1 is not initialised properly by uart.c.
Can anyone tell me what is wrong?

Kim Jorgensen


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Re: Problems with serial ports

[Dan Malek]

Kim Jørgensen wrote:

> Is the new driver available?

No. It's kind of low on the list of other problems to solve at
the moment.

> I tried to use scc2 as console under startup and smc1 as console by the
> kernel. (I just changed serial_init to serial_scc_init in head.S)

That's only (or less than :-) half of the change.  That is only used
by the Linux bootstrap when requesting command line information and
providing loading status.

> This works ok, I get the startup messages on scc2 and the kernel messages
> and bash prompt on smc1.

That's because I don't yet have the kernel driver part done yet.


	-- Dan

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Re: Problems with serial ports

[Magnus Damm]

Dan Malek wrote:
>
> Kim Jørgensen wrote:
>
> > Is the new driver available?
>
> No. It's kind of low on the list of other problems to solve at
> the moment.

I am working on a new serial driver with support for SCCs with modem control.

Have a nice weekend /

Magnus

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Problems with serial ports

[Kim Jørgensen]

Hi.

I got a custom MPC823 board with 3 serial ports (smc1, smc2 and scc2), and a
2.2.13 kernel form mvista.

Linux runs fine on the board using smc1 as console, but I can't receive or
transmit anything on smc2 and scc2.

I am using the program miniterm to setup and test these ports; I have used
this program on my RH i686 machine without any problems.

I have used scc2 as console too, without any problem. But I still can't use
smc1 and smc2. I look like an initialisation problem to me. Can anyone help
with this?


Btw. There is a problem in m8xx_cpm_setbrg in commproc.c. I can't set any
serial port to run any lower than 1200 baud. This is caused by
BRG_UART_CLK/rate (clock divider) getting larger than 4096, which is the
maximum (at least on a mpc823).
I solved the problem like this:

#define BRG_INT_CLK		(((bd_t *)res)->bi_intfreq * 1000000)
#define BRG_UART_CLK		(BRG_INT_CLK/16)
#define BRG_UART_CLK_DIV16	(BRG_UART_CLK/16)

void
m8xx_cpm_setbrg(uint brg, uint rate)
{
	volatile uint	*bp;

	/* This is good enough to get SMCs running.....
	*/
	bp = (uint *)&cpmp->cp_brgc1;
	bp += brg;
	if((BRG_UART_CLK / rate) < 4096)
	    *bp = ((BRG_UART_CLK / rate) << 1) | CPM_BRG_EN;
	else
	    *bp = ((BRG_UART_CLK_DIV16 / rate) << 1) | CPM_BRG_EN |
CPM_BRG_DIV16;
}

Kim Jorgensen


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Re: Problems with serial ports

[Dan Malek]

Kim Jørgensen wrote:

> Linux runs fine on the board using smc1 as console, but I can't receive or
> transmit anything on smc2 and scc2.

The SCC2 is used for Ethernet, and SMC2 is probably reserved for the
Embedded Planet TDM audio codec.  If you don't use Ethernet, you can
enable SCC2 for serial use.  You have to manually edit the
arch/ppc/8xx_io/uart.c port table.  I am working on a configurable
version, just haven't found anything terribly fool-proof yet.  I also
have a very different new driver I am testing for the uart.


> Btw. There is a problem in m8xx_cpm_setbrg in commproc.c. I can't set any
> serial port to run any lower than 1200 baud.

OK......You are the first to ask :-).  I'll check this into the code.



	-- Dan

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