SMC as UART problem on mpc8xx

Vitaly Bordug vbordug at ru.mvista.com
Sat Feb 3 01:54:55 EST 2007


On 02 Feb 2007 11:51:01 +0100 (CET)
Ladislav Klenovic <poseidon21 at post.sk> wrote:

> > On 01 Feb 2007 17:10:31 +0100 (CET)
> > a b  wrote:
> > 
> > > Hi,
> > > I have mpc8xx where I would like the following configuration:
> > >  - SCC1 as system console (works fine) 
> > >  - SMC1-2 as UART (doesn\\\'t work)
> > > 
> > > I use linux 2.6.16.20 with backward patch from linux-2.6.19.2 for SMCs. My only problem is 
> > > that even I can see cpm_uart registered for IRQ 20 (for SMC1) I never get interrupt even
> > > I do e.g. \\\"echo 123 > /dev/ttyCPM\\\". 
> > > 
> > > here is a short extract from /proc/interrupts:
> > >  20:          0   CPM       Edge      cpm_uart  <--SMC1
> > >  21:       7546   CPM       Edge      SPI
> > >  46:         20   CPM       Edge      cpm_uart  <-- SCC1 (console)
> > > 
> > > here is a short extract from /proc/tty/driver/ttyCPM:
> > > serinfo:1.0 driver revision:
> > > 0: uart:CPM UART mmio:0xFFF00A80 irq:20 tx:14 rx:0 RTS|CTS|DTR|DSR|CD
> > > 1: uart:CPM UART mmio:0xFFF00A90 irq:19 tx:0 rx:0 CTS|DSR|CD
> > > 2: uart:CPM UART mmio:0xFFF00A00 irq:46 tx:3038 rx:46 RTS|CTS|DTR|DSR|CD
> > > 
> > > Can anybody help me to get SMCs working?
> > > 
> > > 
> > Check IO ports? IIRC, in 8xx some SoC devices could not work simultaneously because they 
> > share some GPIO pins. In any case, if something does not function with CPM UART, IOports stuff is the first thing to check.
> > 
> > -- 
> > Sincerely, 
> > Vitaly
> > 
> 
> Hi,
> thnx for hint, you were right, problem was in I/O port configuration. 
> I am a bit wondered why is B port for mpc8xx not configured in 2.16.19.2. Or is it  
> configured somewhere else? I especially miss this part of code in cpm_uart_cpm1.c:
> 
> void smc1_lineif(struct uart_cpm_port *pinfo){
> ...
> #elif defined (CONFIG_MPC86XADS)
>        if (!pinfo->is_portb) {
>                 cp->cp_pbpar |= iobits;
>                 cp->cp_pbdir &= ~iobits;
>                 cp->cp_pbodr &= ~iobits;
>         } else {
>                 ((immap_t *)IMAP_ADDR)->im_ioport.iop_papar |= iobits;
>                 ((immap_t *)IMAP_ADDR)->im_ioport.iop_padir &= ~iobits;
>                 ((immap_t *)IMAP_ADDR)->im_ioport.iop_paodr &= ~iobits;
>         }
> #endif
> ...
> }
> 
Oh well, the preferred way is not to bloat drivers/ space with code snippets that are clearly 
board specific. There are hooks to set up IO space in BSP code already, it just has to have proper pinfo 
set up - mpc86xads and mpc885ads work that way. Yet I haven't checked ppc/ stuff for a while, being concentrated on arch/powerpc...


-- 
Sincerely, 
Vitaly



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