On Mon, Feb 20, 2006 at 02:37:23PM +0100, Bj?rn ?stby wrote:
> Hello,
> I'm messing with a mpc823e based board trying to enable the SCC3 UART. I'm
> using the 2.4.25 denx linux_ppc kernel and I've got SMC1 for console and SMC2
> up and running but I'm in desperate need of another rs232 port (which is on
> SCC3 on my board).
> Reading quite a lot of old posts on this mailing list got me confused whether
> the SCCx UART support in the kernel is ready to be used on 8xx or if there
> will take a large amount of hacking to get things going (reading the header
> of 8xx_io/uart.c got me wondering even more).
> Current situation is that I have enabled the SCC3 UART in the kernel, set the
> correct CTS, RTS and CD signal options and finally disabled the SPI which (on
> my board at least) can override the UART on the third SCC port. During boot
> up I get the standard output:
>
> >ttyS0 at 0x0280 is on SMC1 using BRG1
> >ttyS1 at 0x0380 is on SMC2 using BRG2
> >ttyS2 at 0x0200 is on SCC3 using BRG3
>
> Writing to ttyS0 and ttyS1 works fine (the result pop up in the receiving
> terminal) but when trying ttyS2 nothing happens. I've checked the Tx signal
> and it appears as if data is sent (the signal gets noisy when starting the
> write procedure). I may also add that restaring the write application causes
> the kernel to hang (for ttyS2 only of course).
>
> I've read some posts saying that Linux don't init other uart ports than the
> console port and that is the potential problem here, but it is unclear if
> this statement is true or not. I can also add to the problem description that
> my SMC2 port works fine for writing, but reading just hangs in the read()
> call. So, can anyone confirm any status on the SMCx and SCCx UART drivers for
> 2.4?
please try the two attached patches. the first one configures each SCC to
one BRG. the second one, makes use always of dpram memory. we're working on a
decent fix.
Marcelo: if you find the first one ok, you may apply it, but don't apply the
second
--
Aristeu
-------------- next part --------------
Index: stable/drivers/serial/cpm_uart/cpm_uart_cpm1.c
===================================================================
--- stable.orig/drivers/serial/cpm_uart/cpm_uart_cpm1.c 2006-02-17
17:11:37.000000000 -0200
+++ stable/drivers/serial/cpm_uart/cpm_uart_cpm1.c 2006-02-17
17:15:57.000000000 -0200
@@ -139,24 +139,31 @@
void scc1_lineif(struct uart_cpm_port *pinfo)
{
/* XXX SCC1: insert port configuration here */
+ cpmp->cp_sicr &= 0xFFFFFFC0;
pinfo->brg = 1;
}
void scc2_lineif(struct uart_cpm_port *pinfo)
{
/* XXX SCC2: insert port configuration here */
+ cpmp->cp_sicr &= 0xFFFFC0FF;
+ cpmp->cp_sicr |= 0x00000900;
pinfo->brg = 2;
}
void scc3_lineif(struct uart_cpm_port *pinfo)
{
/* XXX SCC3: insert port configuration here */
+ cpmp->cp_sicr &= 0xFFC0FFFF;
+ cpmp->cp_sicr |= 0x00140000;
pinfo->brg = 3;
}
void scc4_lineif(struct uart_cpm_port *pinfo)
{
/* XXX SCC4: insert port configuration here */
+ cpmp->cp_sicr &= 0xC0FFFFFF;
+ cpmp->cp_sicr |= 0x1BFFFFFF;
pinfo->brg = 4;
}
-------------- next part --------------
Index: stable/drivers/serial/cpm_uart/cpm_uart_core.c
===================================================================
--- stable.orig/drivers/serial/cpm_uart/cpm_uart_core.c 2005-12-07
15:30:42.000000000 -0200
+++ stable/drivers/serial/cpm_uart/cpm_uart_core.c 2005-12-08
12:39:11.000000000 -0200
@@ -467,6 +467,7 @@
/* free interrupt handler */
free_irq(port->irq, port);
+#if 0
/* If the port is not the console, disable Rx and Tx. */
if (!(pinfo->flags & FLAG_CONSOLE)) {
/* Wait for all the BDs marked sent */
@@ -492,6 +493,7 @@
/* Shut them really down */
cpm_line_cr_cmd(line, CPM_CR_STOP_TX);
}
+#endif
}
static void cpm_uart_set_termios(struct uart_port *port,
@@ -896,7 +898,7 @@
pinfo->sccp->scc_gsmrl &= ~(SCC_GSMRL_ENR | SCC_GSMRL_ENT);
}
- ret = cpm_uart_allocbuf(pinfo, 0);
+ ret = cpm_uart_allocbuf(pinfo, 1);
if (ret)
return ret;
@@ -912,10 +914,12 @@
static void cpm_uart_release_port(struct uart_port *port)
{
+#if 0
struct uart_cpm_port *pinfo = (struct uart_cpm_port *)port;
if (!(pinfo->flags & FLAG_CONSOLE))
cpm_uart_freebuf(pinfo);
+#endif
}
/*
