linux/arch/sparc64/prom/console.c
David S. Miller c73fcc846c [SPARC]: Fix serial console device detection.
The current scheme works on static interpretation of text names, which
is wrong.

The output-device setting, for example, must be resolved via an alias
or similar to a full path name to the console device.

Paths also contain an optional set of 'options', which starts with a
colon at the end of the path.  The option area is used to specify
which of two serial ports ('a' or 'b') the path refers to when a
device node drives multiple ports.  'a' is assumed if the option
specification is missing.

This was caught by the UltraSPARC-T1 simulator.  The 'output-device'
property was set to 'ttya' and we didn't pick upon the fact that this
is an OBP alias set to '/virtual-devices/console'.  Instead we saw it
as the first serial console device, instead of the hypervisor console.

The infrastructure is now there to take advantage of this to resolve
the console correctly even in multi-head situations in fbcon too.

Thanks to Greg Onufer for the bug report.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-20 16:59:26 -07:00

76 lines
1.6 KiB
C

/* $Id: console.c,v 1.9 1997/10/29 07:41:43 ecd Exp $
* console.c: Routines that deal with sending and receiving IO
* to/from the current console device using the PROM.
*
* Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
* Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <asm/openprom.h>
#include <asm/oplib.h>
#include <asm/system.h>
#include <linux/string.h>
extern int prom_stdin, prom_stdout;
/* Non blocking get character from console input device, returns -1
* if no input was taken. This can be used for polling.
*/
__inline__ int
prom_nbgetchar(void)
{
char inc;
if (p1275_cmd("read", P1275_ARG(1,P1275_ARG_OUT_BUF)|
P1275_INOUT(3,1),
prom_stdin, &inc, P1275_SIZE(1)) == 1)
return inc;
else
return -1;
}
/* Non blocking put character to console device, returns -1 if
* unsuccessful.
*/
__inline__ int
prom_nbputchar(char c)
{
char outc;
outc = c;
if (p1275_cmd("write", P1275_ARG(1,P1275_ARG_IN_BUF)|
P1275_INOUT(3,1),
prom_stdout, &outc, P1275_SIZE(1)) == 1)
return 0;
else
return -1;
}
/* Blocking version of get character routine above. */
char
prom_getchar(void)
{
int character;
while((character = prom_nbgetchar()) == -1) ;
return (char) character;
}
/* Blocking version of put character routine above. */
void
prom_putchar(char c)
{
prom_nbputchar(c);
return;
}
void
prom_puts(const char *s, int len)
{
p1275_cmd("write", P1275_ARG(1,P1275_ARG_IN_BUF)|
P1275_INOUT(3,1),
prom_stdout, s, P1275_SIZE(len));
}