u-boot/common/iomux.c
Gary Jennejohn 16a28ef219 IOMUX: Add console multiplexing support.
Modifications to support console multiplexing.  This is controlled using
CONFIG_SYS_CONSOLE_MUX in the board configuration file.

This allows a user to specify multiple console devices in the environment
with a command like this: setenv stdin serial,nc.  As a result, the user can
enter text on both the serial and netconsole interfaces.

All devices - stdin, stdout and stderr - can be set in this manner.

1) common/iomux.c and include/iomux.h contain the environment setting
implementation.
2) doc/README.iomux contains a somewhat more detailed description.
3) The implementation in (1) is called from common/cmd_nvedit.c to
handle setenv and from common/console.c to handle initialization of
input/output devices at boot time.
4) common/console.c also contains the code needed to poll multiple console
devices for input and send output to all devices registered for output.
5) include/common.h includes iomux.h and common/Makefile generates iomux.o
when CONFIG_SYS_CONSOLE_MUX is set.

Signed-off-by: Gary Jennejohn <garyj@denx.de>
2008-12-07 01:23:35 +01:00

176 lines
4.1 KiB
C

/*
* (C) Copyright 2008
* Gary Jennejohn, DENX Software Engineering GmbH, garyj@denx.de.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <serial.h>
#include <malloc.h>
#ifdef CONFIG_CONSOLE_MUX
void iomux_printdevs(const int console)
{
int i;
device_t *dev;
for (i = 0; i < cd_count[console]; i++) {
dev = console_devices[console][i];
printf("%s ", dev->name);
}
printf("\n");
}
/* This tries to preserve the old list if an error occurs. */
int iomux_doenv(const int console, const char *arg)
{
char *console_args, *temp, **start;
int i, j, k, io_flag, cs_idx, repeat;
device_t *dev;
device_t **cons_set;
console_args = strdup(arg);
if (console_args == NULL)
return 1;
/*
* Check whether a comma separated list of devices was
* entered and count how many devices were entered.
* The array start[] has pointers to the beginning of
* each device name (up to MAX_CONSARGS devices).
*
* Have to do this twice - once to count the number of
* commas and then again to populate start.
*/
i = 0;
temp = console_args;
for (;;) {
temp = strchr(temp, ',');
if (temp != NULL) {
i++;
temp++;
continue;
}
/* There's always one entry more than the number of commas. */
i++;
break;
}
start = (char **)malloc(i * sizeof(char *));
if (start == NULL) {
free(console_args);
return 1;
}
i = 0;
start[0] = console_args;
for (;;) {
temp = strchr(start[i++], ',');
if (temp == NULL)
break;
*temp = '\0';
start[i] = temp + 1;
}
cons_set = (device_t **)calloc(i, sizeof(device_t *));
if (cons_set == NULL) {
free(start);
free(console_args);
return 1;
}
switch (console) {
case stdin:
io_flag = DEV_FLAGS_INPUT;
break;
case stdout:
case stderr:
io_flag = DEV_FLAGS_OUTPUT;
break;
default:
free(start);
free(console_args);
free(cons_set);
return 1;
}
cs_idx = 0;
for (j = 0; j < i; j++) {
/*
* Check whether the device exists and is valid.
* console_assign() also calls search_device(),
* but I need the pointer to the device.
*/
dev = search_device(io_flag, start[j]);
if (dev == NULL)
continue;
/*
* Prevent multiple entries for a device.
*/
repeat = 0;
for (k = 0; k < cs_idx; k++) {
if (dev == cons_set[k]) {
repeat++;
break;
}
}
if (repeat)
continue;
/*
* Try assigning the specified device.
* This could screw up the console settings for apps.
*/
if (console_assign(console, start[j]) < 0)
continue;
#ifdef CONFIG_SERIAL_MULTI
/*
* This was taken from common/cmd_nvedit.c.
* This will never work because serial_assign() returns
* 1 upon error, not -1.
* This would almost always return an error anyway because
* serial_assign() expects the name of a serial device, like
* serial_smc, but the user generally only wants to set serial.
*/
if (serial_assign(start[j]) < 0)
continue;
#endif
cons_set[cs_idx++] = dev;
}
free(console_args);
free(start);
/* failed to set any console */
if (cs_idx == 0) {
free(cons_set);
return 1;
} else {
/* Works even if console_devices[console] is NULL. */
console_devices[console] =
(device_t **)realloc(console_devices[console],
cs_idx * sizeof(device_t *));
if (console_devices[console] == NULL) {
free(cons_set);
return 1;
}
memcpy(console_devices[console], cons_set, cs_idx *
sizeof(device_t *));
cd_count[console] = cs_idx;
}
free(cons_set);
return 0;
}
#endif /* CONFIG_CONSOLE_MUX */