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>
diff --git a/common/iomux.c b/common/iomux.c
new file mode 100644
index 0000000..bdcc853
--- /dev/null
+++ b/common/iomux.c
@@ -0,0 +1,175 @@
+/*
+ * (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 */