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/console.c b/common/console.c
index 6f0846f..89aeab6 100644
--- a/common/console.c
+++ b/common/console.c
@@ -93,6 +93,76 @@
return error;
}
+#if defined(CONFIG_CONSOLE_MUX)
+/** Console I/O multiplexing *******************************************/
+
+static device_t *tstcdev;
+device_t **console_devices[MAX_FILES];
+int cd_count[MAX_FILES];
+
+/*
+ * This depends on tstc() always being called before getc().
+ * This is guaranteed to be true because this routine is called
+ * only from fgetc() which assures it.
+ * No attempt is made to demultiplex multiple input sources.
+ */
+static int iomux_getc(void)
+{
+ unsigned char ret;
+
+ /* This is never called with testcdev == NULL */
+ ret = tstcdev->getc();
+ tstcdev = NULL;
+ return ret;
+}
+
+static int iomux_tstc(int file)
+{
+ int i, ret;
+ device_t *dev;
+
+ disable_ctrlc(1);
+ for (i = 0; i < cd_count[file]; i++) {
+ dev = console_devices[file][i];
+ if (dev->tstc != NULL) {
+ ret = dev->tstc();
+ if (ret > 0) {
+ tstcdev = dev;
+ disable_ctrlc(0);
+ return ret;
+ }
+ }
+ }
+ disable_ctrlc(0);
+
+ return 0;
+}
+
+static void iomux_putc(int file, const char c)
+{
+ int i;
+ device_t *dev;
+
+ for (i = 0; i < cd_count[file]; i++) {
+ dev = console_devices[file][i];
+ if (dev->putc != NULL)
+ dev->putc(c);
+ }
+}
+
+static void iomux_puts(int file, const char *s)
+{
+ int i;
+ device_t *dev;
+
+ for (i = 0; i < cd_count[file]; i++) {
+ dev = console_devices[file][i];
+ if (dev->puts != NULL)
+ dev->puts(s);
+ }
+}
+#endif /* defined(CONFIG_CONSOLE_MUX) */
+
/** U-Boot INITIAL CONSOLE-NOT COMPATIBLE FUNCTIONS *************************/
void serial_printf (const char *fmt, ...)
@@ -114,8 +184,31 @@
int fgetc (int file)
{
- if (file < MAX_FILES)
+ if (file < MAX_FILES) {
+#if defined(CONFIG_CONSOLE_MUX)
+ /*
+ * Effectively poll for input wherever it may be available.
+ */
+ for (;;) {
+ /*
+ * Upper layer may have already called tstc() so
+ * check for that first.
+ */
+ if (tstcdev != NULL)
+ return iomux_getc();
+ iomux_tstc(file);
+#ifdef CONFIG_WATCHDOG
+ /*
+ * If the watchdog must be rate-limited then it should
+ * already be handled in board-specific code.
+ */
+ udelay(1);
+#endif
+ }
+#else
return stdio_devices[file]->getc ();
+#endif
+ }
return -1;
}
@@ -123,7 +216,11 @@
int ftstc (int file)
{
if (file < MAX_FILES)
+#if defined(CONFIG_CONSOLE_MUX)
+ return iomux_tstc(file);
+#else
return stdio_devices[file]->tstc ();
+#endif
return -1;
}
@@ -131,13 +228,21 @@
void fputc (int file, const char c)
{
if (file < MAX_FILES)
+#if defined(CONFIG_CONSOLE_MUX)
+ iomux_putc(file, c);
+#else
stdio_devices[file]->putc (c);
+#endif
}
void fputs (int file, const char *s)
{
if (file < MAX_FILES)
+#if defined(CONFIG_CONSOLE_MUX)
+ iomux_puts(file, s);
+#else
stdio_devices[file]->puts (s);
+#endif
}
void fprintf (int file, const char *fmt, ...)
@@ -407,6 +512,9 @@
#ifdef CONFIG_SYS_CONSOLE_ENV_OVERWRITE
int i;
#endif /* CONFIG_SYS_CONSOLE_ENV_OVERWRITE */
+#ifdef CONFIG_CONSOLE_MUX
+ int iomux_err = 0;
+#endif
/* set default handlers at first */
gd->jt[XF_getc] = serial_getc;
@@ -425,6 +533,14 @@
inputdev = search_device (DEV_FLAGS_INPUT, stdinname);
outputdev = search_device (DEV_FLAGS_OUTPUT, stdoutname);
errdev = search_device (DEV_FLAGS_OUTPUT, stderrname);
+#ifdef CONFIG_CONSOLE_MUX
+ iomux_err = iomux_doenv(stdin, stdinname);
+ iomux_err += iomux_doenv(stdout, stdoutname);
+ iomux_err += iomux_doenv(stderr, stderrname);
+ if (!iomux_err)
+ /* Successful, so skip all the code below. */
+ goto done;
+#endif
}
/* if the devices are overwritten or not found, use default device */
if (inputdev == NULL) {
@@ -438,15 +554,34 @@
}
/* Initializes output console first */
if (outputdev != NULL) {
+#ifdef CONFIG_CONSOLE_MUX
+ /* need to set a console if not done above. */
+ iomux_doenv(stdout, outputdev->name);
+#else
console_setfile (stdout, outputdev);
+#endif
}
if (errdev != NULL) {
+#ifdef CONFIG_CONSOLE_MUX
+ /* need to set a console if not done above. */
+ iomux_doenv(stderr, errdev->name);
+#else
console_setfile (stderr, errdev);
+#endif
}
if (inputdev != NULL) {
+#ifdef CONFIG_CONSOLE_MUX
+ /* need to set a console if not done above. */
+ iomux_doenv(stdin, inputdev->name);
+#else
console_setfile (stdin, inputdev);
+#endif
}
+#ifdef CONFIG_CONSOLE_MUX
+done:
+#endif
+
gd->flags |= GD_FLG_DEVINIT; /* device initialization completed */
#ifndef CONFIG_SYS_CONSOLE_INFO_QUIET
@@ -455,21 +590,33 @@
if (stdio_devices[stdin] == NULL) {
puts ("No input devices available!\n");
} else {
+#ifdef CONFIG_CONSOLE_MUX
+ iomux_printdevs(stdin);
+#else
printf ("%s\n", stdio_devices[stdin]->name);
+#endif
}
puts ("Out: ");
if (stdio_devices[stdout] == NULL) {
puts ("No output devices available!\n");
} else {
+#ifdef CONFIG_CONSOLE_MUX
+ iomux_printdevs(stdout);
+#else
printf ("%s\n", stdio_devices[stdout]->name);
+#endif
}
puts ("Err: ");
if (stdio_devices[stderr] == NULL) {
puts ("No error devices available!\n");
} else {
+#ifdef CONFIG_CONSOLE_MUX
+ iomux_printdevs(stderr);
+#else
printf ("%s\n", stdio_devices[stderr]->name);
+#endif
}
#endif /* CONFIG_SYS_CONSOLE_INFO_QUIET */
@@ -524,11 +671,18 @@
if (outputdev != NULL) {
console_setfile (stdout, outputdev);
console_setfile (stderr, outputdev);
+#ifdef CONFIG_CONSOLE_MUX
+ console_devices[stdout][0] = outputdev;
+ console_devices[stderr][0] = outputdev;
+#endif
}
/* Initializes input console */
if (inputdev != NULL) {
console_setfile (stdin, inputdev);
+#ifdef CONFIG_CONSOLE_MUX
+ console_devices[stdin][0] = inputdev;
+#endif
}
gd->flags |= GD_FLG_DEVINIT; /* device initialization completed */