diff options
Diffstat (limited to 'Documentation/watchdog')
| -rw-r--r-- | Documentation/watchdog/Makefile | 1 | ||||
| -rw-r--r-- | Documentation/watchdog/src/.gitignore | 2 | ||||
| -rw-r--r-- | Documentation/watchdog/src/Makefile | 5 | ||||
| -rw-r--r-- | Documentation/watchdog/src/watchdog-simple.c | 24 | ||||
| -rw-r--r-- | Documentation/watchdog/src/watchdog-test.c | 105 | ||||
| -rw-r--r-- | Documentation/watchdog/watchdog-api.txt | 2 | ||||
| -rw-r--r-- | Documentation/watchdog/watchdog-kernel-api.txt | 33 | ||||
| -rw-r--r-- | Documentation/watchdog/wdt.txt | 2 |
8 files changed, 35 insertions, 139 deletions
diff --git a/Documentation/watchdog/Makefile b/Documentation/watchdog/Makefile deleted file mode 100644 index 6018f45f2471..000000000000 --- a/Documentation/watchdog/Makefile +++ /dev/null @@ -1 +0,0 @@ -subdir-y := src diff --git a/Documentation/watchdog/src/.gitignore b/Documentation/watchdog/src/.gitignore deleted file mode 100644 index ac90997dba93..000000000000 --- a/Documentation/watchdog/src/.gitignore +++ /dev/null @@ -1,2 +0,0 @@ -watchdog-simple -watchdog-test diff --git a/Documentation/watchdog/src/Makefile b/Documentation/watchdog/src/Makefile deleted file mode 100644 index 4a892c304983..000000000000 --- a/Documentation/watchdog/src/Makefile +++ /dev/null @@ -1,5 +0,0 @@ -# List of programs to build -hostprogs-y := watchdog-simple watchdog-test - -# Tell kbuild to always build the programs -always := $(hostprogs-y) diff --git a/Documentation/watchdog/src/watchdog-simple.c b/Documentation/watchdog/src/watchdog-simple.c deleted file mode 100644 index ba45803a2216..000000000000 --- a/Documentation/watchdog/src/watchdog-simple.c +++ /dev/null @@ -1,24 +0,0 @@ -#include <stdio.h> -#include <stdlib.h> -#include <unistd.h> -#include <fcntl.h> - -int main(void) -{ - int fd = open("/dev/watchdog", O_WRONLY); - int ret = 0; - if (fd == -1) { - perror("watchdog"); - exit(EXIT_FAILURE); - } - while (1) { - ret = write(fd, "\0", 1); - if (ret != 1) { - ret = -1; - break; - } - sleep(10); - } - close(fd); - return ret; -} diff --git a/Documentation/watchdog/src/watchdog-test.c b/Documentation/watchdog/src/watchdog-test.c deleted file mode 100644 index 6983d05097e2..000000000000 --- a/Documentation/watchdog/src/watchdog-test.c +++ /dev/null @@ -1,105 +0,0 @@ -/* - * Watchdog Driver Test Program - */ - -#include <errno.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <unistd.h> -#include <fcntl.h> -#include <signal.h> -#include <sys/ioctl.h> -#include <linux/types.h> -#include <linux/watchdog.h> - -int fd; -const char v = 'V'; - -/* - * This function simply sends an IOCTL to the driver, which in turn ticks - * the PC Watchdog card to reset its internal timer so it doesn't trigger - * a computer reset. - */ -static void keep_alive(void) -{ - int dummy; - - printf("."); - ioctl(fd, WDIOC_KEEPALIVE, &dummy); -} - -/* - * The main program. Run the program with "-d" to disable the card, - * or "-e" to enable the card. - */ - -static void term(int sig) -{ - int ret = write(fd, &v, 1); - - close(fd); - if (ret < 0) - printf("\nStopping watchdog ticks failed (%d)...\n", errno); - else - printf("\nStopping watchdog ticks...\n"); - exit(0); -} - -int main(int argc, char *argv[]) -{ - int flags; - unsigned int ping_rate = 1; - int ret; - - setbuf(stdout, NULL); - - fd = open("/dev/watchdog", O_WRONLY); - - if (fd == -1) { - printf("Watchdog device not enabled.\n"); - exit(-1); - } - - if (argc > 1) { - if (!strncasecmp(argv[1], "-d", 2)) { - flags = WDIOS_DISABLECARD; - ioctl(fd, WDIOC_SETOPTIONS, &flags); - printf("Watchdog card disabled.\n"); - goto end; - } else if (!strncasecmp(argv[1], "-e", 2)) { - flags = WDIOS_ENABLECARD; - ioctl(fd, WDIOC_SETOPTIONS, &flags); - printf("Watchdog card enabled.\n"); - goto end; - } else if (!strncasecmp(argv[1], "-t", 2) && argv[2]) { - flags = atoi(argv[2]); - ioctl(fd, WDIOC_SETTIMEOUT, &flags); - printf("Watchdog timeout set to %u seconds.\n", flags); - goto end; - } else if (!strncasecmp(argv[1], "-p", 2) && argv[2]) { - ping_rate = strtoul(argv[2], NULL, 0); - printf("Watchdog ping rate set to %u seconds.\n", ping_rate); - } else { - printf("-d to disable, -e to enable, -t <n> to set " \ - "the timeout,\n-p <n> to set the ping rate, and \n"); - printf("run by itself to tick the card.\n"); - goto end; - } - } - - printf("Watchdog Ticking Away!\n"); - - signal(SIGINT, term); - - while(1) { - keep_alive(); - sleep(ping_rate); - } -end: - ret = write(fd, &v, 1); - if (ret < 0) - printf("Stopping watchdog ticks failed (%d)...\n", errno); - close(fd); - return 0; -} diff --git a/Documentation/watchdog/watchdog-api.txt b/Documentation/watchdog/watchdog-api.txt index b3a701f48118..0e62ba33b7fb 100644 --- a/Documentation/watchdog/watchdog-api.txt +++ b/Documentation/watchdog/watchdog-api.txt @@ -37,7 +37,7 @@ activates as soon as /dev/watchdog is opened and will reboot unless the watchdog is pinged within a certain time, this time is called the timeout or margin. The simplest way to ping the watchdog is to write some data to the device. So a very simple watchdog daemon would look -like this source file: see Documentation/watchdog/src/watchdog-simple.c +like this source file: see samples/watchdog/watchdog-simple.c A more advanced driver could for example check that a HTTP server is still responding before doing the write call to ping the watchdog. diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt index 7f31125c123e..ea277478982f 100644 --- a/Documentation/watchdog/watchdog-kernel-api.txt +++ b/Documentation/watchdog/watchdog-kernel-api.txt @@ -48,8 +48,10 @@ struct watchdog_device { const struct attribute_group **groups; const struct watchdog_info *info; const struct watchdog_ops *ops; + const struct watchdog_governor *gov; unsigned int bootstatus; unsigned int timeout; + unsigned int pretimeout; unsigned int min_timeout; unsigned int max_timeout; unsigned int min_hw_heartbeat_ms; @@ -74,9 +76,11 @@ It contains following fields: * info: a pointer to a watchdog_info structure. This structure gives some additional information about the watchdog timer itself. (Like it's unique name) * ops: a pointer to the list of watchdog operations that the watchdog supports. +* gov: a pointer to the assigned watchdog device pretimeout governor or NULL. * timeout: the watchdog timer's timeout value (in seconds). This is the time after which the system will reboot if user space does not send a heartbeat request if WDOG_ACTIVE is set. +* pretimeout: the watchdog timer's pretimeout value (in seconds). * min_timeout: the watchdog timer's minimum timeout value (in seconds). If set, the minimum configurable value for 'timeout'. * max_timeout: the watchdog timer's maximum timeout value (in seconds), @@ -121,6 +125,7 @@ struct watchdog_ops { int (*ping)(struct watchdog_device *); unsigned int (*status)(struct watchdog_device *); int (*set_timeout)(struct watchdog_device *, unsigned int); + int (*set_pretimeout)(struct watchdog_device *, unsigned int); unsigned int (*get_timeleft)(struct watchdog_device *); int (*restart)(struct watchdog_device *); void (*ref)(struct watchdog_device *) __deprecated; @@ -188,6 +193,23 @@ they are supported. These optional routines/operations are: If set_timeout is not provided but, WDIOF_SETTIMEOUT is set, the watchdog infrastructure updates the timeout value of the watchdog_device internally to the requested value. + If the pretimeout feature is used (WDIOF_PRETIMEOUT), then set_timeout must + also take care of checking if pretimeout is still valid and set up the timer + accordingly. This can't be done in the core without races, so it is the + duty of the driver. +* set_pretimeout: this routine checks and changes the pretimeout value of + the watchdog. It is optional because not all watchdogs support pretimeout + notification. The timeout value is not an absolute time, but the number of + seconds before the actual timeout would happen. It returns 0 on success, + -EINVAL for "parameter out of range" and -EIO for "could not write value to + the watchdog". A value of 0 disables pretimeout notification. + (Note: the WDIOF_PRETIMEOUT needs to be set in the options field of the + watchdog's info structure). + If the watchdog driver does not have to perform any action but setting the + watchdog_device.pretimeout, this callback can be omitted. That means if + set_pretimeout is not provided but WDIOF_PRETIMEOUT is set, the watchdog + infrastructure updates the pretimeout value of the watchdog_device internally + to the requested value. * get_timeleft: this routines returns the time that's left before a reset. * restart: this routine restarts the machine. It returns 0 on success or a negative errno code for failure. @@ -268,3 +290,14 @@ User should follow the following guidelines for setting the priority: * 128: default restart handler, use if no other handler is expected to be available, and/or if restart is sufficient to restart the entire system * 255: highest priority, will preempt all other restart handlers + +To raise a pretimeout notification, the following function should be used: + +void watchdog_notify_pretimeout(struct watchdog_device *wdd) + +The function can be called in the interrupt context. If watchdog pretimeout +governor framework (kbuild CONFIG_WATCHDOG_PRETIMEOUT_GOV symbol) is enabled, +an action is taken by a preconfigured pretimeout governor preassigned to +the watchdog device. If watchdog pretimeout governor framework is not +enabled, watchdog_notify_pretimeout() prints a notification message to +the kernel log buffer. diff --git a/Documentation/watchdog/wdt.txt b/Documentation/watchdog/wdt.txt index 061c2e35384f..ed2f0b860869 100644 --- a/Documentation/watchdog/wdt.txt +++ b/Documentation/watchdog/wdt.txt @@ -47,4 +47,4 @@ The external event interfaces on the WDT boards are not currently supported. Minor numbers are however allocated for it. -Example Watchdog Driver: see Documentation/watchdog/src/watchdog-simple.c +Example Watchdog Driver: see samples/watchdog/watchdog-simple.c |
