The goal of the document is to illustrate how to enable and use watchdog of SP7021.
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Source files of SP7021 can be downloaded from GitHub or Yocto server of SP7021. Refer to https://github.com/sunplus-plus1/SP7021 or 2. HOW TO GET SOURCE FILE AND PACKAGE.
2. Enable watchdog driver
Run make kconfig command in project top folder, or go to linux/kernel folder and run make menuconfig command. When “Linux/arm 5.4.35 Kernel Configuration” menu pops up, please use arrow key to move cursor down to “Device Drivers”. Refer to screenshot below, cursor is moved to “Device Drivers”:
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Press <Enter> to enter “Device Driver” sub-menu. Next, move cursor down to “Watchdog Timer Support” and press <Space> or “y” to enable it. Refer to screenshot below, “Watchdog Timer Support” is enabled:
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Next, press <Enter> to enter “Watchdog Timer Support” sub-menu. Next, move cursor down to “Sunplus to “Device Drivers > Watchdog Timer Support > Sunplus watchdog support” and press <Space> or “y” to enable it. Refer to screenshot below, “Sunplus watchdog support” is enabled:
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Refer to the following C example code of watchdog setup and feeding application. The application setups, starts, and then feeds watchdog every 10 12 seconds. Note that the The maximum time-out time of watchdog of SP7021 is now about 11 seconds. Any value higher than 11 is invalid.have no limit.
watchdog.c
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#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <fcntl.h> #include <pthread.h> #include <sys/ioctl.h> #define WATCHDOG_IOCTL_BASE 'W' #define WDIOC_SETOPTIONS _IOR(WATCHDOG_IOCTL_BASE, 4, int) #define WDIOC_KEEPALIVE _IOR(WATCHDOG_IOCTL_BASE, 5, int) #define WDIOC_SETTIMEOUT _IOWR(WATCHDOG_IOCTL_BASE, 6, int) #define WDIOS_DISABLECARD 1 #define WDIOS_ENABLECARD 2 #define WDIOC_GETTIMELEFT _IOR(WATCHDOG_IOCTL_BASE, 10, int) int 2 ret; int wd_fd; volatile int wd_feed_time = 8; 12; // Feed watchdog every 812 second by default. int wd_timeout = 10; 15; // Timeout time of watchdog. Reset event occurs if watchdog is not fed within this time. //* Aa thread forfeed feedingdog watchdog.*/ void * feedwdt_thd() { int ret; while (1) { // Feed (reset) watchdog. ret = ioctl(wd_fd, WDIOC_KEEPALIVE, 0); if (ret != 0) { printf("FailedFeed towatchdog feedfailed. watchdog!\n"); close(wd_fd); } else { printf("Feed watchdog every %d seconds.\n", wd_feed_time); } } sleep(wd_feed_time); } } /* a thread read counter and print the value */ void *readwdt_thd() { int arg; int i; while(1) { ret = ioctl(wd_fd, WDIOC_GETTIMELEFT, &arg); if (ret != 0) { printf("get data failed. \n"); } printf("cnt value is 0x%x\n", arg); usleep(200000); } } int main(void) { pthread_t wd_feed_thread; pthread_t wd_read_thread; int wd_option; char str[10]; int num = 0; int ret char* ptr = str; // Get file handle of watchdog device. wd_fd = open("/dev/watchdog0", O_WRONLY); if (wd_fd == -1) { perror("watchdog"); exit(EXIT_FAILURE); } // Enable wacthdog. wd_option = WDIOS_ENABLECARD; ret = ioctl(wd_fd, WDIOC_SETOPTIONS, &wd_option); if (ret != 0) { printf("Failed to start watchdog!\n"); close(wd_fd); return -1; } // Setup timeout time. ret = ioctl(wd_fd, WDIOC_SETTIMEOUT, &wd_timeout); if (ret != 0) { printf("Failed to set timeout time!\n"); close(wd_fd); return -1; } // Create a thread for feeding watchdog. ret = pthread_create(&wd_feed_thread, NULL, feedwdt_thd, NULL); if (ret<ret < 0) printf("Failed to create feeddog thread!\n"); while #if 0 // Create a thread for reading and printing counter value. ret = pthread_create(&wd_read_thread, NULL, readwdt_thd, NULL); if (ret < 0) printf("Failed to create read counter thread!\n"); #endif while(1) { printf("Press 'e' to disable watchdog and exit.\n"); printf("Enter a number for new feed time (defaultcurrent feed time is 8%d seconds, timeout time is 10%d seconds):\n", wd_feed_time, wd_timeout); scanf("%s", str); //printf("debug why feedtime invarible %s\n",str); if (!strcmp(str,"e")) { // Disable watchdog. wd_option = WDIOS_DISABLECARD; ret = ioctl(wd_fd, WDIOC_SETOPTIONS, &wd_option); if (ret != 0) { printf("Failed to stop watchdog!\n"); } } printf("Disabled watchdog!\n"); close(wd_fd); break; } } if (strspn(str, "0123456789") == strlen(str)) { // Get new feed time. num = atoi(str); if (num > 0) { wd_feed_time = num; } else { printf("Feed time can not be zero!\n"); } } } else { printf("Invalid feed time!\n"); } } } } return 0; } |
Reference Makefile (You need to modify CC path):
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CC=/home/your_home_dir/your_sp7021_project_folder/crossgcc/arm-linux-gnueabihf/bin/arm-linux-gnueabihf-gcc LDFLAGS=-lpthread .PHONY: all clean all: watchdog watchdog: watchdog.c $(CC) $< -o $@ $(LDFLAGS) clean: rm -f watchdog |
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