Hello, Thank for Guenter's advice, add a new driver to support SAMA5D4 watchdog timer. Because the watchdog WDT_MR register can be written more than once, its work mechanism is different from the previous one. Open the device file to enable the watchdog hardware, close to disable it, and ping it from the user space directly to keep it alive. Best Regards, Wenyou Yang Wenyou Yang (2): drivers: watchdog: add a driver to support SAMA5D4 watchdog timer Documentation: dt: binding: atmel-sama5d4-wdt: for SAMA5D4 watchdog driver .../bindings/watchdog/atmel-sama5d4-wdt.txt | 35 +++ drivers/watchdog/Kconfig | 9 + drivers/watchdog/Makefile | 1 + drivers/watchdog/at91sam9_wdt.h | 4 + drivers/watchdog/atmel_wdt.c | 290 ++++++++++++++++++++ 5 files changed, 339 insertions(+) create mode 100644 Documentation/devicetree/bindings/watchdog/atmel-sama5d4-wdt.txt create mode 100644 drivers/watchdog/atmel_wdt.c -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html