• Wenyou Yang's avatar
    watchdog: add a driver to support SAMA5D4 watchdog timer · 76534860
    Wenyou Yang authored
    From SAMA5D4, the watchdog timer is upgrated with a new feature,
    which is describled as in the datasheet, "WDT_MR can be written
    until a LOCKMR command is issued in WDT_CR".
    That is to say, as long as the bootstrap and u-boot don't issue
    a LOCKMR command, WDT_MR can be written more than once in the driver.
    So the SAMA5D4 watchdog driver's implementation is different from
    the at91sam9260 watchdog driver implemented in file at91sam9_wdt.c.
    The user application open the device file to enable the watchdog timer
    hardware, and close to disable it, and set the watchdog timer timeout
    by seting WDV and WDD fields of WDT_MR register, and ping the watchdog
    by issuing WDRSTT command to WDT_CR register with hard-coded key.
    Signed-off-by: default avatarWenyou Yang <wenyou.yang@atmel.com>
    Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
    Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
at91sam9_wdt.h 1.49 KB