The boot status in the watchdog device struct is updated during
controller probe stage. Application layer can get the boot status
through the command, cat /sys/class/watchdog/watchdogX/bootstatus.
The bootstatus can be,
WDIOF_CARDRESET => the system is reset by WDT SoC reset.
Others => other reset events, e.g., power on reset.
On ASPEED platform, the boot status is recorded in the SCU registers.
- AST2400: Only a bit represents for any WDT reset.
- AST2500/AST2600: The reset triggered by different WDT controllers
can be distinguished by different SCU bits.
Besides, on AST2400 and AST2500, since alternating boot event is
triggered by WDT SoC reset, it is classified as WDIOF_CARDRESET.
Signed-off-by: Chin-Ting Kuo <chin-ting_kuo@xxxxxxxxxxxxxx>