Hi Herve,

> On timeout, the watchdog also asserts its dedicated reset line. This
> reset line is connected to the reset controller (part of sysctrl) and,
> if this line is enabled as a possible reset source at the reset
> controller level, it initiates a system reset.

Okay, this seems similar to R-Car SoCs, so multiple things to add from
my side:

* I agree with Krzysztof that the renesas-vendor-binding is not the way
  to go. The information could be either deduced from the register range
  or you could have a link to the syscon describing somehow which reset
  to allow.

But:

* On R-Car, we require the firmware to correctly setup which resets are
  allowed. Only in cases of broken firmware, we override it in the
  system controller driver. The latter could probably be argued here.
  The firmware is old and will probably be not updated anymore.

* If the watchdog driver kind of unconditionally allows its own reset,
  we could keep it very simple and just unconditionally allow watchdog
  resets when probing the sysctrl driver?

* If you don't like this, you could also parse the DT for enabled
  watchdogs when probing the sysctrl driver and act upon findings?

Happy hacking,

   Wolfram