On Wed, Jun 14, 2017 at 6:08 AM, Christopher Bostic
<cbos...@linux.vnet.ibm.com> wrote:
> Describe new optional property 'external-signal'. When present in the
> system device tree an exernal signal is generated on watchdog timeout.
>
> Describe new optional property 'no-system-reset'. When present in the
> system device tree no system reset is to occur on watchdog timeout.
> System reset in this case is managed by one of the other watchogs
> available.
>
> Signed-off-by: Christopher Bostic <cbos...@linux.vnet.ibm.com>
> ---
> Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt
> b/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt
> index c5e74d7..4099ea5 100644
> --- a/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt
> +++ b/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt
> @@ -8,9 +8,20 @@ Required properties:
> - reg: physical base address of the controller and length of memory mapped
> region
>
> +Optional properties:
> + - external-signal: If the property is present then an external signal is to
> + be generated on watchdog timeout. If absent, external signal is not
> + generated.
> +
> + - no-system-reset: If the property is present then system will not be reset
> + on watchdog timeout. In this case one of the other watchdogs will handle
> + reset. If absent then the watchdog resets the system on timeout.
I'm not sure that this describes the hardware. The datasheet says:
Whenever timeout ocurs, WDT can program to generate 6 types of signals:
* ARM reset signal: to reset ARM CPU only
* SOC reset signal: to reset SOC part function
* System reset signal: to reset full chip
* Interrupt signal: to interrupt CPU
* Eternal signal: to external reset counter (only WDT1 and WDT2)
* Alternate boot signal: to boot from alternate block
I think your bindings should describe these modes where possible.
Cheers,
Joel
> +
> Example:
>
> wdt1: watchdog@1e785000 {
> compatible = "aspeed,ast2400-wdt";
> reg = <0x1e785000 0x1c>;
> + external-signal;
> + no-system-reset;
> };
> --
> 1.8.2.2
>
