[PATCH 6/5] watchdog: Document reboot API

[rdunlap@infradead.org (Randy Dunlap)]

On 05/10/2014 09:23 AM, Guenter Roeck wrote:
> Document the new reboot API functionality.
> 
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---
>  Documentation/watchdog/watchdog-kernel-api.txt | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt
> index a0438f3..f8f0f18 100644
> --- a/Documentation/watchdog/watchdog-kernel-api.txt
> +++ b/Documentation/watchdog/watchdog-kernel-api.txt
> @@ -90,6 +90,8 @@ struct watchdog_ops {
>  	int (*stop)(struct watchdog_device *);
>  	/* optional operations */
>  	int (*ping)(struct watchdog_device *);
> +	void (*reboot)(struct watchdog_device *, enum reboot_mode,
> +		       const char *);
>  	unsigned int (*status)(struct watchdog_device *);
>  	int (*set_timeout)(struct watchdog_device *, unsigned int);
>  	unsigned int (*get_timeleft)(struct watchdog_device *);
> @@ -148,6 +150,10 @@ they are supported. These optional routines/operations are:
>    info structure).
>  * status: this routine checks the status of the watchdog timer device. The
>    status of the device is reported with watchdog WDIOF_* status flags/bits.
> +* reboot: if this routine is present, it may be called to reboot the system.
> +  Parameters are the pointer to the watchdog device, the reboot mode, and a
> +  command string. The latter two parameters are the system reboot mode
> +  and the cmd parameter passed to machine_restart().
>  * set_timeout: this routine checks and changes the timeout of the watchdog
>    timer device. It returns 0 on success, -EINVAL for "parameter out of range"
>    and -EIO for "could not write value to the watchdog". On success this
> @@ -224,3 +230,11 @@ the device tree (if the module timeout parameter is invalid). Best practice is
>  to set the default timeout value as timeout value in the watchdog_device and
>  then use this function to set the user "preferred" timeout value.
>  This routine returns zero on success and a negative errno code for failure.
> +
> +The watchdog_do_reboot function can be used reboot the system. This is intended

                                               to reboot

> +to be used in systems which do not have an explicit reboot capability, but
> +implement reboot by programming the watchdog to expire immediately. If the
> +function is called, and a watchdog driver with reboot functionality was
> +previously registered, the reboot function of that driver will be called.
> +Architecture code should call watchdog_do_reboot from its machine_reboot
> +function after other means to reboot the system failed.
> 

Thanks for the Doc patch.

-- 
~Randy