Re: [PATCH 5/6] watchdog: pretimeout: add device specific notifier pretimeout governor

[Guenter Roeck <linux@roeck-us.net>]

On 11/20/2015 11:11 PM, Vladimir Zapolskiy wrote:
> Device watchdog pretimeout governor sends a notification back to a
> watchdog device for further handling. This governor does nothing, if
> watchdog driver does not define a pretimeout callback.
>

I can not make up my mind - should this be "device" or "driver" specific ?

Guenter

> Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
> ---
>   drivers/watchdog/Kconfig             | 15 +++++++++++
>   drivers/watchdog/Makefile            |  1 +
>   drivers/watchdog/pretimeout_device.c | 49 ++++++++++++++++++++++++++++++++++++
>   include/linux/watchdog.h             |  2 ++
>   4 files changed, 67 insertions(+)
>   create mode 100644 drivers/watchdog/pretimeout_device.c
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 7e9e2bb..6c1f7e1 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -1662,6 +1662,13 @@ config WATCHDOG_PRETIMEOUT_DEFAULT_GOV_USERSPACE
>   	  Use userspace notifier watchdog pretimeout governor
>   	  by default.
>
> +config WATCHDOG_PRETIMEOUT_DEFAULT_GOV_DEVICE
> +	bool "device"
> +	select WATCHDOG_PRETIMEOUT_GOV_DEVICE
> +	help
> +	  Use device specific watchdog pretimeout event handler
> +	  by default.
> +
>   endchoice
>
>   config WATCHDOG_PRETIMEOUT_GOV_NOOP
> @@ -1683,6 +1690,14 @@ config WATCHDOG_PRETIMEOUT_GOV_USERSPACE
>   	  pretimeout event send a notification to userspace for
>   	  further handling.
>
> +config WATCHDOG_PRETIMEOUT_GOV_DEVICE
> +	tristate "Own device watchdog pretimeout governor"
> +	help
> +	  Device watchdog pretimeout governor sends a notification
> +	  back to a watchdog device for further handling. This governor
> +	  does nothing, if watchdog driver does not define a pretimeout
> +	  callback.
> +
>   endif # WATCHDOG_PRETIMEOUT_GOV
>
>   endif # WATCHDOG
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index 7d6755b..0717b64 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -11,6 +11,7 @@ watchdog-$(CONFIG_WATCHDOG_PRETIMEOUT_GOV)	+= watchdog_pretimeout.o
>   obj-$(CONFIG_WATCHDOG_PRETIMEOUT_GOV_NOOP)	+= pretimeout_noop.o
>   obj-$(CONFIG_WATCHDOG_PRETIMEOUT_GOV_PANIC)	+= pretimeout_panic.o
>   obj-$(CONFIG_WATCHDOG_PRETIMEOUT_GOV_USERSPACE)	+= pretimeout_userspace.o
> +obj-$(CONFIG_WATCHDOG_PRETIMEOUT_GOV_DEVICE)	+= pretimeout_device.o
>
>   # Only one watchdog can succeed. We probe the ISA/PCI/USB based
>   # watchdog-cards first, then the architecture specific watchdog
> diff --git a/drivers/watchdog/pretimeout_device.c b/drivers/watchdog/pretimeout_device.c
> new file mode 100644
> index 0000000..4ce992b
> --- /dev/null
> +++ b/drivers/watchdog/pretimeout_device.c
> @@ -0,0 +1,49 @@
> +/*
> + * Copyright (C) 2015 Mentor Graphics
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + */
> +
> +#include <linux/module.h>
> +#include <linux/watchdog.h>
> +
> +#include <watchdog_pretimeout.h>
> +
> +/**
> + * pretimeout_device - Run device specific handler on watchdog pretimeout event
> + * @wdd - watchdog_device
> + *
> + */
> +static void pretimeout_device(struct watchdog_device *wdd)
> +{
> +	if (wdd->ops->pretimeout)
> +		wdd->ops->pretimeout(wdd);
> +}
> +
> +static struct watchdog_governor watchdog_gov_device = {
> +	.name		= "device",
> +	.pretimeout	= pretimeout_device,
> +#ifdef CONFIG_WATCHDOG_PRETIMEOUT_DEFAULT_GOV_DEVICE
> +	.is_default	= true,
> +#endif
> +};
> +
> +static int __init watchdog_gov_device_register(void)
> +{
> +	return watchdog_register_governor(&watchdog_gov_device);
> +}
> +
> +static void __exit watchdog_gov_device_unregister(void)
> +{
> +	watchdog_unregister_governor(&watchdog_gov_device);
> +}
> +module_init(watchdog_gov_device_register);
> +module_exit(watchdog_gov_device_unregister);
> +
> +MODULE_AUTHOR("Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>");
> +MODULE_DESCRIPTION("Device specific watchdog pretimeout governor");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
> index 960223e..597dcfb 100644
> --- a/include/linux/watchdog.h
> +++ b/include/linux/watchdog.h
> @@ -27,6 +27,7 @@ struct watchdog_governor;
>    * @status:	The routine that shows the status of the watchdog device.
>    * @set_timeout:The routine for setting the watchdog devices timeout value (in seconds).
>    * @get_timeleft:The routine that gets the time left before a reset (in seconds).
> + * @pretimeout: The routine that runs driver specific handler of pretimeout event.
>    * @ref:	The ref operation for dyn. allocated watchdog_device structs
>    * @unref:	The unref operation for dyn. allocated watchdog_device structs
>    * @ioctl:	The routines that handles extra ioctl calls.
> @@ -46,6 +47,7 @@ struct watchdog_ops {
>   	unsigned int (*status)(struct watchdog_device *);
>   	int (*set_timeout)(struct watchdog_device *, unsigned int);
>   	unsigned int (*get_timeleft)(struct watchdog_device *);
> +	void (*pretimeout)(struct watchdog_device *);
>   	void (*ref)(struct watchdog_device *);
>   	void (*unref)(struct watchdog_device *);
>   	long (*ioctl)(struct watchdog_device *, unsigned int, unsigned long);
>