2 * Generic watchdog defines. Derived from..
4 * Berkshire PC Watchdog Defines
5 * by Ken Hollis <khollis@bitgate.com>
8 #ifndef _LINUX_WATCHDOG_H
9 #define _LINUX_WATCHDOG_H
12 #include <linux/bitops.h>
13 #include <linux/device.h>
14 #include <linux/cdev.h>
15 #include <linux/notifier.h>
16 #include <uapi/linux/watchdog.h>
19 struct watchdog_device
;
20 struct watchdog_core_data
;
22 /** struct watchdog_ops - The watchdog-devices operations
24 * @owner: The module owner.
25 * @start: The routine for starting the watchdog device.
26 * @stop: The routine for stopping the watchdog device.
27 * @ping: The routine that sends a keepalive ping to the watchdog device.
28 * @status: The routine that shows the status of the watchdog device.
29 * @set_timeout:The routine for setting the watchdog devices timeout value (in seconds).
30 * @get_timeleft:The routine that gets the time left before a reset (in seconds).
31 * @restart: The routine for restarting the machine.
32 * @ioctl: The routines that handles extra ioctl calls.
34 * The watchdog_ops structure contains a list of low-level operations
35 * that control a watchdog device. It also contains the module that owns
36 * these operations. The start and stop function are mandatory, all other
37 * functions are optional.
41 /* mandatory operations */
42 int (*start
)(struct watchdog_device
*);
43 int (*stop
)(struct watchdog_device
*);
44 /* optional operations */
45 int (*ping
)(struct watchdog_device
*);
46 unsigned int (*status
)(struct watchdog_device
*);
47 int (*set_timeout
)(struct watchdog_device
*, unsigned int);
48 unsigned int (*get_timeleft
)(struct watchdog_device
*);
49 int (*restart
)(struct watchdog_device
*);
50 long (*ioctl
)(struct watchdog_device
*, unsigned int, unsigned long);
53 /** struct watchdog_device - The structure that defines a watchdog device
55 * @id: The watchdog's ID. (Allocated by watchdog_register_device)
56 * @parent: The parent bus device
57 * @groups: List of sysfs attribute groups to create when creating the
59 * @info: Pointer to a watchdog_info structure.
60 * @ops: Pointer to the list of watchdog operations.
61 * @bootstatus: Status of the watchdog device at boot.
62 * @timeout: The watchdog devices timeout value (in seconds).
63 * @min_timeout:The watchdog devices minimum timeout value (in seconds).
64 * @max_timeout:The watchdog devices maximum timeout value (in seconds).
65 * @reboot_nb: The notifier block to stop watchdog on reboot.
66 * @restart_nb: The notifier block to register a restart function.
67 * @driver_data:Pointer to the drivers private data.
68 * @wd_data: Pointer to watchdog core internal data.
69 * @status: Field that contains the devices internal status bits.
70 * @deferred: entry in wtd_deferred_reg_list which is used to
71 * register early initialized watchdogs.
73 * The watchdog_device structure contains all information about a
74 * watchdog timer device.
76 * The driver-data field may not be accessed directly. It must be accessed
77 * via the watchdog_set_drvdata and watchdog_get_drvdata helpers.
79 * The lock field is for watchdog core internal use only and should not be
82 struct watchdog_device
{
84 struct device
*parent
;
85 const struct attribute_group
**groups
;
86 const struct watchdog_info
*info
;
87 const struct watchdog_ops
*ops
;
88 unsigned int bootstatus
;
90 unsigned int min_timeout
;
91 unsigned int max_timeout
;
92 struct notifier_block reboot_nb
;
93 struct notifier_block restart_nb
;
95 struct watchdog_core_data
*wd_data
;
97 /* Bit numbers for status flags */
98 #define WDOG_ACTIVE 0 /* Is the watchdog running/active */
99 #define WDOG_NO_WAY_OUT 1 /* Is 'nowayout' feature set ? */
100 #define WDOG_STOP_ON_REBOOT 2 /* Should be stopped on reboot */
101 struct list_head deferred
;
104 #define WATCHDOG_NOWAYOUT IS_BUILTIN(CONFIG_WATCHDOG_NOWAYOUT)
105 #define WATCHDOG_NOWAYOUT_INIT_STATUS (WATCHDOG_NOWAYOUT << WDOG_NO_WAY_OUT)
107 /* Use the following function to check whether or not the watchdog is active */
108 static inline bool watchdog_active(struct watchdog_device
*wdd
)
110 return test_bit(WDOG_ACTIVE
, &wdd
->status
);
113 /* Use the following function to set the nowayout feature */
114 static inline void watchdog_set_nowayout(struct watchdog_device
*wdd
, bool nowayout
)
117 set_bit(WDOG_NO_WAY_OUT
, &wdd
->status
);
120 /* Use the following function to stop the watchdog on reboot */
121 static inline void watchdog_stop_on_reboot(struct watchdog_device
*wdd
)
123 set_bit(WDOG_STOP_ON_REBOOT
, &wdd
->status
);
126 /* Use the following function to check if a timeout value is invalid */
127 static inline bool watchdog_timeout_invalid(struct watchdog_device
*wdd
, unsigned int t
)
130 * The timeout is invalid if
131 * - the requested value is smaller than the configured minimum timeout,
133 * - a maximum timeout is configured, and the requested value is larger
134 * than the maximum timeout.
136 return t
< wdd
->min_timeout
||
137 (wdd
->max_timeout
&& t
> wdd
->max_timeout
);
140 /* Use the following functions to manipulate watchdog driver specific data */
141 static inline void watchdog_set_drvdata(struct watchdog_device
*wdd
, void *data
)
143 wdd
->driver_data
= data
;
146 static inline void *watchdog_get_drvdata(struct watchdog_device
*wdd
)
148 return wdd
->driver_data
;
151 /* drivers/watchdog/watchdog_core.c */
152 void watchdog_set_restart_priority(struct watchdog_device
*wdd
, int priority
);
153 extern int watchdog_init_timeout(struct watchdog_device
*wdd
,
154 unsigned int timeout_parm
, struct device
*dev
);
155 extern int watchdog_register_device(struct watchdog_device
*);
156 extern void watchdog_unregister_device(struct watchdog_device
*);
158 #endif /* ifndef _LINUX_WATCHDOG_H */