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/cdev.h>
14 #include <linux/device.h>
15 #include <linux/kernel.h>
16 #include <linux/notifier.h>
17 #include <uapi/linux/watchdog.h>
20 struct watchdog_device
;
21 struct watchdog_core_data
;
23 /** struct watchdog_ops - The watchdog-devices operations
25 * @owner: The module owner.
26 * @start: The routine for starting the watchdog device.
27 * @stop: The routine for stopping the watchdog device.
28 * @ping: The routine that sends a keepalive ping to the watchdog device.
29 * @status: The routine that shows the status of the watchdog device.
30 * @set_timeout:The routine for setting the watchdog devices timeout value (in seconds).
31 * @get_timeleft:The routine that gets the time left before a reset (in seconds).
32 * @restart: The routine for restarting the machine.
33 * @ioctl: The routines that handles extra ioctl calls.
35 * The watchdog_ops structure contains a list of low-level operations
36 * that control a watchdog device. It also contains the module that owns
37 * these operations. The start and stop function are mandatory, all other
38 * functions are optional.
42 /* mandatory operations */
43 int (*start
)(struct watchdog_device
*);
44 int (*stop
)(struct watchdog_device
*);
45 /* optional operations */
46 int (*ping
)(struct watchdog_device
*);
47 unsigned int (*status
)(struct watchdog_device
*);
48 int (*set_timeout
)(struct watchdog_device
*, unsigned int);
49 unsigned int (*get_timeleft
)(struct watchdog_device
*);
50 int (*restart
)(struct watchdog_device
*, unsigned long, void *);
51 long (*ioctl
)(struct watchdog_device
*, unsigned int, unsigned long);
54 /** struct watchdog_device - The structure that defines a watchdog device
56 * @id: The watchdog's ID. (Allocated by watchdog_register_device)
57 * @parent: The parent bus device
58 * @groups: List of sysfs attribute groups to create when creating the
60 * @info: Pointer to a watchdog_info structure.
61 * @ops: Pointer to the list of watchdog operations.
62 * @bootstatus: Status of the watchdog device at boot.
63 * @timeout: The watchdog devices timeout value (in seconds).
64 * @min_timeout:The watchdog devices minimum timeout value (in seconds).
65 * @max_timeout:The watchdog devices maximum timeout value (in seconds)
66 * as configurable from user space. Only relevant if
67 * max_hw_heartbeat_ms is not provided.
68 * @min_hw_heartbeat_ms:
69 * Hardware limit for minimum time between heartbeats,
71 * @max_hw_heartbeat_ms:
72 * Hardware limit for maximum timeout, in milli-seconds.
73 * Replaces max_timeout if specified.
74 * @reboot_nb: The notifier block to stop watchdog on reboot.
75 * @restart_nb: The notifier block to register a restart function.
76 * @driver_data:Pointer to the drivers private data.
77 * @wd_data: Pointer to watchdog core internal data.
78 * @status: Field that contains the devices internal status bits.
79 * @deferred: Entry in wtd_deferred_reg_list which is used to
80 * register early initialized watchdogs.
82 * The watchdog_device structure contains all information about a
83 * watchdog timer device.
85 * The driver-data field may not be accessed directly. It must be accessed
86 * via the watchdog_set_drvdata and watchdog_get_drvdata helpers.
88 * The lock field is for watchdog core internal use only and should not be
91 struct watchdog_device
{
93 struct device
*parent
;
94 const struct attribute_group
**groups
;
95 const struct watchdog_info
*info
;
96 const struct watchdog_ops
*ops
;
97 unsigned int bootstatus
;
99 unsigned int min_timeout
;
100 unsigned int max_timeout
;
101 unsigned int min_hw_heartbeat_ms
;
102 unsigned int max_hw_heartbeat_ms
;
103 struct notifier_block reboot_nb
;
104 struct notifier_block restart_nb
;
106 struct watchdog_core_data
*wd_data
;
107 unsigned long status
;
108 /* Bit numbers for status flags */
109 #define WDOG_ACTIVE 0 /* Is the watchdog running/active */
110 #define WDOG_NO_WAY_OUT 1 /* Is 'nowayout' feature set ? */
111 #define WDOG_STOP_ON_REBOOT 2 /* Should be stopped on reboot */
112 #define WDOG_HW_RUNNING 3 /* True if HW watchdog running */
113 struct list_head deferred
;
116 #define WATCHDOG_NOWAYOUT IS_BUILTIN(CONFIG_WATCHDOG_NOWAYOUT)
117 #define WATCHDOG_NOWAYOUT_INIT_STATUS (WATCHDOG_NOWAYOUT << WDOG_NO_WAY_OUT)
119 /* Use the following function to check whether or not the watchdog is active */
120 static inline bool watchdog_active(struct watchdog_device
*wdd
)
122 return test_bit(WDOG_ACTIVE
, &wdd
->status
);
126 * Use the following function to check whether or not the hardware watchdog
129 static inline bool watchdog_hw_running(struct watchdog_device
*wdd
)
131 return test_bit(WDOG_HW_RUNNING
, &wdd
->status
);
134 /* Use the following function to set the nowayout feature */
135 static inline void watchdog_set_nowayout(struct watchdog_device
*wdd
, bool nowayout
)
138 set_bit(WDOG_NO_WAY_OUT
, &wdd
->status
);
141 /* Use the following function to stop the watchdog on reboot */
142 static inline void watchdog_stop_on_reboot(struct watchdog_device
*wdd
)
144 set_bit(WDOG_STOP_ON_REBOOT
, &wdd
->status
);
147 /* Use the following function to check if a timeout value is invalid */
148 static inline bool watchdog_timeout_invalid(struct watchdog_device
*wdd
, unsigned int t
)
151 * The timeout is invalid if
152 * - the requested value is larger than UINT_MAX / 1000
153 * (since internal calculations are done in milli-seconds),
155 * - the requested value is smaller than the configured minimum timeout,
157 * - a maximum hardware timeout is not configured, a maximum timeout
158 * is configured, and the requested value is larger than the
159 * configured maximum timeout.
161 return t
> UINT_MAX
/ 1000 || t
< wdd
->min_timeout
||
162 (!wdd
->max_hw_heartbeat_ms
&& wdd
->max_timeout
&&
163 t
> wdd
->max_timeout
);
166 /* Use the following functions to manipulate watchdog driver specific data */
167 static inline void watchdog_set_drvdata(struct watchdog_device
*wdd
, void *data
)
169 wdd
->driver_data
= data
;
172 static inline void *watchdog_get_drvdata(struct watchdog_device
*wdd
)
174 return wdd
->driver_data
;
177 /* drivers/watchdog/watchdog_core.c */
178 void watchdog_set_restart_priority(struct watchdog_device
*wdd
, int priority
);
179 extern int watchdog_init_timeout(struct watchdog_device
*wdd
,
180 unsigned int timeout_parm
, struct device
*dev
);
181 extern int watchdog_register_device(struct watchdog_device
*);
182 extern void watchdog_unregister_device(struct watchdog_device
*);
184 /* devres register variant */
185 int devm_watchdog_register_device(struct device
*dev
, struct watchdog_device
*);
187 #endif /* ifndef _LINUX_WATCHDOG_H */