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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | /* |
3 | * Generic watchdog defines. Derived from.. | |
4 | * | |
5 | * Berkshire PC Watchdog Defines | |
6 | * by Ken Hollis <khollis@bitgate.com> | |
7 | * | |
8 | */ | |
1da177e4 LT |
9 | #ifndef _LINUX_WATCHDOG_H |
10 | #define _LINUX_WATCHDOG_H | |
11 | ||
4bfdf378 | 12 | |
ff0b3cd4 | 13 | #include <linux/bitops.h> |
45f5fed3 | 14 | #include <linux/cdev.h> |
664a3923 GR |
15 | #include <linux/device.h> |
16 | #include <linux/kernel.h> | |
2165bf52 | 17 | #include <linux/notifier.h> |
607ca46e | 18 | #include <uapi/linux/watchdog.h> |
4bfdf378 | 19 | |
43316044 WVS |
20 | struct watchdog_ops; |
21 | struct watchdog_device; | |
b4ffb190 | 22 | struct watchdog_core_data; |
ff84136c | 23 | struct watchdog_governor; |
43316044 WVS |
24 | |
25 | /** struct watchdog_ops - The watchdog-devices operations | |
26 | * | |
27 | * @owner: The module owner. | |
28 | * @start: The routine for starting the watchdog device. | |
29 | * @stop: The routine for stopping the watchdog device. | |
30 | * @ping: The routine that sends a keepalive ping to the watchdog device. | |
2fa03560 | 31 | * @status: The routine that shows the status of the watchdog device. |
760d2800 | 32 | * @set_timeout:The routine for setting the watchdog devices timeout value (in seconds). |
df044e02 | 33 | * @set_pretimeout:The routine for setting the watchdog devices pretimeout. |
760d2800 | 34 | * @get_timeleft:The routine that gets the time left before a reset (in seconds). |
2165bf52 | 35 | * @restart: The routine for restarting the machine. |
78d88fc0 | 36 | * @ioctl: The routines that handles extra ioctl calls. |
43316044 WVS |
37 | * |
38 | * The watchdog_ops structure contains a list of low-level operations | |
39 | * that control a watchdog device. It also contains the module that owns | |
40 | * these operations. The start and stop function are mandatory, all other | |
80220fa7 | 41 | * functions are optional. |
43316044 WVS |
42 | */ |
43 | struct watchdog_ops { | |
44 | struct module *owner; | |
45 | /* mandatory operations */ | |
46 | int (*start)(struct watchdog_device *); | |
47 | int (*stop)(struct watchdog_device *); | |
48 | /* optional operations */ | |
49 | int (*ping)(struct watchdog_device *); | |
2fa03560 | 50 | unsigned int (*status)(struct watchdog_device *); |
014d694e | 51 | int (*set_timeout)(struct watchdog_device *, unsigned int); |
df044e02 | 52 | int (*set_pretimeout)(struct watchdog_device *, unsigned int); |
fd7b673c | 53 | unsigned int (*get_timeleft)(struct watchdog_device *); |
4d8b229d | 54 | int (*restart)(struct watchdog_device *, unsigned long, void *); |
78d88fc0 | 55 | long (*ioctl)(struct watchdog_device *, unsigned int, unsigned long); |
43316044 WVS |
56 | }; |
57 | ||
58 | /** struct watchdog_device - The structure that defines a watchdog device | |
59 | * | |
45f5fed3 | 60 | * @id: The watchdog's ID. (Allocated by watchdog_register_device) |
d6b469d9 | 61 | * @parent: The parent bus device |
faa58475 GR |
62 | * @groups: List of sysfs attribute groups to create when creating the |
63 | * watchdog device. | |
43316044 WVS |
64 | * @info: Pointer to a watchdog_info structure. |
65 | * @ops: Pointer to the list of watchdog operations. | |
ff84136c | 66 | * @gov: Pointer to watchdog pretimeout governor. |
2fa03560 | 67 | * @bootstatus: Status of the watchdog device at boot. |
760d2800 | 68 | * @timeout: The watchdog devices timeout value (in seconds). |
df044e02 | 69 | * @pretimeout: The watchdog devices pre_timeout value. |
760d2800 | 70 | * @min_timeout:The watchdog devices minimum timeout value (in seconds). |
664a3923 GR |
71 | * @max_timeout:The watchdog devices maximum timeout value (in seconds) |
72 | * as configurable from user space. Only relevant if | |
73 | * max_hw_heartbeat_ms is not provided. | |
15013ad8 | 74 | * @min_hw_heartbeat_ms: |
f9f535c1 GR |
75 | * Hardware limit for minimum time between heartbeats, |
76 | * in milli-seconds. | |
664a3923 GR |
77 | * @max_hw_heartbeat_ms: |
78 | * Hardware limit for maximum timeout, in milli-seconds. | |
79 | * Replaces max_timeout if specified. | |
e1313196 | 80 | * @reboot_nb: The notifier block to stop watchdog on reboot. |
2165bf52 | 81 | * @restart_nb: The notifier block to register a restart function. |
b4ffb190 GR |
82 | * @driver_data:Pointer to the drivers private data. |
83 | * @wd_data: Pointer to watchdog core internal data. | |
43316044 | 84 | * @status: Field that contains the devices internal status bits. |
664a3923 GR |
85 | * @deferred: Entry in wtd_deferred_reg_list which is used to |
86 | * register early initialized watchdogs. | |
43316044 WVS |
87 | * |
88 | * The watchdog_device structure contains all information about a | |
89 | * watchdog timer device. | |
90 | * | |
91 | * The driver-data field may not be accessed directly. It must be accessed | |
92 | * via the watchdog_set_drvdata and watchdog_get_drvdata helpers. | |
93 | */ | |
94 | struct watchdog_device { | |
45f5fed3 | 95 | int id; |
d6b469d9 | 96 | struct device *parent; |
faa58475 | 97 | const struct attribute_group **groups; |
43316044 WVS |
98 | const struct watchdog_info *info; |
99 | const struct watchdog_ops *ops; | |
ff84136c | 100 | const struct watchdog_governor *gov; |
2fa03560 | 101 | unsigned int bootstatus; |
014d694e | 102 | unsigned int timeout; |
df044e02 | 103 | unsigned int pretimeout; |
3f43f68e WVS |
104 | unsigned int min_timeout; |
105 | unsigned int max_timeout; | |
15013ad8 | 106 | unsigned int min_hw_heartbeat_ms; |
664a3923 | 107 | unsigned int max_hw_heartbeat_ms; |
e1313196 | 108 | struct notifier_block reboot_nb; |
2165bf52 | 109 | struct notifier_block restart_nb; |
43316044 | 110 | void *driver_data; |
b4ffb190 | 111 | struct watchdog_core_data *wd_data; |
43316044 WVS |
112 | unsigned long status; |
113 | /* Bit numbers for status flags */ | |
234445b4 | 114 | #define WDOG_ACTIVE 0 /* Is the watchdog running/active */ |
b4ffb190 GR |
115 | #define WDOG_NO_WAY_OUT 1 /* Is 'nowayout' feature set ? */ |
116 | #define WDOG_STOP_ON_REBOOT 2 /* Should be stopped on reboot */ | |
ee142889 | 117 | #define WDOG_HW_RUNNING 3 /* True if HW watchdog running */ |
bb292ac1 | 118 | #define WDOG_STOP_ON_UNREGISTER 4 /* Should be stopped on unregister */ |
ef90174f | 119 | struct list_head deferred; |
43316044 WVS |
120 | }; |
121 | ||
4846e378 UKK |
122 | #define WATCHDOG_NOWAYOUT IS_BUILTIN(CONFIG_WATCHDOG_NOWAYOUT) |
123 | #define WATCHDOG_NOWAYOUT_INIT_STATUS (WATCHDOG_NOWAYOUT << WDOG_NO_WAY_OUT) | |
ff0b3cd4 | 124 | |
48fc7f7e | 125 | /* Use the following function to check whether or not the watchdog is active */ |
257f8c4a VK |
126 | static inline bool watchdog_active(struct watchdog_device *wdd) |
127 | { | |
128 | return test_bit(WDOG_ACTIVE, &wdd->status); | |
129 | } | |
130 | ||
ee142889 GR |
131 | /* |
132 | * Use the following function to check whether or not the hardware watchdog | |
133 | * is running | |
134 | */ | |
135 | static inline bool watchdog_hw_running(struct watchdog_device *wdd) | |
136 | { | |
137 | return test_bit(WDOG_HW_RUNNING, &wdd->status); | |
138 | } | |
139 | ||
ff0b3cd4 | 140 | /* Use the following function to set the nowayout feature */ |
86a1e189 | 141 | static inline void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout) |
ff0b3cd4 WVS |
142 | { |
143 | if (nowayout) | |
144 | set_bit(WDOG_NO_WAY_OUT, &wdd->status); | |
145 | } | |
146 | ||
e1313196 DR |
147 | /* Use the following function to stop the watchdog on reboot */ |
148 | static inline void watchdog_stop_on_reboot(struct watchdog_device *wdd) | |
149 | { | |
150 | set_bit(WDOG_STOP_ON_REBOOT, &wdd->status); | |
151 | } | |
152 | ||
bb292ac1 GR |
153 | /* Use the following function to stop the watchdog when unregistering it */ |
154 | static inline void watchdog_stop_on_unregister(struct watchdog_device *wdd) | |
155 | { | |
156 | set_bit(WDOG_STOP_ON_UNREGISTER, &wdd->status); | |
157 | } | |
158 | ||
3048253e FP |
159 | /* Use the following function to check if a timeout value is invalid */ |
160 | static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigned int t) | |
161 | { | |
1e935949 GR |
162 | /* |
163 | * The timeout is invalid if | |
664a3923 GR |
164 | * - the requested value is larger than UINT_MAX / 1000 |
165 | * (since internal calculations are done in milli-seconds), | |
166 | * or | |
1e935949 GR |
167 | * - the requested value is smaller than the configured minimum timeout, |
168 | * or | |
664a3923 GR |
169 | * - a maximum hardware timeout is not configured, a maximum timeout |
170 | * is configured, and the requested value is larger than the | |
171 | * configured maximum timeout. | |
1e935949 | 172 | */ |
664a3923 GR |
173 | return t > UINT_MAX / 1000 || t < wdd->min_timeout || |
174 | (!wdd->max_hw_heartbeat_ms && wdd->max_timeout && | |
175 | t > wdd->max_timeout); | |
3048253e FP |
176 | } |
177 | ||
df044e02 WS |
178 | /* Use the following function to check if a pretimeout value is invalid */ |
179 | static inline bool watchdog_pretimeout_invalid(struct watchdog_device *wdd, | |
180 | unsigned int t) | |
181 | { | |
182 | return t && wdd->timeout && t >= wdd->timeout; | |
183 | } | |
184 | ||
43316044 WVS |
185 | /* Use the following functions to manipulate watchdog driver specific data */ |
186 | static inline void watchdog_set_drvdata(struct watchdog_device *wdd, void *data) | |
187 | { | |
188 | wdd->driver_data = data; | |
189 | } | |
190 | ||
191 | static inline void *watchdog_get_drvdata(struct watchdog_device *wdd) | |
192 | { | |
193 | return wdd->driver_data; | |
194 | } | |
195 | ||
ff84136c VZ |
196 | /* Use the following functions to report watchdog pretimeout event */ |
197 | #if IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_GOV) | |
198 | void watchdog_notify_pretimeout(struct watchdog_device *wdd); | |
199 | #else | |
200 | static inline void watchdog_notify_pretimeout(struct watchdog_device *wdd) | |
201 | { | |
202 | pr_alert("watchdog%d: pretimeout event\n", wdd->id); | |
203 | } | |
204 | #endif | |
205 | ||
cf13a84d | 206 | /* drivers/watchdog/watchdog_core.c */ |
2165bf52 | 207 | void watchdog_set_restart_priority(struct watchdog_device *wdd, int priority); |
3048253e FP |
208 | extern int watchdog_init_timeout(struct watchdog_device *wdd, |
209 | unsigned int timeout_parm, struct device *dev); | |
43316044 WVS |
210 | extern int watchdog_register_device(struct watchdog_device *); |
211 | extern void watchdog_unregister_device(struct watchdog_device *); | |
212 | ||
83fbae5a NA |
213 | /* devres register variant */ |
214 | int devm_watchdog_register_device(struct device *dev, struct watchdog_device *); | |
215 | ||
1da177e4 | 216 | #endif /* ifndef _LINUX_WATCHDOG_H */ |