]>
Commit | Line | Data |
---|---|---|
83d290c5 | 1 | /* SPDX-License-Identifier: GPL-2.0+ */ |
0753bc2d | 2 | /* |
3 | * Copyright 2017 Google, Inc | |
0753bc2d | 4 | */ |
5 | ||
6 | #ifndef _WDT_H_ | |
7 | #define _WDT_H_ | |
8 | ||
06985289 SR |
9 | #include <dm.h> |
10 | #include <dm/read.h> | |
11 | ||
0753bc2d | 12 | /* |
13 | * Implement a simple watchdog uclass. Watchdog is basically a timer that | |
14 | * is used to detect or recover from malfunction. During normal operation | |
15 | * the watchdog would be regularly reset to prevent it from timing out. | |
16 | * If, due to a hardware fault or program error, the computer fails to reset | |
17 | * the watchdog, the timer will elapse and generate a timeout signal. | |
18 | * The timeout signal is used to initiate corrective action or actions, | |
19 | * which typically include placing the system in a safe, known state. | |
20 | */ | |
21 | ||
22 | /* | |
23 | * Start the timer | |
24 | * | |
25 | * @dev: WDT Device | |
ffdec300 | 26 | * @timeout_ms: Number of ticks (milliseconds) before timer expires |
0753bc2d | 27 | * @flags: Driver specific flags. This might be used to specify |
28 | * which action needs to be executed when the timer expires | |
29 | * @return: 0 if OK, -ve on error | |
30 | */ | |
ffdec300 | 31 | int wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags); |
0753bc2d | 32 | |
33 | /* | |
34 | * Stop the timer, thus disabling the Watchdog. Use wdt_start to start it again. | |
35 | * | |
36 | * @dev: WDT Device | |
37 | * @return: 0 if OK, -ve on error | |
38 | */ | |
39 | int wdt_stop(struct udevice *dev); | |
40 | ||
41 | /* | |
42 | * Reset the timer, typically restoring the counter to | |
43 | * the value configured by start() | |
44 | * | |
45 | * @dev: WDT Device | |
46 | * @return: 0 if OK, -ve on error | |
47 | */ | |
48 | int wdt_reset(struct udevice *dev); | |
49 | ||
50 | /* | |
51 | * Expire the timer, thus executing its action immediately. | |
52 | * This is typically used to reset the board or peripherals. | |
53 | * | |
54 | * @dev: WDT Device | |
55 | * @flags: Driver specific flags | |
56 | * @return 0 if OK -ve on error. If wdt action is system reset, | |
57 | * this function may never return. | |
58 | */ | |
59 | int wdt_expire_now(struct udevice *dev, ulong flags); | |
60 | ||
61 | /* | |
62 | * struct wdt_ops - Driver model wdt operations | |
63 | * | |
64 | * The uclass interface is implemented by all wdt devices which use | |
65 | * driver model. | |
66 | */ | |
67 | struct wdt_ops { | |
68 | /* | |
69 | * Start the timer | |
70 | * | |
71 | * @dev: WDT Device | |
ffdec300 | 72 | * @timeout_ms: Number of ticks (milliseconds) before the timer expires |
0753bc2d | 73 | * @flags: Driver specific flags. This might be used to specify |
74 | * which action needs to be executed when the timer expires | |
75 | * @return: 0 if OK, -ve on error | |
76 | */ | |
ffdec300 | 77 | int (*start)(struct udevice *dev, u64 timeout_ms, ulong flags); |
0753bc2d | 78 | /* |
79 | * Stop the timer | |
80 | * | |
81 | * @dev: WDT Device | |
82 | * @return: 0 if OK, -ve on error | |
83 | */ | |
84 | int (*stop)(struct udevice *dev); | |
85 | /* | |
86 | * Reset the timer, typically restoring the counter to | |
87 | * the value configured by start() | |
88 | * | |
89 | * @dev: WDT Device | |
90 | * @return: 0 if OK, -ve on error | |
91 | */ | |
92 | int (*reset)(struct udevice *dev); | |
93 | /* | |
94 | * Expire the timer, thus executing the action immediately (optional) | |
95 | * | |
96 | * If this function is not provided, a default implementation | |
97 | * will be used, which sets the counter to 1 | |
98 | * and waits forever. This is good enough for system level | |
99 | * reset, where the function is not expected to return, but might not be | |
100 | * good enough for other use cases. | |
101 | * | |
102 | * @dev: WDT Device | |
103 | * @flags: Driver specific flags | |
104 | * @return 0 if OK -ve on error. May not return. | |
105 | */ | |
106 | int (*expire_now)(struct udevice *dev, ulong flags); | |
107 | }; | |
108 | ||
6874cb72 | 109 | #if CONFIG_IS_ENABLED(WDT) |
06985289 SR |
110 | #ifndef CONFIG_WATCHDOG_TIMEOUT_MSECS |
111 | #define CONFIG_WATCHDOG_TIMEOUT_MSECS (60 * 1000) | |
112 | #endif | |
113 | #define WATCHDOG_TIMEOUT_SECS (CONFIG_WATCHDOG_TIMEOUT_MSECS / 1000) | |
114 | ||
115 | static inline int initr_watchdog(void) | |
116 | { | |
117 | u32 timeout = WATCHDOG_TIMEOUT_SECS; | |
118 | ||
119 | /* | |
120 | * Init watchdog: This will call the probe function of the | |
121 | * watchdog driver, enabling the use of the device | |
122 | */ | |
123 | if (uclass_get_device_by_seq(UCLASS_WDT, 0, | |
124 | (struct udevice **)&gd->watchdog_dev)) { | |
125 | debug("WDT: Not found by seq!\n"); | |
126 | if (uclass_get_device(UCLASS_WDT, 0, | |
127 | (struct udevice **)&gd->watchdog_dev)) { | |
128 | printf("WDT: Not found!\n"); | |
129 | return 0; | |
130 | } | |
131 | } | |
132 | ||
133 | if (CONFIG_IS_ENABLED(OF_CONTROL)) { | |
134 | timeout = dev_read_u32_default(gd->watchdog_dev, "timeout-sec", | |
135 | WATCHDOG_TIMEOUT_SECS); | |
136 | } | |
137 | ||
138 | wdt_start(gd->watchdog_dev, timeout * 1000, 0); | |
139 | gd->flags |= GD_FLG_WDT_READY; | |
140 | printf("WDT: Started with%s servicing (%ds timeout)\n", | |
141 | IS_ENABLED(CONFIG_WATCHDOG) ? "" : "out", timeout); | |
142 | ||
143 | return 0; | |
144 | } | |
145 | #endif | |
146 | ||
0753bc2d | 147 | #endif /* _WDT_H_ */ |