1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright 2017 Google, Inc
4 */
5
6 #include <common.h>
7 #include <dm.h>
8 #include <errno.h>
9 #include <hang.h>
10 #include <log.h>
11 #include <time.h>
12 #include <wdt.h>
13 #include <dm/device-internal.h>
14 #include <dm/lists.h>
15
16 DECLARE_GLOBAL_DATA_PTR;
17
18 #define WATCHDOG_TIMEOUT_SECS (CONFIG_WATCHDOG_TIMEOUT_MSECS / 1000)
19
20 /*
21 * Reset every 1000ms, or however often is required as indicated by a
22 * hw_margin_ms property.
23 */
24 static ulong reset_period = 1000;
25
initr_watchdog(void)26 int initr_watchdog(void)
27 {
28 u32 timeout = WATCHDOG_TIMEOUT_SECS;
29
30 /*
31 * Init watchdog: This will call the probe function of the
32 * watchdog driver, enabling the use of the device
33 */
34 if (uclass_get_device_by_seq(UCLASS_WDT, 0,
35 (struct udevice **)&gd->watchdog_dev)) {
36 debug("WDT: Not found by seq!\n");
37 if (uclass_get_device(UCLASS_WDT, 0,
38 (struct udevice **)&gd->watchdog_dev)) {
39 printf("WDT: Not found!\n");
40 return 0;
41 }
42 }
43
44 if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)) {
45 timeout = dev_read_u32_default(gd->watchdog_dev, "timeout-sec",
46 WATCHDOG_TIMEOUT_SECS);
47 reset_period = dev_read_u32_default(gd->watchdog_dev,
48 "hw_margin_ms",
49 4 * reset_period) / 4;
50 }
51
52 wdt_start(gd->watchdog_dev, timeout * 1000, 0);
53 gd->flags |= GD_FLG_WDT_READY;
54 printf("WDT: Started with%s servicing (%ds timeout)\n",
55 IS_ENABLED(CONFIG_WATCHDOG) ? "" : "out", timeout);
56
57 return 0;
58 }
59
wdt_start(struct udevice * dev,u64 timeout_ms,ulong flags)60 int wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
61 {
62 const struct wdt_ops *ops = device_get_ops(dev);
63
64 if (!ops->start)
65 return -ENOSYS;
66
67 return ops->start(dev, timeout_ms, flags);
68 }
69
wdt_stop(struct udevice * dev)70 int wdt_stop(struct udevice *dev)
71 {
72 const struct wdt_ops *ops = device_get_ops(dev);
73
74 if (!ops->stop)
75 return -ENOSYS;
76
77 return ops->stop(dev);
78 }
79
wdt_reset(struct udevice * dev)80 int wdt_reset(struct udevice *dev)
81 {
82 const struct wdt_ops *ops = device_get_ops(dev);
83
84 if (!ops->reset)
85 return -ENOSYS;
86
87 return ops->reset(dev);
88 }
89
wdt_expire_now(struct udevice * dev,ulong flags)90 int wdt_expire_now(struct udevice *dev, ulong flags)
91 {
92 int ret = 0;
93 const struct wdt_ops *ops;
94
95 debug("WDT Resetting: %lu\n", flags);
96 ops = device_get_ops(dev);
97 if (ops->expire_now) {
98 return ops->expire_now(dev, flags);
99 } else {
100 if (!ops->start)
101 return -ENOSYS;
102
103 ret = ops->start(dev, 1, flags);
104 if (ret < 0)
105 return ret;
106
107 hang();
108 }
109
110 return ret;
111 }
112
113 #if defined(CONFIG_WATCHDOG)
114 /*
115 * Called by macro WATCHDOG_RESET. This function be called *very* early,
116 * so we need to make sure, that the watchdog driver is ready before using
117 * it in this function.
118 */
watchdog_reset(void)119 void watchdog_reset(void)
120 {
121 static ulong next_reset;
122 ulong now;
123
124 /* Exit if GD is not ready or watchdog is not initialized yet */
125 if (!gd || !(gd->flags & GD_FLG_WDT_READY))
126 return;
127
128 /* Do not reset the watchdog too often */
129 now = get_timer(0);
130 if (time_after(now, next_reset)) {
131 next_reset = now + reset_period;
132 wdt_reset(gd->watchdog_dev);
133 }
134 }
135 #endif
136
wdt_post_bind(struct udevice * dev)137 static int wdt_post_bind(struct udevice *dev)
138 {
139 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
140 struct wdt_ops *ops = (struct wdt_ops *)device_get_ops(dev);
141 static int reloc_done;
142
143 if (!reloc_done) {
144 if (ops->start)
145 ops->start += gd->reloc_off;
146 if (ops->stop)
147 ops->stop += gd->reloc_off;
148 if (ops->reset)
149 ops->reset += gd->reloc_off;
150 if (ops->expire_now)
151 ops->expire_now += gd->reloc_off;
152
153 reloc_done++;
154 }
155 #endif
156 return 0;
157 }
158
159 UCLASS_DRIVER(wdt) = {
160 .id = UCLASS_WDT,
161 .name = "watchdog",
162 .flags = DM_UC_FLAG_SEQ_ALIAS,
163 .post_bind = wdt_post_bind,
164 };
165