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 <asm/global_data.h>
14 #include <dm/device-internal.h>
15 #include <dm/lists.h>
16
17 DECLARE_GLOBAL_DATA_PTR;
18
19 #define WATCHDOG_TIMEOUT_SECS (CONFIG_WATCHDOG_TIMEOUT_MSECS / 1000)
20
21 /*
22 * Reset every 1000ms, or however often is required as indicated by a
23 * hw_margin_ms property.
24 */
25 static ulong reset_period = 1000;
26
initr_watchdog(void)27 int initr_watchdog(void)
28 {
29 u32 timeout = WATCHDOG_TIMEOUT_SECS;
30 int ret;
31
32 /*
33 * Init watchdog: This will call the probe function of the
34 * watchdog driver, enabling the use of the device
35 */
36 if (uclass_get_device_by_seq(UCLASS_WDT, 0,
37 (struct udevice **)&gd->watchdog_dev)) {
38 debug("WDT: Not found by seq!\n");
39 if (uclass_get_device(UCLASS_WDT, 0,
40 (struct udevice **)&gd->watchdog_dev)) {
41 printf("WDT: Not found!\n");
42 return 0;
43 }
44 }
45
46 if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)) {
47 timeout = dev_read_u32_default(gd->watchdog_dev, "timeout-sec",
48 WATCHDOG_TIMEOUT_SECS);
49 reset_period = dev_read_u32_default(gd->watchdog_dev,
50 "hw_margin_ms",
51 4 * reset_period) / 4;
52 }
53
54 if (!CONFIG_IS_ENABLED(WATCHDOG_AUTOSTART)) {
55 printf("WDT: Not starting\n");
56 return 0;
57 }
58
59 ret = wdt_start(gd->watchdog_dev, timeout * 1000, 0);
60 if (ret != 0) {
61 printf("WDT: Failed to start\n");
62 return 0;
63 }
64
65 printf("WDT: Started with%s servicing (%ds timeout)\n",
66 IS_ENABLED(CONFIG_WATCHDOG) ? "" : "out", timeout);
67
68 return 0;
69 }
70
wdt_start(struct udevice * dev,u64 timeout_ms,ulong flags)71 int wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
72 {
73 const struct wdt_ops *ops = device_get_ops(dev);
74 int ret;
75
76 if (!ops->start)
77 return -ENOSYS;
78
79 ret = ops->start(dev, timeout_ms, flags);
80 if (ret == 0)
81 gd->flags |= GD_FLG_WDT_READY;
82
83 return ret;
84 }
85
wdt_stop(struct udevice * dev)86 int wdt_stop(struct udevice *dev)
87 {
88 const struct wdt_ops *ops = device_get_ops(dev);
89 int ret;
90
91 if (!ops->stop)
92 return -ENOSYS;
93
94 ret = ops->stop(dev);
95 if (ret == 0)
96 gd->flags &= ~GD_FLG_WDT_READY;
97
98 return ret;
99 }
100
wdt_reset(struct udevice * dev)101 int wdt_reset(struct udevice *dev)
102 {
103 const struct wdt_ops *ops = device_get_ops(dev);
104
105 if (!ops->reset)
106 return -ENOSYS;
107
108 return ops->reset(dev);
109 }
110
wdt_expire_now(struct udevice * dev,ulong flags)111 int wdt_expire_now(struct udevice *dev, ulong flags)
112 {
113 int ret = 0;
114 const struct wdt_ops *ops;
115
116 debug("WDT Resetting: %lu\n", flags);
117 ops = device_get_ops(dev);
118 if (ops->expire_now) {
119 return ops->expire_now(dev, flags);
120 } else {
121 if (!ops->start)
122 return -ENOSYS;
123
124 ret = ops->start(dev, 1, flags);
125 if (ret < 0)
126 return ret;
127
128 hang();
129 }
130
131 return ret;
132 }
133
134 #if defined(CONFIG_WATCHDOG)
135 /*
136 * Called by macro WATCHDOG_RESET. This function be called *very* early,
137 * so we need to make sure, that the watchdog driver is ready before using
138 * it in this function.
139 */
watchdog_reset(void)140 void watchdog_reset(void)
141 {
142 static ulong next_reset;
143 ulong now;
144
145 /* Exit if GD is not ready or watchdog is not initialized yet */
146 if (!gd || !(gd->flags & GD_FLG_WDT_READY))
147 return;
148
149 /* Do not reset the watchdog too often */
150 now = get_timer(0);
151 if (time_after_eq(now, next_reset)) {
152 next_reset = now + reset_period;
153 wdt_reset(gd->watchdog_dev);
154 }
155 }
156 #endif
157
wdt_post_bind(struct udevice * dev)158 static int wdt_post_bind(struct udevice *dev)
159 {
160 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
161 struct wdt_ops *ops = (struct wdt_ops *)device_get_ops(dev);
162 static int reloc_done;
163
164 if (!reloc_done) {
165 if (ops->start)
166 ops->start += gd->reloc_off;
167 if (ops->stop)
168 ops->stop += gd->reloc_off;
169 if (ops->reset)
170 ops->reset += gd->reloc_off;
171 if (ops->expire_now)
172 ops->expire_now += gd->reloc_off;
173
174 reloc_done++;
175 }
176 #endif
177 return 0;
178 }
179
180 UCLASS_DRIVER(wdt) = {
181 .id = UCLASS_WDT,
182 .name = "watchdog",
183 .flags = DM_UC_FLAG_SEQ_ALIAS,
184 .post_bind = wdt_post_bind,
185 };
186