1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright 2017 Google, Inc
4 */
5
6 #define LOG_CATEGORY UCLASS_WDT
7
8 #include <common.h>
9 #include <cyclic.h>
10 #include <dm.h>
11 #include <errno.h>
12 #include <hang.h>
13 #include <log.h>
14 #include <sysreset.h>
15 #include <time.h>
16 #include <wdt.h>
17 #include <asm/global_data.h>
18 #include <dm/device-internal.h>
19 #include <dm/lists.h>
20
21 DECLARE_GLOBAL_DATA_PTR;
22
23 #define WATCHDOG_TIMEOUT_SECS (CONFIG_WATCHDOG_TIMEOUT_MSECS / 1000)
24
25 struct wdt_priv {
26 /* Timeout, in seconds, to configure this device to. */
27 u32 timeout;
28 /*
29 * Time, in milliseconds, between calling the device's ->reset()
30 * method from watchdog_reset().
31 */
32 ulong reset_period;
33 /*
34 * Next time (as returned by get_timer(0)) to call
35 * ->reset().
36 */
37 ulong next_reset;
38 /* Whether watchdog_start() has been called on the device. */
39 bool running;
40 /* autostart */
41 bool autostart;
42
43 struct cyclic_info *cyclic;
44 };
45
wdt_cyclic(void * ctx)46 static void wdt_cyclic(void *ctx)
47 {
48 struct udevice *dev = ctx;
49 struct wdt_priv *priv;
50
51 if (!device_active(dev))
52 return;
53
54 priv = dev_get_uclass_priv(dev);
55 if (!priv->running)
56 return;
57
58 wdt_reset(dev);
59 }
60
init_watchdog_dev(struct udevice * dev)61 static void init_watchdog_dev(struct udevice *dev)
62 {
63 struct wdt_priv *priv;
64 int ret;
65
66 priv = dev_get_uclass_priv(dev);
67
68 if (IS_ENABLED(CONFIG_SYSRESET_WATCHDOG_AUTO)) {
69 ret = sysreset_register_wdt(dev);
70 if (ret)
71 printf("WDT: Failed to register %s for sysreset\n",
72 dev->name);
73 }
74
75 if (!priv->autostart) {
76 printf("WDT: Not starting %s\n", dev->name);
77 return;
78 }
79
80 ret = wdt_start(dev, priv->timeout * 1000, 0);
81 if (ret != 0) {
82 printf("WDT: Failed to start %s\n", dev->name);
83 return;
84 }
85 }
86
initr_watchdog(void)87 int initr_watchdog(void)
88 {
89 struct udevice *dev;
90 struct uclass *uc;
91 int ret;
92
93 ret = uclass_get(UCLASS_WDT, &uc);
94 if (ret) {
95 log_debug("Error getting UCLASS_WDT: %d\n", ret);
96 return 0;
97 }
98
99 uclass_foreach_dev(dev, uc) {
100 ret = device_probe(dev);
101 if (ret) {
102 log_debug("Error probing %s: %d\n", dev->name, ret);
103 continue;
104 }
105 init_watchdog_dev(dev);
106 }
107
108 return 0;
109 }
110
wdt_start(struct udevice * dev,u64 timeout_ms,ulong flags)111 int wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
112 {
113 const struct wdt_ops *ops = device_get_ops(dev);
114 int ret;
115
116 if (!ops->start)
117 return -ENOSYS;
118
119 ret = ops->start(dev, timeout_ms, flags);
120 if (ret == 0) {
121 struct wdt_priv *priv = dev_get_uclass_priv(dev);
122 char str[16];
123
124 priv->running = true;
125
126 memset(str, 0, 16);
127 if (IS_ENABLED(CONFIG_WATCHDOG)) {
128 /* Register the watchdog driver as a cyclic function */
129 priv->cyclic = cyclic_register(wdt_cyclic,
130 priv->reset_period * 1000,
131 dev->name, dev);
132 if (!priv->cyclic) {
133 printf("cyclic_register for %s failed\n",
134 dev->name);
135 return -ENODEV;
136 } else {
137 snprintf(str, 16, "every %ldms",
138 priv->reset_period);
139 }
140 }
141
142 printf("WDT: Started %s with%s servicing %s (%ds timeout)\n",
143 dev->name, IS_ENABLED(CONFIG_WATCHDOG) ? "" : "out",
144 str, priv->timeout);
145 }
146
147 return ret;
148 }
149
wdt_stop(struct udevice * dev)150 int wdt_stop(struct udevice *dev)
151 {
152 const struct wdt_ops *ops = device_get_ops(dev);
153 int ret;
154
155 if (!ops->stop)
156 return -ENOSYS;
157
158 ret = ops->stop(dev);
159 if (ret == 0) {
160 struct wdt_priv *priv = dev_get_uclass_priv(dev);
161
162 priv->running = false;
163 }
164
165 return ret;
166 }
167
wdt_stop_all(void)168 int wdt_stop_all(void)
169 {
170 struct wdt_priv *priv;
171 struct udevice *dev;
172 struct uclass *uc;
173 int ret, err;
174
175 ret = uclass_get(UCLASS_WDT, &uc);
176 if (ret)
177 return ret;
178
179 uclass_foreach_dev(dev, uc) {
180 if (!device_active(dev))
181 continue;
182 priv = dev_get_uclass_priv(dev);
183 if (!priv->running)
184 continue;
185 err = wdt_stop(dev);
186 if (!ret)
187 ret = err;
188 }
189
190 return ret;
191 }
192
wdt_reset(struct udevice * dev)193 int wdt_reset(struct udevice *dev)
194 {
195 const struct wdt_ops *ops = device_get_ops(dev);
196
197 if (!ops->reset)
198 return -ENOSYS;
199
200 return ops->reset(dev);
201 }
202
wdt_expire_now(struct udevice * dev,ulong flags)203 int wdt_expire_now(struct udevice *dev, ulong flags)
204 {
205 int ret = 0;
206 const struct wdt_ops *ops;
207
208 debug("WDT Resetting: %lu\n", flags);
209 ops = device_get_ops(dev);
210 if (ops->expire_now) {
211 return ops->expire_now(dev, flags);
212 } else {
213 ret = wdt_start(dev, 1, flags);
214
215 if (ret < 0)
216 return ret;
217
218 hang();
219 }
220
221 return ret;
222 }
223
224 #if defined(CONFIG_WATCHDOG)
225 /*
226 * Called by macro WATCHDOG_RESET. This function be called *very* early,
227 * so we need to make sure, that the watchdog driver is ready before using
228 * it in this function.
229 */
watchdog_reset(void)230 void watchdog_reset(void)
231 {
232 /*
233 * Empty function for now. The actual WDT handling is now done in
234 * the cyclic function instead.
235 */
236 }
237 #endif
238
wdt_post_bind(struct udevice * dev)239 static int wdt_post_bind(struct udevice *dev)
240 {
241 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
242 struct wdt_ops *ops = (struct wdt_ops *)device_get_ops(dev);
243 static int reloc_done;
244
245 if (!reloc_done) {
246 if (ops->start)
247 ops->start += gd->reloc_off;
248 if (ops->stop)
249 ops->stop += gd->reloc_off;
250 if (ops->reset)
251 ops->reset += gd->reloc_off;
252 if (ops->expire_now)
253 ops->expire_now += gd->reloc_off;
254
255 reloc_done++;
256 }
257 #endif
258 return 0;
259 }
260
wdt_pre_probe(struct udevice * dev)261 static int wdt_pre_probe(struct udevice *dev)
262 {
263 u32 timeout = WATCHDOG_TIMEOUT_SECS;
264 /*
265 * Reset every 1000ms, or however often is required as
266 * indicated by a hw_margin_ms property.
267 */
268 ulong reset_period = 1000;
269 bool autostart = IS_ENABLED(CONFIG_WATCHDOG_AUTOSTART);
270 struct wdt_priv *priv;
271
272 if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)) {
273 timeout = dev_read_u32_default(dev, "timeout-sec", timeout);
274 reset_period = dev_read_u32_default(dev, "hw_margin_ms",
275 4 * reset_period) / 4;
276 if (dev_read_bool(dev, "u-boot,noautostart"))
277 autostart = false;
278 else if (dev_read_bool(dev, "u-boot,autostart"))
279 autostart = true;
280 }
281 priv = dev_get_uclass_priv(dev);
282 priv->timeout = timeout;
283 priv->reset_period = reset_period;
284 priv->autostart = autostart;
285 /*
286 * Pretend this device was last reset "long" ago so the first
287 * watchdog_reset will actually call its ->reset method.
288 */
289 priv->next_reset = get_timer(0);
290
291 return 0;
292 }
293
294 UCLASS_DRIVER(wdt) = {
295 .id = UCLASS_WDT,
296 .name = "watchdog",
297 .flags = DM_UC_FLAG_SEQ_ALIAS,
298 .post_bind = wdt_post_bind,
299 .pre_probe = wdt_pre_probe,
300 .per_device_auto = sizeof(struct wdt_priv),
301 };
302