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Commit | Line | Data |
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75722d39 BH |
1 | /* |
2 | * Windfarm PowerMac thermal control. Core | |
3 | * | |
4 | * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp. | |
5 | * <benh@kernel.crashing.org> | |
6 | * | |
7 | * Released under the term of the GNU GPL v2. | |
8 | * | |
9 | * This core code tracks the list of sensors & controls, register | |
10 | * clients, and holds the kernel thread used for control. | |
11 | * | |
12 | * TODO: | |
13 | * | |
14 | * Add some information about sensor/control type and data format to | |
15 | * sensors/controls, and have the sysfs attribute stuff be moved | |
16 | * generically here instead of hard coded in the platform specific | |
17 | * driver as it us currently | |
18 | * | |
19 | * This however requires solving some annoying lifetime issues with | |
20 | * sysfs which doesn't seem to have lifetime rules for struct attribute, | |
21 | * I may have to create full features kobjects for every sensor/control | |
22 | * instead which is a bit of an overkill imho | |
23 | */ | |
24 | ||
25 | #include <linux/types.h> | |
26 | #include <linux/errno.h> | |
27 | #include <linux/kernel.h> | |
28 | #include <linux/init.h> | |
29 | #include <linux/spinlock.h> | |
75722d39 BH |
30 | #include <linux/kthread.h> |
31 | #include <linux/jiffies.h> | |
32 | #include <linux/reboot.h> | |
33 | #include <linux/device.h> | |
34 | #include <linux/platform_device.h> | |
837e9594 | 35 | #include <linux/mutex.h> |
7dfb7103 | 36 | #include <linux/freezer.h> |
75722d39 | 37 | |
b55fafc5 BH |
38 | #include <asm/prom.h> |
39 | ||
75722d39 BH |
40 | #include "windfarm.h" |
41 | ||
42 | #define VERSION "0.2" | |
43 | ||
44 | #undef DEBUG | |
45 | ||
46 | #ifdef DEBUG | |
47 | #define DBG(args...) printk(args) | |
48 | #else | |
49 | #define DBG(args...) do { } while(0) | |
50 | #endif | |
51 | ||
52 | static LIST_HEAD(wf_controls); | |
53 | static LIST_HEAD(wf_sensors); | |
837e9594 | 54 | static DEFINE_MUTEX(wf_lock); |
e041c683 | 55 | static BLOCKING_NOTIFIER_HEAD(wf_client_list); |
75722d39 BH |
56 | static int wf_client_count; |
57 | static unsigned int wf_overtemp; | |
58 | static unsigned int wf_overtemp_counter; | |
59 | struct task_struct *wf_thread; | |
60 | ||
ac171c46 BH |
61 | static struct platform_device wf_platform_device = { |
62 | .name = "windfarm", | |
63 | }; | |
64 | ||
75722d39 BH |
65 | /* |
66 | * Utilities & tick thread | |
67 | */ | |
68 | ||
69 | static inline void wf_notify(int event, void *param) | |
70 | { | |
e041c683 | 71 | blocking_notifier_call_chain(&wf_client_list, event, param); |
75722d39 BH |
72 | } |
73 | ||
74 | int wf_critical_overtemp(void) | |
75 | { | |
76 | static char * critical_overtemp_path = "/sbin/critical_overtemp"; | |
77 | char *argv[] = { critical_overtemp_path, NULL }; | |
78 | static char *envp[] = { "HOME=/", | |
79 | "TERM=linux", | |
80 | "PATH=/sbin:/usr/sbin:/bin:/usr/bin", | |
81 | NULL }; | |
82 | ||
86313c48 JF |
83 | return call_usermodehelper(critical_overtemp_path, |
84 | argv, envp, UMH_WAIT_EXEC); | |
75722d39 BH |
85 | } |
86 | EXPORT_SYMBOL_GPL(wf_critical_overtemp); | |
87 | ||
88 | static int wf_thread_func(void *data) | |
89 | { | |
90 | unsigned long next, delay; | |
91 | ||
92 | next = jiffies; | |
93 | ||
94 | DBG("wf: thread started\n"); | |
95 | ||
83144186 | 96 | set_freezable(); |
75722d39 | 97 | while(!kthread_should_stop()) { |
75722d39 BH |
98 | if (time_after_eq(jiffies, next)) { |
99 | wf_notify(WF_EVENT_TICK, NULL); | |
100 | if (wf_overtemp) { | |
101 | wf_overtemp_counter++; | |
102 | /* 10 seconds overtemp, notify userland */ | |
103 | if (wf_overtemp_counter > 10) | |
104 | wf_critical_overtemp(); | |
105 | /* 30 seconds, shutdown */ | |
106 | if (wf_overtemp_counter > 30) { | |
107 | printk(KERN_ERR "windfarm: Overtemp " | |
108 | "for more than 30" | |
109 | " seconds, shutting down\n"); | |
110 | machine_power_off(); | |
111 | } | |
112 | } | |
113 | next += HZ; | |
114 | } | |
115 | ||
116 | delay = next - jiffies; | |
117 | if (delay <= HZ) | |
118 | schedule_timeout_interruptible(delay); | |
119 | ||
1ed2ddf3 JB |
120 | /* there should be no non-suspend signal, but oh well */ |
121 | if (signal_pending(current) && !try_to_freeze()) { | |
75722d39 BH |
122 | printk(KERN_WARNING "windfarm: thread got sigl !\n"); |
123 | break; | |
124 | } | |
125 | } | |
126 | ||
127 | DBG("wf: thread stopped\n"); | |
128 | ||
129 | return 0; | |
130 | } | |
131 | ||
132 | static void wf_start_thread(void) | |
133 | { | |
134 | wf_thread = kthread_run(wf_thread_func, NULL, "kwindfarm"); | |
135 | if (IS_ERR(wf_thread)) { | |
136 | printk(KERN_ERR "windfarm: failed to create thread,err %ld\n", | |
137 | PTR_ERR(wf_thread)); | |
138 | wf_thread = NULL; | |
139 | } | |
140 | } | |
141 | ||
142 | ||
143 | static void wf_stop_thread(void) | |
144 | { | |
145 | if (wf_thread) | |
146 | kthread_stop(wf_thread); | |
147 | wf_thread = NULL; | |
148 | } | |
149 | ||
150 | /* | |
151 | * Controls | |
152 | */ | |
153 | ||
154 | static void wf_control_release(struct kref *kref) | |
155 | { | |
156 | struct wf_control *ct = container_of(kref, struct wf_control, ref); | |
157 | ||
158 | DBG("wf: Deleting control %s\n", ct->name); | |
159 | ||
160 | if (ct->ops && ct->ops->release) | |
161 | ct->ops->release(ct); | |
162 | else | |
163 | kfree(ct); | |
164 | } | |
165 | ||
ac171c46 BH |
166 | static ssize_t wf_show_control(struct device *dev, |
167 | struct device_attribute *attr, char *buf) | |
168 | { | |
169 | struct wf_control *ctrl = container_of(attr, struct wf_control, attr); | |
170 | s32 val = 0; | |
171 | int err; | |
172 | ||
173 | err = ctrl->ops->get_value(ctrl, &val); | |
174 | if (err < 0) | |
175 | return err; | |
176 | return sprintf(buf, "%d\n", val); | |
177 | } | |
178 | ||
179 | /* This is really only for debugging... */ | |
180 | static ssize_t wf_store_control(struct device *dev, | |
181 | struct device_attribute *attr, | |
182 | const char *buf, size_t count) | |
183 | { | |
184 | struct wf_control *ctrl = container_of(attr, struct wf_control, attr); | |
185 | int val; | |
186 | int err; | |
187 | char *endp; | |
188 | ||
189 | val = simple_strtoul(buf, &endp, 0); | |
190 | while (endp < buf + count && (*endp == ' ' || *endp == '\n')) | |
191 | ++endp; | |
192 | if (endp - buf < count) | |
193 | return -EINVAL; | |
194 | err = ctrl->ops->set_value(ctrl, val); | |
195 | if (err < 0) | |
196 | return err; | |
197 | return count; | |
198 | } | |
199 | ||
75722d39 BH |
200 | int wf_register_control(struct wf_control *new_ct) |
201 | { | |
202 | struct wf_control *ct; | |
203 | ||
837e9594 | 204 | mutex_lock(&wf_lock); |
75722d39 BH |
205 | list_for_each_entry(ct, &wf_controls, link) { |
206 | if (!strcmp(ct->name, new_ct->name)) { | |
207 | printk(KERN_WARNING "windfarm: trying to register" | |
208 | " duplicate control %s\n", ct->name); | |
837e9594 | 209 | mutex_unlock(&wf_lock); |
75722d39 BH |
210 | return -EEXIST; |
211 | } | |
212 | } | |
213 | kref_init(&new_ct->ref); | |
214 | list_add(&new_ct->link, &wf_controls); | |
215 | ||
ac171c46 | 216 | new_ct->attr.attr.name = new_ct->name; |
ac171c46 BH |
217 | new_ct->attr.attr.mode = 0644; |
218 | new_ct->attr.show = wf_show_control; | |
219 | new_ct->attr.store = wf_store_control; | |
ccd308f0 SR |
220 | if (device_create_file(&wf_platform_device.dev, &new_ct->attr)) |
221 | printk(KERN_WARNING "windfarm: device_create_file failed" | |
222 | " for %s\n", new_ct->name); | |
223 | /* the subsystem still does useful work without the file */ | |
ac171c46 | 224 | |
75722d39 BH |
225 | DBG("wf: Registered control %s\n", new_ct->name); |
226 | ||
227 | wf_notify(WF_EVENT_NEW_CONTROL, new_ct); | |
837e9594 | 228 | mutex_unlock(&wf_lock); |
75722d39 BH |
229 | |
230 | return 0; | |
231 | } | |
232 | EXPORT_SYMBOL_GPL(wf_register_control); | |
233 | ||
234 | void wf_unregister_control(struct wf_control *ct) | |
235 | { | |
837e9594 | 236 | mutex_lock(&wf_lock); |
75722d39 | 237 | list_del(&ct->link); |
837e9594 | 238 | mutex_unlock(&wf_lock); |
75722d39 BH |
239 | |
240 | DBG("wf: Unregistered control %s\n", ct->name); | |
241 | ||
242 | kref_put(&ct->ref, wf_control_release); | |
243 | } | |
244 | EXPORT_SYMBOL_GPL(wf_unregister_control); | |
245 | ||
246 | struct wf_control * wf_find_control(const char *name) | |
247 | { | |
248 | struct wf_control *ct; | |
249 | ||
837e9594 | 250 | mutex_lock(&wf_lock); |
75722d39 BH |
251 | list_for_each_entry(ct, &wf_controls, link) { |
252 | if (!strcmp(ct->name, name)) { | |
253 | if (wf_get_control(ct)) | |
254 | ct = NULL; | |
837e9594 | 255 | mutex_unlock(&wf_lock); |
75722d39 BH |
256 | return ct; |
257 | } | |
258 | } | |
837e9594 | 259 | mutex_unlock(&wf_lock); |
75722d39 BH |
260 | return NULL; |
261 | } | |
262 | EXPORT_SYMBOL_GPL(wf_find_control); | |
263 | ||
264 | int wf_get_control(struct wf_control *ct) | |
265 | { | |
266 | if (!try_module_get(ct->ops->owner)) | |
267 | return -ENODEV; | |
268 | kref_get(&ct->ref); | |
269 | return 0; | |
270 | } | |
271 | EXPORT_SYMBOL_GPL(wf_get_control); | |
272 | ||
273 | void wf_put_control(struct wf_control *ct) | |
274 | { | |
275 | struct module *mod = ct->ops->owner; | |
276 | kref_put(&ct->ref, wf_control_release); | |
277 | module_put(mod); | |
278 | } | |
279 | EXPORT_SYMBOL_GPL(wf_put_control); | |
280 | ||
281 | ||
282 | /* | |
283 | * Sensors | |
284 | */ | |
285 | ||
286 | ||
287 | static void wf_sensor_release(struct kref *kref) | |
288 | { | |
289 | struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref); | |
290 | ||
291 | DBG("wf: Deleting sensor %s\n", sr->name); | |
292 | ||
293 | if (sr->ops && sr->ops->release) | |
294 | sr->ops->release(sr); | |
295 | else | |
296 | kfree(sr); | |
297 | } | |
298 | ||
ac171c46 BH |
299 | static ssize_t wf_show_sensor(struct device *dev, |
300 | struct device_attribute *attr, char *buf) | |
301 | { | |
302 | struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr); | |
303 | s32 val = 0; | |
304 | int err; | |
305 | ||
306 | err = sens->ops->get_value(sens, &val); | |
307 | if (err < 0) | |
308 | return err; | |
309 | return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val)); | |
310 | } | |
311 | ||
75722d39 BH |
312 | int wf_register_sensor(struct wf_sensor *new_sr) |
313 | { | |
314 | struct wf_sensor *sr; | |
315 | ||
837e9594 | 316 | mutex_lock(&wf_lock); |
75722d39 BH |
317 | list_for_each_entry(sr, &wf_sensors, link) { |
318 | if (!strcmp(sr->name, new_sr->name)) { | |
319 | printk(KERN_WARNING "windfarm: trying to register" | |
320 | " duplicate sensor %s\n", sr->name); | |
837e9594 | 321 | mutex_unlock(&wf_lock); |
75722d39 BH |
322 | return -EEXIST; |
323 | } | |
324 | } | |
325 | kref_init(&new_sr->ref); | |
326 | list_add(&new_sr->link, &wf_sensors); | |
327 | ||
ac171c46 | 328 | new_sr->attr.attr.name = new_sr->name; |
ac171c46 BH |
329 | new_sr->attr.attr.mode = 0444; |
330 | new_sr->attr.show = wf_show_sensor; | |
331 | new_sr->attr.store = NULL; | |
ccd308f0 SR |
332 | if (device_create_file(&wf_platform_device.dev, &new_sr->attr)) |
333 | printk(KERN_WARNING "windfarm: device_create_file failed" | |
334 | " for %s\n", new_sr->name); | |
335 | /* the subsystem still does useful work without the file */ | |
ac171c46 | 336 | |
75722d39 BH |
337 | DBG("wf: Registered sensor %s\n", new_sr->name); |
338 | ||
339 | wf_notify(WF_EVENT_NEW_SENSOR, new_sr); | |
837e9594 | 340 | mutex_unlock(&wf_lock); |
75722d39 BH |
341 | |
342 | return 0; | |
343 | } | |
344 | EXPORT_SYMBOL_GPL(wf_register_sensor); | |
345 | ||
346 | void wf_unregister_sensor(struct wf_sensor *sr) | |
347 | { | |
837e9594 | 348 | mutex_lock(&wf_lock); |
75722d39 | 349 | list_del(&sr->link); |
837e9594 | 350 | mutex_unlock(&wf_lock); |
75722d39 BH |
351 | |
352 | DBG("wf: Unregistered sensor %s\n", sr->name); | |
353 | ||
354 | wf_put_sensor(sr); | |
355 | } | |
356 | EXPORT_SYMBOL_GPL(wf_unregister_sensor); | |
357 | ||
358 | struct wf_sensor * wf_find_sensor(const char *name) | |
359 | { | |
360 | struct wf_sensor *sr; | |
361 | ||
837e9594 | 362 | mutex_lock(&wf_lock); |
75722d39 BH |
363 | list_for_each_entry(sr, &wf_sensors, link) { |
364 | if (!strcmp(sr->name, name)) { | |
365 | if (wf_get_sensor(sr)) | |
366 | sr = NULL; | |
837e9594 | 367 | mutex_unlock(&wf_lock); |
75722d39 BH |
368 | return sr; |
369 | } | |
370 | } | |
837e9594 | 371 | mutex_unlock(&wf_lock); |
75722d39 BH |
372 | return NULL; |
373 | } | |
374 | EXPORT_SYMBOL_GPL(wf_find_sensor); | |
375 | ||
376 | int wf_get_sensor(struct wf_sensor *sr) | |
377 | { | |
378 | if (!try_module_get(sr->ops->owner)) | |
379 | return -ENODEV; | |
380 | kref_get(&sr->ref); | |
381 | return 0; | |
382 | } | |
383 | EXPORT_SYMBOL_GPL(wf_get_sensor); | |
384 | ||
385 | void wf_put_sensor(struct wf_sensor *sr) | |
386 | { | |
387 | struct module *mod = sr->ops->owner; | |
388 | kref_put(&sr->ref, wf_sensor_release); | |
389 | module_put(mod); | |
390 | } | |
391 | EXPORT_SYMBOL_GPL(wf_put_sensor); | |
392 | ||
393 | ||
394 | /* | |
395 | * Client & notification | |
396 | */ | |
397 | ||
398 | int wf_register_client(struct notifier_block *nb) | |
399 | { | |
400 | int rc; | |
401 | struct wf_control *ct; | |
402 | struct wf_sensor *sr; | |
403 | ||
837e9594 | 404 | mutex_lock(&wf_lock); |
e041c683 | 405 | rc = blocking_notifier_chain_register(&wf_client_list, nb); |
75722d39 BH |
406 | if (rc != 0) |
407 | goto bail; | |
408 | wf_client_count++; | |
409 | list_for_each_entry(ct, &wf_controls, link) | |
410 | wf_notify(WF_EVENT_NEW_CONTROL, ct); | |
411 | list_for_each_entry(sr, &wf_sensors, link) | |
412 | wf_notify(WF_EVENT_NEW_SENSOR, sr); | |
413 | if (wf_client_count == 1) | |
414 | wf_start_thread(); | |
415 | bail: | |
837e9594 | 416 | mutex_unlock(&wf_lock); |
75722d39 BH |
417 | return rc; |
418 | } | |
419 | EXPORT_SYMBOL_GPL(wf_register_client); | |
420 | ||
421 | int wf_unregister_client(struct notifier_block *nb) | |
422 | { | |
837e9594 | 423 | mutex_lock(&wf_lock); |
e041c683 | 424 | blocking_notifier_chain_unregister(&wf_client_list, nb); |
75722d39 BH |
425 | wf_client_count++; |
426 | if (wf_client_count == 0) | |
427 | wf_stop_thread(); | |
837e9594 | 428 | mutex_unlock(&wf_lock); |
75722d39 BH |
429 | |
430 | return 0; | |
431 | } | |
432 | EXPORT_SYMBOL_GPL(wf_unregister_client); | |
433 | ||
434 | void wf_set_overtemp(void) | |
435 | { | |
837e9594 | 436 | mutex_lock(&wf_lock); |
75722d39 BH |
437 | wf_overtemp++; |
438 | if (wf_overtemp == 1) { | |
439 | printk(KERN_WARNING "windfarm: Overtemp condition detected !\n"); | |
440 | wf_overtemp_counter = 0; | |
441 | wf_notify(WF_EVENT_OVERTEMP, NULL); | |
442 | } | |
837e9594 | 443 | mutex_unlock(&wf_lock); |
75722d39 BH |
444 | } |
445 | EXPORT_SYMBOL_GPL(wf_set_overtemp); | |
446 | ||
447 | void wf_clear_overtemp(void) | |
448 | { | |
837e9594 | 449 | mutex_lock(&wf_lock); |
75722d39 BH |
450 | WARN_ON(wf_overtemp == 0); |
451 | if (wf_overtemp == 0) { | |
837e9594 | 452 | mutex_unlock(&wf_lock); |
75722d39 BH |
453 | return; |
454 | } | |
455 | wf_overtemp--; | |
456 | if (wf_overtemp == 0) { | |
457 | printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n"); | |
458 | wf_notify(WF_EVENT_NORMALTEMP, NULL); | |
459 | } | |
837e9594 | 460 | mutex_unlock(&wf_lock); |
75722d39 BH |
461 | } |
462 | EXPORT_SYMBOL_GPL(wf_clear_overtemp); | |
463 | ||
464 | int wf_is_overtemp(void) | |
465 | { | |
466 | return (wf_overtemp != 0); | |
467 | } | |
468 | EXPORT_SYMBOL_GPL(wf_is_overtemp); | |
469 | ||
75722d39 BH |
470 | static int __init windfarm_core_init(void) |
471 | { | |
472 | DBG("wf: core loaded\n"); | |
473 | ||
b55fafc5 BH |
474 | /* Don't register on old machines that use therm_pm72 for now */ |
475 | if (machine_is_compatible("PowerMac7,2") || | |
476 | machine_is_compatible("PowerMac7,3") || | |
477 | machine_is_compatible("RackMac3,1")) | |
478 | return -ENODEV; | |
75722d39 BH |
479 | platform_device_register(&wf_platform_device); |
480 | return 0; | |
481 | } | |
482 | ||
483 | static void __exit windfarm_core_exit(void) | |
484 | { | |
485 | BUG_ON(wf_client_count != 0); | |
486 | ||
487 | DBG("wf: core unloaded\n"); | |
488 | ||
489 | platform_device_unregister(&wf_platform_device); | |
490 | } | |
491 | ||
492 | ||
493 | module_init(windfarm_core_init); | |
494 | module_exit(windfarm_core_exit); | |
495 | ||
496 | MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); | |
497 | MODULE_DESCRIPTION("Core component of PowerMac thermal control"); | |
498 | MODULE_LICENSE("GPL"); | |
499 |