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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 | ||
83 | return call_usermodehelper(critical_overtemp_path, argv, envp, 0); | |
84 | } | |
85 | EXPORT_SYMBOL_GPL(wf_critical_overtemp); | |
86 | ||
87 | static int wf_thread_func(void *data) | |
88 | { | |
89 | unsigned long next, delay; | |
90 | ||
91 | next = jiffies; | |
92 | ||
93 | DBG("wf: thread started\n"); | |
94 | ||
95 | while(!kthread_should_stop()) { | |
75722d39 BH |
96 | if (time_after_eq(jiffies, next)) { |
97 | wf_notify(WF_EVENT_TICK, NULL); | |
98 | if (wf_overtemp) { | |
99 | wf_overtemp_counter++; | |
100 | /* 10 seconds overtemp, notify userland */ | |
101 | if (wf_overtemp_counter > 10) | |
102 | wf_critical_overtemp(); | |
103 | /* 30 seconds, shutdown */ | |
104 | if (wf_overtemp_counter > 30) { | |
105 | printk(KERN_ERR "windfarm: Overtemp " | |
106 | "for more than 30" | |
107 | " seconds, shutting down\n"); | |
108 | machine_power_off(); | |
109 | } | |
110 | } | |
111 | next += HZ; | |
112 | } | |
113 | ||
114 | delay = next - jiffies; | |
115 | if (delay <= HZ) | |
116 | schedule_timeout_interruptible(delay); | |
117 | ||
1ed2ddf3 JB |
118 | /* there should be no non-suspend signal, but oh well */ |
119 | if (signal_pending(current) && !try_to_freeze()) { | |
75722d39 BH |
120 | printk(KERN_WARNING "windfarm: thread got sigl !\n"); |
121 | break; | |
122 | } | |
123 | } | |
124 | ||
125 | DBG("wf: thread stopped\n"); | |
126 | ||
127 | return 0; | |
128 | } | |
129 | ||
130 | static void wf_start_thread(void) | |
131 | { | |
132 | wf_thread = kthread_run(wf_thread_func, NULL, "kwindfarm"); | |
133 | if (IS_ERR(wf_thread)) { | |
134 | printk(KERN_ERR "windfarm: failed to create thread,err %ld\n", | |
135 | PTR_ERR(wf_thread)); | |
136 | wf_thread = NULL; | |
137 | } | |
138 | } | |
139 | ||
140 | ||
141 | static void wf_stop_thread(void) | |
142 | { | |
143 | if (wf_thread) | |
144 | kthread_stop(wf_thread); | |
145 | wf_thread = NULL; | |
146 | } | |
147 | ||
148 | /* | |
149 | * Controls | |
150 | */ | |
151 | ||
152 | static void wf_control_release(struct kref *kref) | |
153 | { | |
154 | struct wf_control *ct = container_of(kref, struct wf_control, ref); | |
155 | ||
156 | DBG("wf: Deleting control %s\n", ct->name); | |
157 | ||
158 | if (ct->ops && ct->ops->release) | |
159 | ct->ops->release(ct); | |
160 | else | |
161 | kfree(ct); | |
162 | } | |
163 | ||
ac171c46 BH |
164 | static ssize_t wf_show_control(struct device *dev, |
165 | struct device_attribute *attr, char *buf) | |
166 | { | |
167 | struct wf_control *ctrl = container_of(attr, struct wf_control, attr); | |
168 | s32 val = 0; | |
169 | int err; | |
170 | ||
171 | err = ctrl->ops->get_value(ctrl, &val); | |
172 | if (err < 0) | |
173 | return err; | |
174 | return sprintf(buf, "%d\n", val); | |
175 | } | |
176 | ||
177 | /* This is really only for debugging... */ | |
178 | static ssize_t wf_store_control(struct device *dev, | |
179 | struct device_attribute *attr, | |
180 | const char *buf, size_t count) | |
181 | { | |
182 | struct wf_control *ctrl = container_of(attr, struct wf_control, attr); | |
183 | int val; | |
184 | int err; | |
185 | char *endp; | |
186 | ||
187 | val = simple_strtoul(buf, &endp, 0); | |
188 | while (endp < buf + count && (*endp == ' ' || *endp == '\n')) | |
189 | ++endp; | |
190 | if (endp - buf < count) | |
191 | return -EINVAL; | |
192 | err = ctrl->ops->set_value(ctrl, val); | |
193 | if (err < 0) | |
194 | return err; | |
195 | return count; | |
196 | } | |
197 | ||
75722d39 BH |
198 | int wf_register_control(struct wf_control *new_ct) |
199 | { | |
200 | struct wf_control *ct; | |
201 | ||
837e9594 | 202 | mutex_lock(&wf_lock); |
75722d39 BH |
203 | list_for_each_entry(ct, &wf_controls, link) { |
204 | if (!strcmp(ct->name, new_ct->name)) { | |
205 | printk(KERN_WARNING "windfarm: trying to register" | |
206 | " duplicate control %s\n", ct->name); | |
837e9594 | 207 | mutex_unlock(&wf_lock); |
75722d39 BH |
208 | return -EEXIST; |
209 | } | |
210 | } | |
211 | kref_init(&new_ct->ref); | |
212 | list_add(&new_ct->link, &wf_controls); | |
213 | ||
ac171c46 BH |
214 | new_ct->attr.attr.name = new_ct->name; |
215 | new_ct->attr.attr.owner = THIS_MODULE; | |
216 | new_ct->attr.attr.mode = 0644; | |
217 | new_ct->attr.show = wf_show_control; | |
218 | new_ct->attr.store = wf_store_control; | |
219 | device_create_file(&wf_platform_device.dev, &new_ct->attr); | |
220 | ||
75722d39 BH |
221 | DBG("wf: Registered control %s\n", new_ct->name); |
222 | ||
223 | wf_notify(WF_EVENT_NEW_CONTROL, new_ct); | |
837e9594 | 224 | mutex_unlock(&wf_lock); |
75722d39 BH |
225 | |
226 | return 0; | |
227 | } | |
228 | EXPORT_SYMBOL_GPL(wf_register_control); | |
229 | ||
230 | void wf_unregister_control(struct wf_control *ct) | |
231 | { | |
837e9594 | 232 | mutex_lock(&wf_lock); |
75722d39 | 233 | list_del(&ct->link); |
837e9594 | 234 | mutex_unlock(&wf_lock); |
75722d39 BH |
235 | |
236 | DBG("wf: Unregistered control %s\n", ct->name); | |
237 | ||
238 | kref_put(&ct->ref, wf_control_release); | |
239 | } | |
240 | EXPORT_SYMBOL_GPL(wf_unregister_control); | |
241 | ||
242 | struct wf_control * wf_find_control(const char *name) | |
243 | { | |
244 | struct wf_control *ct; | |
245 | ||
837e9594 | 246 | mutex_lock(&wf_lock); |
75722d39 BH |
247 | list_for_each_entry(ct, &wf_controls, link) { |
248 | if (!strcmp(ct->name, name)) { | |
249 | if (wf_get_control(ct)) | |
250 | ct = NULL; | |
837e9594 | 251 | mutex_unlock(&wf_lock); |
75722d39 BH |
252 | return ct; |
253 | } | |
254 | } | |
837e9594 | 255 | mutex_unlock(&wf_lock); |
75722d39 BH |
256 | return NULL; |
257 | } | |
258 | EXPORT_SYMBOL_GPL(wf_find_control); | |
259 | ||
260 | int wf_get_control(struct wf_control *ct) | |
261 | { | |
262 | if (!try_module_get(ct->ops->owner)) | |
263 | return -ENODEV; | |
264 | kref_get(&ct->ref); | |
265 | return 0; | |
266 | } | |
267 | EXPORT_SYMBOL_GPL(wf_get_control); | |
268 | ||
269 | void wf_put_control(struct wf_control *ct) | |
270 | { | |
271 | struct module *mod = ct->ops->owner; | |
272 | kref_put(&ct->ref, wf_control_release); | |
273 | module_put(mod); | |
274 | } | |
275 | EXPORT_SYMBOL_GPL(wf_put_control); | |
276 | ||
277 | ||
278 | /* | |
279 | * Sensors | |
280 | */ | |
281 | ||
282 | ||
283 | static void wf_sensor_release(struct kref *kref) | |
284 | { | |
285 | struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref); | |
286 | ||
287 | DBG("wf: Deleting sensor %s\n", sr->name); | |
288 | ||
289 | if (sr->ops && sr->ops->release) | |
290 | sr->ops->release(sr); | |
291 | else | |
292 | kfree(sr); | |
293 | } | |
294 | ||
ac171c46 BH |
295 | static ssize_t wf_show_sensor(struct device *dev, |
296 | struct device_attribute *attr, char *buf) | |
297 | { | |
298 | struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr); | |
299 | s32 val = 0; | |
300 | int err; | |
301 | ||
302 | err = sens->ops->get_value(sens, &val); | |
303 | if (err < 0) | |
304 | return err; | |
305 | return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val)); | |
306 | } | |
307 | ||
75722d39 BH |
308 | int wf_register_sensor(struct wf_sensor *new_sr) |
309 | { | |
310 | struct wf_sensor *sr; | |
311 | ||
837e9594 | 312 | mutex_lock(&wf_lock); |
75722d39 BH |
313 | list_for_each_entry(sr, &wf_sensors, link) { |
314 | if (!strcmp(sr->name, new_sr->name)) { | |
315 | printk(KERN_WARNING "windfarm: trying to register" | |
316 | " duplicate sensor %s\n", sr->name); | |
837e9594 | 317 | mutex_unlock(&wf_lock); |
75722d39 BH |
318 | return -EEXIST; |
319 | } | |
320 | } | |
321 | kref_init(&new_sr->ref); | |
322 | list_add(&new_sr->link, &wf_sensors); | |
323 | ||
ac171c46 BH |
324 | new_sr->attr.attr.name = new_sr->name; |
325 | new_sr->attr.attr.owner = THIS_MODULE; | |
326 | new_sr->attr.attr.mode = 0444; | |
327 | new_sr->attr.show = wf_show_sensor; | |
328 | new_sr->attr.store = NULL; | |
329 | device_create_file(&wf_platform_device.dev, &new_sr->attr); | |
330 | ||
75722d39 BH |
331 | DBG("wf: Registered sensor %s\n", new_sr->name); |
332 | ||
333 | wf_notify(WF_EVENT_NEW_SENSOR, new_sr); | |
837e9594 | 334 | mutex_unlock(&wf_lock); |
75722d39 BH |
335 | |
336 | return 0; | |
337 | } | |
338 | EXPORT_SYMBOL_GPL(wf_register_sensor); | |
339 | ||
340 | void wf_unregister_sensor(struct wf_sensor *sr) | |
341 | { | |
837e9594 | 342 | mutex_lock(&wf_lock); |
75722d39 | 343 | list_del(&sr->link); |
837e9594 | 344 | mutex_unlock(&wf_lock); |
75722d39 BH |
345 | |
346 | DBG("wf: Unregistered sensor %s\n", sr->name); | |
347 | ||
348 | wf_put_sensor(sr); | |
349 | } | |
350 | EXPORT_SYMBOL_GPL(wf_unregister_sensor); | |
351 | ||
352 | struct wf_sensor * wf_find_sensor(const char *name) | |
353 | { | |
354 | struct wf_sensor *sr; | |
355 | ||
837e9594 | 356 | mutex_lock(&wf_lock); |
75722d39 BH |
357 | list_for_each_entry(sr, &wf_sensors, link) { |
358 | if (!strcmp(sr->name, name)) { | |
359 | if (wf_get_sensor(sr)) | |
360 | sr = NULL; | |
837e9594 | 361 | mutex_unlock(&wf_lock); |
75722d39 BH |
362 | return sr; |
363 | } | |
364 | } | |
837e9594 | 365 | mutex_unlock(&wf_lock); |
75722d39 BH |
366 | return NULL; |
367 | } | |
368 | EXPORT_SYMBOL_GPL(wf_find_sensor); | |
369 | ||
370 | int wf_get_sensor(struct wf_sensor *sr) | |
371 | { | |
372 | if (!try_module_get(sr->ops->owner)) | |
373 | return -ENODEV; | |
374 | kref_get(&sr->ref); | |
375 | return 0; | |
376 | } | |
377 | EXPORT_SYMBOL_GPL(wf_get_sensor); | |
378 | ||
379 | void wf_put_sensor(struct wf_sensor *sr) | |
380 | { | |
381 | struct module *mod = sr->ops->owner; | |
382 | kref_put(&sr->ref, wf_sensor_release); | |
383 | module_put(mod); | |
384 | } | |
385 | EXPORT_SYMBOL_GPL(wf_put_sensor); | |
386 | ||
387 | ||
388 | /* | |
389 | * Client & notification | |
390 | */ | |
391 | ||
392 | int wf_register_client(struct notifier_block *nb) | |
393 | { | |
394 | int rc; | |
395 | struct wf_control *ct; | |
396 | struct wf_sensor *sr; | |
397 | ||
837e9594 | 398 | mutex_lock(&wf_lock); |
e041c683 | 399 | rc = blocking_notifier_chain_register(&wf_client_list, nb); |
75722d39 BH |
400 | if (rc != 0) |
401 | goto bail; | |
402 | wf_client_count++; | |
403 | list_for_each_entry(ct, &wf_controls, link) | |
404 | wf_notify(WF_EVENT_NEW_CONTROL, ct); | |
405 | list_for_each_entry(sr, &wf_sensors, link) | |
406 | wf_notify(WF_EVENT_NEW_SENSOR, sr); | |
407 | if (wf_client_count == 1) | |
408 | wf_start_thread(); | |
409 | bail: | |
837e9594 | 410 | mutex_unlock(&wf_lock); |
75722d39 BH |
411 | return rc; |
412 | } | |
413 | EXPORT_SYMBOL_GPL(wf_register_client); | |
414 | ||
415 | int wf_unregister_client(struct notifier_block *nb) | |
416 | { | |
837e9594 | 417 | mutex_lock(&wf_lock); |
e041c683 | 418 | blocking_notifier_chain_unregister(&wf_client_list, nb); |
75722d39 BH |
419 | wf_client_count++; |
420 | if (wf_client_count == 0) | |
421 | wf_stop_thread(); | |
837e9594 | 422 | mutex_unlock(&wf_lock); |
75722d39 BH |
423 | |
424 | return 0; | |
425 | } | |
426 | EXPORT_SYMBOL_GPL(wf_unregister_client); | |
427 | ||
428 | void wf_set_overtemp(void) | |
429 | { | |
837e9594 | 430 | mutex_lock(&wf_lock); |
75722d39 BH |
431 | wf_overtemp++; |
432 | if (wf_overtemp == 1) { | |
433 | printk(KERN_WARNING "windfarm: Overtemp condition detected !\n"); | |
434 | wf_overtemp_counter = 0; | |
435 | wf_notify(WF_EVENT_OVERTEMP, NULL); | |
436 | } | |
837e9594 | 437 | mutex_unlock(&wf_lock); |
75722d39 BH |
438 | } |
439 | EXPORT_SYMBOL_GPL(wf_set_overtemp); | |
440 | ||
441 | void wf_clear_overtemp(void) | |
442 | { | |
837e9594 | 443 | mutex_lock(&wf_lock); |
75722d39 BH |
444 | WARN_ON(wf_overtemp == 0); |
445 | if (wf_overtemp == 0) { | |
837e9594 | 446 | mutex_unlock(&wf_lock); |
75722d39 BH |
447 | return; |
448 | } | |
449 | wf_overtemp--; | |
450 | if (wf_overtemp == 0) { | |
451 | printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n"); | |
452 | wf_notify(WF_EVENT_NORMALTEMP, NULL); | |
453 | } | |
837e9594 | 454 | mutex_unlock(&wf_lock); |
75722d39 BH |
455 | } |
456 | EXPORT_SYMBOL_GPL(wf_clear_overtemp); | |
457 | ||
458 | int wf_is_overtemp(void) | |
459 | { | |
460 | return (wf_overtemp != 0); | |
461 | } | |
462 | EXPORT_SYMBOL_GPL(wf_is_overtemp); | |
463 | ||
75722d39 BH |
464 | static int __init windfarm_core_init(void) |
465 | { | |
466 | DBG("wf: core loaded\n"); | |
467 | ||
b55fafc5 BH |
468 | /* Don't register on old machines that use therm_pm72 for now */ |
469 | if (machine_is_compatible("PowerMac7,2") || | |
470 | machine_is_compatible("PowerMac7,3") || | |
471 | machine_is_compatible("RackMac3,1")) | |
472 | return -ENODEV; | |
75722d39 BH |
473 | platform_device_register(&wf_platform_device); |
474 | return 0; | |
475 | } | |
476 | ||
477 | static void __exit windfarm_core_exit(void) | |
478 | { | |
479 | BUG_ON(wf_client_count != 0); | |
480 | ||
481 | DBG("wf: core unloaded\n"); | |
482 | ||
483 | platform_device_unregister(&wf_platform_device); | |
484 | } | |
485 | ||
486 | ||
487 | module_init(windfarm_core_init); | |
488 | module_exit(windfarm_core_exit); | |
489 | ||
490 | MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); | |
491 | MODULE_DESCRIPTION("Core component of PowerMac thermal control"); | |
492 | MODULE_LICENSE("GPL"); | |
493 |