Commit | Line | Data |
---|---|---|
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> | |
5a0e3ad6 | 28 | #include <linux/slab.h> |
75722d39 BH |
29 | #include <linux/init.h> |
30 | #include <linux/spinlock.h> | |
75722d39 BH |
31 | #include <linux/kthread.h> |
32 | #include <linux/jiffies.h> | |
33 | #include <linux/reboot.h> | |
34 | #include <linux/device.h> | |
35 | #include <linux/platform_device.h> | |
837e9594 | 36 | #include <linux/mutex.h> |
7dfb7103 | 37 | #include <linux/freezer.h> |
75722d39 | 38 | |
b55fafc5 BH |
39 | #include <asm/prom.h> |
40 | ||
75722d39 BH |
41 | #include "windfarm.h" |
42 | ||
43 | #define VERSION "0.2" | |
44 | ||
45 | #undef DEBUG | |
46 | ||
47 | #ifdef DEBUG | |
48 | #define DBG(args...) printk(args) | |
49 | #else | |
50 | #define DBG(args...) do { } while(0) | |
51 | #endif | |
52 | ||
53 | static LIST_HEAD(wf_controls); | |
54 | static LIST_HEAD(wf_sensors); | |
837e9594 | 55 | static DEFINE_MUTEX(wf_lock); |
e041c683 | 56 | static BLOCKING_NOTIFIER_HEAD(wf_client_list); |
75722d39 BH |
57 | static int wf_client_count; |
58 | static unsigned int wf_overtemp; | |
59 | static unsigned int wf_overtemp_counter; | |
60 | struct task_struct *wf_thread; | |
61 | ||
ac171c46 BH |
62 | static struct platform_device wf_platform_device = { |
63 | .name = "windfarm", | |
64 | }; | |
65 | ||
75722d39 BH |
66 | /* |
67 | * Utilities & tick thread | |
68 | */ | |
69 | ||
70 | static inline void wf_notify(int event, void *param) | |
71 | { | |
e041c683 | 72 | blocking_notifier_call_chain(&wf_client_list, event, param); |
75722d39 BH |
73 | } |
74 | ||
ca94bbab | 75 | static int wf_critical_overtemp(void) |
75722d39 BH |
76 | { |
77 | static char * critical_overtemp_path = "/sbin/critical_overtemp"; | |
78 | char *argv[] = { critical_overtemp_path, NULL }; | |
79 | static char *envp[] = { "HOME=/", | |
80 | "TERM=linux", | |
81 | "PATH=/sbin:/usr/sbin:/bin:/usr/bin", | |
82 | NULL }; | |
83 | ||
86313c48 JF |
84 | return call_usermodehelper(critical_overtemp_path, |
85 | argv, envp, UMH_WAIT_EXEC); | |
75722d39 | 86 | } |
75722d39 BH |
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(); |
67b60518 JB |
97 | while (!kthread_should_stop()) { |
98 | try_to_freeze(); | |
99 | ||
75722d39 BH |
100 | if (time_after_eq(jiffies, next)) { |
101 | wf_notify(WF_EVENT_TICK, NULL); | |
102 | if (wf_overtemp) { | |
103 | wf_overtemp_counter++; | |
104 | /* 10 seconds overtemp, notify userland */ | |
105 | if (wf_overtemp_counter > 10) | |
106 | wf_critical_overtemp(); | |
107 | /* 30 seconds, shutdown */ | |
108 | if (wf_overtemp_counter > 30) { | |
109 | printk(KERN_ERR "windfarm: Overtemp " | |
110 | "for more than 30" | |
111 | " seconds, shutting down\n"); | |
112 | machine_power_off(); | |
113 | } | |
114 | } | |
115 | next += HZ; | |
116 | } | |
117 | ||
118 | delay = next - jiffies; | |
119 | if (delay <= HZ) | |
120 | schedule_timeout_interruptible(delay); | |
75722d39 BH |
121 | } |
122 | ||
123 | DBG("wf: thread stopped\n"); | |
124 | ||
125 | return 0; | |
126 | } | |
127 | ||
128 | static void wf_start_thread(void) | |
129 | { | |
130 | wf_thread = kthread_run(wf_thread_func, NULL, "kwindfarm"); | |
131 | if (IS_ERR(wf_thread)) { | |
132 | printk(KERN_ERR "windfarm: failed to create thread,err %ld\n", | |
133 | PTR_ERR(wf_thread)); | |
134 | wf_thread = NULL; | |
135 | } | |
136 | } | |
137 | ||
138 | ||
139 | static void wf_stop_thread(void) | |
140 | { | |
141 | if (wf_thread) | |
142 | kthread_stop(wf_thread); | |
143 | wf_thread = NULL; | |
144 | } | |
145 | ||
146 | /* | |
147 | * Controls | |
148 | */ | |
149 | ||
150 | static void wf_control_release(struct kref *kref) | |
151 | { | |
152 | struct wf_control *ct = container_of(kref, struct wf_control, ref); | |
153 | ||
154 | DBG("wf: Deleting control %s\n", ct->name); | |
155 | ||
156 | if (ct->ops && ct->ops->release) | |
157 | ct->ops->release(ct); | |
158 | else | |
159 | kfree(ct); | |
160 | } | |
161 | ||
ac171c46 BH |
162 | static ssize_t wf_show_control(struct device *dev, |
163 | struct device_attribute *attr, char *buf) | |
164 | { | |
165 | struct wf_control *ctrl = container_of(attr, struct wf_control, attr); | |
ea5c64b0 | 166 | const char *typestr; |
ac171c46 BH |
167 | s32 val = 0; |
168 | int err; | |
169 | ||
170 | err = ctrl->ops->get_value(ctrl, &val); | |
6cd32099 BH |
171 | if (err < 0) { |
172 | if (err == -EFAULT) | |
173 | return sprintf(buf, "<HW FAULT>\n"); | |
ac171c46 | 174 | return err; |
6cd32099 | 175 | } |
ea5c64b0 BH |
176 | switch(ctrl->type) { |
177 | case WF_CONTROL_RPM_FAN: | |
178 | typestr = " RPM"; | |
179 | break; | |
180 | case WF_CONTROL_PWM_FAN: | |
181 | typestr = " %"; | |
182 | break; | |
183 | default: | |
184 | typestr = ""; | |
185 | } | |
186 | return sprintf(buf, "%d%s\n", val, typestr); | |
ac171c46 BH |
187 | } |
188 | ||
189 | /* This is really only for debugging... */ | |
190 | static ssize_t wf_store_control(struct device *dev, | |
191 | struct device_attribute *attr, | |
192 | const char *buf, size_t count) | |
193 | { | |
194 | struct wf_control *ctrl = container_of(attr, struct wf_control, attr); | |
195 | int val; | |
196 | int err; | |
197 | char *endp; | |
198 | ||
199 | val = simple_strtoul(buf, &endp, 0); | |
200 | while (endp < buf + count && (*endp == ' ' || *endp == '\n')) | |
201 | ++endp; | |
202 | if (endp - buf < count) | |
203 | return -EINVAL; | |
204 | err = ctrl->ops->set_value(ctrl, val); | |
205 | if (err < 0) | |
206 | return err; | |
207 | return count; | |
208 | } | |
209 | ||
75722d39 BH |
210 | int wf_register_control(struct wf_control *new_ct) |
211 | { | |
212 | struct wf_control *ct; | |
213 | ||
837e9594 | 214 | mutex_lock(&wf_lock); |
75722d39 BH |
215 | list_for_each_entry(ct, &wf_controls, link) { |
216 | if (!strcmp(ct->name, new_ct->name)) { | |
217 | printk(KERN_WARNING "windfarm: trying to register" | |
218 | " duplicate control %s\n", ct->name); | |
837e9594 | 219 | mutex_unlock(&wf_lock); |
75722d39 BH |
220 | return -EEXIST; |
221 | } | |
222 | } | |
223 | kref_init(&new_ct->ref); | |
224 | list_add(&new_ct->link, &wf_controls); | |
225 | ||
12765517 | 226 | sysfs_attr_init(&new_ct->attr.attr); |
ac171c46 | 227 | new_ct->attr.attr.name = new_ct->name; |
ac171c46 BH |
228 | new_ct->attr.attr.mode = 0644; |
229 | new_ct->attr.show = wf_show_control; | |
230 | new_ct->attr.store = wf_store_control; | |
ccd308f0 SR |
231 | if (device_create_file(&wf_platform_device.dev, &new_ct->attr)) |
232 | printk(KERN_WARNING "windfarm: device_create_file failed" | |
233 | " for %s\n", new_ct->name); | |
234 | /* the subsystem still does useful work without the file */ | |
ac171c46 | 235 | |
75722d39 BH |
236 | DBG("wf: Registered control %s\n", new_ct->name); |
237 | ||
238 | wf_notify(WF_EVENT_NEW_CONTROL, new_ct); | |
837e9594 | 239 | mutex_unlock(&wf_lock); |
75722d39 BH |
240 | |
241 | return 0; | |
242 | } | |
243 | EXPORT_SYMBOL_GPL(wf_register_control); | |
244 | ||
245 | void wf_unregister_control(struct wf_control *ct) | |
246 | { | |
837e9594 | 247 | mutex_lock(&wf_lock); |
75722d39 | 248 | list_del(&ct->link); |
837e9594 | 249 | mutex_unlock(&wf_lock); |
75722d39 BH |
250 | |
251 | DBG("wf: Unregistered control %s\n", ct->name); | |
252 | ||
253 | kref_put(&ct->ref, wf_control_release); | |
254 | } | |
255 | EXPORT_SYMBOL_GPL(wf_unregister_control); | |
256 | ||
75722d39 BH |
257 | int wf_get_control(struct wf_control *ct) |
258 | { | |
259 | if (!try_module_get(ct->ops->owner)) | |
260 | return -ENODEV; | |
261 | kref_get(&ct->ref); | |
262 | return 0; | |
263 | } | |
264 | EXPORT_SYMBOL_GPL(wf_get_control); | |
265 | ||
266 | void wf_put_control(struct wf_control *ct) | |
267 | { | |
268 | struct module *mod = ct->ops->owner; | |
269 | kref_put(&ct->ref, wf_control_release); | |
270 | module_put(mod); | |
271 | } | |
272 | EXPORT_SYMBOL_GPL(wf_put_control); | |
273 | ||
274 | ||
275 | /* | |
276 | * Sensors | |
277 | */ | |
278 | ||
279 | ||
280 | static void wf_sensor_release(struct kref *kref) | |
281 | { | |
282 | struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref); | |
283 | ||
284 | DBG("wf: Deleting sensor %s\n", sr->name); | |
285 | ||
286 | if (sr->ops && sr->ops->release) | |
287 | sr->ops->release(sr); | |
288 | else | |
289 | kfree(sr); | |
290 | } | |
291 | ||
ac171c46 BH |
292 | static ssize_t wf_show_sensor(struct device *dev, |
293 | struct device_attribute *attr, char *buf) | |
294 | { | |
295 | struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr); | |
296 | s32 val = 0; | |
297 | int err; | |
298 | ||
299 | err = sens->ops->get_value(sens, &val); | |
300 | if (err < 0) | |
301 | return err; | |
302 | return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val)); | |
303 | } | |
304 | ||
75722d39 BH |
305 | int wf_register_sensor(struct wf_sensor *new_sr) |
306 | { | |
307 | struct wf_sensor *sr; | |
308 | ||
837e9594 | 309 | mutex_lock(&wf_lock); |
75722d39 BH |
310 | list_for_each_entry(sr, &wf_sensors, link) { |
311 | if (!strcmp(sr->name, new_sr->name)) { | |
312 | printk(KERN_WARNING "windfarm: trying to register" | |
313 | " duplicate sensor %s\n", sr->name); | |
837e9594 | 314 | mutex_unlock(&wf_lock); |
75722d39 BH |
315 | return -EEXIST; |
316 | } | |
317 | } | |
318 | kref_init(&new_sr->ref); | |
319 | list_add(&new_sr->link, &wf_sensors); | |
320 | ||
b35c74da | 321 | sysfs_attr_init(&new_sr->attr.attr); |
ac171c46 | 322 | new_sr->attr.attr.name = new_sr->name; |
ac171c46 BH |
323 | new_sr->attr.attr.mode = 0444; |
324 | new_sr->attr.show = wf_show_sensor; | |
325 | new_sr->attr.store = NULL; | |
ccd308f0 SR |
326 | if (device_create_file(&wf_platform_device.dev, &new_sr->attr)) |
327 | printk(KERN_WARNING "windfarm: device_create_file failed" | |
328 | " for %s\n", new_sr->name); | |
329 | /* the subsystem still does useful work without the file */ | |
ac171c46 | 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 | ||
75722d39 BH |
352 | int wf_get_sensor(struct wf_sensor *sr) |
353 | { | |
354 | if (!try_module_get(sr->ops->owner)) | |
355 | return -ENODEV; | |
356 | kref_get(&sr->ref); | |
357 | return 0; | |
358 | } | |
359 | EXPORT_SYMBOL_GPL(wf_get_sensor); | |
360 | ||
361 | void wf_put_sensor(struct wf_sensor *sr) | |
362 | { | |
363 | struct module *mod = sr->ops->owner; | |
364 | kref_put(&sr->ref, wf_sensor_release); | |
365 | module_put(mod); | |
366 | } | |
367 | EXPORT_SYMBOL_GPL(wf_put_sensor); | |
368 | ||
369 | ||
370 | /* | |
371 | * Client & notification | |
372 | */ | |
373 | ||
374 | int wf_register_client(struct notifier_block *nb) | |
375 | { | |
376 | int rc; | |
377 | struct wf_control *ct; | |
378 | struct wf_sensor *sr; | |
379 | ||
837e9594 | 380 | mutex_lock(&wf_lock); |
e041c683 | 381 | rc = blocking_notifier_chain_register(&wf_client_list, nb); |
75722d39 BH |
382 | if (rc != 0) |
383 | goto bail; | |
384 | wf_client_count++; | |
385 | list_for_each_entry(ct, &wf_controls, link) | |
386 | wf_notify(WF_EVENT_NEW_CONTROL, ct); | |
387 | list_for_each_entry(sr, &wf_sensors, link) | |
388 | wf_notify(WF_EVENT_NEW_SENSOR, sr); | |
389 | if (wf_client_count == 1) | |
390 | wf_start_thread(); | |
391 | bail: | |
837e9594 | 392 | mutex_unlock(&wf_lock); |
75722d39 BH |
393 | return rc; |
394 | } | |
395 | EXPORT_SYMBOL_GPL(wf_register_client); | |
396 | ||
397 | int wf_unregister_client(struct notifier_block *nb) | |
398 | { | |
837e9594 | 399 | mutex_lock(&wf_lock); |
e041c683 | 400 | blocking_notifier_chain_unregister(&wf_client_list, nb); |
fe2b5921 | 401 | wf_client_count--; |
75722d39 BH |
402 | if (wf_client_count == 0) |
403 | wf_stop_thread(); | |
837e9594 | 404 | mutex_unlock(&wf_lock); |
75722d39 BH |
405 | |
406 | return 0; | |
407 | } | |
408 | EXPORT_SYMBOL_GPL(wf_unregister_client); | |
409 | ||
410 | void wf_set_overtemp(void) | |
411 | { | |
837e9594 | 412 | mutex_lock(&wf_lock); |
75722d39 BH |
413 | wf_overtemp++; |
414 | if (wf_overtemp == 1) { | |
415 | printk(KERN_WARNING "windfarm: Overtemp condition detected !\n"); | |
416 | wf_overtemp_counter = 0; | |
417 | wf_notify(WF_EVENT_OVERTEMP, NULL); | |
418 | } | |
837e9594 | 419 | mutex_unlock(&wf_lock); |
75722d39 BH |
420 | } |
421 | EXPORT_SYMBOL_GPL(wf_set_overtemp); | |
422 | ||
423 | void wf_clear_overtemp(void) | |
424 | { | |
837e9594 | 425 | mutex_lock(&wf_lock); |
75722d39 BH |
426 | WARN_ON(wf_overtemp == 0); |
427 | if (wf_overtemp == 0) { | |
837e9594 | 428 | mutex_unlock(&wf_lock); |
75722d39 BH |
429 | return; |
430 | } | |
431 | wf_overtemp--; | |
432 | if (wf_overtemp == 0) { | |
433 | printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n"); | |
434 | wf_notify(WF_EVENT_NORMALTEMP, NULL); | |
435 | } | |
837e9594 | 436 | mutex_unlock(&wf_lock); |
75722d39 BH |
437 | } |
438 | EXPORT_SYMBOL_GPL(wf_clear_overtemp); | |
439 | ||
75722d39 BH |
440 | static int __init windfarm_core_init(void) |
441 | { | |
442 | DBG("wf: core loaded\n"); | |
443 | ||
444 | platform_device_register(&wf_platform_device); | |
445 | return 0; | |
446 | } | |
447 | ||
448 | static void __exit windfarm_core_exit(void) | |
449 | { | |
450 | BUG_ON(wf_client_count != 0); | |
451 | ||
452 | DBG("wf: core unloaded\n"); | |
453 | ||
454 | platform_device_unregister(&wf_platform_device); | |
455 | } | |
456 | ||
457 | ||
458 | module_init(windfarm_core_init); | |
459 | module_exit(windfarm_core_exit); | |
460 | ||
461 | MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); | |
462 | MODULE_DESCRIPTION("Core component of PowerMac thermal control"); | |
463 | MODULE_LICENSE("GPL"); | |
464 |