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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>
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>
35#include <linux/mutex.h>
36#include <linux/freezer.h>
37
38#include <asm/prom.h>
39
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
52static LIST_HEAD(wf_controls);
53static LIST_HEAD(wf_sensors);
54static DEFINE_MUTEX(wf_lock);
55static BLOCKING_NOTIFIER_HEAD(wf_client_list);
56static int wf_client_count;
57static unsigned int wf_overtemp;
58static unsigned int wf_overtemp_counter;
59struct task_struct *wf_thread;
60
61static struct platform_device wf_platform_device = {
62 .name = "windfarm",
63};
64
65
66
67
68
69static inline void wf_notify(int event, void *param)
70{
71 blocking_notifier_call_chain(&wf_client_list, event, param);
72}
73
74int 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,
84 argv, envp, UMH_WAIT_EXEC);
85}
86EXPORT_SYMBOL_GPL(wf_critical_overtemp);
87
88static int wf_thread_func(void *data)
89{
90 unsigned long next, delay;
91
92 next = jiffies;
93
94 DBG("wf: thread started\n");
95
96 set_freezable();
97 while (!kthread_should_stop()) {
98 try_to_freeze();
99
100 if (time_after_eq(jiffies, next)) {
101 wf_notify(WF_EVENT_TICK, NULL);
102 if (wf_overtemp) {
103 wf_overtemp_counter++;
104
105 if (wf_overtemp_counter > 10)
106 wf_critical_overtemp();
107
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);
121 }
122
123 DBG("wf: thread stopped\n");
124
125 return 0;
126}
127
128static 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
139static void wf_stop_thread(void)
140{
141 if (wf_thread)
142 kthread_stop(wf_thread);
143 wf_thread = NULL;
144}
145
146
147
148
149
150static 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
162static 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);
166 s32 val = 0;
167 int err;
168
169 err = ctrl->ops->get_value(ctrl, &val);
170 if (err < 0)
171 return err;
172 return sprintf(buf, "%d\n", val);
173}
174
175
176static ssize_t wf_store_control(struct device *dev,
177 struct device_attribute *attr,
178 const char *buf, size_t count)
179{
180 struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
181 int val;
182 int err;
183 char *endp;
184
185 val = simple_strtoul(buf, &endp, 0);
186 while (endp < buf + count && (*endp == ' ' || *endp == '\n'))
187 ++endp;
188 if (endp - buf < count)
189 return -EINVAL;
190 err = ctrl->ops->set_value(ctrl, val);
191 if (err < 0)
192 return err;
193 return count;
194}
195
196int wf_register_control(struct wf_control *new_ct)
197{
198 struct wf_control *ct;
199
200 mutex_lock(&wf_lock);
201 list_for_each_entry(ct, &wf_controls, link) {
202 if (!strcmp(ct->name, new_ct->name)) {
203 printk(KERN_WARNING "windfarm: trying to register"
204 " duplicate control %s\n", ct->name);
205 mutex_unlock(&wf_lock);
206 return -EEXIST;
207 }
208 }
209 kref_init(&new_ct->ref);
210 list_add(&new_ct->link, &wf_controls);
211
212 new_ct->attr.attr.name = new_ct->name;
213 new_ct->attr.attr.mode = 0644;
214 new_ct->attr.show = wf_show_control;
215 new_ct->attr.store = wf_store_control;
216 if (device_create_file(&wf_platform_device.dev, &new_ct->attr))
217 printk(KERN_WARNING "windfarm: device_create_file failed"
218 " for %s\n", new_ct->name);
219
220
221 DBG("wf: Registered control %s\n", new_ct->name);
222
223 wf_notify(WF_EVENT_NEW_CONTROL, new_ct);
224 mutex_unlock(&wf_lock);
225
226 return 0;
227}
228EXPORT_SYMBOL_GPL(wf_register_control);
229
230void wf_unregister_control(struct wf_control *ct)
231{
232 mutex_lock(&wf_lock);
233 list_del(&ct->link);
234 mutex_unlock(&wf_lock);
235
236 DBG("wf: Unregistered control %s\n", ct->name);
237
238 kref_put(&ct->ref, wf_control_release);
239}
240EXPORT_SYMBOL_GPL(wf_unregister_control);
241
242struct wf_control * wf_find_control(const char *name)
243{
244 struct wf_control *ct;
245
246 mutex_lock(&wf_lock);
247 list_for_each_entry(ct, &wf_controls, link) {
248 if (!strcmp(ct->name, name)) {
249 if (wf_get_control(ct))
250 ct = NULL;
251 mutex_unlock(&wf_lock);
252 return ct;
253 }
254 }
255 mutex_unlock(&wf_lock);
256 return NULL;
257}
258EXPORT_SYMBOL_GPL(wf_find_control);
259
260int 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}
267EXPORT_SYMBOL_GPL(wf_get_control);
268
269void 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}
275EXPORT_SYMBOL_GPL(wf_put_control);
276
277
278
279
280
281
282
283static 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
295static 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
308int wf_register_sensor(struct wf_sensor *new_sr)
309{
310 struct wf_sensor *sr;
311
312 mutex_lock(&wf_lock);
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);
317 mutex_unlock(&wf_lock);
318 return -EEXIST;
319 }
320 }
321 kref_init(&new_sr->ref);
322 list_add(&new_sr->link, &wf_sensors);
323
324 new_sr->attr.attr.name = new_sr->name;
325 new_sr->attr.attr.mode = 0444;
326 new_sr->attr.show = wf_show_sensor;
327 new_sr->attr.store = NULL;
328 if (device_create_file(&wf_platform_device.dev, &new_sr->attr))
329 printk(KERN_WARNING "windfarm: device_create_file failed"
330 " for %s\n", new_sr->name);
331
332
333 DBG("wf: Registered sensor %s\n", new_sr->name);
334
335 wf_notify(WF_EVENT_NEW_SENSOR, new_sr);
336 mutex_unlock(&wf_lock);
337
338 return 0;
339}
340EXPORT_SYMBOL_GPL(wf_register_sensor);
341
342void wf_unregister_sensor(struct wf_sensor *sr)
343{
344 mutex_lock(&wf_lock);
345 list_del(&sr->link);
346 mutex_unlock(&wf_lock);
347
348 DBG("wf: Unregistered sensor %s\n", sr->name);
349
350 wf_put_sensor(sr);
351}
352EXPORT_SYMBOL_GPL(wf_unregister_sensor);
353
354struct wf_sensor * wf_find_sensor(const char *name)
355{
356 struct wf_sensor *sr;
357
358 mutex_lock(&wf_lock);
359 list_for_each_entry(sr, &wf_sensors, link) {
360 if (!strcmp(sr->name, name)) {
361 if (wf_get_sensor(sr))
362 sr = NULL;
363 mutex_unlock(&wf_lock);
364 return sr;
365 }
366 }
367 mutex_unlock(&wf_lock);
368 return NULL;
369}
370EXPORT_SYMBOL_GPL(wf_find_sensor);
371
372int wf_get_sensor(struct wf_sensor *sr)
373{
374 if (!try_module_get(sr->ops->owner))
375 return -ENODEV;
376 kref_get(&sr->ref);
377 return 0;
378}
379EXPORT_SYMBOL_GPL(wf_get_sensor);
380
381void wf_put_sensor(struct wf_sensor *sr)
382{
383 struct module *mod = sr->ops->owner;
384 kref_put(&sr->ref, wf_sensor_release);
385 module_put(mod);
386}
387EXPORT_SYMBOL_GPL(wf_put_sensor);
388
389
390
391
392
393
394int wf_register_client(struct notifier_block *nb)
395{
396 int rc;
397 struct wf_control *ct;
398 struct wf_sensor *sr;
399
400 mutex_lock(&wf_lock);
401 rc = blocking_notifier_chain_register(&wf_client_list, nb);
402 if (rc != 0)
403 goto bail;
404 wf_client_count++;
405 list_for_each_entry(ct, &wf_controls, link)
406 wf_notify(WF_EVENT_NEW_CONTROL, ct);
407 list_for_each_entry(sr, &wf_sensors, link)
408 wf_notify(WF_EVENT_NEW_SENSOR, sr);
409 if (wf_client_count == 1)
410 wf_start_thread();
411 bail:
412 mutex_unlock(&wf_lock);
413 return rc;
414}
415EXPORT_SYMBOL_GPL(wf_register_client);
416
417int wf_unregister_client(struct notifier_block *nb)
418{
419 mutex_lock(&wf_lock);
420 blocking_notifier_chain_unregister(&wf_client_list, nb);
421 wf_client_count++;
422 if (wf_client_count == 0)
423 wf_stop_thread();
424 mutex_unlock(&wf_lock);
425
426 return 0;
427}
428EXPORT_SYMBOL_GPL(wf_unregister_client);
429
430void wf_set_overtemp(void)
431{
432 mutex_lock(&wf_lock);
433 wf_overtemp++;
434 if (wf_overtemp == 1) {
435 printk(KERN_WARNING "windfarm: Overtemp condition detected !\n");
436 wf_overtemp_counter = 0;
437 wf_notify(WF_EVENT_OVERTEMP, NULL);
438 }
439 mutex_unlock(&wf_lock);
440}
441EXPORT_SYMBOL_GPL(wf_set_overtemp);
442
443void wf_clear_overtemp(void)
444{
445 mutex_lock(&wf_lock);
446 WARN_ON(wf_overtemp == 0);
447 if (wf_overtemp == 0) {
448 mutex_unlock(&wf_lock);
449 return;
450 }
451 wf_overtemp--;
452 if (wf_overtemp == 0) {
453 printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n");
454 wf_notify(WF_EVENT_NORMALTEMP, NULL);
455 }
456 mutex_unlock(&wf_lock);
457}
458EXPORT_SYMBOL_GPL(wf_clear_overtemp);
459
460int wf_is_overtemp(void)
461{
462 return (wf_overtemp != 0);
463}
464EXPORT_SYMBOL_GPL(wf_is_overtemp);
465
466static int __init windfarm_core_init(void)
467{
468 DBG("wf: core loaded\n");
469
470
471 if (machine_is_compatible("PowerMac7,2") ||
472 machine_is_compatible("PowerMac7,3") ||
473 machine_is_compatible("RackMac3,1"))
474 return -ENODEV;
475 platform_device_register(&wf_platform_device);
476 return 0;
477}
478
479static void __exit windfarm_core_exit(void)
480{
481 BUG_ON(wf_client_count != 0);
482
483 DBG("wf: core unloaded\n");
484
485 platform_device_unregister(&wf_platform_device);
486}
487
488
489module_init(windfarm_core_init);
490module_exit(windfarm_core_exit);
491
492MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
493MODULE_DESCRIPTION("Core component of PowerMac thermal control");
494MODULE_LICENSE("GPL");
495
496
