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25#include <linux/types.h>
26#include <linux/errno.h>
27#include <linux/kernel.h>
28#include <linux/slab.h>
29#include <linux/init.h>
30#include <linux/spinlock.h>
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>
36#include <linux/mutex.h>
37#include <linux/freezer.h>
38
39#include <asm/prom.h>
40
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
53static LIST_HEAD(wf_controls);
54static LIST_HEAD(wf_sensors);
55static DEFINE_MUTEX(wf_lock);
56static BLOCKING_NOTIFIER_HEAD(wf_client_list);
57static int wf_client_count;
58static unsigned int wf_overtemp;
59static unsigned int wf_overtemp_counter;
60struct task_struct *wf_thread;
61
62static struct platform_device wf_platform_device = {
63 .name = "windfarm",
64};
65
66
67
68
69
70static inline void wf_notify(int event, void *param)
71{
72 blocking_notifier_call_chain(&wf_client_list, event, param);
73}
74
75int wf_critical_overtemp(void)
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
84 return call_usermodehelper(critical_overtemp_path,
85 argv, envp, UMH_WAIT_EXEC);
86}
87EXPORT_SYMBOL_GPL(wf_critical_overtemp);
88
89static int wf_thread_func(void *data)
90{
91 unsigned long next, delay;
92
93 next = jiffies;
94
95 DBG("wf: thread started\n");
96
97 set_freezable();
98 while (!kthread_should_stop()) {
99 try_to_freeze();
100
101 if (time_after_eq(jiffies, next)) {
102 wf_notify(WF_EVENT_TICK, NULL);
103 if (wf_overtemp) {
104 wf_overtemp_counter++;
105
106 if (wf_overtemp_counter > 10)
107 wf_critical_overtemp();
108
109 if (wf_overtemp_counter > 30) {
110 printk(KERN_ERR "windfarm: Overtemp "
111 "for more than 30"
112 " seconds, shutting down\n");
113 machine_power_off();
114 }
115 }
116 next += HZ;
117 }
118
119 delay = next - jiffies;
120 if (delay <= HZ)
121 schedule_timeout_interruptible(delay);
122 }
123
124 DBG("wf: thread stopped\n");
125
126 return 0;
127}
128
129static void wf_start_thread(void)
130{
131 wf_thread = kthread_run(wf_thread_func, NULL, "kwindfarm");
132 if (IS_ERR(wf_thread)) {
133 printk(KERN_ERR "windfarm: failed to create thread,err %ld\n",
134 PTR_ERR(wf_thread));
135 wf_thread = NULL;
136 }
137}
138
139
140static void wf_stop_thread(void)
141{
142 if (wf_thread)
143 kthread_stop(wf_thread);
144 wf_thread = NULL;
145}
146
147
148
149
150
151static void wf_control_release(struct kref *kref)
152{
153 struct wf_control *ct = container_of(kref, struct wf_control, ref);
154
155 DBG("wf: Deleting control %s\n", ct->name);
156
157 if (ct->ops && ct->ops->release)
158 ct->ops->release(ct);
159 else
160 kfree(ct);
161}
162
163static ssize_t wf_show_control(struct device *dev,
164 struct device_attribute *attr, char *buf)
165{
166 struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
167 s32 val = 0;
168 int err;
169
170 err = ctrl->ops->get_value(ctrl, &val);
171 if (err < 0)
172 return err;
173 return sprintf(buf, "%d\n", val);
174}
175
176
177static ssize_t wf_store_control(struct device *dev,
178 struct device_attribute *attr,
179 const char *buf, size_t count)
180{
181 struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
182 int val;
183 int err;
184 char *endp;
185
186 val = simple_strtoul(buf, &endp, 0);
187 while (endp < buf + count && (*endp == ' ' || *endp == '\n'))
188 ++endp;
189 if (endp - buf < count)
190 return -EINVAL;
191 err = ctrl->ops->set_value(ctrl, val);
192 if (err < 0)
193 return err;
194 return count;
195}
196
197int wf_register_control(struct wf_control *new_ct)
198{
199 struct wf_control *ct;
200
201 mutex_lock(&wf_lock);
202 list_for_each_entry(ct, &wf_controls, link) {
203 if (!strcmp(ct->name, new_ct->name)) {
204 printk(KERN_WARNING "windfarm: trying to register"
205 " duplicate control %s\n", ct->name);
206 mutex_unlock(&wf_lock);
207 return -EEXIST;
208 }
209 }
210 kref_init(&new_ct->ref);
211 list_add(&new_ct->link, &wf_controls);
212
213 sysfs_attr_init(&new_ct->attr.attr);
214 new_ct->attr.attr.name = new_ct->name;
215 new_ct->attr.attr.mode = 0644;
216 new_ct->attr.show = wf_show_control;
217 new_ct->attr.store = wf_store_control;
218 if (device_create_file(&wf_platform_device.dev, &new_ct->attr))
219 printk(KERN_WARNING "windfarm: device_create_file failed"
220 " for %s\n", new_ct->name);
221
222
223 DBG("wf: Registered control %s\n", new_ct->name);
224
225 wf_notify(WF_EVENT_NEW_CONTROL, new_ct);
226 mutex_unlock(&wf_lock);
227
228 return 0;
229}
230EXPORT_SYMBOL_GPL(wf_register_control);
231
232void wf_unregister_control(struct wf_control *ct)
233{
234 mutex_lock(&wf_lock);
235 list_del(&ct->link);
236 mutex_unlock(&wf_lock);
237
238 DBG("wf: Unregistered control %s\n", ct->name);
239
240 kref_put(&ct->ref, wf_control_release);
241}
242EXPORT_SYMBOL_GPL(wf_unregister_control);
243
244struct wf_control * wf_find_control(const char *name)
245{
246 struct wf_control *ct;
247
248 mutex_lock(&wf_lock);
249 list_for_each_entry(ct, &wf_controls, link) {
250 if (!strcmp(ct->name, name)) {
251 if (wf_get_control(ct))
252 ct = NULL;
253 mutex_unlock(&wf_lock);
254 return ct;
255 }
256 }
257 mutex_unlock(&wf_lock);
258 return NULL;
259}
260EXPORT_SYMBOL_GPL(wf_find_control);
261
262int wf_get_control(struct wf_control *ct)
263{
264 if (!try_module_get(ct->ops->owner))
265 return -ENODEV;
266 kref_get(&ct->ref);
267 return 0;
268}
269EXPORT_SYMBOL_GPL(wf_get_control);
270
271void wf_put_control(struct wf_control *ct)
272{
273 struct module *mod = ct->ops->owner;
274 kref_put(&ct->ref, wf_control_release);
275 module_put(mod);
276}
277EXPORT_SYMBOL_GPL(wf_put_control);
278
279
280
281
282
283
284
285static void wf_sensor_release(struct kref *kref)
286{
287 struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref);
288
289 DBG("wf: Deleting sensor %s\n", sr->name);
290
291 if (sr->ops && sr->ops->release)
292 sr->ops->release(sr);
293 else
294 kfree(sr);
295}
296
297static ssize_t wf_show_sensor(struct device *dev,
298 struct device_attribute *attr, char *buf)
299{
300 struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr);
301 s32 val = 0;
302 int err;
303
304 err = sens->ops->get_value(sens, &val);
305 if (err < 0)
306 return err;
307 return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val));
308}
309
310int wf_register_sensor(struct wf_sensor *new_sr)
311{
312 struct wf_sensor *sr;
313
314 mutex_lock(&wf_lock);
315 list_for_each_entry(sr, &wf_sensors, link) {
316 if (!strcmp(sr->name, new_sr->name)) {
317 printk(KERN_WARNING "windfarm: trying to register"
318 " duplicate sensor %s\n", sr->name);
319 mutex_unlock(&wf_lock);
320 return -EEXIST;
321 }
322 }
323 kref_init(&new_sr->ref);
324 list_add(&new_sr->link, &wf_sensors);
325
326 sysfs_attr_init(&new_sr->attr.attr);
327 new_sr->attr.attr.name = new_sr->name;
328 new_sr->attr.attr.mode = 0444;
329 new_sr->attr.show = wf_show_sensor;
330 new_sr->attr.store = NULL;
331 if (device_create_file(&wf_platform_device.dev, &new_sr->attr))
332 printk(KERN_WARNING "windfarm: device_create_file failed"
333 " for %s\n", new_sr->name);
334
335
336 DBG("wf: Registered sensor %s\n", new_sr->name);
337
338 wf_notify(WF_EVENT_NEW_SENSOR, new_sr);
339 mutex_unlock(&wf_lock);
340
341 return 0;
342}
343EXPORT_SYMBOL_GPL(wf_register_sensor);
344
345void wf_unregister_sensor(struct wf_sensor *sr)
346{
347 mutex_lock(&wf_lock);
348 list_del(&sr->link);
349 mutex_unlock(&wf_lock);
350
351 DBG("wf: Unregistered sensor %s\n", sr->name);
352
353 wf_put_sensor(sr);
354}
355EXPORT_SYMBOL_GPL(wf_unregister_sensor);
356
357struct wf_sensor * wf_find_sensor(const char *name)
358{
359 struct wf_sensor *sr;
360
361 mutex_lock(&wf_lock);
362 list_for_each_entry(sr, &wf_sensors, link) {
363 if (!strcmp(sr->name, name)) {
364 if (wf_get_sensor(sr))
365 sr = NULL;
366 mutex_unlock(&wf_lock);
367 return sr;
368 }
369 }
370 mutex_unlock(&wf_lock);
371 return NULL;
372}
373EXPORT_SYMBOL_GPL(wf_find_sensor);
374
375int wf_get_sensor(struct wf_sensor *sr)
376{
377 if (!try_module_get(sr->ops->owner))
378 return -ENODEV;
379 kref_get(&sr->ref);
380 return 0;
381}
382EXPORT_SYMBOL_GPL(wf_get_sensor);
383
384void wf_put_sensor(struct wf_sensor *sr)
385{
386 struct module *mod = sr->ops->owner;
387 kref_put(&sr->ref, wf_sensor_release);
388 module_put(mod);
389}
390EXPORT_SYMBOL_GPL(wf_put_sensor);
391
392
393
394
395
396
397int wf_register_client(struct notifier_block *nb)
398{
399 int rc;
400 struct wf_control *ct;
401 struct wf_sensor *sr;
402
403 mutex_lock(&wf_lock);
404 rc = blocking_notifier_chain_register(&wf_client_list, nb);
405 if (rc != 0)
406 goto bail;
407 wf_client_count++;
408 list_for_each_entry(ct, &wf_controls, link)
409 wf_notify(WF_EVENT_NEW_CONTROL, ct);
410 list_for_each_entry(sr, &wf_sensors, link)
411 wf_notify(WF_EVENT_NEW_SENSOR, sr);
412 if (wf_client_count == 1)
413 wf_start_thread();
414 bail:
415 mutex_unlock(&wf_lock);
416 return rc;
417}
418EXPORT_SYMBOL_GPL(wf_register_client);
419
420int wf_unregister_client(struct notifier_block *nb)
421{
422 mutex_lock(&wf_lock);
423 blocking_notifier_chain_unregister(&wf_client_list, nb);
424 wf_client_count++;
425 if (wf_client_count == 0)
426 wf_stop_thread();
427 mutex_unlock(&wf_lock);
428
429 return 0;
430}
431EXPORT_SYMBOL_GPL(wf_unregister_client);
432
433void wf_set_overtemp(void)
434{
435 mutex_lock(&wf_lock);
436 wf_overtemp++;
437 if (wf_overtemp == 1) {
438 printk(KERN_WARNING "windfarm: Overtemp condition detected !\n");
439 wf_overtemp_counter = 0;
440 wf_notify(WF_EVENT_OVERTEMP, NULL);
441 }
442 mutex_unlock(&wf_lock);
443}
444EXPORT_SYMBOL_GPL(wf_set_overtemp);
445
446void wf_clear_overtemp(void)
447{
448 mutex_lock(&wf_lock);
449 WARN_ON(wf_overtemp == 0);
450 if (wf_overtemp == 0) {
451 mutex_unlock(&wf_lock);
452 return;
453 }
454 wf_overtemp--;
455 if (wf_overtemp == 0) {
456 printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n");
457 wf_notify(WF_EVENT_NORMALTEMP, NULL);
458 }
459 mutex_unlock(&wf_lock);
460}
461EXPORT_SYMBOL_GPL(wf_clear_overtemp);
462
463int wf_is_overtemp(void)
464{
465 return (wf_overtemp != 0);
466}
467EXPORT_SYMBOL_GPL(wf_is_overtemp);
468
469static int __init windfarm_core_init(void)
470{
471 DBG("wf: core loaded\n");
472
473
474 if (of_machine_is_compatible("PowerMac7,2") ||
475 of_machine_is_compatible("PowerMac7,3") ||
476 of_machine_is_compatible("RackMac3,1"))
477 return -ENODEV;
478 platform_device_register(&wf_platform_device);
479 return 0;
480}
481
482static void __exit windfarm_core_exit(void)
483{
484 BUG_ON(wf_client_count != 0);
485
486 DBG("wf: core unloaded\n");
487
488 platform_device_unregister(&wf_platform_device);
489}
490
491
492module_init(windfarm_core_init);
493module_exit(windfarm_core_exit);
494
495MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
496MODULE_DESCRIPTION("Core component of PowerMac thermal control");
497MODULE_LICENSE("GPL");
498
499
