USB: dummy_hcd: change the default power budget
[linux-2.6] / drivers / macintosh / windfarm_core.c
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>
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
52 static LIST_HEAD(wf_controls);
53 static LIST_HEAD(wf_sensors);
54 static DEFINE_MUTEX(wf_lock);
55 static BLOCKING_NOTIFIER_HEAD(wf_client_list);
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
61 static struct platform_device wf_platform_device = {
62         .name   = "windfarm",
63 };
64
65 /*
66  * Utilities & tick thread
67  */
68
69 static inline void wf_notify(int event, void *param)
70 {
71         blocking_notifier_call_chain(&wf_client_list, event, param);
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,
84                                    argv, envp, UMH_WAIT_EXEC);
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
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                                 /* 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);
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
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);
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 /* This is really only for debugging... */
176 static 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
196 int 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                 /* the subsystem still does useful work without the file */
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 }
228 EXPORT_SYMBOL_GPL(wf_register_control);
229
230 void 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 }
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
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 }
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
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
308 int 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                 /* the subsystem still does useful work without the file */
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 }
340 EXPORT_SYMBOL_GPL(wf_register_sensor);
341
342 void 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 }
352 EXPORT_SYMBOL_GPL(wf_unregister_sensor);
353
354 struct 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 }
370 EXPORT_SYMBOL_GPL(wf_find_sensor);
371
372 int 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 }
379 EXPORT_SYMBOL_GPL(wf_get_sensor);
380
381 void 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 }
387 EXPORT_SYMBOL_GPL(wf_put_sensor);
388
389
390 /*
391  * Client & notification
392  */
393
394 int 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 }
415 EXPORT_SYMBOL_GPL(wf_register_client);
416
417 int 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 }
428 EXPORT_SYMBOL_GPL(wf_unregister_client);
429
430 void 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 }
441 EXPORT_SYMBOL_GPL(wf_set_overtemp);
442
443 void 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 }
458 EXPORT_SYMBOL_GPL(wf_clear_overtemp);
459
460 int wf_is_overtemp(void)
461 {
462         return (wf_overtemp != 0);
463 }
464 EXPORT_SYMBOL_GPL(wf_is_overtemp);
465
466 static int __init windfarm_core_init(void)
467 {
468         DBG("wf: core loaded\n");
469
470         /* Don't register on old machines that use therm_pm72 for now */
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
479 static 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
489 module_init(windfarm_core_init);
490 module_exit(windfarm_core_exit);
491
492 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
493 MODULE_DESCRIPTION("Core component of PowerMac thermal control");
494 MODULE_LICENSE("GPL");
495