header cleaning: don't include smp_lock.h when not used
[linux-3.10.git] / 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, 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()) {
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
118                 /* there should be no non-suspend signal, but oh well */
119                 if (signal_pending(current) && !try_to_freeze()) {
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
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
198 int wf_register_control(struct wf_control *new_ct)
199 {
200         struct wf_control *ct;
201
202         mutex_lock(&wf_lock);
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);
207                         mutex_unlock(&wf_lock);
208                         return -EEXIST;
209                 }
210         }
211         kref_init(&new_ct->ref);
212         list_add(&new_ct->link, &wf_controls);
213
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
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.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
331         DBG("wf: Registered sensor %s\n", new_sr->name);
332
333         wf_notify(WF_EVENT_NEW_SENSOR, new_sr);
334         mutex_unlock(&wf_lock);
335
336         return 0;
337 }
338 EXPORT_SYMBOL_GPL(wf_register_sensor);
339
340 void wf_unregister_sensor(struct wf_sensor *sr)
341 {
342         mutex_lock(&wf_lock);
343         list_del(&sr->link);
344         mutex_unlock(&wf_lock);
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
356         mutex_lock(&wf_lock);
357         list_for_each_entry(sr, &wf_sensors, link) {
358                 if (!strcmp(sr->name, name)) {
359                         if (wf_get_sensor(sr))
360                                 sr = NULL;
361                         mutex_unlock(&wf_lock);
362                         return sr;
363                 }
364         }
365         mutex_unlock(&wf_lock);
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
398         mutex_lock(&wf_lock);
399         rc = blocking_notifier_chain_register(&wf_client_list, nb);
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:
410         mutex_unlock(&wf_lock);
411         return rc;
412 }
413 EXPORT_SYMBOL_GPL(wf_register_client);
414
415 int wf_unregister_client(struct notifier_block *nb)
416 {
417         mutex_lock(&wf_lock);
418         blocking_notifier_chain_unregister(&wf_client_list, nb);
419         wf_client_count++;
420         if (wf_client_count == 0)
421                 wf_stop_thread();
422         mutex_unlock(&wf_lock);
423
424         return 0;
425 }
426 EXPORT_SYMBOL_GPL(wf_unregister_client);
427
428 void wf_set_overtemp(void)
429 {
430         mutex_lock(&wf_lock);
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         }
437         mutex_unlock(&wf_lock);
438 }
439 EXPORT_SYMBOL_GPL(wf_set_overtemp);
440
441 void wf_clear_overtemp(void)
442 {
443         mutex_lock(&wf_lock);
444         WARN_ON(wf_overtemp == 0);
445         if (wf_overtemp == 0) {
446                 mutex_unlock(&wf_lock);
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         }
454         mutex_unlock(&wf_lock);
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
464 static int __init windfarm_core_init(void)
465 {
466         DBG("wf: core loaded\n");
467
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;
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