blob: e947af982f93503b0e20bd321247e4c6770b3abe [file] [log] [blame]
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +11001/*
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/smp_lock.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>
Ingo Molnar837e9592006-01-14 16:18:45 +010036#include <linux/mutex.h>
Nigel Cunningham7dfb7102006-12-06 20:34:23 -080037#include <linux/freezer.h>
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +110038
Benjamin Herrenschmidtb55fafc2006-03-03 17:03:21 +110039#include <asm/prom.h>
40
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +110041#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);
Ingo Molnar837e9592006-01-14 16:18:45 +010055static DEFINE_MUTEX(wf_lock);
Alan Sterne041c682006-03-27 01:16:30 -080056static BLOCKING_NOTIFIER_HEAD(wf_client_list);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +110057static int wf_client_count;
58static unsigned int wf_overtemp;
59static unsigned int wf_overtemp_counter;
60struct task_struct *wf_thread;
61
Benjamin Herrenschmidtac171c42006-02-08 16:42:51 +110062static struct platform_device wf_platform_device = {
63 .name = "windfarm",
64};
65
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +110066/*
67 * Utilities & tick thread
68 */
69
70static inline void wf_notify(int event, void *param)
71{
Alan Sterne041c682006-03-27 01:16:30 -080072 blocking_notifier_call_chain(&wf_client_list, event, param);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +110073}
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, argv, envp, 0);
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 while(!kthread_should_stop()) {
97 try_to_freeze();
98
99 if (time_after_eq(jiffies, next)) {
100 wf_notify(WF_EVENT_TICK, NULL);
101 if (wf_overtemp) {
102 wf_overtemp_counter++;
103 /* 10 seconds overtemp, notify userland */
104 if (wf_overtemp_counter > 10)
105 wf_critical_overtemp();
106 /* 30 seconds, shutdown */
107 if (wf_overtemp_counter > 30) {
108 printk(KERN_ERR "windfarm: Overtemp "
109 "for more than 30"
110 " seconds, shutting down\n");
111 machine_power_off();
112 }
113 }
114 next += HZ;
115 }
116
117 delay = next - jiffies;
118 if (delay <= HZ)
119 schedule_timeout_interruptible(delay);
120
121 /* there should be no signal, but oh well */
122 if (signal_pending(current)) {
123 printk(KERN_WARNING "windfarm: thread got sigl !\n");
124 break;
125 }
126 }
127
128 DBG("wf: thread stopped\n");
129
130 return 0;
131}
132
133static void wf_start_thread(void)
134{
135 wf_thread = kthread_run(wf_thread_func, NULL, "kwindfarm");
136 if (IS_ERR(wf_thread)) {
137 printk(KERN_ERR "windfarm: failed to create thread,err %ld\n",
138 PTR_ERR(wf_thread));
139 wf_thread = NULL;
140 }
141}
142
143
144static void wf_stop_thread(void)
145{
146 if (wf_thread)
147 kthread_stop(wf_thread);
148 wf_thread = NULL;
149}
150
151/*
152 * Controls
153 */
154
155static void wf_control_release(struct kref *kref)
156{
157 struct wf_control *ct = container_of(kref, struct wf_control, ref);
158
159 DBG("wf: Deleting control %s\n", ct->name);
160
161 if (ct->ops && ct->ops->release)
162 ct->ops->release(ct);
163 else
164 kfree(ct);
165}
166
Benjamin Herrenschmidtac171c42006-02-08 16:42:51 +1100167static ssize_t wf_show_control(struct device *dev,
168 struct device_attribute *attr, char *buf)
169{
170 struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
171 s32 val = 0;
172 int err;
173
174 err = ctrl->ops->get_value(ctrl, &val);
175 if (err < 0)
176 return err;
177 return sprintf(buf, "%d\n", val);
178}
179
180/* This is really only for debugging... */
181static ssize_t wf_store_control(struct device *dev,
182 struct device_attribute *attr,
183 const char *buf, size_t count)
184{
185 struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
186 int val;
187 int err;
188 char *endp;
189
190 val = simple_strtoul(buf, &endp, 0);
191 while (endp < buf + count && (*endp == ' ' || *endp == '\n'))
192 ++endp;
193 if (endp - buf < count)
194 return -EINVAL;
195 err = ctrl->ops->set_value(ctrl, val);
196 if (err < 0)
197 return err;
198 return count;
199}
200
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100201int wf_register_control(struct wf_control *new_ct)
202{
203 struct wf_control *ct;
204
Ingo Molnar837e9592006-01-14 16:18:45 +0100205 mutex_lock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100206 list_for_each_entry(ct, &wf_controls, link) {
207 if (!strcmp(ct->name, new_ct->name)) {
208 printk(KERN_WARNING "windfarm: trying to register"
209 " duplicate control %s\n", ct->name);
Ingo Molnar837e9592006-01-14 16:18:45 +0100210 mutex_unlock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100211 return -EEXIST;
212 }
213 }
214 kref_init(&new_ct->ref);
215 list_add(&new_ct->link, &wf_controls);
216
Benjamin Herrenschmidtac171c42006-02-08 16:42:51 +1100217 new_ct->attr.attr.name = new_ct->name;
218 new_ct->attr.attr.owner = THIS_MODULE;
219 new_ct->attr.attr.mode = 0644;
220 new_ct->attr.show = wf_show_control;
221 new_ct->attr.store = wf_store_control;
222 device_create_file(&wf_platform_device.dev, &new_ct->attr);
223
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100224 DBG("wf: Registered control %s\n", new_ct->name);
225
226 wf_notify(WF_EVENT_NEW_CONTROL, new_ct);
Ingo Molnar837e9592006-01-14 16:18:45 +0100227 mutex_unlock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100228
229 return 0;
230}
231EXPORT_SYMBOL_GPL(wf_register_control);
232
233void wf_unregister_control(struct wf_control *ct)
234{
Ingo Molnar837e9592006-01-14 16:18:45 +0100235 mutex_lock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100236 list_del(&ct->link);
Ingo Molnar837e9592006-01-14 16:18:45 +0100237 mutex_unlock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100238
239 DBG("wf: Unregistered control %s\n", ct->name);
240
241 kref_put(&ct->ref, wf_control_release);
242}
243EXPORT_SYMBOL_GPL(wf_unregister_control);
244
245struct wf_control * wf_find_control(const char *name)
246{
247 struct wf_control *ct;
248
Ingo Molnar837e9592006-01-14 16:18:45 +0100249 mutex_lock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100250 list_for_each_entry(ct, &wf_controls, link) {
251 if (!strcmp(ct->name, name)) {
252 if (wf_get_control(ct))
253 ct = NULL;
Ingo Molnar837e9592006-01-14 16:18:45 +0100254 mutex_unlock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100255 return ct;
256 }
257 }
Ingo Molnar837e9592006-01-14 16:18:45 +0100258 mutex_unlock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100259 return NULL;
260}
261EXPORT_SYMBOL_GPL(wf_find_control);
262
263int wf_get_control(struct wf_control *ct)
264{
265 if (!try_module_get(ct->ops->owner))
266 return -ENODEV;
267 kref_get(&ct->ref);
268 return 0;
269}
270EXPORT_SYMBOL_GPL(wf_get_control);
271
272void wf_put_control(struct wf_control *ct)
273{
274 struct module *mod = ct->ops->owner;
275 kref_put(&ct->ref, wf_control_release);
276 module_put(mod);
277}
278EXPORT_SYMBOL_GPL(wf_put_control);
279
280
281/*
282 * Sensors
283 */
284
285
286static void wf_sensor_release(struct kref *kref)
287{
288 struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref);
289
290 DBG("wf: Deleting sensor %s\n", sr->name);
291
292 if (sr->ops && sr->ops->release)
293 sr->ops->release(sr);
294 else
295 kfree(sr);
296}
297
Benjamin Herrenschmidtac171c42006-02-08 16:42:51 +1100298static ssize_t wf_show_sensor(struct device *dev,
299 struct device_attribute *attr, char *buf)
300{
301 struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr);
302 s32 val = 0;
303 int err;
304
305 err = sens->ops->get_value(sens, &val);
306 if (err < 0)
307 return err;
308 return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val));
309}
310
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100311int wf_register_sensor(struct wf_sensor *new_sr)
312{
313 struct wf_sensor *sr;
314
Ingo Molnar837e9592006-01-14 16:18:45 +0100315 mutex_lock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100316 list_for_each_entry(sr, &wf_sensors, link) {
317 if (!strcmp(sr->name, new_sr->name)) {
318 printk(KERN_WARNING "windfarm: trying to register"
319 " duplicate sensor %s\n", sr->name);
Ingo Molnar837e9592006-01-14 16:18:45 +0100320 mutex_unlock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100321 return -EEXIST;
322 }
323 }
324 kref_init(&new_sr->ref);
325 list_add(&new_sr->link, &wf_sensors);
326
Benjamin Herrenschmidtac171c42006-02-08 16:42:51 +1100327 new_sr->attr.attr.name = new_sr->name;
328 new_sr->attr.attr.owner = THIS_MODULE;
329 new_sr->attr.attr.mode = 0444;
330 new_sr->attr.show = wf_show_sensor;
331 new_sr->attr.store = NULL;
332 device_create_file(&wf_platform_device.dev, &new_sr->attr);
333
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100334 DBG("wf: Registered sensor %s\n", new_sr->name);
335
336 wf_notify(WF_EVENT_NEW_SENSOR, new_sr);
Ingo Molnar837e9592006-01-14 16:18:45 +0100337 mutex_unlock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100338
339 return 0;
340}
341EXPORT_SYMBOL_GPL(wf_register_sensor);
342
343void wf_unregister_sensor(struct wf_sensor *sr)
344{
Ingo Molnar837e9592006-01-14 16:18:45 +0100345 mutex_lock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100346 list_del(&sr->link);
Ingo Molnar837e9592006-01-14 16:18:45 +0100347 mutex_unlock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100348
349 DBG("wf: Unregistered sensor %s\n", sr->name);
350
351 wf_put_sensor(sr);
352}
353EXPORT_SYMBOL_GPL(wf_unregister_sensor);
354
355struct wf_sensor * wf_find_sensor(const char *name)
356{
357 struct wf_sensor *sr;
358
Ingo Molnar837e9592006-01-14 16:18:45 +0100359 mutex_lock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100360 list_for_each_entry(sr, &wf_sensors, link) {
361 if (!strcmp(sr->name, name)) {
362 if (wf_get_sensor(sr))
363 sr = NULL;
Ingo Molnar837e9592006-01-14 16:18:45 +0100364 mutex_unlock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100365 return sr;
366 }
367 }
Ingo Molnar837e9592006-01-14 16:18:45 +0100368 mutex_unlock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100369 return NULL;
370}
371EXPORT_SYMBOL_GPL(wf_find_sensor);
372
373int wf_get_sensor(struct wf_sensor *sr)
374{
375 if (!try_module_get(sr->ops->owner))
376 return -ENODEV;
377 kref_get(&sr->ref);
378 return 0;
379}
380EXPORT_SYMBOL_GPL(wf_get_sensor);
381
382void wf_put_sensor(struct wf_sensor *sr)
383{
384 struct module *mod = sr->ops->owner;
385 kref_put(&sr->ref, wf_sensor_release);
386 module_put(mod);
387}
388EXPORT_SYMBOL_GPL(wf_put_sensor);
389
390
391/*
392 * Client & notification
393 */
394
395int wf_register_client(struct notifier_block *nb)
396{
397 int rc;
398 struct wf_control *ct;
399 struct wf_sensor *sr;
400
Ingo Molnar837e9592006-01-14 16:18:45 +0100401 mutex_lock(&wf_lock);
Alan Sterne041c682006-03-27 01:16:30 -0800402 rc = blocking_notifier_chain_register(&wf_client_list, nb);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100403 if (rc != 0)
404 goto bail;
405 wf_client_count++;
406 list_for_each_entry(ct, &wf_controls, link)
407 wf_notify(WF_EVENT_NEW_CONTROL, ct);
408 list_for_each_entry(sr, &wf_sensors, link)
409 wf_notify(WF_EVENT_NEW_SENSOR, sr);
410 if (wf_client_count == 1)
411 wf_start_thread();
412 bail:
Ingo Molnar837e9592006-01-14 16:18:45 +0100413 mutex_unlock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100414 return rc;
415}
416EXPORT_SYMBOL_GPL(wf_register_client);
417
418int wf_unregister_client(struct notifier_block *nb)
419{
Ingo Molnar837e9592006-01-14 16:18:45 +0100420 mutex_lock(&wf_lock);
Alan Sterne041c682006-03-27 01:16:30 -0800421 blocking_notifier_chain_unregister(&wf_client_list, nb);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100422 wf_client_count++;
423 if (wf_client_count == 0)
424 wf_stop_thread();
Ingo Molnar837e9592006-01-14 16:18:45 +0100425 mutex_unlock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100426
427 return 0;
428}
429EXPORT_SYMBOL_GPL(wf_unregister_client);
430
431void wf_set_overtemp(void)
432{
Ingo Molnar837e9592006-01-14 16:18:45 +0100433 mutex_lock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100434 wf_overtemp++;
435 if (wf_overtemp == 1) {
436 printk(KERN_WARNING "windfarm: Overtemp condition detected !\n");
437 wf_overtemp_counter = 0;
438 wf_notify(WF_EVENT_OVERTEMP, NULL);
439 }
Ingo Molnar837e9592006-01-14 16:18:45 +0100440 mutex_unlock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100441}
442EXPORT_SYMBOL_GPL(wf_set_overtemp);
443
444void wf_clear_overtemp(void)
445{
Ingo Molnar837e9592006-01-14 16:18:45 +0100446 mutex_lock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100447 WARN_ON(wf_overtemp == 0);
448 if (wf_overtemp == 0) {
Ingo Molnar837e9592006-01-14 16:18:45 +0100449 mutex_unlock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100450 return;
451 }
452 wf_overtemp--;
453 if (wf_overtemp == 0) {
454 printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n");
455 wf_notify(WF_EVENT_NORMALTEMP, NULL);
456 }
Ingo Molnar837e9592006-01-14 16:18:45 +0100457 mutex_unlock(&wf_lock);
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100458}
459EXPORT_SYMBOL_GPL(wf_clear_overtemp);
460
461int wf_is_overtemp(void)
462{
463 return (wf_overtemp != 0);
464}
465EXPORT_SYMBOL_GPL(wf_is_overtemp);
466
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100467static int __init windfarm_core_init(void)
468{
469 DBG("wf: core loaded\n");
470
Benjamin Herrenschmidtb55fafc2006-03-03 17:03:21 +1100471 /* Don't register on old machines that use therm_pm72 for now */
472 if (machine_is_compatible("PowerMac7,2") ||
473 machine_is_compatible("PowerMac7,3") ||
474 machine_is_compatible("RackMac3,1"))
475 return -ENODEV;
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +1100476 platform_device_register(&wf_platform_device);
477 return 0;
478}
479
480static void __exit windfarm_core_exit(void)
481{
482 BUG_ON(wf_client_count != 0);
483
484 DBG("wf: core unloaded\n");
485
486 platform_device_unregister(&wf_platform_device);
487}
488
489
490module_init(windfarm_core_init);
491module_exit(windfarm_core_exit);
492
493MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
494MODULE_DESCRIPTION("Core component of PowerMac thermal control");
495MODULE_LICENSE("GPL");
496