2 * Windfarm PowerMac thermal control. Core
4 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
5 * <benh@kernel.crashing.org>
7 * Released under the term of the GNU GPL v2.
9 * This core code tracks the list of sensors & controls, register
10 * clients, and holds the kernel thread used for control.
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
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
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>
48 #define DBG(args...) printk(args)
50 #define DBG(args...) do { } while(0)
53 static LIST_HEAD(wf_controls);
54 static LIST_HEAD(wf_sensors);
55 static DEFINE_MUTEX(wf_lock);
56 static BLOCKING_NOTIFIER_HEAD(wf_client_list);
57 static int wf_client_count;
58 static unsigned int wf_overtemp;
59 static unsigned int wf_overtemp_counter;
60 struct task_struct *wf_thread;
62 static struct platform_device wf_platform_device = {
67 * Utilities & tick thread
70 static inline void wf_notify(int event, void *param)
72 blocking_notifier_call_chain(&wf_client_list, event, param);
75 static int wf_critical_overtemp(void)
77 static char * critical_overtemp_path = "/sbin/critical_overtemp";
78 char *argv[] = { critical_overtemp_path, NULL };
79 static char *envp[] = { "HOME=/",
81 "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
84 return call_usermodehelper(critical_overtemp_path,
85 argv, envp, UMH_WAIT_EXEC);
88 static int wf_thread_func(void *data)
90 unsigned long next, delay;
94 DBG("wf: thread started\n");
97 while (!kthread_should_stop()) {
100 if (time_after_eq(jiffies, next)) {
101 wf_notify(WF_EVENT_TICK, NULL);
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 "
111 " seconds, shutting down\n");
118 delay = next - jiffies;
120 schedule_timeout_interruptible(delay);
123 DBG("wf: thread stopped\n");
128 static void wf_start_thread(void)
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",
139 static void wf_stop_thread(void)
142 kthread_stop(wf_thread);
150 static void wf_control_release(struct kref *kref)
152 struct wf_control *ct = container_of(kref, struct wf_control, ref);
154 DBG("wf: Deleting control %s\n", ct->name);
156 if (ct->ops && ct->ops->release)
157 ct->ops->release(ct);
162 static ssize_t wf_show_control(struct device *dev,
163 struct device_attribute *attr, char *buf)
165 struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
170 err = ctrl->ops->get_value(ctrl, &val);
173 return sprintf(buf, "<HW FAULT>\n");
177 case WF_CONTROL_RPM_FAN:
180 case WF_CONTROL_PWM_FAN:
186 return sprintf(buf, "%d%s\n", val, typestr);
189 /* This is really only for debugging... */
190 static ssize_t wf_store_control(struct device *dev,
191 struct device_attribute *attr,
192 const char *buf, size_t count)
194 struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
199 val = simple_strtoul(buf, &endp, 0);
200 while (endp < buf + count && (*endp == ' ' || *endp == '\n'))
202 if (endp - buf < count)
204 err = ctrl->ops->set_value(ctrl, val);
210 int wf_register_control(struct wf_control *new_ct)
212 struct wf_control *ct;
214 mutex_lock(&wf_lock);
215 list_for_each_entry(ct, &wf_controls, link) {
216 if (!strcmp(ct->name, new_ct->name)) {
217 printk(KERN_WARNING "windfarm: trying to register"
218 " duplicate control %s\n", ct->name);
219 mutex_unlock(&wf_lock);
223 kref_init(&new_ct->ref);
224 list_add(&new_ct->link, &wf_controls);
226 sysfs_attr_init(&new_ct->attr.attr);
227 new_ct->attr.attr.name = new_ct->name;
228 new_ct->attr.attr.mode = 0644;
229 new_ct->attr.show = wf_show_control;
230 new_ct->attr.store = wf_store_control;
231 if (device_create_file(&wf_platform_device.dev, &new_ct->attr))
232 printk(KERN_WARNING "windfarm: device_create_file failed"
233 " for %s\n", new_ct->name);
234 /* the subsystem still does useful work without the file */
236 DBG("wf: Registered control %s\n", new_ct->name);
238 wf_notify(WF_EVENT_NEW_CONTROL, new_ct);
239 mutex_unlock(&wf_lock);
243 EXPORT_SYMBOL_GPL(wf_register_control);
245 void wf_unregister_control(struct wf_control *ct)
247 mutex_lock(&wf_lock);
249 mutex_unlock(&wf_lock);
251 DBG("wf: Unregistered control %s\n", ct->name);
253 kref_put(&ct->ref, wf_control_release);
255 EXPORT_SYMBOL_GPL(wf_unregister_control);
257 struct wf_control * wf_find_control(const char *name)
259 struct wf_control *ct;
261 mutex_lock(&wf_lock);
262 list_for_each_entry(ct, &wf_controls, link) {
263 if (!strcmp(ct->name, name)) {
264 if (wf_get_control(ct))
266 mutex_unlock(&wf_lock);
270 mutex_unlock(&wf_lock);
273 EXPORT_SYMBOL_GPL(wf_find_control);
275 int wf_get_control(struct wf_control *ct)
277 if (!try_module_get(ct->ops->owner))
282 EXPORT_SYMBOL_GPL(wf_get_control);
284 void wf_put_control(struct wf_control *ct)
286 struct module *mod = ct->ops->owner;
287 kref_put(&ct->ref, wf_control_release);
290 EXPORT_SYMBOL_GPL(wf_put_control);
298 static void wf_sensor_release(struct kref *kref)
300 struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref);
302 DBG("wf: Deleting sensor %s\n", sr->name);
304 if (sr->ops && sr->ops->release)
305 sr->ops->release(sr);
310 static ssize_t wf_show_sensor(struct device *dev,
311 struct device_attribute *attr, char *buf)
313 struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr);
317 err = sens->ops->get_value(sens, &val);
320 return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val));
323 int wf_register_sensor(struct wf_sensor *new_sr)
325 struct wf_sensor *sr;
327 mutex_lock(&wf_lock);
328 list_for_each_entry(sr, &wf_sensors, link) {
329 if (!strcmp(sr->name, new_sr->name)) {
330 printk(KERN_WARNING "windfarm: trying to register"
331 " duplicate sensor %s\n", sr->name);
332 mutex_unlock(&wf_lock);
336 kref_init(&new_sr->ref);
337 list_add(&new_sr->link, &wf_sensors);
339 sysfs_attr_init(&new_sr->attr.attr);
340 new_sr->attr.attr.name = new_sr->name;
341 new_sr->attr.attr.mode = 0444;
342 new_sr->attr.show = wf_show_sensor;
343 new_sr->attr.store = NULL;
344 if (device_create_file(&wf_platform_device.dev, &new_sr->attr))
345 printk(KERN_WARNING "windfarm: device_create_file failed"
346 " for %s\n", new_sr->name);
347 /* the subsystem still does useful work without the file */
349 DBG("wf: Registered sensor %s\n", new_sr->name);
351 wf_notify(WF_EVENT_NEW_SENSOR, new_sr);
352 mutex_unlock(&wf_lock);
356 EXPORT_SYMBOL_GPL(wf_register_sensor);
358 void wf_unregister_sensor(struct wf_sensor *sr)
360 mutex_lock(&wf_lock);
362 mutex_unlock(&wf_lock);
364 DBG("wf: Unregistered sensor %s\n", sr->name);
368 EXPORT_SYMBOL_GPL(wf_unregister_sensor);
370 struct wf_sensor * wf_find_sensor(const char *name)
372 struct wf_sensor *sr;
374 mutex_lock(&wf_lock);
375 list_for_each_entry(sr, &wf_sensors, link) {
376 if (!strcmp(sr->name, name)) {
377 if (wf_get_sensor(sr))
379 mutex_unlock(&wf_lock);
383 mutex_unlock(&wf_lock);
386 EXPORT_SYMBOL_GPL(wf_find_sensor);
388 int wf_get_sensor(struct wf_sensor *sr)
390 if (!try_module_get(sr->ops->owner))
395 EXPORT_SYMBOL_GPL(wf_get_sensor);
397 void wf_put_sensor(struct wf_sensor *sr)
399 struct module *mod = sr->ops->owner;
400 kref_put(&sr->ref, wf_sensor_release);
403 EXPORT_SYMBOL_GPL(wf_put_sensor);
407 * Client & notification
410 int wf_register_client(struct notifier_block *nb)
413 struct wf_control *ct;
414 struct wf_sensor *sr;
416 mutex_lock(&wf_lock);
417 rc = blocking_notifier_chain_register(&wf_client_list, nb);
421 list_for_each_entry(ct, &wf_controls, link)
422 wf_notify(WF_EVENT_NEW_CONTROL, ct);
423 list_for_each_entry(sr, &wf_sensors, link)
424 wf_notify(WF_EVENT_NEW_SENSOR, sr);
425 if (wf_client_count == 1)
428 mutex_unlock(&wf_lock);
431 EXPORT_SYMBOL_GPL(wf_register_client);
433 int wf_unregister_client(struct notifier_block *nb)
435 mutex_lock(&wf_lock);
436 blocking_notifier_chain_unregister(&wf_client_list, nb);
438 if (wf_client_count == 0)
440 mutex_unlock(&wf_lock);
444 EXPORT_SYMBOL_GPL(wf_unregister_client);
446 void wf_set_overtemp(void)
448 mutex_lock(&wf_lock);
450 if (wf_overtemp == 1) {
451 printk(KERN_WARNING "windfarm: Overtemp condition detected !\n");
452 wf_overtemp_counter = 0;
453 wf_notify(WF_EVENT_OVERTEMP, NULL);
455 mutex_unlock(&wf_lock);
457 EXPORT_SYMBOL_GPL(wf_set_overtemp);
459 void wf_clear_overtemp(void)
461 mutex_lock(&wf_lock);
462 WARN_ON(wf_overtemp == 0);
463 if (wf_overtemp == 0) {
464 mutex_unlock(&wf_lock);
468 if (wf_overtemp == 0) {
469 printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n");
470 wf_notify(WF_EVENT_NORMALTEMP, NULL);
472 mutex_unlock(&wf_lock);
474 EXPORT_SYMBOL_GPL(wf_clear_overtemp);
476 int wf_is_overtemp(void)
478 return (wf_overtemp != 0);
480 EXPORT_SYMBOL_GPL(wf_is_overtemp);
482 static int __init windfarm_core_init(void)
484 DBG("wf: core loaded\n");
486 platform_device_register(&wf_platform_device);
490 static void __exit windfarm_core_exit(void)
492 BUG_ON(wf_client_count != 0);
494 DBG("wf: core unloaded\n");
496 platform_device_unregister(&wf_platform_device);
500 module_init(windfarm_core_init);
501 module_exit(windfarm_core_exit);
503 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
504 MODULE_DESCRIPTION("Core component of PowerMac thermal control");
505 MODULE_LICENSE("GPL");