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/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>
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 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, argv, envp, 0);
86 EXPORT_SYMBOL_GPL(wf_critical_overtemp);
88 static int wf_thread_func(void *data)
90 unsigned long next, delay;
94 DBG("wf: thread started\n");
96 while(!kthread_should_stop()) {
97 if (time_after_eq(jiffies, next)) {
98 wf_notify(WF_EVENT_TICK, NULL);
100 wf_overtemp_counter++;
101 /* 10 seconds overtemp, notify userland */
102 if (wf_overtemp_counter > 10)
103 wf_critical_overtemp();
104 /* 30 seconds, shutdown */
105 if (wf_overtemp_counter > 30) {
106 printk(KERN_ERR "windfarm: Overtemp "
108 " seconds, shutting down\n");
115 delay = next - jiffies;
117 schedule_timeout_interruptible(delay);
119 /* there should be no non-suspend signal, but oh well */
120 if (signal_pending(current) && !try_to_freeze()) {
121 printk(KERN_WARNING "windfarm: thread got sigl !\n");
126 DBG("wf: thread stopped\n");
131 static void wf_start_thread(void)
133 wf_thread = kthread_run(wf_thread_func, NULL, "kwindfarm");
134 if (IS_ERR(wf_thread)) {
135 printk(KERN_ERR "windfarm: failed to create thread,err %ld\n",
142 static void wf_stop_thread(void)
145 kthread_stop(wf_thread);
153 static void wf_control_release(struct kref *kref)
155 struct wf_control *ct = container_of(kref, struct wf_control, ref);
157 DBG("wf: Deleting control %s\n", ct->name);
159 if (ct->ops && ct->ops->release)
160 ct->ops->release(ct);
165 static ssize_t wf_show_control(struct device *dev,
166 struct device_attribute *attr, char *buf)
168 struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
172 err = ctrl->ops->get_value(ctrl, &val);
175 return sprintf(buf, "%d\n", val);
178 /* This is really only for debugging... */
179 static ssize_t wf_store_control(struct device *dev,
180 struct device_attribute *attr,
181 const char *buf, size_t count)
183 struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
188 val = simple_strtoul(buf, &endp, 0);
189 while (endp < buf + count && (*endp == ' ' || *endp == '\n'))
191 if (endp - buf < count)
193 err = ctrl->ops->set_value(ctrl, val);
199 int wf_register_control(struct wf_control *new_ct)
201 struct wf_control *ct;
203 mutex_lock(&wf_lock);
204 list_for_each_entry(ct, &wf_controls, link) {
205 if (!strcmp(ct->name, new_ct->name)) {
206 printk(KERN_WARNING "windfarm: trying to register"
207 " duplicate control %s\n", ct->name);
208 mutex_unlock(&wf_lock);
212 kref_init(&new_ct->ref);
213 list_add(&new_ct->link, &wf_controls);
215 new_ct->attr.attr.name = new_ct->name;
216 new_ct->attr.attr.owner = THIS_MODULE;
217 new_ct->attr.attr.mode = 0644;
218 new_ct->attr.show = wf_show_control;
219 new_ct->attr.store = wf_store_control;
220 device_create_file(&wf_platform_device.dev, &new_ct->attr);
222 DBG("wf: Registered control %s\n", new_ct->name);
224 wf_notify(WF_EVENT_NEW_CONTROL, new_ct);
225 mutex_unlock(&wf_lock);
229 EXPORT_SYMBOL_GPL(wf_register_control);
231 void wf_unregister_control(struct wf_control *ct)
233 mutex_lock(&wf_lock);
235 mutex_unlock(&wf_lock);
237 DBG("wf: Unregistered control %s\n", ct->name);
239 kref_put(&ct->ref, wf_control_release);
241 EXPORT_SYMBOL_GPL(wf_unregister_control);
243 struct wf_control * wf_find_control(const char *name)
245 struct wf_control *ct;
247 mutex_lock(&wf_lock);
248 list_for_each_entry(ct, &wf_controls, link) {
249 if (!strcmp(ct->name, name)) {
250 if (wf_get_control(ct))
252 mutex_unlock(&wf_lock);
256 mutex_unlock(&wf_lock);
259 EXPORT_SYMBOL_GPL(wf_find_control);
261 int wf_get_control(struct wf_control *ct)
263 if (!try_module_get(ct->ops->owner))
268 EXPORT_SYMBOL_GPL(wf_get_control);
270 void wf_put_control(struct wf_control *ct)
272 struct module *mod = ct->ops->owner;
273 kref_put(&ct->ref, wf_control_release);
276 EXPORT_SYMBOL_GPL(wf_put_control);
284 static void wf_sensor_release(struct kref *kref)
286 struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref);
288 DBG("wf: Deleting sensor %s\n", sr->name);
290 if (sr->ops && sr->ops->release)
291 sr->ops->release(sr);
296 static ssize_t wf_show_sensor(struct device *dev,
297 struct device_attribute *attr, char *buf)
299 struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr);
303 err = sens->ops->get_value(sens, &val);
306 return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val));
309 int wf_register_sensor(struct wf_sensor *new_sr)
311 struct wf_sensor *sr;
313 mutex_lock(&wf_lock);
314 list_for_each_entry(sr, &wf_sensors, link) {
315 if (!strcmp(sr->name, new_sr->name)) {
316 printk(KERN_WARNING "windfarm: trying to register"
317 " duplicate sensor %s\n", sr->name);
318 mutex_unlock(&wf_lock);
322 kref_init(&new_sr->ref);
323 list_add(&new_sr->link, &wf_sensors);
325 new_sr->attr.attr.name = new_sr->name;
326 new_sr->attr.attr.owner = THIS_MODULE;
327 new_sr->attr.attr.mode = 0444;
328 new_sr->attr.show = wf_show_sensor;
329 new_sr->attr.store = NULL;
330 device_create_file(&wf_platform_device.dev, &new_sr->attr);
332 DBG("wf: Registered sensor %s\n", new_sr->name);
334 wf_notify(WF_EVENT_NEW_SENSOR, new_sr);
335 mutex_unlock(&wf_lock);
339 EXPORT_SYMBOL_GPL(wf_register_sensor);
341 void wf_unregister_sensor(struct wf_sensor *sr)
343 mutex_lock(&wf_lock);
345 mutex_unlock(&wf_lock);
347 DBG("wf: Unregistered sensor %s\n", sr->name);
351 EXPORT_SYMBOL_GPL(wf_unregister_sensor);
353 struct wf_sensor * wf_find_sensor(const char *name)
355 struct wf_sensor *sr;
357 mutex_lock(&wf_lock);
358 list_for_each_entry(sr, &wf_sensors, link) {
359 if (!strcmp(sr->name, name)) {
360 if (wf_get_sensor(sr))
362 mutex_unlock(&wf_lock);
366 mutex_unlock(&wf_lock);
369 EXPORT_SYMBOL_GPL(wf_find_sensor);
371 int wf_get_sensor(struct wf_sensor *sr)
373 if (!try_module_get(sr->ops->owner))
378 EXPORT_SYMBOL_GPL(wf_get_sensor);
380 void wf_put_sensor(struct wf_sensor *sr)
382 struct module *mod = sr->ops->owner;
383 kref_put(&sr->ref, wf_sensor_release);
386 EXPORT_SYMBOL_GPL(wf_put_sensor);
390 * Client & notification
393 int wf_register_client(struct notifier_block *nb)
396 struct wf_control *ct;
397 struct wf_sensor *sr;
399 mutex_lock(&wf_lock);
400 rc = blocking_notifier_chain_register(&wf_client_list, nb);
404 list_for_each_entry(ct, &wf_controls, link)
405 wf_notify(WF_EVENT_NEW_CONTROL, ct);
406 list_for_each_entry(sr, &wf_sensors, link)
407 wf_notify(WF_EVENT_NEW_SENSOR, sr);
408 if (wf_client_count == 1)
411 mutex_unlock(&wf_lock);
414 EXPORT_SYMBOL_GPL(wf_register_client);
416 int wf_unregister_client(struct notifier_block *nb)
418 mutex_lock(&wf_lock);
419 blocking_notifier_chain_unregister(&wf_client_list, nb);
421 if (wf_client_count == 0)
423 mutex_unlock(&wf_lock);
427 EXPORT_SYMBOL_GPL(wf_unregister_client);
429 void wf_set_overtemp(void)
431 mutex_lock(&wf_lock);
433 if (wf_overtemp == 1) {
434 printk(KERN_WARNING "windfarm: Overtemp condition detected !\n");
435 wf_overtemp_counter = 0;
436 wf_notify(WF_EVENT_OVERTEMP, NULL);
438 mutex_unlock(&wf_lock);
440 EXPORT_SYMBOL_GPL(wf_set_overtemp);
442 void wf_clear_overtemp(void)
444 mutex_lock(&wf_lock);
445 WARN_ON(wf_overtemp == 0);
446 if (wf_overtemp == 0) {
447 mutex_unlock(&wf_lock);
451 if (wf_overtemp == 0) {
452 printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n");
453 wf_notify(WF_EVENT_NORMALTEMP, NULL);
455 mutex_unlock(&wf_lock);
457 EXPORT_SYMBOL_GPL(wf_clear_overtemp);
459 int wf_is_overtemp(void)
461 return (wf_overtemp != 0);
463 EXPORT_SYMBOL_GPL(wf_is_overtemp);
465 static int __init windfarm_core_init(void)
467 DBG("wf: core loaded\n");
469 /* Don't register on old machines that use therm_pm72 for now */
470 if (machine_is_compatible("PowerMac7,2") ||
471 machine_is_compatible("PowerMac7,3") ||
472 machine_is_compatible("RackMac3,1"))
474 platform_device_register(&wf_platform_device);
478 static void __exit windfarm_core_exit(void)
480 BUG_ON(wf_client_count != 0);
482 DBG("wf: core unloaded\n");
484 platform_device_unregister(&wf_platform_device);
488 module_init(windfarm_core_init);
489 module_exit(windfarm_core_exit);
491 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
492 MODULE_DESCRIPTION("Core component of PowerMac thermal control");
493 MODULE_LICENSE("GPL");