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 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);
87 EXPORT_SYMBOL_GPL(wf_critical_overtemp);
89 static int wf_thread_func(void *data)
91 unsigned long next, delay;
95 DBG("wf: thread started\n");
98 while (!kthread_should_stop()) {
101 if (time_after_eq(jiffies, next)) {
102 wf_notify(WF_EVENT_TICK, NULL);
104 wf_overtemp_counter++;
105 /* 10 seconds overtemp, notify userland */
106 if (wf_overtemp_counter > 10)
107 wf_critical_overtemp();
108 /* 30 seconds, shutdown */
109 if (wf_overtemp_counter > 30) {
110 printk(KERN_ERR "windfarm: Overtemp "
112 " seconds, shutting down\n");
119 delay = next - jiffies;
121 schedule_timeout_interruptible(delay);
124 DBG("wf: thread stopped\n");
129 static void wf_start_thread(void)
131 wf_thread = kthread_run(wf_thread_func, NULL, "kwindfarm");
132 if (IS_ERR(wf_thread)) {
133 printk(KERN_ERR "windfarm: failed to create thread,err %ld\n",
140 static void wf_stop_thread(void)
143 kthread_stop(wf_thread);
151 static void wf_control_release(struct kref *kref)
153 struct wf_control *ct = container_of(kref, struct wf_control, ref);
155 DBG("wf: Deleting control %s\n", ct->name);
157 if (ct->ops && ct->ops->release)
158 ct->ops->release(ct);
163 static ssize_t wf_show_control(struct device *dev,
164 struct device_attribute *attr, char *buf)
166 struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
170 err = ctrl->ops->get_value(ctrl, &val);
173 return sprintf(buf, "%d\n", val);
176 /* This is really only for debugging... */
177 static ssize_t wf_store_control(struct device *dev,
178 struct device_attribute *attr,
179 const char *buf, size_t count)
181 struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
186 val = simple_strtoul(buf, &endp, 0);
187 while (endp < buf + count && (*endp == ' ' || *endp == '\n'))
189 if (endp - buf < count)
191 err = ctrl->ops->set_value(ctrl, val);
197 int wf_register_control(struct wf_control *new_ct)
199 struct wf_control *ct;
201 mutex_lock(&wf_lock);
202 list_for_each_entry(ct, &wf_controls, link) {
203 if (!strcmp(ct->name, new_ct->name)) {
204 printk(KERN_WARNING "windfarm: trying to register"
205 " duplicate control %s\n", ct->name);
206 mutex_unlock(&wf_lock);
210 kref_init(&new_ct->ref);
211 list_add(&new_ct->link, &wf_controls);
213 new_ct->attr.attr.name = new_ct->name;
214 new_ct->attr.attr.mode = 0644;
215 new_ct->attr.show = wf_show_control;
216 new_ct->attr.store = wf_store_control;
217 if (device_create_file(&wf_platform_device.dev, &new_ct->attr))
218 printk(KERN_WARNING "windfarm: device_create_file failed"
219 " for %s\n", new_ct->name);
220 /* the subsystem still does useful work without the file */
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 sysfs_attr_init(&new_sr->attr.attr);
326 new_sr->attr.attr.name = new_sr->name;
327 new_sr->attr.attr.mode = 0444;
328 new_sr->attr.show = wf_show_sensor;
329 new_sr->attr.store = NULL;
330 if (device_create_file(&wf_platform_device.dev, &new_sr->attr))
331 printk(KERN_WARNING "windfarm: device_create_file failed"
332 " for %s\n", new_sr->name);
333 /* the subsystem still does useful work without the file */
335 DBG("wf: Registered sensor %s\n", new_sr->name);
337 wf_notify(WF_EVENT_NEW_SENSOR, new_sr);
338 mutex_unlock(&wf_lock);
342 EXPORT_SYMBOL_GPL(wf_register_sensor);
344 void wf_unregister_sensor(struct wf_sensor *sr)
346 mutex_lock(&wf_lock);
348 mutex_unlock(&wf_lock);
350 DBG("wf: Unregistered sensor %s\n", sr->name);
354 EXPORT_SYMBOL_GPL(wf_unregister_sensor);
356 struct wf_sensor * wf_find_sensor(const char *name)
358 struct wf_sensor *sr;
360 mutex_lock(&wf_lock);
361 list_for_each_entry(sr, &wf_sensors, link) {
362 if (!strcmp(sr->name, name)) {
363 if (wf_get_sensor(sr))
365 mutex_unlock(&wf_lock);
369 mutex_unlock(&wf_lock);
372 EXPORT_SYMBOL_GPL(wf_find_sensor);
374 int wf_get_sensor(struct wf_sensor *sr)
376 if (!try_module_get(sr->ops->owner))
381 EXPORT_SYMBOL_GPL(wf_get_sensor);
383 void wf_put_sensor(struct wf_sensor *sr)
385 struct module *mod = sr->ops->owner;
386 kref_put(&sr->ref, wf_sensor_release);
389 EXPORT_SYMBOL_GPL(wf_put_sensor);
393 * Client & notification
396 int wf_register_client(struct notifier_block *nb)
399 struct wf_control *ct;
400 struct wf_sensor *sr;
402 mutex_lock(&wf_lock);
403 rc = blocking_notifier_chain_register(&wf_client_list, nb);
407 list_for_each_entry(ct, &wf_controls, link)
408 wf_notify(WF_EVENT_NEW_CONTROL, ct);
409 list_for_each_entry(sr, &wf_sensors, link)
410 wf_notify(WF_EVENT_NEW_SENSOR, sr);
411 if (wf_client_count == 1)
414 mutex_unlock(&wf_lock);
417 EXPORT_SYMBOL_GPL(wf_register_client);
419 int wf_unregister_client(struct notifier_block *nb)
421 mutex_lock(&wf_lock);
422 blocking_notifier_chain_unregister(&wf_client_list, nb);
424 if (wf_client_count == 0)
426 mutex_unlock(&wf_lock);
430 EXPORT_SYMBOL_GPL(wf_unregister_client);
432 void wf_set_overtemp(void)
434 mutex_lock(&wf_lock);
436 if (wf_overtemp == 1) {
437 printk(KERN_WARNING "windfarm: Overtemp condition detected !\n");
438 wf_overtemp_counter = 0;
439 wf_notify(WF_EVENT_OVERTEMP, NULL);
441 mutex_unlock(&wf_lock);
443 EXPORT_SYMBOL_GPL(wf_set_overtemp);
445 void wf_clear_overtemp(void)
447 mutex_lock(&wf_lock);
448 WARN_ON(wf_overtemp == 0);
449 if (wf_overtemp == 0) {
450 mutex_unlock(&wf_lock);
454 if (wf_overtemp == 0) {
455 printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n");
456 wf_notify(WF_EVENT_NORMALTEMP, NULL);
458 mutex_unlock(&wf_lock);
460 EXPORT_SYMBOL_GPL(wf_clear_overtemp);
462 int wf_is_overtemp(void)
464 return (wf_overtemp != 0);
466 EXPORT_SYMBOL_GPL(wf_is_overtemp);
468 static int __init windfarm_core_init(void)
470 DBG("wf: core loaded\n");
472 /* Don't register on old machines that use therm_pm72 for now */
473 if (of_machine_is_compatible("PowerMac7,2") ||
474 of_machine_is_compatible("PowerMac7,3") ||
475 of_machine_is_compatible("RackMac3,1"))
477 platform_device_register(&wf_platform_device);
481 static void __exit windfarm_core_exit(void)
483 BUG_ON(wf_client_count != 0);
485 DBG("wf: core unloaded\n");
487 platform_device_unregister(&wf_platform_device);
491 module_init(windfarm_core_init);
492 module_exit(windfarm_core_exit);
494 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
495 MODULE_DESCRIPTION("Core component of PowerMac thermal control");
496 MODULE_LICENSE("GPL");