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>
45 #define DBG(args...) printk(args)
47 #define DBG(args...) do { } while(0)
50 static LIST_HEAD(wf_controls
);
51 static LIST_HEAD(wf_sensors
);
52 static DEFINE_MUTEX(wf_lock
);
53 static struct notifier_block
*wf_client_list
;
54 static int wf_client_count
;
55 static unsigned int wf_overtemp
;
56 static unsigned int wf_overtemp_counter
;
57 struct task_struct
*wf_thread
;
60 * Utilities & tick thread
63 static inline void wf_notify(int event
, void *param
)
65 notifier_call_chain(&wf_client_list
, event
, param
);
68 int wf_critical_overtemp(void)
70 static char * critical_overtemp_path
= "/sbin/critical_overtemp";
71 char *argv
[] = { critical_overtemp_path
, NULL
};
72 static char *envp
[] = { "HOME=/",
74 "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
77 return call_usermodehelper(critical_overtemp_path
, argv
, envp
, 0);
79 EXPORT_SYMBOL_GPL(wf_critical_overtemp
);
81 static int wf_thread_func(void *data
)
83 unsigned long next
, delay
;
87 DBG("wf: thread started\n");
89 while(!kthread_should_stop()) {
92 if (time_after_eq(jiffies
, next
)) {
93 wf_notify(WF_EVENT_TICK
, NULL
);
95 wf_overtemp_counter
++;
96 /* 10 seconds overtemp, notify userland */
97 if (wf_overtemp_counter
> 10)
98 wf_critical_overtemp();
99 /* 30 seconds, shutdown */
100 if (wf_overtemp_counter
> 30) {
101 printk(KERN_ERR
"windfarm: Overtemp "
103 " seconds, shutting down\n");
110 delay
= next
- jiffies
;
112 schedule_timeout_interruptible(delay
);
114 /* there should be no signal, but oh well */
115 if (signal_pending(current
)) {
116 printk(KERN_WARNING
"windfarm: thread got sigl !\n");
121 DBG("wf: thread stopped\n");
126 static void wf_start_thread(void)
128 wf_thread
= kthread_run(wf_thread_func
, NULL
, "kwindfarm");
129 if (IS_ERR(wf_thread
)) {
130 printk(KERN_ERR
"windfarm: failed to create thread,err %ld\n",
137 static void wf_stop_thread(void)
140 kthread_stop(wf_thread
);
148 static void wf_control_release(struct kref
*kref
)
150 struct wf_control
*ct
= container_of(kref
, struct wf_control
, ref
);
152 DBG("wf: Deleting control %s\n", ct
->name
);
154 if (ct
->ops
&& ct
->ops
->release
)
155 ct
->ops
->release(ct
);
160 int wf_register_control(struct wf_control
*new_ct
)
162 struct wf_control
*ct
;
164 mutex_lock(&wf_lock
);
165 list_for_each_entry(ct
, &wf_controls
, link
) {
166 if (!strcmp(ct
->name
, new_ct
->name
)) {
167 printk(KERN_WARNING
"windfarm: trying to register"
168 " duplicate control %s\n", ct
->name
);
169 mutex_unlock(&wf_lock
);
173 kref_init(&new_ct
->ref
);
174 list_add(&new_ct
->link
, &wf_controls
);
176 DBG("wf: Registered control %s\n", new_ct
->name
);
178 wf_notify(WF_EVENT_NEW_CONTROL
, new_ct
);
179 mutex_unlock(&wf_lock
);
183 EXPORT_SYMBOL_GPL(wf_register_control
);
185 void wf_unregister_control(struct wf_control
*ct
)
187 mutex_lock(&wf_lock
);
189 mutex_unlock(&wf_lock
);
191 DBG("wf: Unregistered control %s\n", ct
->name
);
193 kref_put(&ct
->ref
, wf_control_release
);
195 EXPORT_SYMBOL_GPL(wf_unregister_control
);
197 struct wf_control
* wf_find_control(const char *name
)
199 struct wf_control
*ct
;
201 mutex_lock(&wf_lock
);
202 list_for_each_entry(ct
, &wf_controls
, link
) {
203 if (!strcmp(ct
->name
, name
)) {
204 if (wf_get_control(ct
))
206 mutex_unlock(&wf_lock
);
210 mutex_unlock(&wf_lock
);
213 EXPORT_SYMBOL_GPL(wf_find_control
);
215 int wf_get_control(struct wf_control
*ct
)
217 if (!try_module_get(ct
->ops
->owner
))
222 EXPORT_SYMBOL_GPL(wf_get_control
);
224 void wf_put_control(struct wf_control
*ct
)
226 struct module
*mod
= ct
->ops
->owner
;
227 kref_put(&ct
->ref
, wf_control_release
);
230 EXPORT_SYMBOL_GPL(wf_put_control
);
238 static void wf_sensor_release(struct kref
*kref
)
240 struct wf_sensor
*sr
= container_of(kref
, struct wf_sensor
, ref
);
242 DBG("wf: Deleting sensor %s\n", sr
->name
);
244 if (sr
->ops
&& sr
->ops
->release
)
245 sr
->ops
->release(sr
);
250 int wf_register_sensor(struct wf_sensor
*new_sr
)
252 struct wf_sensor
*sr
;
254 mutex_lock(&wf_lock
);
255 list_for_each_entry(sr
, &wf_sensors
, link
) {
256 if (!strcmp(sr
->name
, new_sr
->name
)) {
257 printk(KERN_WARNING
"windfarm: trying to register"
258 " duplicate sensor %s\n", sr
->name
);
259 mutex_unlock(&wf_lock
);
263 kref_init(&new_sr
->ref
);
264 list_add(&new_sr
->link
, &wf_sensors
);
266 DBG("wf: Registered sensor %s\n", new_sr
->name
);
268 wf_notify(WF_EVENT_NEW_SENSOR
, new_sr
);
269 mutex_unlock(&wf_lock
);
273 EXPORT_SYMBOL_GPL(wf_register_sensor
);
275 void wf_unregister_sensor(struct wf_sensor
*sr
)
277 mutex_lock(&wf_lock
);
279 mutex_unlock(&wf_lock
);
281 DBG("wf: Unregistered sensor %s\n", sr
->name
);
285 EXPORT_SYMBOL_GPL(wf_unregister_sensor
);
287 struct wf_sensor
* wf_find_sensor(const char *name
)
289 struct wf_sensor
*sr
;
291 mutex_lock(&wf_lock
);
292 list_for_each_entry(sr
, &wf_sensors
, link
) {
293 if (!strcmp(sr
->name
, name
)) {
294 if (wf_get_sensor(sr
))
296 mutex_unlock(&wf_lock
);
300 mutex_unlock(&wf_lock
);
303 EXPORT_SYMBOL_GPL(wf_find_sensor
);
305 int wf_get_sensor(struct wf_sensor
*sr
)
307 if (!try_module_get(sr
->ops
->owner
))
312 EXPORT_SYMBOL_GPL(wf_get_sensor
);
314 void wf_put_sensor(struct wf_sensor
*sr
)
316 struct module
*mod
= sr
->ops
->owner
;
317 kref_put(&sr
->ref
, wf_sensor_release
);
320 EXPORT_SYMBOL_GPL(wf_put_sensor
);
324 * Client & notification
327 int wf_register_client(struct notifier_block
*nb
)
330 struct wf_control
*ct
;
331 struct wf_sensor
*sr
;
333 mutex_lock(&wf_lock
);
334 rc
= notifier_chain_register(&wf_client_list
, nb
);
338 list_for_each_entry(ct
, &wf_controls
, link
)
339 wf_notify(WF_EVENT_NEW_CONTROL
, ct
);
340 list_for_each_entry(sr
, &wf_sensors
, link
)
341 wf_notify(WF_EVENT_NEW_SENSOR
, sr
);
342 if (wf_client_count
== 1)
345 mutex_unlock(&wf_lock
);
348 EXPORT_SYMBOL_GPL(wf_register_client
);
350 int wf_unregister_client(struct notifier_block
*nb
)
352 mutex_lock(&wf_lock
);
353 notifier_chain_unregister(&wf_client_list
, nb
);
355 if (wf_client_count
== 0)
357 mutex_unlock(&wf_lock
);
361 EXPORT_SYMBOL_GPL(wf_unregister_client
);
363 void wf_set_overtemp(void)
365 mutex_lock(&wf_lock
);
367 if (wf_overtemp
== 1) {
368 printk(KERN_WARNING
"windfarm: Overtemp condition detected !\n");
369 wf_overtemp_counter
= 0;
370 wf_notify(WF_EVENT_OVERTEMP
, NULL
);
372 mutex_unlock(&wf_lock
);
374 EXPORT_SYMBOL_GPL(wf_set_overtemp
);
376 void wf_clear_overtemp(void)
378 mutex_lock(&wf_lock
);
379 WARN_ON(wf_overtemp
== 0);
380 if (wf_overtemp
== 0) {
381 mutex_unlock(&wf_lock
);
385 if (wf_overtemp
== 0) {
386 printk(KERN_WARNING
"windfarm: Overtemp condition cleared !\n");
387 wf_notify(WF_EVENT_NORMALTEMP
, NULL
);
389 mutex_unlock(&wf_lock
);
391 EXPORT_SYMBOL_GPL(wf_clear_overtemp
);
393 int wf_is_overtemp(void)
395 return (wf_overtemp
!= 0);
397 EXPORT_SYMBOL_GPL(wf_is_overtemp
);
399 static struct platform_device wf_platform_device
= {
403 static int __init
windfarm_core_init(void)
405 DBG("wf: core loaded\n");
407 platform_device_register(&wf_platform_device
);
411 static void __exit
windfarm_core_exit(void)
413 BUG_ON(wf_client_count
!= 0);
415 DBG("wf: core unloaded\n");
417 platform_device_unregister(&wf_platform_device
);
421 module_init(windfarm_core_init
);
422 module_exit(windfarm_core_exit
);
424 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
425 MODULE_DESCRIPTION("Core component of PowerMac thermal control");
426 MODULE_LICENSE("GPL");