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/kthread.h>
31 #include <linux/jiffies.h>
32 #include <linux/reboot.h>
33 #include <linux/device.h>
34 #include <linux/platform_device.h>
35 #include <linux/mutex.h>
36 #include <linux/freezer.h>
47 #define DBG(args...) printk(args)
49 #define DBG(args...) do { } while(0)
52 static LIST_HEAD(wf_controls
);
53 static LIST_HEAD(wf_sensors
);
54 static DEFINE_MUTEX(wf_lock
);
55 static BLOCKING_NOTIFIER_HEAD(wf_client_list
);
56 static int wf_client_count
;
57 static unsigned int wf_overtemp
;
58 static unsigned int wf_overtemp_counter
;
59 struct task_struct
*wf_thread
;
61 static struct platform_device wf_platform_device
= {
66 * Utilities & tick thread
69 static inline void wf_notify(int event
, void *param
)
71 blocking_notifier_call_chain(&wf_client_list
, event
, param
);
74 int wf_critical_overtemp(void)
76 static char * critical_overtemp_path
= "/sbin/critical_overtemp";
77 char *argv
[] = { critical_overtemp_path
, NULL
};
78 static char *envp
[] = { "HOME=/",
80 "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
83 return call_usermodehelper(critical_overtemp_path
, argv
, envp
, 0);
85 EXPORT_SYMBOL_GPL(wf_critical_overtemp
);
87 static int wf_thread_func(void *data
)
89 unsigned long next
, delay
;
93 DBG("wf: thread started\n");
95 while(!kthread_should_stop()) {
96 if (time_after_eq(jiffies
, next
)) {
97 wf_notify(WF_EVENT_TICK
, NULL
);
99 wf_overtemp_counter
++;
100 /* 10 seconds overtemp, notify userland */
101 if (wf_overtemp_counter
> 10)
102 wf_critical_overtemp();
103 /* 30 seconds, shutdown */
104 if (wf_overtemp_counter
> 30) {
105 printk(KERN_ERR
"windfarm: Overtemp "
107 " seconds, shutting down\n");
114 delay
= next
- jiffies
;
116 schedule_timeout_interruptible(delay
);
118 /* there should be no non-suspend signal, but oh well */
119 if (signal_pending(current
) && !try_to_freeze()) {
120 printk(KERN_WARNING
"windfarm: thread got sigl !\n");
125 DBG("wf: thread stopped\n");
130 static void wf_start_thread(void)
132 wf_thread
= kthread_run(wf_thread_func
, NULL
, "kwindfarm");
133 if (IS_ERR(wf_thread
)) {
134 printk(KERN_ERR
"windfarm: failed to create thread,err %ld\n",
141 static void wf_stop_thread(void)
144 kthread_stop(wf_thread
);
152 static void wf_control_release(struct kref
*kref
)
154 struct wf_control
*ct
= container_of(kref
, struct wf_control
, ref
);
156 DBG("wf: Deleting control %s\n", ct
->name
);
158 if (ct
->ops
&& ct
->ops
->release
)
159 ct
->ops
->release(ct
);
164 static ssize_t
wf_show_control(struct device
*dev
,
165 struct device_attribute
*attr
, char *buf
)
167 struct wf_control
*ctrl
= container_of(attr
, struct wf_control
, attr
);
171 err
= ctrl
->ops
->get_value(ctrl
, &val
);
174 return sprintf(buf
, "%d\n", val
);
177 /* This is really only for debugging... */
178 static ssize_t
wf_store_control(struct device
*dev
,
179 struct device_attribute
*attr
,
180 const char *buf
, size_t count
)
182 struct wf_control
*ctrl
= container_of(attr
, struct wf_control
, attr
);
187 val
= simple_strtoul(buf
, &endp
, 0);
188 while (endp
< buf
+ count
&& (*endp
== ' ' || *endp
== '\n'))
190 if (endp
- buf
< count
)
192 err
= ctrl
->ops
->set_value(ctrl
, val
);
198 int wf_register_control(struct wf_control
*new_ct
)
200 struct wf_control
*ct
;
202 mutex_lock(&wf_lock
);
203 list_for_each_entry(ct
, &wf_controls
, link
) {
204 if (!strcmp(ct
->name
, new_ct
->name
)) {
205 printk(KERN_WARNING
"windfarm: trying to register"
206 " duplicate control %s\n", ct
->name
);
207 mutex_unlock(&wf_lock
);
211 kref_init(&new_ct
->ref
);
212 list_add(&new_ct
->link
, &wf_controls
);
214 new_ct
->attr
.attr
.name
= new_ct
->name
;
215 new_ct
->attr
.attr
.owner
= THIS_MODULE
;
216 new_ct
->attr
.attr
.mode
= 0644;
217 new_ct
->attr
.show
= wf_show_control
;
218 new_ct
->attr
.store
= wf_store_control
;
219 device_create_file(&wf_platform_device
.dev
, &new_ct
->attr
);
221 DBG("wf: Registered control %s\n", new_ct
->name
);
223 wf_notify(WF_EVENT_NEW_CONTROL
, new_ct
);
224 mutex_unlock(&wf_lock
);
228 EXPORT_SYMBOL_GPL(wf_register_control
);
230 void wf_unregister_control(struct wf_control
*ct
)
232 mutex_lock(&wf_lock
);
234 mutex_unlock(&wf_lock
);
236 DBG("wf: Unregistered control %s\n", ct
->name
);
238 kref_put(&ct
->ref
, wf_control_release
);
240 EXPORT_SYMBOL_GPL(wf_unregister_control
);
242 struct wf_control
* wf_find_control(const char *name
)
244 struct wf_control
*ct
;
246 mutex_lock(&wf_lock
);
247 list_for_each_entry(ct
, &wf_controls
, link
) {
248 if (!strcmp(ct
->name
, name
)) {
249 if (wf_get_control(ct
))
251 mutex_unlock(&wf_lock
);
255 mutex_unlock(&wf_lock
);
258 EXPORT_SYMBOL_GPL(wf_find_control
);
260 int wf_get_control(struct wf_control
*ct
)
262 if (!try_module_get(ct
->ops
->owner
))
267 EXPORT_SYMBOL_GPL(wf_get_control
);
269 void wf_put_control(struct wf_control
*ct
)
271 struct module
*mod
= ct
->ops
->owner
;
272 kref_put(&ct
->ref
, wf_control_release
);
275 EXPORT_SYMBOL_GPL(wf_put_control
);
283 static void wf_sensor_release(struct kref
*kref
)
285 struct wf_sensor
*sr
= container_of(kref
, struct wf_sensor
, ref
);
287 DBG("wf: Deleting sensor %s\n", sr
->name
);
289 if (sr
->ops
&& sr
->ops
->release
)
290 sr
->ops
->release(sr
);
295 static ssize_t
wf_show_sensor(struct device
*dev
,
296 struct device_attribute
*attr
, char *buf
)
298 struct wf_sensor
*sens
= container_of(attr
, struct wf_sensor
, attr
);
302 err
= sens
->ops
->get_value(sens
, &val
);
305 return sprintf(buf
, "%d.%03d\n", FIX32TOPRINT(val
));
308 int wf_register_sensor(struct wf_sensor
*new_sr
)
310 struct wf_sensor
*sr
;
312 mutex_lock(&wf_lock
);
313 list_for_each_entry(sr
, &wf_sensors
, link
) {
314 if (!strcmp(sr
->name
, new_sr
->name
)) {
315 printk(KERN_WARNING
"windfarm: trying to register"
316 " duplicate sensor %s\n", sr
->name
);
317 mutex_unlock(&wf_lock
);
321 kref_init(&new_sr
->ref
);
322 list_add(&new_sr
->link
, &wf_sensors
);
324 new_sr
->attr
.attr
.name
= new_sr
->name
;
325 new_sr
->attr
.attr
.owner
= THIS_MODULE
;
326 new_sr
->attr
.attr
.mode
= 0444;
327 new_sr
->attr
.show
= wf_show_sensor
;
328 new_sr
->attr
.store
= NULL
;
329 device_create_file(&wf_platform_device
.dev
, &new_sr
->attr
);
331 DBG("wf: Registered sensor %s\n", new_sr
->name
);
333 wf_notify(WF_EVENT_NEW_SENSOR
, new_sr
);
334 mutex_unlock(&wf_lock
);
338 EXPORT_SYMBOL_GPL(wf_register_sensor
);
340 void wf_unregister_sensor(struct wf_sensor
*sr
)
342 mutex_lock(&wf_lock
);
344 mutex_unlock(&wf_lock
);
346 DBG("wf: Unregistered sensor %s\n", sr
->name
);
350 EXPORT_SYMBOL_GPL(wf_unregister_sensor
);
352 struct wf_sensor
* wf_find_sensor(const char *name
)
354 struct wf_sensor
*sr
;
356 mutex_lock(&wf_lock
);
357 list_for_each_entry(sr
, &wf_sensors
, link
) {
358 if (!strcmp(sr
->name
, name
)) {
359 if (wf_get_sensor(sr
))
361 mutex_unlock(&wf_lock
);
365 mutex_unlock(&wf_lock
);
368 EXPORT_SYMBOL_GPL(wf_find_sensor
);
370 int wf_get_sensor(struct wf_sensor
*sr
)
372 if (!try_module_get(sr
->ops
->owner
))
377 EXPORT_SYMBOL_GPL(wf_get_sensor
);
379 void wf_put_sensor(struct wf_sensor
*sr
)
381 struct module
*mod
= sr
->ops
->owner
;
382 kref_put(&sr
->ref
, wf_sensor_release
);
385 EXPORT_SYMBOL_GPL(wf_put_sensor
);
389 * Client & notification
392 int wf_register_client(struct notifier_block
*nb
)
395 struct wf_control
*ct
;
396 struct wf_sensor
*sr
;
398 mutex_lock(&wf_lock
);
399 rc
= blocking_notifier_chain_register(&wf_client_list
, nb
);
403 list_for_each_entry(ct
, &wf_controls
, link
)
404 wf_notify(WF_EVENT_NEW_CONTROL
, ct
);
405 list_for_each_entry(sr
, &wf_sensors
, link
)
406 wf_notify(WF_EVENT_NEW_SENSOR
, sr
);
407 if (wf_client_count
== 1)
410 mutex_unlock(&wf_lock
);
413 EXPORT_SYMBOL_GPL(wf_register_client
);
415 int wf_unregister_client(struct notifier_block
*nb
)
417 mutex_lock(&wf_lock
);
418 blocking_notifier_chain_unregister(&wf_client_list
, nb
);
420 if (wf_client_count
== 0)
422 mutex_unlock(&wf_lock
);
426 EXPORT_SYMBOL_GPL(wf_unregister_client
);
428 void wf_set_overtemp(void)
430 mutex_lock(&wf_lock
);
432 if (wf_overtemp
== 1) {
433 printk(KERN_WARNING
"windfarm: Overtemp condition detected !\n");
434 wf_overtemp_counter
= 0;
435 wf_notify(WF_EVENT_OVERTEMP
, NULL
);
437 mutex_unlock(&wf_lock
);
439 EXPORT_SYMBOL_GPL(wf_set_overtemp
);
441 void wf_clear_overtemp(void)
443 mutex_lock(&wf_lock
);
444 WARN_ON(wf_overtemp
== 0);
445 if (wf_overtemp
== 0) {
446 mutex_unlock(&wf_lock
);
450 if (wf_overtemp
== 0) {
451 printk(KERN_WARNING
"windfarm: Overtemp condition cleared !\n");
452 wf_notify(WF_EVENT_NORMALTEMP
, NULL
);
454 mutex_unlock(&wf_lock
);
456 EXPORT_SYMBOL_GPL(wf_clear_overtemp
);
458 int wf_is_overtemp(void)
460 return (wf_overtemp
!= 0);
462 EXPORT_SYMBOL_GPL(wf_is_overtemp
);
464 static int __init
windfarm_core_init(void)
466 DBG("wf: core loaded\n");
468 /* Don't register on old machines that use therm_pm72 for now */
469 if (machine_is_compatible("PowerMac7,2") ||
470 machine_is_compatible("PowerMac7,3") ||
471 machine_is_compatible("RackMac3,1"))
473 platform_device_register(&wf_platform_device
);
477 static void __exit
windfarm_core_exit(void)
479 BUG_ON(wf_client_count
!= 0);
481 DBG("wf: core unloaded\n");
483 platform_device_unregister(&wf_platform_device
);
487 module_init(windfarm_core_init
);
488 module_exit(windfarm_core_exit
);
490 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
491 MODULE_DESCRIPTION("Core component of PowerMac thermal control");
492 MODULE_LICENSE("GPL");