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");