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");
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
.mode
= 0644;
217 new_ct
->attr
.show
= wf_show_control
;
218 new_ct
->attr
.store
= wf_store_control
;
219 if (device_create_file(&wf_platform_device
.dev
, &new_ct
->attr
))
220 printk(KERN_WARNING
"windfarm: device_create_file failed"
221 " for %s\n", new_ct
->name
);
222 /* the subsystem still does useful work without the file */
224 DBG("wf: Registered control %s\n", new_ct
->name
);
226 wf_notify(WF_EVENT_NEW_CONTROL
, new_ct
);
227 mutex_unlock(&wf_lock
);
231 EXPORT_SYMBOL_GPL(wf_register_control
);
233 void wf_unregister_control(struct wf_control
*ct
)
235 mutex_lock(&wf_lock
);
237 mutex_unlock(&wf_lock
);
239 DBG("wf: Unregistered control %s\n", ct
->name
);
241 kref_put(&ct
->ref
, wf_control_release
);
243 EXPORT_SYMBOL_GPL(wf_unregister_control
);
245 struct wf_control
* wf_find_control(const char *name
)
247 struct wf_control
*ct
;
249 mutex_lock(&wf_lock
);
250 list_for_each_entry(ct
, &wf_controls
, link
) {
251 if (!strcmp(ct
->name
, name
)) {
252 if (wf_get_control(ct
))
254 mutex_unlock(&wf_lock
);
258 mutex_unlock(&wf_lock
);
261 EXPORT_SYMBOL_GPL(wf_find_control
);
263 int wf_get_control(struct wf_control
*ct
)
265 if (!try_module_get(ct
->ops
->owner
))
270 EXPORT_SYMBOL_GPL(wf_get_control
);
272 void wf_put_control(struct wf_control
*ct
)
274 struct module
*mod
= ct
->ops
->owner
;
275 kref_put(&ct
->ref
, wf_control_release
);
278 EXPORT_SYMBOL_GPL(wf_put_control
);
286 static void wf_sensor_release(struct kref
*kref
)
288 struct wf_sensor
*sr
= container_of(kref
, struct wf_sensor
, ref
);
290 DBG("wf: Deleting sensor %s\n", sr
->name
);
292 if (sr
->ops
&& sr
->ops
->release
)
293 sr
->ops
->release(sr
);
298 static ssize_t
wf_show_sensor(struct device
*dev
,
299 struct device_attribute
*attr
, char *buf
)
301 struct wf_sensor
*sens
= container_of(attr
, struct wf_sensor
, attr
);
305 err
= sens
->ops
->get_value(sens
, &val
);
308 return sprintf(buf
, "%d.%03d\n", FIX32TOPRINT(val
));
311 int wf_register_sensor(struct wf_sensor
*new_sr
)
313 struct wf_sensor
*sr
;
315 mutex_lock(&wf_lock
);
316 list_for_each_entry(sr
, &wf_sensors
, link
) {
317 if (!strcmp(sr
->name
, new_sr
->name
)) {
318 printk(KERN_WARNING
"windfarm: trying to register"
319 " duplicate sensor %s\n", sr
->name
);
320 mutex_unlock(&wf_lock
);
324 kref_init(&new_sr
->ref
);
325 list_add(&new_sr
->link
, &wf_sensors
);
327 new_sr
->attr
.attr
.name
= new_sr
->name
;
328 new_sr
->attr
.attr
.mode
= 0444;
329 new_sr
->attr
.show
= wf_show_sensor
;
330 new_sr
->attr
.store
= NULL
;
331 if (device_create_file(&wf_platform_device
.dev
, &new_sr
->attr
))
332 printk(KERN_WARNING
"windfarm: device_create_file failed"
333 " for %s\n", new_sr
->name
);
334 /* the subsystem still does useful work without the file */
336 DBG("wf: Registered sensor %s\n", new_sr
->name
);
338 wf_notify(WF_EVENT_NEW_SENSOR
, new_sr
);
339 mutex_unlock(&wf_lock
);
343 EXPORT_SYMBOL_GPL(wf_register_sensor
);
345 void wf_unregister_sensor(struct wf_sensor
*sr
)
347 mutex_lock(&wf_lock
);
349 mutex_unlock(&wf_lock
);
351 DBG("wf: Unregistered sensor %s\n", sr
->name
);
355 EXPORT_SYMBOL_GPL(wf_unregister_sensor
);
357 struct wf_sensor
* wf_find_sensor(const char *name
)
359 struct wf_sensor
*sr
;
361 mutex_lock(&wf_lock
);
362 list_for_each_entry(sr
, &wf_sensors
, link
) {
363 if (!strcmp(sr
->name
, name
)) {
364 if (wf_get_sensor(sr
))
366 mutex_unlock(&wf_lock
);
370 mutex_unlock(&wf_lock
);
373 EXPORT_SYMBOL_GPL(wf_find_sensor
);
375 int wf_get_sensor(struct wf_sensor
*sr
)
377 if (!try_module_get(sr
->ops
->owner
))
382 EXPORT_SYMBOL_GPL(wf_get_sensor
);
384 void wf_put_sensor(struct wf_sensor
*sr
)
386 struct module
*mod
= sr
->ops
->owner
;
387 kref_put(&sr
->ref
, wf_sensor_release
);
390 EXPORT_SYMBOL_GPL(wf_put_sensor
);
394 * Client & notification
397 int wf_register_client(struct notifier_block
*nb
)
400 struct wf_control
*ct
;
401 struct wf_sensor
*sr
;
403 mutex_lock(&wf_lock
);
404 rc
= blocking_notifier_chain_register(&wf_client_list
, nb
);
408 list_for_each_entry(ct
, &wf_controls
, link
)
409 wf_notify(WF_EVENT_NEW_CONTROL
, ct
);
410 list_for_each_entry(sr
, &wf_sensors
, link
)
411 wf_notify(WF_EVENT_NEW_SENSOR
, sr
);
412 if (wf_client_count
== 1)
415 mutex_unlock(&wf_lock
);
418 EXPORT_SYMBOL_GPL(wf_register_client
);
420 int wf_unregister_client(struct notifier_block
*nb
)
422 mutex_lock(&wf_lock
);
423 blocking_notifier_chain_unregister(&wf_client_list
, nb
);
425 if (wf_client_count
== 0)
427 mutex_unlock(&wf_lock
);
431 EXPORT_SYMBOL_GPL(wf_unregister_client
);
433 void wf_set_overtemp(void)
435 mutex_lock(&wf_lock
);
437 if (wf_overtemp
== 1) {
438 printk(KERN_WARNING
"windfarm: Overtemp condition detected !\n");
439 wf_overtemp_counter
= 0;
440 wf_notify(WF_EVENT_OVERTEMP
, NULL
);
442 mutex_unlock(&wf_lock
);
444 EXPORT_SYMBOL_GPL(wf_set_overtemp
);
446 void wf_clear_overtemp(void)
448 mutex_lock(&wf_lock
);
449 WARN_ON(wf_overtemp
== 0);
450 if (wf_overtemp
== 0) {
451 mutex_unlock(&wf_lock
);
455 if (wf_overtemp
== 0) {
456 printk(KERN_WARNING
"windfarm: Overtemp condition cleared !\n");
457 wf_notify(WF_EVENT_NORMALTEMP
, NULL
);
459 mutex_unlock(&wf_lock
);
461 EXPORT_SYMBOL_GPL(wf_clear_overtemp
);
463 int wf_is_overtemp(void)
465 return (wf_overtemp
!= 0);
467 EXPORT_SYMBOL_GPL(wf_is_overtemp
);
469 static int __init
windfarm_core_init(void)
471 DBG("wf: core loaded\n");
473 /* Don't register on old machines that use therm_pm72 for now */
474 if (machine_is_compatible("PowerMac7,2") ||
475 machine_is_compatible("PowerMac7,3") ||
476 machine_is_compatible("RackMac3,1"))
478 platform_device_register(&wf_platform_device
);
482 static void __exit
windfarm_core_exit(void)
484 BUG_ON(wf_client_count
!= 0);
486 DBG("wf: core unloaded\n");
488 platform_device_unregister(&wf_platform_device
);
492 module_init(windfarm_core_init
);
493 module_exit(windfarm_core_exit
);
495 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
496 MODULE_DESCRIPTION("Core component of PowerMac thermal control");
497 MODULE_LICENSE("GPL");