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>
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
, argv
, envp
, 0);
86 EXPORT_SYMBOL_GPL(wf_critical_overtemp
);
88 static int wf_thread_func(void *data
)
90 unsigned long next
, delay
;
94 DBG("wf: thread started\n");
96 while(!kthread_should_stop()) {
99 if (time_after_eq(jiffies
, next
)) {
100 wf_notify(WF_EVENT_TICK
, NULL
);
102 wf_overtemp_counter
++;
103 /* 10 seconds overtemp, notify userland */
104 if (wf_overtemp_counter
> 10)
105 wf_critical_overtemp();
106 /* 30 seconds, shutdown */
107 if (wf_overtemp_counter
> 30) {
108 printk(KERN_ERR
"windfarm: Overtemp "
110 " seconds, shutting down\n");
117 delay
= next
- jiffies
;
119 schedule_timeout_interruptible(delay
);
121 /* there should be no signal, but oh well */
122 if (signal_pending(current
)) {
123 printk(KERN_WARNING
"windfarm: thread got sigl !\n");
128 DBG("wf: thread stopped\n");
133 static void wf_start_thread(void)
135 wf_thread
= kthread_run(wf_thread_func
, NULL
, "kwindfarm");
136 if (IS_ERR(wf_thread
)) {
137 printk(KERN_ERR
"windfarm: failed to create thread,err %ld\n",
144 static void wf_stop_thread(void)
147 kthread_stop(wf_thread
);
155 static void wf_control_release(struct kref
*kref
)
157 struct wf_control
*ct
= container_of(kref
, struct wf_control
, ref
);
159 DBG("wf: Deleting control %s\n", ct
->name
);
161 if (ct
->ops
&& ct
->ops
->release
)
162 ct
->ops
->release(ct
);
167 static ssize_t
wf_show_control(struct device
*dev
,
168 struct device_attribute
*attr
, char *buf
)
170 struct wf_control
*ctrl
= container_of(attr
, struct wf_control
, attr
);
174 err
= ctrl
->ops
->get_value(ctrl
, &val
);
177 return sprintf(buf
, "%d\n", val
);
180 /* This is really only for debugging... */
181 static ssize_t
wf_store_control(struct device
*dev
,
182 struct device_attribute
*attr
,
183 const char *buf
, size_t count
)
185 struct wf_control
*ctrl
= container_of(attr
, struct wf_control
, attr
);
190 val
= simple_strtoul(buf
, &endp
, 0);
191 while (endp
< buf
+ count
&& (*endp
== ' ' || *endp
== '\n'))
193 if (endp
- buf
< count
)
195 err
= ctrl
->ops
->set_value(ctrl
, val
);
201 int wf_register_control(struct wf_control
*new_ct
)
203 struct wf_control
*ct
;
205 mutex_lock(&wf_lock
);
206 list_for_each_entry(ct
, &wf_controls
, link
) {
207 if (!strcmp(ct
->name
, new_ct
->name
)) {
208 printk(KERN_WARNING
"windfarm: trying to register"
209 " duplicate control %s\n", ct
->name
);
210 mutex_unlock(&wf_lock
);
214 kref_init(&new_ct
->ref
);
215 list_add(&new_ct
->link
, &wf_controls
);
217 new_ct
->attr
.attr
.name
= new_ct
->name
;
218 new_ct
->attr
.attr
.owner
= THIS_MODULE
;
219 new_ct
->attr
.attr
.mode
= 0644;
220 new_ct
->attr
.show
= wf_show_control
;
221 new_ct
->attr
.store
= wf_store_control
;
222 device_create_file(&wf_platform_device
.dev
, &new_ct
->attr
);
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
.owner
= THIS_MODULE
;
329 new_sr
->attr
.attr
.mode
= 0444;
330 new_sr
->attr
.show
= wf_show_sensor
;
331 new_sr
->attr
.store
= NULL
;
332 device_create_file(&wf_platform_device
.dev
, &new_sr
->attr
);
334 DBG("wf: Registered sensor %s\n", new_sr
->name
);
336 wf_notify(WF_EVENT_NEW_SENSOR
, new_sr
);
337 mutex_unlock(&wf_lock
);
341 EXPORT_SYMBOL_GPL(wf_register_sensor
);
343 void wf_unregister_sensor(struct wf_sensor
*sr
)
345 mutex_lock(&wf_lock
);
347 mutex_unlock(&wf_lock
);
349 DBG("wf: Unregistered sensor %s\n", sr
->name
);
353 EXPORT_SYMBOL_GPL(wf_unregister_sensor
);
355 struct wf_sensor
* wf_find_sensor(const char *name
)
357 struct wf_sensor
*sr
;
359 mutex_lock(&wf_lock
);
360 list_for_each_entry(sr
, &wf_sensors
, link
) {
361 if (!strcmp(sr
->name
, name
)) {
362 if (wf_get_sensor(sr
))
364 mutex_unlock(&wf_lock
);
368 mutex_unlock(&wf_lock
);
371 EXPORT_SYMBOL_GPL(wf_find_sensor
);
373 int wf_get_sensor(struct wf_sensor
*sr
)
375 if (!try_module_get(sr
->ops
->owner
))
380 EXPORT_SYMBOL_GPL(wf_get_sensor
);
382 void wf_put_sensor(struct wf_sensor
*sr
)
384 struct module
*mod
= sr
->ops
->owner
;
385 kref_put(&sr
->ref
, wf_sensor_release
);
388 EXPORT_SYMBOL_GPL(wf_put_sensor
);
392 * Client & notification
395 int wf_register_client(struct notifier_block
*nb
)
398 struct wf_control
*ct
;
399 struct wf_sensor
*sr
;
401 mutex_lock(&wf_lock
);
402 rc
= blocking_notifier_chain_register(&wf_client_list
, nb
);
406 list_for_each_entry(ct
, &wf_controls
, link
)
407 wf_notify(WF_EVENT_NEW_CONTROL
, ct
);
408 list_for_each_entry(sr
, &wf_sensors
, link
)
409 wf_notify(WF_EVENT_NEW_SENSOR
, sr
);
410 if (wf_client_count
== 1)
413 mutex_unlock(&wf_lock
);
416 EXPORT_SYMBOL_GPL(wf_register_client
);
418 int wf_unregister_client(struct notifier_block
*nb
)
420 mutex_lock(&wf_lock
);
421 blocking_notifier_chain_unregister(&wf_client_list
, nb
);
423 if (wf_client_count
== 0)
425 mutex_unlock(&wf_lock
);
429 EXPORT_SYMBOL_GPL(wf_unregister_client
);
431 void wf_set_overtemp(void)
433 mutex_lock(&wf_lock
);
435 if (wf_overtemp
== 1) {
436 printk(KERN_WARNING
"windfarm: Overtemp condition detected !\n");
437 wf_overtemp_counter
= 0;
438 wf_notify(WF_EVENT_OVERTEMP
, NULL
);
440 mutex_unlock(&wf_lock
);
442 EXPORT_SYMBOL_GPL(wf_set_overtemp
);
444 void wf_clear_overtemp(void)
446 mutex_lock(&wf_lock
);
447 WARN_ON(wf_overtemp
== 0);
448 if (wf_overtemp
== 0) {
449 mutex_unlock(&wf_lock
);
453 if (wf_overtemp
== 0) {
454 printk(KERN_WARNING
"windfarm: Overtemp condition cleared !\n");
455 wf_notify(WF_EVENT_NORMALTEMP
, NULL
);
457 mutex_unlock(&wf_lock
);
459 EXPORT_SYMBOL_GPL(wf_clear_overtemp
);
461 int wf_is_overtemp(void)
463 return (wf_overtemp
!= 0);
465 EXPORT_SYMBOL_GPL(wf_is_overtemp
);
467 static int __init
windfarm_core_init(void)
469 DBG("wf: core loaded\n");
471 /* Don't register on old machines that use therm_pm72 for now */
472 if (machine_is_compatible("PowerMac7,2") ||
473 machine_is_compatible("PowerMac7,3") ||
474 machine_is_compatible("RackMac3,1"))
476 platform_device_register(&wf_platform_device
);
480 static void __exit
windfarm_core_exit(void)
482 BUG_ON(wf_client_count
!= 0);
484 DBG("wf: core unloaded\n");
486 platform_device_unregister(&wf_platform_device
);
490 module_init(windfarm_core_init
);
491 module_exit(windfarm_core_exit
);
493 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
494 MODULE_DESCRIPTION("Core component of PowerMac thermal control");
495 MODULE_LICENSE("GPL");