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
.mode
= 0644;
216 new_ct
->attr
.show
= wf_show_control
;
217 new_ct
->attr
.store
= wf_store_control
;
218 if (device_create_file(&wf_platform_device
.dev
, &new_ct
->attr
))
219 printk(KERN_WARNING
"windfarm: device_create_file failed"
220 " for %s\n", new_ct
->name
);
221 /* the subsystem still does useful work without the file */
223 DBG("wf: Registered control %s\n", new_ct
->name
);
225 wf_notify(WF_EVENT_NEW_CONTROL
, new_ct
);
226 mutex_unlock(&wf_lock
);
230 EXPORT_SYMBOL_GPL(wf_register_control
);
232 void wf_unregister_control(struct wf_control
*ct
)
234 mutex_lock(&wf_lock
);
236 mutex_unlock(&wf_lock
);
238 DBG("wf: Unregistered control %s\n", ct
->name
);
240 kref_put(&ct
->ref
, wf_control_release
);
242 EXPORT_SYMBOL_GPL(wf_unregister_control
);
244 struct wf_control
* wf_find_control(const char *name
)
246 struct wf_control
*ct
;
248 mutex_lock(&wf_lock
);
249 list_for_each_entry(ct
, &wf_controls
, link
) {
250 if (!strcmp(ct
->name
, name
)) {
251 if (wf_get_control(ct
))
253 mutex_unlock(&wf_lock
);
257 mutex_unlock(&wf_lock
);
260 EXPORT_SYMBOL_GPL(wf_find_control
);
262 int wf_get_control(struct wf_control
*ct
)
264 if (!try_module_get(ct
->ops
->owner
))
269 EXPORT_SYMBOL_GPL(wf_get_control
);
271 void wf_put_control(struct wf_control
*ct
)
273 struct module
*mod
= ct
->ops
->owner
;
274 kref_put(&ct
->ref
, wf_control_release
);
277 EXPORT_SYMBOL_GPL(wf_put_control
);
285 static void wf_sensor_release(struct kref
*kref
)
287 struct wf_sensor
*sr
= container_of(kref
, struct wf_sensor
, ref
);
289 DBG("wf: Deleting sensor %s\n", sr
->name
);
291 if (sr
->ops
&& sr
->ops
->release
)
292 sr
->ops
->release(sr
);
297 static ssize_t
wf_show_sensor(struct device
*dev
,
298 struct device_attribute
*attr
, char *buf
)
300 struct wf_sensor
*sens
= container_of(attr
, struct wf_sensor
, attr
);
304 err
= sens
->ops
->get_value(sens
, &val
);
307 return sprintf(buf
, "%d.%03d\n", FIX32TOPRINT(val
));
310 int wf_register_sensor(struct wf_sensor
*new_sr
)
312 struct wf_sensor
*sr
;
314 mutex_lock(&wf_lock
);
315 list_for_each_entry(sr
, &wf_sensors
, link
) {
316 if (!strcmp(sr
->name
, new_sr
->name
)) {
317 printk(KERN_WARNING
"windfarm: trying to register"
318 " duplicate sensor %s\n", sr
->name
);
319 mutex_unlock(&wf_lock
);
323 kref_init(&new_sr
->ref
);
324 list_add(&new_sr
->link
, &wf_sensors
);
326 new_sr
->attr
.attr
.name
= new_sr
->name
;
327 new_sr
->attr
.attr
.mode
= 0444;
328 new_sr
->attr
.show
= wf_show_sensor
;
329 new_sr
->attr
.store
= NULL
;
330 if (device_create_file(&wf_platform_device
.dev
, &new_sr
->attr
))
331 printk(KERN_WARNING
"windfarm: device_create_file failed"
332 " for %s\n", new_sr
->name
);
333 /* the subsystem still does useful work without the file */
335 DBG("wf: Registered sensor %s\n", new_sr
->name
);
337 wf_notify(WF_EVENT_NEW_SENSOR
, new_sr
);
338 mutex_unlock(&wf_lock
);
342 EXPORT_SYMBOL_GPL(wf_register_sensor
);
344 void wf_unregister_sensor(struct wf_sensor
*sr
)
346 mutex_lock(&wf_lock
);
348 mutex_unlock(&wf_lock
);
350 DBG("wf: Unregistered sensor %s\n", sr
->name
);
354 EXPORT_SYMBOL_GPL(wf_unregister_sensor
);
356 struct wf_sensor
* wf_find_sensor(const char *name
)
358 struct wf_sensor
*sr
;
360 mutex_lock(&wf_lock
);
361 list_for_each_entry(sr
, &wf_sensors
, link
) {
362 if (!strcmp(sr
->name
, name
)) {
363 if (wf_get_sensor(sr
))
365 mutex_unlock(&wf_lock
);
369 mutex_unlock(&wf_lock
);
372 EXPORT_SYMBOL_GPL(wf_find_sensor
);
374 int wf_get_sensor(struct wf_sensor
*sr
)
376 if (!try_module_get(sr
->ops
->owner
))
381 EXPORT_SYMBOL_GPL(wf_get_sensor
);
383 void wf_put_sensor(struct wf_sensor
*sr
)
385 struct module
*mod
= sr
->ops
->owner
;
386 kref_put(&sr
->ref
, wf_sensor_release
);
389 EXPORT_SYMBOL_GPL(wf_put_sensor
);
393 * Client & notification
396 int wf_register_client(struct notifier_block
*nb
)
399 struct wf_control
*ct
;
400 struct wf_sensor
*sr
;
402 mutex_lock(&wf_lock
);
403 rc
= blocking_notifier_chain_register(&wf_client_list
, nb
);
407 list_for_each_entry(ct
, &wf_controls
, link
)
408 wf_notify(WF_EVENT_NEW_CONTROL
, ct
);
409 list_for_each_entry(sr
, &wf_sensors
, link
)
410 wf_notify(WF_EVENT_NEW_SENSOR
, sr
);
411 if (wf_client_count
== 1)
414 mutex_unlock(&wf_lock
);
417 EXPORT_SYMBOL_GPL(wf_register_client
);
419 int wf_unregister_client(struct notifier_block
*nb
)
421 mutex_lock(&wf_lock
);
422 blocking_notifier_chain_unregister(&wf_client_list
, nb
);
424 if (wf_client_count
== 0)
426 mutex_unlock(&wf_lock
);
430 EXPORT_SYMBOL_GPL(wf_unregister_client
);
432 void wf_set_overtemp(void)
434 mutex_lock(&wf_lock
);
436 if (wf_overtemp
== 1) {
437 printk(KERN_WARNING
"windfarm: Overtemp condition detected !\n");
438 wf_overtemp_counter
= 0;
439 wf_notify(WF_EVENT_OVERTEMP
, NULL
);
441 mutex_unlock(&wf_lock
);
443 EXPORT_SYMBOL_GPL(wf_set_overtemp
);
445 void wf_clear_overtemp(void)
447 mutex_lock(&wf_lock
);
448 WARN_ON(wf_overtemp
== 0);
449 if (wf_overtemp
== 0) {
450 mutex_unlock(&wf_lock
);
454 if (wf_overtemp
== 0) {
455 printk(KERN_WARNING
"windfarm: Overtemp condition cleared !\n");
456 wf_notify(WF_EVENT_NORMALTEMP
, NULL
);
458 mutex_unlock(&wf_lock
);
460 EXPORT_SYMBOL_GPL(wf_clear_overtemp
);
462 int wf_is_overtemp(void)
464 return (wf_overtemp
!= 0);
466 EXPORT_SYMBOL_GPL(wf_is_overtemp
);
468 static int __init
windfarm_core_init(void)
470 DBG("wf: core loaded\n");
472 /* Don't register on old machines that use therm_pm72 for now */
473 if (machine_is_compatible("PowerMac7,2") ||
474 machine_is_compatible("PowerMac7,3") ||
475 machine_is_compatible("RackMac3,1"))
477 platform_device_register(&wf_platform_device
);
481 static void __exit
windfarm_core_exit(void)
483 BUG_ON(wf_client_count
!= 0);
485 DBG("wf: core unloaded\n");
487 platform_device_unregister(&wf_platform_device
);
491 module_init(windfarm_core_init
);
492 module_exit(windfarm_core_exit
);
494 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
495 MODULE_DESCRIPTION("Core component of PowerMac thermal control");
496 MODULE_LICENSE("GPL");