of: MSI: Simplify irqdomain lookup
[linux/fpc-iii.git] / drivers / macintosh / windfarm_core.c
blob465d770ab0bb09a96e8603a503425bc12ee5a101
1 /*
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.
12 * TODO:
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>
39 #include <asm/prom.h>
41 #include "windfarm.h"
43 #define VERSION "0.2"
45 #undef DEBUG
47 #ifdef DEBUG
48 #define DBG(args...) printk(args)
49 #else
50 #define DBG(args...) do { } while(0)
51 #endif
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 = {
63 .name = "windfarm",
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=/",
80 "TERM=linux",
81 "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
82 NULL };
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;
92 next = jiffies;
94 DBG("wf: thread started\n");
96 set_freezable();
97 while (!kthread_should_stop()) {
98 try_to_freeze();
100 if (time_after_eq(jiffies, next)) {
101 wf_notify(WF_EVENT_TICK, NULL);
102 if (wf_overtemp) {
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 "
110 "for more than 30"
111 " seconds, shutting down\n");
112 machine_power_off();
115 next += HZ;
118 delay = next - jiffies;
119 if (delay <= HZ)
120 schedule_timeout_interruptible(delay);
123 DBG("wf: thread stopped\n");
125 return 0;
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",
133 PTR_ERR(wf_thread));
134 wf_thread = NULL;
139 static void wf_stop_thread(void)
141 if (wf_thread)
142 kthread_stop(wf_thread);
143 wf_thread = NULL;
147 * Controls
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);
158 else
159 kfree(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);
166 const char *typestr;
167 s32 val = 0;
168 int err;
170 err = ctrl->ops->get_value(ctrl, &val);
171 if (err < 0) {
172 if (err == -EFAULT)
173 return sprintf(buf, "<HW FAULT>\n");
174 return err;
176 switch(ctrl->type) {
177 case WF_CONTROL_RPM_FAN:
178 typestr = " RPM";
179 break;
180 case WF_CONTROL_PWM_FAN:
181 typestr = " %";
182 break;
183 default:
184 typestr = "";
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);
195 int val;
196 int err;
197 char *endp;
199 val = simple_strtoul(buf, &endp, 0);
200 while (endp < buf + count && (*endp == ' ' || *endp == '\n'))
201 ++endp;
202 if (endp - buf < count)
203 return -EINVAL;
204 err = ctrl->ops->set_value(ctrl, val);
205 if (err < 0)
206 return err;
207 return count;
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);
220 return -EEXIST;
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);
241 return 0;
243 EXPORT_SYMBOL_GPL(wf_register_control);
245 void wf_unregister_control(struct wf_control *ct)
247 mutex_lock(&wf_lock);
248 list_del(&ct->link);
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 int wf_get_control(struct wf_control *ct)
259 if (!try_module_get(ct->ops->owner))
260 return -ENODEV;
261 kref_get(&ct->ref);
262 return 0;
264 EXPORT_SYMBOL_GPL(wf_get_control);
266 void wf_put_control(struct wf_control *ct)
268 struct module *mod = ct->ops->owner;
269 kref_put(&ct->ref, wf_control_release);
270 module_put(mod);
272 EXPORT_SYMBOL_GPL(wf_put_control);
276 * Sensors
280 static void wf_sensor_release(struct kref *kref)
282 struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref);
284 DBG("wf: Deleting sensor %s\n", sr->name);
286 if (sr->ops && sr->ops->release)
287 sr->ops->release(sr);
288 else
289 kfree(sr);
292 static ssize_t wf_show_sensor(struct device *dev,
293 struct device_attribute *attr, char *buf)
295 struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr);
296 s32 val = 0;
297 int err;
299 err = sens->ops->get_value(sens, &val);
300 if (err < 0)
301 return err;
302 return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val));
305 int wf_register_sensor(struct wf_sensor *new_sr)
307 struct wf_sensor *sr;
309 mutex_lock(&wf_lock);
310 list_for_each_entry(sr, &wf_sensors, link) {
311 if (!strcmp(sr->name, new_sr->name)) {
312 printk(KERN_WARNING "windfarm: trying to register"
313 " duplicate sensor %s\n", sr->name);
314 mutex_unlock(&wf_lock);
315 return -EEXIST;
318 kref_init(&new_sr->ref);
319 list_add(&new_sr->link, &wf_sensors);
321 sysfs_attr_init(&new_sr->attr.attr);
322 new_sr->attr.attr.name = new_sr->name;
323 new_sr->attr.attr.mode = 0444;
324 new_sr->attr.show = wf_show_sensor;
325 new_sr->attr.store = NULL;
326 if (device_create_file(&wf_platform_device.dev, &new_sr->attr))
327 printk(KERN_WARNING "windfarm: device_create_file failed"
328 " for %s\n", new_sr->name);
329 /* the subsystem still does useful work without the file */
331 DBG("wf: Registered sensor %s\n", new_sr->name);
333 wf_notify(WF_EVENT_NEW_SENSOR, new_sr);
334 mutex_unlock(&wf_lock);
336 return 0;
338 EXPORT_SYMBOL_GPL(wf_register_sensor);
340 void wf_unregister_sensor(struct wf_sensor *sr)
342 mutex_lock(&wf_lock);
343 list_del(&sr->link);
344 mutex_unlock(&wf_lock);
346 DBG("wf: Unregistered sensor %s\n", sr->name);
348 wf_put_sensor(sr);
350 EXPORT_SYMBOL_GPL(wf_unregister_sensor);
352 int wf_get_sensor(struct wf_sensor *sr)
354 if (!try_module_get(sr->ops->owner))
355 return -ENODEV;
356 kref_get(&sr->ref);
357 return 0;
359 EXPORT_SYMBOL_GPL(wf_get_sensor);
361 void wf_put_sensor(struct wf_sensor *sr)
363 struct module *mod = sr->ops->owner;
364 kref_put(&sr->ref, wf_sensor_release);
365 module_put(mod);
367 EXPORT_SYMBOL_GPL(wf_put_sensor);
371 * Client & notification
374 int wf_register_client(struct notifier_block *nb)
376 int rc;
377 struct wf_control *ct;
378 struct wf_sensor *sr;
380 mutex_lock(&wf_lock);
381 rc = blocking_notifier_chain_register(&wf_client_list, nb);
382 if (rc != 0)
383 goto bail;
384 wf_client_count++;
385 list_for_each_entry(ct, &wf_controls, link)
386 wf_notify(WF_EVENT_NEW_CONTROL, ct);
387 list_for_each_entry(sr, &wf_sensors, link)
388 wf_notify(WF_EVENT_NEW_SENSOR, sr);
389 if (wf_client_count == 1)
390 wf_start_thread();
391 bail:
392 mutex_unlock(&wf_lock);
393 return rc;
395 EXPORT_SYMBOL_GPL(wf_register_client);
397 int wf_unregister_client(struct notifier_block *nb)
399 mutex_lock(&wf_lock);
400 blocking_notifier_chain_unregister(&wf_client_list, nb);
401 wf_client_count--;
402 if (wf_client_count == 0)
403 wf_stop_thread();
404 mutex_unlock(&wf_lock);
406 return 0;
408 EXPORT_SYMBOL_GPL(wf_unregister_client);
410 void wf_set_overtemp(void)
412 mutex_lock(&wf_lock);
413 wf_overtemp++;
414 if (wf_overtemp == 1) {
415 printk(KERN_WARNING "windfarm: Overtemp condition detected !\n");
416 wf_overtemp_counter = 0;
417 wf_notify(WF_EVENT_OVERTEMP, NULL);
419 mutex_unlock(&wf_lock);
421 EXPORT_SYMBOL_GPL(wf_set_overtemp);
423 void wf_clear_overtemp(void)
425 mutex_lock(&wf_lock);
426 WARN_ON(wf_overtemp == 0);
427 if (wf_overtemp == 0) {
428 mutex_unlock(&wf_lock);
429 return;
431 wf_overtemp--;
432 if (wf_overtemp == 0) {
433 printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n");
434 wf_notify(WF_EVENT_NORMALTEMP, NULL);
436 mutex_unlock(&wf_lock);
438 EXPORT_SYMBOL_GPL(wf_clear_overtemp);
440 static int __init windfarm_core_init(void)
442 DBG("wf: core loaded\n");
444 platform_device_register(&wf_platform_device);
445 return 0;
448 static void __exit windfarm_core_exit(void)
450 BUG_ON(wf_client_count != 0);
452 DBG("wf: core unloaded\n");
454 platform_device_unregister(&wf_platform_device);
458 module_init(windfarm_core_init);
459 module_exit(windfarm_core_exit);
461 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
462 MODULE_DESCRIPTION("Core component of PowerMac thermal control");
463 MODULE_LICENSE("GPL");