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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/arm/kernel/apm.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/arm/kernel/apm.c')
-rw-r--r--arch/arm/kernel/apm.c610
1 files changed, 610 insertions, 0 deletions
diff --git a/arch/arm/kernel/apm.c b/arch/arm/kernel/apm.c
new file mode 100644
index 000000000000..b0bbd1e62ebb
--- /dev/null
+++ b/arch/arm/kernel/apm.c
@@ -0,0 +1,610 @@
1/*
2 * bios-less APM driver for ARM Linux
3 * Jamey Hicks <jamey@crl.dec.com>
4 * adapted from the APM BIOS driver for Linux by Stephen Rothwell (sfr@linuxcare.com)
5 *
6 * APM 1.2 Reference:
7 * Intel Corporation, Microsoft Corporation. Advanced Power Management
8 * (APM) BIOS Interface Specification, Revision 1.2, February 1996.
9 *
10 * [This document is available from Microsoft at:
11 * http://www.microsoft.com/hwdev/busbios/amp_12.htm]
12 */
13#include <linux/config.h>
14#include <linux/module.h>
15#include <linux/poll.h>
16#include <linux/timer.h>
17#include <linux/slab.h>
18#include <linux/proc_fs.h>
19#include <linux/miscdevice.h>
20#include <linux/apm_bios.h>
21#include <linux/sched.h>
22#include <linux/pm.h>
23#include <linux/device.h>
24#include <linux/kernel.h>
25#include <linux/list.h>
26#include <linux/init.h>
27#include <linux/completion.h>
28
29#include <asm/apm.h> /* apm_power_info */
30#include <asm/system.h>
31
32/*
33 * The apm_bios device is one of the misc char devices.
34 * This is its minor number.
35 */
36#define APM_MINOR_DEV 134
37
38/*
39 * See Documentation/Config.help for the configuration options.
40 *
41 * Various options can be changed at boot time as follows:
42 * (We allow underscores for compatibility with the modules code)
43 * apm=on/off enable/disable APM
44 */
45
46/*
47 * Maximum number of events stored
48 */
49#define APM_MAX_EVENTS 16
50
51struct apm_queue {
52 unsigned int event_head;
53 unsigned int event_tail;
54 apm_event_t events[APM_MAX_EVENTS];
55};
56
57/*
58 * The per-file APM data
59 */
60struct apm_user {
61 struct list_head list;
62
63 unsigned int suser: 1;
64 unsigned int writer: 1;
65 unsigned int reader: 1;
66
67 int suspend_result;
68 unsigned int suspend_state;
69#define SUSPEND_NONE 0 /* no suspend pending */
70#define SUSPEND_PENDING 1 /* suspend pending read */
71#define SUSPEND_READ 2 /* suspend read, pending ack */
72#define SUSPEND_ACKED 3 /* suspend acked */
73#define SUSPEND_DONE 4 /* suspend completed */
74
75 struct apm_queue queue;
76};
77
78/*
79 * Local variables
80 */
81static int suspends_pending;
82static int apm_disabled;
83
84static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
85static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
86
87/*
88 * This is a list of everyone who has opened /dev/apm_bios
89 */
90static DECLARE_RWSEM(user_list_lock);
91static LIST_HEAD(apm_user_list);
92
93/*
94 * kapmd info. kapmd provides us a process context to handle
95 * "APM" events within - specifically necessary if we're going
96 * to be suspending the system.
97 */
98static DECLARE_WAIT_QUEUE_HEAD(kapmd_wait);
99static DECLARE_COMPLETION(kapmd_exit);
100static DEFINE_SPINLOCK(kapmd_queue_lock);
101static struct apm_queue kapmd_queue;
102
103
104static const char driver_version[] = "1.13"; /* no spaces */
105
106
107
108/*
109 * Compatibility cruft until the IPAQ people move over to the new
110 * interface.
111 */
112static void __apm_get_power_status(struct apm_power_info *info)
113{
114}
115
116/*
117 * This allows machines to provide their own "apm get power status" function.
118 */
119void (*apm_get_power_status)(struct apm_power_info *) = __apm_get_power_status;
120EXPORT_SYMBOL(apm_get_power_status);
121
122
123/*
124 * APM event queue management.
125 */
126static inline int queue_empty(struct apm_queue *q)
127{
128 return q->event_head == q->event_tail;
129}
130
131static inline apm_event_t queue_get_event(struct apm_queue *q)
132{
133 q->event_tail = (q->event_tail + 1) % APM_MAX_EVENTS;
134 return q->events[q->event_tail];
135}
136
137static void queue_add_event(struct apm_queue *q, apm_event_t event)
138{
139 q->event_head = (q->event_head + 1) % APM_MAX_EVENTS;
140 if (q->event_head == q->event_tail) {
141 static int notified;
142
143 if (notified++ == 0)
144 printk(KERN_ERR "apm: an event queue overflowed\n");
145 q->event_tail = (q->event_tail + 1) % APM_MAX_EVENTS;
146 }
147 q->events[q->event_head] = event;
148}
149
150static void queue_event_one_user(struct apm_user *as, apm_event_t event)
151{
152 if (as->suser && as->writer) {
153 switch (event) {
154 case APM_SYS_SUSPEND:
155 case APM_USER_SUSPEND:
156 /*
157 * If this user already has a suspend pending,
158 * don't queue another one.
159 */
160 if (as->suspend_state != SUSPEND_NONE)
161 return;
162
163 as->suspend_state = SUSPEND_PENDING;
164 suspends_pending++;
165 break;
166 }
167 }
168 queue_add_event(&as->queue, event);
169}
170
171static void queue_event(apm_event_t event, struct apm_user *sender)
172{
173 struct apm_user *as;
174
175 down_read(&user_list_lock);
176 list_for_each_entry(as, &apm_user_list, list) {
177 if (as != sender && as->reader)
178 queue_event_one_user(as, event);
179 }
180 up_read(&user_list_lock);
181 wake_up_interruptible(&apm_waitqueue);
182}
183
184static void apm_suspend(void)
185{
186 struct apm_user *as;
187 int err = pm_suspend(PM_SUSPEND_MEM);
188
189 /*
190 * Anyone on the APM queues will think we're still suspended.
191 * Send a message so everyone knows we're now awake again.
192 */
193 queue_event(APM_NORMAL_RESUME, NULL);
194
195 /*
196 * Finally, wake up anyone who is sleeping on the suspend.
197 */
198 down_read(&user_list_lock);
199 list_for_each_entry(as, &apm_user_list, list) {
200 as->suspend_result = err;
201 as->suspend_state = SUSPEND_DONE;
202 }
203 up_read(&user_list_lock);
204
205 wake_up(&apm_suspend_waitqueue);
206}
207
208static ssize_t apm_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
209{
210 struct apm_user *as = fp->private_data;
211 apm_event_t event;
212 int i = count, ret = 0;
213
214 if (count < sizeof(apm_event_t))
215 return -EINVAL;
216
217 if (queue_empty(&as->queue) && fp->f_flags & O_NONBLOCK)
218 return -EAGAIN;
219
220 wait_event_interruptible(apm_waitqueue, !queue_empty(&as->queue));
221
222 while ((i >= sizeof(event)) && !queue_empty(&as->queue)) {
223 event = queue_get_event(&as->queue);
224
225 ret = -EFAULT;
226 if (copy_to_user(buf, &event, sizeof(event)))
227 break;
228
229 if (event == APM_SYS_SUSPEND || event == APM_USER_SUSPEND)
230 as->suspend_state = SUSPEND_READ;
231
232 buf += sizeof(event);
233 i -= sizeof(event);
234 }
235
236 if (i < count)
237 ret = count - i;
238
239 return ret;
240}
241
242static unsigned int apm_poll(struct file *fp, poll_table * wait)
243{
244 struct apm_user *as = fp->private_data;
245
246 poll_wait(fp, &apm_waitqueue, wait);
247 return queue_empty(&as->queue) ? 0 : POLLIN | POLLRDNORM;
248}
249
250/*
251 * apm_ioctl - handle APM ioctl
252 *
253 * APM_IOC_SUSPEND
254 * This IOCTL is overloaded, and performs two functions. It is used to:
255 * - initiate a suspend
256 * - acknowledge a suspend read from /dev/apm_bios.
257 * Only when everyone who has opened /dev/apm_bios with write permission
258 * has acknowledge does the actual suspend happen.
259 */
260static int
261apm_ioctl(struct inode * inode, struct file *filp, u_int cmd, u_long arg)
262{
263 struct apm_user *as = filp->private_data;
264 unsigned long flags;
265 int err = -EINVAL;
266
267 if (!as->suser || !as->writer)
268 return -EPERM;
269
270 switch (cmd) {
271 case APM_IOC_SUSPEND:
272 as->suspend_result = -EINTR;
273
274 if (as->suspend_state == SUSPEND_READ) {
275 /*
276 * If we read a suspend command from /dev/apm_bios,
277 * then the corresponding APM_IOC_SUSPEND ioctl is
278 * interpreted as an acknowledge.
279 */
280 as->suspend_state = SUSPEND_ACKED;
281 suspends_pending--;
282 } else {
283 /*
284 * Otherwise it is a request to suspend the system.
285 * Queue an event for all readers, and expect an
286 * acknowledge from all writers who haven't already
287 * acknowledged.
288 */
289 queue_event(APM_USER_SUSPEND, as);
290 }
291
292 /*
293 * If there are no further acknowledges required, suspend
294 * the system.
295 */
296 if (suspends_pending == 0)
297 apm_suspend();
298
299 /*
300 * Wait for the suspend/resume to complete. If there are
301 * pending acknowledges, we wait here for them.
302 *
303 * Note that we need to ensure that the PM subsystem does
304 * not kick us out of the wait when it suspends the threads.
305 */
306 flags = current->flags;
307 current->flags |= PF_NOFREEZE;
308
309 /*
310 * Note: do not allow a thread which is acking the suspend
311 * to escape until the resume is complete.
312 */
313 if (as->suspend_state == SUSPEND_ACKED)
314 wait_event(apm_suspend_waitqueue,
315 as->suspend_state == SUSPEND_DONE);
316 else
317 wait_event_interruptible(apm_suspend_waitqueue,
318 as->suspend_state == SUSPEND_DONE);
319
320 current->flags = flags;
321 err = as->suspend_result;
322 as->suspend_state = SUSPEND_NONE;
323 break;
324 }
325
326 return err;
327}
328
329static int apm_release(struct inode * inode, struct file * filp)
330{
331 struct apm_user *as = filp->private_data;
332 filp->private_data = NULL;
333
334 down_write(&user_list_lock);
335 list_del(&as->list);
336 up_write(&user_list_lock);
337
338 /*
339 * We are now unhooked from the chain. As far as new
340 * events are concerned, we no longer exist. However, we
341 * need to balance suspends_pending, which means the
342 * possibility of sleeping.
343 */
344 if (as->suspend_state != SUSPEND_NONE) {
345 suspends_pending -= 1;
346 if (suspends_pending == 0)
347 apm_suspend();
348 }
349
350 kfree(as);
351 return 0;
352}
353
354static int apm_open(struct inode * inode, struct file * filp)
355{
356 struct apm_user *as;
357
358 as = (struct apm_user *)kmalloc(sizeof(*as), GFP_KERNEL);
359 if (as) {
360 memset(as, 0, sizeof(*as));
361
362 /*
363 * XXX - this is a tiny bit broken, when we consider BSD
364 * process accounting. If the device is opened by root, we
365 * instantly flag that we used superuser privs. Who knows,
366 * we might close the device immediately without doing a
367 * privileged operation -- cevans
368 */
369 as->suser = capable(CAP_SYS_ADMIN);
370 as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
371 as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
372
373 down_write(&user_list_lock);
374 list_add(&as->list, &apm_user_list);
375 up_write(&user_list_lock);
376
377 filp->private_data = as;
378 }
379
380 return as ? 0 : -ENOMEM;
381}
382
383static struct file_operations apm_bios_fops = {
384 .owner = THIS_MODULE,
385 .read = apm_read,
386 .poll = apm_poll,
387 .ioctl = apm_ioctl,
388 .open = apm_open,
389 .release = apm_release,
390};
391
392static struct miscdevice apm_device = {
393 .minor = APM_MINOR_DEV,
394 .name = "apm_bios",
395 .fops = &apm_bios_fops
396};
397
398
399#ifdef CONFIG_PROC_FS
400/*
401 * Arguments, with symbols from linux/apm_bios.h.
402 *
403 * 0) Linux driver version (this will change if format changes)
404 * 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2.
405 * 2) APM flags from APM Installation Check (0x00):
406 * bit 0: APM_16_BIT_SUPPORT
407 * bit 1: APM_32_BIT_SUPPORT
408 * bit 2: APM_IDLE_SLOWS_CLOCK
409 * bit 3: APM_BIOS_DISABLED
410 * bit 4: APM_BIOS_DISENGAGED
411 * 3) AC line status
412 * 0x00: Off-line
413 * 0x01: On-line
414 * 0x02: On backup power (BIOS >= 1.1 only)
415 * 0xff: Unknown
416 * 4) Battery status
417 * 0x00: High
418 * 0x01: Low
419 * 0x02: Critical
420 * 0x03: Charging
421 * 0x04: Selected battery not present (BIOS >= 1.2 only)
422 * 0xff: Unknown
423 * 5) Battery flag
424 * bit 0: High
425 * bit 1: Low
426 * bit 2: Critical
427 * bit 3: Charging
428 * bit 7: No system battery
429 * 0xff: Unknown
430 * 6) Remaining battery life (percentage of charge):
431 * 0-100: valid
432 * -1: Unknown
433 * 7) Remaining battery life (time units):
434 * Number of remaining minutes or seconds
435 * -1: Unknown
436 * 8) min = minutes; sec = seconds
437 */
438static int apm_get_info(char *buf, char **start, off_t fpos, int length)
439{
440 struct apm_power_info info;
441 char *units;
442 int ret;
443
444 info.ac_line_status = 0xff;
445 info.battery_status = 0xff;
446 info.battery_flag = 0xff;
447 info.battery_life = -1;
448 info.time = -1;
449 info.units = -1;
450
451 if (apm_get_power_status)
452 apm_get_power_status(&info);
453
454 switch (info.units) {
455 default: units = "?"; break;
456 case 0: units = "min"; break;
457 case 1: units = "sec"; break;
458 }
459
460 ret = sprintf(buf, "%s 1.2 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
461 driver_version, APM_32_BIT_SUPPORT,
462 info.ac_line_status, info.battery_status,
463 info.battery_flag, info.battery_life,
464 info.time, units);
465
466 return ret;
467}
468#endif
469
470static int kapmd(void *arg)
471{
472 daemonize("kapmd");
473 current->flags |= PF_NOFREEZE;
474
475 do {
476 apm_event_t event;
477
478 wait_event_interruptible(kapmd_wait,
479 !queue_empty(&kapmd_queue) || !pm_active);
480
481 if (!pm_active)
482 break;
483
484 spin_lock_irq(&kapmd_queue_lock);
485 event = 0;
486 if (!queue_empty(&kapmd_queue))
487 event = queue_get_event(&kapmd_queue);
488 spin_unlock_irq(&kapmd_queue_lock);
489
490 switch (event) {
491 case 0:
492 break;
493
494 case APM_LOW_BATTERY:
495 case APM_POWER_STATUS_CHANGE:
496 queue_event(event, NULL);
497 break;
498
499 case APM_USER_SUSPEND:
500 case APM_SYS_SUSPEND:
501 queue_event(event, NULL);
502 if (suspends_pending == 0)
503 apm_suspend();
504 break;
505
506 case APM_CRITICAL_SUSPEND:
507 apm_suspend();
508 break;
509 }
510 } while (1);
511
512 complete_and_exit(&kapmd_exit, 0);
513}
514
515static int __init apm_init(void)
516{
517 int ret;
518
519 if (apm_disabled) {
520 printk(KERN_NOTICE "apm: disabled on user request.\n");
521 return -ENODEV;
522 }
523
524 if (PM_IS_ACTIVE()) {
525 printk(KERN_NOTICE "apm: overridden by ACPI.\n");
526 return -EINVAL;
527 }
528
529 pm_active = 1;
530
531 ret = kernel_thread(kapmd, NULL, CLONE_KERNEL);
532 if (ret < 0) {
533 pm_active = 0;
534 return ret;
535 }
536
537#ifdef CONFIG_PROC_FS
538 create_proc_info_entry("apm", 0, NULL, apm_get_info);
539#endif
540
541 ret = misc_register(&apm_device);
542 if (ret != 0) {
543 remove_proc_entry("apm", NULL);
544
545 pm_active = 0;
546 wake_up(&kapmd_wait);
547 wait_for_completion(&kapmd_exit);
548 }
549
550 return ret;
551}
552
553static void __exit apm_exit(void)
554{
555 misc_deregister(&apm_device);
556 remove_proc_entry("apm", NULL);
557
558 pm_active = 0;
559 wake_up(&kapmd_wait);
560 wait_for_completion(&kapmd_exit);
561}
562
563module_init(apm_init);
564module_exit(apm_exit);
565
566MODULE_AUTHOR("Stephen Rothwell");
567MODULE_DESCRIPTION("Advanced Power Management");
568MODULE_LICENSE("GPL");
569
570#ifndef MODULE
571static int __init apm_setup(char *str)
572{
573 while ((str != NULL) && (*str != '\0')) {
574 if (strncmp(str, "off", 3) == 0)
575 apm_disabled = 1;
576 if (strncmp(str, "on", 2) == 0)
577 apm_disabled = 0;
578 str = strchr(str, ',');
579 if (str != NULL)
580 str += strspn(str, ", \t");
581 }
582 return 1;
583}
584
585__setup("apm=", apm_setup);
586#endif
587
588/**
589 * apm_queue_event - queue an APM event for kapmd
590 * @event: APM event
591 *
592 * Queue an APM event for kapmd to process and ultimately take the
593 * appropriate action. Only a subset of events are handled:
594 * %APM_LOW_BATTERY
595 * %APM_POWER_STATUS_CHANGE
596 * %APM_USER_SUSPEND
597 * %APM_SYS_SUSPEND
598 * %APM_CRITICAL_SUSPEND
599 */
600void apm_queue_event(apm_event_t event)
601{
602 unsigned long flags;
603
604 spin_lock_irqsave(&kapmd_queue_lock, flags);
605 queue_add_event(&kapmd_queue, event);
606 spin_unlock_irqrestore(&kapmd_queue_lock, flags);
607
608 wake_up_interruptible(&kapmd_wait);
609}
610EXPORT_SYMBOL(apm_queue_event);