| 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/module.h> |
| 14 | #include <linux/poll.h> |
| 15 | #include <linux/slab.h> |
| 16 | #include <linux/proc_fs.h> |
| 17 | #include <linux/miscdevice.h> |
| 18 | #include <linux/apm_bios.h> |
| 19 | #include <linux/capability.h> |
| 20 | #include <linux/sched.h> |
| 21 | #include <linux/pm.h> |
| 22 | #include <linux/apm-emulation.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 | #include <linux/kthread.h> |
| 29 | #include <linux/delay.h> |
| 30 | |
| 31 | #include <asm/system.h> |
| 32 | |
| 33 | /* |
| 34 | * The apm_bios device is one of the misc char devices. |
| 35 | * This is its minor number. |
| 36 | */ |
| 37 | #define APM_MINOR_DEV 134 |
| 38 | |
| 39 | /* |
| 40 | * See Documentation/Config.help for the configuration options. |
| 41 | * |
| 42 | * Various options can be changed at boot time as follows: |
| 43 | * (We allow underscores for compatibility with the modules code) |
| 44 | * apm=on/off enable/disable APM |
| 45 | */ |
| 46 | |
| 47 | /* |
| 48 | * Maximum number of events stored |
| 49 | */ |
| 50 | #define APM_MAX_EVENTS 16 |
| 51 | |
| 52 | struct apm_queue { |
| 53 | unsigned int event_head; |
| 54 | unsigned int event_tail; |
| 55 | apm_event_t events[APM_MAX_EVENTS]; |
| 56 | }; |
| 57 | |
| 58 | /* |
| 59 | * The per-file APM data |
| 60 | */ |
| 61 | struct apm_user { |
| 62 | struct list_head list; |
| 63 | |
| 64 | unsigned int suser: 1; |
| 65 | unsigned int writer: 1; |
| 66 | unsigned int reader: 1; |
| 67 | |
| 68 | int suspend_result; |
| 69 | unsigned int suspend_state; |
| 70 | #define SUSPEND_NONE 0 /* no suspend pending */ |
| 71 | #define SUSPEND_PENDING 1 /* suspend pending read */ |
| 72 | #define SUSPEND_READ 2 /* suspend read, pending ack */ |
| 73 | #define SUSPEND_ACKED 3 /* suspend acked */ |
| 74 | #define SUSPEND_WAIT 4 /* waiting for suspend */ |
| 75 | #define SUSPEND_DONE 5 /* suspend completed */ |
| 76 | |
| 77 | struct apm_queue queue; |
| 78 | }; |
| 79 | |
| 80 | /* |
| 81 | * Local variables |
| 82 | */ |
| 83 | static int suspends_pending; |
| 84 | static int apm_disabled; |
| 85 | static struct task_struct *kapmd_tsk; |
| 86 | |
| 87 | static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue); |
| 88 | static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue); |
| 89 | |
| 90 | /* |
| 91 | * This is a list of everyone who has opened /dev/apm_bios |
| 92 | */ |
| 93 | static DECLARE_RWSEM(user_list_lock); |
| 94 | static LIST_HEAD(apm_user_list); |
| 95 | |
| 96 | /* |
| 97 | * kapmd info. kapmd provides us a process context to handle |
| 98 | * "APM" events within - specifically necessary if we're going |
| 99 | * to be suspending the system. |
| 100 | */ |
| 101 | static DECLARE_WAIT_QUEUE_HEAD(kapmd_wait); |
| 102 | static DEFINE_SPINLOCK(kapmd_queue_lock); |
| 103 | static struct apm_queue kapmd_queue; |
| 104 | |
| 105 | static DEFINE_MUTEX(state_lock); |
| 106 | |
| 107 | static const char driver_version[] = "1.13"; /* no spaces */ |
| 108 | |
| 109 | |
| 110 | |
| 111 | /* |
| 112 | * Compatibility cruft until the IPAQ people move over to the new |
| 113 | * interface. |
| 114 | */ |
| 115 | static void __apm_get_power_status(struct apm_power_info *info) |
| 116 | { |
| 117 | } |
| 118 | |
| 119 | /* |
| 120 | * This allows machines to provide their own "apm get power status" function. |
| 121 | */ |
| 122 | void (*apm_get_power_status)(struct apm_power_info *) = __apm_get_power_status; |
| 123 | EXPORT_SYMBOL(apm_get_power_status); |
| 124 | |
| 125 | |
| 126 | /* |
| 127 | * APM event queue management. |
| 128 | */ |
| 129 | static inline int queue_empty(struct apm_queue *q) |
| 130 | { |
| 131 | return q->event_head == q->event_tail; |
| 132 | } |
| 133 | |
| 134 | static inline apm_event_t queue_get_event(struct apm_queue *q) |
| 135 | { |
| 136 | q->event_tail = (q->event_tail + 1) % APM_MAX_EVENTS; |
| 137 | return q->events[q->event_tail]; |
| 138 | } |
| 139 | |
| 140 | static void queue_add_event(struct apm_queue *q, apm_event_t event) |
| 141 | { |
| 142 | q->event_head = (q->event_head + 1) % APM_MAX_EVENTS; |
| 143 | if (q->event_head == q->event_tail) { |
| 144 | static int notified; |
| 145 | |
| 146 | if (notified++ == 0) |
| 147 | printk(KERN_ERR "apm: an event queue overflowed\n"); |
| 148 | q->event_tail = (q->event_tail + 1) % APM_MAX_EVENTS; |
| 149 | } |
| 150 | q->events[q->event_head] = event; |
| 151 | } |
| 152 | |
| 153 | static void queue_event(apm_event_t event) |
| 154 | { |
| 155 | struct apm_user *as; |
| 156 | |
| 157 | down_read(&user_list_lock); |
| 158 | list_for_each_entry(as, &apm_user_list, list) { |
| 159 | if (as->reader) |
| 160 | queue_add_event(&as->queue, event); |
| 161 | } |
| 162 | up_read(&user_list_lock); |
| 163 | wake_up_interruptible(&apm_waitqueue); |
| 164 | } |
| 165 | |
| 166 | /* |
| 167 | * queue_suspend_event - queue an APM suspend event. |
| 168 | * |
| 169 | * Check that we're in a state where we can suspend. If not, |
| 170 | * return -EBUSY. Otherwise, queue an event to all "writer" |
| 171 | * users. If there are no "writer" users, return '1' to |
| 172 | * indicate that we can immediately suspend. |
| 173 | */ |
| 174 | static int queue_suspend_event(apm_event_t event, struct apm_user *sender) |
| 175 | { |
| 176 | struct apm_user *as; |
| 177 | int ret = 1; |
| 178 | |
| 179 | mutex_lock(&state_lock); |
| 180 | down_read(&user_list_lock); |
| 181 | |
| 182 | /* |
| 183 | * If a thread is still processing, we can't suspend, so reject |
| 184 | * the request. |
| 185 | */ |
| 186 | list_for_each_entry(as, &apm_user_list, list) { |
| 187 | if (as != sender && as->reader && as->writer && as->suser && |
| 188 | as->suspend_state != SUSPEND_NONE) { |
| 189 | ret = -EBUSY; |
| 190 | goto out; |
| 191 | } |
| 192 | } |
| 193 | |
| 194 | list_for_each_entry(as, &apm_user_list, list) { |
| 195 | if (as != sender && as->reader && as->writer && as->suser) { |
| 196 | as->suspend_state = SUSPEND_PENDING; |
| 197 | suspends_pending++; |
| 198 | queue_add_event(&as->queue, event); |
| 199 | ret = 0; |
| 200 | } |
| 201 | } |
| 202 | out: |
| 203 | up_read(&user_list_lock); |
| 204 | mutex_unlock(&state_lock); |
| 205 | wake_up_interruptible(&apm_waitqueue); |
| 206 | return ret; |
| 207 | } |
| 208 | |
| 209 | static void apm_suspend(void) |
| 210 | { |
| 211 | struct apm_user *as; |
| 212 | int err = pm_suspend(PM_SUSPEND_MEM); |
| 213 | |
| 214 | /* |
| 215 | * Anyone on the APM queues will think we're still suspended. |
| 216 | * Send a message so everyone knows we're now awake again. |
| 217 | */ |
| 218 | queue_event(APM_NORMAL_RESUME); |
| 219 | |
| 220 | /* |
| 221 | * Finally, wake up anyone who is sleeping on the suspend. |
| 222 | */ |
| 223 | mutex_lock(&state_lock); |
| 224 | down_read(&user_list_lock); |
| 225 | list_for_each_entry(as, &apm_user_list, list) { |
| 226 | if (as->suspend_state == SUSPEND_WAIT || |
| 227 | as->suspend_state == SUSPEND_ACKED) { |
| 228 | as->suspend_result = err; |
| 229 | as->suspend_state = SUSPEND_DONE; |
| 230 | } |
| 231 | } |
| 232 | up_read(&user_list_lock); |
| 233 | mutex_unlock(&state_lock); |
| 234 | |
| 235 | wake_up(&apm_suspend_waitqueue); |
| 236 | } |
| 237 | |
| 238 | static ssize_t apm_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos) |
| 239 | { |
| 240 | struct apm_user *as = fp->private_data; |
| 241 | apm_event_t event; |
| 242 | int i = count, ret = 0; |
| 243 | |
| 244 | if (count < sizeof(apm_event_t)) |
| 245 | return -EINVAL; |
| 246 | |
| 247 | if (queue_empty(&as->queue) && fp->f_flags & O_NONBLOCK) |
| 248 | return -EAGAIN; |
| 249 | |
| 250 | wait_event_interruptible(apm_waitqueue, !queue_empty(&as->queue)); |
| 251 | |
| 252 | while ((i >= sizeof(event)) && !queue_empty(&as->queue)) { |
| 253 | event = queue_get_event(&as->queue); |
| 254 | |
| 255 | ret = -EFAULT; |
| 256 | if (copy_to_user(buf, &event, sizeof(event))) |
| 257 | break; |
| 258 | |
| 259 | mutex_lock(&state_lock); |
| 260 | if (as->suspend_state == SUSPEND_PENDING && |
| 261 | (event == APM_SYS_SUSPEND || event == APM_USER_SUSPEND)) |
| 262 | as->suspend_state = SUSPEND_READ; |
| 263 | mutex_unlock(&state_lock); |
| 264 | |
| 265 | buf += sizeof(event); |
| 266 | i -= sizeof(event); |
| 267 | } |
| 268 | |
| 269 | if (i < count) |
| 270 | ret = count - i; |
| 271 | |
| 272 | return ret; |
| 273 | } |
| 274 | |
| 275 | static unsigned int apm_poll(struct file *fp, poll_table * wait) |
| 276 | { |
| 277 | struct apm_user *as = fp->private_data; |
| 278 | |
| 279 | poll_wait(fp, &apm_waitqueue, wait); |
| 280 | return queue_empty(&as->queue) ? 0 : POLLIN | POLLRDNORM; |
| 281 | } |
| 282 | |
| 283 | /* |
| 284 | * apm_ioctl - handle APM ioctl |
| 285 | * |
| 286 | * APM_IOC_SUSPEND |
| 287 | * This IOCTL is overloaded, and performs two functions. It is used to: |
| 288 | * - initiate a suspend |
| 289 | * - acknowledge a suspend read from /dev/apm_bios. |
| 290 | * Only when everyone who has opened /dev/apm_bios with write permission |
| 291 | * has acknowledge does the actual suspend happen. |
| 292 | */ |
| 293 | static int |
| 294 | apm_ioctl(struct inode * inode, struct file *filp, u_int cmd, u_long arg) |
| 295 | { |
| 296 | struct apm_user *as = filp->private_data; |
| 297 | unsigned long flags; |
| 298 | int err = -EINVAL; |
| 299 | |
| 300 | if (!as->suser || !as->writer) |
| 301 | return -EPERM; |
| 302 | |
| 303 | switch (cmd) { |
| 304 | case APM_IOC_SUSPEND: |
| 305 | mutex_lock(&state_lock); |
| 306 | |
| 307 | as->suspend_result = -EINTR; |
| 308 | |
| 309 | if (as->suspend_state == SUSPEND_READ) { |
| 310 | int pending; |
| 311 | |
| 312 | /* |
| 313 | * If we read a suspend command from /dev/apm_bios, |
| 314 | * then the corresponding APM_IOC_SUSPEND ioctl is |
| 315 | * interpreted as an acknowledge. |
| 316 | */ |
| 317 | as->suspend_state = SUSPEND_ACKED; |
| 318 | suspends_pending--; |
| 319 | pending = suspends_pending == 0; |
| 320 | mutex_unlock(&state_lock); |
| 321 | |
| 322 | /* |
| 323 | * If there are no further acknowledges required, |
| 324 | * suspend the system. |
| 325 | */ |
| 326 | if (pending) |
| 327 | apm_suspend(); |
| 328 | |
| 329 | /* |
| 330 | * Wait for the suspend/resume to complete. If there |
| 331 | * are pending acknowledges, we wait here for them. |
| 332 | * |
| 333 | * Note: we need to ensure that the PM subsystem does |
| 334 | * not kick us out of the wait when it suspends the |
| 335 | * threads. |
| 336 | */ |
| 337 | flags = current->flags; |
| 338 | current->flags |= PF_NOFREEZE; |
| 339 | |
| 340 | wait_event(apm_suspend_waitqueue, |
| 341 | as->suspend_state == SUSPEND_DONE); |
| 342 | } else { |
| 343 | as->suspend_state = SUSPEND_WAIT; |
| 344 | mutex_unlock(&state_lock); |
| 345 | |
| 346 | /* |
| 347 | * Otherwise it is a request to suspend the system. |
| 348 | * Queue an event for all readers, and expect an |
| 349 | * acknowledge from all writers who haven't already |
| 350 | * acknowledged. |
| 351 | */ |
| 352 | err = queue_suspend_event(APM_USER_SUSPEND, as); |
| 353 | if (err < 0) { |
| 354 | /* |
| 355 | * Avoid taking the lock here - this |
| 356 | * should be fine. |
| 357 | */ |
| 358 | as->suspend_state = SUSPEND_NONE; |
| 359 | break; |
| 360 | } |
| 361 | |
| 362 | if (err > 0) |
| 363 | apm_suspend(); |
| 364 | |
| 365 | /* |
| 366 | * Wait for the suspend/resume to complete. If there |
| 367 | * are pending acknowledges, we wait here for them. |
| 368 | * |
| 369 | * Note: we need to ensure that the PM subsystem does |
| 370 | * not kick us out of the wait when it suspends the |
| 371 | * threads. |
| 372 | */ |
| 373 | flags = current->flags; |
| 374 | current->flags |= PF_NOFREEZE; |
| 375 | |
| 376 | wait_event_interruptible(apm_suspend_waitqueue, |
| 377 | as->suspend_state == SUSPEND_DONE); |
| 378 | } |
| 379 | |
| 380 | current->flags = flags; |
| 381 | |
| 382 | mutex_lock(&state_lock); |
| 383 | err = as->suspend_result; |
| 384 | as->suspend_state = SUSPEND_NONE; |
| 385 | mutex_unlock(&state_lock); |
| 386 | break; |
| 387 | } |
| 388 | |
| 389 | return err; |
| 390 | } |
| 391 | |
| 392 | static int apm_release(struct inode * inode, struct file * filp) |
| 393 | { |
| 394 | struct apm_user *as = filp->private_data; |
| 395 | int pending = 0; |
| 396 | |
| 397 | filp->private_data = NULL; |
| 398 | |
| 399 | down_write(&user_list_lock); |
| 400 | list_del(&as->list); |
| 401 | up_write(&user_list_lock); |
| 402 | |
| 403 | /* |
| 404 | * We are now unhooked from the chain. As far as new |
| 405 | * events are concerned, we no longer exist. However, we |
| 406 | * need to balance suspends_pending, which means the |
| 407 | * possibility of sleeping. |
| 408 | */ |
| 409 | mutex_lock(&state_lock); |
| 410 | if (as->suspend_state != SUSPEND_NONE) { |
| 411 | suspends_pending -= 1; |
| 412 | pending = suspends_pending == 0; |
| 413 | } |
| 414 | mutex_unlock(&state_lock); |
| 415 | if (pending) |
| 416 | apm_suspend(); |
| 417 | |
| 418 | kfree(as); |
| 419 | return 0; |
| 420 | } |
| 421 | |
| 422 | static int apm_open(struct inode * inode, struct file * filp) |
| 423 | { |
| 424 | struct apm_user *as; |
| 425 | |
| 426 | as = kzalloc(sizeof(*as), GFP_KERNEL); |
| 427 | if (as) { |
| 428 | /* |
| 429 | * XXX - this is a tiny bit broken, when we consider BSD |
| 430 | * process accounting. If the device is opened by root, we |
| 431 | * instantly flag that we used superuser privs. Who knows, |
| 432 | * we might close the device immediately without doing a |
| 433 | * privileged operation -- cevans |
| 434 | */ |
| 435 | as->suser = capable(CAP_SYS_ADMIN); |
| 436 | as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE; |
| 437 | as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ; |
| 438 | |
| 439 | down_write(&user_list_lock); |
| 440 | list_add(&as->list, &apm_user_list); |
| 441 | up_write(&user_list_lock); |
| 442 | |
| 443 | filp->private_data = as; |
| 444 | } |
| 445 | |
| 446 | return as ? 0 : -ENOMEM; |
| 447 | } |
| 448 | |
| 449 | static struct file_operations apm_bios_fops = { |
| 450 | .owner = THIS_MODULE, |
| 451 | .read = apm_read, |
| 452 | .poll = apm_poll, |
| 453 | .ioctl = apm_ioctl, |
| 454 | .open = apm_open, |
| 455 | .release = apm_release, |
| 456 | }; |
| 457 | |
| 458 | static struct miscdevice apm_device = { |
| 459 | .minor = APM_MINOR_DEV, |
| 460 | .name = "apm_bios", |
| 461 | .fops = &apm_bios_fops |
| 462 | }; |
| 463 | |
| 464 | |
| 465 | #ifdef CONFIG_PROC_FS |
| 466 | /* |
| 467 | * Arguments, with symbols from linux/apm_bios.h. |
| 468 | * |
| 469 | * 0) Linux driver version (this will change if format changes) |
| 470 | * 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2. |
| 471 | * 2) APM flags from APM Installation Check (0x00): |
| 472 | * bit 0: APM_16_BIT_SUPPORT |
| 473 | * bit 1: APM_32_BIT_SUPPORT |
| 474 | * bit 2: APM_IDLE_SLOWS_CLOCK |
| 475 | * bit 3: APM_BIOS_DISABLED |
| 476 | * bit 4: APM_BIOS_DISENGAGED |
| 477 | * 3) AC line status |
| 478 | * 0x00: Off-line |
| 479 | * 0x01: On-line |
| 480 | * 0x02: On backup power (BIOS >= 1.1 only) |
| 481 | * 0xff: Unknown |
| 482 | * 4) Battery status |
| 483 | * 0x00: High |
| 484 | * 0x01: Low |
| 485 | * 0x02: Critical |
| 486 | * 0x03: Charging |
| 487 | * 0x04: Selected battery not present (BIOS >= 1.2 only) |
| 488 | * 0xff: Unknown |
| 489 | * 5) Battery flag |
| 490 | * bit 0: High |
| 491 | * bit 1: Low |
| 492 | * bit 2: Critical |
| 493 | * bit 3: Charging |
| 494 | * bit 7: No system battery |
| 495 | * 0xff: Unknown |
| 496 | * 6) Remaining battery life (percentage of charge): |
| 497 | * 0-100: valid |
| 498 | * -1: Unknown |
| 499 | * 7) Remaining battery life (time units): |
| 500 | * Number of remaining minutes or seconds |
| 501 | * -1: Unknown |
| 502 | * 8) min = minutes; sec = seconds |
| 503 | */ |
| 504 | static int apm_get_info(char *buf, char **start, off_t fpos, int length) |
| 505 | { |
| 506 | struct apm_power_info info; |
| 507 | char *units; |
| 508 | int ret; |
| 509 | |
| 510 | info.ac_line_status = 0xff; |
| 511 | info.battery_status = 0xff; |
| 512 | info.battery_flag = 0xff; |
| 513 | info.battery_life = -1; |
| 514 | info.time = -1; |
| 515 | info.units = -1; |
| 516 | |
| 517 | if (apm_get_power_status) |
| 518 | apm_get_power_status(&info); |
| 519 | |
| 520 | switch (info.units) { |
| 521 | default: units = "?"; break; |
| 522 | case 0: units = "min"; break; |
| 523 | case 1: units = "sec"; break; |
| 524 | } |
| 525 | |
| 526 | ret = sprintf(buf, "%s 1.2 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n", |
| 527 | driver_version, APM_32_BIT_SUPPORT, |
| 528 | info.ac_line_status, info.battery_status, |
| 529 | info.battery_flag, info.battery_life, |
| 530 | info.time, units); |
| 531 | |
| 532 | return ret; |
| 533 | } |
| 534 | #endif |
| 535 | |
| 536 | static int kapmd(void *arg) |
| 537 | { |
| 538 | do { |
| 539 | apm_event_t event; |
| 540 | int ret; |
| 541 | |
| 542 | wait_event_interruptible(kapmd_wait, |
| 543 | !queue_empty(&kapmd_queue) || kthread_should_stop()); |
| 544 | |
| 545 | if (kthread_should_stop()) |
| 546 | break; |
| 547 | |
| 548 | spin_lock_irq(&kapmd_queue_lock); |
| 549 | event = 0; |
| 550 | if (!queue_empty(&kapmd_queue)) |
| 551 | event = queue_get_event(&kapmd_queue); |
| 552 | spin_unlock_irq(&kapmd_queue_lock); |
| 553 | |
| 554 | switch (event) { |
| 555 | case 0: |
| 556 | break; |
| 557 | |
| 558 | case APM_LOW_BATTERY: |
| 559 | case APM_POWER_STATUS_CHANGE: |
| 560 | queue_event(event); |
| 561 | break; |
| 562 | |
| 563 | case APM_USER_SUSPEND: |
| 564 | case APM_SYS_SUSPEND: |
| 565 | ret = queue_suspend_event(event, NULL); |
| 566 | if (ret < 0) { |
| 567 | /* |
| 568 | * We were busy. Try again in 50ms. |
| 569 | */ |
| 570 | queue_add_event(&kapmd_queue, event); |
| 571 | msleep(50); |
| 572 | } |
| 573 | if (ret > 0) |
| 574 | apm_suspend(); |
| 575 | break; |
| 576 | |
| 577 | case APM_CRITICAL_SUSPEND: |
| 578 | apm_suspend(); |
| 579 | break; |
| 580 | } |
| 581 | } while (1); |
| 582 | |
| 583 | return 0; |
| 584 | } |
| 585 | |
| 586 | static int __init apm_init(void) |
| 587 | { |
| 588 | int ret; |
| 589 | |
| 590 | if (apm_disabled) { |
| 591 | printk(KERN_NOTICE "apm: disabled on user request.\n"); |
| 592 | return -ENODEV; |
| 593 | } |
| 594 | |
| 595 | kapmd_tsk = kthread_create(kapmd, NULL, "kapmd"); |
| 596 | if (IS_ERR(kapmd_tsk)) { |
| 597 | ret = PTR_ERR(kapmd_tsk); |
| 598 | kapmd_tsk = NULL; |
| 599 | return ret; |
| 600 | } |
| 601 | kapmd_tsk->flags |= PF_NOFREEZE; |
| 602 | wake_up_process(kapmd_tsk); |
| 603 | |
| 604 | #ifdef CONFIG_PROC_FS |
| 605 | create_proc_info_entry("apm", 0, NULL, apm_get_info); |
| 606 | #endif |
| 607 | |
| 608 | ret = misc_register(&apm_device); |
| 609 | if (ret != 0) { |
| 610 | remove_proc_entry("apm", NULL); |
| 611 | kthread_stop(kapmd_tsk); |
| 612 | } |
| 613 | |
| 614 | return ret; |
| 615 | } |
| 616 | |
| 617 | static void __exit apm_exit(void) |
| 618 | { |
| 619 | misc_deregister(&apm_device); |
| 620 | remove_proc_entry("apm", NULL); |
| 621 | |
| 622 | kthread_stop(kapmd_tsk); |
| 623 | } |
| 624 | |
| 625 | module_init(apm_init); |
| 626 | module_exit(apm_exit); |
| 627 | |
| 628 | MODULE_AUTHOR("Stephen Rothwell"); |
| 629 | MODULE_DESCRIPTION("Advanced Power Management"); |
| 630 | MODULE_LICENSE("GPL"); |
| 631 | |
| 632 | #ifndef MODULE |
| 633 | static int __init apm_setup(char *str) |
| 634 | { |
| 635 | while ((str != NULL) && (*str != '\0')) { |
| 636 | if (strncmp(str, "off", 3) == 0) |
| 637 | apm_disabled = 1; |
| 638 | if (strncmp(str, "on", 2) == 0) |
| 639 | apm_disabled = 0; |
| 640 | str = strchr(str, ','); |
| 641 | if (str != NULL) |
| 642 | str += strspn(str, ", \t"); |
| 643 | } |
| 644 | return 1; |
| 645 | } |
| 646 | |
| 647 | __setup("apm=", apm_setup); |
| 648 | #endif |
| 649 | |
| 650 | /** |
| 651 | * apm_queue_event - queue an APM event for kapmd |
| 652 | * @event: APM event |
| 653 | * |
| 654 | * Queue an APM event for kapmd to process and ultimately take the |
| 655 | * appropriate action. Only a subset of events are handled: |
| 656 | * %APM_LOW_BATTERY |
| 657 | * %APM_POWER_STATUS_CHANGE |
| 658 | * %APM_USER_SUSPEND |
| 659 | * %APM_SYS_SUSPEND |
| 660 | * %APM_CRITICAL_SUSPEND |
| 661 | */ |
| 662 | void apm_queue_event(apm_event_t event) |
| 663 | { |
| 664 | unsigned long flags; |
| 665 | |
| 666 | spin_lock_irqsave(&kapmd_queue_lock, flags); |
| 667 | queue_add_event(&kapmd_queue, event); |
| 668 | spin_unlock_irqrestore(&kapmd_queue_lock, flags); |
| 669 | |
| 670 | wake_up_interruptible(&kapmd_wait); |
| 671 | } |
| 672 | EXPORT_SYMBOL(apm_queue_event); |