2 * APM BIOS driver for Linux
3 * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
5 * Initial development of this driver was funded by NEC Australia P/L
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2, or (at your option) any
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
18 * October 1995, Rik Faith (faith@cs.unc.edu):
19 * Minor enhancements and updates (to the patch set) for 1.3.x
21 * January 1996, Rik Faith (faith@cs.unc.edu):
22 * Make /proc/apm easy to format (bump driver version)
23 * March 1996, Rik Faith (faith@cs.unc.edu):
24 * Prohibit APM BIOS calls unless apm_enabled.
25 * (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
26 * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
28 * May 1996, Version 1.2
29 * Feb 1998, Version 1.3
30 * Feb 1998, Version 1.4
31 * Aug 1998, Version 1.5
32 * Sep 1998, Version 1.6
33 * Nov 1998, Version 1.7
34 * Jan 1999, Version 1.8
35 * Jan 1999, Version 1.9
36 * Oct 1999, Version 1.10
37 * Nov 1999, Version 1.11
38 * Jan 2000, Version 1.12
39 * Feb 2000, Version 1.13
40 * Nov 2000, Version 1.14
41 * Oct 2001, Version 1.15
42 * Jan 2002, Version 1.16
43 * Oct 2002, Version 1.16ac
46 * 0.6b: first version in official kernel, Linux 1.3.46
47 * 0.7: changed /proc/apm format, Linux 1.3.58
48 * 0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
49 * 0.9: only call bios if bios is present, Linux 1.3.72
50 * 1.0: use fixed device number, consolidate /proc/apm into this file,
52 * 1.1: support user-space standby and suspend, power off after system
53 * halted, Linux 1.3.98
54 * 1.2: When resetting RTC after resume, take care so that the time
55 * is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
56 * <jtoth@princeton.edu>); improve interaction between
57 * screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
58 * 1.2a:Simple change to stop mysterious bug reports with SMP also added
59 * levels to the printk calls. APM is not defined for SMP machines.
60 * The new replacement for it is, but Linux doesn't yet support this.
61 * Alan Cox Linux 2.1.55
62 * 1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
63 * 1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
64 * Dean Gaudet <dgaudet@arctic.org>.
65 * C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
66 * 1.5: Fix segment register reloading (in case of bad segments saved
69 * 1.6: Cope with complier/assembler differences.
70 * Only try to turn off the first display device.
71 * Fix OOPS at power off with no APM BIOS by Jan Echternach
72 * <echter@informatik.uni-rostock.de>
74 * 1.7: Modify driver's cached copy of the disabled/disengaged flags
75 * to reflect current state of APM BIOS.
76 * Chris Rankin <rankinc@bellsouth.net>
77 * Reset interrupt 0 timer to 100Hz after suspend
78 * Chad Miller <cmiller@surfsouth.com>
79 * Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
80 * Richard Gooch <rgooch@atnf.csiro.au>
81 * Allow boot time disabling of APM
82 * Make boot messages far less verbose by default
85 * 1.8: Add CONFIG_APM_RTC_IS_GMT
86 * Richard Gooch <rgooch@atnf.csiro.au>
87 * change APM_NOINTS to CONFIG_APM_ALLOW_INTS
88 * remove dependency on CONFIG_PROC_FS
90 * 1.9: Fix small typo. <laslo@wodip.opole.pl>
91 * Try to cope with BIOS's that need to have all display
92 * devices blanked and not just the first one.
93 * Ross Paterson <ross@soi.city.ac.uk>
94 * Fix segment limit setting it has always been wrong as
95 * the segments needed to have byte granularity.
96 * Mark a few things __init.
97 * Add hack to allow power off of SMP systems by popular request.
98 * Use CONFIG_SMP instead of __SMP__
99 * Ignore BOUNCES for three seconds.
101 * 1.10: Fix for Thinkpad return code.
102 * Merge 2.2 and 2.3 drivers.
103 * Remove APM dependencies in arch/i386/kernel/process.c
104 * Remove APM dependencies in drivers/char/sysrq.c
105 * Reset time across standby.
106 * Allow more inititialisation on SMP.
107 * Remove CONFIG_APM_POWER_OFF and make it boot time
108 * configurable (default on).
109 * Make debug only a boot time parameter (remove APM_DEBUG).
110 * Try to blank all devices on any error.
111 * 1.11: Remove APM dependencies in drivers/char/console.c
112 * Check nr_running to detect if we are idle (from
113 * Borislav Deianov <borislav@lix.polytechnique.fr>)
114 * Fix for bioses that don't zero the top part of the
115 * entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
116 * (reported by Panos Katsaloulis <teras@writeme.com>).
117 * Real mode power off patch (Walter Hofmann
118 * <Walter.Hofmann@physik.stud.uni-erlangen.de>).
119 * 1.12: Remove CONFIG_SMP as the compiler will optimize
120 * the code away anyway (smp_num_cpus == 1 in UP)
121 * noted by Artur Skawina <skawina@geocities.com>.
122 * Make power off under SMP work again.
123 * Fix thinko with initial engaging of BIOS.
124 * Make sure power off only happens on CPU 0
125 * (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
126 * Do error notification to user mode if BIOS calls fail.
127 * Move entrypoint offset fix to ...boot/setup.S
128 * where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
129 * Remove smp-power-off. SMP users must now specify
130 * "apm=power-off" on the kernel command line. Suggested
131 * by Jim Avera <jima@hal.com>, modified by Alan Cox
132 * <alan@lxorguk.ukuu.org.uk>.
133 * Register the /proc/apm entry even on SMP so that
134 * scripts that check for it before doing power off
135 * work (Jim Avera <jima@hal.com>).
136 * 1.13: Changes for new pm_ interfaces (Andy Henroid
137 * <andy_henroid@yahoo.com>).
138 * Modularize the code.
139 * Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
140 * is now the way life works).
141 * Fix thinko in suspend() (wrong return).
142 * Notify drivers on critical suspend.
143 * Make kapmd absorb more idle time (Pavel Machek <pavel@suse.cz>
145 * Disable interrupts while we are suspended (Andy Henroid
146 * <andy_henroid@yahoo.com> fixed by sfr).
147 * Make power off work on SMP again (Tony Hoyle
148 * <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
149 * Remove CONFIG_APM_SUSPEND_BOUNCE. The bounce ignore
150 * interval is now configurable.
151 * 1.14: Make connection version persist across module unload/load.
152 * Enable and engage power management earlier.
153 * Disengage power management on module unload.
154 * Changed to use the sysrq-register hack for registering the
155 * power off function called by magic sysrq based upon discussions
156 * in irc://irc.openprojects.net/#kernelnewbies
157 * (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
158 * Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
159 * (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
160 * Work around byte swap bug in one of the Vaio's BIOS's
161 * (Marc Boucher <marc@mbsi.ca>).
162 * Exposed the disable flag to dmi so that we can handle known
163 * broken APM (Alan Cox <alan@redhat.com>).
164 * 1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
165 * calling it - instead idle. (Alan Cox <alan@redhat.com>)
166 * If an APM idle fails log it and idle sensibly
167 * 1.15: Don't queue events to clients who open the device O_WRONLY.
168 * Don't expect replies from clients who open the device O_RDONLY.
169 * (Idea from Thomas Hood)
170 * Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
171 * 1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
172 * Notify listeners of standby or suspend events before notifying
173 * drivers. Return EBUSY to ioctl() if suspend is rejected.
174 * (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
175 * Ignore first resume after we generate our own resume event
176 * after a suspend (Thomas Hood)
177 * Daemonize now gets rid of our controlling terminal (sfr).
178 * CONFIG_APM_CPU_IDLE now just affects the default value of
179 * idle_threshold (sfr).
180 * Change name of kernel apm daemon (as it no longer idles) (sfr).
181 * 1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
182 * make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
183 * TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
187 * Intel Corporation, Microsoft Corporation. Advanced Power Management
188 * (APM) BIOS Interface Specification, Revision 1.1, September 1993.
189 * Intel Order Number 241704-001. Microsoft Part Number 781-110-X01.
191 * [This document is available free from Intel by calling 800.628.8686 (fax
192 * 916.356.6100) or 800.548.4725; or via anonymous ftp from
193 * ftp://ftp.intel.com/pub/IAL/software_specs/apmv11.doc. It is also
194 * available from Microsoft by calling 206.882.8080.]
197 * Intel Corporation, Microsoft Corporation. Advanced Power Management
198 * (APM) BIOS Interface Specification, Revision 1.2, February 1996.
200 * [This document is available from Microsoft at:
201 * http://www.microsoft.com/whdc/archive/amp_12.mspx]
204 #include <linux/module.h>
206 #include <linux/poll.h>
207 #include <linux/smp_lock.h>
208 #include <linux/types.h>
209 #include <linux/stddef.h>
210 #include <linux/timer.h>
211 #include <linux/fcntl.h>
212 #include <linux/slab.h>
213 #include <linux/stat.h>
214 #include <linux/proc_fs.h>
215 #include <linux/seq_file.h>
216 #include <linux/miscdevice.h>
217 #include <linux/apm_bios.h>
218 #include <linux/init.h>
219 #include <linux/time.h>
220 #include <linux/sched.h>
221 #include <linux/pm.h>
222 #include <linux/capability.h>
223 #include <linux/device.h>
224 #include <linux/kernel.h>
225 #include <linux/freezer.h>
226 #include <linux/smp.h>
227 #include <linux/dmi.h>
228 #include <linux/suspend.h>
229 #include <linux/kthread.h>
230 #include <linux/jiffies.h>
232 #include <asm/system.h>
233 #include <asm/uaccess.h>
234 #include <asm/desc.h>
235 #include <asm/i8253.h>
236 #include <asm/paravirt.h>
237 #include <asm/reboot.h>
239 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
240 extern int (*console_blank_hook)(int);
244 * The apm_bios device is one of the misc char devices.
245 * This is its minor number.
247 #define APM_MINOR_DEV 134
250 * See Documentation/Config.help for the configuration options.
252 * Various options can be changed at boot time as follows:
253 * (We allow underscores for compatibility with the modules code)
254 * apm=on/off enable/disable APM
255 * [no-]allow[-_]ints allow interrupts during BIOS calls
256 * [no-]broken[-_]psr BIOS has a broken GetPowerStatus call
257 * [no-]realmode[-_]power[-_]off switch to real mode before
259 * [no-]debug log some debugging messages
260 * [no-]power[-_]off power off on shutdown
261 * [no-]smp Use apm even on an SMP box
262 * bounce[-_]interval=<n> number of ticks to ignore suspend
264 * idle[-_]threshold=<n> System idle percentage above which to
265 * make APM BIOS idle calls. Set it to
267 * idle[-_]period=<n> Period (in 1/100s of a second) over
268 * which the idle percentage is
272 /* KNOWN PROBLEM MACHINES:
274 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
275 * [Confirmed by TI representative]
276 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
277 * [Confirmed by BIOS disassembly]
278 * [This may work now ...]
279 * P: Toshiba 1950S: battery life information only gets updated after resume
280 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
281 * broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
282 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
283 * Neale Banks <neale@lowendale.com.au> December 2000
285 * Legend: U = unusable with APM patches
286 * P = partially usable with APM patches
290 * Define as 1 to make the driver always call the APM BIOS busy
291 * routine even if the clock was not reported as slowed by the
292 * idle routine. Otherwise, define as 0.
294 #define ALWAYS_CALL_BUSY 1
297 * Define to make the APM BIOS calls zero all data segment registers (so
298 * that an incorrect BIOS implementation will cause a kernel panic if it
299 * tries to write to arbitrary memory).
301 #define APM_ZERO_SEGS
306 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
307 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
308 * David Chen <chen@ctpa04.mit.edu>
310 #undef INIT_TIMER_AFTER_SUSPEND
312 #ifdef INIT_TIMER_AFTER_SUSPEND
313 #include <linux/timex.h>
315 #include <linux/delay.h>
319 * Need to poll the APM BIOS every second
321 #define APM_CHECK_TIMEOUT (HZ)
324 * Ignore suspend events for this amount of time after a resume
326 #define DEFAULT_BOUNCE_INTERVAL (3 * HZ)
329 * Maximum number of events stored
331 #define APM_MAX_EVENTS 20
334 * The per-file APM data
338 struct apm_user *next;
339 unsigned int suser: 1;
340 unsigned int writer: 1;
341 unsigned int reader: 1;
342 unsigned int suspend_wait: 1;
344 int suspends_pending;
345 int standbys_pending;
350 apm_event_t events[APM_MAX_EVENTS];
354 * The magic number in apm_user
356 #define APM_BIOS_MAGIC 0x4101
359 * idle percentage above which bios idle calls are done
361 #ifdef CONFIG_APM_CPU_IDLE
362 #define DEFAULT_IDLE_THRESHOLD 95
364 #define DEFAULT_IDLE_THRESHOLD 100
366 #define DEFAULT_IDLE_PERIOD (100 / 3)
372 unsigned long offset;
373 unsigned short segment;
375 static int clock_slowed;
376 static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
377 static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
378 static int set_pm_idle;
379 static int suspends_pending;
380 static int standbys_pending;
381 static int ignore_sys_suspend;
382 static int ignore_normal_resume;
383 static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
385 static int debug __read_mostly;
386 static int smp __read_mostly;
387 static int apm_disabled = -1;
389 static int power_off;
391 static int power_off = 1;
393 #ifdef CONFIG_APM_REAL_MODE_POWER_OFF
394 static int realmode_power_off = 1;
396 static int realmode_power_off;
398 #ifdef CONFIG_APM_ALLOW_INTS
399 static int allow_ints = 1;
401 static int allow_ints;
403 static int broken_psr;
405 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
406 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
407 static struct apm_user *user_list;
408 static DEFINE_SPINLOCK(user_list_lock);
409 static const struct desc_struct bad_bios_desc = { { { 0, 0x00409200 } } };
411 static const char driver_version[] = "1.16ac"; /* no spaces */
413 static struct task_struct *kapmd_task;
416 * APM event names taken from the APM 1.2 specification. These are
417 * the message codes that the BIOS uses to tell us about events
419 static const char * const apm_event_name[] = {
425 "power status change",
430 "system standby resume",
431 "capabilities change"
433 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
435 typedef struct lookup_t {
441 * The BIOS returns a set of standard error codes in AX when the
445 static const lookup_t error_table[] = {
446 /* N/A { APM_SUCCESS, "Operation succeeded" }, */
447 { APM_DISABLED, "Power management disabled" },
448 { APM_CONNECTED, "Real mode interface already connected" },
449 { APM_NOT_CONNECTED, "Interface not connected" },
450 { APM_16_CONNECTED, "16 bit interface already connected" },
451 /* N/A { APM_16_UNSUPPORTED, "16 bit interface not supported" }, */
452 { APM_32_CONNECTED, "32 bit interface already connected" },
453 { APM_32_UNSUPPORTED, "32 bit interface not supported" },
454 { APM_BAD_DEVICE, "Unrecognized device ID" },
455 { APM_BAD_PARAM, "Parameter out of range" },
456 { APM_NOT_ENGAGED, "Interface not engaged" },
457 { APM_BAD_FUNCTION, "Function not supported" },
458 { APM_RESUME_DISABLED, "Resume timer disabled" },
459 { APM_BAD_STATE, "Unable to enter requested state" },
460 /* N/A { APM_NO_EVENTS, "No events pending" }, */
461 { APM_NO_ERROR, "BIOS did not set a return code" },
462 { APM_NOT_PRESENT, "No APM present" }
464 #define ERROR_COUNT ARRAY_SIZE(error_table)
467 * apm_error - display an APM error
468 * @str: information string
469 * @err: APM BIOS return code
471 * Write a meaningful log entry to the kernel log in the event of
475 static void apm_error(char *str, int err)
479 for (i = 0; i < ERROR_COUNT; i++)
480 if (error_table[i].key == err)
483 printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg);
485 printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n",
490 * Lock APM functionality to physical CPU 0
495 static cpumask_t apm_save_cpus(void)
497 cpumask_t x = current->cpus_allowed;
498 /* Some bioses don't like being called from CPU != 0 */
499 set_cpus_allowed(current, cpumask_of_cpu(0));
500 BUG_ON(smp_processor_id() != 0);
504 static inline void apm_restore_cpus(cpumask_t mask)
506 set_cpus_allowed(current, mask);
512 * No CPU lockdown needed on a uniprocessor
515 #define apm_save_cpus() (current->cpus_allowed)
516 #define apm_restore_cpus(x) (void)(x)
521 * These are the actual BIOS calls. Depending on APM_ZERO_SEGS and
522 * apm_info.allow_ints, we are being really paranoid here! Not only
523 * are interrupts disabled, but all the segment registers (except SS)
524 * are saved and zeroed this means that if the BIOS tries to reference
525 * any data without explicitly loading the segment registers, the kernel
526 * will fault immediately rather than have some unforeseen circumstances
527 * for the rest of the kernel. And it will be very obvious! :-) Doing
528 * this depends on CS referring to the same physical memory as DS so that
529 * DS can be zeroed before the call. Unfortunately, we can't do anything
530 * about the stack segment/pointer. Also, we tell the compiler that
531 * everything could change.
533 * Also, we KNOW that for the non error case of apm_bios_call, there
534 * is no useful data returned in the low order 8 bits of eax.
537 static inline unsigned long __apm_irq_save(void)
540 local_save_flags(flags);
541 if (apm_info.allow_ints) {
542 if (irqs_disabled_flags(flags))
550 #define apm_irq_save(flags) \
551 do { flags = __apm_irq_save(); } while (0)
553 static inline void apm_irq_restore(unsigned long flags)
555 if (irqs_disabled_flags(flags))
557 else if (irqs_disabled())
562 # define APM_DECL_SEGS \
563 unsigned int saved_fs; unsigned int saved_gs;
564 # define APM_DO_SAVE_SEGS \
565 savesegment(fs, saved_fs); savesegment(gs, saved_gs)
566 # define APM_DO_RESTORE_SEGS \
567 loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
569 # define APM_DECL_SEGS
570 # define APM_DO_SAVE_SEGS
571 # define APM_DO_RESTORE_SEGS
575 * apm_bios_call - Make an APM BIOS 32bit call
576 * @func: APM function to execute
577 * @ebx_in: EBX register for call entry
578 * @ecx_in: ECX register for call entry
579 * @eax: EAX register return
580 * @ebx: EBX register return
581 * @ecx: ECX register return
582 * @edx: EDX register return
583 * @esi: ESI register return
585 * Make an APM call using the 32bit protected mode interface. The
586 * caller is responsible for knowing if APM BIOS is configured and
587 * enabled. This call can disable interrupts for a long period of
588 * time on some laptops. The return value is in AH and the carry
589 * flag is loaded into AL. If there is an error, then the error
590 * code is returned in AH (bits 8-15 of eax) and this function
594 static u8 apm_bios_call(u32 func, u32 ebx_in, u32 ecx_in,
595 u32 *eax, u32 *ebx, u32 *ecx, u32 *edx, u32 *esi)
601 struct desc_struct save_desc_40;
602 struct desc_struct *gdt;
604 cpus = apm_save_cpus();
607 gdt = get_cpu_gdt_table(cpu);
608 save_desc_40 = gdt[0x40 / 8];
609 gdt[0x40 / 8] = bad_bios_desc;
613 apm_bios_call_asm(func, ebx_in, ecx_in, eax, ebx, ecx, edx, esi);
615 apm_irq_restore(flags);
616 gdt[0x40 / 8] = save_desc_40;
618 apm_restore_cpus(cpus);
624 * apm_bios_call_simple - make a simple APM BIOS 32bit call
625 * @func: APM function to invoke
626 * @ebx_in: EBX register value for BIOS call
627 * @ecx_in: ECX register value for BIOS call
628 * @eax: EAX register on return from the BIOS call
630 * Make a BIOS call that returns one value only, or just status.
631 * If there is an error, then the error code is returned in AH
632 * (bits 8-15 of eax) and this function returns non-zero. This is
633 * used for simpler BIOS operations. This call may hold interrupts
634 * off for a long time on some laptops.
637 static u8 apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax)
644 struct desc_struct save_desc_40;
645 struct desc_struct *gdt;
647 cpus = apm_save_cpus();
650 gdt = get_cpu_gdt_table(cpu);
651 save_desc_40 = gdt[0x40 / 8];
652 gdt[0x40 / 8] = bad_bios_desc;
656 error = apm_bios_call_simple_asm(func, ebx_in, ecx_in, eax);
658 apm_irq_restore(flags);
659 gdt[0x40 / 8] = save_desc_40;
661 apm_restore_cpus(cpus);
666 * apm_driver_version - APM driver version
667 * @val: loaded with the APM version on return
669 * Retrieve the APM version supported by the BIOS. This is only
670 * supported for APM 1.1 or higher. An error indicates APM 1.0 is
673 * On entry val should point to a value indicating the APM driver
674 * version with the high byte being the major and the low byte the
675 * minor number both in BCD
677 * On return it will hold the BIOS revision supported in the
681 static int apm_driver_version(u_short *val)
685 if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax))
686 return (eax >> 8) & 0xff;
692 * apm_get_event - get an APM event from the BIOS
693 * @event: pointer to the event
694 * @info: point to the event information
696 * The APM BIOS provides a polled information for event
697 * reporting. The BIOS expects to be polled at least every second
698 * when events are pending. When a message is found the caller should
699 * poll until no more messages are present. However, this causes
700 * problems on some laptops where a suspend event notification is
701 * not cleared until it is acknowledged.
703 * Additional information is returned in the info pointer, providing
704 * that APM 1.2 is in use. If no messges are pending the value 0x80
705 * is returned (No power management events pending).
708 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
715 if (apm_bios_call(APM_FUNC_GET_EVENT, 0, 0, &eax, &ebx, &ecx,
717 return (eax >> 8) & 0xff;
719 if (apm_info.connection_version < 0x0102)
720 *info = ~0; /* indicate info not valid */
727 * set_power_state - set the power management state
728 * @what: which items to transition
729 * @state: state to transition to
731 * Request an APM change of state for one or more system devices. The
732 * processor state must be transitioned last of all. what holds the
733 * class of device in the upper byte and the device number (0xFF for
734 * all) for the object to be transitioned.
736 * The state holds the state to transition to, which may in fact
737 * be an acceptance of a BIOS requested state change.
740 static int set_power_state(u_short what, u_short state)
744 if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax))
745 return (eax >> 8) & 0xff;
750 * set_system_power_state - set system wide power state
751 * @state: which state to enter
753 * Transition the entire system into a new APM power state.
756 static int set_system_power_state(u_short state)
758 return set_power_state(APM_DEVICE_ALL, state);
762 * apm_do_idle - perform power saving
764 * This function notifies the BIOS that the processor is (in the view
765 * of the OS) idle. It returns -1 in the event that the BIOS refuses
766 * to handle the idle request. On a success the function returns 1
767 * if the BIOS did clock slowing or 0 otherwise.
770 static int apm_do_idle(void)
777 polling = !!(current_thread_info()->status & TS_POLLING);
779 current_thread_info()->status &= ~TS_POLLING;
781 * TS_POLLING-cleared state must be visible before we
786 if (!need_resched()) {
788 ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax);
791 current_thread_info()->status |= TS_POLLING;
797 static unsigned long t;
799 /* This always fails on some SMP boards running UP kernels.
800 * Only report the failure the first 5 times.
803 printk(KERN_DEBUG "apm_do_idle failed (%d)\n",
809 clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
814 * apm_do_busy - inform the BIOS the CPU is busy
816 * Request that the BIOS brings the CPU back to full performance.
819 static void apm_do_busy(void)
823 if (clock_slowed || ALWAYS_CALL_BUSY) {
824 (void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy);
830 * If no process has really been interested in
831 * the CPU for some time, we want to call BIOS
832 * power management - we probably want
835 #define IDLE_CALC_LIMIT (HZ * 100)
836 #define IDLE_LEAKY_MAX 16
838 static void (*original_pm_idle)(void) __read_mostly;
841 * apm_cpu_idle - cpu idling for APM capable Linux
843 * This is the idling function the kernel executes when APM is available. It
844 * tries to do BIOS powermanagement based on the average system idle time.
845 * Furthermore it calls the system default idle routine.
848 static void apm_cpu_idle(void)
850 static int use_apm_idle; /* = 0 */
851 static unsigned int last_jiffies; /* = 0 */
852 static unsigned int last_stime; /* = 0 */
854 int apm_idle_done = 0;
855 unsigned int jiffies_since_last_check = jiffies - last_jiffies;
859 if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
861 last_jiffies = jiffies;
862 last_stime = current->stime;
863 } else if (jiffies_since_last_check > idle_period) {
864 unsigned int idle_percentage;
866 idle_percentage = current->stime - last_stime;
867 idle_percentage *= 100;
868 idle_percentage /= jiffies_since_last_check;
869 use_apm_idle = (idle_percentage > idle_threshold);
870 if (apm_info.forbid_idle)
872 last_jiffies = jiffies;
873 last_stime = current->stime;
876 bucket = IDLE_LEAKY_MAX;
878 while (!need_resched()) {
883 switch (apm_do_idle()) {
888 bucket = IDLE_LEAKY_MAX;
899 default: /* BIOS refused */
903 if (original_pm_idle)
908 jiffies_since_last_check = jiffies - last_jiffies;
909 if (jiffies_since_last_check > idle_period)
920 * apm_power_off - ask the BIOS to power off
922 * Handle the power off sequence. This is the one piece of code we
923 * will execute even on SMP machines. In order to deal with BIOS
924 * bugs we support real mode APM BIOS power off calls. We also make
925 * the SMP call on CPU0 as some systems will only honour this call
926 * on their first cpu.
929 static void apm_power_off(void)
931 unsigned char po_bios_call[] = {
932 0xb8, 0x00, 0x10, /* movw $0x1000,ax */
933 0x8e, 0xd0, /* movw ax,ss */
934 0xbc, 0x00, 0xf0, /* movw $0xf000,sp */
935 0xb8, 0x07, 0x53, /* movw $0x5307,ax */
936 0xbb, 0x01, 0x00, /* movw $0x0001,bx */
937 0xb9, 0x03, 0x00, /* movw $0x0003,cx */
938 0xcd, 0x15 /* int $0x15 */
941 /* Some bioses don't like being called from CPU != 0 */
942 if (apm_info.realmode_power_off) {
943 (void)apm_save_cpus();
944 machine_real_restart(po_bios_call, sizeof(po_bios_call));
946 (void)set_system_power_state(APM_STATE_OFF);
950 #ifdef CONFIG_APM_DO_ENABLE
953 * apm_enable_power_management - enable BIOS APM power management
954 * @enable: enable yes/no
956 * Enable or disable the APM BIOS power services.
959 static int apm_enable_power_management(int enable)
963 if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
964 return APM_NOT_ENGAGED;
965 if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
967 return (eax >> 8) & 0xff;
969 apm_info.bios.flags &= ~APM_BIOS_DISABLED;
971 apm_info.bios.flags |= APM_BIOS_DISABLED;
977 * apm_get_power_status - get current power state
978 * @status: returned status
980 * @life: estimated life
982 * Obtain the current power status from the APM BIOS. We return a
983 * status which gives the rough battery status, and current power
984 * source. The bat value returned give an estimate as a percentage
985 * of life and a status value for the battery. The estimated life
986 * if reported is a lifetime in secodnds/minutes at current powwer
990 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
998 if (apm_info.get_power_status_broken)
999 return APM_32_UNSUPPORTED;
1000 if (apm_bios_call(APM_FUNC_GET_STATUS, APM_DEVICE_ALL, 0,
1001 &eax, &ebx, &ecx, &edx, &dummy))
1002 return (eax >> 8) & 0xff;
1005 if (apm_info.get_power_status_swabinminutes) {
1006 *life = swab16((u16)edx);
1014 static int apm_get_battery_status(u_short which, u_short *status,
1015 u_short *bat, u_short *life, u_short *nbat)
1023 if (apm_info.connection_version < 0x0102) {
1024 /* pretend we only have one battery. */
1026 return APM_BAD_DEVICE;
1028 return apm_get_power_status(status, bat, life);
1031 if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1032 &ebx, &ecx, &edx, &esi))
1033 return (eax >> 8) & 0xff;
1043 * apm_engage_power_management - enable PM on a device
1044 * @device: identity of device
1047 * Activate or deactive power management on either a specific device
1048 * or the entire system (%APM_DEVICE_ALL).
1051 static int apm_engage_power_management(u_short device, int enable)
1055 if ((enable == 0) && (device == APM_DEVICE_ALL)
1056 && (apm_info.bios.flags & APM_BIOS_DISABLED))
1057 return APM_DISABLED;
1058 if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable, &eax))
1059 return (eax >> 8) & 0xff;
1060 if (device == APM_DEVICE_ALL) {
1062 apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1064 apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1069 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1072 * apm_console_blank - blank the display
1075 * Attempt to blank the console, firstly by blanking just video device
1076 * zero, and if that fails (some BIOSes don't support it) then it blanks
1077 * all video devices. Typically the BIOS will do laptop backlight and
1078 * monitor powerdown for us.
1081 static int apm_console_blank(int blank)
1083 int error = APM_NOT_ENGAGED; /* silence gcc */
1086 static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1088 state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1090 for (i = 0; i < ARRAY_SIZE(dev); i++) {
1091 error = set_power_state(dev[i], state);
1093 if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1096 if (error == APM_NOT_ENGAGED)
1100 if (error == APM_NOT_ENGAGED) {
1104 eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1106 apm_error("set display", error);
1107 apm_error("engage interface", eng_error);
1110 return apm_console_blank(blank);
1113 apm_error("set display", error);
1118 static int queue_empty(struct apm_user *as)
1120 return as->event_head == as->event_tail;
1123 static apm_event_t get_queued_event(struct apm_user *as)
1125 if (++as->event_tail >= APM_MAX_EVENTS)
1127 return as->events[as->event_tail];
1130 static void queue_event(apm_event_t event, struct apm_user *sender)
1132 struct apm_user *as;
1134 spin_lock(&user_list_lock);
1135 if (user_list == NULL)
1137 for (as = user_list; as != NULL; as = as->next) {
1138 if ((as == sender) || (!as->reader))
1140 if (++as->event_head >= APM_MAX_EVENTS)
1143 if (as->event_head == as->event_tail) {
1144 static int notified;
1146 if (notified++ == 0)
1147 printk(KERN_ERR "apm: an event queue overflowed\n");
1148 if (++as->event_tail >= APM_MAX_EVENTS)
1151 as->events[as->event_head] = event;
1152 if (!as->suser || !as->writer)
1155 case APM_SYS_SUSPEND:
1156 case APM_USER_SUSPEND:
1157 as->suspends_pending++;
1161 case APM_SYS_STANDBY:
1162 case APM_USER_STANDBY:
1163 as->standbys_pending++;
1168 wake_up_interruptible(&apm_waitqueue);
1170 spin_unlock(&user_list_lock);
1173 static void reinit_timer(void)
1175 #ifdef INIT_TIMER_AFTER_SUSPEND
1176 unsigned long flags;
1178 spin_lock_irqsave(&i8253_lock, flags);
1179 /* set the clock to HZ */
1180 outb_pit(0x34, PIT_MODE); /* binary, mode 2, LSB/MSB, ch 0 */
1182 outb_pit(LATCH & 0xff, PIT_CH0); /* LSB */
1184 outb_pit(LATCH >> 8, PIT_CH0); /* MSB */
1186 spin_unlock_irqrestore(&i8253_lock, flags);
1190 static int suspend(int vetoable)
1193 struct apm_user *as;
1195 device_suspend(PMSG_SUSPEND);
1196 local_irq_disable();
1197 device_power_down(PMSG_SUSPEND);
1201 save_processor_state();
1202 err = set_system_power_state(APM_STATE_SUSPEND);
1203 ignore_normal_resume = 1;
1204 restore_processor_state();
1206 local_irq_disable();
1209 if (err == APM_NO_ERROR)
1211 if (err != APM_SUCCESS)
1212 apm_error("suspend", err);
1213 err = (err == APM_SUCCESS) ? 0 : -EIO;
1214 device_power_up(PMSG_RESUME);
1216 device_resume(PMSG_RESUME);
1217 queue_event(APM_NORMAL_RESUME, NULL);
1218 spin_lock(&user_list_lock);
1219 for (as = user_list; as != NULL; as = as->next) {
1220 as->suspend_wait = 0;
1221 as->suspend_result = err;
1223 spin_unlock(&user_list_lock);
1224 wake_up_interruptible(&apm_suspend_waitqueue);
1228 static void standby(void)
1232 local_irq_disable();
1233 device_power_down(PMSG_SUSPEND);
1236 err = set_system_power_state(APM_STATE_STANDBY);
1237 if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1238 apm_error("standby", err);
1240 local_irq_disable();
1241 device_power_up(PMSG_RESUME);
1245 static apm_event_t get_event(void)
1248 apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1249 apm_eventinfo_t info;
1251 static int notified;
1253 /* we don't use the eventinfo */
1254 error = apm_get_event(&event, &info);
1255 if (error == APM_SUCCESS)
1258 if ((error != APM_NO_EVENTS) && (notified++ == 0))
1259 apm_error("get_event", error);
1264 static void check_events(void)
1267 static unsigned long last_resume;
1268 static int ignore_bounce;
1270 while ((event = get_event()) != 0) {
1272 if (event <= NR_APM_EVENT_NAME)
1273 printk(KERN_DEBUG "apm: received %s notify\n",
1274 apm_event_name[event - 1]);
1276 printk(KERN_DEBUG "apm: received unknown "
1277 "event 0x%02x\n", event);
1280 && (time_after(jiffies, last_resume + bounce_interval)))
1284 case APM_SYS_STANDBY:
1285 case APM_USER_STANDBY:
1286 queue_event(event, NULL);
1287 if (standbys_pending <= 0)
1291 case APM_USER_SUSPEND:
1292 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1293 if (apm_info.connection_version > 0x100)
1294 set_system_power_state(APM_STATE_REJECT);
1297 case APM_SYS_SUSPEND:
1298 if (ignore_bounce) {
1299 if (apm_info.connection_version > 0x100)
1300 set_system_power_state(APM_STATE_REJECT);
1304 * If we are already processing a SUSPEND,
1305 * then further SUSPEND events from the BIOS
1306 * will be ignored. We also return here to
1307 * cope with the fact that the Thinkpads keep
1308 * sending a SUSPEND event until something else
1311 if (ignore_sys_suspend)
1313 ignore_sys_suspend = 1;
1314 queue_event(event, NULL);
1315 if (suspends_pending <= 0)
1319 case APM_NORMAL_RESUME:
1320 case APM_CRITICAL_RESUME:
1321 case APM_STANDBY_RESUME:
1322 ignore_sys_suspend = 0;
1323 last_resume = jiffies;
1325 if ((event != APM_NORMAL_RESUME)
1326 || (ignore_normal_resume == 0)) {
1327 device_resume(PMSG_RESUME);
1328 queue_event(event, NULL);
1330 ignore_normal_resume = 0;
1333 case APM_CAPABILITY_CHANGE:
1334 case APM_LOW_BATTERY:
1335 case APM_POWER_STATUS_CHANGE:
1336 queue_event(event, NULL);
1337 /* If needed, notify drivers here */
1340 case APM_UPDATE_TIME:
1343 case APM_CRITICAL_SUSPEND:
1345 * We are not allowed to reject a critical suspend.
1353 static void apm_event_handler(void)
1355 static int pending_count = 4;
1358 if ((standbys_pending > 0) || (suspends_pending > 0)) {
1359 if ((apm_info.connection_version > 0x100) &&
1360 (pending_count-- <= 0)) {
1363 printk(KERN_DEBUG "apm: setting state busy\n");
1364 err = set_system_power_state(APM_STATE_BUSY);
1366 apm_error("busy", err);
1374 * This is the APM thread main loop.
1377 static void apm_mainloop(void)
1379 DECLARE_WAITQUEUE(wait, current);
1381 add_wait_queue(&apm_waitqueue, &wait);
1382 set_current_state(TASK_INTERRUPTIBLE);
1384 schedule_timeout(APM_CHECK_TIMEOUT);
1385 if (kthread_should_stop())
1388 * Ok, check all events, check for idle (and mark us sleeping
1389 * so as not to count towards the load average)..
1391 set_current_state(TASK_INTERRUPTIBLE);
1392 apm_event_handler();
1394 remove_wait_queue(&apm_waitqueue, &wait);
1397 static int check_apm_user(struct apm_user *as, const char *func)
1399 if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1400 printk(KERN_ERR "apm: %s passed bad filp\n", func);
1406 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1408 struct apm_user *as;
1412 as = fp->private_data;
1413 if (check_apm_user(as, "read"))
1415 if ((int)count < sizeof(apm_event_t))
1417 if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1419 wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1421 while ((i >= sizeof(event)) && !queue_empty(as)) {
1422 event = get_queued_event(as);
1423 if (copy_to_user(buf, &event, sizeof(event))) {
1429 case APM_SYS_SUSPEND:
1430 case APM_USER_SUSPEND:
1431 as->suspends_read++;
1434 case APM_SYS_STANDBY:
1435 case APM_USER_STANDBY:
1436 as->standbys_read++;
1439 buf += sizeof(event);
1444 if (signal_pending(current))
1445 return -ERESTARTSYS;
1449 static unsigned int do_poll(struct file *fp, poll_table *wait)
1451 struct apm_user *as;
1453 as = fp->private_data;
1454 if (check_apm_user(as, "poll"))
1456 poll_wait(fp, &apm_waitqueue, wait);
1457 if (!queue_empty(as))
1458 return POLLIN | POLLRDNORM;
1462 static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1464 struct apm_user *as;
1467 as = filp->private_data;
1468 if (check_apm_user(as, "ioctl"))
1470 if (!as->suser || !as->writer)
1473 case APM_IOC_STANDBY:
1475 if (as->standbys_read > 0) {
1476 as->standbys_read--;
1477 as->standbys_pending--;
1480 queue_event(APM_USER_STANDBY, as);
1481 if (standbys_pending <= 0)
1485 case APM_IOC_SUSPEND:
1487 if (as->suspends_read > 0) {
1488 as->suspends_read--;
1489 as->suspends_pending--;
1492 queue_event(APM_USER_SUSPEND, as);
1493 if (suspends_pending <= 0) {
1496 as->suspend_wait = 1;
1497 wait_event_interruptible(apm_suspend_waitqueue,
1498 as->suspend_wait == 0);
1499 ret = as->suspend_result;
1509 static int do_release(struct inode *inode, struct file *filp)
1511 struct apm_user *as;
1513 as = filp->private_data;
1514 if (check_apm_user(as, "release"))
1516 filp->private_data = NULL;
1517 if (as->standbys_pending > 0) {
1518 standbys_pending -= as->standbys_pending;
1519 if (standbys_pending <= 0)
1522 if (as->suspends_pending > 0) {
1523 suspends_pending -= as->suspends_pending;
1524 if (suspends_pending <= 0)
1527 spin_lock(&user_list_lock);
1528 if (user_list == as)
1529 user_list = as->next;
1531 struct apm_user *as1;
1533 for (as1 = user_list;
1534 (as1 != NULL) && (as1->next != as);
1538 printk(KERN_ERR "apm: filp not in user list\n");
1540 as1->next = as->next;
1542 spin_unlock(&user_list_lock);
1547 static int do_open(struct inode *inode, struct file *filp)
1549 struct apm_user *as;
1552 as = kmalloc(sizeof(*as), GFP_KERNEL);
1554 printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
1559 as->magic = APM_BIOS_MAGIC;
1560 as->event_tail = as->event_head = 0;
1561 as->suspends_pending = as->standbys_pending = 0;
1562 as->suspends_read = as->standbys_read = 0;
1564 * XXX - this is a tiny bit broken, when we consider BSD
1565 * process accounting. If the device is opened by root, we
1566 * instantly flag that we used superuser privs. Who knows,
1567 * we might close the device immediately without doing a
1568 * privileged operation -- cevans
1570 as->suser = capable(CAP_SYS_ADMIN);
1571 as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1572 as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1573 spin_lock(&user_list_lock);
1574 as->next = user_list;
1576 spin_unlock(&user_list_lock);
1577 filp->private_data = as;
1582 static int proc_apm_show(struct seq_file *m, void *v)
1588 unsigned short ac_line_status = 0xff;
1589 unsigned short battery_status = 0xff;
1590 unsigned short battery_flag = 0xff;
1591 int percentage = -1;
1592 int time_units = -1;
1595 if ((num_online_cpus() == 1) &&
1596 !(error = apm_get_power_status(&bx, &cx, &dx))) {
1597 ac_line_status = (bx >> 8) & 0xff;
1598 battery_status = bx & 0xff;
1599 if ((cx & 0xff) != 0xff)
1600 percentage = cx & 0xff;
1602 if (apm_info.connection_version > 0x100) {
1603 battery_flag = (cx >> 8) & 0xff;
1605 units = (dx & 0x8000) ? "min" : "sec";
1606 time_units = dx & 0x7fff;
1610 /* Arguments, with symbols from linux/apm_bios.h. Information is
1611 from the Get Power Status (0x0a) call unless otherwise noted.
1613 0) Linux driver version (this will change if format changes)
1614 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2.
1615 2) APM flags from APM Installation Check (0x00):
1616 bit 0: APM_16_BIT_SUPPORT
1617 bit 1: APM_32_BIT_SUPPORT
1618 bit 2: APM_IDLE_SLOWS_CLOCK
1619 bit 3: APM_BIOS_DISABLED
1620 bit 4: APM_BIOS_DISENGAGED
1624 0x02: On backup power (BIOS >= 1.1 only)
1631 0x04: Selected battery not present (BIOS >= 1.2 only)
1638 bit 7: No system battery
1640 6) Remaining battery life (percentage of charge):
1643 7) Remaining battery life (time units):
1644 Number of remaining minutes or seconds
1646 8) min = minutes; sec = seconds */
1648 seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1650 (apm_info.bios.version >> 8) & 0xff,
1651 apm_info.bios.version & 0xff,
1652 apm_info.bios.flags,
1662 static int proc_apm_open(struct inode *inode, struct file *file)
1664 return single_open(file, proc_apm_show, NULL);
1667 static const struct file_operations apm_file_ops = {
1668 .owner = THIS_MODULE,
1669 .open = proc_apm_open,
1671 .llseek = seq_lseek,
1672 .release = single_release,
1675 static int apm(void *unused)
1686 * This is to avoid random crashes at boot time during initialization
1687 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1688 * Some bioses don't like being called from CPU != 0.
1689 * Method suggested by Ingo Molnar.
1691 set_cpus_allowed(current, cpumask_of_cpu(0));
1692 BUG_ON(smp_processor_id() != 0);
1695 if (apm_info.connection_version == 0) {
1696 apm_info.connection_version = apm_info.bios.version;
1697 if (apm_info.connection_version > 0x100) {
1699 * We only support BIOSs up to version 1.2
1701 if (apm_info.connection_version > 0x0102)
1702 apm_info.connection_version = 0x0102;
1703 error = apm_driver_version(&apm_info.connection_version);
1704 if (error != APM_SUCCESS) {
1705 apm_error("driver version", error);
1706 /* Fall back to an APM 1.0 connection. */
1707 apm_info.connection_version = 0x100;
1713 printk(KERN_INFO "apm: Connection version %d.%d\n",
1714 (apm_info.connection_version >> 8) & 0xff,
1715 apm_info.connection_version & 0xff);
1717 #ifdef CONFIG_APM_DO_ENABLE
1718 if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1720 * This call causes my NEC UltraLite Versa 33/C to hang if it
1721 * is booted with PM disabled but not in the docking station.
1724 error = apm_enable_power_management(1);
1726 apm_error("enable power management", error);
1732 if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1733 && (apm_info.connection_version > 0x0100)) {
1734 error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1736 apm_error("engage power management", error);
1741 if (debug && (num_online_cpus() == 1 || smp)) {
1742 error = apm_get_power_status(&bx, &cx, &dx);
1744 printk(KERN_INFO "apm: power status not available\n");
1746 switch ((bx >> 8) & 0xff) {
1748 power_stat = "off line";
1751 power_stat = "on line";
1754 power_stat = "on backup power";
1757 power_stat = "unknown";
1760 switch (bx & 0xff) {
1768 bat_stat = "critical";
1771 bat_stat = "charging";
1774 bat_stat = "unknown";
1778 "apm: AC %s, battery status %s, battery life ",
1779 power_stat, bat_stat);
1780 if ((cx & 0xff) == 0xff)
1781 printk("unknown\n");
1783 printk("%d%%\n", cx & 0xff);
1784 if (apm_info.connection_version > 0x100) {
1786 "apm: battery flag 0x%02x, battery life ",
1789 printk("unknown\n");
1791 printk("%d %s\n", dx & 0x7fff,
1793 "minutes" : "seconds");
1798 /* Install our power off handler.. */
1800 pm_power_off = apm_power_off;
1802 if (num_online_cpus() == 1 || smp) {
1803 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1804 console_blank_hook = apm_console_blank;
1807 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1808 console_blank_hook = NULL;
1816 static int __init apm_setup(char *str)
1820 while ((str != NULL) && (*str != '\0')) {
1821 if (strncmp(str, "off", 3) == 0)
1823 if (strncmp(str, "on", 2) == 0)
1825 if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1826 (strncmp(str, "bounce_interval=", 16) == 0))
1827 bounce_interval = simple_strtol(str + 16, NULL, 0);
1828 if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1829 (strncmp(str, "idle_threshold=", 15) == 0))
1830 idle_threshold = simple_strtol(str + 15, NULL, 0);
1831 if ((strncmp(str, "idle-period=", 12) == 0) ||
1832 (strncmp(str, "idle_period=", 12) == 0))
1833 idle_period = simple_strtol(str + 12, NULL, 0);
1834 invert = (strncmp(str, "no-", 3) == 0) ||
1835 (strncmp(str, "no_", 3) == 0);
1838 if (strncmp(str, "debug", 5) == 0)
1840 if ((strncmp(str, "power-off", 9) == 0) ||
1841 (strncmp(str, "power_off", 9) == 0))
1842 power_off = !invert;
1843 if (strncmp(str, "smp", 3) == 0) {
1845 idle_threshold = 100;
1847 if ((strncmp(str, "allow-ints", 10) == 0) ||
1848 (strncmp(str, "allow_ints", 10) == 0))
1849 apm_info.allow_ints = !invert;
1850 if ((strncmp(str, "broken-psr", 10) == 0) ||
1851 (strncmp(str, "broken_psr", 10) == 0))
1852 apm_info.get_power_status_broken = !invert;
1853 if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1854 (strncmp(str, "realmode_power_off", 18) == 0))
1855 apm_info.realmode_power_off = !invert;
1856 str = strchr(str, ',');
1858 str += strspn(str, ", \t");
1863 __setup("apm=", apm_setup);
1866 static const struct file_operations apm_bios_fops = {
1867 .owner = THIS_MODULE,
1870 .unlocked_ioctl = do_ioctl,
1872 .release = do_release,
1875 static struct miscdevice apm_device = {
1882 /* Simple "print if true" callback */
1883 static int __init print_if_true(const struct dmi_system_id *d)
1885 printk("%s\n", d->ident);
1890 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1891 * disabled before the suspend. Linux used to get terribly confused by that.
1893 static int __init broken_ps2_resume(const struct dmi_system_id *d)
1895 printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1896 "workaround hopefully not needed.\n", d->ident);
1900 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1901 static int __init set_realmode_power_off(const struct dmi_system_id *d)
1903 if (apm_info.realmode_power_off == 0) {
1904 apm_info.realmode_power_off = 1;
1905 printk(KERN_INFO "%s bios detected. "
1906 "Using realmode poweroff only.\n", d->ident);
1911 /* Some laptops require interrupts to be enabled during APM calls */
1912 static int __init set_apm_ints(const struct dmi_system_id *d)
1914 if (apm_info.allow_ints == 0) {
1915 apm_info.allow_ints = 1;
1916 printk(KERN_INFO "%s machine detected. "
1917 "Enabling interrupts during APM calls.\n", d->ident);
1922 /* Some APM bioses corrupt memory or just plain do not work */
1923 static int __init apm_is_horked(const struct dmi_system_id *d)
1925 if (apm_info.disabled == 0) {
1926 apm_info.disabled = 1;
1927 printk(KERN_INFO "%s machine detected. "
1928 "Disabling APM.\n", d->ident);
1933 static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1935 if (apm_info.disabled == 0) {
1936 apm_info.disabled = 1;
1937 printk(KERN_INFO "%s machine detected. "
1938 "Disabling APM.\n", d->ident);
1939 printk(KERN_INFO "This bug is fixed in bios P15 which is available for \n");
1940 printk(KERN_INFO "download from support.intel.com \n");
1945 /* Some APM bioses hang on APM idle calls */
1946 static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1948 if (apm_info.forbid_idle == 0) {
1949 apm_info.forbid_idle = 1;
1950 printk(KERN_INFO "%s machine detected. "
1951 "Disabling APM idle calls.\n", d->ident);
1957 * Check for clue free BIOS implementations who use
1958 * the following QA technique
1960 * [ Write BIOS Code ]<------
1962 * < Does it Compile >----N--
1964 * < Does it Boot Win98 >-N--
1968 * Phoenix A04 08/24/2000 is known bad (Dell Inspiron 5000e)
1969 * Phoenix A07 09/29/2000 is known good (Dell Inspiron 5000)
1971 static int __init broken_apm_power(const struct dmi_system_id *d)
1973 apm_info.get_power_status_broken = 1;
1974 printk(KERN_WARNING "BIOS strings suggest APM bugs, "
1975 "disabling power status reporting.\n");
1980 * This bios swaps the APM minute reporting bytes over (Many sony laptops
1981 * have this problem).
1983 static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
1985 apm_info.get_power_status_swabinminutes = 1;
1986 printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
1987 "in minutes and wrong byte order.\n");
1991 static struct dmi_system_id __initdata apm_dmi_table[] = {
1994 KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
1995 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
1996 DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
1998 { /* Handle problems with APM on the C600 */
1999 broken_ps2_resume, "Dell Latitude C600",
2000 { DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2001 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2003 { /* Allow interrupts during suspend on Dell Latitude laptops*/
2004 set_apm_ints, "Dell Latitude",
2005 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2006 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2009 apm_is_horked, "Dell Inspiron 2500",
2010 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2011 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2012 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2013 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2015 { /* Allow interrupts during suspend on Dell Inspiron laptops*/
2016 set_apm_ints, "Dell Inspiron", {
2017 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2018 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2020 { /* Handle problems with APM on Inspiron 5000e */
2021 broken_apm_power, "Dell Inspiron 5000e",
2022 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2023 DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2024 DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2026 { /* Handle problems with APM on Inspiron 2500 */
2027 broken_apm_power, "Dell Inspiron 2500",
2028 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2029 DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2030 DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2033 apm_is_horked, "Dell Dimension 4100",
2034 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2035 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2036 DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2037 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2039 { /* Allow interrupts during suspend on Compaq Laptops*/
2040 set_apm_ints, "Compaq 12XL125",
2041 { DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2042 DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2043 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2044 DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2046 { /* Allow interrupts during APM or the clock goes slow */
2047 set_apm_ints, "ASUSTeK",
2048 { DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2049 DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2051 { /* APM blows on shutdown */
2052 apm_is_horked, "ABIT KX7-333[R]",
2053 { DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2054 DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2057 apm_is_horked, "Trigem Delhi3",
2058 { DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2059 DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2062 apm_is_horked, "Fujitsu-Siemens",
2063 { DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2064 DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2067 apm_is_horked_d850md, "Intel D850MD",
2068 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2069 DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2072 apm_is_horked, "Intel D810EMO",
2073 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2074 DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2077 apm_is_horked, "Dell XPS-Z",
2078 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2079 DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2080 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2083 apm_is_horked, "Sharp PC-PJ/AX",
2084 { DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2085 DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2086 DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2087 DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2090 apm_is_horked, "Dell Inspiron 2500",
2091 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2092 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2093 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2094 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2096 { /* APM idle hangs */
2097 apm_likes_to_melt, "Jabil AMD",
2098 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2099 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2101 { /* APM idle hangs */
2102 apm_likes_to_melt, "AMI Bios",
2103 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2104 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2106 { /* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2107 swab_apm_power_in_minutes, "Sony VAIO",
2108 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2109 DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2110 DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2112 { /* Handle problems with APM on Sony Vaio PCG-N505VX */
2113 swab_apm_power_in_minutes, "Sony VAIO",
2114 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2115 DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2116 DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2118 { /* Handle problems with APM on Sony Vaio PCG-XG29 */
2119 swab_apm_power_in_minutes, "Sony VAIO",
2120 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2121 DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2122 DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2124 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2125 swab_apm_power_in_minutes, "Sony VAIO",
2126 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2127 DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2128 DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2130 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2131 swab_apm_power_in_minutes, "Sony VAIO",
2132 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2133 DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2134 DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2136 { /* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2137 swab_apm_power_in_minutes, "Sony VAIO",
2138 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2139 DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2140 DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2142 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2143 swab_apm_power_in_minutes, "Sony VAIO",
2144 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2145 DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2146 DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2148 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2149 swab_apm_power_in_minutes, "Sony VAIO",
2150 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2151 DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2152 DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2154 { /* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2155 swab_apm_power_in_minutes, "Sony VAIO",
2156 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2157 DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2158 DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2160 { /* Handle problems with APM on Sony Vaio PCG-F104K */
2161 swab_apm_power_in_minutes, "Sony VAIO",
2162 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2163 DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2164 DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2167 { /* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2168 swab_apm_power_in_minutes, "Sony VAIO",
2169 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2170 DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2171 DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2173 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2174 swab_apm_power_in_minutes, "Sony VAIO",
2175 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2176 DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2177 DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2179 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2180 swab_apm_power_in_minutes, "Sony VAIO",
2181 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2182 DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2183 DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2185 { /* broken PM poweroff bios */
2186 set_realmode_power_off, "Award Software v4.60 PGMA",
2187 { DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2188 DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2189 DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2192 /* Generic per vendor APM settings */
2194 { /* Allow interrupts during suspend on IBM laptops */
2195 set_apm_ints, "IBM",
2196 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2203 * Just start the APM thread. We do NOT want to do APM BIOS
2204 * calls from anything but the APM thread, if for no other reason
2205 * than the fact that we don't trust the APM BIOS. This way,
2206 * most common APM BIOS problems that lead to protection errors
2207 * etc will have at least some level of being contained...
2209 * In short, if something bad happens, at least we have a choice
2210 * of just killing the apm thread..
2212 static int __init apm_init(void)
2214 struct desc_struct *gdt;
2217 dmi_check_system(apm_dmi_table);
2219 if (apm_info.bios.version == 0 || paravirt_enabled()) {
2220 printk(KERN_INFO "apm: BIOS not found.\n");
2224 "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2225 ((apm_info.bios.version >> 8) & 0xff),
2226 (apm_info.bios.version & 0xff),
2227 apm_info.bios.flags,
2229 if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2230 printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2235 apm_info.allow_ints = 1;
2237 apm_info.get_power_status_broken = 1;
2238 if (realmode_power_off)
2239 apm_info.realmode_power_off = 1;
2240 /* User can override, but default is to trust DMI */
2241 if (apm_disabled != -1)
2242 apm_info.disabled = apm_disabled;
2245 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2246 * but is reportedly a 1.0 BIOS.
2248 if (apm_info.bios.version == 0x001)
2249 apm_info.bios.version = 0x100;
2251 /* BIOS < 1.2 doesn't set cseg_16_len */
2252 if (apm_info.bios.version < 0x102)
2253 apm_info.bios.cseg_16_len = 0; /* 64k */
2256 printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2257 apm_info.bios.cseg, apm_info.bios.offset,
2258 apm_info.bios.cseg_16, apm_info.bios.dseg);
2259 if (apm_info.bios.version > 0x100)
2260 printk(" cseg len %x, dseg len %x",
2261 apm_info.bios.cseg_len,
2262 apm_info.bios.dseg_len);
2263 if (apm_info.bios.version > 0x101)
2264 printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2268 if (apm_info.disabled) {
2269 printk(KERN_NOTICE "apm: disabled on user request.\n");
2272 if ((num_online_cpus() > 1) && !power_off && !smp) {
2273 printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
2274 apm_info.disabled = 1;
2277 if (pm_flags & PM_ACPI) {
2278 printk(KERN_NOTICE "apm: overridden by ACPI.\n");
2279 apm_info.disabled = 1;
2285 * Set up a segment that references the real mode segment 0x40
2286 * that extends up to the end of page zero (that we have reserved).
2287 * This is for buggy BIOS's that refer to (real mode) segment 0x40
2288 * even though they are called in protected mode.
2290 set_base(bad_bios_desc, __va((unsigned long)0x40 << 4));
2291 _set_limit((char *)&bad_bios_desc, 4095 - (0x40 << 4));
2294 * Set up the long jump entry point to the APM BIOS, which is called
2295 * from inline assembly.
2297 apm_bios_entry.offset = apm_info.bios.offset;
2298 apm_bios_entry.segment = APM_CS;
2301 * The APM 1.1 BIOS is supposed to provide limit information that it
2302 * recognizes. Many machines do this correctly, but many others do
2303 * not restrict themselves to their claimed limit. When this happens,
2304 * they will cause a segmentation violation in the kernel at boot time.
2305 * Most BIOS's, however, will respect a 64k limit, so we use that.
2307 * Note we only set APM segments on CPU zero, since we pin the APM
2310 gdt = get_cpu_gdt_table(0);
2311 set_base(gdt[APM_CS >> 3],
2312 __va((unsigned long)apm_info.bios.cseg << 4));
2313 set_base(gdt[APM_CS_16 >> 3],
2314 __va((unsigned long)apm_info.bios.cseg_16 << 4));
2315 set_base(gdt[APM_DS >> 3],
2316 __va((unsigned long)apm_info.bios.dseg << 4));
2318 proc_create("apm", 0, NULL, &apm_file_ops);
2320 kapmd_task = kthread_create(apm, NULL, "kapmd");
2321 if (IS_ERR(kapmd_task)) {
2322 printk(KERN_ERR "apm: disabled - Unable to start kernel "
2324 err = PTR_ERR(kapmd_task);
2326 remove_proc_entry("apm", NULL);
2329 wake_up_process(kapmd_task);
2331 if (num_online_cpus() > 1 && !smp) {
2333 "apm: disabled - APM is not SMP safe (power off active).\n");
2338 * Note we don't actually care if the misc_device cannot be registered.
2339 * this driver can do its job without it, even if userspace can't
2340 * control it. just log the error
2342 if (misc_register(&apm_device))
2343 printk(KERN_WARNING "apm: Could not register misc device.\n");
2346 idle_period = (idle_period * HZ) / 100;
2347 if (idle_threshold < 100) {
2348 original_pm_idle = pm_idle;
2349 pm_idle = apm_cpu_idle;
2356 static void __exit apm_exit(void)
2361 pm_idle = original_pm_idle;
2363 * We are about to unload the current idle thread pm callback
2364 * (pm_idle), Wait for all processors to update cached/local
2365 * copies of pm_idle before proceeding.
2369 if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2370 && (apm_info.connection_version > 0x0100)) {
2371 error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2373 apm_error("disengage power management", error);
2375 misc_deregister(&apm_device);
2376 remove_proc_entry("apm", NULL);
2378 pm_power_off = NULL;
2380 kthread_stop(kapmd_task);
2383 pm_flags &= ~PM_APM;
2386 module_init(apm_init);
2387 module_exit(apm_exit);
2389 MODULE_AUTHOR("Stephen Rothwell");
2390 MODULE_DESCRIPTION("Advanced Power Management");
2391 MODULE_LICENSE("GPL");
2392 module_param(debug, bool, 0644);
2393 MODULE_PARM_DESC(debug, "Enable debug mode");
2394 module_param(power_off, bool, 0444);
2395 MODULE_PARM_DESC(power_off, "Enable power off");
2396 module_param(bounce_interval, int, 0444);
2397 MODULE_PARM_DESC(bounce_interval,
2398 "Set the number of ticks to ignore suspend bounces");
2399 module_param(allow_ints, bool, 0444);
2400 MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2401 module_param(broken_psr, bool, 0444);
2402 MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2403 module_param(realmode_power_off, bool, 0444);
2404 MODULE_PARM_DESC(realmode_power_off,
2405 "Switch to real mode before powering off");
2406 module_param(idle_threshold, int, 0444);
2407 MODULE_PARM_DESC(idle_threshold,
2408 "System idle percentage above which to make APM BIOS idle calls");
2409 module_param(idle_period, int, 0444);
2410 MODULE_PARM_DESC(idle_period,
2411 "Period (in sec/100) over which to caculate the idle percentage");
2412 module_param(smp, bool, 0444);
2413 MODULE_PARM_DESC(smp,
2414 "Set this to enable APM use on an SMP platform. Use with caution on older systems");
2415 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);