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 replacment 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 <jdthood@mail.com>)
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 <jdthood@mail.com>)
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/hwdev/busbios/amp_12.htm]
204 #include <linux/config.h>
205 #include <linux/module.h>
207 #include <linux/poll.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/miscdevice.h>
216 #include <linux/apm_bios.h>
217 #include <linux/init.h>
218 #include <linux/time.h>
219 #include <linux/sched.h>
220 #include <linux/pm.h>
221 #include <linux/device.h>
222 #include <linux/kernel.h>
223 #include <linux/smp.h>
224 #include <linux/smp_lock.h>
226 #include <asm/system.h>
227 #include <asm/uaccess.h>
228 #include <asm/desc.h>
229 #include <asm/suspend.h>
231 #include "io_ports.h"
233 extern spinlock_t i8253_lock;
234 extern unsigned long get_cmos_time(void);
235 extern void machine_real_restart(unsigned char *, int);
237 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
238 extern int (*console_blank_hook)(int);
242 * The apm_bios device is one of the misc char devices.
243 * This is its minor number.
245 #define APM_MINOR_DEV 134
248 * See Documentation/Config.help for the configuration options.
250 * Various options can be changed at boot time as follows:
251 * (We allow underscores for compatibility with the modules code)
252 * apm=on/off enable/disable APM
253 * [no-]allow[-_]ints allow interrupts during BIOS calls
254 * [no-]broken[-_]psr BIOS has a broken GetPowerStatus call
255 * [no-]realmode[-_]power[-_]off switch to real mode before
257 * [no-]debug log some debugging messages
258 * [no-]power[-_]off power off on shutdown
259 * [no-]smp Use apm even on an SMP box
260 * bounce[-_]interval=<n> number of ticks to ignore suspend
262 * idle[-_]threshold=<n> System idle percentage above which to
263 * make APM BIOS idle calls. Set it to
265 * idle[-_]period=<n> Period (in 1/100s of a second) over
266 * which the idle percentage is
270 /* KNOWN PROBLEM MACHINES:
272 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
273 * [Confirmed by TI representative]
274 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
275 * [Confirmed by BIOS disassembly]
276 * [This may work now ...]
277 * P: Toshiba 1950S: battery life information only gets updated after resume
278 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
279 * broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
280 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
281 * Neale Banks <neale@lowendale.com.au> December 2000
283 * Legend: U = unusable with APM patches
284 * P = partially usable with APM patches
288 * Define as 1 to make the driver always call the APM BIOS busy
289 * routine even if the clock was not reported as slowed by the
290 * idle routine. Otherwise, define as 0.
292 #define ALWAYS_CALL_BUSY 1
295 * Define to make the APM BIOS calls zero all data segment registers (so
296 * that an incorrect BIOS implementation will cause a kernel panic if it
297 * tries to write to arbitrary memory).
299 #define APM_ZERO_SEGS
304 * Define to make all _set_limit calls use 64k limits. The APM 1.1 BIOS is
305 * supposed to provide limit information that it recognizes. Many machines
306 * do this correctly, but many others do not restrict themselves to their
307 * claimed limit. When this happens, they will cause a segmentation
308 * violation in the kernel at boot time. Most BIOS's, however, will
309 * respect a 64k limit, so we use that. If you want to be pedantic and
310 * hold your BIOS to its claims, then undefine this.
312 #define APM_RELAX_SEGMENTS
315 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
316 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
317 * David Chen <chen@ctpa04.mit.edu>
319 #undef INIT_TIMER_AFTER_SUSPEND
321 #ifdef INIT_TIMER_AFTER_SUSPEND
322 #include <linux/timex.h>
324 #include <linux/delay.h>
328 * Need to poll the APM BIOS every second
330 #define APM_CHECK_TIMEOUT (HZ)
333 * Ignore suspend events for this amount of time after a resume
335 #define DEFAULT_BOUNCE_INTERVAL (3 * HZ)
338 * Maximum number of events stored
340 #define APM_MAX_EVENTS 20
343 * The per-file APM data
347 struct apm_user * next;
353 int suspends_pending;
354 int standbys_pending;
359 apm_event_t events[APM_MAX_EVENTS];
363 * The magic number in apm_user
365 #define APM_BIOS_MAGIC 0x4101
368 * idle percentage above which bios idle calls are done
370 #ifdef CONFIG_APM_CPU_IDLE
371 #define DEFAULT_IDLE_THRESHOLD 95
373 #define DEFAULT_IDLE_THRESHOLD 100
375 #define DEFAULT_IDLE_PERIOD (100 / 3)
381 unsigned long offset;
382 unsigned short segment;
384 static int clock_slowed;
385 static int idle_threshold = DEFAULT_IDLE_THRESHOLD;
386 static int idle_period = DEFAULT_IDLE_PERIOD;
387 static int set_pm_idle;
388 static int suspends_pending;
389 static int standbys_pending;
390 static int ignore_sys_suspend;
391 static int ignore_normal_resume;
392 static int bounce_interval = DEFAULT_BOUNCE_INTERVAL;
394 #ifdef CONFIG_APM_RTC_IS_GMT
395 # define clock_cmos_diff 0
396 # define got_clock_diff 1
398 static long clock_cmos_diff;
399 static int got_clock_diff;
403 static int apm_disabled = -1;
405 static int power_off;
407 static int power_off = 1;
409 #ifdef CONFIG_APM_REAL_MODE_POWER_OFF
410 static int realmode_power_off = 1;
412 static int realmode_power_off;
414 static int exit_kapmd;
415 static int kapmd_running;
416 #ifdef CONFIG_APM_ALLOW_INTS
417 static int allow_ints = 1;
419 static int allow_ints;
421 static int broken_psr;
423 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
424 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
425 static struct apm_user * user_list;
426 static spinlock_t user_list_lock = SPIN_LOCK_UNLOCKED;
427 static struct desc_struct bad_bios_desc = { 0, 0x00409200 };
429 static char driver_version[] = "1.16ac"; /* no spaces */
432 * APM event names taken from the APM 1.2 specification. These are
433 * the message codes that the BIOS uses to tell us about events
435 static char * apm_event_name[] = {
441 "power status change",
446 "system standby resume",
447 "capabilities change"
449 #define NR_APM_EVENT_NAME \
450 (sizeof(apm_event_name) / sizeof(apm_event_name[0]))
452 typedef struct lookup_t {
458 * The BIOS returns a set of standard error codes in AX when the
462 static const lookup_t error_table[] = {
463 /* N/A { APM_SUCCESS, "Operation succeeded" }, */
464 { APM_DISABLED, "Power management disabled" },
465 { APM_CONNECTED, "Real mode interface already connected" },
466 { APM_NOT_CONNECTED, "Interface not connected" },
467 { APM_16_CONNECTED, "16 bit interface already connected" },
468 /* N/A { APM_16_UNSUPPORTED, "16 bit interface not supported" }, */
469 { APM_32_CONNECTED, "32 bit interface already connected" },
470 { APM_32_UNSUPPORTED, "32 bit interface not supported" },
471 { APM_BAD_DEVICE, "Unrecognized device ID" },
472 { APM_BAD_PARAM, "Parameter out of range" },
473 { APM_NOT_ENGAGED, "Interface not engaged" },
474 { APM_BAD_FUNCTION, "Function not supported" },
475 { APM_RESUME_DISABLED, "Resume timer disabled" },
476 { APM_BAD_STATE, "Unable to enter requested state" },
477 /* N/A { APM_NO_EVENTS, "No events pending" }, */
478 { APM_NO_ERROR, "BIOS did not set a return code" },
479 { APM_NOT_PRESENT, "No APM present" }
481 #define ERROR_COUNT (sizeof(error_table)/sizeof(lookup_t))
484 * apm_error - display an APM error
485 * @str: information string
486 * @err: APM BIOS return code
488 * Write a meaningful log entry to the kernel log in the event of
492 static void apm_error(char *str, int err)
496 for (i = 0; i < ERROR_COUNT; i++)
497 if (error_table[i].key == err) break;
499 printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg);
501 printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n",
506 * Lock APM functionality to physical CPU 0
511 static cpumask_t apm_save_cpus(void)
513 cpumask_t x = current->cpus_allowed;
514 /* Some bioses don't like being called from CPU != 0 */
515 set_cpus_allowed(current, cpumask_of_cpu(0));
516 BUG_ON(smp_processor_id() != 0);
520 static inline void apm_restore_cpus(cpumask_t mask)
522 set_cpus_allowed(current, mask);
528 * No CPU lockdown needed on a uniprocessor
531 #define apm_save_cpus() (current->cpus_allowed)
532 #define apm_restore_cpus(x) (void)(x)
537 * These are the actual BIOS calls. Depending on APM_ZERO_SEGS and
538 * apm_info.allow_ints, we are being really paranoid here! Not only
539 * are interrupts disabled, but all the segment registers (except SS)
540 * are saved and zeroed this means that if the BIOS tries to reference
541 * any data without explicitly loading the segment registers, the kernel
542 * will fault immediately rather than have some unforeseen circumstances
543 * for the rest of the kernel. And it will be very obvious! :-) Doing
544 * this depends on CS referring to the same physical memory as DS so that
545 * DS can be zeroed before the call. Unfortunately, we can't do anything
546 * about the stack segment/pointer. Also, we tell the compiler that
547 * everything could change.
549 * Also, we KNOW that for the non error case of apm_bios_call, there
550 * is no useful data returned in the low order 8 bits of eax.
553 if (apm_info.allow_ints) \
554 local_irq_enable(); \
559 # define APM_DECL_SEGS \
560 unsigned int saved_fs; unsigned int saved_gs;
561 # define APM_DO_SAVE_SEGS \
562 savesegment(fs, saved_fs); savesegment(gs, saved_gs)
563 # define APM_DO_RESTORE_SEGS \
564 loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
566 # define APM_DECL_SEGS
567 # define APM_DO_SAVE_SEGS
568 # define APM_DO_RESTORE_SEGS
572 * apm_bios_call - Make an APM BIOS 32bit call
573 * @func: APM function to execute
574 * @ebx_in: EBX register for call entry
575 * @ecx_in: ECX register for call entry
576 * @eax: EAX register return
577 * @ebx: EBX register return
578 * @ecx: ECX register return
579 * @edx: EDX register return
580 * @esi: ESI register return
582 * Make an APM call using the 32bit protected mode interface. The
583 * caller is responsible for knowing if APM BIOS is configured and
584 * enabled. This call can disable interrupts for a long period of
585 * time on some laptops. The return value is in AH and the carry
586 * flag is loaded into AL. If there is an error, then the error
587 * code is returned in AH (bits 8-15 of eax) and this function
591 static u8 apm_bios_call(u32 func, u32 ebx_in, u32 ecx_in,
592 u32 *eax, u32 *ebx, u32 *ecx, u32 *edx, u32 *esi)
598 struct desc_struct save_desc_40;
600 cpus = apm_save_cpus();
603 save_desc_40 = cpu_gdt_table[cpu][0x40 / 8];
604 cpu_gdt_table[cpu][0x40 / 8] = bad_bios_desc;
606 local_save_flags(flags);
609 apm_bios_call_asm(func, ebx_in, ecx_in, eax, ebx, ecx, edx, esi);
611 local_irq_restore(flags);
612 cpu_gdt_table[cpu][0x40 / 8] = save_desc_40;
614 apm_restore_cpus(cpus);
620 * apm_bios_call_simple - make a simple APM BIOS 32bit call
621 * @func: APM function to invoke
622 * @ebx_in: EBX register value for BIOS call
623 * @ecx_in: ECX register value for BIOS call
624 * @eax: EAX register on return from the BIOS call
626 * Make a BIOS call that does only returns one value, or just status.
627 * If there is an error, then the error code is returned in AH
628 * (bits 8-15 of eax) and this function returns non-zero. This is
629 * used for simpler BIOS operations. This call may hold interrupts
630 * off for a long time on some laptops.
633 static u8 apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax)
640 struct desc_struct save_desc_40;
643 cpus = apm_save_cpus();
646 save_desc_40 = cpu_gdt_table[cpu][0x40 / 8];
647 cpu_gdt_table[cpu][0x40 / 8] = bad_bios_desc;
649 local_save_flags(flags);
652 error = apm_bios_call_simple_asm(func, ebx_in, ecx_in, eax);
654 local_irq_restore(flags);
655 cpu_gdt_table[smp_processor_id()][0x40 / 8] = save_desc_40;
657 apm_restore_cpus(cpus);
662 * apm_driver_version - APM driver version
663 * @val: loaded with the APM version on return
665 * Retrieve the APM version supported by the BIOS. This is only
666 * supported for APM 1.1 or higher. An error indicates APM 1.0 is
669 * On entry val should point to a value indicating the APM driver
670 * version with the high byte being the major and the low byte the
671 * minor number both in BCD
673 * On return it will hold the BIOS revision supported in the
677 static int apm_driver_version(u_short *val)
681 if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax))
682 return (eax >> 8) & 0xff;
688 * apm_get_event - get an APM event from the BIOS
689 * @event: pointer to the event
690 * @info: point to the event information
692 * The APM BIOS provides a polled information for event
693 * reporting. The BIOS expects to be polled at least every second
694 * when events are pending. When a message is found the caller should
695 * poll until no more messages are present. However, this causes
696 * problems on some laptops where a suspend event notification is
697 * not cleared until it is acknowledged.
699 * Additional information is returned in the info pointer, providing
700 * that APM 1.2 is in use. If no messges are pending the value 0x80
701 * is returned (No power management events pending).
704 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
711 if (apm_bios_call(APM_FUNC_GET_EVENT, 0, 0, &eax, &ebx, &ecx,
713 return (eax >> 8) & 0xff;
715 if (apm_info.connection_version < 0x0102)
716 *info = ~0; /* indicate info not valid */
723 * set_power_state - set the power management state
724 * @what: which items to transition
725 * @state: state to transition to
727 * Request an APM change of state for one or more system devices. The
728 * processor state must be transitioned last of all. what holds the
729 * class of device in the upper byte and the device number (0xFF for
730 * all) for the object to be transitioned.
732 * The state holds the state to transition to, which may in fact
733 * be an acceptance of a BIOS requested state change.
736 static int set_power_state(u_short what, u_short state)
740 if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax))
741 return (eax >> 8) & 0xff;
746 * set_system_power_state - set system wide power state
747 * @state: which state to enter
749 * Transition the entire system into a new APM power state.
752 static int set_system_power_state(u_short state)
754 return set_power_state(APM_DEVICE_ALL, state);
758 * apm_do_idle - perform power saving
760 * This function notifies the BIOS that the processor is (in the view
761 * of the OS) idle. It returns -1 in the event that the BIOS refuses
762 * to handle the idle request. On a success the function returns 1
763 * if the BIOS did clock slowing or 0 otherwise.
766 static int apm_do_idle(void)
770 if (apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax)) {
771 static unsigned long t;
773 /* This always fails on some SMP boards running UP kernels.
774 * Only report the failure the first 5 times.
778 printk(KERN_DEBUG "apm_do_idle failed (%d)\n",
784 clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
789 * apm_do_busy - inform the BIOS the CPU is busy
791 * Request that the BIOS brings the CPU back to full performance.
794 static void apm_do_busy(void)
798 if (clock_slowed || ALWAYS_CALL_BUSY) {
799 (void) apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy);
805 * If no process has really been interested in
806 * the CPU for some time, we want to call BIOS
807 * power management - we probably want
810 #define IDLE_CALC_LIMIT (HZ * 100)
811 #define IDLE_LEAKY_MAX 16
813 static void (*original_pm_idle)(void);
815 extern void default_idle(void);
818 * apm_cpu_idle - cpu idling for APM capable Linux
820 * This is the idling function the kernel executes when APM is available. It
821 * tries to do BIOS powermanagement based on the average system idle time.
822 * Furthermore it calls the system default idle routine.
825 static void apm_cpu_idle(void)
827 static int use_apm_idle; /* = 0 */
828 static unsigned int last_jiffies; /* = 0 */
829 static unsigned int last_stime; /* = 0 */
831 int apm_idle_done = 0;
832 unsigned int jiffies_since_last_check = jiffies - last_jiffies;
836 if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
838 last_jiffies = jiffies;
839 last_stime = current->stime;
840 } else if (jiffies_since_last_check > idle_period) {
841 unsigned int idle_percentage;
843 idle_percentage = current->stime - last_stime;
844 idle_percentage *= 100;
845 idle_percentage /= jiffies_since_last_check;
846 use_apm_idle = (idle_percentage > idle_threshold);
847 if (apm_info.forbid_idle)
849 last_jiffies = jiffies;
850 last_stime = current->stime;
853 bucket = IDLE_LEAKY_MAX;
855 while (!need_resched()) {
860 switch (apm_do_idle()) {
861 case 0: apm_idle_done = 1;
864 bucket = IDLE_LEAKY_MAX;
872 case 1: apm_idle_done = 1;
874 default: /* BIOS refused */
878 if (original_pm_idle)
882 jiffies_since_last_check = jiffies - last_jiffies;
883 if (jiffies_since_last_check > idle_period)
892 * apm_power_off - ask the BIOS to power off
894 * Handle the power off sequence. This is the one piece of code we
895 * will execute even on SMP machines. In order to deal with BIOS
896 * bugs we support real mode APM BIOS power off calls. We also make
897 * the SMP call on CPU0 as some systems will only honour this call
898 * on their first cpu.
901 static void apm_power_off(void)
903 unsigned char po_bios_call[] = {
904 0xb8, 0x00, 0x10, /* movw $0x1000,ax */
905 0x8e, 0xd0, /* movw ax,ss */
906 0xbc, 0x00, 0xf0, /* movw $0xf000,sp */
907 0xb8, 0x07, 0x53, /* movw $0x5307,ax */
908 0xbb, 0x01, 0x00, /* movw $0x0001,bx */
909 0xb9, 0x03, 0x00, /* movw $0x0003,cx */
910 0xcd, 0x15 /* int $0x15 */
914 * This may be called on an SMP machine.
917 /* Some bioses don't like being called from CPU != 0 */
918 set_cpus_allowed(current, cpumask_of_cpu(0));
919 BUG_ON(smp_processor_id() != 0);
921 if (apm_info.realmode_power_off)
923 (void)apm_save_cpus();
924 machine_real_restart(po_bios_call, sizeof(po_bios_call));
927 (void) set_system_power_state(APM_STATE_OFF);
930 #ifdef CONFIG_APM_DO_ENABLE
933 * apm_enable_power_management - enable BIOS APM power management
934 * @enable: enable yes/no
936 * Enable or disable the APM BIOS power services.
939 static int apm_enable_power_management(int enable)
943 if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
944 return APM_NOT_ENGAGED;
945 if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
947 return (eax >> 8) & 0xff;
949 apm_info.bios.flags &= ~APM_BIOS_DISABLED;
951 apm_info.bios.flags |= APM_BIOS_DISABLED;
957 * apm_get_power_status - get current power state
958 * @status: returned status
960 * @life: estimated life
962 * Obtain the current power status from the APM BIOS. We return a
963 * status which gives the rough battery status, and current power
964 * source. The bat value returned give an estimate as a percentage
965 * of life and a status value for the battery. The estimated life
966 * if reported is a lifetime in secodnds/minutes at current powwer
970 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
978 if (apm_info.get_power_status_broken)
979 return APM_32_UNSUPPORTED;
980 if (apm_bios_call(APM_FUNC_GET_STATUS, APM_DEVICE_ALL, 0,
981 &eax, &ebx, &ecx, &edx, &dummy))
982 return (eax >> 8) & 0xff;
985 if (apm_info.get_power_status_swabinminutes) {
986 *life = swab16((u16)edx);
994 static int apm_get_battery_status(u_short which, u_short *status,
995 u_short *bat, u_short *life, u_short *nbat)
1003 if (apm_info.connection_version < 0x0102) {
1004 /* pretend we only have one battery. */
1006 return APM_BAD_DEVICE;
1008 return apm_get_power_status(status, bat, life);
1011 if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1012 &ebx, &ecx, &edx, &esi))
1013 return (eax >> 8) & 0xff;
1023 * apm_engage_power_management - enable PM on a device
1024 * @device: identity of device
1027 * Activate or deactive power management on either a specific device
1028 * or the entire system (%APM_DEVICE_ALL).
1031 static int apm_engage_power_management(u_short device, int enable)
1035 if ((enable == 0) && (device == APM_DEVICE_ALL)
1036 && (apm_info.bios.flags & APM_BIOS_DISABLED))
1037 return APM_DISABLED;
1038 if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable, &eax))
1039 return (eax >> 8) & 0xff;
1040 if (device == APM_DEVICE_ALL) {
1042 apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1044 apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1049 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1052 * apm_console_blank - blank the display
1055 * Attempt to blank the console, firstly by blanking just video device
1056 * zero, and if that fails (some BIOSes don't support it) then it blanks
1057 * all video devices. Typically the BIOS will do laptop backlight and
1058 * monitor powerdown for us.
1061 static int apm_console_blank(int blank)
1066 state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1067 /* Blank the first display device */
1068 error = set_power_state(0x100, state);
1069 if ((error != APM_SUCCESS) && (error != APM_NO_ERROR)) {
1070 /* try to blank them all instead */
1071 error = set_power_state(0x1ff, state);
1072 if ((error != APM_SUCCESS) && (error != APM_NO_ERROR))
1073 /* try to blank device one instead */
1074 error = set_power_state(0x101, state);
1076 if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1078 if (error == APM_NOT_ENGAGED) {
1082 eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1084 apm_error("set display", error);
1085 apm_error("engage interface", eng_error);
1088 return apm_console_blank(blank);
1091 apm_error("set display", error);
1096 static int queue_empty(struct apm_user *as)
1098 return as->event_head == as->event_tail;
1101 static apm_event_t get_queued_event(struct apm_user *as)
1103 as->event_tail = (as->event_tail + 1) % APM_MAX_EVENTS;
1104 return as->events[as->event_tail];
1107 static void queue_event(apm_event_t event, struct apm_user *sender)
1109 struct apm_user * as;
1111 spin_lock(&user_list_lock);
1112 if (user_list == NULL)
1114 for (as = user_list; as != NULL; as = as->next) {
1115 if ((as == sender) || (!as->reader))
1117 as->event_head = (as->event_head + 1) % APM_MAX_EVENTS;
1118 if (as->event_head == as->event_tail) {
1119 static int notified;
1121 if (notified++ == 0)
1122 printk(KERN_ERR "apm: an event queue overflowed\n");
1123 as->event_tail = (as->event_tail + 1) % APM_MAX_EVENTS;
1125 as->events[as->event_head] = event;
1126 if ((!as->suser) || (!as->writer))
1129 case APM_SYS_SUSPEND:
1130 case APM_USER_SUSPEND:
1131 as->suspends_pending++;
1135 case APM_SYS_STANDBY:
1136 case APM_USER_STANDBY:
1137 as->standbys_pending++;
1142 wake_up_interruptible(&apm_waitqueue);
1144 spin_unlock(&user_list_lock);
1147 static void set_time(void)
1149 if (got_clock_diff) { /* Must know time zone in order to set clock */
1150 xtime.tv_sec = get_cmos_time() + clock_cmos_diff;
1155 static void get_time_diff(void)
1157 #ifndef CONFIG_APM_RTC_IS_GMT
1159 * Estimate time zone so that set_time can update the clock
1161 clock_cmos_diff = -get_cmos_time();
1162 clock_cmos_diff += get_seconds();
1167 static void reinit_timer(void)
1169 #ifdef INIT_TIMER_AFTER_SUSPEND
1170 unsigned long flags;
1171 extern spinlock_t i8253_lock;
1173 spin_lock_irqsave(&i8253_lock, flags);
1174 /* set the clock to 100 Hz */
1175 outb_p(0x34, PIT_MODE); /* binary, mode 2, LSB/MSB, ch 0 */
1177 outb_p(LATCH & 0xff, PIT_CH0); /* LSB */
1179 outb(LATCH >> 8, PIT_CH0); /* MSB */
1181 spin_unlock_irqrestore(&i8253_lock, flags);
1185 static int suspend(int vetoable)
1188 struct apm_user *as;
1190 if (pm_send_all(PM_SUSPEND, (void *)3)) {
1193 if (apm_info.connection_version > 0x100)
1194 set_system_power_state(APM_STATE_REJECT);
1196 ignore_sys_suspend = 0;
1197 printk(KERN_WARNING "apm: suspend was vetoed.\n");
1200 printk(KERN_CRIT "apm: suspend was vetoed, but suspending anyway.\n");
1204 device_power_down(3);
1206 /* serialize with the timer interrupt */
1207 write_seqlock_irq(&xtime_lock);
1209 /* protect against access to timer chip registers */
1210 spin_lock(&i8253_lock);
1214 * Irq spinlock must be dropped around set_system_power_state.
1215 * We'll undo any timer changes due to interrupts below.
1217 spin_unlock(&i8253_lock);
1218 write_sequnlock_irq(&xtime_lock);
1220 save_processor_state();
1221 err = set_system_power_state(APM_STATE_SUSPEND);
1222 restore_processor_state();
1224 write_seqlock_irq(&xtime_lock);
1225 spin_lock(&i8253_lock);
1228 ignore_normal_resume = 1;
1230 spin_unlock(&i8253_lock);
1231 write_sequnlock_irq(&xtime_lock);
1233 if (err == APM_NO_ERROR)
1235 if (err != APM_SUCCESS)
1236 apm_error("suspend", err);
1237 err = (err == APM_SUCCESS) ? 0 : -EIO;
1240 pm_send_all(PM_RESUME, (void *)0);
1241 queue_event(APM_NORMAL_RESUME, NULL);
1243 spin_lock(&user_list_lock);
1244 for (as = user_list; as != NULL; as = as->next) {
1245 as->suspend_wait = 0;
1246 as->suspend_result = err;
1248 spin_unlock(&user_list_lock);
1249 wake_up_interruptible(&apm_suspend_waitqueue);
1253 static void standby(void)
1257 device_power_down(3);
1258 /* serialize with the timer interrupt */
1259 write_seqlock_irq(&xtime_lock);
1260 /* If needed, notify drivers here */
1262 write_sequnlock_irq(&xtime_lock);
1264 err = set_system_power_state(APM_STATE_STANDBY);
1265 if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1266 apm_error("standby", err);
1270 static apm_event_t get_event(void)
1274 apm_eventinfo_t info;
1276 static int notified;
1278 /* we don't use the eventinfo */
1279 error = apm_get_event(&event, &info);
1280 if (error == APM_SUCCESS)
1283 if ((error != APM_NO_EVENTS) && (notified++ == 0))
1284 apm_error("get_event", error);
1289 static void check_events(void)
1292 static unsigned long last_resume;
1293 static int ignore_bounce;
1295 while ((event = get_event()) != 0) {
1297 if (event <= NR_APM_EVENT_NAME)
1298 printk(KERN_DEBUG "apm: received %s notify\n",
1299 apm_event_name[event - 1]);
1301 printk(KERN_DEBUG "apm: received unknown "
1302 "event 0x%02x\n", event);
1305 && ((jiffies - last_resume) > bounce_interval))
1309 case APM_SYS_STANDBY:
1310 case APM_USER_STANDBY:
1311 queue_event(event, NULL);
1312 if (standbys_pending <= 0)
1316 case APM_USER_SUSPEND:
1317 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1318 if (apm_info.connection_version > 0x100)
1319 set_system_power_state(APM_STATE_REJECT);
1322 case APM_SYS_SUSPEND:
1323 if (ignore_bounce) {
1324 if (apm_info.connection_version > 0x100)
1325 set_system_power_state(APM_STATE_REJECT);
1329 * If we are already processing a SUSPEND,
1330 * then further SUSPEND events from the BIOS
1331 * will be ignored. We also return here to
1332 * cope with the fact that the Thinkpads keep
1333 * sending a SUSPEND event until something else
1336 if (ignore_sys_suspend)
1338 ignore_sys_suspend = 1;
1339 queue_event(event, NULL);
1340 if (suspends_pending <= 0)
1344 case APM_NORMAL_RESUME:
1345 case APM_CRITICAL_RESUME:
1346 case APM_STANDBY_RESUME:
1347 ignore_sys_suspend = 0;
1348 last_resume = jiffies;
1350 if ((event != APM_NORMAL_RESUME)
1351 || (ignore_normal_resume == 0)) {
1352 write_seqlock_irq(&xtime_lock);
1354 write_sequnlock_irq(&xtime_lock);
1356 pm_send_all(PM_RESUME, (void *)0);
1357 queue_event(event, NULL);
1359 ignore_normal_resume = 0;
1362 case APM_CAPABILITY_CHANGE:
1363 case APM_LOW_BATTERY:
1364 case APM_POWER_STATUS_CHANGE:
1365 queue_event(event, NULL);
1366 /* If needed, notify drivers here */
1369 case APM_UPDATE_TIME:
1370 write_seqlock_irq(&xtime_lock);
1372 write_sequnlock_irq(&xtime_lock);
1375 case APM_CRITICAL_SUSPEND:
1377 * We are not allowed to reject a critical suspend.
1385 static void apm_event_handler(void)
1387 static int pending_count = 4;
1390 if ((standbys_pending > 0) || (suspends_pending > 0)) {
1391 if ((apm_info.connection_version > 0x100) &&
1392 (pending_count-- <= 0)) {
1395 printk(KERN_DEBUG "apm: setting state busy\n");
1396 err = set_system_power_state(APM_STATE_BUSY);
1398 apm_error("busy", err);
1406 * This is the APM thread main loop.
1409 static void apm_mainloop(void)
1411 DECLARE_WAITQUEUE(wait, current);
1413 add_wait_queue(&apm_waitqueue, &wait);
1414 set_current_state(TASK_INTERRUPTIBLE);
1416 schedule_timeout(APM_CHECK_TIMEOUT);
1420 * Ok, check all events, check for idle (and mark us sleeping
1421 * so as not to count towards the load average)..
1423 set_current_state(TASK_INTERRUPTIBLE);
1424 apm_event_handler();
1426 remove_wait_queue(&apm_waitqueue, &wait);
1429 static int check_apm_user(struct apm_user *as, const char *func)
1431 if ((as == NULL) || (as->magic != APM_BIOS_MAGIC)) {
1432 printk(KERN_ERR "apm: %s passed bad filp\n", func);
1438 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1440 struct apm_user * as;
1444 as = fp->private_data;
1445 if (check_apm_user(as, "read"))
1447 if ((int)count < sizeof(apm_event_t))
1449 if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1451 wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1453 while ((i >= sizeof(event)) && !queue_empty(as)) {
1454 event = get_queued_event(as);
1455 if (copy_to_user(buf, &event, sizeof(event))) {
1461 case APM_SYS_SUSPEND:
1462 case APM_USER_SUSPEND:
1463 as->suspends_read++;
1466 case APM_SYS_STANDBY:
1467 case APM_USER_STANDBY:
1468 as->standbys_read++;
1471 buf += sizeof(event);
1476 if (signal_pending(current))
1477 return -ERESTARTSYS;
1481 static unsigned int do_poll(struct file *fp, poll_table * wait)
1483 struct apm_user * as;
1485 as = fp->private_data;
1486 if (check_apm_user(as, "poll"))
1488 poll_wait(fp, &apm_waitqueue, wait);
1489 if (!queue_empty(as))
1490 return POLLIN | POLLRDNORM;
1494 static int do_ioctl(struct inode * inode, struct file *filp,
1495 u_int cmd, u_long arg)
1497 struct apm_user * as;
1499 as = filp->private_data;
1500 if (check_apm_user(as, "ioctl"))
1502 if ((!as->suser) || (!as->writer))
1505 case APM_IOC_STANDBY:
1506 if (as->standbys_read > 0) {
1507 as->standbys_read--;
1508 as->standbys_pending--;
1511 queue_event(APM_USER_STANDBY, as);
1512 if (standbys_pending <= 0)
1515 case APM_IOC_SUSPEND:
1516 if (as->suspends_read > 0) {
1517 as->suspends_read--;
1518 as->suspends_pending--;
1521 queue_event(APM_USER_SUSPEND, as);
1522 if (suspends_pending <= 0) {
1525 as->suspend_wait = 1;
1526 wait_event_interruptible(apm_suspend_waitqueue,
1527 as->suspend_wait == 0);
1528 return as->suspend_result;
1537 static int do_release(struct inode * inode, struct file * filp)
1539 struct apm_user * as;
1541 as = filp->private_data;
1542 if (check_apm_user(as, "release"))
1544 filp->private_data = NULL;
1545 if (as->standbys_pending > 0) {
1546 standbys_pending -= as->standbys_pending;
1547 if (standbys_pending <= 0)
1550 if (as->suspends_pending > 0) {
1551 suspends_pending -= as->suspends_pending;
1552 if (suspends_pending <= 0)
1555 spin_lock(&user_list_lock);
1556 if (user_list == as)
1557 user_list = as->next;
1559 struct apm_user * as1;
1561 for (as1 = user_list;
1562 (as1 != NULL) && (as1->next != as);
1566 printk(KERN_ERR "apm: filp not in user list\n");
1568 as1->next = as->next;
1570 spin_unlock(&user_list_lock);
1575 static int do_open(struct inode * inode, struct file * filp)
1577 struct apm_user * as;
1579 as = (struct apm_user *)kmalloc(sizeof(*as), GFP_KERNEL);
1581 printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
1585 as->magic = APM_BIOS_MAGIC;
1586 as->event_tail = as->event_head = 0;
1587 as->suspends_pending = as->standbys_pending = 0;
1588 as->suspends_read = as->standbys_read = 0;
1590 * XXX - this is a tiny bit broken, when we consider BSD
1591 * process accounting. If the device is opened by root, we
1592 * instantly flag that we used superuser privs. Who knows,
1593 * we might close the device immediately without doing a
1594 * privileged operation -- cevans
1596 as->suser = capable(CAP_SYS_ADMIN);
1597 as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1598 as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1599 spin_lock(&user_list_lock);
1600 as->next = user_list;
1602 spin_unlock(&user_list_lock);
1603 filp->private_data = as;
1607 static int apm_get_info(char *buf, char **start, off_t fpos, int length)
1614 unsigned short ac_line_status = 0xff;
1615 unsigned short battery_status = 0xff;
1616 unsigned short battery_flag = 0xff;
1617 int percentage = -1;
1618 int time_units = -1;
1623 if ((num_online_cpus() == 1) &&
1624 !(error = apm_get_power_status(&bx, &cx, &dx))) {
1625 ac_line_status = (bx >> 8) & 0xff;
1626 battery_status = bx & 0xff;
1627 if ((cx & 0xff) != 0xff)
1628 percentage = cx & 0xff;
1630 if (apm_info.connection_version > 0x100) {
1631 battery_flag = (cx >> 8) & 0xff;
1633 units = (dx & 0x8000) ? "min" : "sec";
1634 time_units = dx & 0x7fff;
1638 /* Arguments, with symbols from linux/apm_bios.h. Information is
1639 from the Get Power Status (0x0a) call unless otherwise noted.
1641 0) Linux driver version (this will change if format changes)
1642 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2.
1643 2) APM flags from APM Installation Check (0x00):
1644 bit 0: APM_16_BIT_SUPPORT
1645 bit 1: APM_32_BIT_SUPPORT
1646 bit 2: APM_IDLE_SLOWS_CLOCK
1647 bit 3: APM_BIOS_DISABLED
1648 bit 4: APM_BIOS_DISENGAGED
1652 0x02: On backup power (BIOS >= 1.1 only)
1659 0x04: Selected battery not present (BIOS >= 1.2 only)
1666 bit 7: No system battery
1668 6) Remaining battery life (percentage of charge):
1671 7) Remaining battery life (time units):
1672 Number of remaining minutes or seconds
1674 8) min = minutes; sec = seconds */
1676 p += sprintf(p, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1678 (apm_info.bios.version >> 8) & 0xff,
1679 apm_info.bios.version & 0xff,
1680 apm_info.bios.flags,
1691 static int apm(void *unused)
1704 current->flags |= PF_NOFREEZE;
1708 * This is to avoid random crashes at boot time during initialization
1709 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1710 * Some bioses don't like being called from CPU != 0.
1711 * Method suggested by Ingo Molnar.
1713 set_cpus_allowed(current, cpumask_of_cpu(0));
1714 BUG_ON(smp_processor_id() != 0);
1717 if (apm_info.connection_version == 0) {
1718 apm_info.connection_version = apm_info.bios.version;
1719 if (apm_info.connection_version > 0x100) {
1721 * We only support BIOSs up to version 1.2
1723 if (apm_info.connection_version > 0x0102)
1724 apm_info.connection_version = 0x0102;
1725 error = apm_driver_version(&apm_info.connection_version);
1726 if (error != APM_SUCCESS) {
1727 apm_error("driver version", error);
1728 /* Fall back to an APM 1.0 connection. */
1729 apm_info.connection_version = 0x100;
1735 printk(KERN_INFO "apm: Connection version %d.%d\n",
1736 (apm_info.connection_version >> 8) & 0xff,
1737 apm_info.connection_version & 0xff);
1739 #ifdef CONFIG_APM_DO_ENABLE
1740 if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1742 * This call causes my NEC UltraLite Versa 33/C to hang if it
1743 * is booted with PM disabled but not in the docking station.
1746 error = apm_enable_power_management(1);
1748 apm_error("enable power management", error);
1754 if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1755 && (apm_info.connection_version > 0x0100)) {
1756 error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1758 apm_error("engage power management", error);
1763 if (debug && (num_online_cpus() == 1 || smp )) {
1764 error = apm_get_power_status(&bx, &cx, &dx);
1766 printk(KERN_INFO "apm: power status not available\n");
1768 switch ((bx >> 8) & 0xff) {
1769 case 0: power_stat = "off line"; break;
1770 case 1: power_stat = "on line"; break;
1771 case 2: power_stat = "on backup power"; break;
1772 default: power_stat = "unknown"; break;
1774 switch (bx & 0xff) {
1775 case 0: bat_stat = "high"; break;
1776 case 1: bat_stat = "low"; break;
1777 case 2: bat_stat = "critical"; break;
1778 case 3: bat_stat = "charging"; break;
1779 default: bat_stat = "unknown"; break;
1782 "apm: AC %s, battery status %s, battery life ",
1783 power_stat, bat_stat);
1784 if ((cx & 0xff) == 0xff)
1785 printk("unknown\n");
1787 printk("%d%%\n", cx & 0xff);
1788 if (apm_info.connection_version > 0x100) {
1790 "apm: battery flag 0x%02x, battery life ",
1793 printk("unknown\n");
1795 printk("%d %s\n", dx & 0x7fff,
1797 "minutes" : "seconds");
1802 /* Install our power off handler.. */
1804 pm_power_off = apm_power_off;
1806 if (num_online_cpus() == 1 || smp) {
1807 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1808 console_blank_hook = apm_console_blank;
1811 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1812 console_blank_hook = NULL;
1821 static int __init apm_setup(char *str)
1825 while ((str != NULL) && (*str != '\0')) {
1826 if (strncmp(str, "off", 3) == 0)
1828 if (strncmp(str, "on", 2) == 0)
1830 if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1831 (strncmp(str, "bounce_interval=", 16) == 0))
1832 bounce_interval = simple_strtol(str + 16, NULL, 0);
1833 if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1834 (strncmp(str, "idle_threshold=", 15) == 0))
1835 idle_threshold = simple_strtol(str + 15, NULL, 0);
1836 if ((strncmp(str, "idle-period=", 12) == 0) ||
1837 (strncmp(str, "idle_period=", 12) == 0))
1838 idle_period = simple_strtol(str + 12, NULL, 0);
1839 invert = (strncmp(str, "no-", 3) == 0) ||
1840 (strncmp(str, "no_", 3) == 0);
1843 if (strncmp(str, "debug", 5) == 0)
1845 if ((strncmp(str, "power-off", 9) == 0) ||
1846 (strncmp(str, "power_off", 9) == 0))
1847 power_off = !invert;
1848 if (strncmp(str, "smp", 3) == 0)
1851 idle_threshold = 100;
1853 if ((strncmp(str, "allow-ints", 10) == 0) ||
1854 (strncmp(str, "allow_ints", 10) == 0))
1855 apm_info.allow_ints = !invert;
1856 if ((strncmp(str, "broken-psr", 10) == 0) ||
1857 (strncmp(str, "broken_psr", 10) == 0))
1858 apm_info.get_power_status_broken = !invert;
1859 if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1860 (strncmp(str, "realmode_power_off", 18) == 0))
1861 apm_info.realmode_power_off = !invert;
1862 str = strchr(str, ',');
1864 str += strspn(str, ", \t");
1869 __setup("apm=", apm_setup);
1872 static struct file_operations apm_bios_fops = {
1873 .owner = THIS_MODULE,
1878 .release = do_release,
1881 static struct miscdevice apm_device = {
1888 * Just start the APM thread. We do NOT want to do APM BIOS
1889 * calls from anything but the APM thread, if for no other reason
1890 * than the fact that we don't trust the APM BIOS. This way,
1891 * most common APM BIOS problems that lead to protection errors
1892 * etc will have at least some level of being contained...
1894 * In short, if something bad happens, at least we have a choice
1895 * of just killing the apm thread..
1897 static int __init apm_init(void)
1899 struct proc_dir_entry *apm_proc;
1903 if (apm_info.bios.version == 0) {
1904 printk(KERN_INFO "apm: BIOS not found.\n");
1908 "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
1909 ((apm_info.bios.version >> 8) & 0xff),
1910 (apm_info.bios.version & 0xff),
1911 apm_info.bios.flags,
1913 if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
1914 printk(KERN_INFO "apm: no 32 bit BIOS support\n");
1919 apm_info.allow_ints = 1;
1921 apm_info.get_power_status_broken = 1;
1922 if (realmode_power_off)
1923 apm_info.realmode_power_off = 1;
1924 /* User can override, but default is to trust DMI */
1925 if (apm_disabled != -1)
1926 apm_info.disabled = apm_disabled;
1929 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
1930 * but is reportedly a 1.0 BIOS.
1932 if (apm_info.bios.version == 0x001)
1933 apm_info.bios.version = 0x100;
1935 /* BIOS < 1.2 doesn't set cseg_16_len */
1936 if (apm_info.bios.version < 0x102)
1937 apm_info.bios.cseg_16_len = 0; /* 64k */
1940 printk(KERN_INFO "apm: entry %x:%lx cseg16 %x dseg %x",
1941 apm_info.bios.cseg, apm_info.bios.offset,
1942 apm_info.bios.cseg_16, apm_info.bios.dseg);
1943 if (apm_info.bios.version > 0x100)
1944 printk(" cseg len %x, dseg len %x",
1945 apm_info.bios.cseg_len,
1946 apm_info.bios.dseg_len);
1947 if (apm_info.bios.version > 0x101)
1948 printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
1952 if (apm_info.disabled) {
1953 printk(KERN_NOTICE "apm: disabled on user request.\n");
1956 if ((num_online_cpus() > 1) && !power_off && !smp) {
1957 printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
1960 if (PM_IS_ACTIVE()) {
1961 printk(KERN_NOTICE "apm: overridden by ACPI.\n");
1967 * Set up a segment that references the real mode segment 0x40
1968 * that extends up to the end of page zero (that we have reserved).
1969 * This is for buggy BIOS's that refer to (real mode) segment 0x40
1970 * even though they are called in protected mode.
1972 set_base(bad_bios_desc, __va((unsigned long)0x40 << 4));
1973 _set_limit((char *)&bad_bios_desc, 4095 - (0x40 << 4));
1975 apm_bios_entry.offset = apm_info.bios.offset;
1976 apm_bios_entry.segment = APM_CS;
1978 for (i = 0; i < NR_CPUS; i++) {
1979 set_base(cpu_gdt_table[i][APM_CS >> 3],
1980 __va((unsigned long)apm_info.bios.cseg << 4));
1981 set_base(cpu_gdt_table[i][APM_CS_16 >> 3],
1982 __va((unsigned long)apm_info.bios.cseg_16 << 4));
1983 set_base(cpu_gdt_table[i][APM_DS >> 3],
1984 __va((unsigned long)apm_info.bios.dseg << 4));
1985 #ifndef APM_RELAX_SEGMENTS
1986 if (apm_info.bios.version == 0x100) {
1988 /* For ASUS motherboard, Award BIOS rev 110 (and others?) */
1989 _set_limit((char *)&cpu_gdt_table[i][APM_CS >> 3], 64 * 1024 - 1);
1990 /* For some unknown machine. */
1991 _set_limit((char *)&cpu_gdt_table[i][APM_CS_16 >> 3], 64 * 1024 - 1);
1992 /* For the DEC Hinote Ultra CT475 (and others?) */
1993 _set_limit((char *)&cpu_gdt_table[i][APM_DS >> 3], 64 * 1024 - 1);
1994 #ifndef APM_RELAX_SEGMENTS
1996 _set_limit((char *)&cpu_gdt_table[i][APM_CS >> 3],
1997 (apm_info.bios.cseg_len - 1) & 0xffff);
1998 _set_limit((char *)&cpu_gdt_table[i][APM_CS_16 >> 3],
1999 (apm_info.bios.cseg_16_len - 1) & 0xffff);
2000 _set_limit((char *)&cpu_gdt_table[i][APM_DS >> 3],
2001 (apm_info.bios.dseg_len - 1) & 0xffff);
2002 /* workaround for broken BIOSes */
2003 if (apm_info.bios.cseg_len <= apm_info.bios.offset)
2004 _set_limit((char *)&cpu_gdt_table[i][APM_CS >> 3], 64 * 1024 -1);
2005 if (apm_info.bios.dseg_len <= 0x40) { /* 0x40 * 4kB == 64kB */
2006 /* for the BIOS that assumes granularity = 1 */
2007 cpu_gdt_table[i][APM_DS >> 3].b |= 0x800000;
2008 printk(KERN_NOTICE "apm: we set the granularity of dseg.\n");
2014 apm_proc = create_proc_info_entry("apm", 0, NULL, apm_get_info);
2016 apm_proc->owner = THIS_MODULE;
2018 ret = kernel_thread(apm, NULL, CLONE_KERNEL | SIGCHLD);
2020 printk(KERN_ERR "apm: disabled - Unable to start kernel thread.\n");
2024 if (num_online_cpus() > 1 && !smp ) {
2026 "apm: disabled - APM is not SMP safe (power off active).\n");
2030 misc_register(&apm_device);
2033 idle_period = (idle_period * HZ) / 100;
2034 if (idle_threshold < 100) {
2035 original_pm_idle = pm_idle;
2036 pm_idle = apm_cpu_idle;
2043 static void __exit apm_exit(void)
2048 pm_idle = original_pm_idle;
2049 if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2050 && (apm_info.connection_version > 0x0100)) {
2051 error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2053 apm_error("disengage power management", error);
2055 misc_deregister(&apm_device);
2056 remove_proc_entry("apm", NULL);
2058 pm_power_off = NULL;
2060 while (kapmd_running)
2065 module_init(apm_init);
2066 module_exit(apm_exit);
2068 MODULE_AUTHOR("Stephen Rothwell");
2069 MODULE_DESCRIPTION("Advanced Power Management");
2070 MODULE_LICENSE("GPL");
2071 MODULE_PARM(debug, "i");
2072 MODULE_PARM_DESC(debug, "Enable debug mode");
2073 MODULE_PARM(power_off, "i");
2074 MODULE_PARM_DESC(power_off, "Enable power off");
2075 MODULE_PARM(bounce_interval, "i");
2076 MODULE_PARM_DESC(bounce_interval,
2077 "Set the number of ticks to ignore suspend bounces");
2078 MODULE_PARM(allow_ints, "i");
2079 MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2080 MODULE_PARM(broken_psr, "i");
2081 MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2082 MODULE_PARM(realmode_power_off, "i");
2083 MODULE_PARM_DESC(realmode_power_off,
2084 "Switch to real mode before powering off");
2085 MODULE_PARM(idle_threshold, "i");
2086 MODULE_PARM_DESC(idle_threshold,
2087 "System idle percentage above which to make APM BIOS idle calls");
2088 MODULE_PARM(idle_period, "i");
2089 MODULE_PARM_DESC(idle_period,
2090 "Period (in sec/100) over which to caculate the idle percentage");
2091 MODULE_PARM(smp, "i");
2092 MODULE_PARM_DESC(smp,
2093 "Set this to enable APM use on an SMP platform. Use with caution on older systems");
2094 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);