1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * APM BIOS driver for Linux
4 * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
6 * Initial development of this driver was funded by NEC Australia P/L
9 * October 1995, Rik Faith (faith@cs.unc.edu):
10 * Minor enhancements and updates (to the patch set) for 1.3.x
12 * January 1996, Rik Faith (faith@cs.unc.edu):
13 * Make /proc/apm easy to format (bump driver version)
14 * March 1996, Rik Faith (faith@cs.unc.edu):
15 * Prohibit APM BIOS calls unless apm_enabled.
16 * (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
17 * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
19 * May 1996, Version 1.2
20 * Feb 1998, Version 1.3
21 * Feb 1998, Version 1.4
22 * Aug 1998, Version 1.5
23 * Sep 1998, Version 1.6
24 * Nov 1998, Version 1.7
25 * Jan 1999, Version 1.8
26 * Jan 1999, Version 1.9
27 * Oct 1999, Version 1.10
28 * Nov 1999, Version 1.11
29 * Jan 2000, Version 1.12
30 * Feb 2000, Version 1.13
31 * Nov 2000, Version 1.14
32 * Oct 2001, Version 1.15
33 * Jan 2002, Version 1.16
34 * Oct 2002, Version 1.16ac
37 * 0.6b: first version in official kernel, Linux 1.3.46
38 * 0.7: changed /proc/apm format, Linux 1.3.58
39 * 0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
40 * 0.9: only call bios if bios is present, Linux 1.3.72
41 * 1.0: use fixed device number, consolidate /proc/apm into this file,
43 * 1.1: support user-space standby and suspend, power off after system
44 * halted, Linux 1.3.98
45 * 1.2: When resetting RTC after resume, take care so that the time
46 * is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
47 * <jtoth@princeton.edu>); improve interaction between
48 * screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
49 * 1.2a:Simple change to stop mysterious bug reports with SMP also added
50 * levels to the printk calls. APM is not defined for SMP machines.
51 * The new replacement for it is, but Linux doesn't yet support this.
52 * Alan Cox Linux 2.1.55
53 * 1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
54 * 1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
55 * Dean Gaudet <dgaudet@arctic.org>.
56 * C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
57 * 1.5: Fix segment register reloading (in case of bad segments saved
60 * 1.6: Cope with compiler/assembler differences.
61 * Only try to turn off the first display device.
62 * Fix OOPS at power off with no APM BIOS by Jan Echternach
63 * <echter@informatik.uni-rostock.de>
65 * 1.7: Modify driver's cached copy of the disabled/disengaged flags
66 * to reflect current state of APM BIOS.
67 * Chris Rankin <rankinc@bellsouth.net>
68 * Reset interrupt 0 timer to 100Hz after suspend
69 * Chad Miller <cmiller@surfsouth.com>
70 * Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
71 * Richard Gooch <rgooch@atnf.csiro.au>
72 * Allow boot time disabling of APM
73 * Make boot messages far less verbose by default
76 * 1.8: Add CONFIG_APM_RTC_IS_GMT
77 * Richard Gooch <rgooch@atnf.csiro.au>
78 * change APM_NOINTS to CONFIG_APM_ALLOW_INTS
79 * remove dependency on CONFIG_PROC_FS
81 * 1.9: Fix small typo. <laslo@wodip.opole.pl>
82 * Try to cope with BIOS's that need to have all display
83 * devices blanked and not just the first one.
84 * Ross Paterson <ross@soi.city.ac.uk>
85 * Fix segment limit setting it has always been wrong as
86 * the segments needed to have byte granularity.
87 * Mark a few things __init.
88 * Add hack to allow power off of SMP systems by popular request.
89 * Use CONFIG_SMP instead of __SMP__
90 * Ignore BOUNCES for three seconds.
92 * 1.10: Fix for Thinkpad return code.
93 * Merge 2.2 and 2.3 drivers.
94 * Remove APM dependencies in arch/i386/kernel/process.c
95 * Remove APM dependencies in drivers/char/sysrq.c
96 * Reset time across standby.
97 * Allow more inititialisation on SMP.
98 * Remove CONFIG_APM_POWER_OFF and make it boot time
99 * configurable (default on).
100 * Make debug only a boot time parameter (remove APM_DEBUG).
101 * Try to blank all devices on any error.
102 * 1.11: Remove APM dependencies in drivers/char/console.c
103 * Check nr_running to detect if we are idle (from
104 * Borislav Deianov <borislav@lix.polytechnique.fr>)
105 * Fix for bioses that don't zero the top part of the
106 * entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
107 * (reported by Panos Katsaloulis <teras@writeme.com>).
108 * Real mode power off patch (Walter Hofmann
109 * <Walter.Hofmann@physik.stud.uni-erlangen.de>).
110 * 1.12: Remove CONFIG_SMP as the compiler will optimize
111 * the code away anyway (smp_num_cpus == 1 in UP)
112 * noted by Artur Skawina <skawina@geocities.com>.
113 * Make power off under SMP work again.
114 * Fix thinko with initial engaging of BIOS.
115 * Make sure power off only happens on CPU 0
116 * (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
117 * Do error notification to user mode if BIOS calls fail.
118 * Move entrypoint offset fix to ...boot/setup.S
119 * where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
120 * Remove smp-power-off. SMP users must now specify
121 * "apm=power-off" on the kernel command line. Suggested
122 * by Jim Avera <jima@hal.com>, modified by Alan Cox
123 * <alan@lxorguk.ukuu.org.uk>.
124 * Register the /proc/apm entry even on SMP so that
125 * scripts that check for it before doing power off
126 * work (Jim Avera <jima@hal.com>).
127 * 1.13: Changes for new pm_ interfaces (Andy Henroid
128 * <andy_henroid@yahoo.com>).
129 * Modularize the code.
130 * Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
131 * is now the way life works).
132 * Fix thinko in suspend() (wrong return).
133 * Notify drivers on critical suspend.
134 * Make kapmd absorb more idle time (Pavel Machek <pavel@ucw.cz>
136 * Disable interrupts while we are suspended (Andy Henroid
137 * <andy_henroid@yahoo.com> fixed by sfr).
138 * Make power off work on SMP again (Tony Hoyle
139 * <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
140 * Remove CONFIG_APM_SUSPEND_BOUNCE. The bounce ignore
141 * interval is now configurable.
142 * 1.14: Make connection version persist across module unload/load.
143 * Enable and engage power management earlier.
144 * Disengage power management on module unload.
145 * Changed to use the sysrq-register hack for registering the
146 * power off function called by magic sysrq based upon discussions
147 * in irc://irc.openprojects.net/#kernelnewbies
148 * (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
149 * Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
150 * (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
151 * Work around byte swap bug in one of the Vaio's BIOS's
152 * (Marc Boucher <marc@mbsi.ca>).
153 * Exposed the disable flag to dmi so that we can handle known
154 * broken APM (Alan Cox <alan@lxorguk.ukuu.org.uk>).
155 * 1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
156 * calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
157 * If an APM idle fails log it and idle sensibly
158 * 1.15: Don't queue events to clients who open the device O_WRONLY.
159 * Don't expect replies from clients who open the device O_RDONLY.
160 * (Idea from Thomas Hood)
161 * Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
162 * 1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
163 * Notify listeners of standby or suspend events before notifying
164 * drivers. Return EBUSY to ioctl() if suspend is rejected.
165 * (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
166 * Ignore first resume after we generate our own resume event
167 * after a suspend (Thomas Hood)
168 * Daemonize now gets rid of our controlling terminal (sfr).
169 * CONFIG_APM_CPU_IDLE now just affects the default value of
170 * idle_threshold (sfr).
171 * Change name of kernel apm daemon (as it no longer idles) (sfr).
172 * 1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
173 * make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
174 * TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
178 * Intel Corporation, Microsoft Corporation. Advanced Power Management
179 * (APM) BIOS Interface Specification, Revision 1.1, September 1993.
180 * Intel Order Number 241704-001. Microsoft Part Number 781-110-X01.
182 * [This document is available free from Intel by calling 800.628.8686 (fax
183 * 916.356.6100) or 800.548.4725; or from
184 * http://www.microsoft.com/whdc/archive/amp_12.mspx It is also
185 * available from Microsoft by calling 206.882.8080.]
188 * Intel Corporation, Microsoft Corporation. Advanced Power Management
189 * (APM) BIOS Interface Specification, Revision 1.2, February 1996.
191 * [This document is available from Microsoft at:
192 * http://www.microsoft.com/whdc/archive/amp_12.mspx]
195 #define pr_fmt(fmt) "apm: " fmt
197 #include <linux/module.h>
199 #include <linux/poll.h>
200 #include <linux/types.h>
201 #include <linux/stddef.h>
202 #include <linux/timer.h>
203 #include <linux/fcntl.h>
204 #include <linux/slab.h>
205 #include <linux/stat.h>
206 #include <linux/proc_fs.h>
207 #include <linux/seq_file.h>
208 #include <linux/miscdevice.h>
209 #include <linux/apm_bios.h>
210 #include <linux/init.h>
211 #include <linux/time.h>
212 #include <linux/sched/signal.h>
213 #include <linux/sched/cputime.h>
214 #include <linux/pm.h>
215 #include <linux/capability.h>
216 #include <linux/device.h>
217 #include <linux/kernel.h>
218 #include <linux/freezer.h>
219 #include <linux/smp.h>
220 #include <linux/dmi.h>
221 #include <linux/suspend.h>
222 #include <linux/kthread.h>
223 #include <linux/jiffies.h>
224 #include <linux/acpi.h>
225 #include <linux/syscore_ops.h>
226 #include <linux/i8253.h>
227 #include <linux/cpuidle.h>
229 #include <linux/uaccess.h>
230 #include <asm/desc.h>
231 #include <asm/olpc.h>
232 #include <asm/paravirt.h>
233 #include <asm/reboot.h>
234 #include <asm/nospec-branch.h>
236 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
237 extern int (*console_blank_hook)(int);
241 * Various options can be changed at boot time as follows:
242 * (We allow underscores for compatibility with the modules code)
243 * apm=on/off enable/disable APM
244 * [no-]allow[-_]ints allow interrupts during BIOS calls
245 * [no-]broken[-_]psr BIOS has a broken GetPowerStatus call
246 * [no-]realmode[-_]power[-_]off switch to real mode before
248 * [no-]debug log some debugging messages
249 * [no-]power[-_]off power off on shutdown
250 * [no-]smp Use apm even on an SMP box
251 * bounce[-_]interval=<n> number of ticks to ignore suspend
253 * idle[-_]threshold=<n> System idle percentage above which to
254 * make APM BIOS idle calls. Set it to
256 * idle[-_]period=<n> Period (in 1/100s of a second) over
257 * which the idle percentage is
261 /* KNOWN PROBLEM MACHINES:
263 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
264 * [Confirmed by TI representative]
265 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
266 * [Confirmed by BIOS disassembly]
267 * [This may work now ...]
268 * P: Toshiba 1950S: battery life information only gets updated after resume
269 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
270 * broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
271 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
272 * Neale Banks <neale@lowendale.com.au> December 2000
274 * Legend: U = unusable with APM patches
275 * P = partially usable with APM patches
279 * Define as 1 to make the driver always call the APM BIOS busy
280 * routine even if the clock was not reported as slowed by the
281 * idle routine. Otherwise, define as 0.
283 #define ALWAYS_CALL_BUSY 1
286 * Define to make the APM BIOS calls zero all data segment registers (so
287 * that an incorrect BIOS implementation will cause a kernel panic if it
288 * tries to write to arbitrary memory).
290 #define APM_ZERO_SEGS
295 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
296 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
297 * David Chen <chen@ctpa04.mit.edu>
299 #undef INIT_TIMER_AFTER_SUSPEND
301 #ifdef INIT_TIMER_AFTER_SUSPEND
302 #include <linux/timex.h>
304 #include <linux/delay.h>
308 * Need to poll the APM BIOS every second
310 #define APM_CHECK_TIMEOUT (HZ)
313 * Ignore suspend events for this amount of time after a resume
315 #define DEFAULT_BOUNCE_INTERVAL (3 * HZ)
318 * Maximum number of events stored
320 #define APM_MAX_EVENTS 20
323 * The per-file APM data
327 struct apm_user *next;
328 unsigned int suser: 1;
329 unsigned int writer: 1;
330 unsigned int reader: 1;
331 unsigned int suspend_wait: 1;
333 int suspends_pending;
334 int standbys_pending;
339 apm_event_t events[APM_MAX_EVENTS];
343 * The magic number in apm_user
345 #define APM_BIOS_MAGIC 0x4101
348 * idle percentage above which bios idle calls are done
350 #ifdef CONFIG_APM_CPU_IDLE
351 #define DEFAULT_IDLE_THRESHOLD 95
353 #define DEFAULT_IDLE_THRESHOLD 100
355 #define DEFAULT_IDLE_PERIOD (100 / 3)
357 static int apm_cpu_idle(struct cpuidle_device *dev,
358 struct cpuidle_driver *drv, int index);
360 static struct cpuidle_driver apm_idle_driver = {
362 .owner = THIS_MODULE,
364 { /* entry 0 is for polling */ },
365 { /* entry 1 is for APM idle */
368 .exit_latency = 250, /* WAG */
369 .target_residency = 500, /* WAG */
370 .enter = &apm_cpu_idle
376 static struct cpuidle_device apm_cpuidle_device;
382 unsigned long offset;
383 unsigned short segment;
385 static int clock_slowed;
386 static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
387 static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
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 __read_mostly = DEFAULT_BOUNCE_INTERVAL;
394 static bool debug __read_mostly;
395 static bool smp __read_mostly;
396 static int apm_disabled = -1;
398 static bool power_off;
400 static bool power_off = 1;
402 static bool realmode_power_off;
403 #ifdef CONFIG_APM_ALLOW_INTS
404 static bool allow_ints = 1;
406 static bool allow_ints;
408 static bool broken_psr;
410 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
411 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
412 static struct apm_user *user_list;
413 static DEFINE_SPINLOCK(user_list_lock);
414 static DEFINE_MUTEX(apm_mutex);
417 * Set up a segment that references the real mode segment 0x40
418 * that extends up to the end of page zero (that we have reserved).
419 * This is for buggy BIOS's that refer to (real mode) segment 0x40
420 * even though they are called in protected mode.
422 static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
423 (unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
425 static const char driver_version[] = "1.16ac"; /* no spaces */
427 static struct task_struct *kapmd_task;
430 * APM event names taken from the APM 1.2 specification. These are
431 * the message codes that the BIOS uses to tell us about events
433 static const char * const apm_event_name[] = {
439 "power status change",
444 "system standby resume",
445 "capabilities change"
447 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
449 typedef struct lookup_t {
455 * The BIOS returns a set of standard error codes in AX when the
459 static const lookup_t error_table[] = {
460 /* N/A { APM_SUCCESS, "Operation succeeded" }, */
461 { APM_DISABLED, "Power management disabled" },
462 { APM_CONNECTED, "Real mode interface already connected" },
463 { APM_NOT_CONNECTED, "Interface not connected" },
464 { APM_16_CONNECTED, "16 bit interface already connected" },
465 /* N/A { APM_16_UNSUPPORTED, "16 bit interface not supported" }, */
466 { APM_32_CONNECTED, "32 bit interface already connected" },
467 { APM_32_UNSUPPORTED, "32 bit interface not supported" },
468 { APM_BAD_DEVICE, "Unrecognized device ID" },
469 { APM_BAD_PARAM, "Parameter out of range" },
470 { APM_NOT_ENGAGED, "Interface not engaged" },
471 { APM_BAD_FUNCTION, "Function not supported" },
472 { APM_RESUME_DISABLED, "Resume timer disabled" },
473 { APM_BAD_STATE, "Unable to enter requested state" },
474 /* N/A { APM_NO_EVENTS, "No events pending" }, */
475 { APM_NO_ERROR, "BIOS did not set a return code" },
476 { APM_NOT_PRESENT, "No APM present" }
478 #define ERROR_COUNT ARRAY_SIZE(error_table)
481 * apm_error - display an APM error
482 * @str: information string
483 * @err: APM BIOS return code
485 * Write a meaningful log entry to the kernel log in the event of
486 * an APM error. Note that this also handles (negative) kernel errors.
489 static void apm_error(char *str, int err)
493 for (i = 0; i < ERROR_COUNT; i++)
494 if (error_table[i].key == err)
497 pr_notice("%s: %s\n", str, error_table[i].msg);
499 pr_notice("%s: linux error code %i\n", str, err);
501 pr_notice("%s: unknown error code %#2.2x\n",
506 * These are the actual BIOS calls. Depending on APM_ZERO_SEGS and
507 * apm_info.allow_ints, we are being really paranoid here! Not only
508 * are interrupts disabled, but all the segment registers (except SS)
509 * are saved and zeroed this means that if the BIOS tries to reference
510 * any data without explicitly loading the segment registers, the kernel
511 * will fault immediately rather than have some unforeseen circumstances
512 * for the rest of the kernel. And it will be very obvious! :-) Doing
513 * this depends on CS referring to the same physical memory as DS so that
514 * DS can be zeroed before the call. Unfortunately, we can't do anything
515 * about the stack segment/pointer. Also, we tell the compiler that
516 * everything could change.
518 * Also, we KNOW that for the non error case of apm_bios_call, there
519 * is no useful data returned in the low order 8 bits of eax.
522 static inline unsigned long __apm_irq_save(void)
525 local_save_flags(flags);
526 if (apm_info.allow_ints) {
527 if (irqs_disabled_flags(flags))
535 #define apm_irq_save(flags) \
536 do { flags = __apm_irq_save(); } while (0)
538 static inline void apm_irq_restore(unsigned long flags)
540 if (irqs_disabled_flags(flags))
542 else if (irqs_disabled())
547 # define APM_DECL_SEGS \
548 unsigned int saved_fs; unsigned int saved_gs;
549 # define APM_DO_SAVE_SEGS \
550 savesegment(fs, saved_fs); savesegment(gs, saved_gs)
551 # define APM_DO_RESTORE_SEGS \
552 loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
554 # define APM_DECL_SEGS
555 # define APM_DO_SAVE_SEGS
556 # define APM_DO_RESTORE_SEGS
559 struct apm_bios_call {
569 /* Error: -ENOMEM, or bits 8-15 of eax */
574 * __apm_bios_call - Make an APM BIOS 32bit call
575 * @_call: pointer to struct apm_bios_call.
577 * Make an APM call using the 32bit protected mode interface. The
578 * caller is responsible for knowing if APM BIOS is configured and
579 * enabled. This call can disable interrupts for a long period of
580 * time on some laptops. The return value is in AH and the carry
581 * flag is loaded into AL. If there is an error, then the error
582 * code is returned in AH (bits 8-15 of eax) and this function
585 * Note: this makes the call on the current CPU.
587 static long __apm_bios_call(void *_call)
592 struct desc_struct save_desc_40;
593 struct desc_struct *gdt;
594 struct apm_bios_call *call = _call;
598 gdt = get_cpu_gdt_rw(cpu);
599 save_desc_40 = gdt[0x40 / 8];
600 gdt[0x40 / 8] = bad_bios_desc;
603 firmware_restrict_branch_speculation_start();
605 apm_bios_call_asm(call->func, call->ebx, call->ecx,
606 &call->eax, &call->ebx, &call->ecx, &call->edx,
609 firmware_restrict_branch_speculation_end();
610 apm_irq_restore(flags);
611 gdt[0x40 / 8] = save_desc_40;
614 return call->eax & 0xff;
617 /* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
618 static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
622 /* Don't bother with work_on_cpu in the common case, so we don't
623 * have to worry about OOM or overhead. */
624 if (get_cpu() == 0) {
629 ret = work_on_cpu(0, fn, call);
632 /* work_on_cpu can fail with -ENOMEM */
636 call->err = (call->eax >> 8) & 0xff;
642 * apm_bios_call - Make an APM BIOS 32bit call (on CPU 0)
643 * @call: the apm_bios_call registers.
645 * If there is an error, it is returned in @call.err.
647 static int apm_bios_call(struct apm_bios_call *call)
649 return on_cpu0(__apm_bios_call, call);
653 * __apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
654 * @_call: pointer to struct apm_bios_call.
656 * Make a BIOS call that returns one value only, or just status.
657 * If there is an error, then the error code is returned in AH
658 * (bits 8-15 of eax) and this function returns non-zero (it can
659 * also return -ENOMEM). This is used for simpler BIOS operations.
660 * This call may hold interrupts off for a long time on some laptops.
662 * Note: this makes the call on the current CPU.
664 static long __apm_bios_call_simple(void *_call)
670 struct desc_struct save_desc_40;
671 struct desc_struct *gdt;
672 struct apm_bios_call *call = _call;
676 gdt = get_cpu_gdt_rw(cpu);
677 save_desc_40 = gdt[0x40 / 8];
678 gdt[0x40 / 8] = bad_bios_desc;
681 firmware_restrict_branch_speculation_start();
683 error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
686 firmware_restrict_branch_speculation_end();
687 apm_irq_restore(flags);
688 gdt[0x40 / 8] = save_desc_40;
694 * apm_bios_call_simple - make a simple APM BIOS 32bit call
695 * @func: APM function to invoke
696 * @ebx_in: EBX register value for BIOS call
697 * @ecx_in: ECX register value for BIOS call
698 * @eax: EAX register on return from the BIOS call
701 * Make a BIOS call that returns one value only, or just status.
702 * If there is an error, then the error code is returned in @err
703 * and this function returns non-zero. This is used for simpler
704 * BIOS operations. This call may hold interrupts off for a long
705 * time on some laptops.
707 static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
710 struct apm_bios_call call;
717 ret = on_cpu0(__apm_bios_call_simple, &call);
724 * apm_driver_version - APM driver version
725 * @val: loaded with the APM version on return
727 * Retrieve the APM version supported by the BIOS. This is only
728 * supported for APM 1.1 or higher. An error indicates APM 1.0 is
731 * On entry val should point to a value indicating the APM driver
732 * version with the high byte being the major and the low byte the
733 * minor number both in BCD
735 * On return it will hold the BIOS revision supported in the
739 static int apm_driver_version(u_short *val)
744 if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
751 * apm_get_event - get an APM event from the BIOS
752 * @event: pointer to the event
753 * @info: point to the event information
755 * The APM BIOS provides a polled information for event
756 * reporting. The BIOS expects to be polled at least every second
757 * when events are pending. When a message is found the caller should
758 * poll until no more messages are present. However, this causes
759 * problems on some laptops where a suspend event notification is
760 * not cleared until it is acknowledged.
762 * Additional information is returned in the info pointer, providing
763 * that APM 1.2 is in use. If no messges are pending the value 0x80
764 * is returned (No power management events pending).
766 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
768 struct apm_bios_call call;
770 call.func = APM_FUNC_GET_EVENT;
771 call.ebx = call.ecx = 0;
773 if (apm_bios_call(&call))
777 if (apm_info.connection_version < 0x0102)
778 *info = ~0; /* indicate info not valid */
785 * set_power_state - set the power management state
786 * @what: which items to transition
787 * @state: state to transition to
789 * Request an APM change of state for one or more system devices. The
790 * processor state must be transitioned last of all. what holds the
791 * class of device in the upper byte and the device number (0xFF for
792 * all) for the object to be transitioned.
794 * The state holds the state to transition to, which may in fact
795 * be an acceptance of a BIOS requested state change.
798 static int set_power_state(u_short what, u_short state)
803 if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
809 * set_system_power_state - set system wide power state
810 * @state: which state to enter
812 * Transition the entire system into a new APM power state.
815 static int set_system_power_state(u_short state)
817 return set_power_state(APM_DEVICE_ALL, state);
821 * apm_do_idle - perform power saving
823 * This function notifies the BIOS that the processor is (in the view
824 * of the OS) idle. It returns -1 in the event that the BIOS refuses
825 * to handle the idle request. On a success the function returns 1
826 * if the BIOS did clock slowing or 0 otherwise.
829 static int apm_do_idle(void)
836 if (!need_resched()) {
838 ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
845 static unsigned long t;
847 /* This always fails on some SMP boards running UP kernels.
848 * Only report the failure the first 5 times.
851 printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
856 clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
861 * apm_do_busy - inform the BIOS the CPU is busy
863 * Request that the BIOS brings the CPU back to full performance.
866 static void apm_do_busy(void)
871 if (clock_slowed || ALWAYS_CALL_BUSY) {
872 (void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
878 * If no process has really been interested in
879 * the CPU for some time, we want to call BIOS
880 * power management - we probably want
883 #define IDLE_CALC_LIMIT (HZ * 100)
884 #define IDLE_LEAKY_MAX 16
887 * apm_cpu_idle - cpu idling for APM capable Linux
889 * This is the idling function the kernel executes when APM is available. It
890 * tries to do BIOS powermanagement based on the average system idle time.
891 * Furthermore it calls the system default idle routine.
894 static int apm_cpu_idle(struct cpuidle_device *dev,
895 struct cpuidle_driver *drv, int index)
897 static int use_apm_idle; /* = 0 */
898 static unsigned int last_jiffies; /* = 0 */
899 static u64 last_stime; /* = 0 */
902 int apm_idle_done = 0;
903 unsigned int jiffies_since_last_check = jiffies - last_jiffies;
907 task_cputime(current, &utime, &stime);
908 if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
910 } else if (jiffies_since_last_check > idle_period) {
911 unsigned int idle_percentage;
913 idle_percentage = nsecs_to_jiffies(stime - last_stime);
914 idle_percentage *= 100;
915 idle_percentage /= jiffies_since_last_check;
916 use_apm_idle = (idle_percentage > idle_threshold);
917 if (apm_info.forbid_idle)
921 last_jiffies = jiffies;
924 bucket = IDLE_LEAKY_MAX;
926 while (!need_resched()) {
931 switch (apm_do_idle()) {
936 bucket = IDLE_LEAKY_MAX;
947 default: /* BIOS refused */
953 jiffies_since_last_check = jiffies - last_jiffies;
954 if (jiffies_since_last_check > idle_period)
965 * apm_power_off - ask the BIOS to power off
967 * Handle the power off sequence. This is the one piece of code we
968 * will execute even on SMP machines. In order to deal with BIOS
969 * bugs we support real mode APM BIOS power off calls. We also make
970 * the SMP call on CPU0 as some systems will only honour this call
971 * on their first cpu.
974 static void apm_power_off(void)
976 /* Some bioses don't like being called from CPU != 0 */
977 if (apm_info.realmode_power_off) {
978 set_cpus_allowed_ptr(current, cpumask_of(0));
979 machine_real_restart(MRR_APM);
981 (void)set_system_power_state(APM_STATE_OFF);
985 #ifdef CONFIG_APM_DO_ENABLE
988 * apm_enable_power_management - enable BIOS APM power management
989 * @enable: enable yes/no
991 * Enable or disable the APM BIOS power services.
994 static int apm_enable_power_management(int enable)
999 if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1000 return APM_NOT_ENGAGED;
1001 if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1002 enable, &eax, &err))
1005 apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1007 apm_info.bios.flags |= APM_BIOS_DISABLED;
1013 * apm_get_power_status - get current power state
1014 * @status: returned status
1015 * @bat: battery info
1016 * @life: estimated life
1018 * Obtain the current power status from the APM BIOS. We return a
1019 * status which gives the rough battery status, and current power
1020 * source. The bat value returned give an estimate as a percentage
1021 * of life and a status value for the battery. The estimated life
1022 * if reported is a lifetime in secodnds/minutes at current powwer
1026 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1028 struct apm_bios_call call;
1030 call.func = APM_FUNC_GET_STATUS;
1031 call.ebx = APM_DEVICE_ALL;
1034 if (apm_info.get_power_status_broken)
1035 return APM_32_UNSUPPORTED;
1036 if (apm_bios_call(&call)) {
1038 return APM_NO_ERROR;
1043 if (apm_info.get_power_status_swabinminutes) {
1044 *life = swab16((u16)call.edx);
1052 static int apm_get_battery_status(u_short which, u_short *status,
1053 u_short *bat, u_short *life, u_short *nbat)
1061 if (apm_info.connection_version < 0x0102) {
1062 /* pretend we only have one battery. */
1064 return APM_BAD_DEVICE;
1066 return apm_get_power_status(status, bat, life);
1069 if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1070 &ebx, &ecx, &edx, &esi))
1071 return (eax >> 8) & 0xff;
1081 * apm_engage_power_management - enable PM on a device
1082 * @device: identity of device
1085 * Activate or deactivate power management on either a specific device
1086 * or the entire system (%APM_DEVICE_ALL).
1089 static int apm_engage_power_management(u_short device, int enable)
1094 if ((enable == 0) && (device == APM_DEVICE_ALL)
1095 && (apm_info.bios.flags & APM_BIOS_DISABLED))
1096 return APM_DISABLED;
1097 if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1100 if (device == APM_DEVICE_ALL) {
1102 apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1104 apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1109 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1112 * apm_console_blank - blank the display
1115 * Attempt to blank the console, firstly by blanking just video device
1116 * zero, and if that fails (some BIOSes don't support it) then it blanks
1117 * all video devices. Typically the BIOS will do laptop backlight and
1118 * monitor powerdown for us.
1121 static int apm_console_blank(int blank)
1123 int error = APM_NOT_ENGAGED; /* silence gcc */
1126 static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1128 state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1130 for (i = 0; i < ARRAY_SIZE(dev); i++) {
1131 error = set_power_state(dev[i], state);
1133 if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1136 if (error == APM_NOT_ENGAGED)
1140 if (error == APM_NOT_ENGAGED) {
1144 eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1146 apm_error("set display", error);
1147 apm_error("engage interface", eng_error);
1150 return apm_console_blank(blank);
1153 apm_error("set display", error);
1158 static int queue_empty(struct apm_user *as)
1160 return as->event_head == as->event_tail;
1163 static apm_event_t get_queued_event(struct apm_user *as)
1165 if (++as->event_tail >= APM_MAX_EVENTS)
1167 return as->events[as->event_tail];
1170 static void queue_event(apm_event_t event, struct apm_user *sender)
1172 struct apm_user *as;
1174 spin_lock(&user_list_lock);
1175 if (user_list == NULL)
1177 for (as = user_list; as != NULL; as = as->next) {
1178 if ((as == sender) || (!as->reader))
1180 if (++as->event_head >= APM_MAX_EVENTS)
1183 if (as->event_head == as->event_tail) {
1184 static int notified;
1186 if (notified++ == 0)
1187 pr_err("an event queue overflowed\n");
1188 if (++as->event_tail >= APM_MAX_EVENTS)
1191 as->events[as->event_head] = event;
1192 if (!as->suser || !as->writer)
1195 case APM_SYS_SUSPEND:
1196 case APM_USER_SUSPEND:
1197 as->suspends_pending++;
1201 case APM_SYS_STANDBY:
1202 case APM_USER_STANDBY:
1203 as->standbys_pending++;
1208 wake_up_interruptible(&apm_waitqueue);
1210 spin_unlock(&user_list_lock);
1213 static void reinit_timer(void)
1215 #ifdef INIT_TIMER_AFTER_SUSPEND
1216 unsigned long flags;
1218 raw_spin_lock_irqsave(&i8253_lock, flags);
1219 /* set the clock to HZ */
1220 outb_p(0x34, PIT_MODE); /* binary, mode 2, LSB/MSB, ch 0 */
1222 outb_p(LATCH & 0xff, PIT_CH0); /* LSB */
1224 outb_p(LATCH >> 8, PIT_CH0); /* MSB */
1226 raw_spin_unlock_irqrestore(&i8253_lock, flags);
1230 static int suspend(int vetoable)
1233 struct apm_user *as;
1235 dpm_suspend_start(PMSG_SUSPEND);
1236 dpm_suspend_end(PMSG_SUSPEND);
1238 local_irq_disable();
1243 save_processor_state();
1244 err = set_system_power_state(APM_STATE_SUSPEND);
1245 ignore_normal_resume = 1;
1246 restore_processor_state();
1248 local_irq_disable();
1251 if (err == APM_NO_ERROR)
1253 if (err != APM_SUCCESS)
1254 apm_error("suspend", err);
1255 err = (err == APM_SUCCESS) ? 0 : -EIO;
1260 dpm_resume_start(PMSG_RESUME);
1261 dpm_resume_end(PMSG_RESUME);
1263 queue_event(APM_NORMAL_RESUME, NULL);
1264 spin_lock(&user_list_lock);
1265 for (as = user_list; as != NULL; as = as->next) {
1266 as->suspend_wait = 0;
1267 as->suspend_result = err;
1269 spin_unlock(&user_list_lock);
1270 wake_up_interruptible(&apm_suspend_waitqueue);
1274 static void standby(void)
1278 dpm_suspend_end(PMSG_SUSPEND);
1280 local_irq_disable();
1284 err = set_system_power_state(APM_STATE_STANDBY);
1285 if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1286 apm_error("standby", err);
1288 local_irq_disable();
1292 dpm_resume_start(PMSG_RESUME);
1295 static apm_event_t get_event(void)
1298 apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1299 apm_eventinfo_t info;
1301 static int notified;
1303 /* we don't use the eventinfo */
1304 error = apm_get_event(&event, &info);
1305 if (error == APM_SUCCESS)
1308 if ((error != APM_NO_EVENTS) && (notified++ == 0))
1309 apm_error("get_event", error);
1314 static void check_events(void)
1317 static unsigned long last_resume;
1318 static int ignore_bounce;
1320 while ((event = get_event()) != 0) {
1322 if (event <= NR_APM_EVENT_NAME)
1323 printk(KERN_DEBUG "apm: received %s notify\n",
1324 apm_event_name[event - 1]);
1326 printk(KERN_DEBUG "apm: received unknown "
1327 "event 0x%02x\n", event);
1330 && (time_after(jiffies, last_resume + bounce_interval)))
1334 case APM_SYS_STANDBY:
1335 case APM_USER_STANDBY:
1336 queue_event(event, NULL);
1337 if (standbys_pending <= 0)
1341 case APM_USER_SUSPEND:
1342 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1343 if (apm_info.connection_version > 0x100)
1344 set_system_power_state(APM_STATE_REJECT);
1347 case APM_SYS_SUSPEND:
1348 if (ignore_bounce) {
1349 if (apm_info.connection_version > 0x100)
1350 set_system_power_state(APM_STATE_REJECT);
1354 * If we are already processing a SUSPEND,
1355 * then further SUSPEND events from the BIOS
1356 * will be ignored. We also return here to
1357 * cope with the fact that the Thinkpads keep
1358 * sending a SUSPEND event until something else
1361 if (ignore_sys_suspend)
1363 ignore_sys_suspend = 1;
1364 queue_event(event, NULL);
1365 if (suspends_pending <= 0)
1369 case APM_NORMAL_RESUME:
1370 case APM_CRITICAL_RESUME:
1371 case APM_STANDBY_RESUME:
1372 ignore_sys_suspend = 0;
1373 last_resume = jiffies;
1375 if ((event != APM_NORMAL_RESUME)
1376 || (ignore_normal_resume == 0)) {
1377 dpm_resume_end(PMSG_RESUME);
1378 queue_event(event, NULL);
1380 ignore_normal_resume = 0;
1383 case APM_CAPABILITY_CHANGE:
1384 case APM_LOW_BATTERY:
1385 case APM_POWER_STATUS_CHANGE:
1386 queue_event(event, NULL);
1387 /* If needed, notify drivers here */
1390 case APM_UPDATE_TIME:
1393 case APM_CRITICAL_SUSPEND:
1395 * We are not allowed to reject a critical suspend.
1403 static void apm_event_handler(void)
1405 static int pending_count = 4;
1408 if ((standbys_pending > 0) || (suspends_pending > 0)) {
1409 if ((apm_info.connection_version > 0x100) &&
1410 (pending_count-- <= 0)) {
1413 printk(KERN_DEBUG "apm: setting state busy\n");
1414 err = set_system_power_state(APM_STATE_BUSY);
1416 apm_error("busy", err);
1424 * This is the APM thread main loop.
1427 static void apm_mainloop(void)
1429 DECLARE_WAITQUEUE(wait, current);
1431 add_wait_queue(&apm_waitqueue, &wait);
1432 set_current_state(TASK_INTERRUPTIBLE);
1434 schedule_timeout(APM_CHECK_TIMEOUT);
1435 if (kthread_should_stop())
1438 * Ok, check all events, check for idle (and mark us sleeping
1439 * so as not to count towards the load average)..
1441 set_current_state(TASK_INTERRUPTIBLE);
1442 apm_event_handler();
1444 remove_wait_queue(&apm_waitqueue, &wait);
1447 static int check_apm_user(struct apm_user *as, const char *func)
1449 if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1450 pr_err("%s passed bad filp\n", func);
1456 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1458 struct apm_user *as;
1462 as = fp->private_data;
1463 if (check_apm_user(as, "read"))
1465 if ((int)count < sizeof(apm_event_t))
1467 if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1469 wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1471 while ((i >= sizeof(event)) && !queue_empty(as)) {
1472 event = get_queued_event(as);
1473 if (copy_to_user(buf, &event, sizeof(event))) {
1479 case APM_SYS_SUSPEND:
1480 case APM_USER_SUSPEND:
1481 as->suspends_read++;
1484 case APM_SYS_STANDBY:
1485 case APM_USER_STANDBY:
1486 as->standbys_read++;
1489 buf += sizeof(event);
1494 if (signal_pending(current))
1495 return -ERESTARTSYS;
1499 static __poll_t do_poll(struct file *fp, poll_table *wait)
1501 struct apm_user *as;
1503 as = fp->private_data;
1504 if (check_apm_user(as, "poll"))
1506 poll_wait(fp, &apm_waitqueue, wait);
1507 if (!queue_empty(as))
1508 return EPOLLIN | EPOLLRDNORM;
1512 static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1514 struct apm_user *as;
1517 as = filp->private_data;
1518 if (check_apm_user(as, "ioctl"))
1520 if (!as->suser || !as->writer)
1523 case APM_IOC_STANDBY:
1524 mutex_lock(&apm_mutex);
1525 if (as->standbys_read > 0) {
1526 as->standbys_read--;
1527 as->standbys_pending--;
1530 queue_event(APM_USER_STANDBY, as);
1531 if (standbys_pending <= 0)
1533 mutex_unlock(&apm_mutex);
1535 case APM_IOC_SUSPEND:
1536 mutex_lock(&apm_mutex);
1537 if (as->suspends_read > 0) {
1538 as->suspends_read--;
1539 as->suspends_pending--;
1542 queue_event(APM_USER_SUSPEND, as);
1543 if (suspends_pending <= 0) {
1545 mutex_unlock(&apm_mutex);
1547 as->suspend_wait = 1;
1548 mutex_unlock(&apm_mutex);
1549 wait_event_interruptible(apm_suspend_waitqueue,
1550 as->suspend_wait == 0);
1551 ret = as->suspend_result;
1560 static int do_release(struct inode *inode, struct file *filp)
1562 struct apm_user *as;
1564 as = filp->private_data;
1565 if (check_apm_user(as, "release"))
1567 filp->private_data = NULL;
1568 if (as->standbys_pending > 0) {
1569 standbys_pending -= as->standbys_pending;
1570 if (standbys_pending <= 0)
1573 if (as->suspends_pending > 0) {
1574 suspends_pending -= as->suspends_pending;
1575 if (suspends_pending <= 0)
1578 spin_lock(&user_list_lock);
1579 if (user_list == as)
1580 user_list = as->next;
1582 struct apm_user *as1;
1584 for (as1 = user_list;
1585 (as1 != NULL) && (as1->next != as);
1589 pr_err("filp not in user list\n");
1591 as1->next = as->next;
1593 spin_unlock(&user_list_lock);
1598 static int do_open(struct inode *inode, struct file *filp)
1600 struct apm_user *as;
1602 as = kmalloc(sizeof(*as), GFP_KERNEL);
1606 as->magic = APM_BIOS_MAGIC;
1607 as->event_tail = as->event_head = 0;
1608 as->suspends_pending = as->standbys_pending = 0;
1609 as->suspends_read = as->standbys_read = 0;
1611 * XXX - this is a tiny bit broken, when we consider BSD
1612 * process accounting. If the device is opened by root, we
1613 * instantly flag that we used superuser privs. Who knows,
1614 * we might close the device immediately without doing a
1615 * privileged operation -- cevans
1617 as->suser = capable(CAP_SYS_ADMIN);
1618 as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1619 as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1620 spin_lock(&user_list_lock);
1621 as->next = user_list;
1623 spin_unlock(&user_list_lock);
1624 filp->private_data = as;
1628 #ifdef CONFIG_PROC_FS
1629 static int proc_apm_show(struct seq_file *m, void *v)
1635 unsigned short ac_line_status = 0xff;
1636 unsigned short battery_status = 0xff;
1637 unsigned short battery_flag = 0xff;
1638 int percentage = -1;
1639 int time_units = -1;
1642 if ((num_online_cpus() == 1) &&
1643 !(error = apm_get_power_status(&bx, &cx, &dx))) {
1644 ac_line_status = (bx >> 8) & 0xff;
1645 battery_status = bx & 0xff;
1646 if ((cx & 0xff) != 0xff)
1647 percentage = cx & 0xff;
1649 if (apm_info.connection_version > 0x100) {
1650 battery_flag = (cx >> 8) & 0xff;
1652 units = (dx & 0x8000) ? "min" : "sec";
1653 time_units = dx & 0x7fff;
1657 /* Arguments, with symbols from linux/apm_bios.h. Information is
1658 from the Get Power Status (0x0a) call unless otherwise noted.
1660 0) Linux driver version (this will change if format changes)
1661 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2.
1662 2) APM flags from APM Installation Check (0x00):
1663 bit 0: APM_16_BIT_SUPPORT
1664 bit 1: APM_32_BIT_SUPPORT
1665 bit 2: APM_IDLE_SLOWS_CLOCK
1666 bit 3: APM_BIOS_DISABLED
1667 bit 4: APM_BIOS_DISENGAGED
1671 0x02: On backup power (BIOS >= 1.1 only)
1678 0x04: Selected battery not present (BIOS >= 1.2 only)
1685 bit 7: No system battery
1687 6) Remaining battery life (percentage of charge):
1690 7) Remaining battery life (time units):
1691 Number of remaining minutes or seconds
1693 8) min = minutes; sec = seconds */
1695 seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1697 (apm_info.bios.version >> 8) & 0xff,
1698 apm_info.bios.version & 0xff,
1699 apm_info.bios.flags,
1710 static int apm(void *unused)
1720 * This is to avoid random crashes at boot time during initialization
1721 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1722 * Some bioses don't like being called from CPU != 0.
1723 * Method suggested by Ingo Molnar.
1725 set_cpus_allowed_ptr(current, cpumask_of(0));
1726 BUG_ON(smp_processor_id() != 0);
1728 if (apm_info.connection_version == 0) {
1729 apm_info.connection_version = apm_info.bios.version;
1730 if (apm_info.connection_version > 0x100) {
1732 * We only support BIOSs up to version 1.2
1734 if (apm_info.connection_version > 0x0102)
1735 apm_info.connection_version = 0x0102;
1736 error = apm_driver_version(&apm_info.connection_version);
1737 if (error != APM_SUCCESS) {
1738 apm_error("driver version", error);
1739 /* Fall back to an APM 1.0 connection. */
1740 apm_info.connection_version = 0x100;
1746 printk(KERN_INFO "apm: Connection version %d.%d\n",
1747 (apm_info.connection_version >> 8) & 0xff,
1748 apm_info.connection_version & 0xff);
1750 #ifdef CONFIG_APM_DO_ENABLE
1751 if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1753 * This call causes my NEC UltraLite Versa 33/C to hang if it
1754 * is booted with PM disabled but not in the docking station.
1757 error = apm_enable_power_management(1);
1759 apm_error("enable power management", error);
1765 if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1766 && (apm_info.connection_version > 0x0100)) {
1767 error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1769 apm_error("engage power management", error);
1774 if (debug && (num_online_cpus() == 1 || smp)) {
1775 error = apm_get_power_status(&bx, &cx, &dx);
1777 printk(KERN_INFO "apm: power status not available\n");
1779 switch ((bx >> 8) & 0xff) {
1781 power_stat = "off line";
1784 power_stat = "on line";
1787 power_stat = "on backup power";
1790 power_stat = "unknown";
1793 switch (bx & 0xff) {
1801 bat_stat = "critical";
1804 bat_stat = "charging";
1807 bat_stat = "unknown";
1811 "apm: AC %s, battery status %s, battery life ",
1812 power_stat, bat_stat);
1813 if ((cx & 0xff) == 0xff)
1814 printk("unknown\n");
1816 printk("%d%%\n", cx & 0xff);
1817 if (apm_info.connection_version > 0x100) {
1819 "apm: battery flag 0x%02x, battery life ",
1822 printk("unknown\n");
1824 printk("%d %s\n", dx & 0x7fff,
1826 "minutes" : "seconds");
1831 /* Install our power off handler.. */
1833 pm_power_off = apm_power_off;
1835 if (num_online_cpus() == 1 || smp) {
1836 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1837 console_blank_hook = apm_console_blank;
1840 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1841 console_blank_hook = NULL;
1849 static int __init apm_setup(char *str)
1853 while ((str != NULL) && (*str != '\0')) {
1854 if (strncmp(str, "off", 3) == 0)
1856 if (strncmp(str, "on", 2) == 0)
1858 if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1859 (strncmp(str, "bounce_interval=", 16) == 0))
1860 bounce_interval = simple_strtol(str + 16, NULL, 0);
1861 if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1862 (strncmp(str, "idle_threshold=", 15) == 0))
1863 idle_threshold = simple_strtol(str + 15, NULL, 0);
1864 if ((strncmp(str, "idle-period=", 12) == 0) ||
1865 (strncmp(str, "idle_period=", 12) == 0))
1866 idle_period = simple_strtol(str + 12, NULL, 0);
1867 invert = (strncmp(str, "no-", 3) == 0) ||
1868 (strncmp(str, "no_", 3) == 0);
1871 if (strncmp(str, "debug", 5) == 0)
1873 if ((strncmp(str, "power-off", 9) == 0) ||
1874 (strncmp(str, "power_off", 9) == 0))
1875 power_off = !invert;
1876 if (strncmp(str, "smp", 3) == 0) {
1878 idle_threshold = 100;
1880 if ((strncmp(str, "allow-ints", 10) == 0) ||
1881 (strncmp(str, "allow_ints", 10) == 0))
1882 apm_info.allow_ints = !invert;
1883 if ((strncmp(str, "broken-psr", 10) == 0) ||
1884 (strncmp(str, "broken_psr", 10) == 0))
1885 apm_info.get_power_status_broken = !invert;
1886 if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1887 (strncmp(str, "realmode_power_off", 18) == 0))
1888 apm_info.realmode_power_off = !invert;
1889 str = strchr(str, ',');
1891 str += strspn(str, ", \t");
1896 __setup("apm=", apm_setup);
1899 static const struct file_operations apm_bios_fops = {
1900 .owner = THIS_MODULE,
1903 .unlocked_ioctl = do_ioctl,
1905 .release = do_release,
1906 .llseek = noop_llseek,
1909 static struct miscdevice apm_device = {
1916 /* Simple "print if true" callback */
1917 static int __init print_if_true(const struct dmi_system_id *d)
1919 printk("%s\n", d->ident);
1924 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1925 * disabled before the suspend. Linux used to get terribly confused by that.
1927 static int __init broken_ps2_resume(const struct dmi_system_id *d)
1929 printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1930 "workaround hopefully not needed.\n", d->ident);
1934 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1935 static int __init set_realmode_power_off(const struct dmi_system_id *d)
1937 if (apm_info.realmode_power_off == 0) {
1938 apm_info.realmode_power_off = 1;
1939 printk(KERN_INFO "%s bios detected. "
1940 "Using realmode poweroff only.\n", d->ident);
1945 /* Some laptops require interrupts to be enabled during APM calls */
1946 static int __init set_apm_ints(const struct dmi_system_id *d)
1948 if (apm_info.allow_ints == 0) {
1949 apm_info.allow_ints = 1;
1950 printk(KERN_INFO "%s machine detected. "
1951 "Enabling interrupts during APM calls.\n", d->ident);
1956 /* Some APM bioses corrupt memory or just plain do not work */
1957 static int __init apm_is_horked(const struct dmi_system_id *d)
1959 if (apm_info.disabled == 0) {
1960 apm_info.disabled = 1;
1961 printk(KERN_INFO "%s machine detected. "
1962 "Disabling APM.\n", d->ident);
1967 static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1969 if (apm_info.disabled == 0) {
1970 apm_info.disabled = 1;
1971 printk(KERN_INFO "%s machine detected. "
1972 "Disabling APM.\n", d->ident);
1973 printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1974 printk(KERN_INFO "download from support.intel.com\n");
1979 /* Some APM bioses hang on APM idle calls */
1980 static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1982 if (apm_info.forbid_idle == 0) {
1983 apm_info.forbid_idle = 1;
1984 printk(KERN_INFO "%s machine detected. "
1985 "Disabling APM idle calls.\n", d->ident);
1991 * Check for clue free BIOS implementations who use
1992 * the following QA technique
1994 * [ Write BIOS Code ]<------
1996 * < Does it Compile >----N--
1998 * < Does it Boot Win98 >-N--
2002 * Phoenix A04 08/24/2000 is known bad (Dell Inspiron 5000e)
2003 * Phoenix A07 09/29/2000 is known good (Dell Inspiron 5000)
2005 static int __init broken_apm_power(const struct dmi_system_id *d)
2007 apm_info.get_power_status_broken = 1;
2008 printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2009 "disabling power status reporting.\n");
2014 * This bios swaps the APM minute reporting bytes over (Many sony laptops
2015 * have this problem).
2017 static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2019 apm_info.get_power_status_swabinminutes = 1;
2020 printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2021 "in minutes and wrong byte order.\n");
2025 static const struct dmi_system_id apm_dmi_table[] __initconst = {
2028 KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2029 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2030 DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2032 { /* Handle problems with APM on the C600 */
2033 broken_ps2_resume, "Dell Latitude C600",
2034 { DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2035 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2037 { /* Allow interrupts during suspend on Dell Latitude laptops*/
2038 set_apm_ints, "Dell Latitude",
2039 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2040 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2043 apm_is_horked, "Dell Inspiron 2500",
2044 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2045 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2046 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2047 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2049 { /* Allow interrupts during suspend on Dell Inspiron laptops*/
2050 set_apm_ints, "Dell Inspiron", {
2051 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2052 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2054 { /* Handle problems with APM on Inspiron 5000e */
2055 broken_apm_power, "Dell Inspiron 5000e",
2056 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2057 DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2058 DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2060 { /* Handle problems with APM on Inspiron 2500 */
2061 broken_apm_power, "Dell Inspiron 2500",
2062 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2063 DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2064 DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2067 apm_is_horked, "Dell Dimension 4100",
2068 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2069 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2070 DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2071 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2073 { /* Allow interrupts during suspend on Compaq Laptops*/
2074 set_apm_ints, "Compaq 12XL125",
2075 { DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2076 DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2077 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2078 DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2080 { /* Allow interrupts during APM or the clock goes slow */
2081 set_apm_ints, "ASUSTeK",
2082 { DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2083 DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2085 { /* APM blows on shutdown */
2086 apm_is_horked, "ABIT KX7-333[R]",
2087 { DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2088 DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2091 apm_is_horked, "Trigem Delhi3",
2092 { DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2093 DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2096 apm_is_horked, "Fujitsu-Siemens",
2097 { DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2098 DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2101 apm_is_horked_d850md, "Intel D850MD",
2102 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2103 DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2106 apm_is_horked, "Intel D810EMO",
2107 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2108 DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2111 apm_is_horked, "Dell XPS-Z",
2112 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2113 DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2114 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2117 apm_is_horked, "Sharp PC-PJ/AX",
2118 { DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2119 DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2120 DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2121 DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2124 apm_is_horked, "Dell Inspiron 2500",
2125 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2126 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2127 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2128 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2130 { /* APM idle hangs */
2131 apm_likes_to_melt, "Jabil AMD",
2132 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2133 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2135 { /* APM idle hangs */
2136 apm_likes_to_melt, "AMI Bios",
2137 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2138 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2140 { /* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2141 swab_apm_power_in_minutes, "Sony VAIO",
2142 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2143 DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2144 DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2146 { /* Handle problems with APM on Sony Vaio PCG-N505VX */
2147 swab_apm_power_in_minutes, "Sony VAIO",
2148 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2149 DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2150 DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2152 { /* Handle problems with APM on Sony Vaio PCG-XG29 */
2153 swab_apm_power_in_minutes, "Sony VAIO",
2154 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2155 DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2156 DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2158 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2159 swab_apm_power_in_minutes, "Sony VAIO",
2160 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2161 DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2162 DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2164 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2165 swab_apm_power_in_minutes, "Sony VAIO",
2166 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2167 DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2168 DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2170 { /* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2171 swab_apm_power_in_minutes, "Sony VAIO",
2172 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2173 DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2174 DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2176 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2177 swab_apm_power_in_minutes, "Sony VAIO",
2178 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2179 DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2180 DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2182 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2183 swab_apm_power_in_minutes, "Sony VAIO",
2184 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2185 DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2186 DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2188 { /* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2189 swab_apm_power_in_minutes, "Sony VAIO",
2190 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2191 DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2192 DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2194 { /* Handle problems with APM on Sony Vaio PCG-F104K */
2195 swab_apm_power_in_minutes, "Sony VAIO",
2196 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2197 DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2198 DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2201 { /* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2202 swab_apm_power_in_minutes, "Sony VAIO",
2203 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2204 DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2205 DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2207 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2208 swab_apm_power_in_minutes, "Sony VAIO",
2209 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2210 DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2211 DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2213 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2214 swab_apm_power_in_minutes, "Sony VAIO",
2215 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2216 DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2217 DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2219 { /* broken PM poweroff bios */
2220 set_realmode_power_off, "Award Software v4.60 PGMA",
2221 { DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2222 DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2223 DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2226 /* Generic per vendor APM settings */
2228 { /* Allow interrupts during suspend on IBM laptops */
2229 set_apm_ints, "IBM",
2230 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2237 * Just start the APM thread. We do NOT want to do APM BIOS
2238 * calls from anything but the APM thread, if for no other reason
2239 * than the fact that we don't trust the APM BIOS. This way,
2240 * most common APM BIOS problems that lead to protection errors
2241 * etc will have at least some level of being contained...
2243 * In short, if something bad happens, at least we have a choice
2244 * of just killing the apm thread..
2246 static int __init apm_init(void)
2248 struct desc_struct *gdt;
2251 dmi_check_system(apm_dmi_table);
2253 if (apm_info.bios.version == 0 || machine_is_olpc()) {
2254 printk(KERN_INFO "apm: BIOS not found.\n");
2258 "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2259 ((apm_info.bios.version >> 8) & 0xff),
2260 (apm_info.bios.version & 0xff),
2261 apm_info.bios.flags,
2263 if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2264 printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2269 apm_info.allow_ints = 1;
2271 apm_info.get_power_status_broken = 1;
2272 if (realmode_power_off)
2273 apm_info.realmode_power_off = 1;
2274 /* User can override, but default is to trust DMI */
2275 if (apm_disabled != -1)
2276 apm_info.disabled = apm_disabled;
2279 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2280 * but is reportedly a 1.0 BIOS.
2282 if (apm_info.bios.version == 0x001)
2283 apm_info.bios.version = 0x100;
2285 /* BIOS < 1.2 doesn't set cseg_16_len */
2286 if (apm_info.bios.version < 0x102)
2287 apm_info.bios.cseg_16_len = 0; /* 64k */
2290 printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2291 apm_info.bios.cseg, apm_info.bios.offset,
2292 apm_info.bios.cseg_16, apm_info.bios.dseg);
2293 if (apm_info.bios.version > 0x100)
2294 printk(" cseg len %x, dseg len %x",
2295 apm_info.bios.cseg_len,
2296 apm_info.bios.dseg_len);
2297 if (apm_info.bios.version > 0x101)
2298 printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2302 if (apm_info.disabled) {
2303 pr_notice("disabled on user request.\n");
2306 if ((num_online_cpus() > 1) && !power_off && !smp) {
2307 pr_notice("disabled - APM is not SMP safe.\n");
2308 apm_info.disabled = 1;
2311 if (!acpi_disabled) {
2312 pr_notice("overridden by ACPI.\n");
2313 apm_info.disabled = 1;
2318 * Set up the long jump entry point to the APM BIOS, which is called
2319 * from inline assembly.
2321 apm_bios_entry.offset = apm_info.bios.offset;
2322 apm_bios_entry.segment = APM_CS;
2325 * The APM 1.1 BIOS is supposed to provide limit information that it
2326 * recognizes. Many machines do this correctly, but many others do
2327 * not restrict themselves to their claimed limit. When this happens,
2328 * they will cause a segmentation violation in the kernel at boot time.
2329 * Most BIOS's, however, will respect a 64k limit, so we use that.
2331 * Note we only set APM segments on CPU zero, since we pin the APM
2334 gdt = get_cpu_gdt_rw(0);
2335 set_desc_base(&gdt[APM_CS >> 3],
2336 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2337 set_desc_base(&gdt[APM_CS_16 >> 3],
2338 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2339 set_desc_base(&gdt[APM_DS >> 3],
2340 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2342 proc_create_single("apm", 0, NULL, proc_apm_show);
2344 kapmd_task = kthread_create(apm, NULL, "kapmd");
2345 if (IS_ERR(kapmd_task)) {
2346 pr_err("disabled - Unable to start kernel thread\n");
2347 err = PTR_ERR(kapmd_task);
2349 remove_proc_entry("apm", NULL);
2352 wake_up_process(kapmd_task);
2354 if (num_online_cpus() > 1 && !smp) {
2356 "apm: disabled - APM is not SMP safe (power off active).\n");
2361 * Note we don't actually care if the misc_device cannot be registered.
2362 * this driver can do its job without it, even if userspace can't
2363 * control it. just log the error
2365 if (misc_register(&apm_device))
2366 printk(KERN_WARNING "apm: Could not register misc device.\n");
2369 idle_period = (idle_period * HZ) / 100;
2370 if (idle_threshold < 100) {
2371 cpuidle_poll_state_init(&apm_idle_driver);
2372 if (!cpuidle_register_driver(&apm_idle_driver))
2373 if (cpuidle_register_device(&apm_cpuidle_device))
2374 cpuidle_unregister_driver(&apm_idle_driver);
2380 static void __exit apm_exit(void)
2384 cpuidle_unregister_device(&apm_cpuidle_device);
2385 cpuidle_unregister_driver(&apm_idle_driver);
2387 if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2388 && (apm_info.connection_version > 0x0100)) {
2389 error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2391 apm_error("disengage power management", error);
2393 misc_deregister(&apm_device);
2394 remove_proc_entry("apm", NULL);
2396 pm_power_off = NULL;
2398 kthread_stop(kapmd_task);
2403 module_init(apm_init);
2404 module_exit(apm_exit);
2406 MODULE_AUTHOR("Stephen Rothwell");
2407 MODULE_DESCRIPTION("Advanced Power Management");
2408 MODULE_LICENSE("GPL");
2409 module_param(debug, bool, 0644);
2410 MODULE_PARM_DESC(debug, "Enable debug mode");
2411 module_param(power_off, bool, 0444);
2412 MODULE_PARM_DESC(power_off, "Enable power off");
2413 module_param(bounce_interval, int, 0444);
2414 MODULE_PARM_DESC(bounce_interval,
2415 "Set the number of ticks to ignore suspend bounces");
2416 module_param(allow_ints, bool, 0444);
2417 MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2418 module_param(broken_psr, bool, 0444);
2419 MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2420 module_param(realmode_power_off, bool, 0444);
2421 MODULE_PARM_DESC(realmode_power_off,
2422 "Switch to real mode before powering off");
2423 module_param(idle_threshold, int, 0444);
2424 MODULE_PARM_DESC(idle_threshold,
2425 "System idle percentage above which to make APM BIOS idle calls");
2426 module_param(idle_period, int, 0444);
2427 MODULE_PARM_DESC(idle_period,
2428 "Period (in sec/100) over which to calculate the idle percentage");
2429 module_param(smp, bool, 0444);
2430 MODULE_PARM_DESC(smp,
2431 "Set this to enable APM use on an SMP platform. Use with caution on older systems");
2432 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);