apm_32.c

linux 内核源代码

		}
		if (original_pm_idle)
			original_pm_idle();
		else
			default_idle();
		jiffies_since_last_check = jiffies - last_jiffies;
		if (jiffies_since_last_check > idle_period)
			goto recalc;
	}

	if (apm_idle_done)
		apm_do_busy();
}

/**
 *	apm_power_off	-	ask the BIOS to power off
 *
 *	Handle the power off sequence. This is the one piece of code we
 *	will execute even on SMP machines. In order to deal with BIOS
 *	bugs we support real mode APM BIOS power off calls. We also make
 *	the SMP call on CPU0 as some systems will only honour this call
 *	on their first cpu.
 */
 
static void apm_power_off(void)
{
	unsigned char	po_bios_call[] = {
		0xb8, 0x00, 0x10,	/* movw  $0x1000,ax  */
		0x8e, 0xd0,		/* movw  ax,ss       */
		0xbc, 0x00, 0xf0,	/* movw  $0xf000,sp  */
		0xb8, 0x07, 0x53,	/* movw  $0x5307,ax  */
		0xbb, 0x01, 0x00,	/* movw  $0x0001,bx  */
		0xb9, 0x03, 0x00,	/* movw  $0x0003,cx  */
		0xcd, 0x15		/* int   $0x15       */
	};

	/* Some bioses don't like being called from CPU != 0 */
	if (apm_info.realmode_power_off)
	{
		(void)apm_save_cpus();
		machine_real_restart(po_bios_call, sizeof(po_bios_call));
	}
	else
		(void) set_system_power_state(APM_STATE_OFF);
}

#ifdef CONFIG_APM_DO_ENABLE

/**
 *	apm_enable_power_management - enable BIOS APM power management
 *	@enable: enable yes/no
 *
 *	Enable or disable the APM BIOS power services. 
 */
 
static int apm_enable_power_management(int enable)
{
	u32	eax;

	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
		return APM_NOT_ENGAGED;
	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
			enable, &eax))
		return (eax >> 8) & 0xff;
	if (enable)
		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
	else
		apm_info.bios.flags |= APM_BIOS_DISABLED;
	return APM_SUCCESS;
}
#endif

/**
 *	apm_get_power_status	-	get current power state
 *	@status: returned status
 *	@bat: battery info
 *	@life: estimated life
 *
 *	Obtain the current power status from the APM BIOS. We return a
 *	status which gives the rough battery status, and current power
 *	source. The bat value returned give an estimate as a percentage
 *	of life and a status value for the battery. The estimated life
 *	if reported is a lifetime in secodnds/minutes at current powwer
 *	consumption.
 */
 
static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
{
	u32	eax;
	u32	ebx;
	u32	ecx;
	u32	edx;
	u32	dummy;

	if (apm_info.get_power_status_broken)
		return APM_32_UNSUPPORTED;
	if (apm_bios_call(APM_FUNC_GET_STATUS, APM_DEVICE_ALL, 0,
			&eax, &ebx, &ecx, &edx, &dummy))
		return (eax >> 8) & 0xff;
	*status = ebx;
	*bat = ecx;
	if (apm_info.get_power_status_swabinminutes) {
		*life = swab16((u16)edx);
		*life |= 0x8000;
	} else
		*life = edx;
	return APM_SUCCESS;
}

#if 0
static int apm_get_battery_status(u_short which, u_short *status,
				  u_short *bat, u_short *life, u_short *nbat)
{
	u32	eax;
	u32	ebx;
	u32	ecx;
	u32	edx;
	u32	esi;

	if (apm_info.connection_version < 0x0102) {
		/* pretend we only have one battery. */
		if (which != 1)
			return APM_BAD_DEVICE;
		*nbat = 1;
		return apm_get_power_status(status, bat, life);
	}

	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
			&ebx, &ecx, &edx, &esi))
		return (eax >> 8) & 0xff;
	*status = ebx;
	*bat = ecx;
	*life = edx;
	*nbat = esi;
	return APM_SUCCESS;
}
#endif

/**
 *	apm_engage_power_management	-	enable PM on a device
 *	@device: identity of device
 *	@enable: on/off
 *
 *	Activate or deactive power management on either a specific device
 *	or the entire system (%APM_DEVICE_ALL).
 */
 
static int apm_engage_power_management(u_short device, int enable)
{
	u32	eax;

	if ((enable == 0) && (device == APM_DEVICE_ALL)
	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
		return APM_DISABLED;
	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable, &eax))
		return (eax >> 8) & 0xff;
	if (device == APM_DEVICE_ALL) {
		if (enable)
			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
		else
			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
	}
	return APM_SUCCESS;
}

#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)

/**
 *	apm_console_blank	-	blank the display
 *	@blank: on/off
 *
 *	Attempt to blank the console, firstly by blanking just video device
 *	zero, and if that fails (some BIOSes don't support it) then it blanks
 *	all video devices. Typically the BIOS will do laptop backlight and
 *	monitor powerdown for us.
 */
 
static int apm_console_blank(int blank)
{
	int error = APM_NOT_ENGAGED; /* silence gcc */
	int i;
	u_short state;
	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };

	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;

	for (i = 0; i < ARRAY_SIZE(dev); i++) {
		error = set_power_state(dev[i], state);

		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
			return 1;

		if (error == APM_NOT_ENGAGED)
			break;
	}

	if (error == APM_NOT_ENGAGED) {
		static int tried;
		int eng_error;
		if (tried++ == 0) {
			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
			if (eng_error) {
				apm_error("set display", error);
				apm_error("engage interface", eng_error);
				return 0;
			} else
				return apm_console_blank(blank);
		}
	}
	apm_error("set display", error);
	return 0;
}
#endif

static int queue_empty(struct apm_user *as)
{
	return as->event_head == as->event_tail;
}

static apm_event_t get_queued_event(struct apm_user *as)
{
	if (++as->event_tail >= APM_MAX_EVENTS)
		as->event_tail = 0;
	return as->events[as->event_tail];
}

static void queue_event(apm_event_t event, struct apm_user *sender)
{
	struct apm_user *	as;

	spin_lock(&user_list_lock);
	if (user_list == NULL)
		goto out;
	for (as = user_list; as != NULL; as = as->next) {
		if ((as == sender) || (!as->reader))
			continue;
		if (++as->event_head >= APM_MAX_EVENTS)
			as->event_head = 0;

		if (as->event_head == as->event_tail) {
			static int notified;

			if (notified++ == 0)
			    printk(KERN_ERR "apm: an event queue overflowed\n");
			if (++as->event_tail >= APM_MAX_EVENTS)
				as->event_tail = 0;
		}
		as->events[as->event_head] = event;
		if ((!as->suser) || (!as->writer))
			continue;
		switch (event) {
		case APM_SYS_SUSPEND:
		case APM_USER_SUSPEND:
			as->suspends_pending++;
			suspends_pending++;
			break;

		case APM_SYS_STANDBY:
		case APM_USER_STANDBY:
			as->standbys_pending++;
			standbys_pending++;
			break;
		}
	}
	wake_up_interruptible(&apm_waitqueue);
out:
	spin_unlock(&user_list_lock);
}

static void reinit_timer(void)
{
#ifdef INIT_TIMER_AFTER_SUSPEND
	unsigned long flags;

	spin_lock_irqsave(&i8253_lock, flags);
	/* set the clock to HZ */
	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
	udelay(10);
	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
	udelay(10);
	outb(LATCH >> 8, PIT_CH0);	/* MSB */
	udelay(10);
	spin_unlock_irqrestore(&i8253_lock, flags);
#endif
}

static int suspend(int vetoable)
{
	int		err;
	struct apm_user	*as;

	if (pm_send_all(PM_SUSPEND, (void *)3)) {
		/* Vetoed */
		if (vetoable) {
			if (apm_info.connection_version > 0x100)
				set_system_power_state(APM_STATE_REJECT);
			err = -EBUSY;
			ignore_sys_suspend = 0;
			printk(KERN_WARNING "apm: suspend was vetoed.\n");
			goto out;
		}
		printk(KERN_CRIT "apm: suspend was vetoed, but suspending anyway.\n");
	}

	device_suspend(PMSG_SUSPEND);
	local_irq_disable();
	device_power_down(PMSG_SUSPEND);

	local_irq_enable();

	save_processor_state();
	err = set_system_power_state(APM_STATE_SUSPEND);
	ignore_normal_resume = 1;
	restore_processor_state();

	local_irq_disable();
	reinit_timer();

	if (err == APM_NO_ERROR)
		err = APM_SUCCESS;
	if (err != APM_SUCCESS)
		apm_error("suspend", err);
	err = (err == APM_SUCCESS) ? 0 : -EIO;
	device_power_up();
	local_irq_enable();
	device_resume();
	pm_send_all(PM_RESUME, (void *)0);
	queue_event(APM_NORMAL_RESUME, NULL);
 out:
	spin_lock(&user_list_lock);
	for (as = user_list; as != NULL; as = as->next) {
		as->suspend_wait = 0;
		as->suspend_result = err;
	}
	spin_unlock(&user_list_lock);
	wake_up_interruptible(&apm_suspend_waitqueue);
	return err;
}

static void standby(void)
{
	int	err;

	local_irq_disable();
	device_power_down(PMSG_SUSPEND);
	local_irq_enable();

	err = set_system_power_state(APM_STATE_STANDBY);
	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
		apm_error("standby", err);

	local_irq_disable();
	device_power_up();
	local_irq_enable();
}

static apm_event_t get_event(void)
{
	int		error;
	apm_event_t	event = APM_NO_EVENTS; /* silence gcc */
	apm_eventinfo_t	info;

	static int notified;

	/* we don't use the eventinfo */
	error = apm_get_event(&event, &info);
	if (error == APM_SUCCESS)
		return event;

	if ((error != APM_NO_EVENTS) && (notified++ == 0))
		apm_error("get_event", error);

	return 0;
}

static void check_events(void)
{
	apm_event_t		event;
	static unsigned long	last_resume;
	static int		ignore_bounce;

	while ((event = get_event()) != 0) {
		if (debug) {
			if (event <= NR_APM_EVENT_NAME)
				printk(KERN_DEBUG "apm: received %s notify\n",
				       apm_event_name[event - 1]);
			else
				printk(KERN_DEBUG "apm: received unknown "
				       "event 0x%02x\n", event);
		}
		if (ignore_bounce
		    && ((jiffies - last_resume) > bounce_interval))
			ignore_bounce = 0;

		switch (event) {
		case APM_SYS_STANDBY:
		case APM_USER_STANDBY:
			queue_event(event, NULL);
			if (standbys_pending <= 0)
				standby();
			break;

		case APM_USER_SUSPEND:
#ifdef CONFIG_APM_IGNORE_USER_SUSPEND
			if (apm_info.connection_version > 0x100)
				set_system_power_state(APM_STATE_REJECT);
			break;
#endif
		case APM_SYS_SUSPEND:
			if (ignore_bounce) {
				if (apm_info.connection_version > 0x100)
					set_system_power_state(APM_STATE_REJECT);
				break;
			}
			/*
			 * If we are already processing a SUSPEND,
			 * then further SUSPEND events from the BIOS
			 * will be ignored.  We also return here to
			 * cope with the fact that the Thinkpads keep
			 * sending a SUSPEND event until something else
			 * happens!
			 */
			if (ignore_sys_suspend)
				return;
			ignore_sys_suspend = 1;
			queue_event(event, NULL);
			if (suspends_pending <= 0)
				(void) suspend(1);
			break;

		case APM_NORMAL_RESUME:
		case APM_CRITICAL_RESUME:
		case APM_STANDBY_RESUME:
			ignore_sys_suspend = 0;
			last_resume = jiffies;
			ignore_bounce = 1;
			if ((event != APM_NORMAL_RESUME)
			    || (ignore_normal_resume == 0)) {
				device_resume();
				pm_send_all(PM_RESUME, (void *)0);
				queue_event(event, NULL);
			}
			ignore_normal_resume = 0;
			break;

		case APM_CAPABILITY_CHANGE:
		case APM_LOW_BATTERY:
		case APM_POWER_STATUS_CHANGE:
			queue_event(event, NULL);
			/* If needed, notify drivers here */