bus.c

linux 内核源代码

/*
 *  acpi_bus.c - ACPI Bus Driver ($Revision: 80 $)
 *
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <[e-mail]>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or (at
 *  your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/sched.h>
#include <linux/pm.h>
#include <linux/device.h>
#include <linux/proc_fs.h>
#ifdef CONFIG_X86
#include <asm/mpspec.h>
#endif
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>

#define _COMPONENT		ACPI_BUS_COMPONENT
ACPI_MODULE_NAME("bus");
#ifdef	CONFIG_X86
extern void __init acpi_pic_sci_set_trigger(unsigned int irq, u16 trigger);
#endif

struct acpi_device *acpi_root;
struct proc_dir_entry *acpi_root_dir;
EXPORT_SYMBOL(acpi_root_dir);

#define STRUCT_TO_INT(s)	(*((int*)&s))

/* --------------------------------------------------------------------------
                                Device Management
   -------------------------------------------------------------------------- */

int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
{
	acpi_status status = AE_OK;


	if (!device)
		return -EINVAL;

	/* TBD: Support fixed-feature devices */

	status = acpi_get_data(handle, acpi_bus_data_handler, (void **)device);
	if (ACPI_FAILURE(status) || !*device) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
				  handle));
		return -ENODEV;
	}

	return 0;
}

EXPORT_SYMBOL(acpi_bus_get_device);

int acpi_bus_get_status(struct acpi_device *device)
{
	acpi_status status = AE_OK;
	unsigned long sta = 0;


	if (!device)
		return -EINVAL;

	/*
	 * Evaluate _STA if present.
	 */
	if (device->flags.dynamic_status) {
		status =
		    acpi_evaluate_integer(device->handle, "_STA", NULL, &sta);
		if (ACPI_FAILURE(status))
			return -ENODEV;
		STRUCT_TO_INT(device->status) = (int)sta;
	}

	/*
	 * Otherwise we assume the status of our parent (unless we don't
	 * have one, in which case status is implied).
	 */
	else if (device->parent)
		device->status = device->parent->status;
	else
		STRUCT_TO_INT(device->status) =
		    ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
		    ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;

	if (device->status.functional && !device->status.present) {
		printk(KERN_WARNING PREFIX "Device [%s] status [%08x]: "
		       "functional but not present; setting present\n",
		       device->pnp.bus_id, (u32) STRUCT_TO_INT(device->status));
		device->status.present = 1;
	}

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
			  device->pnp.bus_id,
			  (u32) STRUCT_TO_INT(device->status)));

	return 0;
}

EXPORT_SYMBOL(acpi_bus_get_status);

/* --------------------------------------------------------------------------
                                 Power Management
   -------------------------------------------------------------------------- */

int acpi_bus_get_power(acpi_handle handle, int *state)
{
	int result = 0;
	acpi_status status = 0;
	struct acpi_device *device = NULL;
	unsigned long psc = 0;


	result = acpi_bus_get_device(handle, &device);
	if (result)
		return result;

	*state = ACPI_STATE_UNKNOWN;

	if (!device->flags.power_manageable) {
		/* TBD: Non-recursive algorithm for walking up hierarchy */
		if (device->parent)
			*state = device->parent->power.state;
		else
			*state = ACPI_STATE_D0;
	} else {
		/*
		 * Get the device's power state either directly (via _PSC) or
		 * indirectly (via power resources).
		 */
		if (device->power.flags.explicit_get) {
			status = acpi_evaluate_integer(device->handle, "_PSC",
						       NULL, &psc);
			if (ACPI_FAILURE(status))
				return -ENODEV;
			device->power.state = (int)psc;
		} else if (device->power.flags.power_resources) {
			result = acpi_power_get_inferred_state(device);
			if (result)
				return result;
		}

		*state = device->power.state;
	}

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is D%d\n",
			  device->pnp.bus_id, device->power.state));

	return 0;
}

EXPORT_SYMBOL(acpi_bus_get_power);

int acpi_bus_set_power(acpi_handle handle, int state)
{
	int result = 0;
	acpi_status status = AE_OK;
	struct acpi_device *device = NULL;
	char object_name[5] = { '_', 'P', 'S', '0' + state, '\0' };


	result = acpi_bus_get_device(handle, &device);
	if (result)
		return result;

	if ((state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
		return -EINVAL;

	/* Make sure this is a valid target state */

	if (!device->flags.power_manageable) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device `[%s]' is not power manageable\n",
				kobject_name(&device->dev.kobj)));
		return -ENODEV;
	}
	/*
	 * Get device's current power state
	 */
	acpi_bus_get_power(device->handle, &device->power.state);
	if ((state == device->power.state) && !device->flags.force_power_state) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at D%d\n",
				  state));
		return 0;
	}

	if (!device->power.states[state].flags.valid) {
		printk(KERN_WARNING PREFIX "Device does not support D%d\n", state);
		return -ENODEV;
	}
	if (device->parent && (state < device->parent->power.state)) {
		printk(KERN_WARNING PREFIX
			      "Cannot set device to a higher-powered"
			      " state than parent\n");
		return -ENODEV;
	}

	/*
	 * Transition Power
	 * ----------------
	 * On transitions to a high-powered state we first apply power (via
	 * power resources) then evalute _PSx.  Conversly for transitions to
	 * a lower-powered state.
	 */
	if (state < device->power.state) {
		if (device->power.flags.power_resources) {
			result = acpi_power_transition(device, state);
			if (result)
				goto end;
		}
		if (device->power.states[state].flags.explicit_set) {
			status = acpi_evaluate_object(device->handle,
						      object_name, NULL, NULL);
			if (ACPI_FAILURE(status)) {
				result = -ENODEV;
				goto end;
			}
		}
	} else {
		if (device->power.states[state].flags.explicit_set) {
			status = acpi_evaluate_object(device->handle,
						      object_name, NULL, NULL);
			if (ACPI_FAILURE(status)) {
				result = -ENODEV;
				goto end;
			}
		}
		if (device->power.flags.power_resources) {
			result = acpi_power_transition(device, state);
			if (result)
				goto end;
		}
	}

      end:
	if (result)
		printk(KERN_WARNING PREFIX
			      "Transitioning device [%s] to D%d\n",
			      device->pnp.bus_id, state);
	else {
		device->power.state = state;
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				  "Device [%s] transitioned to D%d\n",
				  device->pnp.bus_id, state));
	}

	return result;
}

EXPORT_SYMBOL(acpi_bus_set_power);

/* --------------------------------------------------------------------------
                                Event Management
   -------------------------------------------------------------------------- */

#ifdef CONFIG_ACPI_PROC_EVENT
static DEFINE_SPINLOCK(acpi_bus_event_lock);

LIST_HEAD(acpi_bus_event_list);
DECLARE_WAIT_QUEUE_HEAD(acpi_bus_event_queue);

extern int event_is_open;

int acpi_bus_generate_proc_event4(const char *device_class, const char *bus_id, u8 type, int data)
{
	struct acpi_bus_event *event;
	unsigned long flags = 0;

	/* drop event on the floor if no one's listening */
	if (!event_is_open)
		return 0;

	event = kmalloc(sizeof(struct acpi_bus_event), GFP_ATOMIC);
	if (!event)
		return -ENOMEM;

	strcpy(event->device_class, device_class);
	strcpy(event->bus_id, bus_id);
	event->type = type;
	event->data = data;

	spin_lock_irqsave(&acpi_bus_event_lock, flags);
	list_add_tail(&event->node, &acpi_bus_event_list);
	spin_unlock_irqrestore(&acpi_bus_event_lock, flags);

	wake_up_interruptible(&acpi_bus_event_queue);

	return 0;

}

EXPORT_SYMBOL_GPL(acpi_bus_generate_proc_event4);

int acpi_bus_generate_proc_event(struct acpi_device *device, u8 type, int data)
{
	if (!device)
		return -EINVAL;
	return acpi_bus_generate_proc_event4(device->pnp.device_class,
					     device->pnp.bus_id, type, data);
}

EXPORT_SYMBOL(acpi_bus_generate_proc_event);

int acpi_bus_receive_event(struct acpi_bus_event *event)
{
	unsigned long flags = 0;
	struct acpi_bus_event *entry = NULL;

	DECLARE_WAITQUEUE(wait, current);


	if (!event)
		return -EINVAL;

	if (list_empty(&acpi_bus_event_list)) {

		set_current_state(TASK_INTERRUPTIBLE);
		add_wait_queue(&acpi_bus_event_queue, &wait);

		if (list_empty(&acpi_bus_event_list))
			schedule();

		remove_wait_queue(&acpi_bus_event_queue, &wait);
		set_current_state(TASK_RUNNING);

		if (signal_pending(current))
			return -ERESTARTSYS;
	}

	spin_lock_irqsave(&acpi_bus_event_lock, flags);
	entry =
	    list_entry(acpi_bus_event_list.next, struct acpi_bus_event, node);
	if (entry)
		list_del(&entry->node);
	spin_unlock_irqrestore(&acpi_bus_event_lock, flags);

	if (!entry)
		return -ENODEV;

	memcpy(event, entry, sizeof(struct acpi_bus_event));

	kfree(entry);

	return 0;
}

EXPORT_SYMBOL(acpi_bus_receive_event);
#endif	/* CONFIG_ACPI_PROC_EVENT */

/* --------------------------------------------------------------------------
                             Notification Handling
   -------------------------------------------------------------------------- */

static int
acpi_bus_check_device(struct acpi_device *device, int *status_changed)
{
	acpi_status status = 0;
	struct acpi_device_status old_status;


	if (!device)
		return -EINVAL;

	if (status_changed)
		*status_changed = 0;

	old_status = device->status;

	/*