patch-2.4.22 linux-2.4.22/drivers/acpi/bus.c

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diff -urN linux-2.4.21/drivers/acpi/bus.c linux-2.4.22/drivers/acpi/bus.c
@@ -0,0 +1,2092 @@
+/*
+ *  acpi_bus.c - ACPI Bus Driver ($Revision: 77 $)
+ *
+ *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  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/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/version.h>
+#include <linux/ioport.h>
+#include <linux/list.h>
+#include <linux/sched.h>
+#include <linux/pm.h>
+#include <linux/proc_fs.h>
+#ifdef CONFIG_X86
+#include <asm/mpspec.h>
+#endif
+#include <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+#include <acpi/acinterp.h>	/* for acpi_ex_eisa_id_to_string() */
+
+
+#define _COMPONENT		ACPI_BUS_COMPONENT
+ACPI_MODULE_NAME		("acpi_bus")
+
+MODULE_AUTHOR("Paul Diefenbaugh");
+MODULE_DESCRIPTION(ACPI_BUS_DRIVER_NAME);
+MODULE_LICENSE("GPL");
+
+#define	PREFIX			"ACPI: "
+
+extern void eisa_set_level_irq(unsigned int irq);
+
+extern int			acpi_disabled;
+
+FADT_DESCRIPTOR			acpi_fadt;
+struct acpi_device		*acpi_root;
+struct proc_dir_entry		*acpi_root_dir;
+
+#define STRUCT_TO_INT(s)	(*((int*)&s))
+
+
+/* --------------------------------------------------------------------------
+                          Linux Driver Model (LDM) Support
+   -------------------------------------------------------------------------- */
+
+#ifdef CONFIG_LDM
+
+static int acpi_device_probe(struct device *dev);
+static int acpi_device_remove(struct device *dev);
+static int acpi_device_suspend(struct device *dev, u32 state, u32 stage);
+static int acpi_device_resume(struct device *dev, u32 stage);
+
+static struct device_driver acpi_bus_driver = {
+	.probe = acpi_device_probe,
+	.remove = acpi_device_remove,	
+	.suspend = acpi_device_suspend,
+	.resume = acpi_device_resume,
+};
+
+
+static int
+acpi_device_probe (
+	struct device		*dev)
+{
+	ACPI_FUNCTION_TRACE("acpi_device_probe");
+
+	if (!dev)
+		return_VALUE(-EINVAL);
+
+	/* TBD */
+
+	return_VALUE(0);
+}
+
+
+static int
+acpi_device_remove (
+	struct device		*dev)
+{
+	ACPI_FUNCTION_TRACE("acpi_device_remove");
+
+	if (!dev)
+		return_VALUE(-EINVAL);
+
+	/* TBD */
+
+	return_VALUE(0);
+}
+
+
+static int
+acpi_device_suspend (
+	struct device		*dev,
+	u32			state,
+	u32			stage)
+{
+	ACPI_FUNCTION_TRACE("acpi_device_suspend");
+
+	if (!dev)
+		return_VALUE(-EINVAL);
+
+	/* TBD */
+
+	return_VALUE(0);
+}
+
+
+static int
+acpi_device_resume (
+	struct device		*dev,
+	u32			stage)
+{
+	ACPI_FUNCTION_TRACE("acpi_device_resume");
+
+	if (!dev)
+		return_VALUE(-EINVAL);
+
+	/* TBD */
+
+	return_VALUE(0);
+}
+
+#if 0 /* not used ATM */
+static int
+acpi_platform_add (
+	struct device		*dev)
+{
+	ACPI_FUNCTION_TRACE("acpi_platform_add");
+
+	if (!dev)
+		return -EINVAL;
+
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device %s (%s) added\n",
+		dev->name, dev->bus_id));
+
+	/* TBD */
+
+	return_VALUE(0);
+}
+
+
+static int
+acpi_platform_remove (
+	struct device		*dev)
+{
+	ACPI_FUNCTION_TRACE("acpi_platform_add");
+
+	if (!dev)
+		return -EINVAL;
+
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device %s (%s) removed\n",
+		dev->name, dev->bus_id));
+
+	/* TBD */
+
+	return_VALUE(0);
+}
+#endif /* unused */
+
+
+#endif /*CONFIG_LDM*/
+
+
+static int
+acpi_device_register (
+	struct acpi_device	*device,
+	struct acpi_device	*parent)
+{
+	int			result = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_device_register");
+
+	if (!device)
+		return_VALUE(-EINVAL);
+
+#ifdef CONFIG_LDM
+	sprintf(device->dev.name, "ACPI device %s:%s", 
+		device->pnp.hardware_id, device->pnp.unique_id);
+	strncpy(device->dev.bus_id, device->pnp.bus_id, sizeof(acpi_bus_id));
+	if (parent)
+		device->dev.parent = &parent->dev;
+	device->dev.driver = &acpi_bus_driver;
+
+	result = device_register(&device->dev);
+#endif /*CONFIG_LDM*/
+
+	return_VALUE(result);
+}
+
+
+static int
+acpi_device_unregister (
+	struct acpi_device	*device)
+{
+	ACPI_FUNCTION_TRACE("acpi_device_unregister");
+
+	if (!device)
+		return_VALUE(-EINVAL);
+
+#ifdef CONFIG_LDM
+	put_device(&device->dev);
+#endif /*CONFIG_LDM*/
+
+	return_VALUE(0);
+}
+
+
+/* --------------------------------------------------------------------------
+                                Device Management
+   -------------------------------------------------------------------------- */
+
+static void
+acpi_bus_data_handler (
+	acpi_handle		handle,
+	u32			function,
+	void			*context)
+{
+	ACPI_FUNCTION_TRACE("acpi_bus_data_handler");
+
+	/* TBD */
+
+	return_VOID;
+}
+
+
+int
+acpi_bus_get_device (
+	acpi_handle		handle,
+	struct acpi_device	**device)
+{
+	acpi_status		status = AE_OK;
+
+	ACPI_FUNCTION_TRACE("acpi_bus_get_device");
+
+	if (!device)
+		return_VALUE(-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_WARN, "Error getting context for object [%p]\n",
+			handle));
+		return_VALUE(-ENODEV);
+	}
+
+	return_VALUE(0);
+}
+
+int
+acpi_bus_get_status (
+	struct acpi_device	*device)
+{
+	acpi_status		status = AE_OK;
+	unsigned long		sta = 0;
+	
+	ACPI_FUNCTION_TRACE("acpi_bus_get_status");
+
+	if (!device)
+		return_VALUE(-EINVAL);
+
+	/*
+	 * Evaluate _STA if present.
+	 */
+	if (device->flags.dynamic_status) {
+		status = acpi_evaluate_integer(device->handle, "_STA", NULL, &sta);
+		if (ACPI_FAILURE(status))
+			return_VALUE(-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) = 0x0F;
+
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n", 
+		device->pnp.bus_id, (u32) STRUCT_TO_INT(device->status)));
+
+	return_VALUE(0);
+}
+
+
+/*
+static int
+acpi_bus_create_device_fs (struct device *device)
+{
+	ACPI_FUNCTION_TRACE("acpi_bus_create_device_fs");
+
+	if (!device)
+		return_VALUE(-EINVAL);
+
+	if (device->dir.entry)
+		return_VALUE(-EEXIST);
+
+	if (!device->parent)
+		device->dir.entry = proc_mkdir(device->pnp.bus_id, NULL);
+	else
+		device->dir.entry = proc_mkdir(device->pnp.bus_id,
+			device->parent->fs.entry);
+
+	if (!device->dir.entry) {
+		printk(KERN_ERR PREFIX "Unable to create fs entry '%s'\n",
+			device->pnp.bus_id);
+		return_VALUE(-ENODEV);
+	}
+
+	return_VALUE(0);
+}
+
+
+static int
+acpi_bus_remove_device_fs (struct device *device)
+{
+	ACPI_FUNCTION_TRACE("acpi_bus_create_device_fs");
+
+	if (!device)
+		return_VALUE(-EINVAL);
+
+	if (!device->dir.entry)
+		return_VALUE(-ENODEV);
+
+	if (!device->parent)
+		remove_proc_entry(device->pnp_bus_id, NULL);
+	else
+		remove_proc_entry(device->pnp.bus_id, device->parent->fs.entry);
+
+	device->dir.entry = NULL;
+
+	return_VALUE(0);
+}
+*/
+
+
+/* --------------------------------------------------------------------------
+                                 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;
+
+	ACPI_FUNCTION_TRACE("acpi_bus_get_power");
+
+	result = acpi_bus_get_device(handle, &device);
+	if (result)
+		return_VALUE(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_VALUE(-ENODEV);
+			device->power.state = (int) psc;
+		}
+		else if (device->power.flags.power_resources) {
+			result = acpi_power_get_inferred_state(device);
+			if (result)
+				return_VALUE(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_VALUE(0);
+}
+
+
+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'};
+
+	ACPI_FUNCTION_TRACE("acpi_bus_set_power");
+
+	result = acpi_bus_get_device(handle, &device);
+	if (result)
+		return_VALUE(result);
+
+	if ((state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
+		return_VALUE(-EINVAL);
+
+	/* Make sure this is a valid target state */
+
+	if (!device->flags.power_manageable) {
+		ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Device is not power manageable\n"));
+		return_VALUE(-ENODEV);
+	}
+	if (state == device->power.state) {
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at D%d\n", state));
+		return_VALUE(0);
+	}
+	if (!device->power.states[state].flags.valid) {
+		ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Device does not support D%d\n", state));
+		return_VALUE(-ENODEV);
+	}
+	if (device->parent && (state < device->parent->power.state)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Cannot set device to a higher-powered state than parent\n"));
+		return_VALUE(-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)
+		ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Error transitioning device [%s] to D%d\n",
+			device->pnp.bus_id, state));
+	else
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] transitioned to D%d\n",
+			device->pnp.bus_id, state));
+
+	return_VALUE(result);
+}
+
+
+static int
+acpi_bus_get_power_flags (
+	struct acpi_device	*device)
+{
+	acpi_status             status = 0;
+	acpi_handle		handle = 0;
+	u32                     i = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_bus_get_power_flags");
+
+	if (!device)
+		return -ENODEV;
+
+	/*
+	 * Power Management Flags
+	 */
+	status = acpi_get_handle(device->handle, "_PSC", &handle);
+	if (ACPI_SUCCESS(status))
+		device->power.flags.explicit_get = 1;
+	status = acpi_get_handle(device->handle, "_IRC", &handle);
+	if (ACPI_SUCCESS(status))
+		device->power.flags.inrush_current = 1;
+	status = acpi_get_handle(device->handle, "_PRW", &handle);
+	if (ACPI_SUCCESS(status))
+		device->power.flags.wake_capable = 1;
+
+	/*
+	 * Enumerate supported power management states
+	 */
+	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3; i++) {
+		struct acpi_device_power_state *ps = &device->power.states[i];
+		char		object_name[5] = {'_','P','R','0'+i,'\0'};
+
+		/* Evaluate "_PRx" to se if power resources are referenced */
+		acpi_evaluate_reference(device->handle, object_name, NULL,
+			&ps->resources);
+		if (ps->resources.count) {
+			device->power.flags.power_resources = 1;
+			ps->flags.valid = 1;
+		}
+
+		/* Evaluate "_PSx" to see if we can do explicit sets */
+		object_name[2] = 'S';
+		status = acpi_get_handle(device->handle, object_name, &handle);
+		if (ACPI_SUCCESS(status)) {
+			ps->flags.explicit_set = 1;
+			ps->flags.valid = 1;
+		}
+
+		/* State is valid if we have some power control */
+		if (ps->resources.count || ps->flags.explicit_set)
+			ps->flags.valid = 1;
+
+		ps->power = -1;		/* Unknown - driver assigned */
+		ps->latency = -1;	/* Unknown - driver assigned */
+	}
+
+	/* Set defaults for D0 and D3 states (always valid) */
+	device->power.states[ACPI_STATE_D0].flags.valid = 1;
+	device->power.states[ACPI_STATE_D0].power = 100;
+	device->power.states[ACPI_STATE_D3].flags.valid = 1;
+	device->power.states[ACPI_STATE_D3].power = 0;
+
+	/*
+	 * System Power States
+	 * -------------------
+	 */
+	/* TBD: S1-S4 power state support and resource requirements. */
+	/*
+	for (i=ACPI_STATE_S1; i<ACPI_STATE_S5; i++) {
+		char name[5] = {'_','S',('0'+i),'D','\0'};
+		status = acpi_evaluate_integer(device->handle, name, NULL,
+			&state);
+		if (ACPI_FAILURE(status))
+			continue;
+	}
+	*/
+
+	/* TBD: System wake support and resource requirements. */
+
+	device->power.state = ACPI_STATE_UNKNOWN;
+
+	return 0;
+}
+
+
+/* --------------------------------------------------------------------------
+                              Performance Management
+   -------------------------------------------------------------------------- */
+
+static int
+acpi_bus_get_perf_flags (
+	struct acpi_device	*device)
+{
+	ACPI_FUNCTION_TRACE("acpi_bus_get_perf_flags");
+
+	if (!device)
+		return -ENODEV;
+
+	device->performance.state = ACPI_STATE_UNKNOWN;
+
+	return 0;
+}
+
+
+/* --------------------------------------------------------------------------
+                                Event Management
+   -------------------------------------------------------------------------- */
+
+static spinlock_t		acpi_bus_event_lock = SPIN_LOCK_UNLOCKED;
+
+LIST_HEAD(acpi_bus_event_list);
+DECLARE_WAIT_QUEUE_HEAD(acpi_bus_event_queue);
+
+extern int			event_is_open;
+
+int
+acpi_bus_generate_event (
+	struct acpi_device	*device,
+	u8			type,
+	int			data)
+{
+	struct acpi_bus_event	*event = NULL;
+	u32			flags = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_bus_generate_event");
+
+	if (!device)
+		return_VALUE(-EINVAL);
+
+	/* drop event on the floor if no one's listening */
+	if (!event_is_open)
+		return_VALUE(0);
+
+	event = kmalloc(sizeof(struct acpi_bus_event), GFP_ATOMIC);
+	if (!event)
+		return_VALUE(-ENOMEM);
+
+	sprintf(event->device_class, "%s", device->pnp.device_class);
+	sprintf(event->bus_id, "%s", device->pnp.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_VALUE(0);
+}
+
+int
+acpi_bus_receive_event (
+	struct acpi_bus_event	*event)
+{
+	u32			flags = 0;
+	struct acpi_bus_event	*entry = NULL;
+
+	DECLARE_WAITQUEUE(wait, current);
+
+	ACPI_FUNCTION_TRACE("acpi_bus_receive_event");
+
+	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_VALUE(-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_VALUE(-ENODEV);
+
+	memcpy(event, entry, sizeof(struct acpi_bus_event));
+
+	kfree(entry);
+
+	return_VALUE(0);
+}
+
+
+/* --------------------------------------------------------------------------
+                               Namespace Management
+   -------------------------------------------------------------------------- */
+
+#define WALK_UP			0
+#define WALK_DOWN		1
+
+typedef int (*acpi_bus_walk_callback)(struct acpi_device*, int, void*);
+
+#define HAS_CHILDREN(d)		((d)->children.next != &((d)->children))
+#define HAS_SIBLINGS(d)		(((d)->parent) && ((d)->node.next != &(d)->parent->children))
+#define NODE_TO_DEVICE(n)	(list_entry(n, struct acpi_device, node))
+
+
+/**
+ * acpi_bus_walk
+ * -------------
+ * Used to walk the ACPI Bus's device namespace.  Can walk down (depth-first)
+ * or up.  Able to parse starting at any node in the namespace.  Note that a
+ * callback return value of -ELOOP will terminate the walk.
+ *
+ * @start:	starting point
+ * callback:	function to call for every device encountered while parsing
+ * direction:	direction to parse (up or down)
+ * @data:	context for this search operation
+ */
+static int
+acpi_bus_walk (
+	struct acpi_device	*start, 
+	acpi_bus_walk_callback	callback, 
+	int			direction, 
+	void			*data)
+{
+	int			result = 0;
+	int			level = 0;
+	struct acpi_device	*device = NULL;
+
+	if (!start || !callback)
+		return -EINVAL;
+
+	device = start;
+
+	/*
+	 * Parse Namespace
+	 * ---------------
+	 * Parse a given subtree (specified by start) in the given direction.
+	 * Walking 'up' simply means that we execute the callback on leaf
+	 * devices prior to their parents (useful for things like removing
+	 * or powering down a subtree).
+	 */
+
+	while (device) {
+
+		if (direction == WALK_DOWN)
+			if (-ELOOP == callback(device, level, data))
+				break;
+
+		/* Depth First */
+
+		if (HAS_CHILDREN(device)) {
+			device = NODE_TO_DEVICE(device->children.next);
+			++level;
+			continue;
+		}
+
+		if (direction == WALK_UP)
+			if (-ELOOP == callback(device, level, data))
+				break;
+
+		/* Now Breadth */
+
+		if (HAS_SIBLINGS(device)) {
+			device = NODE_TO_DEVICE(device->node.next);
+			continue;
+		}
+
+		/* Scope Exhausted - Find Next */
+
+		while ((device = device->parent)) {
+			--level;
+			if (HAS_SIBLINGS(device)) {
+				device = NODE_TO_DEVICE(device->node.next);
+				break;
+			}
+		}
+	}
+
+	if ((direction == WALK_UP) && (result == 0))
+		callback(start, level, data);
+
+	return result;
+}
+
+
+/* --------------------------------------------------------------------------
+                             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;
+
+	ACPI_FUNCTION_TRACE("acpi_bus_check_device");
+
+	if (!device)
+		return_VALUE(-EINVAL);
+
+	if (status_changed)
+		*status_changed = 0;
+
+	old_status = device->status;
+
+	/*
+	 * Make sure this device's parent is present before we go about
+	 * messing with the device.
+	 */
+	if (device->parent && !device->parent->status.present) {
+		device->status = device->parent->status;
+		if (STRUCT_TO_INT(old_status) != STRUCT_TO_INT(device->status)) {
+			if (status_changed)
+				*status_changed = 1;
+		}
+		return_VALUE(0);
+	}
+
+	status = acpi_bus_get_status(device);
+	if (ACPI_FAILURE(status))
+		return_VALUE(-ENODEV);
+
+	if (STRUCT_TO_INT(old_status) == STRUCT_TO_INT(device->status))
+		return_VALUE(0);
+
+	if (status_changed)
+		*status_changed = 1;
+	
+	/*
+	 * Device Insertion/Removal
+	 */
+	if ((device->status.present) && !(old_status.present)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device insertion detected\n"));
+		/* TBD: Handle device insertion */
+	}
+	else if (!(device->status.present) && (old_status.present)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device removal detected\n"));
+		/* TBD: Handle device removal */
+	}
+
+	return_VALUE(0);
+}
+
+
+static int
+acpi_bus_check_scope (
+	struct acpi_device	*device)
+{
+	int			result = 0;
+	int			status_changed = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_bus_check_scope");
+
+	if (!device)
+		return_VALUE(-EINVAL);
+
+	/* Status Change? */
+	result = acpi_bus_check_device(device, &status_changed);
+	if (result)
+		return_VALUE(result);
+
+	if (!status_changed)
+		return_VALUE(0);
+
+	/*
+	 * TBD: Enumerate child devices within this device's scope and
+	 *       run acpi_bus_check_device()'s on them.
+	 */
+
+	return_VALUE(0);
+}
+
+
+/**
+ * acpi_bus_notify
+ * ---------------
+ * Callback for all 'system-level' device notifications (values 0x00-0x7F).
+ */
+static void 
+acpi_bus_notify (
+	acpi_handle             handle,
+	u32                     type,
+	void                    *data)
+{
+	int			result = 0;
+	struct acpi_device	*device = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_bus_notify");
+
+	if (acpi_bus_get_device(handle, &device))
+		return_VOID;
+
+	switch (type) {
+
+	case ACPI_NOTIFY_BUS_CHECK:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Received BUS CHECK notification for device [%s]\n", 
+			device->pnp.bus_id));
+		result = acpi_bus_check_scope(device);
+		/* 
+		 * TBD: We'll need to outsource certain events to non-ACPI
+		 *	drivers via the device manager (device.c).
+		 */
+		break;
+
+	case ACPI_NOTIFY_DEVICE_CHECK:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Received DEVICE CHECK notification for device [%s]\n", 
+			device->pnp.bus_id));
+		result = acpi_bus_check_device(device, NULL);
+		/* 
+		 * TBD: We'll need to outsource certain events to non-ACPI
+		 *	drivers via the device manager (device.c).
+		 */
+		break;
+
+	case ACPI_NOTIFY_DEVICE_WAKE:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Received DEVICE WAKE notification for device [%s]\n", 
+			device->pnp.bus_id));
+		/* TBD */
+		break;
+
+	case ACPI_NOTIFY_EJECT_REQUEST:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Received EJECT REQUEST notification for device [%s]\n", 
+			device->pnp.bus_id));
+		/* TBD */
+		break;
+
+	case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Received DEVICE CHECK LIGHT notification for device [%s]\n", 
+			device->pnp.bus_id));
+		/* TBD: Exactly what does 'light' mean? */
+		break;
+
+	case ACPI_NOTIFY_FREQUENCY_MISMATCH:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Received FREQUENCY MISMATCH notification for device [%s]\n", 
+			device->pnp.bus_id));
+		/* TBD */
+		break;
+
+	case ACPI_NOTIFY_BUS_MODE_MISMATCH:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Received BUS MODE MISMATCH notification for device [%s]\n", 
+			device->pnp.bus_id));
+		/* TBD */
+		break;
+
+	case ACPI_NOTIFY_POWER_FAULT:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Received POWER FAULT notification for device [%s]\n", 
+			device->pnp.bus_id));
+		/* TBD */
+		break;
+
+	default:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Received unknown/unsupported notification [%08x]\n", 
+			type));
+		break;
+	}
+
+	return_VOID;
+}
+
+
+/* --------------------------------------------------------------------------
+                                 Driver Management
+   -------------------------------------------------------------------------- */
+
+static LIST_HEAD(acpi_bus_drivers);
+static DECLARE_MUTEX(acpi_bus_drivers_lock);
+
+
+/**
+ * acpi_bus_match 
+ * --------------
+ * Checks the device's hardware (_HID) or compatible (_CID) ids to see if it
+ * matches the specified driver's criteria.
+ */
+static int
+acpi_bus_match (
+	struct acpi_device	*device,
+	struct acpi_driver	*driver)
+{
+	int error = 0;
+
+	if (device->flags.hardware_id)
+		if (strstr(driver->ids, device->pnp.hardware_id))
+			goto Done;
+
+	if (device->flags.compatible_ids) {
+		struct acpi_compatible_id_list *cid_list = device->pnp.cid_list;
+		int i;
+
+		/* compare multiple _CID entries against driver ids */
+		for (i = 0; i < cid_list->count; i++)
+		{
+			if (strstr(driver->ids, cid_list->id[i].value))
+				goto Done;
+		}
+	}
+	error = -ENOENT;
+
+ Done:
+	
+	return error;
+}
+
+
+/**
+ * acpi_bus_driver_init 
+ * --------------------
+ * Used to initialize a device via its device driver.  Called whenever a 
+ * driver is bound to a device.  Invokes the driver's add() and start() ops.
+ */
+static int
+acpi_bus_driver_init (
+	struct acpi_device	*device, 
+	struct acpi_driver	*driver)
+{
+	int			result = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_bus_driver_init");
+
+	if (!device || !driver)
+		return_VALUE(-EINVAL);
+
+	if (!driver->ops.add)
+		return_VALUE(-ENOSYS);
+
+	result = driver->ops.add(device);
+	if (result) {
+		device->driver = NULL;
+		acpi_driver_data(device) = NULL;
+		return_VALUE(result);
+	}
+
+	device->driver = driver;
+
+	/*
+	 * TBD - Configuration Management: Assign resources to device based
+	 * upon possible configuration and currently allocated resources.
+	 */
+
+	if (driver->ops.start) {
+		result = driver->ops.start(device);
+		if (result && driver->ops.remove)
+			driver->ops.remove(device, ACPI_BUS_REMOVAL_NORMAL);
+		return_VALUE(result);
+	}
+
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Driver successfully bound to device\n"));
+
+#ifdef CONFIG_LDM
+	/* 
+	 * Update the device information (in the global device hierarchy) now
+	 * that there's a driver bound to it.
+	 */
+	strncpy(device->dev.name, device->pnp.device_name, 
+		sizeof(device->dev.name));
+#endif
+
+	if (driver->ops.scan) {
+		driver->ops.scan(device);
+	}
+
+	return_VALUE(0);
+}
+
+
+/**
+ * acpi_bus_attach 
+ * -------------
+ * Callback for acpi_bus_walk() used to find devices that match a specific 
+ * driver's criteria and then attach the driver.
+ */
+static int
+acpi_bus_attach (
+	struct acpi_device	*device, 
+	int			level, 
+	void			*data)
+{
+	int			result = 0;
+	struct acpi_driver	*driver = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_bus_attach");
+
+	if (!device || !data)
+		return_VALUE(-EINVAL);
+
+	driver = (struct acpi_driver *) data;
+
+	if (device->driver)
+		return_VALUE(-EEXIST);
+
+	if (!device->status.present)
+		return_VALUE(-ENODEV);
+
+	result = acpi_bus_match(device, driver);
+	if (result)
+		return_VALUE(result);
+
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n",
+		driver->name, device->pnp.bus_id));
+	
+	result = acpi_bus_driver_init(device, driver);
+	if (result)
+		return_VALUE(result);
+
+	down(&acpi_bus_drivers_lock);
+	++driver->references;
+	up(&acpi_bus_drivers_lock);
+
+	return_VALUE(0);
+}
+
+
+/**
+ * acpi_bus_unattach 
+ * -----------------
+ * Callback for acpi_bus_walk() used to find devices that match a specific 
+ * driver's criteria and unattach the driver.
+ */
+static int
+acpi_bus_unattach (
+	struct acpi_device	*device, 
+	int			level, 
+	void			*data)
+{
+	int			result = 0;
+	struct acpi_driver	*driver = (struct acpi_driver *) data;
+
+	ACPI_FUNCTION_TRACE("acpi_bus_unattach");
+
+	if (!device || !driver)
+		return_VALUE(-EINVAL);
+
+	if (device->driver != driver)
+		return_VALUE(-ENOENT);
+
+	if (!driver->ops.remove)
+		return_VALUE(-ENOSYS);
+
+	result = driver->ops.remove(device, ACPI_BUS_REMOVAL_NORMAL);
+	if (result)
+		return_VALUE(result);
+
+	device->driver = NULL;
+	acpi_driver_data(device) = NULL;
+
+	down(&acpi_bus_drivers_lock);
+	driver->references--;
+	up(&acpi_bus_drivers_lock);
+
+	return_VALUE(0);
+}
+
+
+/**
+ * acpi_bus_find_driver 
+ * --------------------
+ * Parses the list of registered drivers looking for a driver applicable for
+ * the specified device.
+ */
+static int
+acpi_bus_find_driver (
+	struct acpi_device	*device)
+{
+	int			result = -ENODEV;
+	struct list_head	*entry = NULL;
+	struct acpi_driver	*driver = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_bus_find_driver");
+
+	if (!device || device->driver)
+		return_VALUE(-EINVAL);
+
+	down(&acpi_bus_drivers_lock);
+
+	list_for_each(entry, &acpi_bus_drivers) {
+
+		driver = list_entry(entry, struct acpi_driver, node);
+
+		if (acpi_bus_match(device, driver))
+			continue;
+
+		result = acpi_bus_driver_init(device, driver);
+		if (!result)
+			++driver->references;
+
+		break;
+	}
+
+	up(&acpi_bus_drivers_lock);
+
+	return_VALUE(result);
+}
+
+
+/**
+ * acpi_bus_register_driver 
+ * ------------------------ 
+ * Registers a driver with the ACPI bus.  Searches the namespace for all
+ * devices that match the driver's criteria and binds.
+ */
+int
+acpi_bus_register_driver (
+	struct acpi_driver	*driver)
+{
+	ACPI_FUNCTION_TRACE("acpi_bus_register_driver");
+
+	if (!driver)
+		return_VALUE(-EINVAL);
+
+	if (acpi_disabled)
+		return_VALUE(-ENODEV);
+
+	down(&acpi_bus_drivers_lock);
+	list_add_tail(&driver->node, &acpi_bus_drivers);
+	up(&acpi_bus_drivers_lock);
+
+	acpi_bus_walk(acpi_root, acpi_bus_attach, 
+		WALK_DOWN, driver);
+
+	return_VALUE(driver->references);
+}
+
+
+/**
+ * acpi_bus_unregister_driver 
+ * --------------------------
+ * Unregisters a driver with the ACPI bus.  Searches the namespace for all
+ * devices that match the driver's criteria and unbinds.
+ */
+int
+acpi_bus_unregister_driver (
+	struct acpi_driver	*driver)
+{
+	ACPI_FUNCTION_TRACE("acpi_bus_unregister_driver");
+
+	if (!driver)
+		return_VALUE(-EINVAL);
+
+	acpi_bus_walk(acpi_root, acpi_bus_unattach, WALK_UP, driver);
+
+	if (driver->references)
+		return_VALUE(driver->references);
+
+	down(&acpi_bus_drivers_lock);
+	list_del(&driver->node);
+	up(&acpi_bus_drivers_lock);
+
+	return_VALUE(0);
+}
+
+
+/* --------------------------------------------------------------------------
+                                 Device Enumeration
+   -------------------------------------------------------------------------- */
+
+static int 
+acpi_bus_get_flags (
+	struct acpi_device	*device)
+{
+	acpi_status		status = AE_OK;
+	acpi_handle		temp = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_bus_get_flags");
+
+	/* Presence of _STA indicates 'dynamic_status' */
+	status = acpi_get_handle(device->handle, "_STA", &temp);
+	if (ACPI_SUCCESS(status))
+		device->flags.dynamic_status = 1;
+
+	/* Presence of _CID indicates 'compatible_ids' */
+	status = acpi_get_handle(device->handle, "_CID", &temp);
+	if (ACPI_SUCCESS(status))
+		device->flags.compatible_ids = 1;
+
+	/* Presence of _RMV indicates 'removable' */
+	status = acpi_get_handle(device->handle, "_RMV", &temp);
+	if (ACPI_SUCCESS(status))
+		device->flags.removable = 1;
+
+	/* Presence of _EJD|_EJ0 indicates 'ejectable' */
+	status = acpi_get_handle(device->handle, "_EJD", &temp);
+	if (ACPI_SUCCESS(status))
+		device->flags.ejectable = 1;
+	else {
+		status = acpi_get_handle(device->handle, "_EJ0", &temp);
+		if (ACPI_SUCCESS(status))
+			device->flags.ejectable = 1;
+	}
+
+	/* Presence of _LCK indicates 'lockable' */
+	status = acpi_get_handle(device->handle, "_LCK", &temp);
+	if (ACPI_SUCCESS(status))
+		device->flags.lockable = 1;
+
+	/* Presence of _PS0|_PR0 indicates 'power manageable' */
+	status = acpi_get_handle(device->handle, "_PS0", &temp);
+	if (ACPI_FAILURE(status))
+		status = acpi_get_handle(device->handle, "_PR0", &temp);
+	if (ACPI_SUCCESS(status))
+		device->flags.power_manageable = 1;
+
+	/* TBD: Peformance management */
+
+	return_VALUE(0);
+}
+
+
+static int 
+acpi_bus_add (
+	struct acpi_device	**child,
+	struct acpi_device	*parent,
+	acpi_handle		handle,
+	int			type)
+{
+	int			result = 0;
+	acpi_status		status = AE_OK;
+	struct acpi_device	*device = NULL;
+	char			bus_id[5] = {'?',0};
+	struct acpi_buffer	buffer = {0, NULL};
+	struct acpi_device_info	*info;
+	char			*hid = NULL;
+	char			*uid = NULL;
+	struct acpi_compatible_id_list *cid_list = NULL;
+	int			i = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_bus_add");
+
+	if (!child)
+		return_VALUE(-EINVAL);
+
+	device = kmalloc(sizeof(struct acpi_device), GFP_KERNEL);
+	if (!device) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Memory allocation error\n"));
+		return_VALUE(-ENOMEM);
+	}
+	memset(device, 0, sizeof(struct acpi_device));
+
+	device->handle = handle;
+	device->parent = parent;
+
+	/*
+	 * Bus ID
+	 * ------
+	 * The device's Bus ID is simply the object name.
+	 * TBD: Shouldn't this value be unique (within the ACPI namespace)?
+	 */
+	switch (type) {
+	case ACPI_BUS_TYPE_SYSTEM:
+		sprintf(device->pnp.bus_id, "%s", "ACPI");
+		break;
+	case ACPI_BUS_TYPE_POWER_BUTTON:
+		sprintf(device->pnp.bus_id, "%s", "PWRF");
+		break;
+	case ACPI_BUS_TYPE_SLEEP_BUTTON:
+		sprintf(device->pnp.bus_id, "%s", "SLPF");
+		break;
+	default:
+		buffer.length = sizeof(bus_id);
+		buffer.pointer = bus_id;
+		acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
+		/* Clean up trailing underscores (if any) */
+		for (i = 3; i > 1; i--) {
+			if (bus_id[i] == '_')
+				bus_id[i] = '\0';
+			else
+				break;
+		}
+		sprintf(device->pnp.bus_id, "%s", bus_id);
+		buffer.pointer = NULL;
+		break;
+	}
+
+	/*
+	 * Flags
+	 * -----
+	 * Get prior to calling acpi_bus_get_status() so we know whether
+	 * or not _STA is present.  Note that we only look for object
+	 * handles -- cannot evaluate objects until we know the device is
+	 * present and properly initialized.
+	 */
+	result = acpi_bus_get_flags(device);
+	if (result)
+		goto end;
+
+	/*
+	 * Status
+	 * ------
+	 * See if the device is present.  We always assume that non-Device()
+	 * objects (e.g. thermal zones, power resources, processors, etc.) are
+	 * present, functioning, etc. (at least when parent object is present).
+	 * Note that _STA has a different meaning for some objects (e.g.
+	 * power resources) so we need to be careful how we use it.
+	 */
+	switch (type) {
+	case ACPI_BUS_TYPE_DEVICE:
+		result = acpi_bus_get_status(device);
+		if (result)
+			goto end;
+		break;
+	default:
+		STRUCT_TO_INT(device->status) = 0x0F;
+		break;
+	}
+	if (!device->status.present) {
+		result = -ENOENT;
+		goto end;
+	}
+
+	/*
+	 * Initialize Device
+	 * -----------------
+	 * TBD: Synch with Core's enumeration/initialization process.
+	 */
+
+	/*
+	 * Hardware ID, Unique ID, & Bus Address
+	 * -------------------------------------
+	 */
+	switch (type) {
+	case ACPI_BUS_TYPE_DEVICE:
+		buffer.length = ACPI_ALLOCATE_BUFFER;
+		buffer.pointer = NULL;
+		status = acpi_get_object_info(handle, &buffer);
+		if (ACPI_FAILURE(status)) {
+			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+				"Error reading device info\n"));
+			result = -ENODEV;
+			goto end;
+		}
+		info = buffer.pointer;
+		if (info->valid & ACPI_VALID_HID)
+			hid = info->hardware_id.value;
+		if (info->valid & ACPI_VALID_UID)
+			uid = info->unique_id.value;
+		if (info->valid & ACPI_VALID_CID) {
+			cid_list = &info->compatibility_id;
+			device->pnp.cid_list = kmalloc(cid_list->size, GFP_KERNEL);
+			if (device->pnp.cid_list)
+				memcpy(device->pnp.cid_list, cid_list, cid_list->size);
+			else
+				ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Memory allocation error\n"));
+		}
+		if (info->valid & ACPI_VALID_ADR) {
+			device->pnp.bus_address = info->address;
+			device->flags.bus_address = 1;
+		}
+		break;
+	case ACPI_BUS_TYPE_POWER:
+		hid = ACPI_POWER_HID;
+		break;
+	case ACPI_BUS_TYPE_PROCESSOR:
+		hid = ACPI_PROCESSOR_HID;
+		break;
+	case ACPI_BUS_TYPE_SYSTEM:
+		hid = ACPI_SYSTEM_HID;
+		break;
+	case ACPI_BUS_TYPE_THERMAL:
+		hid = ACPI_THERMAL_HID;
+		break;
+	case ACPI_BUS_TYPE_POWER_BUTTON:
+		hid = ACPI_BUTTON_HID_POWERF;
+		break;
+	case ACPI_BUS_TYPE_SLEEP_BUTTON:
+		hid = ACPI_BUTTON_HID_SLEEPF;
+		break;
+	}
+
+	/* 
+	 * \_SB
+	 * ----
+	 * Fix for the system root bus device -- the only root-level device.
+	 */
+	if ((parent == ACPI_ROOT_OBJECT) && (type == ACPI_BUS_TYPE_DEVICE)) {
+		hid = ACPI_BUS_HID;
+		sprintf(device->pnp.device_name, "%s", ACPI_BUS_DEVICE_NAME);
+		sprintf(device->pnp.device_class, "%s", ACPI_BUS_CLASS);
+	}
+
+	if (hid) {
+		sprintf(device->pnp.hardware_id, "%s", hid);
+		device->flags.hardware_id = 1;
+	}
+	if (uid) {
+		sprintf(device->pnp.unique_id, "%s", uid);
+		device->flags.unique_id = 1;
+	}
+
+	/*
+	 * If we called get_object_info, we now are finished with the buffer,
+	 * so we can free it.
+	 */
+	if (buffer.pointer)
+		acpi_os_free(buffer.pointer);
+
+	/*
+	 * Power Management
+	 * ----------------
+	 */
+	if (device->flags.power_manageable) {
+		result = acpi_bus_get_power_flags(device);
+		if (result)
+			goto end;
+	}
+
+	/*
+	 * Performance Management
+	 * ----------------------
+	 */
+	if (device->flags.performance_manageable) {
+		result = acpi_bus_get_perf_flags(device);
+		if (result)
+			goto end;
+	}
+
+	/*
+	 * Context
+	 * -------
+	 * Attach this 'struct acpi_device' to the ACPI object.  This makes
+	 * resolutions from handle->device very efficient.  Note that we need
+	 * to be careful with fixed-feature devices as they all attach to the
+	 * root object.
+	 */
+	switch (type) {
+	case ACPI_BUS_TYPE_POWER_BUTTON:
+	case ACPI_BUS_TYPE_SLEEP_BUTTON:
+		break;
+	default:
+		status = acpi_attach_data(device->handle,
+			acpi_bus_data_handler, device);
+		break;
+	}
+	if (ACPI_FAILURE(status)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+			"Error attaching device data\n"));
+		result = -ENODEV;
+		goto end;
+	}
+
+	/*
+	 * Linkage
+	 * -------
+	 * Link this device to its parent and siblings.
+	 */
+	INIT_LIST_HEAD(&device->children);
+	if (!device->parent)
+		INIT_LIST_HEAD(&device->node);
+	else
+		list_add_tail(&device->node, &device->parent->children);
+
+#ifdef CONFIG_ACPI_DEBUG
+	{
+		char			*type_string = NULL;
+		char			name[80] = {'?','\0'};
+		struct acpi_buffer	buffer = {sizeof(name), name};
+
+		acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
+
+		switch (type) {
+		case ACPI_BUS_TYPE_DEVICE:
+			type_string = "Device";
+			break;
+		case ACPI_BUS_TYPE_POWER:
+			type_string = "Power Resource";
+			break;
+		case ACPI_BUS_TYPE_PROCESSOR:
+			type_string = "Processor";
+			break;
+		case ACPI_BUS_TYPE_SYSTEM:
+			type_string = "System";
+			break;
+		case ACPI_BUS_TYPE_THERMAL:
+			type_string = "Thermal Zone";
+			break;
+		case ACPI_BUS_TYPE_POWER_BUTTON:
+			type_string = "Power Button";
+			sprintf(name, "PWRB");
+			break;
+		case ACPI_BUS_TYPE_SLEEP_BUTTON:
+			type_string = "Sleep Button";
+			sprintf(name, "SLPB");
+			break;
+		}
+
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %s %s [%p]\n", 
+			type_string, name, handle));
+	}
+#endif /*CONFIG_ACPI_DEBUG*/
+
+	/*
+	 * Global Device Hierarchy:
+	 * ------------------------
+	 * Register this device with the global device hierarchy.
+	 */
+	acpi_device_register(device, parent);
+
+	/*
+	 * Bind _ADR-Based Devices
+	 * -----------------------
+	 * If there's a a bus address (_ADR) then we utilize the parent's 
+	 * 'bind' function (if exists) to bind the ACPI- and natively-
+	 * enumerated device representations.
+	 */
+	if (device->flags.bus_address) {
+		if (device->parent && device->parent->ops.bind)
+			device->parent->ops.bind(device);
+	}
+
+	/*
+	 * Locate & Attach Driver
+	 * ----------------------
+	 * If there's a hardware id (_HID) or compatible ids (_CID) we check
+	 * to see if there's a driver installed for this kind of device.  Note
+	 * that drivers can install before or after a device is enumerated.
+	 *
+	 * TBD: Assumes LDM provides driver hot-plug capability.
+	 */
+	if (device->flags.hardware_id || device->flags.compatible_ids)
+		acpi_bus_find_driver(device);
+
+end:
+	if (result) {
+		if (device->pnp.cid_list) {
+			kfree(device->pnp.cid_list);
+		}
+		kfree(device);
+		return_VALUE(result);
+	}
+	*child = device;
+
+	return_VALUE(0);
+}
+
+
+static int
+acpi_bus_remove (
+	struct acpi_device	*device, 
+	int			type)
+{
+	ACPI_FUNCTION_TRACE("acpi_bus_remove");
+
+	if (!device)
+		return_VALUE(-ENODEV);
+
+	acpi_device_unregister(device);
+
+#if 0
+	if (device->pnp.cid_list)
+		kfree(device->pnp.cid_list);
+#endif
+	kfree(device);
+
+	return_VALUE(0);
+}
+
+
+int
+acpi_bus_scan (
+	struct acpi_device	*start)
+{
+	acpi_status		status = AE_OK;
+	struct acpi_device	*parent = NULL;
+	struct acpi_device	*child = NULL;
+	acpi_handle		phandle = 0;
+	acpi_handle		chandle = 0;
+	acpi_object_type	type = 0;
+	u32			level = 1;
+
+	ACPI_FUNCTION_TRACE("acpi_bus_scan");
+
+	if (!start)
+		return_VALUE(-EINVAL);
+
+	parent = start;
+	phandle = start->handle;
+	
+	/*
+	 * Parse through the ACPI namespace, identify all 'devices', and
+	 * create a new 'struct acpi_device' for each.
+	 */
+	while ((level > 0) && parent) {
+
+		status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
+			chandle, &chandle);
+
+		/*
+		 * If this scope is exhausted then move our way back up.
+		 */
+		if (ACPI_FAILURE(status)) {
+			level--;
+			chandle = phandle;
+			acpi_get_parent(phandle, &phandle);
+			if (parent->parent)
+				parent = parent->parent;
+			continue;
+		}
+
+		status = acpi_get_type(chandle, &type);
+		if (ACPI_FAILURE(status))
+			continue;
+
+		/*
+		 * If this is a scope object then parse it (depth-first).
+		 */
+		if (type == ACPI_TYPE_LOCAL_SCOPE) {
+			level++;
+			phandle = chandle;
+			chandle = 0;
+			continue;
+		}
+
+		/*
+		 * We're only interested in objects that we consider 'devices'.
+		 */
+		switch (type) {
+		case ACPI_TYPE_DEVICE:
+			type = ACPI_BUS_TYPE_DEVICE;
+			break;
+		case ACPI_TYPE_PROCESSOR:
+			type = ACPI_BUS_TYPE_PROCESSOR;
+			break;
+		case ACPI_TYPE_THERMAL:
+			type = ACPI_BUS_TYPE_THERMAL;
+			break;
+		case ACPI_TYPE_POWER:
+			type = ACPI_BUS_TYPE_POWER;
+			break;
+		default:
+			continue;
+		}
+
+		status = acpi_bus_add(&child, parent, chandle, type);
+		if (ACPI_FAILURE(status))
+			continue;
+
+		/*
+		 * If the device is present, enabled, and functioning then
+		 * parse its scope (depth-first).  Note that we need to
+		 * represent absent devices to facilitate PnP notifications
+		 * -- but only the subtree head (not all of its children,
+		 * which will be enumerated when the parent is inserted).
+		 *
+		 * TBD: Need notifications and other detection mechanisms
+		 *	in place before we can fully implement this.
+		 */
+		if (child->status.present) {
+			status = acpi_get_next_object(ACPI_TYPE_ANY, chandle,
+				0, NULL);
+			if (ACPI_SUCCESS(status)) {
+				level++;
+				phandle = chandle;
+				chandle = 0;
+				parent = child;
+			}
+		}
+	}
+
+	return_VALUE(0);
+}
+
+
+static int
+acpi_bus_scan_fixed (
+	struct acpi_device	*root)
+{
+	int			result = 0;
+	struct acpi_device	*device = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_bus_scan_fixed");
+
+	if (!root)
+		return_VALUE(-ENODEV);
+
+	/*
+	 * Enumerate all fixed-feature devices.
+	 */
+	if (acpi_fadt.pwr_button == 0)
+		result = acpi_bus_add(&device, acpi_root, 
+			NULL, ACPI_BUS_TYPE_POWER_BUTTON);
+
+	if (acpi_fadt.sleep_button == 0)
+		result = acpi_bus_add(&device, acpi_root, 
+			NULL, ACPI_BUS_TYPE_SLEEP_BUTTON);
+
+	return_VALUE(result);
+}
+
+
+/* --------------------------------------------------------------------------
+                             Initialization/Cleanup
+   -------------------------------------------------------------------------- */
+
+static int __init
+acpi_bus_init_irq (void)
+{
+	acpi_status		status = AE_OK;
+	union acpi_object	arg = {ACPI_TYPE_INTEGER};
+	struct acpi_object_list	arg_list = {1, &arg};
+	char			*message = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_bus_init_irq");
+
+	/* 
+	 * Let the system know what interrupt model we are using by
+	 * evaluating the \_PIC object, if exists.
+	 */
+
+	switch (acpi_irq_model) {
+	case ACPI_IRQ_MODEL_PIC:
+		message = "PIC";
+		break;
+	case ACPI_IRQ_MODEL_IOAPIC:
+		message = "IOAPIC";
+		break;
+	case ACPI_IRQ_MODEL_IOSAPIC:
+		message = "IOSAPIC";
+		break;
+	default:
+		printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
+		return_VALUE(-ENODEV);
+	}
+
+	printk(KERN_INFO PREFIX "Using %s for interrupt routing\n", message);
+
+	arg.integer.value = acpi_irq_model;
+
+	status = acpi_evaluate_object(NULL, "\\_PIC", &arg_list, NULL);
+	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PIC\n"));
+		return_VALUE(-ENODEV);
+	}
+
+	return_VALUE(0);
+}
+
+
+static int __init
+acpi_bus_init (void)
+{
+	int			result = 0;
+	acpi_status		status = AE_OK;
+	struct acpi_buffer	buffer = {sizeof(acpi_fadt), &acpi_fadt};
+
+	ACPI_FUNCTION_TRACE("acpi_bus_init");
+
+	status = acpi_initialize_subsystem();
+	if (ACPI_FAILURE(status)) {
+		printk(KERN_ERR PREFIX "Unable to initialize the ACPI Interpreter\n");
+		goto error0;
+	}
+
+	status = acpi_load_tables();
+	if (ACPI_FAILURE(status)) {
+		printk(KERN_ERR PREFIX "Unable to load the System Description Tables\n");
+		goto error0;
+	}
+
+	/*
+	 * Get a separate copy of the FADT for use by other drivers.
+	 */
+	status = acpi_get_table(ACPI_TABLE_FADT, 1, &buffer);
+	if (ACPI_FAILURE(status)) {
+		printk(KERN_ERR PREFIX "Unable to get the FADT\n");
+		goto error1;
+	}
+
+#ifdef CONFIG_X86
+        /* Ensure the SCI is set to level-triggered, active-low */
+        if (acpi_ioapic)
+         	mp_config_ioapic_for_sci(acpi_fadt.sci_int);
+	else
+                eisa_set_level_irq(acpi_fadt.sci_int);
+#endif
+
+	status = acpi_enable_subsystem(ACPI_FULL_INITIALIZATION);
+	if (ACPI_FAILURE(status)) {
+		printk(KERN_ERR PREFIX "Unable to start the ACPI Interpreter\n");
+		goto error1;
+	}
+
+#ifdef CONFIG_ACPI_EC
+	/*
+	 * ACPI 2.0 requires the EC driver to be loaded and work before
+	 * the EC device is found in the namespace. This is accomplished
+	 * by looking for the ECDT table, and getting the EC parameters out
+	 * of that.
+	 */
+	result = acpi_ec_ecdt_probe();
+	if (result) {
+		goto error1;
+	}
+#endif
+
+	status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
+	if (ACPI_FAILURE(status)) {
+		printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
+		goto error1;
+	}
+
+	printk(KERN_INFO PREFIX "Interpreter enabled\n");
+
+	/*
+	 * Get the system interrupt model and evaluate \_PIC.
+	 */
+	result = acpi_bus_init_irq();
+	if (result)
+		goto error1;
+
+	/*
+	 * Register the for all standard device notifications.
+	 */
+	status = acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY, &acpi_bus_notify, NULL);
+	if (ACPI_FAILURE(status)) {
+		printk(KERN_ERR PREFIX "Unable to register for device notifications\n");
+		result = -ENODEV;
+		goto error1;
+	}
+
+	/*
+	 * Create the root device in the bus's device tree
+	 */
+	result = acpi_bus_add(&acpi_root, NULL, ACPI_ROOT_OBJECT, 
+		ACPI_BUS_TYPE_SYSTEM);
+	if (result)
+		goto error2;
+
+	/*
+	 * Create the top ACPI proc directory
+	 */
+	acpi_device_dir(acpi_root) = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
+	if (!acpi_root) {
+		result = -ENODEV;
+		goto error3;
+	}
+	acpi_root_dir = acpi_device_dir(acpi_root);
+
+	/*
+	 * Install drivers required for proper enumeration of the
+	 * ACPI namespace.
+	 */
+	acpi_system_init();	/* ACPI System */
+	acpi_power_init();	/* ACPI Bus Power Management */
+#ifdef CONFIG_ACPI_EC
+	acpi_ec_init();		/* ACPI Embedded Controller */
+#endif
+#ifdef CONFIG_ACPI_PCI
+	acpi_pci_link_init();	/* ACPI PCI Interrupt Link */
+	acpi_pci_root_init();	/* ACPI PCI Root Bridge */
+#endif
+	/*
+	 * Enumerate devices in the ACPI namespace.
+	 */
+	result = acpi_bus_scan_fixed(acpi_root);
+	if (result)
+		goto error4;
+	result = acpi_bus_scan(acpi_root);
+	if (result)
+		goto error4;
+
+	return_VALUE(0);
+
+	/* Mimic structured exception handling */
+error4:
+	remove_proc_entry(ACPI_BUS_FILE_ROOT, NULL);
+error3:
+	acpi_bus_remove(acpi_root, ACPI_BUS_REMOVAL_NORMAL);
+error2:
+	acpi_remove_notify_handler(ACPI_ROOT_OBJECT,
+		ACPI_SYSTEM_NOTIFY, &acpi_bus_notify);
+error1:
+	acpi_terminate();
+error0:
+	return_VALUE(-ENODEV);
+}
+
+
+static void __exit
+acpi_bus_exit (void)
+{
+	acpi_status		status = AE_OK;
+
+	ACPI_FUNCTION_TRACE("acpi_bus_exit");
+
+	status = acpi_remove_notify_handler(ACPI_ROOT_OBJECT,
+		ACPI_SYSTEM_NOTIFY, acpi_bus_notify);
+	if (ACPI_FAILURE(status))
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+			"Error removing notify handler\n"));
+
+#ifdef CONFIG_ACPI_PCI
+	acpi_pci_root_exit();
+	acpi_pci_link_exit();
+#endif
+#ifdef CONFIG_ACPI_EC
+	acpi_ec_exit();
+#endif
+	acpi_power_exit();
+	acpi_system_exit();
+
+	acpi_bus_remove(acpi_root, ACPI_BUS_REMOVAL_NORMAL);
+
+	remove_proc_entry(ACPI_BUS_FILE_ROOT, NULL);
+
+	status = acpi_terminate();
+	if (ACPI_FAILURE(status))
+		printk(KERN_ERR PREFIX "Unable to terminate the ACPI Interpreter\n");
+	else
+		printk(KERN_ERR PREFIX "Interpreter disabled\n");
+
+	return_VOID;
+}
+
+
+int __init
+acpi_init (void)
+{
+	int			result = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_init");
+
+	printk(KERN_INFO PREFIX "Subsystem revision %08x\n",
+		ACPI_CA_VERSION);
+
+	/* Initial core debug level excludes drivers, so include them now */
+	acpi_set_debug(ACPI_DEBUG_LOW);
+
+	if (acpi_disabled) {
+		printk(KERN_INFO PREFIX "Interpreter disabled.\n");
+		return -ENODEV;
+	}
+
+#ifdef CONFIG_PM
+	if (PM_IS_ACTIVE()) {
+		printk(KERN_INFO PREFIX "APM is already active, exiting\n");
+		return -ENODEV;
+	}
+#endif
+
+	result = acpi_bus_init();
+	if (result)
+		return_VALUE(result);
+
+#ifdef CONFIG_PM
+	pm_active = 1;
+#endif
+
+	return_VALUE(0);
+}
+
+
+void __exit
+acpi_exit (void)
+{
+	ACPI_FUNCTION_TRACE("acpi_exit");
+
+#ifdef CONFIG_PM
+	pm_active = 0;
+#endif
+
+	acpi_bus_exit();
+
+	return_VOID;
+}
+
+
+int __init
+acpi_setup(char *str)
+{
+	while (str && *str) {
+		if (strncmp(str, "off", 3) == 0)
+			acpi_disabled = 1;
+		str = strchr(str, ',');
+		if (str)
+			str += strspn(str, ", \t");
+	}
+	return 1;
+}
+
+
+__setup("acpi=", acpi_setup);
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)