blob: 946610f00aa115c6c29520cfec73693ce748f8b5 [file] [log] [blame]
/*
* acpi_bus.c - ACPI Bus Driver ($Revision: 80 $)
*
* 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/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>
#include <linux/acpi.h>
#ifdef CONFIG_X86
#include <asm/mpspec.h>
#endif
#include <linux/pci.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
#include "internal.h"
#define _COMPONENT ACPI_BUS_COMPONENT
ACPI_MODULE_NAME("bus");
struct acpi_device *acpi_root;
struct proc_dir_entry *acpi_root_dir;
EXPORT_SYMBOL(acpi_root_dir);
#define STRUCT_TO_INT(s) (*((int*)&s))
static int set_power_nocheck(const struct dmi_system_id *id)
{
printk(KERN_NOTICE PREFIX "%s detected - "
"disable power check in power transistion\n", id->ident);
acpi_power_nocheck = 1;
return 0;
}
static struct dmi_system_id __cpuinitdata power_nocheck_dmi_table[] = {
{
set_power_nocheck, "HP Pavilion 05", {
DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
DMI_MATCH(DMI_SYS_VENDOR, "HP Pavilion 05"),
DMI_MATCH(DMI_PRODUCT_VERSION, "2001211RE101GLEND") }, NULL},
{},
};
/* --------------------------------------------------------------------------
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 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;
}
/*
* According to ACPI spec some device can be present and functional
* even if the parent is not present but functional.
* In such conditions the child device should not inherit the status
* from the parent.
*/
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) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]: "
"functional but not present;\n",
device->pnp.bus_id,
(u32) STRUCT_TO_INT(device->status)));
}
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);
void acpi_bus_private_data_handler(acpi_handle handle,
u32 function, void *context)
{
return;
}
EXPORT_SYMBOL(acpi_bus_private_data_handler);
int acpi_bus_get_private_data(acpi_handle handle, void **data)
{
acpi_status status = AE_OK;
if (!*data)
return -EINVAL;
status = acpi_get_data(handle, acpi_bus_private_data_handler, data);
if (ACPI_FAILURE(status) || !*data) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
handle));
return -ENODEV;
}
return 0;
}
EXPORT_SYMBOL(acpi_bus_get_private_data);
/* --------------------------------------------------------------------------
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 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
*/
if (!acpi_power_nocheck) {
/*
* Maybe the incorrect power state is returned on the bogus
* bios, which is different with the real power state.
* For example: the bios returns D0 state and the real power
* state is D3. OS expects to set the device to D0 state. In
* such case if OS uses the power state returned by the BIOS,
* the device can't be transisted to the correct power state.
* So if the acpi_power_nocheck is set, it is unnecessary to
* get the power state by calling acpi_bus_get_power.
*/
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);
bool acpi_bus_power_manageable(acpi_handle handle)
{
struct acpi_device *device;
int result;
result = acpi_bus_get_device(handle, &device);
return result ? false : device->flags.power_manageable;
}
EXPORT_SYMBOL(acpi_bus_power_manageable);
bool acpi_bus_can_wakeup(acpi_handle handle)
{
struct acpi_device *device;
int result;
result = acpi_bus_get_device(handle, &device);
return result ? false : device->wakeup.flags.valid;
}
EXPORT_SYMBOL(acpi_bus_can_wakeup);
/* --------------------------------------------------------------------------
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);
if (!list_empty(&acpi_bus_event_list)) {
entry = list_entry(acpi_bus_event_list.next,
struct acpi_bus_event, node);
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;
}
#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;
/*
* 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 0;
}
status = acpi_bus_get_status(device);
if (ACPI_FAILURE(status))
return -ENODEV;
if (STRUCT_TO_INT(old_status) == STRUCT_TO_INT(device->status))
return 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 0;
}
static int acpi_bus_check_scope(struct acpi_device *device)
{
int result = 0;
int status_changed = 0;
if (!device)
return -EINVAL;
/* Status Change? */
result = acpi_bus_check_device(device, &status_changed);
if (result)
return result;
if (!status_changed)
return 0;
/*
* TBD: Enumerate child devices within this device's scope and
* run acpi_bus_check_device()'s on them.
*/
return 0;
}
static BLOCKING_NOTIFIER_HEAD(acpi_bus_notify_list);
int register_acpi_bus_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_register(&acpi_bus_notify_list, nb);
}
EXPORT_SYMBOL_GPL(register_acpi_bus_notifier);
void unregister_acpi_bus_notifier(struct notifier_block *nb)
{
blocking_notifier_chain_unregister(&acpi_bus_notify_list, nb);
}
EXPORT_SYMBOL_GPL(unregister_acpi_bus_notifier);
/**
* 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;
blocking_notifier_call_chain(&acpi_bus_notify_list,
type, (void *)handle);
if (acpi_bus_get_device(handle, &device))
return;
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;
}
/* --------------------------------------------------------------------------
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;
/*
* 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;
case ACPI_IRQ_MODEL_PLATFORM:
message = "platform specific model";
break;
default:
printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
return -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_EXCEPTION((AE_INFO, status, "Evaluating _PIC"));
return -ENODEV;
}
return 0;
}
u8 acpi_gbl_permanent_mmap;
void __init acpi_early_init(void)
{
acpi_status status = AE_OK;
if (acpi_disabled)
return;
printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);
/* enable workarounds, unless strict ACPI spec. compliance */
if (!acpi_strict)
acpi_gbl_enable_interpreter_slack = TRUE;
acpi_gbl_permanent_mmap = 1;
status = acpi_reallocate_root_table();
if (ACPI_FAILURE(status)) {
printk(KERN_ERR PREFIX
"Unable to reallocate ACPI tables\n");
goto error0;
}
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;
}
#ifdef CONFIG_X86
if (!acpi_ioapic) {
/* compatible (0) means level (3) */
if (!(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)) {
acpi_sci_flags &= ~ACPI_MADT_TRIGGER_MASK;
acpi_sci_flags |= ACPI_MADT_TRIGGER_LEVEL;
}
/* Set PIC-mode SCI trigger type */
acpi_pic_sci_set_trigger(acpi_gbl_FADT.sci_interrupt,
(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
} else {
/*
* now that acpi_gbl_FADT is initialized,
* update it with result from INT_SRC_OVR parsing
*/
acpi_gbl_FADT.sci_interrupt = acpi_sci_override_gsi;
}
#endif
status =
acpi_enable_subsystem(~
(ACPI_NO_HARDWARE_INIT |
ACPI_NO_ACPI_ENABLE));
if (ACPI_FAILURE(status)) {
printk(KERN_ERR PREFIX "Unable to enable ACPI\n");
goto error0;
}
return;
error0:
disable_acpi();
return;
}
static int __init acpi_bus_init(void)
{
int result = 0;
acpi_status status = AE_OK;
extern acpi_status acpi_os_initialize1(void);
status = acpi_os_initialize1();
status =
acpi_enable_subsystem(ACPI_NO_HARDWARE_INIT | ACPI_NO_ACPI_ENABLE);
if (ACPI_FAILURE(status)) {
printk(KERN_ERR PREFIX
"Unable to start the ACPI Interpreter\n");
goto error1;
}
if (ACPI_FAILURE(status)) {
printk(KERN_ERR PREFIX
"Unable to initialize ACPI OS objects\n");
goto error1;
}
/*
* ACPI 2.0 requires the EC driver to be loaded and work before
* the EC device is found in the namespace (i.e. before acpi_initialize_objects()
* is called).
*
* This is accomplished by looking for the ECDT table, and getting
* the EC parameters out of that.
*/
status = acpi_ec_ecdt_probe();
/* Ignore result. Not having an ECDT is not fatal. */
status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
if (ACPI_FAILURE(status)) {
printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
goto error1;
}
/*
* Maybe EC region is required at bus_scan/acpi_get_devices. So it
* is necessary to enable it as early as possible.
*/
acpi_boot_ec_enable();
printk(KERN_INFO PREFIX "Interpreter enabled\n");
/* Initialize sleep structures */
acpi_sleep_init();
/*
* 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");
goto error1;
}
/*
* Create the top ACPI proc directory
*/
acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
return 0;
/* Mimic structured exception handling */
error1:
acpi_terminate();
return -ENODEV;
}
struct kobject *acpi_kobj;
static int __init acpi_init(void)
{
int result = 0;
if (acpi_disabled) {
printk(KERN_INFO PREFIX "Interpreter disabled.\n");
return -ENODEV;
}
acpi_kobj = kobject_create_and_add("acpi", firmware_kobj);
if (!acpi_kobj) {
printk(KERN_WARNING "%s: kset create error\n", __func__);
acpi_kobj = NULL;
}
result = acpi_bus_init();
if (!result) {
pci_mmcfg_late_init();
if (!(pm_flags & PM_APM))
pm_flags |= PM_ACPI;
else {
printk(KERN_INFO PREFIX
"APM is already active, exiting\n");
disable_acpi();
result = -ENODEV;
}
} else
disable_acpi();
if (acpi_disabled)
return result;
/*
* If the laptop falls into the DMI check table, the power state check
* will be disabled in the course of device power transistion.
*/
dmi_check_system(power_nocheck_dmi_table);
acpi_scan_init();
acpi_ec_init();
acpi_power_init();
return result;
}
subsys_initcall(acpi_init);