scan.c

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/*
 * scan.c - support for transforming the ACPI namespace into individual objects
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/acpi.h>
#include <linux/signal.h>
#include <linux/kthread.h>
#include <linux/dmi.h>
#include <linux/nls.h>

#include <acpi/acpi_drivers.h>

#include "internal.h"

#define _COMPONENT      ACPI_BUS_COMPONENT
ACPI_MODULE_NAME("scan");
#define STRUCT_TO_INT(s)    (*((int*)&s))
extern struct acpi_device *acpi_root;

#define ACPI_BUS_CLASS          "system_bus"
#define ACPI_BUS_HID            "LNXSYBUS"
#define ACPI_BUS_DEVICE_NAME        "System Bus"

#define ACPI_IS_ROOT_DEVICE(device)    (!(device)->parent)

static const char *dummy_hid = "device";

static LIST_HEAD(acpi_device_list);
static LIST_HEAD(acpi_bus_id_list);
DEFINE_MUTEX(acpi_device_lock);
LIST_HEAD(acpi_wakeup_device_list);

struct acpi_device_bus_id{
    char bus_id[15];
    unsigned int instance_no;
    struct list_head node;
};

/*
 * Creates hid/cid(s) string needed for modalias and uevent
 * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
 * char *modalias: "acpi:IBM0001:ACPI0001"
*/
static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
               int size)
{
    int len;
    int count;
    struct acpi_hardware_id *id;

    if (list_empty(&acpi_dev->pnp.ids))
        return 0;

    len = snprintf(modalias, size, "acpi:");
    size -= len;

    list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
        count = snprintf(&modalias[len], size, "%s:", id->id);
        if (count < 0 || count >= size)
            return -EINVAL;
        len += count;
        size -= count;
    }

    modalias[len] = '\0';
    return len;
}

static ssize_t
acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
    struct acpi_device *acpi_dev = to_acpi_device(dev);
    int len;

    /* Device has no HID and no CID or string is >1024 */
    len = create_modalias(acpi_dev, buf, 1024);
    if (len <= 0)
        return 0;
    buf[len++] = '\n';
    return len;
}
static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);

void acpi_bus_hot_remove_device(void *context)
{
    struct acpi_eject_event *ej_event = (struct acpi_eject_event *) context;
    struct acpi_device *device;
    acpi_handle handle = ej_event->handle;
    struct acpi_object_list arg_list;
    union acpi_object arg;
    acpi_status status = AE_OK;
    u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */

    if (acpi_bus_get_device(handle, &device))
        goto err_out;

    if (!device)
        goto err_out;

    ACPI_DEBUG_PRINT((ACPI_DB_INFO,
        "Hot-removing device %s...\n", dev_name(&device->dev)));

    if (acpi_bus_trim(device, 1)) {
        printk(KERN_ERR PREFIX
                "Removing device failed\n");
        goto err_out;
    }

    /* power off device */
    status = acpi_evaluate_object(handle, "_PS3", NULL, NULL);
    if (ACPI_FAILURE(status) && status != AE_NOT_FOUND)
        printk(KERN_WARNING PREFIX
                "Power-off device failed\n");

    if (device->flags.lockable) {
        arg_list.count = 1;
        arg_list.pointer = &arg;
        arg.type = ACPI_TYPE_INTEGER;
        arg.integer.value = 0;
        acpi_evaluate_object(handle, "_LCK", &arg_list, NULL);
    }

    arg_list.count = 1;
    arg_list.pointer = &arg;
    arg.type = ACPI_TYPE_INTEGER;
    arg.integer.value = 1;

    /*
     * TBD: _EJD support.
     */
    status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL);
    if (ACPI_FAILURE(status)) {
        if (status != AE_NOT_FOUND)
            printk(KERN_WARNING PREFIX
                    "Eject device failed\n");
        goto err_out;
    }

    kfree(context);
    return;

err_out:
    /* Inform firmware the hot-remove operation has completed w/ error */
    (void) acpi_evaluate_hotplug_ost(handle,
                ej_event->event, ost_code, NULL);
    kfree(context);
    return;
}

static ssize_t
acpi_eject_store(struct device *d, struct device_attribute *attr,
        const char *buf, size_t count)
{
    int ret = count;
    acpi_status status;
    acpi_object_type type = 0;
    struct acpi_device *acpi_device = to_acpi_device(d);
    struct acpi_eject_event *ej_event;

    if ((!count) || (buf[0] != '1')) {
        return -EINVAL;
    }
#ifndef FORCE_EJECT
    if (acpi_device->driver == NULL) {
        ret = -ENODEV;
        goto err;
    }
#endif
    status = acpi_get_type(acpi_device->handle, &type);
    if (ACPI_FAILURE(status) || (!acpi_device->flags.ejectable)) {
        ret = -ENODEV;
        goto err;
    }

    ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
    if (!ej_event) {
        ret = -ENOMEM;
        goto err;
    }

    ej_event->handle = acpi_device->handle;
    if (acpi_device->flags.eject_pending) {
        /* event originated from ACPI eject notification */
        ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
        acpi_device->flags.eject_pending = 0;
    } else {
        /* event originated from user */
        ej_event->event = ACPI_OST_EC_OSPM_EJECT;
        (void) acpi_evaluate_hotplug_ost(ej_event->handle,
            ej_event->event, ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
    }

    acpi_os_hotplug_execute(acpi_bus_hot_remove_device, (void *)ej_event);
err:
    return ret;
}

static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);

static ssize_t
acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
    struct acpi_device *acpi_dev = to_acpi_device(dev);

    return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
}
static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);

static ssize_t
acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
    struct acpi_device *acpi_dev = to_acpi_device(dev);
    struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
    int result;

    result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
    if (result)
        goto end;

    result = sprintf(buf, "%s\n", (char*)path.pointer);
    kfree(path.pointer);
end:
    return result;
}
static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);

/* sysfs file that shows description text from the ACPI _STR method */
static ssize_t description_show(struct device *dev,
                struct device_attribute *attr,
                char *buf) {
    struct acpi_device *acpi_dev = to_acpi_device(dev);
    int result;

    if (acpi_dev->pnp.str_obj == NULL)
        return 0;

    /*
     * The _STR object contains a Unicode identifier for a device.
     * We need to convert to utf-8 so it can be displayed.
     */
    result = utf16s_to_utf8s(
        (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
        acpi_dev->pnp.str_obj->buffer.length,
        UTF16_LITTLE_ENDIAN, buf,
        PAGE_SIZE);

    buf[result++] = '\n';

    return result;
}
static DEVICE_ATTR(description, 0444, description_show, NULL);

static int acpi_device_setup_files(struct acpi_device *dev)
{
    struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
    acpi_status status;
    acpi_handle temp;
    int result = 0;

    /*
     * Devices gotten from FADT don't have a "path" attribute
     */
    if (dev->handle) {
        result = device_create_file(&dev->dev, &dev_attr_path);
        if (result)
            goto end;
    }

    if (!list_empty(&dev->pnp.ids)) {
        result = device_create_file(&dev->dev, &dev_attr_hid);
        if (result)
            goto end;

        result = device_create_file(&dev->dev, &dev_attr_modalias);
        if (result)
            goto end;
    }

    /*
     * If device has _STR, 'description' file is created
     */
    status = acpi_get_handle(dev->handle, "_STR", &temp);
    if (ACPI_SUCCESS(status)) {
        status = acpi_evaluate_object(dev->handle, "_STR",
                    NULL, &buffer);
        if (ACPI_FAILURE(status))
            buffer.pointer = NULL;
        dev->pnp.str_obj = buffer.pointer;
        result = device_create_file(&dev->dev, &dev_attr_description);
        if (result)
            goto end;
    }

        /*
         * If device has _EJ0, 'eject' file is created that is used to trigger
         * hot-removal function from userland.
         */
    status = acpi_get_handle(dev->handle, "_EJ0", &temp);
    if (ACPI_SUCCESS(status))
        result = device_create_file(&dev->dev, &dev_attr_eject);
end:
    return result;
}

static void acpi_device_remove_files(struct acpi_device *dev)
{
    acpi_status status;
    acpi_handle temp;

    /*
     * If device has _STR, remove 'description' file
     */
    status = acpi_get_handle(dev->handle, "_STR", &temp);
    if (ACPI_SUCCESS(status)) {
        kfree(dev->pnp.str_obj);
        device_remove_file(&dev->dev, &dev_attr_description);
    }
    /*
     * If device has _EJ0, remove 'eject' file.
     */
    status = acpi_get_handle(dev->handle, "_EJ0", &temp);
    if (ACPI_SUCCESS(status))
        device_remove_file(&dev->dev, &dev_attr_eject);

    device_remove_file(&dev->dev, &dev_attr_modalias);
    device_remove_file(&dev->dev, &dev_attr_hid);
    if (dev->handle)
        device_remove_file(&dev->dev, &dev_attr_path);
}
/* --------------------------------------------------------------------------
            ACPI Bus operations
   -------------------------------------------------------------------------- */

int acpi_match_device_ids(struct acpi_device *device,
              const struct acpi_device_id *ids)
{
    const struct acpi_device_id *id;
    struct acpi_hardware_id *hwid;

    /*
     * If the device is not present, it is unnecessary to load device
     * driver for it.
     */
    if (!device->status.present)
        return -ENODEV;

    for (id = ids; id->id[0]; id++)
        list_for_each_entry(hwid, &device->pnp.ids, list)
            if (!strcmp((char *) id->id, hwid->id))
                return 0;

    return -ENOENT;
}
EXPORT_SYMBOL(acpi_match_device_ids);

static void acpi_free_ids(struct acpi_device *device)
{
    struct acpi_hardware_id *id, *tmp;

    list_for_each_entry_safe(id, tmp, &device->pnp.ids, list) {
        kfree(id->id);
        kfree(id);
    }
}

static void acpi_device_release(struct device *dev)
{
    struct acpi_device *acpi_dev = to_acpi_device(dev);

    acpi_free_ids(acpi_dev);
    kfree(acpi_dev);
}

static int acpi_bus_match(struct device *dev, struct device_driver *drv)
{
    struct acpi_device *acpi_dev = to_acpi_device(dev);
    struct acpi_driver *acpi_drv = to_acpi_driver(drv);

    return !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
}

static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
{
    struct acpi_device *acpi_dev = to_acpi_device(dev);
    int len;

    if (list_empty(&acpi_dev->pnp.ids))
        return 0;

    if (add_uevent_var(env, "MODALIAS="))
        return -ENOMEM;
    len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
                  sizeof(env->buf) - env->buflen);
    if (len >= (sizeof(env->buf) - env->buflen))
        return -ENOMEM;
    env->buflen += len;
    return 0;
}

static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
{
    struct acpi_device *device = data;

    device->driver->ops.notify(device, event);
}

static acpi_status acpi_device_notify_fixed(void *data)
{
    struct acpi_device *device = data;

    /* Fixed hardware devices have no handles */
    acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
    return AE_OK;
}

static int acpi_device_install_notify_handler(struct acpi_device *device)
{
    acpi_status status;

    if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
        status =
            acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
                             acpi_device_notify_fixed,
                             device);
    else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
        status =
            acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
                             acpi_device_notify_fixed,
                             device);
    else
        status = acpi_install_notify_handler(device->handle,
                             ACPI_DEVICE_NOTIFY,
                             acpi_device_notify,
                             device);

    if (ACPI_FAILURE(status))
        return -EINVAL;
    return 0;
}

static void acpi_device_remove_notify_handler(struct acpi_device *device)
{
    if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
        acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
                        acpi_device_notify_fixed);
    else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
        acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
                        acpi_device_notify_fixed);
    else
        acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
                       acpi_device_notify);
}

static int acpi_bus_driver_init(struct acpi_device *, struct acpi_driver *);
static int acpi_start_single_object(struct acpi_device *);
static int acpi_device_probe(struct device * dev)
{
    struct acpi_device *acpi_dev = to_acpi_device(dev);
    struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
    int ret;

    ret = acpi_bus_driver_init(acpi_dev, acpi_drv);
    if (!ret) {
        if (acpi_dev->bus_ops.acpi_op_start)
            acpi_start_single_object(acpi_dev);

        if (acpi_drv->ops.notify) {
            ret = acpi_device_install_notify_handler(acpi_dev);
            if (ret) {
                if (acpi_drv->ops.remove)
                    acpi_drv->ops.remove(acpi_dev,
                             acpi_dev->removal_type);
                return ret;
            }
        }

        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
            "Found driver [%s] for device [%s]\n",
            acpi_drv->name, acpi_dev->pnp.bus_id));
        get_device(dev);
    }
    return ret;
}

static int acpi_device_remove(struct device * dev)
{
    struct acpi_device *acpi_dev = to_acpi_device(dev);
    struct acpi_driver *acpi_drv = acpi_dev->driver;

    if (acpi_drv) {
        if (acpi_drv->ops.notify)
            acpi_device_remove_notify_handler(acpi_dev);
        if (acpi_drv->ops.remove)
            acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type);
    }
    acpi_dev->driver = NULL;
    acpi_dev->driver_data = NULL;

    put_device(dev);
    return 0;
}

struct bus_type acpi_bus_type = {
    .name       = "acpi",
    .match      = acpi_bus_match,
    .probe      = acpi_device_probe,
    .remove     = acpi_device_remove,
    .uevent     = acpi_device_uevent,
};

static int acpi_device_register(struct acpi_device *device)
{
    int result;
    struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
    int found = 0;

    /*
     * Linkage
     * -------
     * Link this device to its parent and siblings.
     */
    INIT_LIST_HEAD(&device->children);
    INIT_LIST_HEAD(&device->node);
    INIT_LIST_HEAD(&device->wakeup_list);
    INIT_LIST_HEAD(&device->physical_node_list);
    mutex_init(&device->physical_node_lock);

    new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
    if (!new_bus_id) {
        printk(KERN_ERR PREFIX "Memory allocation error\n");
        return -ENOMEM;
    }

    mutex_lock(&acpi_device_lock);
    /*
     * Find suitable bus_id and instance number in acpi_bus_id_list
     * If failed, create one and link it into acpi_bus_id_list
     */
    list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
        if (!strcmp(acpi_device_bus_id->bus_id,
                acpi_device_hid(device))) {
            acpi_device_bus_id->instance_no++;
            found = 1;
            kfree(new_bus_id);
            break;
        }
    }
    if (!found) {
        acpi_device_bus_id = new_bus_id;
        strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
        acpi_device_bus_id->instance_no = 0;
        list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
    }
    dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);

    if (device->parent)
        list_add_tail(&device->node, &device->parent->children);

    if (device->wakeup.flags.valid)
        list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
    mutex_unlock(&acpi_device_lock);

    if (device->parent)
        device->dev.parent = &device->parent->dev;
    device->dev.bus = &acpi_bus_type;
    device->dev.release = &acpi_device_release;
    result = device_register(&device->dev);
    if (result) {
        dev_err(&device->dev, "Error registering device\n");
        goto end;
    }

    result = acpi_device_setup_files(device);
    if (result)
        printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
               dev_name(&device->dev));

    device->removal_type = ACPI_BUS_REMOVAL_NORMAL;
    return 0;
end:
    mutex_lock(&acpi_device_lock);
    if (device->parent)
        list_del(&device->node);
    list_del(&device->wakeup_list);
    mutex_unlock(&acpi_device_lock);
    return result;
}

static void acpi_device_unregister(struct acpi_device *device, int type)
{
    mutex_lock(&acpi_device_lock);
    if (device->parent)
        list_del(&device->node);

    list_del(&device->wakeup_list);
    mutex_unlock(&acpi_device_lock);

    acpi_detach_data(device->handle, acpi_bus_data_handler);

    acpi_device_remove_files(device);
    device_unregister(&device->dev);
}

/* --------------------------------------------------------------------------
                                 Driver Management
   -------------------------------------------------------------------------- */
static int
acpi_bus_driver_init(struct acpi_device *device, struct acpi_driver *driver)
{
    int result = 0;

    if (!device || !driver)
        return -EINVAL;

    if (!driver->ops.add)
        return -ENOSYS;

    result = driver->ops.add(device);
    if (result) {
        device->driver = NULL;
        device->driver_data = NULL;
        return result;
    }

    device->driver = driver;

    /*
     * TBD - Configuration Management: Assign resources to device based
     * upon possible configuration and currently allocated resources.
     */

    ACPI_DEBUG_PRINT((ACPI_DB_INFO,
              "Driver successfully bound to device\n"));
    return 0;
}

static int acpi_start_single_object(struct acpi_device *device)
{
    int result = 0;
    struct acpi_driver *driver;


    if (!(driver = device->driver))
        return 0;

    if (driver->ops.start) {
        result = driver->ops.start(device);
        if (result && driver->ops.remove)
            driver->ops.remove(device, ACPI_BUS_REMOVAL_NORMAL);
    }

    return result;
}

int acpi_bus_register_driver(struct acpi_driver *driver)
{
    int ret;

    if (acpi_disabled)
        return -ENODEV;
    driver->drv.name = driver->name;
    driver->drv.bus = &acpi_bus_type;
    driver->drv.owner = driver->owner;

    ret = driver_register(&driver->drv);
    return ret;
}

EXPORT_SYMBOL(acpi_bus_register_driver);

void acpi_bus_unregister_driver(struct acpi_driver *driver)
{
    driver_unregister(&driver->drv);
}

EXPORT_SYMBOL(acpi_bus_unregister_driver);

/* --------------------------------------------------------------------------
                                 Device Enumeration
   -------------------------------------------------------------------------- */
static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
{
    acpi_status status;
    int ret;
    struct acpi_device *device;

    /*
     * Fixed hardware devices do not appear in the namespace and do not
     * have handles, but we fabricate acpi_devices for them, so we have
     * to deal with them specially.
     */
    if (handle == NULL)
        return acpi_root;

    do {
        status = acpi_get_parent(handle, &handle);
        if (status == AE_NULL_ENTRY)
            return NULL;
        if (ACPI_FAILURE(status))
            return acpi_root;

        ret = acpi_bus_get_device(handle, &device);
        if (ret == 0)
            return device;
    } while (1);
}

acpi_status
acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
{
    acpi_status status;
    acpi_handle tmp;
    struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
    union acpi_object *obj;

    status = acpi_get_handle(handle, "_EJD", &tmp);
    if (ACPI_FAILURE(status))
        return status;

    status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
    if (ACPI_SUCCESS(status)) {
        obj = buffer.pointer;
        status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
                     ejd);
        kfree(buffer.pointer);
    }
    return status;
}
EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);

void acpi_bus_data_handler(acpi_handle handle, void *context)
{

    /* TBD */

    return;
}

static int acpi_bus_get_perf_flags(struct acpi_device *device)
{
    device->performance.state = ACPI_STATE_UNKNOWN;
    return 0;
}

static acpi_status
acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
                         struct acpi_device_wakeup *wakeup)
{
    struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
    union acpi_object *package = NULL;
    union acpi_object *element = NULL;
    acpi_status status;
    int i = 0;

    if (!wakeup)
        return AE_BAD_PARAMETER;

    /* _PRW */
    status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
    if (ACPI_FAILURE(status)) {
        ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
        return status;
    }

    package = (union acpi_object *)buffer.pointer;

    if (!package || (package->package.count < 2)) {
        status = AE_BAD_DATA;
        goto out;
    }

    element = &(package->package.elements[0]);
    if (!element) {
        status = AE_BAD_DATA;
        goto out;
    }
    if (element->type == ACPI_TYPE_PACKAGE) {
        if ((element->package.count < 2) ||
            (element->package.elements[0].type !=
             ACPI_TYPE_LOCAL_REFERENCE)
            || (element->package.elements[1].type != ACPI_TYPE_INTEGER)) {
            status = AE_BAD_DATA;
            goto out;
        }
        wakeup->gpe_device =
            element->package.elements[0].reference.handle;
        wakeup->gpe_number =
            (u32) element->package.elements[1].integer.value;
    } else if (element->type == ACPI_TYPE_INTEGER) {
        wakeup->gpe_device = NULL;
        wakeup->gpe_number = element->integer.value;
    } else {
        status = AE_BAD_DATA;
        goto out;
    }

    element = &(package->package.elements[1]);
    if (element->type != ACPI_TYPE_INTEGER) {
        status = AE_BAD_DATA;
        goto out;
    }
    wakeup->sleep_state = element->integer.value;

    if ((package->package.count - 2) > ACPI_MAX_HANDLES) {
        status = AE_NO_MEMORY;
        goto out;
    }
    wakeup->resources.count = package->package.count - 2;
    for (i = 0; i < wakeup->resources.count; i++) {
        element = &(package->package.elements[i + 2]);
        if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
            status = AE_BAD_DATA;
            goto out;
        }

        wakeup->resources.handles[i] = element->reference.handle;
    }

    acpi_setup_gpe_for_wake(handle, wakeup->gpe_device, wakeup->gpe_number);

 out:
    kfree(buffer.pointer);

    return status;
}

static void acpi_bus_set_run_wake_flags(struct acpi_device *device)
{
    struct acpi_device_id button_device_ids[] = {
        {"PNP0C0D", 0},
        {"PNP0C0C", 0},
        {"PNP0C0E", 0},
        {"", 0},
    };
    acpi_status status;
    acpi_event_status event_status;

    device->wakeup.flags.notifier_present = 0;

    /* Power button, Lid switch always enable wakeup */
    if (!acpi_match_device_ids(device, button_device_ids)) {
        device->wakeup.flags.run_wake = 1;
        device_set_wakeup_capable(&device->dev, true);
        return;
    }

    status = acpi_get_gpe_status(device->wakeup.gpe_device,
                    device->wakeup.gpe_number,
                        &event_status);
    if (status == AE_OK)
        device->wakeup.flags.run_wake =
                !!(event_status & ACPI_EVENT_FLAG_HANDLE);
}

static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
{
    acpi_handle temp;
    acpi_status status = 0;
    int psw_error;

    /* Presence of _PRW indicates wake capable */
    status = acpi_get_handle(device->handle, "_PRW", &temp);
    if (ACPI_FAILURE(status))
        return;

    status = acpi_bus_extract_wakeup_device_power_package(device->handle,
                                  &device->wakeup);
    if (ACPI_FAILURE(status)) {
        ACPI_EXCEPTION((AE_INFO, status, "Extracting _PRW package"));
        return;
    }

    device->wakeup.flags.valid = 1;
    device->wakeup.prepare_count = 0;
    acpi_bus_set_run_wake_flags(device);
    /* Call _PSW/_DSW object to disable its ability to wake the sleeping
     * system for the ACPI device with the _PRW object.
     * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
     * So it is necessary to call _DSW object first. Only when it is not
     * present will the _PSW object used.
     */
    psw_error = acpi_device_sleep_wake(device, 0, 0, 0);
    if (psw_error)
        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                "error in _DSW or _PSW evaluation\n"));
}

static void acpi_bus_add_power_resource(acpi_handle handle);

static int acpi_bus_get_power_flags(struct acpi_device *device)
{
    acpi_status status = 0;
    acpi_handle handle = NULL;
    u32 i = 0;


    /*
     * 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;

    /*
     * Enumerate supported power management states
     */
    for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; 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) {
            int j;

            device->power.flags.power_resources = 1;
            for (j = 0; j < ps->resources.count; j++)
                acpi_bus_add_power_resource(ps->resources.handles[j]);
        }

        /* 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;

        /*
         * State is valid if there are means to put the device into it.
         * D3hot is only valid if _PR3 present.
         */
        if (ps->resources.count ||
            (ps->flags.explicit_set && i < ACPI_STATE_D3_HOT))
            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;

    /* Set D3cold's explicit_set flag if _PS3 exists. */
    if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set)
        device->power.states[ACPI_STATE_D3_COLD].flags.explicit_set = 1;

    acpi_bus_init_power(device);

    return 0;
}

static int acpi_bus_get_flags(struct acpi_device *device)
{
    acpi_status status = AE_OK;
    acpi_handle temp = NULL;


    /* 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 _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;

    /* Power resources cannot be power manageable. */
    if (device->device_type == ACPI_BUS_TYPE_POWER)
        return 0;

    /* 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: Performance management */

    return 0;
}

static void acpi_device_get_busid(struct acpi_device *device)
{
    char bus_id[5] = { '?', 0 };
    struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
    int i = 0;

    /*
     * Bus ID
     * ------
     * The device's Bus ID is simply the object name.
     * TBD: Shouldn't this value be unique (within the ACPI namespace)?
     */
    if (ACPI_IS_ROOT_DEVICE(device)) {
        strcpy(device->pnp.bus_id, "ACPI");
        return;
    }

    switch (device->device_type) {
    case ACPI_BUS_TYPE_POWER_BUTTON:
        strcpy(device->pnp.bus_id, "PWRF");
        break;
    case ACPI_BUS_TYPE_SLEEP_BUTTON:
        strcpy(device->pnp.bus_id, "SLPF");
        break;
    default:
        acpi_get_name(device->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;
        }
        strcpy(device->pnp.bus_id, bus_id);
        break;
    }
}

/*
 * acpi_bay_match - see if a device is an ejectable driver bay
 *
 * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
 * then we can safely call it an ejectable drive bay
 */
static int acpi_bay_match(struct acpi_device *device){
    acpi_status status;
    acpi_handle handle;
    acpi_handle tmp;
    acpi_handle phandle;

    handle = device->handle;

    status = acpi_get_handle(handle, "_EJ0", &tmp);
    if (ACPI_FAILURE(status))
        return -ENODEV;

    if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
        (ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
        (ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
        (ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
        return 0;

    if (acpi_get_parent(handle, &phandle))
        return -ENODEV;

        if ((ACPI_SUCCESS(acpi_get_handle(phandle, "_GTF", &tmp))) ||
                (ACPI_SUCCESS(acpi_get_handle(phandle, "_GTM", &tmp))) ||
                (ACPI_SUCCESS(acpi_get_handle(phandle, "_STM", &tmp))) ||
                (ACPI_SUCCESS(acpi_get_handle(phandle, "_SDD", &tmp))))
                return 0;

    return -ENODEV;
}

/*
 * acpi_dock_match - see if a device has a _DCK method
 */
static int acpi_dock_match(struct acpi_device *device)
{
    acpi_handle tmp;
    return acpi_get_handle(device->handle, "_DCK", &tmp);
}

const char *acpi_device_hid(struct acpi_device *device)
{
    struct acpi_hardware_id *hid;

    if (list_empty(&device->pnp.ids))
        return dummy_hid;

    hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
    return hid->id;
}
EXPORT_SYMBOL(acpi_device_hid);

static void acpi_add_id(struct acpi_device *device, const char *dev_id)
{
    struct acpi_hardware_id *id;

    id = kmalloc(sizeof(*id), GFP_KERNEL);
    if (!id)
        return;

    id->id = kstrdup(dev_id, GFP_KERNEL);
    if (!id->id) {
        kfree(id);
        return;
    }

    list_add_tail(&id->list, &device->pnp.ids);
}

/*
 * Old IBM workstations have a DSDT bug wherein the SMBus object
 * lacks the SMBUS01 HID and the methods do not have the necessary "_"
 * prefix.  Work around this.
 */
static int acpi_ibm_smbus_match(struct acpi_device *device)
{
    acpi_handle h_dummy;
    struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
    int result;

    if (!dmi_name_in_vendors("IBM"))
        return -ENODEV;

    /* Look for SMBS object */
    result = acpi_get_name(device->handle, ACPI_SINGLE_NAME, &path);
    if (result)
        return result;

    if (strcmp("SMBS", path.pointer)) {
        result = -ENODEV;
        goto out;
    }

    /* Does it have the necessary (but misnamed) methods? */
    result = -ENODEV;
    if (ACPI_SUCCESS(acpi_get_handle(device->handle, "SBI", &h_dummy)) &&
        ACPI_SUCCESS(acpi_get_handle(device->handle, "SBR", &h_dummy)) &&
        ACPI_SUCCESS(acpi_get_handle(device->handle, "SBW", &h_dummy)))
        result = 0;
out:
    kfree(path.pointer);
    return result;
}

static void acpi_device_set_id(struct acpi_device *device)
{
    acpi_status status;
    struct acpi_device_info *info;
    struct acpica_device_id_list *cid_list;
    int i;

    switch (device->device_type) {
    case ACPI_BUS_TYPE_DEVICE:
        if (ACPI_IS_ROOT_DEVICE(device)) {
            acpi_add_id(device, ACPI_SYSTEM_HID);
            break;
        }

        status = acpi_get_object_info(device->handle, &info);
        if (ACPI_FAILURE(status)) {
            printk(KERN_ERR PREFIX "%s: Error reading device info\n", __func__);
            return;
        }

        if (info->valid & ACPI_VALID_HID)
            acpi_add_id(device, info->hardware_id.string);
        if (info->valid & ACPI_VALID_CID) {
            cid_list = &info->compatible_id_list;
            for (i = 0; i < cid_list->count; i++)
                acpi_add_id(device, cid_list->ids[i].string);
        }
        if (info->valid & ACPI_VALID_ADR) {
            device->pnp.bus_address = info->address;
            device->flags.bus_address = 1;
        }

        kfree(info);

        /*
         * Some devices don't reliably have _HIDs & _CIDs, so add
         * synthetic HIDs to make sure drivers can find them.
         */
        if (acpi_is_video_device(device))
            acpi_add_id(device, ACPI_VIDEO_HID);
        else if (ACPI_SUCCESS(acpi_bay_match(device)))
            acpi_add_id(device, ACPI_BAY_HID);
        else if (ACPI_SUCCESS(acpi_dock_match(device)))
            acpi_add_id(device, ACPI_DOCK_HID);
        else if (!acpi_ibm_smbus_match(device))
            acpi_add_id(device, ACPI_SMBUS_IBM_HID);
        else if (!acpi_device_hid(device) &&
             ACPI_IS_ROOT_DEVICE(device->parent)) {
            acpi_add_id(device, ACPI_BUS_HID); /* \_SB, LNXSYBUS */
            strcpy(device->pnp.device_name, ACPI_BUS_DEVICE_NAME);
            strcpy(device->pnp.device_class, ACPI_BUS_CLASS);
        }

        break;
    case ACPI_BUS_TYPE_POWER:
        acpi_add_id(device, ACPI_POWER_HID);
        break;
    case ACPI_BUS_TYPE_PROCESSOR:
        acpi_add_id(device, ACPI_PROCESSOR_OBJECT_HID);
        break;
    case ACPI_BUS_TYPE_THERMAL:
        acpi_add_id(device, ACPI_THERMAL_HID);
        break;
    case ACPI_BUS_TYPE_POWER_BUTTON:
        acpi_add_id(device, ACPI_BUTTON_HID_POWERF);
        break;
    case ACPI_BUS_TYPE_SLEEP_BUTTON:
        acpi_add_id(device, ACPI_BUTTON_HID_SLEEPF);
        break;
    }
}

static int acpi_device_set_context(struct acpi_device *device)
{
    acpi_status status;

    /*
     * Context
     * -------
     * Attach this 'struct acpi_device' to the ACPI object.  This makes
     * resolutions from handle->device very efficient.  Fixed hardware
     * devices have no handles, so we skip them.
     */
    if (!device->handle)
        return 0;

    status = acpi_attach_data(device->handle,
                  acpi_bus_data_handler, device);
    if (ACPI_SUCCESS(status))
        return 0;

    printk(KERN_ERR PREFIX "Error attaching device data\n");
    return -ENODEV;
}

static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
{
    if (!dev)
        return -EINVAL;

    dev->removal_type = ACPI_BUS_REMOVAL_EJECT;
    device_release_driver(&dev->dev);

    if (!rmdevice)
        return 0;

    /*
     * unbind _ADR-Based Devices when hot removal
     */
    if (dev->flags.bus_address) {
        if ((dev->parent) && (dev->parent->ops.unbind))
            dev->parent->ops.unbind(dev);
    }
    acpi_device_unregister(dev, ACPI_BUS_REMOVAL_EJECT);

    return 0;
}

static int acpi_add_single_object(struct acpi_device **child,
                  acpi_handle handle, int type,
                  unsigned long long sta,
                  struct acpi_bus_ops *ops)
{
    int result;
    struct acpi_device *device;
    struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

    device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
    if (!device) {
        printk(KERN_ERR PREFIX "Memory allocation error\n");
        return -ENOMEM;
    }

    INIT_LIST_HEAD(&device->pnp.ids);
    device->device_type = type;
    device->handle = handle;
    device->parent = acpi_bus_get_parent(handle);
    device->bus_ops = *ops; /* workround for not call .start */
    STRUCT_TO_INT(device->status) = sta;

    acpi_device_get_busid(device);

    /*
     * Flags
     * -----
     * 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;

    /*
     * Initialize Device
     * -----------------
     * TBD: Synch with Core's enumeration/initialization process.
     */
    acpi_device_set_id(device);

    /*
     * Power Management
     * ----------------
     */
    if (device->flags.power_manageable) {
        result = acpi_bus_get_power_flags(device);
        if (result)
            goto end;
    }

    /*
     * Wakeup device management
     *-----------------------
     */
    acpi_bus_get_wakeup_device_flags(device);

    /*
     * Performance Management
     * ----------------------
     */
    if (device->flags.performance_manageable) {
        result = acpi_bus_get_perf_flags(device);
        if (result)
            goto end;
    }

    if ((result = acpi_device_set_context(device)))
        goto end;

    result = acpi_device_register(device);

    /*
     * Bind _ADR-Based Devices when hot add
     */
    if (device->flags.bus_address) {
        if (device->parent && device->parent->ops.bind)
            device->parent->ops.bind(device);
    }

end:
    if (!result) {
        acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
            "Adding %s [%s] parent %s\n", dev_name(&device->dev),
             (char *) buffer.pointer,
             device->parent ? dev_name(&device->parent->dev) :
                      "(null)"));
        kfree(buffer.pointer);
        *child = device;
    } else
        acpi_device_release(&device->dev);

    return result;
}

#define ACPI_STA_DEFAULT (ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED | \
              ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING)

static void acpi_bus_add_power_resource(acpi_handle handle)
{
    struct acpi_bus_ops ops = {
        .acpi_op_add = 1,
        .acpi_op_start = 1,
    };
    struct acpi_device *device = NULL;

    acpi_bus_get_device(handle, &device);
    if (!device)
        acpi_add_single_object(&device, handle, ACPI_BUS_TYPE_POWER,
                    ACPI_STA_DEFAULT, &ops);
}

static int acpi_bus_type_and_status(acpi_handle handle, int *type,
                    unsigned long long *sta)
{
    acpi_status status;
    acpi_object_type acpi_type;

    status = acpi_get_type(handle, &acpi_type);
    if (ACPI_FAILURE(status))
        return -ENODEV;

    switch (acpi_type) {
    case ACPI_TYPE_ANY:     /* for ACPI_ROOT_OBJECT */
    case ACPI_TYPE_DEVICE:
        *type = ACPI_BUS_TYPE_DEVICE;
        status = acpi_bus_get_status_handle(handle, sta);
        if (ACPI_FAILURE(status))
            return -ENODEV;
        break;
    case ACPI_TYPE_PROCESSOR:
        *type = ACPI_BUS_TYPE_PROCESSOR;
        status = acpi_bus_get_status_handle(handle, sta);
        if (ACPI_FAILURE(status))
            return -ENODEV;
        break;
    case ACPI_TYPE_THERMAL:
        *type = ACPI_BUS_TYPE_THERMAL;
        *sta = ACPI_STA_DEFAULT;
        break;
    case ACPI_TYPE_POWER:
        *type = ACPI_BUS_TYPE_POWER;
        *sta = ACPI_STA_DEFAULT;
        break;
    default:
        return -ENODEV;
    }

    return 0;
}

static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl,
                      void *context, void **return_value)
{
    struct acpi_bus_ops *ops = context;
    int type;
    unsigned long long sta;
    struct acpi_device *device;
    acpi_status status;
    int result;

    result = acpi_bus_type_and_status(handle, &type, &sta);
    if (result)
        return AE_OK;

    if (!(sta & ACPI_STA_DEVICE_PRESENT) &&
        !(sta & ACPI_STA_DEVICE_FUNCTIONING)) {
        struct acpi_device_wakeup wakeup;
        acpi_handle temp;

        status = acpi_get_handle(handle, "_PRW", &temp);
        if (ACPI_SUCCESS(status))
            acpi_bus_extract_wakeup_device_power_package(handle,
                                     &wakeup);
        return AE_CTRL_DEPTH;
    }

    /*
     * We may already have an acpi_device from a previous enumeration.  If
     * so, we needn't add it again, but we may still have to start it.
     */
    device = NULL;
    acpi_bus_get_device(handle, &device);
    if (ops->acpi_op_add && !device)
        acpi_add_single_object(&device, handle, type, sta, ops);

    if (!device)
        return AE_CTRL_DEPTH;

    if (ops->acpi_op_start && !(ops->acpi_op_add)) {
        status = acpi_start_single_object(device);
        if (ACPI_FAILURE(status))
            return AE_CTRL_DEPTH;
    }

    if (!*return_value)
        *return_value = device;
    return AE_OK;
}

static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops,
             struct acpi_device **child)
{
    acpi_status status;
    void *device = NULL;

    status = acpi_bus_check_add(handle, 0, ops, &device);
    if (ACPI_SUCCESS(status))
        acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
                    acpi_bus_check_add, NULL, ops, &device);

    if (child)
        *child = device;

    if (device)
        return 0;
    else
        return -ENODEV;
}

/*
 * acpi_bus_add and acpi_bus_start
 *
 * scan a given ACPI tree and (probably recently hot-plugged)
 * create and add or starts found devices.
 *
 * If no devices were found -ENODEV is returned which does not
 * mean that this is a real error, there just have been no suitable
 * ACPI objects in the table trunk from which the kernel could create
 * a device and add/start an appropriate driver.
 */

int
acpi_bus_add(struct acpi_device **child,
         struct acpi_device *parent, acpi_handle handle, int type)
{
    struct acpi_bus_ops ops;

    memset(&ops, 0, sizeof(ops));
    ops.acpi_op_add = 1;

    return acpi_bus_scan(handle, &ops, child);
}
EXPORT_SYMBOL(acpi_bus_add);

int acpi_bus_start(struct acpi_device *device)
{
    struct acpi_bus_ops ops;
    int result;

    if (!device)
        return -EINVAL;

    memset(&ops, 0, sizeof(ops));
    ops.acpi_op_start = 1;

    result = acpi_bus_scan(device->handle, &ops, NULL);

    acpi_update_all_gpes();

    return result;
}
EXPORT_SYMBOL(acpi_bus_start);

int acpi_bus_trim(struct acpi_device *start, int rmdevice)
{
    acpi_status status;
    struct acpi_device *parent, *child;
    acpi_handle phandle, chandle;
    acpi_object_type type;
    u32 level = 1;
    int err = 0;

    parent = start;
    phandle = start->handle;
    child = chandle = NULL;

    while ((level > 0) && parent && (!err)) {
        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);
            child = parent;
            parent = parent->parent;

            if (level == 0)
                err = acpi_bus_remove(child, rmdevice);
            else
                err = acpi_bus_remove(child, 1);

            continue;
        }

        status = acpi_get_type(chandle, &type);
        if (ACPI_FAILURE(status)) {
            continue;
        }
        /*
         * If there is a device corresponding to chandle then
         * parse it (depth-first).
         */
        if (acpi_bus_get_device(chandle, &child) == 0) {
            level++;
            phandle = chandle;
            chandle = NULL;
            parent = child;
        }
        continue;
    }
    return err;
}
EXPORT_SYMBOL_GPL(acpi_bus_trim);

static int acpi_bus_scan_fixed(void)
{
    int result = 0;
    struct acpi_device *device = NULL;
    struct acpi_bus_ops ops;

    memset(&ops, 0, sizeof(ops));
    ops.acpi_op_add = 1;
    ops.acpi_op_start = 1;

    /*
     * Enumerate all fixed-feature devices.
     */
    if ((acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON) == 0) {
        result = acpi_add_single_object(&device, NULL,
                        ACPI_BUS_TYPE_POWER_BUTTON,
                        ACPI_STA_DEFAULT,
                        &ops);
        device_init_wakeup(&device->dev, true);
    }

    if ((acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON) == 0) {
        result = acpi_add_single_object(&device, NULL,
                        ACPI_BUS_TYPE_SLEEP_BUTTON,
                        ACPI_STA_DEFAULT,
                        &ops);
    }

    return result;
}

int __init acpi_scan_init(void)
{
    int result;
    struct acpi_bus_ops ops;

    memset(&ops, 0, sizeof(ops));
    ops.acpi_op_add = 1;
    ops.acpi_op_start = 1;

    result = bus_register(&acpi_bus_type);
    if (result) {
        /* We don't want to quit even if we failed to add suspend/resume */
        printk(KERN_ERR PREFIX "Could not register bus type\n");
    }

    acpi_power_init();

    /*
     * Enumerate devices in the ACPI namespace.
     */
    result = acpi_bus_scan(ACPI_ROOT_OBJECT, &ops, &acpi_root);

    if (!result)
        result = acpi_bus_scan_fixed();

    if (result)
        acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL);
    else
        acpi_update_all_gpes();

    return result;
}