/*
 * Link physical devices with ACPI devices support
 *
 * Copyright (c) 2005 David Shaohua Li <shaohua.li@intel.com>
 * Copyright (c) 2005 Intel Corp.
 *
 * This file is released under the GPLv2.
 */
#include <linux/init.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/rwsem.h>
#include <linux/acpi.h>

#define ACPI_GLUE_DEBUG 0
#if ACPI_GLUE_DEBUG
#define DBG(x...) printk(PREFIX x)
#else
#define DBG(x...) do { } while(0)
#endif
static LIST_HEAD(bus_type_list);
static DECLARE_RWSEM(bus_type_sem);

int register_acpi_bus_type(struct acpi_bus_type *type)
{
        if (acpi_disabled)
                return -ENODEV;
        if (type && type->bus && type->find_device) {
                down_write(&bus_type_sem);
                list_add_tail(&type->list, &bus_type_list);
                up_write(&bus_type_sem);
                printk(KERN_INFO PREFIX "bus type %s registered\n",
                       type->bus->name);
                return 0;
        }
        return -ENODEV;
}

int unregister_acpi_bus_type(struct acpi_bus_type *type)
{
        if (acpi_disabled)
                return 0;
        if (type) {
                down_write(&bus_type_sem);
                list_del_init(&type->list);
                up_write(&bus_type_sem);
                printk(KERN_INFO PREFIX "ACPI bus type %s unregistered\n",
                       type->bus->name);
                return 0;
        }
        return -ENODEV;
}

static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type)
{
        struct acpi_bus_type *tmp, *ret = NULL;

        down_read(&bus_type_sem);
        list_for_each_entry(tmp, &bus_type_list, list) {
                if (tmp->bus == type) {
                        ret = tmp;
                        break;
                }
        }
        up_read(&bus_type_sem);
        return ret;
}

static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle)
{
        struct acpi_bus_type *tmp;
        int ret = -ENODEV;

        down_read(&bus_type_sem);
        list_for_each_entry(tmp, &bus_type_list, list) {
                if (tmp->find_bridge && !tmp->find_bridge(dev, handle)) {
                        ret = 0;
                        break;
                }
        }
        up_read(&bus_type_sem);
        return ret;
}

/* Get device's handler per its address under its parent */
struct acpi_find_child {
        acpi_handle handle;
        acpi_integer address;
};

static acpi_status
do_acpi_find_child(acpi_handle handle, u32 lvl, void *context, void **rv)
{
        acpi_status status;
        struct acpi_device_info *info;
        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
        struct acpi_find_child *find = context;

        status = acpi_get_object_info(handle, &buffer);
        if (ACPI_SUCCESS(status)) {
                info = buffer.pointer;
                if (info->address == find->address)
                        find->handle = handle;
                kfree(buffer.pointer);
        }
        return AE_OK;
}

acpi_handle acpi_get_child(acpi_handle parent, acpi_integer address)
{
        struct acpi_find_child find = { NULL, address };

        if (!parent)
                return NULL;
        acpi_walk_namespace(ACPI_TYPE_DEVICE, parent,
                            1, do_acpi_find_child, &find, NULL);
        return find.handle;
}

EXPORT_SYMBOL(acpi_get_child);

/* Link ACPI devices with physical devices */
static void acpi_glue_data_handler(acpi_handle handle,
                                   u32 function, void *context)
{
        /* we provide an empty handler */
}

/* Note: a success call will increase reference count by one */
struct device *acpi_get_physical_device(acpi_handle handle)
{
        acpi_status status;
        struct device *dev;

        status = acpi_get_data(handle, acpi_glue_data_handler, (void **)&dev);
        if (ACPI_SUCCESS(status))
                return get_device(dev);
        return NULL;
}

EXPORT_SYMBOL(acpi_get_physical_device);

/* ToDo: When a PCI bridge is found, return the PCI device behind the bridge
 *       This should work in general, but did not on a Lenovo T61 for the
 *       graphics card. But this must be fixed when the PCI device is
 *       bound and the kernel device struct is attached to the acpi device
 * Note: A success call will increase reference count by one
 *       Do call put_device(dev) on the returned device then
 */
struct device *acpi_get_physical_pci_device(acpi_handle handle)
{
        struct device *dev;
        long long device_id;
        acpi_status status;

        status =
                acpi_evaluate_integer(handle, "_ADR", NULL, &device_id);

        if (ACPI_FAILURE(status))
                return NULL;

        /* We need to attempt to determine whether the _ADR refers to a
           PCI device or not. There's no terribly good way to do this,
           so the best we can hope for is to assume that there'll never
           be a device in the host bridge */
        if (device_id >= 0x10000) {
                /* It looks like a PCI device. Does it exist? */
                dev = acpi_get_physical_device(handle);
        } else {
                /* It doesn't look like a PCI device. Does its parent
                   exist? */
                acpi_handle phandle;
                if (acpi_get_parent(handle, &phandle))
                        return NULL;
                dev = acpi_get_physical_device(phandle);
        }
        if (!dev)
                return NULL;
        return dev;
}
EXPORT_SYMBOL(acpi_get_physical_pci_device);

static int acpi_bind_one(struct device *dev, acpi_handle handle)
{
        struct acpi_device *acpi_dev;
        acpi_status status;

        if (dev->archdata.acpi_handle) {
                dev_warn(dev, "Drivers changed 'acpi_handle'\n");
                return -EINVAL;
        }
        get_device(dev);
        status = acpi_attach_data(handle, acpi_glue_data_handler, dev);
        if (ACPI_FAILURE(status)) {
                put_device(dev);
                return -EINVAL;
        }
        dev->archdata.acpi_handle = handle;

        status = acpi_bus_get_device(handle, &acpi_dev);
        if (!ACPI_FAILURE(status)) {
                int ret;

                ret = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
                                "firmware_node");
                ret = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
                                "physical_node");
                if (acpi_dev->wakeup.flags.valid) {
                        device_set_wakeup_capable(dev, true);
                        device_set_wakeup_enable(dev,
                                                acpi_dev->wakeup.state.enabled);
                }
        }

        return 0;
}

static int acpi_unbind_one(struct device *dev)
{
        if (!dev->archdata.acpi_handle)
                return 0;
        if (dev == acpi_get_physical_device(dev->archdata.acpi_handle)) {
                struct acpi_device *acpi_dev;

                /* acpi_get_physical_device increase refcnt by one */
                put_device(dev);

                if (!acpi_bus_get_device(dev->archdata.acpi_handle,
                                        &acpi_dev)) {
                        sysfs_remove_link(&dev->kobj, "firmware_node");
                        sysfs_remove_link(&acpi_dev->dev.kobj, "physical_node");
                }

                acpi_detach_data(dev->archdata.acpi_handle,
                                 acpi_glue_data_handler);
                dev->archdata.acpi_handle = NULL;
                /* acpi_bind_one increase refcnt by one */
                put_device(dev);
        } else {
                dev_err(dev, "Oops, 'acpi_handle' corrupt\n");
        }
        return 0;
}

static int acpi_platform_notify(struct device *dev)
{
        struct acpi_bus_type *type;
        acpi_handle handle;
        int ret = -EINVAL;

        if (!dev->bus || !dev->parent) {
                /* bridge devices genernally haven't bus or parent */
                ret = acpi_find_bridge_device(dev, &handle);
                goto end;
        }
        type = acpi_get_bus_type(dev->bus);
        if (!type) {
                DBG("No ACPI bus support for %s\n", dev_name(dev));
                ret = -EINVAL;
                goto end;
        }
        if ((ret = type->find_device(dev, &handle)) != 0)
                DBG("Can't get handler for %s\n", dev_name(dev));
      end:
        if (!ret)
                acpi_bind_one(dev, handle);

#if ACPI_GLUE_DEBUG
        if (!ret) {
                struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

                acpi_get_name(dev->archdata.acpi_handle,
                              ACPI_FULL_PATHNAME, &buffer);
                DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
                kfree(buffer.pointer);
        } else
                DBG("Device %s -> No ACPI support\n", dev_name(dev));
#endif

        return ret;
}

static int acpi_platform_notify_remove(struct device *dev)
{
        acpi_unbind_one(dev);
        return 0;
}

int __init init_acpi_device_notify(void)
{
        if (platform_notify || platform_notify_remove) {
                printk(KERN_ERR PREFIX "Can't use platform_notify\n");
                return 0;
        }
        platform_notify = acpi_platform_notify;
        platform_notify_remove = acpi_platform_notify_remove;
        return 0;
}