acer-wmi/hp-wmi: use platform_device_unregister instead of platform_device_del in...

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / platform / x86 / hp-wmi.c

/*
 * HP WMI hotkeys
 *
 * Copyright (C) 2008 Red Hat <mjg@redhat.com>
 *
 * Portions based on wistron_btns.c:
 * Copyright (C) 2005 Miloslav Trmac <mitr@volny.cz>
 * Copyright (C) 2005 Bernhard Rosenkraenzer <bero@arklinux.org>
 * Copyright (C) 2005 Dmitry Torokhov <dtor@mail.ru>
 *
 *  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/slab.h>
#include <linux/types.h>
#include <linux/input.h>
#include <acpi/acpi_drivers.h>
#include <linux/platform_device.h>
#include <linux/acpi.h>
#include <linux/rfkill.h>
#include <linux/string.h>

MODULE_AUTHOR("Matthew Garrett <mjg59@srcf.ucam.org>");
MODULE_DESCRIPTION("HP laptop WMI hotkeys driver");
MODULE_LICENSE("GPL");

MODULE_ALIAS("wmi:95F24279-4D7B-4334-9387-ACCDC67EF61C");
MODULE_ALIAS("wmi:5FB7F034-2C63-45e9-BE91-3D44E2C707E4");

#define HPWMI_EVENT_GUID "95F24279-4D7B-4334-9387-ACCDC67EF61C"
#define HPWMI_BIOS_GUID "5FB7F034-2C63-45e9-BE91-3D44E2C707E4"

#define HPWMI_DISPLAY_QUERY 0x1
#define HPWMI_HDDTEMP_QUERY 0x2
#define HPWMI_ALS_QUERY 0x3
#define HPWMI_HARDWARE_QUERY 0x4
#define HPWMI_WIRELESS_QUERY 0x5
#define HPWMI_HOTKEY_QUERY 0xc

#define PREFIX "HP WMI: "
#define UNIMP "Unimplemented "

enum hp_wmi_radio {
        HPWMI_WIFI = 0,
        HPWMI_BLUETOOTH = 1,
        HPWMI_WWAN = 2,
};

enum hp_wmi_event_ids {
        HPWMI_DOCK_EVENT = 1,
        HPWMI_PARK_HDD = 2,
        HPWMI_SMART_ADAPTER = 3,
        HPWMI_BEZEL_BUTTON = 4,
        HPWMI_WIRELESS = 5,
        HPWMI_CPU_BATTERY_THROTTLE = 6,
        HPWMI_LOCK_SWITCH = 7,
};

static int __devinit hp_wmi_bios_setup(struct platform_device *device);
static int __exit hp_wmi_bios_remove(struct platform_device *device);
static int hp_wmi_resume_handler(struct device *device);

struct bios_args {
        u32 signature;
        u32 command;
        u32 commandtype;
        u32 datasize;
        char *data;
};

struct bios_return {
        u32 sigpass;
        u32 return_code;
};

struct key_entry {
        char type;              /* See KE_* below */
        u16 code;
        u16 keycode;
};

enum { KE_KEY, KE_END };

static struct key_entry hp_wmi_keymap[] = {
        {KE_KEY, 0x02, KEY_BRIGHTNESSUP},
        {KE_KEY, 0x03, KEY_BRIGHTNESSDOWN},
        {KE_KEY, 0x20e6, KEY_PROG1},
        {KE_KEY, 0x20e8, KEY_MEDIA},
        {KE_KEY, 0x2142, KEY_MEDIA},
        {KE_KEY, 0x213b, KEY_INFO},
        {KE_KEY, 0x2169, KEY_DIRECTION},
        {KE_KEY, 0x231b, KEY_HELP},
        {KE_END, 0}
};

static struct input_dev *hp_wmi_input_dev;
static struct platform_device *hp_wmi_platform_dev;

static struct rfkill *wifi_rfkill;
static struct rfkill *bluetooth_rfkill;
static struct rfkill *wwan_rfkill;

static const struct dev_pm_ops hp_wmi_pm_ops = {
        .resume  = hp_wmi_resume_handler,
        .restore  = hp_wmi_resume_handler,
};

static struct platform_driver hp_wmi_driver = {
        .driver = {
                .name = "hp-wmi",
                .owner = THIS_MODULE,
                .pm = &hp_wmi_pm_ops,
        },
        .probe = hp_wmi_bios_setup,
        .remove = hp_wmi_bios_remove,
};

/*
 * hp_wmi_perform_query
 *
 * query:       The commandtype -> What should be queried
 * write:       The command -> 0 read, 1 write, 3 ODM specific
 * buffer:      Buffer used as input and/or output
 * buffersize:  Size of buffer
 *
 * returns zero on success
 *         an HP WMI query specific error code (which is positive)
 *         -EINVAL if the query was not successful at all
 *         -EINVAL if the output buffer size exceeds buffersize
 *
 * Note: The buffersize must at least be the maximum of the input and output
 *       size. E.g. Battery info query (0x7) is defined to have 1 byte input
 *       and 128 byte output. The caller would do:
 *       buffer = kzalloc(128, GFP_KERNEL);
 *       ret = hp_wmi_perform_query(0x7, 0, buffer, 128)
 */
static int hp_wmi_perform_query(int query, int write, char *buffer,
                                int buffersize)
{
        struct bios_return bios_return;
        acpi_status status;
        union acpi_object *obj;
        struct bios_args args = {
                .signature = 0x55434553,
                .command = write ? 0x2 : 0x1,
                .commandtype = query,
                .datasize = buffersize,
                .data = buffer,
        };
        struct acpi_buffer input = { sizeof(struct bios_args), &args };
        struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };

        status = wmi_evaluate_method(HPWMI_BIOS_GUID, 0, 0x3, &input, &output);

        obj = output.pointer;

        if (!obj)
                return -EINVAL;
        else if (obj->type != ACPI_TYPE_BUFFER) {
                kfree(obj);
                return -EINVAL;
        }

        bios_return = *((struct bios_return *)obj->buffer.pointer);

        if (bios_return.return_code) {
                printk(KERN_WARNING PREFIX "Query %d returned %d\n", query,
                       bios_return.return_code);
                kfree(obj);
                return bios_return.return_code;
        }
        if (obj->buffer.length - sizeof(bios_return) > buffersize) {
                kfree(obj);
                return -EINVAL;
        }

        memset(buffer, 0, buffersize);
        memcpy(buffer,
               ((char *)obj->buffer.pointer) + sizeof(struct bios_return),
               obj->buffer.length - sizeof(bios_return));
        kfree(obj);
        return 0;
}

static int hp_wmi_display_state(void)
{
        int state;
        int ret = hp_wmi_perform_query(HPWMI_DISPLAY_QUERY, 0, (char *)&state,
                                       sizeof(state));
        if (ret)
                return -EINVAL;
        return state;
}

static int hp_wmi_hddtemp_state(void)
{
        int state;
        int ret = hp_wmi_perform_query(HPWMI_HDDTEMP_QUERY, 0, (char *)&state,
                                       sizeof(state));
        if (ret)
                return -EINVAL;
        return state;
}

static int hp_wmi_als_state(void)
{
        int state;
        int ret = hp_wmi_perform_query(HPWMI_ALS_QUERY, 0, (char *)&state,
                                       sizeof(state));
        if (ret)
                return -EINVAL;
        return state;
}

static int hp_wmi_dock_state(void)
{
        int state;
        int ret = hp_wmi_perform_query(HPWMI_HARDWARE_QUERY, 0, (char *)&state,
                                       sizeof(state));

        if (ret)
                return -EINVAL;

        return state & 0x1;
}

static int hp_wmi_tablet_state(void)
{
        int state;
        int ret = hp_wmi_perform_query(HPWMI_HARDWARE_QUERY, 0, (char *)&state,
                                       sizeof(state));
        if (ret)
                return ret;

        return (state & 0x4) ? 1 : 0;
}

static int hp_wmi_set_block(void *data, bool blocked)
{
        enum hp_wmi_radio r = (enum hp_wmi_radio) data;
        int query = BIT(r + 8) | ((!blocked) << r);
        int ret;

        ret = hp_wmi_perform_query(HPWMI_WIRELESS_QUERY, 1,
                                   (char *)&query, sizeof(query));
        if (ret)
                return -EINVAL;
        return 0;
}

static const struct rfkill_ops hp_wmi_rfkill_ops = {
        .set_block = hp_wmi_set_block,
};

static bool hp_wmi_get_sw_state(enum hp_wmi_radio r)
{
        int wireless;
        int mask;
        hp_wmi_perform_query(HPWMI_WIRELESS_QUERY, 0,
                             (char *)&wireless, sizeof(wireless));
        /* TBD: Pass error */

        mask = 0x200 << (r * 8);

        if (wireless & mask)
                return false;
        else
                return true;
}

static bool hp_wmi_get_hw_state(enum hp_wmi_radio r)
{
        int wireless;
        int mask;
        hp_wmi_perform_query(HPWMI_WIRELESS_QUERY, 0,
                             (char *)&wireless, sizeof(wireless));
        /* TBD: Pass error */

        mask = 0x800 << (r * 8);

        if (wireless & mask)
                return false;
        else
                return true;
}

static ssize_t show_display(struct device *dev, struct device_attribute *attr,
                            char *buf)
{
        int value = hp_wmi_display_state();
        if (value < 0)
                return -EINVAL;
        return sprintf(buf, "%d\n", value);
}

static ssize_t show_hddtemp(struct device *dev, struct device_attribute *attr,
                            char *buf)
{
        int value = hp_wmi_hddtemp_state();
        if (value < 0)
                return -EINVAL;
        return sprintf(buf, "%d\n", value);
}

static ssize_t show_als(struct device *dev, struct device_attribute *attr,
                        char *buf)
{
        int value = hp_wmi_als_state();
        if (value < 0)
                return -EINVAL;
        return sprintf(buf, "%d\n", value);
}

static ssize_t show_dock(struct device *dev, struct device_attribute *attr,
                         char *buf)
{
        int value = hp_wmi_dock_state();
        if (value < 0)
                return -EINVAL;
        return sprintf(buf, "%d\n", value);
}

static ssize_t show_tablet(struct device *dev, struct device_attribute *attr,
                         char *buf)
{
        int value = hp_wmi_tablet_state();
        if (value < 0)
                return -EINVAL;
        return sprintf(buf, "%d\n", value);
}

static ssize_t set_als(struct device *dev, struct device_attribute *attr,
                       const char *buf, size_t count)
{
        u32 tmp = simple_strtoul(buf, NULL, 10);
        int ret = hp_wmi_perform_query(HPWMI_ALS_QUERY, 1, (char *)&tmp,
                                       sizeof(tmp));
        if (ret)
                return -EINVAL;

        return count;
}

static DEVICE_ATTR(display, S_IRUGO, show_display, NULL);
static DEVICE_ATTR(hddtemp, S_IRUGO, show_hddtemp, NULL);
static DEVICE_ATTR(als, S_IRUGO | S_IWUSR, show_als, set_als);
static DEVICE_ATTR(dock, S_IRUGO, show_dock, NULL);
static DEVICE_ATTR(tablet, S_IRUGO, show_tablet, NULL);

static struct key_entry *hp_wmi_get_entry_by_scancode(unsigned int code)
{
        struct key_entry *key;

        for (key = hp_wmi_keymap; key->type != KE_END; key++)
                if (code == key->code)
                        return key;

        return NULL;
}

static struct key_entry *hp_wmi_get_entry_by_keycode(unsigned int keycode)
{
        struct key_entry *key;

        for (key = hp_wmi_keymap; key->type != KE_END; key++)
                if (key->type == KE_KEY && keycode == key->keycode)
                        return key;

        return NULL;
}

static int hp_wmi_getkeycode(struct input_dev *dev,
                             unsigned int scancode, unsigned int *keycode)
{
        struct key_entry *key = hp_wmi_get_entry_by_scancode(scancode);

        if (key && key->type == KE_KEY) {
                *keycode = key->keycode;
                return 0;
        }

        return -EINVAL;
}

static int hp_wmi_setkeycode(struct input_dev *dev,
                             unsigned int scancode, unsigned int keycode)
{
        struct key_entry *key;
        unsigned int old_keycode;

        key = hp_wmi_get_entry_by_scancode(scancode);
        if (key && key->type == KE_KEY) {
                old_keycode = key->keycode;
                key->keycode = keycode;
                set_bit(keycode, dev->keybit);
                if (!hp_wmi_get_entry_by_keycode(old_keycode))
                        clear_bit(old_keycode, dev->keybit);
                return 0;
        }

        return -EINVAL;
}

static void hp_wmi_notify(u32 value, void *context)
{
        struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
        static struct key_entry *key;
        union acpi_object *obj;
        u32 event_id, event_data;
        int key_code, ret;
        u32 *location;
        acpi_status status;

        status = wmi_get_event_data(value, &response);
        if (status != AE_OK) {
                printk(KERN_INFO PREFIX "bad event status 0x%x\n", status);
                return;
        }

        obj = (union acpi_object *)response.pointer;

        if (obj || obj->type != ACPI_TYPE_BUFFER) {
                printk(KERN_INFO "hp-wmi: Unknown response received %d\n",
                       obj->type);
                kfree(obj);
                return;
        }

        /*
         * Depending on ACPI version the concatenation of id and event data
         * inside _WED function will result in a 8 or 16 byte buffer.
         */
        location = (u32 *)obj->buffer.pointer;
        if (obj->buffer.length == 8) {
                event_id = *location;
                event_data = *(location + 1);
        } else if (obj->buffer.length == 16) {
                event_id = *location;
                event_data = *(location + 2);
        } else {
                printk(KERN_INFO "hp-wmi: Unknown buffer length %d\n",
                       obj->buffer.length);
                kfree(obj);
                return;
        }
        kfree(obj);

        switch (event_id) {
        case HPWMI_DOCK_EVENT:
                input_report_switch(hp_wmi_input_dev, SW_DOCK,
                                    hp_wmi_dock_state());
                input_report_switch(hp_wmi_input_dev, SW_TABLET_MODE,
                                    hp_wmi_tablet_state());
                input_sync(hp_wmi_input_dev);
                break;
        case HPWMI_PARK_HDD:
                break;
        case HPWMI_SMART_ADAPTER:
                break;
        case HPWMI_BEZEL_BUTTON:
                ret = hp_wmi_perform_query(HPWMI_HOTKEY_QUERY, 0,
                                           (char *)&key_code,
                                           sizeof(key_code));
                if (ret)
                        break;
                key = hp_wmi_get_entry_by_scancode(key_code);
                if (key) {
                        switch (key->type) {
                        case KE_KEY:
                                input_report_key(hp_wmi_input_dev,
                                                 key->keycode, 1);
                                input_sync(hp_wmi_input_dev);
                                input_report_key(hp_wmi_input_dev,
                                                 key->keycode, 0);
                                input_sync(hp_wmi_input_dev);
                                break;
                        }
                } else
                        printk(KERN_INFO PREFIX "Unknown key code - 0x%x\n",
                               key_code);
                break;
        case HPWMI_WIRELESS:
                if (wifi_rfkill)
                        rfkill_set_states(wifi_rfkill,
                                          hp_wmi_get_sw_state(HPWMI_WIFI),
                                          hp_wmi_get_hw_state(HPWMI_WIFI));
                if (bluetooth_rfkill)
                        rfkill_set_states(bluetooth_rfkill,
                                          hp_wmi_get_sw_state(HPWMI_BLUETOOTH),
                                          hp_wmi_get_hw_state(HPWMI_BLUETOOTH));
                if (wwan_rfkill)
                        rfkill_set_states(wwan_rfkill,
                                          hp_wmi_get_sw_state(HPWMI_WWAN),
                                          hp_wmi_get_hw_state(HPWMI_WWAN));
                break;
        case HPWMI_CPU_BATTERY_THROTTLE:
                printk(KERN_INFO PREFIX UNIMP "CPU throttle because of 3 Cell"
                       " battery event detected\n");
                break;
        case HPWMI_LOCK_SWITCH:
                break;
        default:
                printk(KERN_INFO PREFIX "Unknown event_id - %d - 0x%x\n",
                       event_id, event_data);
                break;
        }
}

static int __init hp_wmi_input_setup(void)
{
        struct key_entry *key;
        int err;

        hp_wmi_input_dev = input_allocate_device();

        hp_wmi_input_dev->name = "HP WMI hotkeys";
        hp_wmi_input_dev->phys = "wmi/input0";
        hp_wmi_input_dev->id.bustype = BUS_HOST;
        hp_wmi_input_dev->getkeycode = hp_wmi_getkeycode;
        hp_wmi_input_dev->setkeycode = hp_wmi_setkeycode;

        for (key = hp_wmi_keymap; key->type != KE_END; key++) {
                switch (key->type) {
                case KE_KEY:
                        set_bit(EV_KEY, hp_wmi_input_dev->evbit);
                        set_bit(key->keycode, hp_wmi_input_dev->keybit);
                        break;
                }
        }

        set_bit(EV_SW, hp_wmi_input_dev->evbit);
        set_bit(SW_DOCK, hp_wmi_input_dev->swbit);
        set_bit(SW_TABLET_MODE, hp_wmi_input_dev->swbit);

        /* Set initial hardware state */
        input_report_switch(hp_wmi_input_dev, SW_DOCK, hp_wmi_dock_state());
        input_report_switch(hp_wmi_input_dev, SW_TABLET_MODE,
                            hp_wmi_tablet_state());
        input_sync(hp_wmi_input_dev);

        err = input_register_device(hp_wmi_input_dev);

        if (err) {
                input_free_device(hp_wmi_input_dev);
                return err;
        }

        return 0;
}

static void cleanup_sysfs(struct platform_device *device)
{
        device_remove_file(&device->dev, &dev_attr_display);
        device_remove_file(&device->dev, &dev_attr_hddtemp);
        device_remove_file(&device->dev, &dev_attr_als);
        device_remove_file(&device->dev, &dev_attr_dock);
        device_remove_file(&device->dev, &dev_attr_tablet);
}

static int __devinit hp_wmi_bios_setup(struct platform_device *device)
{
        int err;
        int wireless;

        err = hp_wmi_perform_query(HPWMI_WIRELESS_QUERY, 0, (char *)&wireless,
                                   sizeof(wireless));
        if (err)
                return err;

        err = device_create_file(&device->dev, &dev_attr_display);
        if (err)
                goto add_sysfs_error;
        err = device_create_file(&device->dev, &dev_attr_hddtemp);
        if (err)
                goto add_sysfs_error;
        err = device_create_file(&device->dev, &dev_attr_als);
        if (err)
                goto add_sysfs_error;
        err = device_create_file(&device->dev, &dev_attr_dock);
        if (err)
                goto add_sysfs_error;
        err = device_create_file(&device->dev, &dev_attr_tablet);
        if (err)
                goto add_sysfs_error;

        if (wireless & 0x1) {
                wifi_rfkill = rfkill_alloc("hp-wifi", &device->dev,
                                           RFKILL_TYPE_WLAN,
                                           &hp_wmi_rfkill_ops,
                                           (void *) HPWMI_WIFI);
                rfkill_init_sw_state(wifi_rfkill,
                                     hp_wmi_get_sw_state(HPWMI_WIFI));
                rfkill_set_hw_state(wifi_rfkill,
                                    hp_wmi_get_hw_state(HPWMI_WIFI));
                err = rfkill_register(wifi_rfkill);
                if (err)
                        goto register_wifi_error;
        }

        if (wireless & 0x2) {
                bluetooth_rfkill = rfkill_alloc("hp-bluetooth", &device->dev,
                                                RFKILL_TYPE_BLUETOOTH,
                                                &hp_wmi_rfkill_ops,
                                                (void *) HPWMI_BLUETOOTH);
                rfkill_init_sw_state(bluetooth_rfkill,
                                     hp_wmi_get_sw_state(HPWMI_BLUETOOTH));
                rfkill_set_hw_state(bluetooth_rfkill,
                                    hp_wmi_get_hw_state(HPWMI_BLUETOOTH));
                err = rfkill_register(bluetooth_rfkill);
                if (err)
                        goto register_bluetooth_error;
        }

        if (wireless & 0x4) {
                wwan_rfkill = rfkill_alloc("hp-wwan", &device->dev,
                                           RFKILL_TYPE_WWAN,
                                           &hp_wmi_rfkill_ops,
                                           (void *) HPWMI_WWAN);
                rfkill_init_sw_state(wwan_rfkill,
                                     hp_wmi_get_sw_state(HPWMI_WWAN));
                rfkill_set_hw_state(wwan_rfkill,
                                    hp_wmi_get_hw_state(HPWMI_WWAN));
                err = rfkill_register(wwan_rfkill);
                if (err)
                        goto register_wwan_err;
        }

        return 0;
register_wwan_err:
        rfkill_destroy(wwan_rfkill);
        if (bluetooth_rfkill)
                rfkill_unregister(bluetooth_rfkill);
register_bluetooth_error:
        rfkill_destroy(bluetooth_rfkill);
        if (wifi_rfkill)
                rfkill_unregister(wifi_rfkill);
register_wifi_error:
        rfkill_destroy(wifi_rfkill);
add_sysfs_error:
        cleanup_sysfs(device);
        return err;
}

static int __exit hp_wmi_bios_remove(struct platform_device *device)
{
        cleanup_sysfs(device);

        if (wifi_rfkill) {
                rfkill_unregister(wifi_rfkill);
                rfkill_destroy(wifi_rfkill);
        }
        if (bluetooth_rfkill) {
                rfkill_unregister(bluetooth_rfkill);
                rfkill_destroy(bluetooth_rfkill);
        }
        if (wwan_rfkill) {
                rfkill_unregister(wwan_rfkill);
                rfkill_destroy(wwan_rfkill);
        }

        return 0;
}

static int hp_wmi_resume_handler(struct device *device)
{
        /*
         * Hardware state may have changed while suspended, so trigger
         * input events for the current state. As this is a switch,
         * the input layer will only actually pass it on if the state
         * changed.
         */
        if (hp_wmi_input_dev) {
                input_report_switch(hp_wmi_input_dev, SW_DOCK,
                                    hp_wmi_dock_state());
                input_report_switch(hp_wmi_input_dev, SW_TABLET_MODE,
                                    hp_wmi_tablet_state());
                input_sync(hp_wmi_input_dev);
        }

        if (wifi_rfkill)
                rfkill_set_states(wifi_rfkill,
                                  hp_wmi_get_sw_state(HPWMI_WIFI),
                                  hp_wmi_get_hw_state(HPWMI_WIFI));
        if (bluetooth_rfkill)
                rfkill_set_states(bluetooth_rfkill,
                                  hp_wmi_get_sw_state(HPWMI_BLUETOOTH),
                                  hp_wmi_get_hw_state(HPWMI_BLUETOOTH));
        if (wwan_rfkill)
                rfkill_set_states(wwan_rfkill,
                                  hp_wmi_get_sw_state(HPWMI_WWAN),
                                  hp_wmi_get_hw_state(HPWMI_WWAN));

        return 0;
}

static int __init hp_wmi_init(void)
{
        int err;

        if (wmi_has_guid(HPWMI_EVENT_GUID)) {
                err = wmi_install_notify_handler(HPWMI_EVENT_GUID,
                                                 hp_wmi_notify, NULL);
                if (ACPI_FAILURE(err))
                        return -EINVAL;
                err = hp_wmi_input_setup();
                if (err) {
                        wmi_remove_notify_handler(HPWMI_EVENT_GUID);
                        return err;
                }
        }

        if (wmi_has_guid(HPWMI_BIOS_GUID)) {
                err = platform_driver_register(&hp_wmi_driver);
                if (err)
                        goto err_driver_reg;
                hp_wmi_platform_dev = platform_device_alloc("hp-wmi", -1);
                if (!hp_wmi_platform_dev) {
                        err = -ENOMEM;
                        goto err_device_alloc;
                }
                err = platform_device_add(hp_wmi_platform_dev);
                if (err)
                        goto err_device_add;
        }

        return 0;

err_device_add:
        platform_device_put(hp_wmi_platform_dev);
err_device_alloc:
        platform_driver_unregister(&hp_wmi_driver);
err_driver_reg:
        if (wmi_has_guid(HPWMI_EVENT_GUID)) {
                input_unregister_device(hp_wmi_input_dev);
                wmi_remove_notify_handler(HPWMI_EVENT_GUID);
        }

        return err;
}

static void __exit hp_wmi_exit(void)
{
        if (wmi_has_guid(HPWMI_EVENT_GUID)) {
                wmi_remove_notify_handler(HPWMI_EVENT_GUID);
                input_unregister_device(hp_wmi_input_dev);
        }
        if (hp_wmi_platform_dev) {
                platform_device_unregister(hp_wmi_platform_dev);
                platform_driver_unregister(&hp_wmi_driver);
        }
}

module_init(hp_wmi_init);
module_exit(hp_wmi_exit);