Merge tag 'linux-kselftest-4.10-rc4-fixes' of git://git.kernel.org/pub/scm/linux...

[mirror_ubuntu-bionic-kernel.git] / drivers / hid / wacom_sys.c

/*
 * drivers/input/tablet/wacom_sys.c
 *
 *  USB Wacom tablet support - system specific code
 */

/*
 * 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.
 */

#include "wacom_wac.h"
#include "wacom.h"
#include <linux/input/mt.h>

#define WAC_MSG_RETRIES         5

#define WAC_CMD_WL_LED_CONTROL  0x03
#define WAC_CMD_LED_CONTROL     0x20
#define WAC_CMD_ICON_START      0x21
#define WAC_CMD_ICON_XFER       0x23
#define WAC_CMD_ICON_BT_XFER    0x26
#define WAC_CMD_RETRIES         10
#define WAC_CMD_DELETE_PAIRING  0x20
#define WAC_CMD_UNPAIR_ALL      0xFF

#define DEV_ATTR_RW_PERM (S_IRUGO | S_IWUSR | S_IWGRP)
#define DEV_ATTR_WO_PERM (S_IWUSR | S_IWGRP)
#define DEV_ATTR_RO_PERM (S_IRUSR | S_IRGRP)

static int wacom_get_report(struct hid_device *hdev, u8 type, u8 *buf,
                            size_t size, unsigned int retries)
{
        int retval;

        do {
                retval = hid_hw_raw_request(hdev, buf[0], buf, size, type,
                                HID_REQ_GET_REPORT);
        } while ((retval == -ETIMEDOUT || retval == -EAGAIN) && --retries);

        if (retval < 0)
                hid_err(hdev, "wacom_get_report: ran out of retries "
                        "(last error = %d)\n", retval);

        return retval;
}

static int wacom_set_report(struct hid_device *hdev, u8 type, u8 *buf,
                            size_t size, unsigned int retries)
{
        int retval;

        do {
                retval = hid_hw_raw_request(hdev, buf[0], buf, size, type,
                                HID_REQ_SET_REPORT);
        } while ((retval == -ETIMEDOUT || retval == -EAGAIN) && --retries);

        if (retval < 0)
                hid_err(hdev, "wacom_set_report: ran out of retries "
                        "(last error = %d)\n", retval);

        return retval;
}

static int wacom_raw_event(struct hid_device *hdev, struct hid_report *report,
                u8 *raw_data, int size)
{
        struct wacom *wacom = hid_get_drvdata(hdev);

        if (size > WACOM_PKGLEN_MAX)
                return 1;

        memcpy(wacom->wacom_wac.data, raw_data, size);

        wacom_wac_irq(&wacom->wacom_wac, size);

        return 0;
}

static int wacom_open(struct input_dev *dev)
{
        struct wacom *wacom = input_get_drvdata(dev);

        return hid_hw_open(wacom->hdev);
}

static void wacom_close(struct input_dev *dev)
{
        struct wacom *wacom = input_get_drvdata(dev);

        /*
         * wacom->hdev should never be null, but surprisingly, I had the case
         * once while unplugging the Wacom Wireless Receiver.
         */
        if (wacom->hdev)
                hid_hw_close(wacom->hdev);
}

/*
 * Calculate the resolution of the X or Y axis using hidinput_calc_abs_res.
 */
static int wacom_calc_hid_res(int logical_extents, int physical_extents,
                               unsigned unit, int exponent)
{
        struct hid_field field = {
                .logical_maximum = logical_extents,
                .physical_maximum = physical_extents,
                .unit = unit,
                .unit_exponent = exponent,
        };

        return hidinput_calc_abs_res(&field, ABS_X);
}

static void wacom_feature_mapping(struct hid_device *hdev,
                struct hid_field *field, struct hid_usage *usage)
{
        struct wacom *wacom = hid_get_drvdata(hdev);
        struct wacom_features *features = &wacom->wacom_wac.features;
        struct hid_data *hid_data = &wacom->wacom_wac.hid_data;
        u8 *data;
        int ret;
        int n;

        switch (usage->hid) {
        case HID_DG_CONTACTMAX:
                /* leave touch_max as is if predefined */
                if (!features->touch_max) {
                        /* read manually */
                        data = kzalloc(2, GFP_KERNEL);
                        if (!data)
                                break;
                        data[0] = field->report->id;
                        ret = wacom_get_report(hdev, HID_FEATURE_REPORT,
                                                data, 2, WAC_CMD_RETRIES);
                        if (ret == 2) {
                                features->touch_max = data[1];
                        } else {
                                features->touch_max = 16;
                                hid_warn(hdev, "wacom_feature_mapping: "
                                         "could not get HID_DG_CONTACTMAX, "
                                         "defaulting to %d\n",
                                          features->touch_max);
                        }
                        kfree(data);
                }
                break;
        case HID_DG_INPUTMODE:
                /* Ignore if value index is out of bounds. */
                if (usage->usage_index >= field->report_count) {
                        dev_err(&hdev->dev, "HID_DG_INPUTMODE out of range\n");
                        break;
                }

                hid_data->inputmode = field->report->id;
                hid_data->inputmode_index = usage->usage_index;
                break;

        case HID_UP_DIGITIZER:
                if (field->report->id == 0x0B &&
                    (field->application == WACOM_HID_G9_PEN ||
                     field->application == WACOM_HID_G11_PEN)) {
                        wacom->wacom_wac.mode_report = field->report->id;
                        wacom->wacom_wac.mode_value = 0;
                }
                break;

        case WACOM_HID_WD_DATAMODE:
                wacom->wacom_wac.mode_report = field->report->id;
                wacom->wacom_wac.mode_value = 2;
                break;

        case WACOM_HID_UP_G9:
        case WACOM_HID_UP_G11:
                if (field->report->id == 0x03 &&
                    (field->application == WACOM_HID_G9_TOUCHSCREEN ||
                     field->application == WACOM_HID_G11_TOUCHSCREEN)) {
                        wacom->wacom_wac.mode_report = field->report->id;
                        wacom->wacom_wac.mode_value = 0;
                }
                break;
        case WACOM_HID_WD_OFFSETLEFT:
        case WACOM_HID_WD_OFFSETTOP:
        case WACOM_HID_WD_OFFSETRIGHT:
        case WACOM_HID_WD_OFFSETBOTTOM:
                /* read manually */
                n = hid_report_len(field->report);
                data = hid_alloc_report_buf(field->report, GFP_KERNEL);
                if (!data)
                        break;
                data[0] = field->report->id;
                ret = wacom_get_report(hdev, HID_FEATURE_REPORT,
                                        data, n, WAC_CMD_RETRIES);
                if (ret == n) {
                        ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT,
                                                   data, n, 0);
                } else {
                        hid_warn(hdev, "%s: could not retrieve sensor offsets\n",
                                 __func__);
                }
                kfree(data);
                break;
        }
}

/*
 * Interface Descriptor of wacom devices can be incomplete and
 * inconsistent so wacom_features table is used to store stylus
 * device's packet lengths, various maximum values, and tablet
 * resolution based on product ID's.
 *
 * For devices that contain 2 interfaces, wacom_features table is
 * inaccurate for the touch interface.  Since the Interface Descriptor
 * for touch interfaces has pretty complete data, this function exists
 * to query tablet for this missing information instead of hard coding in
 * an additional table.
 *
 * A typical Interface Descriptor for a stylus will contain a
 * boot mouse application collection that is not of interest and this
 * function will ignore it.
 *
 * It also contains a digitizer application collection that also is not
 * of interest since any information it contains would be duplicate
 * of what is in wacom_features. Usually it defines a report of an array
 * of bytes that could be used as max length of the stylus packet returned.
 * If it happens to define a Digitizer-Stylus Physical Collection then
 * the X and Y logical values contain valid data but it is ignored.
 *
 * A typical Interface Descriptor for a touch interface will contain a
 * Digitizer-Finger Physical Collection which will define both logical
 * X/Y maximum as well as the physical size of tablet. Since touch
 * interfaces haven't supported pressure or distance, this is enough
 * information to override invalid values in the wacom_features table.
 *
 * Intuos5 touch interface and 3rd gen Bamboo Touch do not contain useful
 * data. We deal with them after returning from this function.
 */
static void wacom_usage_mapping(struct hid_device *hdev,
                struct hid_field *field, struct hid_usage *usage)
{
        struct wacom *wacom = hid_get_drvdata(hdev);
        struct wacom_features *features = &wacom->wacom_wac.features;
        bool finger = WACOM_FINGER_FIELD(field);
        bool pen = WACOM_PEN_FIELD(field);

        /*
        * Requiring Stylus Usage will ignore boot mouse
        * X/Y values and some cases of invalid Digitizer X/Y
        * values commonly reported.
        */
        if (pen)
                features->device_type |= WACOM_DEVICETYPE_PEN;
        else if (finger)
                features->device_type |= WACOM_DEVICETYPE_TOUCH;
        else
                return;

        /*
         * Bamboo models do not support HID_DG_CONTACTMAX.
         * And, Bamboo Pen only descriptor contains touch.
         */
        if (features->type > BAMBOO_PT) {
                /* ISDv4 touch devices at least supports one touch point */
                if (finger && !features->touch_max)
                        features->touch_max = 1;
        }

        /*
         * ISDv4 devices which predate HID's adoption of the
         * HID_DG_BARELSWITCH2 usage use 0x000D0000 in its
         * position instead. We can accurately detect if a
         * usage with that value should be HID_DG_BARRELSWITCH2
         * based on the surrounding usages, which have remained
         * constant across generations.
         */
        if (features->type == HID_GENERIC &&
            usage->hid == 0x000D0000 &&
            field->application == HID_DG_PEN &&
            field->physical == HID_DG_STYLUS) {
                int i = usage->usage_index;

                if (i-4 >= 0 && i+1 < field->maxusage &&
                    field->usage[i-4].hid == HID_DG_TIPSWITCH &&
                    field->usage[i-3].hid == HID_DG_BARRELSWITCH &&
                    field->usage[i-2].hid == HID_DG_ERASER &&
                    field->usage[i-1].hid == HID_DG_INVERT &&
                    field->usage[i+1].hid == HID_DG_INRANGE) {
                        usage->hid = HID_DG_BARRELSWITCH2;
                }
        }

        switch (usage->hid) {
        case HID_GD_X:
                features->x_max = field->logical_maximum;
                if (finger) {
                        features->x_phy = field->physical_maximum;
                        if ((features->type != BAMBOO_PT) &&
                            (features->type != BAMBOO_TOUCH)) {
                                features->unit = field->unit;
                                features->unitExpo = field->unit_exponent;
                        }
                }
                break;
        case HID_GD_Y:
                features->y_max = field->logical_maximum;
                if (finger) {
                        features->y_phy = field->physical_maximum;
                        if ((features->type != BAMBOO_PT) &&
                            (features->type != BAMBOO_TOUCH)) {
                                features->unit = field->unit;
                                features->unitExpo = field->unit_exponent;
                        }
                }
                break;
        case HID_DG_TIPPRESSURE:
                if (pen)
                        features->pressure_max = field->logical_maximum;
                break;
        }

        if (features->type == HID_GENERIC)
                wacom_wac_usage_mapping(hdev, field, usage);
}

static void wacom_post_parse_hid(struct hid_device *hdev,
                                 struct wacom_features *features)
{
        struct wacom *wacom = hid_get_drvdata(hdev);
        struct wacom_wac *wacom_wac = &wacom->wacom_wac;

        if (features->type == HID_GENERIC) {
                /* Any last-minute generic device setup */
                if (features->touch_max > 1) {
                        input_mt_init_slots(wacom_wac->touch_input, wacom_wac->features.touch_max,
                                    INPUT_MT_DIRECT);
                }
        }
}

static void wacom_parse_hid(struct hid_device *hdev,
                           struct wacom_features *features)
{
        struct hid_report_enum *rep_enum;
        struct hid_report *hreport;
        int i, j;

        /* check features first */
        rep_enum = &hdev->report_enum[HID_FEATURE_REPORT];
        list_for_each_entry(hreport, &rep_enum->report_list, list) {
                for (i = 0; i < hreport->maxfield; i++) {
                        /* Ignore if report count is out of bounds. */
                        if (hreport->field[i]->report_count < 1)
                                continue;

                        for (j = 0; j < hreport->field[i]->maxusage; j++) {
                                wacom_feature_mapping(hdev, hreport->field[i],
                                                hreport->field[i]->usage + j);
                        }
                }
        }

        /* now check the input usages */
        rep_enum = &hdev->report_enum[HID_INPUT_REPORT];
        list_for_each_entry(hreport, &rep_enum->report_list, list) {

                if (!hreport->maxfield)
                        continue;

                for (i = 0; i < hreport->maxfield; i++)
                        for (j = 0; j < hreport->field[i]->maxusage; j++)
                                wacom_usage_mapping(hdev, hreport->field[i],
                                                hreport->field[i]->usage + j);
        }

        wacom_post_parse_hid(hdev, features);
}

static int wacom_hid_set_device_mode(struct hid_device *hdev)
{
        struct wacom *wacom = hid_get_drvdata(hdev);
        struct hid_data *hid_data = &wacom->wacom_wac.hid_data;
        struct hid_report *r;
        struct hid_report_enum *re;

        if (hid_data->inputmode < 0)
                return 0;

        re = &(hdev->report_enum[HID_FEATURE_REPORT]);
        r = re->report_id_hash[hid_data->inputmode];
        if (r) {
                r->field[0]->value[hid_data->inputmode_index] = 2;
                hid_hw_request(hdev, r, HID_REQ_SET_REPORT);
        }
        return 0;
}

static int wacom_set_device_mode(struct hid_device *hdev,
                                 struct wacom_wac *wacom_wac)
{
        u8 *rep_data;
        struct hid_report *r;
        struct hid_report_enum *re;
        int length;
        int error = -ENOMEM, limit = 0;

        if (wacom_wac->mode_report < 0)
                return 0;

        re = &(hdev->report_enum[HID_FEATURE_REPORT]);
        r = re->report_id_hash[wacom_wac->mode_report];
        if (!r)
                return -EINVAL;

        rep_data = hid_alloc_report_buf(r, GFP_KERNEL);
        if (!rep_data)
                return -ENOMEM;

        length = hid_report_len(r);

        do {
                rep_data[0] = wacom_wac->mode_report;
                rep_data[1] = wacom_wac->mode_value;

                error = wacom_set_report(hdev, HID_FEATURE_REPORT, rep_data,
                                         length, 1);
                if (error >= 0)
                        error = wacom_get_report(hdev, HID_FEATURE_REPORT,
                                                 rep_data, length, 1);
        } while (error >= 0 &&
                 rep_data[1] != wacom_wac->mode_report &&
                 limit++ < WAC_MSG_RETRIES);

        kfree(rep_data);

        return error < 0 ? error : 0;
}

static int wacom_bt_query_tablet_data(struct hid_device *hdev, u8 speed,
                struct wacom_features *features)
{
        struct wacom *wacom = hid_get_drvdata(hdev);
        int ret;
        u8 rep_data[2];

        switch (features->type) {
        case GRAPHIRE_BT:
                rep_data[0] = 0x03;
                rep_data[1] = 0x00;
                ret = wacom_set_report(hdev, HID_FEATURE_REPORT, rep_data, 2,
                                        3);

                if (ret >= 0) {
                        rep_data[0] = speed == 0 ? 0x05 : 0x06;
                        rep_data[1] = 0x00;

                        ret = wacom_set_report(hdev, HID_FEATURE_REPORT,
                                                rep_data, 2, 3);

                        if (ret >= 0) {
                                wacom->wacom_wac.bt_high_speed = speed;
                                return 0;
                        }
                }

                /*
                 * Note that if the raw queries fail, it's not a hard failure
                 * and it is safe to continue
                 */
                hid_warn(hdev, "failed to poke device, command %d, err %d\n",
                         rep_data[0], ret);
                break;
        case INTUOS4WL:
                if (speed == 1)
                        wacom->wacom_wac.bt_features &= ~0x20;
                else
                        wacom->wacom_wac.bt_features |= 0x20;

                rep_data[0] = 0x03;
                rep_data[1] = wacom->wacom_wac.bt_features;

                ret = wacom_set_report(hdev, HID_FEATURE_REPORT, rep_data, 2,
                                        1);
                if (ret >= 0)
                        wacom->wacom_wac.bt_high_speed = speed;
                break;
        }

        return 0;
}

/*
 * Switch the tablet into its most-capable mode. Wacom tablets are
 * typically configured to power-up in a mode which sends mouse-like
 * reports to the OS. To get absolute position, pressure data, etc.
 * from the tablet, it is necessary to switch the tablet out of this
 * mode and into one which sends the full range of tablet data.
 */
static int wacom_query_tablet_data(struct hid_device *hdev,
                struct wacom_features *features)
{
        struct wacom *wacom = hid_get_drvdata(hdev);
        struct wacom_wac *wacom_wac = &wacom->wacom_wac;

        if (hdev->bus == BUS_BLUETOOTH)
                return wacom_bt_query_tablet_data(hdev, 1, features);

        if (features->type != HID_GENERIC) {
                if (features->device_type & WACOM_DEVICETYPE_TOUCH) {
                        if (features->type > TABLETPC) {
                                /* MT Tablet PC touch */
                                wacom_wac->mode_report = 3;
                                wacom_wac->mode_value = 4;
                        } else if (features->type == WACOM_24HDT) {
                                wacom_wac->mode_report = 18;
                                wacom_wac->mode_value = 2;
                        } else if (features->type == WACOM_27QHDT) {
                                wacom_wac->mode_report = 131;
                                wacom_wac->mode_value = 2;
                        } else if (features->type == BAMBOO_PAD) {
                                wacom_wac->mode_report = 2;
                                wacom_wac->mode_value = 2;
                        }
                } else if (features->device_type & WACOM_DEVICETYPE_PEN) {
                        if (features->type <= BAMBOO_PT) {
                                wacom_wac->mode_report = 2;
                                wacom_wac->mode_value = 2;
                        }
                }
        }

        wacom_set_device_mode(hdev, wacom_wac);

        if (features->type == HID_GENERIC)
                return wacom_hid_set_device_mode(hdev);

        return 0;
}

static void wacom_retrieve_hid_descriptor(struct hid_device *hdev,
                                         struct wacom_features *features)
{
        struct wacom *wacom = hid_get_drvdata(hdev);
        struct usb_interface *intf = wacom->intf;

        /* default features */
        features->x_fuzz = 4;
        features->y_fuzz = 4;
        features->pressure_fuzz = 0;
        features->distance_fuzz = 1;
        features->tilt_fuzz = 1;

        /*
         * The wireless device HID is basic and layout conflicts with
         * other tablets (monitor and touch interface can look like pen).
         * Skip the query for this type and modify defaults based on
         * interface number.
         */
        if (features->type == WIRELESS) {
                if (intf->cur_altsetting->desc.bInterfaceNumber == 0)
                        features->device_type = WACOM_DEVICETYPE_WL_MONITOR;
                else
                        features->device_type = WACOM_DEVICETYPE_NONE;
                return;
        }

        wacom_parse_hid(hdev, features);
}

struct wacom_hdev_data {
        struct list_head list;
        struct kref kref;
        struct hid_device *dev;
        struct wacom_shared shared;
};

static LIST_HEAD(wacom_udev_list);
static DEFINE_MUTEX(wacom_udev_list_lock);

static bool compare_device_paths(struct hid_device *hdev_a,
                struct hid_device *hdev_b, char separator)
{
        int n1 = strrchr(hdev_a->phys, separator) - hdev_a->phys;
        int n2 = strrchr(hdev_b->phys, separator) - hdev_b->phys;

        if (n1 != n2 || n1 <= 0 || n2 <= 0)
                return false;

        return !strncmp(hdev_a->phys, hdev_b->phys, n1);
}

static bool wacom_are_sibling(struct hid_device *hdev,
                struct hid_device *sibling)
{
        struct wacom *wacom = hid_get_drvdata(hdev);
        struct wacom_features *features = &wacom->wacom_wac.features;
        struct wacom *sibling_wacom = hid_get_drvdata(sibling);
        struct wacom_features *sibling_features = &sibling_wacom->wacom_wac.features;
        __u32 oVid = features->oVid ? features->oVid : hdev->vendor;
        __u32 oPid = features->oPid ? features->oPid : hdev->product;

        /* The defined oVid/oPid must match that of the sibling */
        if (features->oVid != HID_ANY_ID && sibling->vendor != oVid)
                return false;
        if (features->oPid != HID_ANY_ID && sibling->product != oPid)
                return false;

        /*
         * Devices with the same VID/PID must share the same physical
         * device path, while those with different VID/PID must share
         * the same physical parent device path.
         */
        if (hdev->vendor == sibling->vendor && hdev->product == sibling->product) {
                if (!compare_device_paths(hdev, sibling, '/'))
                        return false;
        } else {
                if (!compare_device_paths(hdev, sibling, '.'))
                        return false;
        }

        /* Skip the remaining heuristics unless you are a HID_GENERIC device */
        if (features->type != HID_GENERIC)
                return true;

        /*
         * Direct-input devices may not be siblings of indirect-input
         * devices.
         */
        if ((features->device_type & WACOM_DEVICETYPE_DIRECT) &&
            !(sibling_features->device_type & WACOM_DEVICETYPE_DIRECT))
                return false;

        /*
         * Indirect-input devices may not be siblings of direct-input
         * devices.
         */
        if (!(features->device_type & WACOM_DEVICETYPE_DIRECT) &&
            (sibling_features->device_type & WACOM_DEVICETYPE_DIRECT))
                return false;

        /* Pen devices may only be siblings of touch devices */
        if ((features->device_type & WACOM_DEVICETYPE_PEN) &&
            !(sibling_features->device_type & WACOM_DEVICETYPE_TOUCH))
                return false;

        /* Touch devices may only be siblings of pen devices */
        if ((features->device_type & WACOM_DEVICETYPE_TOUCH) &&
            !(sibling_features->device_type & WACOM_DEVICETYPE_PEN))
                return false;

        /*
         * No reason could be found for these two devices to NOT be
         * siblings, so there's a good chance they ARE siblings
         */
        return true;
}

static struct wacom_hdev_data *wacom_get_hdev_data(struct hid_device *hdev)
{
        struct wacom_hdev_data *data;

        /* Try to find an already-probed interface from the same device */
        list_for_each_entry(data, &wacom_udev_list, list) {
                if (compare_device_paths(hdev, data->dev, '/'))
                        return data;
        }

        /* Fallback to finding devices that appear to be "siblings" */
        list_for_each_entry(data, &wacom_udev_list, list) {
                if (wacom_are_sibling(hdev, data->dev)) {
                        kref_get(&data->kref);
                        return data;
                }
        }

        return NULL;
}

static void wacom_release_shared_data(struct kref *kref)
{
        struct wacom_hdev_data *data =
                container_of(kref, struct wacom_hdev_data, kref);

        mutex_lock(&wacom_udev_list_lock);
        list_del(&data->list);
        mutex_unlock(&wacom_udev_list_lock);

        kfree(data);
}

static void wacom_remove_shared_data(void *res)
{
        struct wacom *wacom = res;
        struct wacom_hdev_data *data;
        struct wacom_wac *wacom_wac = &wacom->wacom_wac;

        if (wacom_wac->shared) {
                data = container_of(wacom_wac->shared, struct wacom_hdev_data,
                                    shared);

                if (wacom_wac->shared->touch == wacom->hdev)
                        wacom_wac->shared->touch = NULL;
                else if (wacom_wac->shared->pen == wacom->hdev)
                        wacom_wac->shared->pen = NULL;

                kref_put(&data->kref, wacom_release_shared_data);
                wacom_wac->shared = NULL;
        }
}

static int wacom_add_shared_data(struct hid_device *hdev)
{
        struct wacom *wacom = hid_get_drvdata(hdev);
        struct wacom_wac *wacom_wac = &wacom->wacom_wac;
        struct wacom_hdev_data *data;
        int retval = 0;

        mutex_lock(&wacom_udev_list_lock);

        data = wacom_get_hdev_data(hdev);
        if (!data) {
                data = kzalloc(sizeof(struct wacom_hdev_data), GFP_KERNEL);
                if (!data) {
                        retval = -ENOMEM;
                        goto out;
                }

                kref_init(&data->kref);
                data->dev = hdev;
                list_add_tail(&data->list, &wacom_udev_list);
        }

        wacom_wac->shared = &data->shared;

        retval = devm_add_action(&hdev->dev, wacom_remove_shared_data, wacom);
        if (retval) {
                mutex_unlock(&wacom_udev_list_lock);
                wacom_remove_shared_data(wacom);
                return retval;
        }

out:
        mutex_unlock(&wacom_udev_list_lock);
        return retval;
}

static int wacom_led_control(struct wacom *wacom)
{
        unsigned char *buf;
        int retval;
        unsigned char report_id = WAC_CMD_LED_CONTROL;
        int buf_size = 9;

        if (!hid_get_drvdata(wacom->hdev))
                return -ENODEV;

        if (!wacom->led.groups)
                return -ENOTSUPP;

        if (wacom->wacom_wac.pid) { /* wireless connected */
                report_id = WAC_CMD_WL_LED_CONTROL;
                buf_size = 13;
        }
        buf = kzalloc(buf_size, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        if (wacom->wacom_wac.features.type >= INTUOS5S &&
            wacom->wacom_wac.features.type <= INTUOSPL) {
                /*
                 * Touch Ring and crop mark LED luminance may take on
                 * one of four values:
                 *    0 = Low; 1 = Medium; 2 = High; 3 = Off
                 */
                int ring_led = wacom->led.groups[0].select & 0x03;
                int ring_lum = (((wacom->led.llv & 0x60) >> 5) - 1) & 0x03;
                int crop_lum = 0;
                unsigned char led_bits = (crop_lum << 4) | (ring_lum << 2) | (ring_led);

                buf[0] = report_id;
                if (wacom->wacom_wac.pid) {
                        wacom_get_report(wacom->hdev, HID_FEATURE_REPORT,
                                         buf, buf_size, WAC_CMD_RETRIES);
                        buf[0] = report_id;
                        buf[4] = led_bits;
                } else
                        buf[1] = led_bits;
        }
        else {
                int led = wacom->led.groups[0].select | 0x4;

                if (wacom->wacom_wac.features.type == WACOM_21UX2 ||
                    wacom->wacom_wac.features.type == WACOM_24HD)
                        led |= (wacom->led.groups[1].select << 4) | 0x40;

                buf[0] = report_id;
                buf[1] = led;
                buf[2] = wacom->led.llv;
                buf[3] = wacom->led.hlv;
                buf[4] = wacom->led.img_lum;
        }

        retval = wacom_set_report(wacom->hdev, HID_FEATURE_REPORT, buf, buf_size,
                                  WAC_CMD_RETRIES);
        kfree(buf);

        return retval;
}

static int wacom_led_putimage(struct wacom *wacom, int button_id, u8 xfer_id,
                const unsigned len, const void *img)
{
        unsigned char *buf;
        int i, retval;
        const unsigned chunk_len = len / 4; /* 4 chunks are needed to be sent */

        buf = kzalloc(chunk_len + 3 , GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        /* Send 'start' command */
        buf[0] = WAC_CMD_ICON_START;
        buf[1] = 1;
        retval = wacom_set_report(wacom->hdev, HID_FEATURE_REPORT, buf, 2,
                                  WAC_CMD_RETRIES);
        if (retval < 0)
                goto out;

        buf[0] = xfer_id;
        buf[1] = button_id & 0x07;
        for (i = 0; i < 4; i++) {
                buf[2] = i;
                memcpy(buf + 3, img + i * chunk_len, chunk_len);

                retval = wacom_set_report(wacom->hdev, HID_FEATURE_REPORT,
                                          buf, chunk_len + 3, WAC_CMD_RETRIES);
                if (retval < 0)
                        break;
        }

        /* Send 'stop' */
        buf[0] = WAC_CMD_ICON_START;
        buf[1] = 0;
        wacom_set_report(wacom->hdev, HID_FEATURE_REPORT, buf, 2,
                         WAC_CMD_RETRIES);

out:
        kfree(buf);
        return retval;
}

static ssize_t wacom_led_select_store(struct device *dev, int set_id,
                                      const char *buf, size_t count)
{
        struct hid_device *hdev = to_hid_device(dev);
        struct wacom *wacom = hid_get_drvdata(hdev);
        unsigned int id;
        int err;

        err = kstrtouint(buf, 10, &id);
        if (err)
                return err;

        mutex_lock(&wacom->lock);

        wacom->led.groups[set_id].select = id & 0x3;
        err = wacom_led_control(wacom);

        mutex_unlock(&wacom->lock);

        return err < 0 ? err : count;
}

#define DEVICE_LED_SELECT_ATTR(SET_ID)                                  \
static ssize_t wacom_led##SET_ID##_select_store(struct device *dev,     \
        struct device_attribute *attr, const char *buf, size_t count)   \
{                                                                       \
        return wacom_led_select_store(dev, SET_ID, buf, count);         \
}                                                                       \
static ssize_t wacom_led##SET_ID##_select_show(struct device *dev,      \
        struct device_attribute *attr, char *buf)                       \
{                                                                       \
        struct hid_device *hdev = to_hid_device(dev);\
        struct wacom *wacom = hid_get_drvdata(hdev);                    \
        return scnprintf(buf, PAGE_SIZE, "%d\n",                        \
                         wacom->led.groups[SET_ID].select);             \
}                                                                       \
static DEVICE_ATTR(status_led##SET_ID##_select, DEV_ATTR_RW_PERM,       \
                    wacom_led##SET_ID##_select_show,                    \
                    wacom_led##SET_ID##_select_store)

DEVICE_LED_SELECT_ATTR(0);
DEVICE_LED_SELECT_ATTR(1);

static ssize_t wacom_luminance_store(struct wacom *wacom, u8 *dest,
                                     const char *buf, size_t count)
{
        unsigned int value;
        int err;

        err = kstrtouint(buf, 10, &value);
        if (err)
                return err;

        mutex_lock(&wacom->lock);

        *dest = value & 0x7f;
        err = wacom_led_control(wacom);

        mutex_unlock(&wacom->lock);

        return err < 0 ? err : count;
}

#define DEVICE_LUMINANCE_ATTR(name, field)                              \
static ssize_t wacom_##name##_luminance_store(struct device *dev,       \
        struct device_attribute *attr, const char *buf, size_t count)   \
{                                                                       \
        struct hid_device *hdev = to_hid_device(dev);\
        struct wacom *wacom = hid_get_drvdata(hdev);                    \
                                                                        \
        return wacom_luminance_store(wacom, &wacom->led.field,          \
                                     buf, count);                       \
}                                                                       \
static ssize_t wacom_##name##_luminance_show(struct device *dev,        \
        struct device_attribute *attr, char *buf)                       \
{                                                                       \
        struct wacom *wacom = dev_get_drvdata(dev);                     \
        return scnprintf(buf, PAGE_SIZE, "%d\n", wacom->led.field);     \
}                                                                       \
static DEVICE_ATTR(name##_luminance, DEV_ATTR_RW_PERM,                  \
                   wacom_##name##_luminance_show,                       \
                   wacom_##name##_luminance_store)

DEVICE_LUMINANCE_ATTR(status0, llv);
DEVICE_LUMINANCE_ATTR(status1, hlv);
DEVICE_LUMINANCE_ATTR(buttons, img_lum);

static ssize_t wacom_button_image_store(struct device *dev, int button_id,
                                        const char *buf, size_t count)
{
        struct hid_device *hdev = to_hid_device(dev);
        struct wacom *wacom = hid_get_drvdata(hdev);
        int err;
        unsigned len;
        u8 xfer_id;

        if (hdev->bus == BUS_BLUETOOTH) {
                len = 256;
                xfer_id = WAC_CMD_ICON_BT_XFER;
        } else {
                len = 1024;
                xfer_id = WAC_CMD_ICON_XFER;
        }

        if (count != len)
                return -EINVAL;

        mutex_lock(&wacom->lock);

        err = wacom_led_putimage(wacom, button_id, xfer_id, len, buf);

        mutex_unlock(&wacom->lock);

        return err < 0 ? err : count;
}

#define DEVICE_BTNIMG_ATTR(BUTTON_ID)                                   \
static ssize_t wacom_btnimg##BUTTON_ID##_store(struct device *dev,      \
        struct device_attribute *attr, const char *buf, size_t count)   \
{                                                                       \
        return wacom_button_image_store(dev, BUTTON_ID, buf, count);    \
}                                                                       \
static DEVICE_ATTR(button##BUTTON_ID##_rawimg, DEV_ATTR_WO_PERM,        \
                   NULL, wacom_btnimg##BUTTON_ID##_store)

DEVICE_BTNIMG_ATTR(0);
DEVICE_BTNIMG_ATTR(1);
DEVICE_BTNIMG_ATTR(2);
DEVICE_BTNIMG_ATTR(3);
DEVICE_BTNIMG_ATTR(4);
DEVICE_BTNIMG_ATTR(5);
DEVICE_BTNIMG_ATTR(6);
DEVICE_BTNIMG_ATTR(7);

static struct attribute *cintiq_led_attrs[] = {
        &dev_attr_status_led0_select.attr,
        &dev_attr_status_led1_select.attr,
        NULL
};

static struct attribute_group cintiq_led_attr_group = {
        .name = "wacom_led",
        .attrs = cintiq_led_attrs,
};

static struct attribute *intuos4_led_attrs[] = {
        &dev_attr_status0_luminance.attr,
        &dev_attr_status1_luminance.attr,
        &dev_attr_status_led0_select.attr,
        &dev_attr_buttons_luminance.attr,
        &dev_attr_button0_rawimg.attr,
        &dev_attr_button1_rawimg.attr,
        &dev_attr_button2_rawimg.attr,
        &dev_attr_button3_rawimg.attr,
        &dev_attr_button4_rawimg.attr,
        &dev_attr_button5_rawimg.attr,
        &dev_attr_button6_rawimg.attr,
        &dev_attr_button7_rawimg.attr,
        NULL
};

static struct attribute_group intuos4_led_attr_group = {
        .name = "wacom_led",
        .attrs = intuos4_led_attrs,
};

static struct attribute *intuos5_led_attrs[] = {
        &dev_attr_status0_luminance.attr,
        &dev_attr_status_led0_select.attr,
        NULL
};

static struct attribute_group intuos5_led_attr_group = {
        .name = "wacom_led",
        .attrs = intuos5_led_attrs,
};

struct wacom_sysfs_group_devres {
        struct attribute_group *group;
        struct kobject *root;
};

static void wacom_devm_sysfs_group_release(struct device *dev, void *res)
{
        struct wacom_sysfs_group_devres *devres = res;
        struct kobject *kobj = devres->root;

        dev_dbg(dev, "%s: dropping reference to %s\n",
                __func__, devres->group->name);
        sysfs_remove_group(kobj, devres->group);
}

static int __wacom_devm_sysfs_create_group(struct wacom *wacom,
                                           struct kobject *root,
                                           struct attribute_group *group)
{
        struct wacom_sysfs_group_devres *devres;
        int error;

        devres = devres_alloc(wacom_devm_sysfs_group_release,
                              sizeof(struct wacom_sysfs_group_devres),
                              GFP_KERNEL);
        if (!devres)
                return -ENOMEM;

        devres->group = group;
        devres->root = root;

        error = sysfs_create_group(devres->root, group);
        if (error)
                return error;

        devres_add(&wacom->hdev->dev, devres);

        return 0;
}

static int wacom_devm_sysfs_create_group(struct wacom *wacom,
                                         struct attribute_group *group)
{
        return __wacom_devm_sysfs_create_group(wacom, &wacom->hdev->dev.kobj,
                                               group);
}

enum led_brightness wacom_leds_brightness_get(struct wacom_led *led)
{
        struct wacom *wacom = led->wacom;

        if (wacom->led.max_hlv)
                return led->hlv * LED_FULL / wacom->led.max_hlv;

        if (wacom->led.max_llv)
                return led->llv * LED_FULL / wacom->led.max_llv;

        /* device doesn't support brightness tuning */
        return LED_FULL;
}

static enum led_brightness __wacom_led_brightness_get(struct led_classdev *cdev)
{
        struct wacom_led *led = container_of(cdev, struct wacom_led, cdev);
        struct wacom *wacom = led->wacom;

        if (wacom->led.groups[led->group].select != led->id)
                return LED_OFF;

        return wacom_leds_brightness_get(led);
}

static int wacom_led_brightness_set(struct led_classdev *cdev,
                                    enum led_brightness brightness)
{
        struct wacom_led *led = container_of(cdev, struct wacom_led, cdev);
        struct wacom *wacom = led->wacom;
        int error;

        mutex_lock(&wacom->lock);

        if (!wacom->led.groups || (brightness == LED_OFF &&
            wacom->led.groups[led->group].select != led->id)) {
                error = 0;
                goto out;
        }

        led->llv = wacom->led.llv = wacom->led.max_llv * brightness / LED_FULL;
        led->hlv = wacom->led.hlv = wacom->led.max_hlv * brightness / LED_FULL;

        wacom->led.groups[led->group].select = led->id;

        error = wacom_led_control(wacom);

out:
        mutex_unlock(&wacom->lock);

        return error;
}

static void wacom_led_readonly_brightness_set(struct led_classdev *cdev,
                                               enum led_brightness brightness)
{
}

static int wacom_led_register_one(struct device *dev, struct wacom *wacom,
                                  struct wacom_led *led, unsigned int group,
                                  unsigned int id, bool read_only)
{
        int error;
        char *name;

        name = devm_kasprintf(dev, GFP_KERNEL,
                              "%s::wacom-%d.%d",
                              dev_name(dev),
                              group,
                              id);
        if (!name)
                return -ENOMEM;

        if (!read_only) {
                led->trigger.name = name;
                error = devm_led_trigger_register(dev, &led->trigger);
                if (error) {
                        hid_err(wacom->hdev,
                                "failed to register LED trigger %s: %d\n",
                                led->cdev.name, error);
                        return error;
                }
        }

        led->group = group;
        led->id = id;
        led->wacom = wacom;
        led->llv = wacom->led.llv;
        led->hlv = wacom->led.hlv;
        led->cdev.name = name;
        led->cdev.max_brightness = LED_FULL;
        led->cdev.flags = LED_HW_PLUGGABLE;
        led->cdev.brightness_get = __wacom_led_brightness_get;
        if (!read_only) {
                led->cdev.brightness_set_blocking = wacom_led_brightness_set;
                led->cdev.default_trigger = led->cdev.name;
        } else {
                led->cdev.brightness_set = wacom_led_readonly_brightness_set;
        }

        error = devm_led_classdev_register(dev, &led->cdev);
        if (error) {
                hid_err(wacom->hdev,
                        "failed to register LED %s: %d\n",
                        led->cdev.name, error);
                led->cdev.name = NULL;
                return error;
        }

        return 0;
}

static void wacom_led_groups_release_one(void *data)
{
        struct wacom_group_leds *group = data;

        devres_release_group(group->dev, group);
}

static int wacom_led_groups_alloc_and_register_one(struct device *dev,
                                                   struct wacom *wacom,
                                                   int group_id, int count,
                                                   bool read_only)
{
        struct wacom_led *leds;
        int i, error;

        if (group_id >= wacom->led.count || count <= 0)
                return -EINVAL;

        if (!devres_open_group(dev, &wacom->led.groups[group_id], GFP_KERNEL))
                return -ENOMEM;

        leds = devm_kzalloc(dev, sizeof(struct wacom_led) * count, GFP_KERNEL);
        if (!leds) {
                error = -ENOMEM;
                goto err;
        }

        wacom->led.groups[group_id].leds = leds;
        wacom->led.groups[group_id].count = count;

        for (i = 0; i < count; i++) {
                error = wacom_led_register_one(dev, wacom, &leds[i],
                                               group_id, i, read_only);
                if (error)
                        goto err;
        }

        wacom->led.groups[group_id].dev = dev;

        devres_close_group(dev, &wacom->led.groups[group_id]);

        /*
         * There is a bug (?) in devm_led_classdev_register() in which its
         * increments the refcount of the parent. If the parent is an input
         * device, that means the ref count never reaches 0 when
         * devm_input_device_release() gets called.
         * This means that the LEDs are still there after disconnect.
         * Manually force the release of the group so that the leds are released
         * once we are done using them.
         */
        error = devm_add_action_or_reset(&wacom->hdev->dev,
                                         wacom_led_groups_release_one,
                                         &wacom->led.groups[group_id]);
        if (error)
                return error;

        return 0;

err:
        devres_release_group(dev, &wacom->led.groups[group_id]);
        return error;
}

struct wacom_led *wacom_led_find(struct wacom *wacom, unsigned int group_id,
                                 unsigned int id)
{
        struct wacom_group_leds *group;

        if (group_id >= wacom->led.count)
                return NULL;

        group = &wacom->led.groups[group_id];

        if (!group->leds)
                return NULL;

        id %= group->count;

        return &group->leds[id];
}

/**
 * wacom_led_next: gives the next available led with a wacom trigger.
 *
 * returns the next available struct wacom_led which has its default trigger
 * or the current one if none is available.
 */
struct wacom_led *wacom_led_next(struct wacom *wacom, struct wacom_led *cur)
{
        struct wacom_led *next_led;
        int group, next;

        if (!wacom || !cur)
                return NULL;

        group = cur->group;
        next = cur->id;

        do {
                next_led = wacom_led_find(wacom, group, ++next);
                if (!next_led || next_led == cur)
                        return next_led;
        } while (next_led->cdev.trigger != &next_led->trigger);

        return next_led;
}

static void wacom_led_groups_release(void *data)
{
        struct wacom *wacom = data;

        wacom->led.groups = NULL;
        wacom->led.count = 0;
}

static int wacom_led_groups_allocate(struct wacom *wacom, int count)
{
        struct device *dev = &wacom->hdev->dev;
        struct wacom_group_leds *groups;
        int error;

        groups = devm_kzalloc(dev, sizeof(struct wacom_group_leds) * count,
                              GFP_KERNEL);
        if (!groups)
                return -ENOMEM;

        error = devm_add_action_or_reset(dev, wacom_led_groups_release, wacom);
        if (error)
                return error;

        wacom->led.groups = groups;
        wacom->led.count = count;

        return 0;
}

static int wacom_leds_alloc_and_register(struct wacom *wacom, int group_count,
                                         int led_per_group, bool read_only)
{
        struct device *dev;
        int i, error;

        if (!wacom->wacom_wac.pad_input)
                return -EINVAL;

        dev = &wacom->wacom_wac.pad_input->dev;

        error = wacom_led_groups_allocate(wacom, group_count);
        if (error)
                return error;

        for (i = 0; i < group_count; i++) {
                error = wacom_led_groups_alloc_and_register_one(dev, wacom, i,
                                                                led_per_group,
                                                                read_only);
                if (error)
                        return error;
        }

        return 0;
}

static int wacom_initialize_leds(struct wacom *wacom)
{
        int error;

        if (!(wacom->wacom_wac.features.device_type & WACOM_DEVICETYPE_PAD))
                return 0;

        /* Initialize default values */
        switch (wacom->wacom_wac.features.type) {
        case INTUOS4S:
        case INTUOS4:
        case INTUOS4WL:
        case INTUOS4L:
                wacom->led.llv = 10;
                wacom->led.hlv = 20;
                wacom->led.max_llv = 127;
                wacom->led.max_hlv = 127;
                wacom->led.img_lum = 10;

                error = wacom_leds_alloc_and_register(wacom, 1, 4, false);
                if (error) {
                        hid_err(wacom->hdev,
                                "cannot create leds err: %d\n", error);
                        return error;
                }

                error = wacom_devm_sysfs_create_group(wacom,
                                                      &intuos4_led_attr_group);
                break;

        case WACOM_24HD:
        case WACOM_21UX2:
                wacom->led.llv = 0;
                wacom->led.hlv = 0;
                wacom->led.img_lum = 0;

                error = wacom_leds_alloc_and_register(wacom, 2, 4, false);
                if (error) {
                        hid_err(wacom->hdev,
                                "cannot create leds err: %d\n", error);
                        return error;
                }

                error = wacom_devm_sysfs_create_group(wacom,
                                                      &cintiq_led_attr_group);
                break;

        case INTUOS5S:
        case INTUOS5:
        case INTUOS5L:
        case INTUOSPS:
        case INTUOSPM:
        case INTUOSPL:
                wacom->led.llv = 32;
                wacom->led.max_llv = 96;

                error = wacom_leds_alloc_and_register(wacom, 1, 4, false);
                if (error) {
                        hid_err(wacom->hdev,
                                "cannot create leds err: %d\n", error);
                        return error;
                }

                error = wacom_devm_sysfs_create_group(wacom,
                                                      &intuos5_led_attr_group);
                break;

        case REMOTE:
                wacom->led.llv = 255;
                wacom->led.max_llv = 255;
                error = wacom_led_groups_allocate(wacom, 5);
                if (error) {
                        hid_err(wacom->hdev,
                                "cannot create leds err: %d\n", error);
                        return error;
                }
                return 0;

        default:
                return 0;
        }

        if (error) {
                hid_err(wacom->hdev,
                        "cannot create sysfs group err: %d\n", error);
                return error;
        }
        wacom_led_control(wacom);

        return 0;
}

static enum power_supply_property wacom_battery_props[] = {
        POWER_SUPPLY_PROP_MODEL_NAME,
        POWER_SUPPLY_PROP_PRESENT,
        POWER_SUPPLY_PROP_STATUS,
        POWER_SUPPLY_PROP_SCOPE,
        POWER_SUPPLY_PROP_CAPACITY
};

static int wacom_battery_get_property(struct power_supply *psy,
                                      enum power_supply_property psp,
                                      union power_supply_propval *val)
{
        struct wacom_battery *battery = power_supply_get_drvdata(psy);
        int ret = 0;

        switch (psp) {
                case POWER_SUPPLY_PROP_MODEL_NAME:
                        val->strval = battery->wacom->wacom_wac.name;
                        break;
                case POWER_SUPPLY_PROP_PRESENT:
                        val->intval = battery->bat_connected;
                        break;
                case POWER_SUPPLY_PROP_SCOPE:
                        val->intval = POWER_SUPPLY_SCOPE_DEVICE;
                        break;
                case POWER_SUPPLY_PROP_CAPACITY:
                        val->intval = battery->battery_capacity;
                        break;
                case POWER_SUPPLY_PROP_STATUS:
                        if (battery->bat_charging)
                                val->intval = POWER_SUPPLY_STATUS_CHARGING;
                        else if (battery->battery_capacity == 100 &&
                                    battery->ps_connected)
                                val->intval = POWER_SUPPLY_STATUS_FULL;
                        else if (battery->ps_connected)
                                val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
                        else
                                val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
                        break;
                default:
                        ret = -EINVAL;
                        break;
        }

        return ret;
}

static int __wacom_initialize_battery(struct wacom *wacom,
                                      struct wacom_battery *battery)
{
        static atomic_t battery_no = ATOMIC_INIT(0);
        struct device *dev = &wacom->hdev->dev;
        struct power_supply_config psy_cfg = { .drv_data = battery, };
        struct power_supply *ps_bat;
        struct power_supply_desc *bat_desc = &battery->bat_desc;
        unsigned long n;
        int error;

        if (!devres_open_group(dev, bat_desc, GFP_KERNEL))
                return -ENOMEM;

        battery->wacom = wacom;

        n = atomic_inc_return(&battery_no) - 1;

        bat_desc->properties = wacom_battery_props;
        bat_desc->num_properties = ARRAY_SIZE(wacom_battery_props);
        bat_desc->get_property = wacom_battery_get_property;
        sprintf(battery->bat_name, "wacom_battery_%ld", n);
        bat_desc->name = battery->bat_name;
        bat_desc->type = POWER_SUPPLY_TYPE_USB;
        bat_desc->use_for_apm = 0;

        ps_bat = devm_power_supply_register(dev, bat_desc, &psy_cfg);
        if (IS_ERR(ps_bat)) {
                error = PTR_ERR(ps_bat);
                goto err;
        }

        power_supply_powers(ps_bat, &wacom->hdev->dev);

        battery->battery = ps_bat;

        devres_close_group(dev, bat_desc);
        return 0;

err:
        devres_release_group(dev, bat_desc);
        return error;
}

static int wacom_initialize_battery(struct wacom *wacom)
{
        if (wacom->wacom_wac.features.quirks & WACOM_QUIRK_BATTERY)
                return __wacom_initialize_battery(wacom, &wacom->battery);

        return 0;
}

static void wacom_destroy_battery(struct wacom *wacom)
{
        if (wacom->battery.battery) {
                devres_release_group(&wacom->hdev->dev,
                                     &wacom->battery.bat_desc);
                wacom->battery.battery = NULL;
        }
}

static ssize_t wacom_show_speed(struct device *dev,
                                struct device_attribute
                                *attr, char *buf)
{
        struct hid_device *hdev = to_hid_device(dev);
        struct wacom *wacom = hid_get_drvdata(hdev);

        return snprintf(buf, PAGE_SIZE, "%i\n", wacom->wacom_wac.bt_high_speed);
}

static ssize_t wacom_store_speed(struct device *dev,
                                struct device_attribute *attr,
                                const char *buf, size_t count)
{
        struct hid_device *hdev = to_hid_device(dev);
        struct wacom *wacom = hid_get_drvdata(hdev);
        u8 new_speed;

        if (kstrtou8(buf, 0, &new_speed))
                return -EINVAL;

        if (new_speed != 0 && new_speed != 1)
                return -EINVAL;

        wacom_bt_query_tablet_data(hdev, new_speed, &wacom->wacom_wac.features);

        return count;
}

static DEVICE_ATTR(speed, DEV_ATTR_RW_PERM,
                wacom_show_speed, wacom_store_speed);


static ssize_t wacom_show_remote_mode(struct kobject *kobj,
                                      struct kobj_attribute *kattr,
                                      char *buf, int index)
{
        struct device *dev = kobj_to_dev(kobj->parent);
        struct hid_device *hdev = to_hid_device(dev);
        struct wacom *wacom = hid_get_drvdata(hdev);
        u8 mode;

        mode = wacom->led.groups[index].select;
        if (mode >= 0 && mode < 3)
                return snprintf(buf, PAGE_SIZE, "%d\n", mode);
        else
                return snprintf(buf, PAGE_SIZE, "%d\n", -1);
}

#define DEVICE_EKR_ATTR_GROUP(SET_ID)                                   \
static ssize_t wacom_show_remote##SET_ID##_mode(struct kobject *kobj,   \
                               struct kobj_attribute *kattr, char *buf) \
{                                                                       \
        return wacom_show_remote_mode(kobj, kattr, buf, SET_ID);        \
}                                                                       \
static struct kobj_attribute remote##SET_ID##_mode_attr = {             \
        .attr = {.name = "remote_mode",                                 \
                .mode = DEV_ATTR_RO_PERM},                              \
        .show = wacom_show_remote##SET_ID##_mode,                       \
};                                                                      \
static struct attribute *remote##SET_ID##_serial_attrs[] = {            \
        &remote##SET_ID##_mode_attr.attr,                               \
        NULL                                                            \
};                                                                      \
static struct attribute_group remote##SET_ID##_serial_group = {         \
        .name = NULL,                                                   \
        .attrs = remote##SET_ID##_serial_attrs,                         \
}

DEVICE_EKR_ATTR_GROUP(0);
DEVICE_EKR_ATTR_GROUP(1);
DEVICE_EKR_ATTR_GROUP(2);
DEVICE_EKR_ATTR_GROUP(3);
DEVICE_EKR_ATTR_GROUP(4);

static int wacom_remote_create_attr_group(struct wacom *wacom, __u32 serial,
                                          int index)
{
        int error = 0;
        struct wacom_remote *remote = wacom->remote;

        remote->remotes[index].group.name = devm_kasprintf(&wacom->hdev->dev,
                                                          GFP_KERNEL,
                                                          "%d", serial);
        if (!remote->remotes[index].group.name)
                return -ENOMEM;

        error = __wacom_devm_sysfs_create_group(wacom, remote->remote_dir,
                                                &remote->remotes[index].group);
        if (error) {
                remote->remotes[index].group.name = NULL;
                hid_err(wacom->hdev,
                        "cannot create sysfs group err: %d\n", error);
                return error;
        }

        return 0;
}

static int wacom_cmd_unpair_remote(struct wacom *wacom, unsigned char selector)
{
        const size_t buf_size = 2;
        unsigned char *buf;
        int retval;

        buf = kzalloc(buf_size, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        buf[0] = WAC_CMD_DELETE_PAIRING;
        buf[1] = selector;

        retval = wacom_set_report(wacom->hdev, HID_OUTPUT_REPORT, buf,
                                  buf_size, WAC_CMD_RETRIES);
        kfree(buf);

        return retval;
}

static ssize_t wacom_store_unpair_remote(struct kobject *kobj,
                                         struct kobj_attribute *attr,
                                         const char *buf, size_t count)
{
        unsigned char selector = 0;
        struct device *dev = kobj_to_dev(kobj->parent);
        struct hid_device *hdev = to_hid_device(dev);
        struct wacom *wacom = hid_get_drvdata(hdev);
        int err;

        if (!strncmp(buf, "*\n", 2)) {
                selector = WAC_CMD_UNPAIR_ALL;
        } else {
                hid_info(wacom->hdev, "remote: unrecognized unpair code: %s\n",
                         buf);
                return -1;
        }

        mutex_lock(&wacom->lock);

        err = wacom_cmd_unpair_remote(wacom, selector);
        mutex_unlock(&wacom->lock);

        return err < 0 ? err : count;
}

static struct kobj_attribute unpair_remote_attr = {
        .attr = {.name = "unpair_remote", .mode = 0200},
        .store = wacom_store_unpair_remote,
};

static const struct attribute *remote_unpair_attrs[] = {
        &unpair_remote_attr.attr,
        NULL
};

static void wacom_remotes_destroy(void *data)
{
        struct wacom *wacom = data;
        struct wacom_remote *remote = wacom->remote;

        if (!remote)
                return;

        kobject_put(remote->remote_dir);
        kfifo_free(&remote->remote_fifo);
        wacom->remote = NULL;
}

static int wacom_initialize_remotes(struct wacom *wacom)
{
        int error = 0;
        struct wacom_remote *remote;
        int i;

        if (wacom->wacom_wac.features.type != REMOTE)
                return 0;

        remote = devm_kzalloc(&wacom->hdev->dev, sizeof(*wacom->remote),
                              GFP_KERNEL);
        if (!remote)
                return -ENOMEM;

        wacom->remote = remote;

        spin_lock_init(&remote->remote_lock);

        error = kfifo_alloc(&remote->remote_fifo,
                        5 * sizeof(struct wacom_remote_data),
                        GFP_KERNEL);
        if (error) {
                hid_err(wacom->hdev, "failed allocating remote_fifo\n");
                return -ENOMEM;
        }

        remote->remotes[0].group = remote0_serial_group;
        remote->remotes[1].group = remote1_serial_group;
        remote->remotes[2].group = remote2_serial_group;
        remote->remotes[3].group = remote3_serial_group;
        remote->remotes[4].group = remote4_serial_group;

        remote->remote_dir = kobject_create_and_add("wacom_remote",
                                                    &wacom->hdev->dev.kobj);
        if (!remote->remote_dir)
                return -ENOMEM;

        error = sysfs_create_files(remote->remote_dir, remote_unpair_attrs);

        if (error) {
                hid_err(wacom->hdev,
                        "cannot create sysfs group err: %d\n", error);
                return error;
        }

        for (i = 0; i < WACOM_MAX_REMOTES; i++) {
                wacom->led.groups[i].select = WACOM_STATUS_UNKNOWN;
                remote->remotes[i].serial = 0;
        }

        error = devm_add_action_or_reset(&wacom->hdev->dev,
                                         wacom_remotes_destroy, wacom);
        if (error)
                return error;

        return 0;
}

static struct input_dev *wacom_allocate_input(struct wacom *wacom)
{
        struct input_dev *input_dev;
        struct hid_device *hdev = wacom->hdev;
        struct wacom_wac *wacom_wac = &(wacom->wacom_wac);

        input_dev = devm_input_allocate_device(&hdev->dev);
        if (!input_dev)
                return NULL;

        input_dev->name = wacom_wac->features.name;
        input_dev->phys = hdev->phys;
        input_dev->dev.parent = &hdev->dev;
        input_dev->open = wacom_open;
        input_dev->close = wacom_close;
        input_dev->uniq = hdev->uniq;
        input_dev->id.bustype = hdev->bus;
        input_dev->id.vendor  = hdev->vendor;
        input_dev->id.product = wacom_wac->pid ? wacom_wac->pid : hdev->product;
        input_dev->id.version = hdev->version;
        input_set_drvdata(input_dev, wacom);

        return input_dev;
}

static int wacom_allocate_inputs(struct wacom *wacom)
{
        struct wacom_wac *wacom_wac = &(wacom->wacom_wac);

        wacom_wac->pen_input = wacom_allocate_input(wacom);
        wacom_wac->touch_input = wacom_allocate_input(wacom);
        wacom_wac->pad_input = wacom_allocate_input(wacom);
        if (!wacom_wac->pen_input ||
            !wacom_wac->touch_input ||
            !wacom_wac->pad_input)
                return -ENOMEM;

        wacom_wac->pen_input->name = wacom_wac->pen_name;
        wacom_wac->touch_input->name = wacom_wac->touch_name;
        wacom_wac->pad_input->name = wacom_wac->pad_name;

        return 0;
}

static int wacom_register_inputs(struct wacom *wacom)
{
        struct input_dev *pen_input_dev, *touch_input_dev, *pad_input_dev;
        struct wacom_wac *wacom_wac = &(wacom->wacom_wac);
        int error = 0;

        pen_input_dev = wacom_wac->pen_input;
        touch_input_dev = wacom_wac->touch_input;
        pad_input_dev = wacom_wac->pad_input;

        if (!pen_input_dev || !touch_input_dev || !pad_input_dev)
                return -EINVAL;

        error = wacom_setup_pen_input_capabilities(pen_input_dev, wacom_wac);
        if (error) {
                /* no pen in use on this interface */
                input_free_device(pen_input_dev);
                wacom_wac->pen_input = NULL;
                pen_input_dev = NULL;
        } else {
                error = input_register_device(pen_input_dev);
                if (error)
                        goto fail;
        }

        error = wacom_setup_touch_input_capabilities(touch_input_dev, wacom_wac);
        if (error) {
                /* no touch in use on this interface */
                input_free_device(touch_input_dev);
                wacom_wac->touch_input = NULL;
                touch_input_dev = NULL;
        } else {
                error = input_register_device(touch_input_dev);
                if (error)
                        goto fail;
        }

        error = wacom_setup_pad_input_capabilities(pad_input_dev, wacom_wac);
        if (error) {
                /* no pad in use on this interface */
                input_free_device(pad_input_dev);
                wacom_wac->pad_input = NULL;
                pad_input_dev = NULL;
        } else {
                error = input_register_device(pad_input_dev);
                if (error)
                        goto fail;
        }

        return 0;

fail:
        wacom_wac->pad_input = NULL;
        wacom_wac->touch_input = NULL;
        wacom_wac->pen_input = NULL;
        return error;
}

/*
 * Not all devices report physical dimensions from HID.
 * Compute the default from hardcoded logical dimension
 * and resolution before driver overwrites them.
 */
static void wacom_set_default_phy(struct wacom_features *features)
{
        if (features->x_resolution) {
                features->x_phy = (features->x_max * 100) /
                                        features->x_resolution;
                features->y_phy = (features->y_max * 100) /
                                        features->y_resolution;
        }
}

static void wacom_calculate_res(struct wacom_features *features)
{
        /* set unit to "100th of a mm" for devices not reported by HID */
        if (!features->unit) {
                features->unit = 0x11;
                features->unitExpo = -3;
        }

        features->x_resolution = wacom_calc_hid_res(features->x_max,
                                                    features->x_phy,
                                                    features->unit,
                                                    features->unitExpo);
        features->y_resolution = wacom_calc_hid_res(features->y_max,
                                                    features->y_phy,
                                                    features->unit,
                                                    features->unitExpo);
}

void wacom_battery_work(struct work_struct *work)
{
        struct wacom *wacom = container_of(work, struct wacom, battery_work);

        if ((wacom->wacom_wac.features.quirks & WACOM_QUIRK_BATTERY) &&
             !wacom->battery.battery) {
                wacom_initialize_battery(wacom);
        }
        else if (!(wacom->wacom_wac.features.quirks & WACOM_QUIRK_BATTERY) &&
                 wacom->battery.battery) {
                wacom_destroy_battery(wacom);
        }
}

static size_t wacom_compute_pktlen(struct hid_device *hdev)
{
        struct hid_report_enum *report_enum;
        struct hid_report *report;
        size_t size = 0;

        report_enum = hdev->report_enum + HID_INPUT_REPORT;

        list_for_each_entry(report, &report_enum->report_list, list) {
                size_t report_size = hid_report_len(report);
                if (report_size > size)
                        size = report_size;
        }

        return size;
}

static void wacom_update_name(struct wacom *wacom, const char *suffix)
{
        struct wacom_wac *wacom_wac = &wacom->wacom_wac;
        struct wacom_features *features = &wacom_wac->features;
        char name[WACOM_NAME_MAX];

        /* Generic devices name unspecified */
        if ((features->type == HID_GENERIC) && !strcmp("Wacom HID", features->name)) {
                if (strstr(wacom->hdev->name, "Wacom") ||
                    strstr(wacom->hdev->name, "wacom") ||
                    strstr(wacom->hdev->name, "WACOM")) {
                        /* name is in HID descriptor, use it */
                        strlcpy(name, wacom->hdev->name, sizeof(name));

                        /* strip out excess whitespaces */
                        while (1) {
                                char *gap = strstr(name, "  ");
                                if (gap == NULL)
                                        break;
                                /* shift everything including the terminator */
                                memmove(gap, gap+1, strlen(gap));
                        }

                        /* strip off excessive prefixing */
                        if (strstr(name, "Wacom Co.,Ltd. Wacom ") == name) {
                                int n = strlen(name);
                                int x = strlen("Wacom Co.,Ltd. ");
                                memmove(name, name+x, n-x+1);
                        }
                        if (strstr(name, "Wacom Co., Ltd. Wacom ") == name) {
                                int n = strlen(name);
                                int x = strlen("Wacom Co., Ltd. ");
                                memmove(name, name+x, n-x+1);
                        }

                        /* get rid of trailing whitespace */
                        if (name[strlen(name)-1] == ' ')
                                name[strlen(name)-1] = '\0';
                } else {
                        /* no meaningful name retrieved. use product ID */
                        snprintf(name, sizeof(name),
                                 "%s %X", features->name, wacom->hdev->product);
                }
        } else {
                strlcpy(name, features->name, sizeof(name));
        }

        snprintf(wacom_wac->name, sizeof(wacom_wac->name), "%s%s",
                 name, suffix);

        /* Append the device type to the name */
        snprintf(wacom_wac->pen_name, sizeof(wacom_wac->pen_name),
                "%s%s Pen", name, suffix);
        snprintf(wacom_wac->touch_name, sizeof(wacom_wac->touch_name),
                "%s%s Finger", name, suffix);
        snprintf(wacom_wac->pad_name, sizeof(wacom_wac->pad_name),
                "%s%s Pad", name, suffix);
}

static void wacom_release_resources(struct wacom *wacom)
{
        struct hid_device *hdev = wacom->hdev;

        if (!wacom->resources)
                return;

        devres_release_group(&hdev->dev, wacom);

        wacom->resources = false;

        wacom->wacom_wac.pen_input = NULL;
        wacom->wacom_wac.touch_input = NULL;
        wacom->wacom_wac.pad_input = NULL;
}

static int wacom_parse_and_register(struct wacom *wacom, bool wireless)
{
        struct wacom_wac *wacom_wac = &wacom->wacom_wac;
        struct wacom_features *features = &wacom_wac->features;
        struct hid_device *hdev = wacom->hdev;
        int error;
        unsigned int connect_mask = HID_CONNECT_HIDRAW;

        features->pktlen = wacom_compute_pktlen(hdev);
        if (features->pktlen > WACOM_PKGLEN_MAX)
                return -EINVAL;

        if (!devres_open_group(&hdev->dev, wacom, GFP_KERNEL))
                return -ENOMEM;

        wacom->resources = true;

        error = wacom_allocate_inputs(wacom);
        if (error)
                goto fail;

        error = wacom_add_shared_data(hdev);
        if (error)
                goto fail;

        /*
         * Bamboo Pad has a generic hid handling for the Pen, and we switch it
         * into debug mode for the touch part.
         * We ignore the other interfaces.
         */
        if (features->type == BAMBOO_PAD) {
                if (features->pktlen == WACOM_PKGLEN_PENABLED) {
                        features->type = HID_GENERIC;
                } else if ((features->pktlen != WACOM_PKGLEN_BPAD_TOUCH) &&
                           (features->pktlen != WACOM_PKGLEN_BPAD_TOUCH_USB)) {
                        error = -ENODEV;
                        goto fail;
                }
        }

        /* set the default size in case we do not get them from hid */
        wacom_set_default_phy(features);

        /* Retrieve the physical and logical size for touch devices */
        wacom_retrieve_hid_descriptor(hdev, features);
        wacom_setup_device_quirks(wacom);

        if (features->device_type == WACOM_DEVICETYPE_NONE &&
            features->type != WIRELESS) {
                error = features->type == HID_GENERIC ? -ENODEV : 0;

                dev_warn(&hdev->dev, "Unknown device_type for '%s'. %s.",
                         hdev->name,
                         error ? "Ignoring" : "Assuming pen");

                if (error)
                        goto fail;

                features->device_type |= WACOM_DEVICETYPE_PEN;
        }

        wacom_calculate_res(features);

        wacom_update_name(wacom, wireless ? " (WL)" : "");

        if (wacom_wac->features.device_type & WACOM_DEVICETYPE_TOUCH)
                wacom_wac->shared->touch = hdev;
        else if (wacom_wac->features.device_type & WACOM_DEVICETYPE_PEN)
                wacom_wac->shared->pen = hdev;

        if (!(features->device_type & WACOM_DEVICETYPE_WL_MONITOR) &&
             (features->quirks & WACOM_QUIRK_BATTERY)) {
                error = wacom_initialize_battery(wacom);
                if (error)
                        goto fail;
        }

        error = wacom_register_inputs(wacom);
        if (error)
                goto fail;

        if (wacom->wacom_wac.features.device_type & WACOM_DEVICETYPE_PAD) {
                error = wacom_initialize_leds(wacom);
                if (error)
                        goto fail;

                error = wacom_initialize_remotes(wacom);
                if (error)
                        goto fail;
        }

        if (features->type == HID_GENERIC)
                connect_mask |= HID_CONNECT_DRIVER;

        /* Regular HID work starts now */
        error = hid_hw_start(hdev, connect_mask);
        if (error) {
                hid_err(hdev, "hw start failed\n");
                goto fail;
        }

        if (!wireless) {
                /* Note that if query fails it is not a hard failure */
                wacom_query_tablet_data(hdev, features);
        }

        /* touch only Bamboo doesn't support pen */
        if ((features->type == BAMBOO_TOUCH) &&
            (features->device_type & WACOM_DEVICETYPE_PEN)) {
                error = -ENODEV;
                goto fail_quirks;
        }

        /* pen only Bamboo neither support touch nor pad */
        if ((features->type == BAMBOO_PEN) &&
            ((features->device_type & WACOM_DEVICETYPE_TOUCH) ||
            (features->device_type & WACOM_DEVICETYPE_PAD))) {
                error = -ENODEV;
                goto fail_quirks;
        }

        if (features->device_type & WACOM_DEVICETYPE_WL_MONITOR)
                error = hid_hw_open(hdev);

        if ((wacom_wac->features.type == INTUOSHT ||
             wacom_wac->features.type == INTUOSHT2) &&
            (wacom_wac->features.device_type & WACOM_DEVICETYPE_TOUCH)) {
                wacom_wac->shared->type = wacom_wac->features.type;
                wacom_wac->shared->touch_input = wacom_wac->touch_input;
        }

        devres_close_group(&hdev->dev, wacom);

        return 0;

fail_quirks:
        hid_hw_stop(hdev);
fail:
        wacom_release_resources(wacom);
        return error;
}

static void wacom_wireless_work(struct work_struct *work)
{
        struct wacom *wacom = container_of(work, struct wacom, wireless_work);
        struct usb_device *usbdev = wacom->usbdev;
        struct wacom_wac *wacom_wac = &wacom->wacom_wac;
        struct hid_device *hdev1, *hdev2;
        struct wacom *wacom1, *wacom2;
        struct wacom_wac *wacom_wac1, *wacom_wac2;
        int error;

        /*
         * Regardless if this is a disconnect or a new tablet,
         * remove any existing input and battery devices.
         */

        wacom_destroy_battery(wacom);

        /* Stylus interface */
        hdev1 = usb_get_intfdata(usbdev->config->interface[1]);
        wacom1 = hid_get_drvdata(hdev1);
        wacom_wac1 = &(wacom1->wacom_wac);
        wacom_release_resources(wacom1);

        /* Touch interface */
        hdev2 = usb_get_intfdata(usbdev->config->interface[2]);
        wacom2 = hid_get_drvdata(hdev2);
        wacom_wac2 = &(wacom2->wacom_wac);
        wacom_release_resources(wacom2);

        if (wacom_wac->pid == 0) {
                hid_info(wacom->hdev, "wireless tablet disconnected\n");
        } else {
                const struct hid_device_id *id = wacom_ids;

                hid_info(wacom->hdev, "wireless tablet connected with PID %x\n",
                         wacom_wac->pid);

                while (id->bus) {
                        if (id->vendor == USB_VENDOR_ID_WACOM &&
                            id->product == wacom_wac->pid)
                                break;
                        id++;
                }

                if (!id->bus) {
                        hid_info(wacom->hdev, "ignoring unknown PID.\n");
                        return;
                }

                /* Stylus interface */
                wacom_wac1->features =
                        *((struct wacom_features *)id->driver_data);

                wacom_wac1->pid = wacom_wac->pid;
                hid_hw_stop(hdev1);
                error = wacom_parse_and_register(wacom1, true);
                if (error)
                        goto fail;

                /* Touch interface */
                if (wacom_wac1->features.touch_max ||
                    (wacom_wac1->features.type >= INTUOSHT &&
                    wacom_wac1->features.type <= BAMBOO_PT)) {
                        wacom_wac2->features =
                                *((struct wacom_features *)id->driver_data);
                        wacom_wac2->pid = wacom_wac->pid;
                        hid_hw_stop(hdev2);
                        error = wacom_parse_and_register(wacom2, true);
                        if (error)
                                goto fail;
                }

                strlcpy(wacom_wac->name, wacom_wac1->name,
                        sizeof(wacom_wac->name));
                error = wacom_initialize_battery(wacom);
                if (error)
                        goto fail;
        }

        return;

fail:
        wacom_release_resources(wacom1);
        wacom_release_resources(wacom2);
        return;
}

static void wacom_remote_destroy_one(struct wacom *wacom, unsigned int index)
{
        struct wacom_remote *remote = wacom->remote;
        u32 serial = remote->remotes[index].serial;
        int i;
        unsigned long flags;

        spin_lock_irqsave(&remote->remote_lock, flags);
        remote->remotes[index].registered = false;
        spin_unlock_irqrestore(&remote->remote_lock, flags);

        if (remote->remotes[index].battery.battery)
                devres_release_group(&wacom->hdev->dev,
                                     &remote->remotes[index].battery.bat_desc);

        if (remote->remotes[index].group.name)
                devres_release_group(&wacom->hdev->dev,
                                     &remote->remotes[index]);

        for (i = 0; i < WACOM_MAX_REMOTES; i++) {
                if (remote->remotes[i].serial == serial) {
                        remote->remotes[i].serial = 0;
                        remote->remotes[i].group.name = NULL;
                        remote->remotes[i].registered = false;
                        remote->remotes[i].battery.battery = NULL;
                        wacom->led.groups[i].select = WACOM_STATUS_UNKNOWN;
                }
        }
}

static int wacom_remote_create_one(struct wacom *wacom, u32 serial,
                                   unsigned int index)
{
        struct wacom_remote *remote = wacom->remote;
        struct device *dev = &wacom->hdev->dev;
        int error, k;

        /* A remote can pair more than once with an EKR,
         * check to make sure this serial isn't already paired.
         */
        for (k = 0; k < WACOM_MAX_REMOTES; k++) {
                if (remote->remotes[k].serial == serial)
                        break;
        }

        if (k < WACOM_MAX_REMOTES) {
                remote->remotes[index].serial = serial;
                return 0;
        }

        if (!devres_open_group(dev, &remote->remotes[index], GFP_KERNEL))
                return -ENOMEM;

        error = wacom_remote_create_attr_group(wacom, serial, index);
        if (error)
                goto fail;

        remote->remotes[index].input = wacom_allocate_input(wacom);
        if (!remote->remotes[index].input) {
                error = -ENOMEM;
                goto fail;
        }
        remote->remotes[index].input->uniq = remote->remotes[index].group.name;
        remote->remotes[index].input->name = wacom->wacom_wac.pad_name;

        if (!remote->remotes[index].input->name) {
                error = -EINVAL;
                goto fail;
        }

        error = wacom_setup_pad_input_capabilities(remote->remotes[index].input,
                                                   &wacom->wacom_wac);
        if (error)
                goto fail;

        remote->remotes[index].serial = serial;

        error = input_register_device(remote->remotes[index].input);
        if (error)
                goto fail;

        error = wacom_led_groups_alloc_and_register_one(
                                        &remote->remotes[index].input->dev,
                                        wacom, index, 3, true);
        if (error)
                goto fail;

        remote->remotes[index].registered = true;

        devres_close_group(dev, &remote->remotes[index]);
        return 0;

fail:
        devres_release_group(dev, &remote->remotes[index]);
        remote->remotes[index].serial = 0;
        return error;
}

static int wacom_remote_attach_battery(struct wacom *wacom, int index)
{
        struct wacom_remote *remote = wacom->remote;
        int error;

        if (!remote->remotes[index].registered)
                return 0;

        if (remote->remotes[index].battery.battery)
                return 0;

        if (wacom->led.groups[index].select == WACOM_STATUS_UNKNOWN)
                return 0;

        error = __wacom_initialize_battery(wacom,
                                        &wacom->remote->remotes[index].battery);
        if (error)
                return error;

        return 0;
}

static void wacom_remote_work(struct work_struct *work)
{
        struct wacom *wacom = container_of(work, struct wacom, remote_work);
        struct wacom_remote *remote = wacom->remote;
        struct wacom_remote_data data;
        unsigned long flags;
        unsigned int count;
        u32 serial;
        int i;

        spin_lock_irqsave(&remote->remote_lock, flags);

        count = kfifo_out(&remote->remote_fifo, &data, sizeof(data));

        if (count != sizeof(data)) {
                hid_err(wacom->hdev,
                        "workitem triggered without status available\n");
                spin_unlock_irqrestore(&remote->remote_lock, flags);
                return;
        }

        if (!kfifo_is_empty(&remote->remote_fifo))
                wacom_schedule_work(&wacom->wacom_wac, WACOM_WORKER_REMOTE);

        spin_unlock_irqrestore(&remote->remote_lock, flags);

        for (i = 0; i < WACOM_MAX_REMOTES; i++) {
                serial = data.remote[i].serial;
                if (data.remote[i].connected) {

                        if (remote->remotes[i].serial == serial) {
                                wacom_remote_attach_battery(wacom, i);
                                continue;
                        }

                        if (remote->remotes[i].serial)
                                wacom_remote_destroy_one(wacom, i);

                        wacom_remote_create_one(wacom, serial, i);

                } else if (remote->remotes[i].serial) {
                        wacom_remote_destroy_one(wacom, i);
                }
        }
}

static int wacom_probe(struct hid_device *hdev,
                const struct hid_device_id *id)
{
        struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
        struct usb_device *dev = interface_to_usbdev(intf);
        struct wacom *wacom;
        struct wacom_wac *wacom_wac;
        struct wacom_features *features;
        int error;

        if (!id->driver_data)
                return -EINVAL;

        hdev->quirks |= HID_QUIRK_NO_INIT_REPORTS;

        /* hid-core sets this quirk for the boot interface */
        hdev->quirks &= ~HID_QUIRK_NOGET;

        wacom = devm_kzalloc(&hdev->dev, sizeof(struct wacom), GFP_KERNEL);
        if (!wacom)
                return -ENOMEM;

        hid_set_drvdata(hdev, wacom);
        wacom->hdev = hdev;

        wacom_wac = &wacom->wacom_wac;
        wacom_wac->features = *((struct wacom_features *)id->driver_data);
        features = &wacom_wac->features;

        if (features->check_for_hid_type && features->hid_type != hdev->type) {
                error = -ENODEV;
                goto fail;
        }

        wacom_wac->hid_data.inputmode = -1;
        wacom_wac->mode_report = -1;

        wacom->usbdev = dev;
        wacom->intf = intf;
        mutex_init(&wacom->lock);
        INIT_WORK(&wacom->wireless_work, wacom_wireless_work);
        INIT_WORK(&wacom->battery_work, wacom_battery_work);
        INIT_WORK(&wacom->remote_work, wacom_remote_work);

        /* ask for the report descriptor to be loaded by HID */
        error = hid_parse(hdev);
        if (error) {
                hid_err(hdev, "parse failed\n");
                goto fail;
        }

        error = wacom_parse_and_register(wacom, false);
        if (error)
                goto fail;

        if (hdev->bus == BUS_BLUETOOTH) {
                error = device_create_file(&hdev->dev, &dev_attr_speed);
                if (error)
                        hid_warn(hdev,
                                 "can't create sysfs speed attribute err: %d\n",
                                 error);
        }

        return 0;

fail:
        hid_set_drvdata(hdev, NULL);
        return error;
}

static void wacom_remove(struct hid_device *hdev)
{
        struct wacom *wacom = hid_get_drvdata(hdev);
        struct wacom_wac *wacom_wac = &wacom->wacom_wac;
        struct wacom_features *features = &wacom_wac->features;

        if (features->device_type & WACOM_DEVICETYPE_WL_MONITOR)
                hid_hw_close(hdev);

        hid_hw_stop(hdev);

        cancel_work_sync(&wacom->wireless_work);
        cancel_work_sync(&wacom->battery_work);
        cancel_work_sync(&wacom->remote_work);
        if (hdev->bus == BUS_BLUETOOTH)
                device_remove_file(&hdev->dev, &dev_attr_speed);

        hid_set_drvdata(hdev, NULL);
}

#ifdef CONFIG_PM
static int wacom_resume(struct hid_device *hdev)
{
        struct wacom *wacom = hid_get_drvdata(hdev);
        struct wacom_features *features = &wacom->wacom_wac.features;

        mutex_lock(&wacom->lock);

        /* switch to wacom mode first */
        wacom_query_tablet_data(hdev, features);
        wacom_led_control(wacom);

        mutex_unlock(&wacom->lock);

        return 0;
}

static int wacom_reset_resume(struct hid_device *hdev)
{
        return wacom_resume(hdev);
}
#endif /* CONFIG_PM */

static struct hid_driver wacom_driver = {
        .name =         "wacom",
        .id_table =     wacom_ids,
        .probe =        wacom_probe,
        .remove =       wacom_remove,
        .report =       wacom_wac_report,
#ifdef CONFIG_PM
        .resume =       wacom_resume,
        .reset_resume = wacom_reset_resume,
#endif
        .raw_event =    wacom_raw_event,
};
module_hid_driver(wacom_driver);

MODULE_VERSION(DRIVER_VERSION);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE(DRIVER_LICENSE);