Quelle  wacom_sys.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  USB Wacom tablet support - system specific code
 */

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

#define WAC_MSG_RETRIES  5
#define WAC_CMD_RETRIES  10

#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 void wacom_wac_queue_insert(struct hid_device *hdev,
       struct kfifo_rec_ptr_2 *fifo,
       u8 *raw_data, int size)
{
 bool warned = false;

 while (kfifo_avail(fifo) < size) {
  if (!warned)
   hid_warn(hdev, "%s: kfifo has filled, starting to drop events\n", __func__);
  warned = true;

  kfifo_skip(fifo);
 }

 kfifo_in(fifo, raw_data, size);
}

static void wacom_wac_queue_flush(struct hid_device *hdev,
      struct kfifo_rec_ptr_2 *fifo)
{
 while (!kfifo_is_empty(fifo)) {
  int size = kfifo_peek_len(fifo);
  u8 *buf;
  unsigned int count;
  int err;

  buf = kzalloc(size, GFP_KERNEL);
  if (!buf) {
   kfifo_skip(fifo);
   continue;
  }

  count = kfifo_out(fifo, buf, size);
  if (count != size) {
   // Hard to say what is the "right" action in this
   // circumstance. Skipping the entry and continuing
   // to flush seems reasonable enough, however.
   hid_warn(hdev, "%s: removed fifo entry with unexpected size\n",
     __func__);
   kfree(buf);
   continue;
  }
  err = hid_report_raw_event(hdev, HID_INPUT_REPORT, buf, size, false);
  if (err) {
   hid_warn(hdev, "%s: unable to flush event due to error %d\n",
     __func__, err);
  }

  kfree(buf);
 }
}

static int wacom_wac_pen_serial_enforce(struct hid_device *hdev,
  struct hid_report *report, u8 *raw_data, int report_size)
{
 struct wacom *wacom = hid_get_drvdata(hdev);
 struct wacom_wac *wacom_wac = &wacom->wacom_wac;
 struct wacom_features *features = &wacom_wac->features;
 bool flush = false;
 bool insert = false;
 int i, j;

 if (wacom_wac->serial[0] || !(features->quirks & WACOM_QUIRK_TOOLSERIAL))
  return 0;

 /* Queue events which have invalid tool type or serial number */
 for (i = 0; i < report->maxfield; i++) {
  for (j = 0; j < report->field[i]->maxusage; j++) {
   struct hid_field *field = report->field[i];
   struct hid_usage *usage = &field->usage[j];
   unsigned int equivalent_usage = wacom_equivalent_usage(usage->hid);
   unsigned int offset;
   unsigned int size;
   unsigned int value;

   if (equivalent_usage != HID_DG_INRANGE &&
       equivalent_usage != HID_DG_TOOLSERIALNUMBER &&
       equivalent_usage != WACOM_HID_WD_SERIALHI &&
       equivalent_usage != WACOM_HID_WD_TOOLTYPE)
    continue;

   offset = field->report_offset;
   size = field->report_size;
   value = hid_field_extract(hdev, raw_data+1, offset + j * size, size);

   /* If we go out of range, we need to flush the queue ASAP */
   if (equivalent_usage == HID_DG_INRANGE)
    value = !value;

   if (value) {
    flush = true;
    switch (equivalent_usage) {
    case HID_DG_TOOLSERIALNUMBER:
     wacom_wac->serial[0] = value;
     break;

    case WACOM_HID_WD_SERIALHI:
     wacom_wac->serial[0] |= ((__u64)value) << 32;
     break;

    case WACOM_HID_WD_TOOLTYPE:
     wacom_wac->id[0] = value;
     break;
    }
   }
   else {
    insert = true;
   }
  }
 }

 if (flush)
  wacom_wac_queue_flush(hdev, wacom_wac->pen_fifo);
 else if (insert)
  wacom_wac_queue_insert(hdev, wacom_wac->pen_fifo,
           raw_data, report_size);

 return insert && !flush;
}

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 (wacom->wacom_wac.features.type == BOOTLOADER)
  return 0;

 if (wacom_wac_pen_serial_enforce(hdev, report, raw_data, size))
  return -1;

 wacom->wacom_wac.data = raw_data;

 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_hid_usage_quirk(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;
 unsigned int equivalent_usage = wacom_equivalent_usage(usage->hid);

 /*
 * The Dell Canvas 27 needs to be switched to its vendor-defined
 * report to provide the best resolution.
 */
 if (hdev->vendor == USB_VENDOR_ID_WACOM &&
     hdev->product == 0x4200 &&
     field->application == HID_UP_MSVENDOR) {
  wacom->wacom_wac.mode_report = field->report->id;
  wacom->wacom_wac.mode_value = 2;
 }

 /*
 * 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;
  }
 }

 /*
 * Wacom's AES devices use different vendor-defined usages to
 * report serial number information compared to their branded
 * hardware. The usages are also sometimes ill-defined and do
 * not have the correct logical min/max values set. Lets patch
 * the descriptor to use the branded usage convention and fix
 * the errors.
 */
 if (usage->hid == WACOM_HID_WT_SERIALNUMBER &&
     field->report_size == 16 &&
     field->index + 2 < field->report->maxfield) {
  struct hid_field *a = field->report->field[field->index + 1];
  struct hid_field *b = field->report->field[field->index + 2];

  if (a->maxusage > 0 &&
      a->usage[0].hid == HID_DG_TOOLSERIALNUMBER &&
      a->report_size == 32 &&
      b->maxusage > 0 &&
      b->usage[0].hid == 0xFF000000 &&
      b->report_size == 8) {
   features->quirks |= WACOM_QUIRK_AESPEN;
   usage->hid = WACOM_HID_WD_TOOLTYPE;
   field->logical_minimum = S16_MIN;
   field->logical_maximum = S16_MAX;
   a->logical_minimum = S32_MIN;
   a->logical_maximum = S32_MAX;
   b->usage[0].hid = WACOM_HID_WD_SERIALHI;
   b->logical_minimum = 0;
   b->logical_maximum = U8_MAX;
  }
 }

 /* 2nd-generation Intuos Pro Large has incorrect Y maximum */
 if (hdev->vendor == USB_VENDOR_ID_WACOM &&
     hdev->product == 0x0358 &&
     WACOM_PEN_FIELD(field) &&
     equivalent_usage == HID_GD_Y) {
  field->logical_maximum = 43200;
 }
}

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;
 unsigned int equivalent_usage = wacom_equivalent_usage(usage->hid);
 u8 *data;
 int ret;
 u32 n;

 wacom_hid_usage_quirk(hdev, field, usage);

 switch (equivalent_usage) {
 case WACOM_HID_WD_TOUCH_RING_SETTING:
  wacom->generic_has_leds = true;
  break;
 case HID_DG_CONTACTMAX:
  /* leave touch_max as is if predefined */
  if (!features->touch_max) {
   /* 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 && features->type == HID_GENERIC) {
    ret = hid_report_raw_event(hdev,
     HID_FEATURE_REPORT, data, n, 0);
   } else if (ret == 2 && features->type != HID_GENERIC) {
    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);
 unsigned equivalent_usage = wacom_equivalent_usage(usage->hid);

 /*
* 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;

 wacom_hid_usage_quirk(hdev, field, usage);

 switch (equivalent_usage) {
 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 (wacom_wac->has_mode_change) {
   if (wacom_wac->is_direct_mode)
    features->device_type |= WACOM_DEVICETYPE_DIRECT;
   else
    features->device_type &= ~WACOM_DEVICETYPE_DIRECT;
  }

  if (features->touch_max > 1) {
   if (features->device_type & WACOM_DEVICETYPE_DIRECT)
    input_mt_init_slots(wacom_wac->touch_input,
          wacom_wac->features.touch_max,
          INPUT_MT_DIRECT);
   else
    input_mt_init_slots(wacom_wac->touch_input,
          wacom_wac->features.touch_max,
          INPUT_MT_POINTER);
  }
 }
}

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;
 u32 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 wacom *wacom)
{
 struct hid_device *hdev = wacom->hdev;
 struct wacom_wac *wacom_wac = &wacom->wacom_wac;
 struct wacom_features *features = &wacom_wac->features;

 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 && intf) {
  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 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 (!hid_compare_device_paths(hdev, sibling, '/'))
   return false;
 } else {
  if (!hid_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 (hid_compare_device_paths(hdev, data->dev, '/')) {
   kref_get(&data->kref);
   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) {
   mutex_unlock(&wacom_udev_list_lock);
   return -ENOMEM;
  }

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

 mutex_unlock(&wacom_udev_list_lock);

 wacom_wac->shared = &data->shared;

 retval = devm_add_action_or_reset(&hdev->dev, wacom_remove_shared_data, wacom);
 if (retval)
  return retval;

 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;

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

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

 if (wacom->wacom_wac.pid) { /* wireless connected */
  report_id = WAC_CMD_WL_LED_CONTROL;
  buf_size = 13;
 }
 else if (wacom->wacom_wac.features.type == INTUOSP2_BT) {
  report_id = WAC_CMD_WL_INTUOSP2;
  buf_size = 51;
 }
 buf = kzalloc(buf_size, GFP_KERNEL);
 if (!buf)
  return -ENOMEM;

 if (wacom->wacom_wac.features.type == HID_GENERIC) {
  buf[0] = WAC_CMD_LED_CONTROL_GENERIC;
  buf[1] = wacom->led.llv;
  buf[2] = wacom->led.groups[0].select & 0x03;

 } else 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 if (wacom->wacom_wac.features.type == INTUOSP2_BT) {
  buf[0] = report_id;
  buf[4] = 100; // Power Connection LED (ORANGE)
  buf[5] = 100; // BT Connection LED (BLUE)
  buf[6] = 100; // Paper Mode (RED?)
  buf[7] = 100; // Paper Mode (GREEN?)
  buf[8] = 100; // Paper Mode (BLUE?)
  buf[9] = wacom->led.llv;
  buf[10] = wacom->led.groups[0].select & 0x03;
 }
 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;
 for (unsigned int i = 0; i < wacom->led.count; i++) {
  struct wacom_group_leds *group = &wacom->led.groups[i];

  for (unsigned int j = 0; j < group->count; j++) {
   if (dest == &wacom->led.llv)
    group->leds[j].llv = *dest;
   else if (dest == &wacom->led.hlv)
    group->leds[j].hlv = *dest;
  }
 }

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

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

static const struct attribute_group generic_led_attr_group = {
 .name = "wacom_led",
 .attrs = generic_led_attrs,
};

struct wacom_sysfs_group_devres {
 const 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,
        const 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) {
  devres_free(devres);
  return error;
 }

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

 return 0;
}

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

static void wacom_devm_kfifo_release(struct device *dev, void *res)
{
 struct kfifo_rec_ptr_2 *devres = res;

 kfifo_free(devres);
}

static int wacom_devm_kfifo_alloc(struct wacom *wacom)
{
 struct wacom_wac *wacom_wac = &wacom->wacom_wac;
 int fifo_size = min(PAGE_SIZE, 10 * wacom_wac->features.pktlen);
 struct kfifo_rec_ptr_2 *pen_fifo;
 int error;

 pen_fifo = devres_alloc(wacom_devm_kfifo_release,
         sizeof(struct kfifo_rec_ptr_2),
         GFP_KERNEL);

 if (!pen_fifo)
  return -ENOMEM;

 error = kfifo_alloc(pen_fifo, fifo_size, GFP_KERNEL);
 if (error) {
  devres_free(pen_fifo);
  return error;
 }

 devres_add(&wacom->hdev->dev, pen_fifo);
 wacom_wac->pen_fifo = pen_fifo;

 return 0;
}

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

 if (wacom->led.max_hlv)
  return wacom_rescale(led->hlv, wacom->led.max_hlv, LED_FULL);

 if (wacom->led.max_llv)
  return wacom_rescale(led->llv, wacom->led.max_llv, LED_FULL);

 /* 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_rescale(brightness, LED_FULL, wacom->led.max_llv);
 led->hlv = wacom->led.hlv = wacom_rescale(brightness, LED_FULL, wacom->led.max_hlv);

 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;

 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;
 }

 if (!read_only) {
  led->trigger.name = name;
  if (id == wacom->led.groups[group].select)
   led->trigger.brightness = wacom_leds_brightness_get(led);
  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;
  }
 }

 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_kcalloc(dev, count, sizeof(struct wacom_led), 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_kcalloc(dev, count, sizeof(struct wacom_group_leds),
         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;
}

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 HID_GENERIC:
  if (!wacom->generic_has_leds)
   return 0;
  wacom->led.llv = 100;
  wacom->led.max_llv = 100;

  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,
            &generic_led_attr_group);
  break;

 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 INTUOSP2_BT:
  wacom->led.llv = 50;
  wacom->led.max_llv = 100;
  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;
  }
  return 0;

 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;
 }

 return 0;
}

static void wacom_init_work(struct work_struct *work)
{
 struct wacom *wacom = container_of(work, struct wacom, init_work.work);

 _wacom_query_tablet_data(wacom);
 wacom_led_control(wacom);
}

static void wacom_query_tablet_data(struct wacom *wacom)
{
 schedule_delayed_work(&wacom->init_work, msecs_to_jiffies(1000));
}

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_status != WACOM_POWER_SUPPLY_STATUS_AUTO)
    val->intval = battery->bat_status;
   else 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_BATTERY;
 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 void wacom_aes_battery_handler(struct work_struct *work)
{
 struct wacom *wacom = container_of(work, struct wacom, aes_battery_work.work);

 wacom_destroy_battery(wacom);
}

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 sysfs_emit(buf, "%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;
 return sprintf(buf, "%d\n", mode < 3 ? mode : -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 const 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_work_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) {
  kfifo_free(&remote->remote_fifo);
  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);
  kfifo_free(&remote->remote_fifo);
  kobject_put(remote->remote_dir);
  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_setup_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;
 }

 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;
 }

 error = wacom_setup_pad_input_capabilities(pad_input_dev, wacom_wac);
 if (error) {
  /* no pad events using this interface */
  input_free_device(pad_input_dev);
  wacom_wac->pad_input = NULL;
  pad_input_dev = NULL;
 }

 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) {
  error = input_register_device(pen_input_dev);
  if (error)
   goto fail;
 }

 if (touch_input_dev) {
  error = input_register_device(touch_input_dev);
  if (error)
   goto fail;
 }

 if (pad_input_dev) {
  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 - 20]; /* Leave some room for suffixes */

 /* Generic devices name unspecified */
 if ((features->type == HID_GENERIC) && !strcmp("Wacom HID", features->name)) {
  char *product_name = wacom->hdev->name;

  if (hid_is_usb(wacom->hdev)) {
   struct usb_interface *intf = to_usb_interface(wacom->hdev->dev.parent);
   struct usb_device *dev = interface_to_usbdev(intf);
   if (dev->product != NULL)
    product_name = dev->product;
  }

  if (wacom->hdev->bus == BUS_I2C) {
   snprintf(name, sizeof(name), "%s %X",
     features->name, wacom->hdev->product);
  } else if (strstr(product_name, "Wacom") ||
      strstr(product_name, "wacom") ||
      strstr(product_name, "WACOM")) {
   if (strscpy(name, product_name, sizeof(name)) < 0) {
    hid_warn(wacom->hdev, "String overflow while assembling device name");
   }
  } else {
   snprintf(name, sizeof(name), "Wacom %s", product_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));
  }

  /* get rid of trailing whitespace */
  if (name[strlen(name)-1] == ' ')
   name[strlen(name)-1] = '\0';
 } else {
  if (strscpy(name, features->name, sizeof(name)) < 0) {
   hid_warn(wacom->hdev, "String overflow while assembling device 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 void wacom_set_shared_values(struct wacom_wac *wacom_wac)
{
 if (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;
 }

 if (wacom_wac->has_mute_touch_switch) {
  wacom_wac->shared->has_mute_touch_switch = true;
  /* Hardware touch switch may be off. Wait until
 * we know the switch state to decide is_touch_on.
 * Softkey state should be initialized to "on" to
 * match historic default.
 */
  if (wacom_wac->is_soft_touch_switch)
   wacom_wac->shared->is_touch_on = true;
 }

 if (wacom_wac->shared->has_mute_touch_switch &&
     wacom_wac->shared->touch_input) {
  set_bit(EV_SW, wacom_wac->shared->touch_input->evbit);
  input_set_capability(wacom_wac->shared->touch_input, EV_SW,
         SW_MUTE_DEVICE);
 }
}

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)
  return -ENODEV;

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

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

 wacom->resources = true;

 error = wacom_allocate_inputs(wacom);
 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)" : "");

 /* 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;
 }

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

 error = wacom_setup_inputs(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;
 }

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

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

 if (features->device_type & WACOM_DEVICETYPE_WL_MONITOR) {
  error = hid_hw_open(hdev);
  if (error) {
   hid_err(hdev, "hw open failed\n");
   goto fail_quirks;
  }
 }

 wacom_set_shared_values(wacom_wac);
 devres_close_group(&hdev->dev, wacom);

 return 0;

fail_quirks:
 hid_hw_stop(hdev);
fail:
 wacom_release_resources(wacom);
--> --------------------

--> maximum size reached

--> --------------------