linux/drivers/hid/hid-speedlink.c
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   1/*
   2 *  HID driver for Speedlink Vicious and Divine Cezanne (USB mouse).
   3 *  Fixes "jumpy" cursor and removes nonexistent keyboard LEDS from
   4 *  the HID descriptor.
   5 *
   6 *  Copyright (c) 2011, 2013 Stefan Kriwanek <dev@stefankriwanek.de>
   7 */
   8
   9/*
  10 * This program is free software; you can redistribute it and/or modify it
  11 * under the terms of the GNU General Public License as published by the Free
  12 * Software Foundation; either version 2 of the License, or (at your option)
  13 * any later version.
  14 */
  15
  16#include <linux/device.h>
  17#include <linux/hid.h>
  18#include <linux/module.h>
  19
  20#include "hid-ids.h"
  21
  22static const struct hid_device_id speedlink_devices[] = {
  23        { HID_USB_DEVICE(USB_VENDOR_ID_X_TENSIONS, USB_DEVICE_ID_SPEEDLINK_VAD_CEZANNE)},
  24        { }
  25};
  26
  27static int speedlink_input_mapping(struct hid_device *hdev,
  28                struct hid_input *hi,
  29                struct hid_field *field, struct hid_usage *usage,
  30                unsigned long **bit, int *max)
  31{
  32        /*
  33         * The Cezanne mouse has a second "keyboard" USB endpoint for it is
  34         * able to map keyboard events to the button presses.
  35         * It sends a standard keyboard report descriptor, though, whose
  36         * LEDs we ignore.
  37         */
  38        switch (usage->hid & HID_USAGE_PAGE) {
  39        case HID_UP_LED:
  40                return -1;
  41        }
  42        return 0;
  43}
  44
  45static int speedlink_event(struct hid_device *hdev, struct hid_field *field,
  46                struct hid_usage *usage, __s32 value)
  47{
  48        /* No other conditions due to usage_table. */
  49
  50        /* This fixes the "jumpy" cursor occuring due to invalid events sent
  51         * by the device. Some devices only send them with value==+256, others
  52         * don't. However, catching abs(value)>=256 is restrictive enough not
  53         * to interfere with devices that were bug-free (has been tested).
  54         */
  55        if (abs(value) >= 256)
  56                return 1;
  57        /* Drop useless distance 0 events (on button clicks etc.) as well */
  58        if (value == 0)
  59                return 1;
  60
  61        return 0;
  62}
  63
  64MODULE_DEVICE_TABLE(hid, speedlink_devices);
  65
  66static const struct hid_usage_id speedlink_grabbed_usages[] = {
  67        { HID_GD_X, EV_REL, 0 },
  68        { HID_GD_Y, EV_REL, 1 },
  69        { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
  70};
  71
  72static struct hid_driver speedlink_driver = {
  73        .name = "speedlink",
  74        .id_table = speedlink_devices,
  75        .usage_table = speedlink_grabbed_usages,
  76        .input_mapping = speedlink_input_mapping,
  77        .event = speedlink_event,
  78};
  79module_hid_driver(speedlink_driver);
  80
  81MODULE_LICENSE("GPL");
  82
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