LXR linux/drivers/hid/hid-speedlink.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  HID driver for Speedlink Vicious and Divine Cezanne (USB mouse).
   4 *  Fixes "jumpy" cursor and removes nonexistent keyboard LEDS from
   5 *  the HID descriptor.
   6 *
   7 *  Copyright (c) 2011, 2013 Stefan Kriwanek <dev@stefankriwanek.de>
   8 */
   9
  10/*
  11 */
  12
  13#include <linux/device.h>
  14#include <linux/hid.h>
  15#include <linux/module.h>
  16
  17#include "hid-ids.h"
  18
  19static const struct hid_device_id speedlink_devices[] = {
  20        { HID_USB_DEVICE(USB_VENDOR_ID_X_TENSIONS, USB_DEVICE_ID_SPEEDLINK_VAD_CEZANNE)},
  21        { }
  22};
  23
  24static int speedlink_input_mapping(struct hid_device *hdev,
  25                struct hid_input *hi,
  26                struct hid_field *field, struct hid_usage *usage,
  27                unsigned long **bit, int *max)
  28{
  29        /*
  30         * The Cezanne mouse has a second "keyboard" USB endpoint for it is
  31         * able to map keyboard events to the button presses.
  32         * It sends a standard keyboard report descriptor, though, whose
  33         * LEDs we ignore.
  34         */
  35        switch (usage->hid & HID_USAGE_PAGE) {
  36        case HID_UP_LED:
  37                return -1;
  38        }
  39        return 0;
  40}
  41
  42static int speedlink_event(struct hid_device *hdev, struct hid_field *field,
  43                struct hid_usage *usage, __s32 value)
  44{
  45        /* No other conditions due to usage_table. */
  46
  47        /* This fixes the "jumpy" cursor occuring due to invalid events sent
  48         * by the device. Some devices only send them with value==+256, others
  49         * don't. However, catching abs(value)>=256 is restrictive enough not
  50         * to interfere with devices that were bug-free (has been tested).
  51         */
  52        if (abs(value) >= 256)
  53                return 1;
  54        /* Drop useless distance 0 events (on button clicks etc.) as well */
  55        if (value == 0)
  56                return 1;
  57
  58        return 0;
  59}
  60
  61MODULE_DEVICE_TABLE(hid, speedlink_devices);
  62
  63static const struct hid_usage_id speedlink_grabbed_usages[] = {
  64        { HID_GD_X, EV_REL, 0 },
  65        { HID_GD_Y, EV_REL, 1 },
  66        { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
  67};
  68
  69static struct hid_driver speedlink_driver = {
  70        .name = "speedlink",
  71        .id_table = speedlink_devices,
  72        .usage_table = speedlink_grabbed_usages,
  73        .input_mapping = speedlink_input_mapping,
  74        .event = speedlink_event,
  75};
  76module_hid_driver(speedlink_driver);
  77
  78MODULE_LICENSE("GPL");
  79