root/drivers/hid/hid-speedlink.c

DEFINITIONS

1. speedlink_input_mapping
2. speedlink_event

   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 
  19 static 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 
  24 static 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 
  42 static 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 
  61 MODULE_DEVICE_TABLE(hid, speedlink_devices);
  62 
  63 static 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 
  69 static 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 };
  76 module_hid_driver(speedlink_driver);
  77 
  78 MODULE_LICENSE("GPL");