root/drivers/hid/hid-kensington.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  HID driver for Kensington Slimblade Trackball
 *
 *  Copyright (c) 2009 Jiri Kosina
 */

/*
 */

#include <linux/device.h>
#include <linux/input.h>
#include <linux/hid.h>
#include <linux/module.h>

#include "hid-ids.h"

#define ks_map_key(c)   hid_map_usage(hi, usage, bit, max, EV_KEY, (c))

static int ks_input_mapping(struct hid_device *hdev, struct hid_input *hi,
                struct hid_field *field, struct hid_usage *usage,
                unsigned long **bit, int *max)
{
        if ((usage->hid & HID_USAGE_PAGE) != HID_UP_MSVENDOR)
                return 0;

        switch (usage->hid & HID_USAGE) {
        case 0x01: ks_map_key(BTN_MIDDLE);      break;
        case 0x02: ks_map_key(BTN_SIDE);        break;
        default:
                return 0;
        }
        return 1;
}

static const struct hid_device_id ks_devices[] = {
        { HID_USB_DEVICE(USB_VENDOR_ID_KENSINGTON, USB_DEVICE_ID_KS_SLIMBLADE) },
        { }
};
MODULE_DEVICE_TABLE(hid, ks_devices);

static struct hid_driver ks_driver = {
        .name = "kensington",
        .id_table = ks_devices,
        .input_mapping = ks_input_mapping,
};
module_hid_driver(ks_driver);

MODULE_DESCRIPTION("HID driver for Kensington Slimblade Trackball");
MODULE_LICENSE("GPL");