Quelle  hid-viewsonic.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0+
/*
 *  HID driver for ViewSonic devices not fully compliant with HID standard
 *
 *  Copyright (c) 2017 Nikolai Kondrashov
 */

/*
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 */

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

#include "hid-ids.h"

/* Size of the original descriptor of PD1011 signature pad */
#define PD1011_RDESC_ORIG_SIZE 408

/* Fixed report descriptor of PD1011 signature pad */
static const __u8 pd1011_rdesc_fixed[] = {
 0x05, 0x0D,             /*  Usage Page (Digitizer),             */
 0x09, 0x01,             /*  Usage (Digitizer),                  */
 0xA1, 0x01,             /*  Collection (Application),           */
 0x85, 0x02,             /*      Report ID (2),                  */
 0x09, 0x20,             /*      Usage (Stylus),                 */
 0xA0,                   /*      Collection (Physical),          */
 0x75, 0x10,             /*          Report Size (16),           */
 0x95, 0x01,             /*          Report Count (1),           */
 0xA4,                   /*          Push,                       */
 0x05, 0x01,             /*          Usage Page (Desktop),       */
 0x65, 0x13,             /*          Unit (Inch),                */
 0x55, 0xFD,             /*          Unit Exponent (-3),         */
 0x34,                   /*          Physical Minimum (0),       */
 0x09, 0x30,             /*          Usage (X),                  */
 0x46, 0x5D, 0x21,       /*          Physical Maximum (8541),    */
 0x27, 0x80, 0xA9,
  0x00, 0x00,     /*          Logical Maximum (43392),    */
 0x81, 0x02,             /*          Input (Variable),           */
 0x09, 0x31,             /*          Usage (Y),                  */
 0x46, 0xDA, 0x14,       /*          Physical Maximum (5338),    */
 0x26, 0xF0, 0x69,       /*          Logical Maximum (27120),    */
 0x81, 0x02,             /*          Input (Variable),           */
 0xB4,                   /*          Pop,                        */
 0x14,                   /*          Logical Minimum (0),        */
 0x25, 0x01,             /*          Logical Maximum (1),        */
 0x75, 0x01,             /*          Report Size (1),            */
 0x95, 0x01,             /*          Report Count (1),           */
 0x81, 0x03,             /*          Input (Constant, Variable), */
 0x09, 0x32,             /*          Usage (In Range),           */
 0x09, 0x42,             /*          Usage (Tip Switch),         */
 0x95, 0x02,             /*          Report Count (2),           */
 0x81, 0x02,             /*          Input (Variable),           */
 0x95, 0x05,             /*          Report Count (5),           */
 0x81, 0x03,             /*          Input (Constant, Variable), */
 0x75, 0x10,             /*          Report Size (16),           */
 0x95, 0x01,             /*          Report Count (1),           */
 0x09, 0x30,             /*          Usage (Tip Pressure),       */
 0x15, 0x05,             /*          Logical Minimum (5),        */
 0x26, 0xFF, 0x07,       /*          Logical Maximum (2047),     */
 0x81, 0x02,             /*          Input (Variable),           */
 0x75, 0x10,             /*          Report Size (16),           */
 0x95, 0x01,             /*          Report Count (1),           */
 0x81, 0x03,             /*          Input (Constant, Variable), */
 0xC0,                   /*      End Collection,                 */
 0xC0                    /*  End Collection                      */
};

static const __u8 *viewsonic_report_fixup(struct hid_device *hdev, __u8 *rdesc,
       unsigned int *rsize)
{
 switch (hdev->product) {
 case USB_DEVICE_ID_VIEWSONIC_PD1011:
 case USB_DEVICE_ID_SIGNOTEC_VIEWSONIC_PD1011:
  if (*rsize == PD1011_RDESC_ORIG_SIZE) {
   *rsize = sizeof(pd1011_rdesc_fixed);
   return pd1011_rdesc_fixed;
  }
  break;
 }

 return rdesc;
}

static const struct hid_device_id viewsonic_devices[] = {
 { HID_USB_DEVICE(USB_VENDOR_ID_VIEWSONIC,
    USB_DEVICE_ID_VIEWSONIC_PD1011) },
 { HID_USB_DEVICE(USB_VENDOR_ID_SIGNOTEC,
    USB_DEVICE_ID_SIGNOTEC_VIEWSONIC_PD1011) },
 { }
};
MODULE_DEVICE_TABLE(hid, viewsonic_devices);

static struct hid_driver viewsonic_driver = {
 .name = "viewsonic",
 .id_table = viewsonic_devices,
 .report_fixup = viewsonic_report_fixup,
};
module_hid_driver(viewsonic_driver);

MODULE_DESCRIPTION("HID driver for ViewSonic devices not fully compliant with HID standard");
MODULE_LICENSE("GPL");