hid-evision.c

 1// SPDX-License-Identifier: GPL-2.0-or-later
 2/*
 3 *  HID driver for EVision devices
 4 *  For now, only ignore bogus consumer reports
 5 *  sent after the keyboard has been configured
 6 *
 7 *  Copyright (c) 2022 Philippe Valembois
 8 */
 9
10#include <linux/device.h>
11#include <linux/input.h>
12#include <linux/hid.h>
13#include <linux/module.h>
14
15#include "hid-ids.h"
16
17static int evision_input_mapping(struct hid_device *hdev, struct hid_input *hi,
18		struct hid_field *field, struct hid_usage *usage,
19		unsigned long **bit, int *max)
20{
21	/* mapping only applies to USB_DEVICE_ID_EVISION_ICL01 */
22	if (hdev->product != USB_DEVICE_ID_EVISION_ICL01)
23		return 0;
24
25	if ((usage->hid & HID_USAGE_PAGE) != HID_UP_CONSUMER)
26		return 0;
27
28	/* Ignore key down event */
29	if ((usage->hid & HID_USAGE) >> 8 == 0x05)
30		return -1;
31	/* Ignore key up event */
32	if ((usage->hid & HID_USAGE) >> 8 == 0x06)
33		return -1;
34
35	switch (usage->hid & HID_USAGE) {
36	/* Ignore configuration saved event */
37	case 0x0401: return -1;
38	/* Ignore reset event */
39	case 0x0402: return -1;
40	}
41	return 0;
42}
43
44#define REP_DSC_SIZE 236
45#define USAGE_MAX_INDEX 59
46
47static const __u8 *evision_report_fixup(struct hid_device *hdev, __u8 *rdesc,
48		unsigned int *rsize)
49{
50	if (hdev->product == USB_DEVICE_ID_EV_TELINK_RECEIVER &&
51	    *rsize == REP_DSC_SIZE && rdesc[USAGE_MAX_INDEX] == 0x29 &&
52	    rdesc[USAGE_MAX_INDEX + 1] == 3) {
53		hid_info(hdev, "fixing EVision:TeLink Receiver report descriptor\n");
54		rdesc[USAGE_MAX_INDEX + 1] = 5; // change usage max from 3 to 5
55	}
56	return rdesc;
57}
58
59static const struct hid_device_id evision_devices[] = {
60	{ HID_USB_DEVICE(USB_VENDOR_ID_EVISION, USB_DEVICE_ID_EVISION_ICL01) },
61	{ HID_USB_DEVICE(USB_VENDOR_ID_EVISION, USB_DEVICE_ID_EV_TELINK_RECEIVER) },
62	{ }
63};
64MODULE_DEVICE_TABLE(hid, evision_devices);
65
66static struct hid_driver evision_driver = {
67	.name = "evision",
68	.id_table = evision_devices,
69	.input_mapping = evision_input_mapping,
70	.report_fixup = evision_report_fixup,
71};
72module_hid_driver(evision_driver);
73
74MODULE_DESCRIPTION("HID driver for EVision devices");
75MODULE_LICENSE("GPL");