1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * HID driver for primax and similar keyboards with in-band modifiers
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright 2011 Google Inc. All Rights Reserved
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun * Author:
8*4882a593Smuzhiyun * Terry Lambert <tlambert@google.com>
9*4882a593Smuzhiyun */
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun #include <linux/device.h>
12*4882a593Smuzhiyun #include <linux/hid.h>
13*4882a593Smuzhiyun #include <linux/module.h>
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun #include "hid-ids.h"
16*4882a593Smuzhiyun
px_raw_event(struct hid_device * hid,struct hid_report * report,u8 * data,int size)17*4882a593Smuzhiyun static int px_raw_event(struct hid_device *hid, struct hid_report *report,
18*4882a593Smuzhiyun u8 *data, int size)
19*4882a593Smuzhiyun {
20*4882a593Smuzhiyun int idx = size;
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun switch (report->id) {
23*4882a593Smuzhiyun case 0: /* keyboard input */
24*4882a593Smuzhiyun /*
25*4882a593Smuzhiyun * Convert in-band modifier key values into out of band
26*4882a593Smuzhiyun * modifier bits and pull the key strokes from the report.
27*4882a593Smuzhiyun * Thus a report data set which looked like:
28*4882a593Smuzhiyun *
29*4882a593Smuzhiyun * [00][00][E0][30][00][00][00][00]
30*4882a593Smuzhiyun * (no modifier bits + "Left Shift" key + "1" key)
31*4882a593Smuzhiyun *
32*4882a593Smuzhiyun * Would be converted to:
33*4882a593Smuzhiyun *
34*4882a593Smuzhiyun * [01][00][00][30][00][00][00][00]
35*4882a593Smuzhiyun * (Left Shift modifier bit + "1" key)
36*4882a593Smuzhiyun *
37*4882a593Smuzhiyun * As long as it's in the size range, the upper level
38*4882a593Smuzhiyun * drivers don't particularly care if there are in-band
39*4882a593Smuzhiyun * 0-valued keys, so they don't stop parsing.
40*4882a593Smuzhiyun */
41*4882a593Smuzhiyun while (--idx > 1) {
42*4882a593Smuzhiyun if (data[idx] < 0xE0 || data[idx] > 0xE7)
43*4882a593Smuzhiyun continue;
44*4882a593Smuzhiyun data[0] |= (1 << (data[idx] - 0xE0));
45*4882a593Smuzhiyun data[idx] = 0;
46*4882a593Smuzhiyun }
47*4882a593Smuzhiyun hid_report_raw_event(hid, HID_INPUT_REPORT, data, size, 0);
48*4882a593Smuzhiyun return 1;
49*4882a593Smuzhiyun
50*4882a593Smuzhiyun default: /* unknown report */
51*4882a593Smuzhiyun /* Unknown report type; pass upstream */
52*4882a593Smuzhiyun hid_info(hid, "unknown report type %d\n", report->id);
53*4882a593Smuzhiyun break;
54*4882a593Smuzhiyun }
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun return 0;
57*4882a593Smuzhiyun }
58*4882a593Smuzhiyun
59*4882a593Smuzhiyun static const struct hid_device_id px_devices[] = {
60*4882a593Smuzhiyun { HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_KEYBOARD) },
61*4882a593Smuzhiyun { }
62*4882a593Smuzhiyun };
63*4882a593Smuzhiyun MODULE_DEVICE_TABLE(hid, px_devices);
64*4882a593Smuzhiyun
65*4882a593Smuzhiyun static struct hid_driver px_driver = {
66*4882a593Smuzhiyun .name = "primax",
67*4882a593Smuzhiyun .id_table = px_devices,
68*4882a593Smuzhiyun .raw_event = px_raw_event,
69*4882a593Smuzhiyun };
70*4882a593Smuzhiyun module_hid_driver(px_driver);
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun MODULE_AUTHOR("Terry Lambert <tlambert@google.com>");
73*4882a593Smuzhiyun MODULE_LICENSE("GPL");
74