1/*
2 * HID driver for primax and similar keyboards with in-band modifiers
3 *
4 * Copyright 2011 Google Inc. All Rights Reserved
5 *
6 * Author:
7 * Terry Lambert <tlambert@google.com>
8 *
9 * This software is licensed under the terms of the GNU General Public
10 * License version 2, as published by the Free Software Foundation, and
11 * may be copied, distributed, and modified under those terms.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 */
18
19#include <linux/device.h>
20#include <linux/hid.h>
21#include <linux/module.h>
22
23#include "hid-ids.h"
24
25static int px_raw_event(struct hid_device *hid, struct hid_report *report,
26 u8 *data, int size)
27{
28 int idx = size;
29
30 switch (report->id) {
31 case 0: /* keyboard input */
32 /*
33 * Convert in-band modifier key values into out of band
34 * modifier bits and pull the key strokes from the report.
35 * Thus a report data set which looked like:
36 *
37 * [00][00][E0][30][00][00][00][00]
38 * (no modifier bits + "Left Shift" key + "1" key)
39 *
40 * Would be converted to:
41 *
42 * [01][00][00][30][00][00][00][00]
43 * (Left Shift modifier bit + "1" key)
44 *
45 * As long as it's in the size range, the upper level
46 * drivers don't particularly care if there are in-band
47 * 0-valued keys, so they don't stop parsing.
48 */
49 while (--idx > 1) {
50 if (data[idx] < 0xE0 || data[idx] > 0xE7)
51 continue;
52 data[0] |= (1 << (data[idx] - 0xE0));
53 data[idx] = 0;
54 }
55 hid_report_raw_event(hid, HID_INPUT_REPORT, data, size, 0);
56 return 1;
57
58 default: /* unknown report */
59 /* Unknown report type; pass upstream */
60 hid_info(hid, "unknown report type %d\n", report->id);
61 break;
62 }
63
64 return 0;
65}
66
67static const struct hid_device_id px_devices[] = {
68 { HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_KEYBOARD) },
69 { }
70};
71MODULE_DEVICE_TABLE(hid, px_devices);
72
73static struct hid_driver px_driver = {
74 .name = "primax",
75 .id_table = px_devices,
76 .raw_event = px_raw_event,
77};
78module_hid_driver(px_driver);
79
80MODULE_AUTHOR("Terry Lambert <tlambert@google.com>");
81MODULE_LICENSE("GPL");
82