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