1/*
2 * HID driver for Holtek keyboard
3 * Copyright (c) 2012 Tom Harwood
4*/
5
6/*
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the Free
9 * Software Foundation; either version 2 of the License, or (at your option)
10 * any later version.
11 */
12
13#include <linux/device.h>
14#include <linux/hid.h>
15#include <linux/module.h>
16#include <linux/usb.h>
17
18#include "hid-ids.h"
19#include "usbhid/usbhid.h"
20
21/* Holtek based keyboards (USB ID 04d9:a055) have the following issues:
22 * - The report descriptor specifies an excessively large number of consumer
23 * usages (2^15), which is more than HID_MAX_USAGES. This prevents proper
24 * parsing of the report descriptor.
25 * - The report descriptor reports on caps/scroll/num lock key presses, but
26 * doesn't have an LED output usage block.
27 *
28 * The replacement descriptor below fixes the number of consumer usages,
29 * and provides an LED output usage block. LED output events are redirected
30 * to the boot interface.
31 */
32
33static __u8 holtek_kbd_rdesc_fixed[] = {
34 /* Original report descriptor, with reduced number of consumer usages */
35 0x05, 0x01, /* Usage Page (Desktop), */
36 0x09, 0x80, /* Usage (Sys Control), */
37 0xA1, 0x01, /* Collection (Application), */
38 0x85, 0x01, /* Report ID (1), */
39 0x19, 0x81, /* Usage Minimum (Sys Power Down), */
40 0x29, 0x83, /* Usage Maximum (Sys Wake Up), */
41 0x15, 0x00, /* Logical Minimum (0), */
42 0x25, 0x01, /* Logical Maximum (1), */
43 0x95, 0x03, /* Report Count (3), */
44 0x75, 0x01, /* Report Size (1), */
45 0x81, 0x02, /* Input (Variable), */
46 0x95, 0x01, /* Report Count (1), */
47 0x75, 0x05, /* Report Size (5), */
48 0x81, 0x01, /* Input (Constant), */
49 0xC0, /* End Collection, */
50 0x05, 0x0C, /* Usage Page (Consumer), */
51 0x09, 0x01, /* Usage (Consumer Control), */
52 0xA1, 0x01, /* Collection (Application), */
53 0x85, 0x02, /* Report ID (2), */
54 0x19, 0x00, /* Usage Minimum (00h), */
55 0x2A, 0xFF, 0x2F, /* Usage Maximum (0x2FFF), previously 0x7FFF */
56 0x15, 0x00, /* Logical Minimum (0), */
57 0x26, 0xFF, 0x2F, /* Logical Maximum (0x2FFF),previously 0x7FFF*/
58 0x95, 0x01, /* Report Count (1), */
59 0x75, 0x10, /* Report Size (16), */
60 0x81, 0x00, /* Input, */
61 0xC0, /* End Collection, */
62 0x05, 0x01, /* Usage Page (Desktop), */
63 0x09, 0x06, /* Usage (Keyboard), */
64 0xA1, 0x01, /* Collection (Application), */
65 0x85, 0x03, /* Report ID (3), */
66 0x95, 0x38, /* Report Count (56), */
67 0x75, 0x01, /* Report Size (1), */
68 0x15, 0x00, /* Logical Minimum (0), */
69 0x25, 0x01, /* Logical Maximum (1), */
70 0x05, 0x07, /* Usage Page (Keyboard), */
71 0x19, 0xE0, /* Usage Minimum (KB Leftcontrol), */
72 0x29, 0xE7, /* Usage Maximum (KB Right GUI), */
73 0x19, 0x00, /* Usage Minimum (None), */
74 0x29, 0x2F, /* Usage Maximum (KB Lboxbracket And Lbrace),*/
75 0x81, 0x02, /* Input (Variable), */
76 0xC0, /* End Collection, */
77 0x05, 0x01, /* Usage Page (Desktop), */
78 0x09, 0x06, /* Usage (Keyboard), */
79 0xA1, 0x01, /* Collection (Application), */
80 0x85, 0x04, /* Report ID (4), */
81 0x95, 0x38, /* Report Count (56), */
82 0x75, 0x01, /* Report Size (1), */
83 0x15, 0x00, /* Logical Minimum (0), */
84 0x25, 0x01, /* Logical Maximum (1), */
85 0x05, 0x07, /* Usage Page (Keyboard), */
86 0x19, 0x30, /* Usage Minimum (KB Rboxbracket And Rbrace),*/
87 0x29, 0x67, /* Usage Maximum (KP Equals), */
88 0x81, 0x02, /* Input (Variable), */
89 0xC0, /* End Collection */
90
91 /* LED usage for the boot protocol interface */
92 0x05, 0x01, /* Usage Page (Desktop), */
93 0x09, 0x06, /* Usage (Keyboard), */
94 0xA1, 0x01, /* Collection (Application), */
95 0x05, 0x08, /* Usage Page (LED), */
96 0x19, 0x01, /* Usage Minimum (01h), */
97 0x29, 0x03, /* Usage Maximum (03h), */
98 0x15, 0x00, /* Logical Minimum (0), */
99 0x25, 0x01, /* Logical Maximum (1), */
100 0x75, 0x01, /* Report Size (1), */
101 0x95, 0x03, /* Report Count (3), */
102 0x91, 0x02, /* Output (Variable), */
103 0x95, 0x05, /* Report Count (5), */
104 0x91, 0x01, /* Output (Constant), */
105 0xC0, /* End Collection */
106};
107
108static __u8 *holtek_kbd_report_fixup(struct hid_device *hdev, __u8 *rdesc,
109 unsigned int *rsize)
110{
111 struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
112
113 if (intf->cur_altsetting->desc.bInterfaceNumber == 1) {
114 rdesc = holtek_kbd_rdesc_fixed;
115 *rsize = sizeof(holtek_kbd_rdesc_fixed);
116 }
117 return rdesc;
118}
119
120static int holtek_kbd_input_event(struct input_dev *dev, unsigned int type,
121 unsigned int code,
122 int value)
123{
124 struct hid_device *hid = input_get_drvdata(dev);
125 struct usb_device *usb_dev = hid_to_usb_dev(hid);
126
127 /* Locate the boot interface, to receive the LED change events */
128 struct usb_interface *boot_interface = usb_ifnum_to_if(usb_dev, 0);
129
130 struct hid_device *boot_hid = usb_get_intfdata(boot_interface);
131 struct hid_input *boot_hid_input = list_first_entry(&boot_hid->inputs,
132 struct hid_input, list);
133
134 return boot_hid_input->input->event(boot_hid_input->input, type, code,
135 value);
136}
137
138static int holtek_kbd_probe(struct hid_device *hdev,
139 const struct hid_device_id *id)
140{
141 struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
142 int ret = hid_parse(hdev);
143
144 if (!ret)
145 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
146
147 if (!ret && intf->cur_altsetting->desc.bInterfaceNumber == 1) {
148 struct hid_input *hidinput;
149 list_for_each_entry(hidinput, &hdev->inputs, list) {
150 hidinput->input->event = holtek_kbd_input_event;
151 }
152 }
153
154 return ret;
155}
156
157static const struct hid_device_id holtek_kbd_devices[] = {
158 { HID_USB_DEVICE(USB_VENDOR_ID_HOLTEK_ALT,
159 USB_DEVICE_ID_HOLTEK_ALT_KEYBOARD) },
160 { }
161};
162MODULE_DEVICE_TABLE(hid, holtek_kbd_devices);
163
164static struct hid_driver holtek_kbd_driver = {
165 .name = "holtek_kbd",
166 .id_table = holtek_kbd_devices,
167 .report_fixup = holtek_kbd_report_fixup,
168 .probe = holtek_kbd_probe
169};
170module_hid_driver(holtek_kbd_driver);
171
172MODULE_LICENSE("GPL");
173