drivers/hid/hid-holtek-kbd.c

   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
  33 static __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
 108 static __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
 120 static 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
 138 static 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
 157 static 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 };
 162 MODULE_DEVICE_TABLE(hid, holtek_kbd_devices);
 163
 164 static 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 };
 170 module_hid_driver(holtek_kbd_driver);
 171
 172 MODULE_LICENSE("GPL");