LXR linux/drivers/hid/hid-holtek-kbd.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * HID driver for Holtek keyboard
   4 * Copyright (c) 2012 Tom Harwood
   5*/
   6
   7/*
   8 */
   9
  10#include <linux/device.h>
  11#include <linux/hid.h>
  12#include <linux/module.h>
  13#include <linux/usb.h>
  14
  15#include "hid-ids.h"
  16#include "usbhid/usbhid.h"
  17
  18/* Holtek based keyboards (USB ID 04d9:a055) have the following issues:
  19 * - The report descriptor specifies an excessively large number of consumer
  20 *   usages (2^15), which is more than HID_MAX_USAGES. This prevents proper
  21 *   parsing of the report descriptor.
  22 * - The report descriptor reports on caps/scroll/num lock key presses, but
  23 *   doesn't have an LED output usage block.
  24 *
  25 * The replacement descriptor below fixes the number of consumer usages,
  26 * and provides an LED output usage block. LED output events are redirected
  27 * to the boot interface.
  28 */
  29
  30static __u8 holtek_kbd_rdesc_fixed[] = {
  31        /* Original report descriptor, with reduced number of consumer usages */
  32        0x05, 0x01,         /*  Usage Page (Desktop),                         */
  33        0x09, 0x80,         /*  Usage (Sys Control),                          */
  34        0xA1, 0x01,         /*  Collection (Application),                     */
  35        0x85, 0x01,         /*      Report ID (1),                            */
  36        0x19, 0x81,         /*      Usage Minimum (Sys Power Down),           */
  37        0x29, 0x83,         /*      Usage Maximum (Sys Wake Up),              */
  38        0x15, 0x00,         /*      Logical Minimum (0),                      */
  39        0x25, 0x01,         /*      Logical Maximum (1),                      */
  40        0x95, 0x03,         /*      Report Count (3),                         */
  41        0x75, 0x01,         /*      Report Size (1),                          */
  42        0x81, 0x02,         /*      Input (Variable),                         */
  43        0x95, 0x01,         /*      Report Count (1),                         */
  44        0x75, 0x05,         /*      Report Size (5),                          */
  45        0x81, 0x01,         /*      Input (Constant),                         */
  46        0xC0,               /*  End Collection,                               */
  47        0x05, 0x0C,         /*  Usage Page (Consumer),                        */
  48        0x09, 0x01,         /*  Usage (Consumer Control),                     */
  49        0xA1, 0x01,         /*  Collection (Application),                     */
  50        0x85, 0x02,         /*      Report ID (2),                            */
  51        0x19, 0x00,         /*      Usage Minimum (00h),                      */
  52        0x2A, 0xFF, 0x2F,   /*      Usage Maximum (0x2FFF), previously 0x7FFF */
  53        0x15, 0x00,         /*      Logical Minimum (0),                      */
  54        0x26, 0xFF, 0x2F,   /*      Logical Maximum (0x2FFF),previously 0x7FFF*/
  55        0x95, 0x01,         /*      Report Count (1),                         */
  56        0x75, 0x10,         /*      Report Size (16),                         */
  57        0x81, 0x00,         /*      Input,                                    */
  58        0xC0,               /*  End Collection,                               */
  59        0x05, 0x01,         /*  Usage Page (Desktop),                         */
  60        0x09, 0x06,         /*  Usage (Keyboard),                             */
  61        0xA1, 0x01,         /*  Collection (Application),                     */
  62        0x85, 0x03,         /*      Report ID (3),                            */
  63        0x95, 0x38,         /*      Report Count (56),                        */
  64        0x75, 0x01,         /*      Report Size (1),                          */
  65        0x15, 0x00,         /*      Logical Minimum (0),                      */
  66        0x25, 0x01,         /*      Logical Maximum (1),                      */
  67        0x05, 0x07,         /*      Usage Page (Keyboard),                    */
  68        0x19, 0xE0,         /*      Usage Minimum (KB Leftcontrol),           */
  69        0x29, 0xE7,         /*      Usage Maximum (KB Right GUI),             */
  70        0x19, 0x00,         /*      Usage Minimum (None),                     */
  71        0x29, 0x2F,         /*      Usage Maximum (KB Lboxbracket And Lbrace),*/
  72        0x81, 0x02,         /*      Input (Variable),                         */
  73        0xC0,               /*  End Collection,                               */
  74        0x05, 0x01,         /*  Usage Page (Desktop),                         */
  75        0x09, 0x06,         /*  Usage (Keyboard),                             */
  76        0xA1, 0x01,         /*  Collection (Application),                     */
  77        0x85, 0x04,         /*      Report ID (4),                            */
  78        0x95, 0x38,         /*      Report Count (56),                        */
  79        0x75, 0x01,         /*      Report Size (1),                          */
  80        0x15, 0x00,         /*      Logical Minimum (0),                      */
  81        0x25, 0x01,         /*      Logical Maximum (1),                      */
  82        0x05, 0x07,         /*      Usage Page (Keyboard),                    */
  83        0x19, 0x30,         /*      Usage Minimum (KB Rboxbracket And Rbrace),*/
  84        0x29, 0x67,         /*      Usage Maximum (KP Equals),                */
  85        0x81, 0x02,         /*      Input (Variable),                         */
  86        0xC0,               /*  End Collection                                */
  87
  88        /* LED usage for the boot protocol interface */
  89        0x05, 0x01,         /*  Usage Page (Desktop),                         */
  90        0x09, 0x06,         /*  Usage (Keyboard),                             */
  91        0xA1, 0x01,         /*  Collection (Application),                     */
  92        0x05, 0x08,         /*      Usage Page (LED),                         */
  93        0x19, 0x01,         /*      Usage Minimum (01h),                      */
  94        0x29, 0x03,         /*      Usage Maximum (03h),                      */
  95        0x15, 0x00,         /*      Logical Minimum (0),                      */
  96        0x25, 0x01,         /*      Logical Maximum (1),                      */
  97        0x75, 0x01,         /*      Report Size (1),                          */
  98        0x95, 0x03,         /*      Report Count (3),                         */
  99        0x91, 0x02,         /*      Output (Variable),                        */
 100        0x95, 0x05,         /*      Report Count (5),                         */
 101        0x91, 0x01,         /*      Output (Constant),                        */
 102        0xC0,               /*  End Collection                                */
 103};
 104
 105static __u8 *holtek_kbd_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 106                unsigned int *rsize)
 107{
 108        struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
 109
 110        if (intf->cur_altsetting->desc.bInterfaceNumber == 1) {
 111                rdesc = holtek_kbd_rdesc_fixed;
 112                *rsize = sizeof(holtek_kbd_rdesc_fixed);
 113        }
 114        return rdesc;
 115}
 116
 117static int holtek_kbd_input_event(struct input_dev *dev, unsigned int type,
 118                unsigned int code,
 119                int value)
 120{
 121        struct hid_device *hid = input_get_drvdata(dev);
 122        struct usb_device *usb_dev = hid_to_usb_dev(hid);
 123
 124        /* Locate the boot interface, to receive the LED change events */
 125        struct usb_interface *boot_interface = usb_ifnum_to_if(usb_dev, 0);
 126        struct hid_device *boot_hid;
 127        struct hid_input *boot_hid_input;
 128
 129        if (unlikely(boot_interface == NULL))
 130                return -ENODEV;
 131
 132        boot_hid = usb_get_intfdata(boot_interface);
 133        boot_hid_input = list_first_entry(&boot_hid->inputs,
 134                struct hid_input, list);
 135
 136        return boot_hid_input->input->event(boot_hid_input->input, type, code,
 137                        value);
 138}
 139
 140static int holtek_kbd_probe(struct hid_device *hdev,
 141                const struct hid_device_id *id)
 142{
 143        struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
 144        int ret = hid_parse(hdev);
 145
 146        if (!ret)
 147                ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 148
 149        if (!ret && intf->cur_altsetting->desc.bInterfaceNumber == 1) {
 150                struct hid_input *hidinput;
 151                list_for_each_entry(hidinput, &hdev->inputs, list) {
 152                        hidinput->input->event = holtek_kbd_input_event;
 153                }
 154        }
 155
 156        return ret;
 157}
 158
 159static const struct hid_device_id holtek_kbd_devices[] = {
 160        { HID_USB_DEVICE(USB_VENDOR_ID_HOLTEK_ALT,
 161                        USB_DEVICE_ID_HOLTEK_ALT_KEYBOARD) },
 162        { }
 163};
 164MODULE_DEVICE_TABLE(hid, holtek_kbd_devices);
 165
 166static struct hid_driver holtek_kbd_driver = {
 167        .name = "holtek_kbd",
 168        .id_table = holtek_kbd_devices,
 169        .report_fixup = holtek_kbd_report_fixup,
 170        .probe = holtek_kbd_probe
 171};
 172module_hid_driver(holtek_kbd_driver);
 173
 174MODULE_LICENSE("GPL");
 175