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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * HID driver for Holtek keyboard4 * Copyright (c) 2012 Tom Harwood5*/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 consumer20 * usages (2^15), which is more than HID_MAX_USAGES. This prevents proper21 * parsing of the report descriptor.22 * - The report descriptor reports on caps/scroll/num lock key presses, but23 * 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 redirected27 * to the boot interface.28 */29 30static const __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 const __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 *rsize = sizeof(holtek_kbd_rdesc_fixed);112 return 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 if (list_empty(&boot_hid->inputs)) {134 hid_err(hid, "no inputs found\n");135 return -ENODEV;136 }137 boot_hid_input = list_first_entry(&boot_hid->inputs,138 struct hid_input, list);139 140 return boot_hid_input->input->event(boot_hid_input->input, type, code,141 value);142}143 144static int holtek_kbd_probe(struct hid_device *hdev,145 const struct hid_device_id *id)146{147 struct usb_interface *intf;148 int ret;149 150 if (!hid_is_usb(hdev))151 return -EINVAL;152 153 ret = hid_parse(hdev);154 if (!ret)155 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);156 157 intf = to_usb_interface(hdev->dev.parent);158 if (!ret && intf->cur_altsetting->desc.bInterfaceNumber == 1) {159 struct hid_input *hidinput;160 list_for_each_entry(hidinput, &hdev->inputs, list) {161 hidinput->input->event = holtek_kbd_input_event;162 }163 }164 165 return ret;166}167 168static const struct hid_device_id holtek_kbd_devices[] = {169 { HID_USB_DEVICE(USB_VENDOR_ID_HOLTEK_ALT,170 USB_DEVICE_ID_HOLTEK_ALT_KEYBOARD) },171 { }172};173MODULE_DEVICE_TABLE(hid, holtek_kbd_devices);174 175static struct hid_driver holtek_kbd_driver = {176 .name = "holtek_kbd",177 .id_table = holtek_kbd_devices,178 .report_fixup = holtek_kbd_report_fixup,179 .probe = holtek_kbd_probe180};181module_hid_driver(holtek_kbd_driver);182 183MODULE_DESCRIPTION("HID driver for Holtek keyboard");184MODULE_LICENSE("GPL");185