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 30 static __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 }; 104 105 static __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 } 116 117 static 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 } 139 140 static int holtek_kbd_probe(struct hid_device *hdev, 141 const struct hid_device_id *id) 142 { 143 struct usb_interface *intf; 144 int ret; 145 146 if (!hid_is_usb(hdev)) 147 return -EINVAL; 148 149 ret = hid_parse(hdev); 150 if (!ret) 151 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT); 152 153 intf = to_usb_interface(hdev->dev.parent); 154 if (!ret && intf->cur_altsetting->desc.bInterfaceNumber == 1) { 155 struct hid_input *hidinput; 156 list_for_each_entry(hidinput, &hdev->inputs, list) { 157 hidinput->input->event = holtek_kbd_input_event; 158 } 159 } 160 161 return ret; 162 } 163 164 static const struct hid_device_id holtek_kbd_devices[] = { 165 { HID_USB_DEVICE(USB_VENDOR_ID_HOLTEK_ALT, 166 USB_DEVICE_ID_HOLTEK_ALT_KEYBOARD) }, 167 { } 168 }; 169 MODULE_DEVICE_TABLE(hid, holtek_kbd_devices); 170 171 static struct hid_driver holtek_kbd_driver = { 172 .name = "holtek_kbd", 173 .id_table = holtek_kbd_devices, 174 .report_fixup = holtek_kbd_report_fixup, 175 .probe = holtek_kbd_probe 176 }; 177 module_hid_driver(holtek_kbd_driver); 178 179 MODULE_LICENSE("GPL"); 180