// SPDX-License-Identifier: GPL-2.0-or-later
/*
* HID driver for Holtek keyboard
* Copyright (c) 2012 Tom Harwood
*/
/*
*/
#include <linux/device.h>
#include <linux/hid.h>
#include <linux/module.h>
#include <linux/usb.h>
#include "hid-ids.h"
#include "usbhid/usbhid.h"
/* Holtek based keyboards (USB ID 04d9:a055) have the following issues:
* - The report descriptor specifies an excessively large number of consumer
* usages (2^15), which is more than HID_MAX_USAGES. This prevents proper
* parsing of the report descriptor.
* - The report descriptor reports on caps/scroll/num lock key presses, but
* doesn't have an LED output usage block.
*
* The replacement descriptor below fixes the number of consumer usages,
* and provides an LED output usage block. LED output events are redirected
* to the boot interface.
*/
static __u8 holtek_kbd_rdesc_fixed[] = {
/* Original report descriptor, with reduced number of consumer usages */
0x05, 0x01, /* Usage Page (Desktop), */
0x09, 0x80, /* Usage (Sys Control), */
0xA1, 0x01, /* Collection (Application), */
0x85, 0x01, /* Report ID (1), */
0x19, 0x81, /* Usage Minimum (Sys Power Down), */
0x29, 0x83, /* Usage Maximum (Sys Wake Up), */
0x15, 0x00, /* Logical Minimum (0), */
0x25, 0x01, /* Logical Maximum (1), */
0x95, 0x03, /* Report Count (3), */
0x75, 0x01, /* Report Size (1), */
0x81, 0x02, /* Input (Variable), */
0x95, 0x01, /* Report Count (1), */
0x75, 0x05, /* Report Size (5), */
0x81, 0x01, /* Input (Constant), */
0xC0, /* End Collection, */
0x05, 0x0C, /* Usage Page (Consumer), */
0x09, 0x01, /* Usage (Consumer Control), */
0xA1, 0x01, /* Collection (Application), */
0x85, 0x02, /* Report ID (2), */
0x19, 0x00, /* Usage Minimum (00h), */
0x2A, 0xFF, 0x2F, /* Usage Maximum (0x2FFF), previously 0x7FFF */
0x15, 0x00, /* Logical Minimum (0), */
0x26, 0xFF, 0x2F, /* Logical Maximum (0x2FFF),previously 0x7FFF*/
0x95, 0x01, /* Report Count (1), */
0x75, 0x10, /* Report Size (16), */
0x81, 0x00, /* Input, */
0xC0, /* End Collection, */
0x05, 0x01, /* Usage Page (Desktop), */
0x09, 0x06, /* Usage (Keyboard), */
0xA1, 0x01, /* Collection (Application), */
0x85, 0x03, /* Report ID (3), */
0x95, 0x38, /* Report Count (56), */
0x75, 0x01, /* Report Size (1), */
0x15, 0x00, /* Logical Minimum (0), */
0x25, 0x01, /* Logical Maximum (1), */
0x05, 0x07, /* Usage Page (Keyboard), */
0x19, 0xE0, /* Usage Minimum (KB Leftcontrol), */
0x29, 0xE7, /* Usage Maximum (KB Right GUI), */
0x19, 0x00, /* Usage Minimum (None), */
0x29, 0x2F, /* Usage Maximum (KB Lboxbracket And Lbrace),*/
0x81, 0x02, /* Input (Variable), */
0xC0, /* End Collection, */
0x05, 0x01, /* Usage Page (Desktop), */
0x09, 0x06, /* Usage (Keyboard), */
0xA1, 0x01, /* Collection (Application), */
0x85, 0x04, /* Report ID (4), */
0x95, 0x38, /* Report Count (56), */
0x75, 0x01, /* Report Size (1), */
0x15, 0x00, /* Logical Minimum (0), */
0x25, 0x01, /* Logical Maximum (1), */
0x05, 0x07, /* Usage Page (Keyboard), */
0x19, 0x30, /* Usage Minimum (KB Rboxbracket And Rbrace),*/
0x29, 0x67, /* Usage Maximum (KP Equals), */
0x81, 0x02, /* Input (Variable), */
0xC0, /* End Collection */
/* LED usage for the boot protocol interface */
0x05, 0x01, /* Usage Page (Desktop), */
0x09, 0x06, /* Usage (Keyboard), */
0xA1, 0x01, /* Collection (Application), */
0x05, 0x08, /* Usage Page (LED), */
0x19, 0x01, /* Usage Minimum (01h), */
0x29, 0x03, /* Usage Maximum (03h), */
0x15, 0x00, /* Logical Minimum (0), */
0x25, 0x01, /* Logical Maximum (1), */
0x75, 0x01, /* Report Size (1), */
0x95, 0x03, /* Report Count (3), */
0x91, 0x02, /* Output (Variable), */
0x95, 0x05, /* Report Count (5), */
0x91, 0x01, /* Output (Constant), */
0xC0, /* End Collection */
};
static __u8 *holtek_kbd_report_fixup(struct hid_device *hdev, __u8 *rdesc,
unsigned int *rsize)
{
struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
if (intf->cur_altsetting->desc.bInterfaceNumber == 1) {
rdesc = holtek_kbd_rdesc_fixed;
*rsize = sizeof(holtek_kbd_rdesc_fixed);
}
return rdesc;
}
static int holtek_kbd_input_event(struct input_dev *dev, unsigned int type,
unsigned int code,
int value)
{
struct hid_device *hid = input_get_drvdata(dev);
struct usb_device *usb_dev = hid_to_usb_dev(hid);
/* Locate the boot interface, to receive the LED change events */
struct usb_interface *boot_interface = usb_ifnum_to_if(usb_dev, 0);
struct hid_device *boot_hid;
struct hid_input *boot_hid_input;
if (unlikely(boot_interface == NULL))
return -ENODEV;
boot_hid = usb_get_intfdata(boot_interface);
boot_hid_input = list_first_entry(&boot_hid->inputs,
struct hid_input, list);
return boot_hid_input->input->event(boot_hid_input->input, type, code,
value);
}
static int holtek_kbd_probe(struct hid_device *hdev,
const struct hid_device_id *id)
{
struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
int ret = hid_parse(hdev);
if (!ret)
ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
if (!ret && intf->cur_altsetting->desc.bInterfaceNumber == 1) {
struct hid_input *hidinput;
list_for_each_entry(hidinput, &hdev->inputs, list) {
hidinput->input->event = holtek_kbd_input_event;
}
}
return ret;
}
static const struct hid_device_id holtek_kbd_devices[] = {
{ HID_USB_DEVICE(USB_VENDOR_ID_HOLTEK_ALT,
USB_DEVICE_ID_HOLTEK_ALT_KEYBOARD) },
{ }
};
MODULE_DEVICE_TABLE(hid, holtek_kbd_devices);
static struct hid_driver holtek_kbd_driver = {
.name = "holtek_kbd",
.id_table = holtek_kbd_devices,
.report_fixup = holtek_kbd_report_fixup,
.probe = holtek_kbd_probe
};
module_hid_driver(holtek_kbd_driver);
MODULE_LICENSE("GPL");
