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

// 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[] = …;

static __u8 *holtek_kbd_report_fixup(struct hid_device *hdev, __u8 *rdesc,
		unsigned int *rsize)
{ … }

static int holtek_kbd_input_event(struct input_dev *dev, unsigned int type,
		unsigned int code,
		int value)
{ … }

static int holtek_kbd_probe(struct hid_device *hdev,
		const struct hid_device_id *id)
{ … }

static const struct hid_device_id holtek_kbd_devices[] = …;
MODULE_DEVICE_TABLE(hid, holtek_kbd_devices);

static struct hid_driver holtek_kbd_driver = …;
module_hid_driver(…) …;

MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;