![Sudip Mukherjee](/assets/img/avatar_default.png)
parkbd_parport_cb is a local uninitialized structure and the member
function pointers will be pointing to arbitrary locations unless they
are cleared.
Fixes: 33ca8ab97c
("Input: parkbd - use parallel port device model")
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
240 lines
5.6 KiB
C
240 lines
5.6 KiB
C
/*
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* Parallel port to Keyboard port adapter driver for Linux
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*
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* Copyright (c) 1999-2004 Vojtech Pavlik
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*/
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/*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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/*
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* To connect an AT or XT keyboard to the parallel port, a fairly simple adapter
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* can be made:
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*
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* Parallel port Keyboard port
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*
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* +5V --------------------- +5V (4)
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*
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* ______
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* +5V -------|______|--.
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* |
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* ACK (10) ------------|
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* |--- KBD CLOCK (5)
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* STROBE (1) ---|<|----'
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*
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* ______
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* +5V -------|______|--.
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* |
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* BUSY (11) -----------|
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* |--- KBD DATA (1)
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* AUTOFD (14) --|<|----'
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*
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* GND (18-25) ------------- GND (3)
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*
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* The diodes can be fairly any type, and the resistors should be somewhere
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* around 5 kOhm, but the adapter will likely work without the resistors,
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* too.
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*
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* The +5V source can be taken either from USB, from mouse or keyboard ports,
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* or from a joystick port. Unfortunately, the parallel port of a PC doesn't
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* have a +5V pin, and feeding the keyboard from signal pins is out of question
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* with 300 mA power reqirement of a typical AT keyboard.
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*/
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#include <linux/module.h>
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#include <linux/parport.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/serio.h>
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MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
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MODULE_DESCRIPTION("Parallel port to Keyboard port adapter driver");
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MODULE_LICENSE("GPL");
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static unsigned int parkbd_pp_no;
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module_param_named(port, parkbd_pp_no, int, 0);
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MODULE_PARM_DESC(port, "Parallel port the adapter is connected to (default is 0)");
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static unsigned int parkbd_mode = SERIO_8042;
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module_param_named(mode, parkbd_mode, uint, 0);
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MODULE_PARM_DESC(mode, "Mode of operation: XT = 0/AT = 1 (default)");
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#define PARKBD_CLOCK 0x01 /* Strobe & Ack */
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#define PARKBD_DATA 0x02 /* AutoFd & Busy */
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static int parkbd_buffer;
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static int parkbd_counter;
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static unsigned long parkbd_last;
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static int parkbd_writing;
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static unsigned long parkbd_start;
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static struct pardevice *parkbd_dev;
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static struct serio *parkbd_port;
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static int parkbd_readlines(void)
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{
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return (parport_read_status(parkbd_dev->port) >> 6) ^ 2;
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}
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static void parkbd_writelines(int data)
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{
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parport_write_control(parkbd_dev->port, (~data & 3) | 0x10);
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}
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static int parkbd_write(struct serio *port, unsigned char c)
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{
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unsigned char p;
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if (!parkbd_mode) return -1;
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p = c ^ (c >> 4);
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p = p ^ (p >> 2);
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p = p ^ (p >> 1);
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parkbd_counter = 0;
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parkbd_writing = 1;
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parkbd_buffer = c | (((int) (~p & 1)) << 8) | 0x600;
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parkbd_writelines(2);
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return 0;
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}
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static void parkbd_interrupt(void *dev_id)
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{
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if (parkbd_writing) {
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if (parkbd_counter && ((parkbd_counter == 11) || time_after(jiffies, parkbd_last + HZ/100))) {
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parkbd_counter = 0;
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parkbd_buffer = 0;
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parkbd_writing = 0;
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parkbd_writelines(3);
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return;
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}
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parkbd_writelines(((parkbd_buffer >> parkbd_counter++) & 1) | 2);
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if (parkbd_counter == 11) {
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parkbd_counter = 0;
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parkbd_buffer = 0;
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parkbd_writing = 0;
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parkbd_writelines(3);
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}
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} else {
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if ((parkbd_counter == parkbd_mode + 10) || time_after(jiffies, parkbd_last + HZ/100)) {
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parkbd_counter = 0;
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parkbd_buffer = 0;
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}
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parkbd_buffer |= (parkbd_readlines() >> 1) << parkbd_counter++;
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if (parkbd_counter == parkbd_mode + 10)
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serio_interrupt(parkbd_port, (parkbd_buffer >> (2 - parkbd_mode)) & 0xff, 0);
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}
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parkbd_last = jiffies;
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}
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static int parkbd_getport(struct parport *pp)
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{
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struct pardev_cb parkbd_parport_cb;
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memset(&parkbd_parport_cb, 0, sizeof(parkbd_parport_cb));
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parkbd_parport_cb.irq_func = parkbd_interrupt;
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parkbd_parport_cb.flags = PARPORT_FLAG_EXCL;
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parkbd_dev = parport_register_dev_model(pp, "parkbd",
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&parkbd_parport_cb, 0);
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if (!parkbd_dev)
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return -ENODEV;
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if (parport_claim(parkbd_dev)) {
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parport_unregister_device(parkbd_dev);
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return -EBUSY;
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}
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parkbd_start = jiffies;
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return 0;
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}
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static struct serio *parkbd_allocate_serio(void)
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{
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struct serio *serio;
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serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
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if (serio) {
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serio->id.type = parkbd_mode;
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serio->write = parkbd_write,
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strlcpy(serio->name, "PARKBD AT/XT keyboard adapter", sizeof(serio->name));
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snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", parkbd_dev->port->name);
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}
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return serio;
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}
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static void parkbd_attach(struct parport *pp)
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{
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if (pp->number != parkbd_pp_no) {
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pr_debug("Not using parport%d.\n", pp->number);
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return;
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}
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if (parkbd_getport(pp))
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return;
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parkbd_port = parkbd_allocate_serio();
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if (!parkbd_port) {
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parport_release(parkbd_dev);
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parport_unregister_device(parkbd_dev);
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return;
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}
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parkbd_writelines(3);
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serio_register_port(parkbd_port);
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printk(KERN_INFO "serio: PARKBD %s adapter on %s\n",
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parkbd_mode ? "AT" : "XT", parkbd_dev->port->name);
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return;
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}
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static void parkbd_detach(struct parport *port)
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{
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if (!parkbd_port || port->number != parkbd_pp_no)
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return;
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parport_release(parkbd_dev);
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serio_unregister_port(parkbd_port);
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parport_unregister_device(parkbd_dev);
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parkbd_port = NULL;
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}
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static struct parport_driver parkbd_parport_driver = {
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.name = "parkbd",
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.match_port = parkbd_attach,
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.detach = parkbd_detach,
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.devmodel = true,
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};
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static int __init parkbd_init(void)
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{
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return parport_register_driver(&parkbd_parport_driver);
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}
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static void __exit parkbd_exit(void)
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{
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parport_unregister_driver(&parkbd_parport_driver);
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}
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module_init(parkbd_init);
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module_exit(parkbd_exit);
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