Subversion Repositories test_project

/*

 *  Parallel port to Keyboard port adapter driver for Linux

 *

 *  Copyright (c) 1999-2004 Vojtech Pavlik

 */

/*

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 as published by

 * the Free Software Foundation.

 */

/*

 * To connect an AT or XT keyboard to the parallel port, a fairly simple adapter

 * can be made:

 *

 *  Parallel port            Keyboard port

 *

 *     +5V --------------------- +5V (4)

 *

 *                 ______

 *     +5V -------|______|--.

 *                          |

 *     ACK (10) ------------|

 *                          |--- KBD CLOCK (5)

 *     STROBE (1) ---|<|----'

 *

 *                 ______

 *     +5V -------|______|--.

 *                          |

 *     BUSY (11) -----------|

 *                          |--- KBD DATA (1)

 *     AUTOFD (14) --|<|----'

 *

 *     GND (18-25) ------------- GND (3)

 *

 * The diodes can be fairly any type, and the resistors should be somewhere

 * around 5 kOhm, but the adapter will likely work without the resistors,

 * too.

 *

 * The +5V source can be taken either from USB, from mouse or keyboard ports,

 * or from a joystick port. Unfortunately, the parallel port of a PC doesn't

 * have a +5V pin, and feeding the keyboard from signal pins is out of question

 * with 300 mA power reqirement of a typical AT keyboard.

 */

#include <linux/module.h>

#include <linux/parport.h>

#include <linux/init.h>

#include <linux/serio.h>

MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");

MODULE_DESCRIPTION("Parallel port to Keyboard port adapter driver");

MODULE_LICENSE("GPL");

static unsigned int parkbd_pp_no;

module_param_named(port, parkbd_pp_no, int, 0);

MODULE_PARM_DESC(port, "Parallel port the adapter is connected to (default is 0)");

static unsigned int parkbd_mode = SERIO_8042;

module_param_named(mode, parkbd_mode, uint, 0);

MODULE_PARM_DESC(mode, "Mode of operation: XT = 0/AT = 1 (default)");

#define PARKBD_CLOCK    0x01    /* Strobe & Ack */

#define PARKBD_DATA     0x02    /* AutoFd & Busy */

static int parkbd_buffer;

static int parkbd_counter;

static unsigned long parkbd_last;

static int parkbd_writing;

static unsigned long parkbd_start;

static struct pardevice *parkbd_dev;

static struct serio *parkbd_port;

static int parkbd_readlines(void)

{

        return (parport_read_status(parkbd_dev->port) >> 6) ^ 2;

}

static void parkbd_writelines(int data)

{

        parport_write_control(parkbd_dev->port, (~data & 3) | 0x10);

}

static int parkbd_write(struct serio *port, unsigned char c)

{

        unsigned char p;

        if (!parkbd_mode) return -1;

        p = c ^ (c >> 4);

        p = p ^ (p >> 2);

        p = p ^ (p >> 1);

        parkbd_counter = 0;

        parkbd_writing = 1;

        parkbd_buffer = c | (((int) (~p & 1)) << 8) | 0x600;

        parkbd_writelines(2);

        return 0;

}

static void parkbd_interrupt(void *dev_id)

{

        if (parkbd_writing) {

                if (parkbd_counter && ((parkbd_counter == 11) || time_after(jiffies, parkbd_last + HZ/100))) {

                        parkbd_counter = 0;

                        parkbd_buffer = 0;

                        parkbd_writing = 0;

                        parkbd_writelines(3);

                        return;

                }

                parkbd_writelines(((parkbd_buffer >> parkbd_counter++) & 1) | 2);

                if (parkbd_counter == 11) {

                        parkbd_counter = 0;

                        parkbd_buffer = 0;

                        parkbd_writing = 0;

                        parkbd_writelines(3);

                }

        } else {

                if ((parkbd_counter == parkbd_mode + 10) || time_after(jiffies, parkbd_last + HZ/100)) {

                        parkbd_counter = 0;

                        parkbd_buffer = 0;

                }

                parkbd_buffer |= (parkbd_readlines() >> 1) << parkbd_counter++;

                if (parkbd_counter == parkbd_mode + 10)

                        serio_interrupt(parkbd_port, (parkbd_buffer >> (2 - parkbd_mode)) & 0xff, 0);

        }

        parkbd_last = jiffies;

}

static int parkbd_getport(void)

{

        struct parport *pp;

        pp = parport_find_number(parkbd_pp_no);

        if (pp == NULL) {

                printk(KERN_ERR "parkbd: no such parport\n");

                return -ENODEV;

        }

        parkbd_dev = parport_register_device(pp, "parkbd", NULL, NULL, parkbd_interrupt, PARPORT_DEV_EXCL, NULL);

        parport_put_port(pp);

        if (!parkbd_dev)

                return -ENODEV;

        if (parport_claim(parkbd_dev)) {

                parport_unregister_device(parkbd_dev);

                return -EBUSY;

        }

        parkbd_start = jiffies;

        return 0;

}

static struct serio * __init parkbd_allocate_serio(void)

{

        struct serio *serio;

        serio = kzalloc(sizeof(struct serio), GFP_KERNEL);

        if (serio) {

                serio->id.type = parkbd_mode;

                serio->write = parkbd_write,

                strlcpy(serio->name, "PARKBD AT/XT keyboard adapter", sizeof(serio->name));

                snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", parkbd_dev->port->name);

        }

        return serio;

}

static int __init parkbd_init(void)

{

        int err;

        err = parkbd_getport();

        if (err)

                return err;

        parkbd_port = parkbd_allocate_serio();

        if (!parkbd_port) {

                parport_release(parkbd_dev);

                return -ENOMEM;

        }

        parkbd_writelines(3);

        serio_register_port(parkbd_port);

        printk(KERN_INFO "serio: PARKBD %s adapter on %s\n",

                        parkbd_mode ? "AT" : "XT", parkbd_dev->port->name);

        return 0;

}

static void __exit parkbd_exit(void)

{

        parport_release(parkbd_dev);

        serio_unregister_port(parkbd_port);

        parport_unregister_device(parkbd_dev);

}

module_init(parkbd_init);

module_exit(parkbd_exit);