drivers/input/serio/parkbd.c

   1 /*
   2  * $Id: parkbd.c,v 1.10 2002/03/13 10:09:20 vojtech Exp $
   3  *
   4  *  Copyright (c) 1999-2001 Vojtech Pavlik
   5  */
   6
   7 /*
   8  *  Parallel port to Keyboard port adapter driver for Linux
   9  */
  10
  11 /*
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  25  *
  26  * Should you need to contact me, the author, you can do so either by
  27  * e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
  28  * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
  29  */
  30
  31 #include <linux/module.h>
  32 #include <linux/parport.h>
  33 #include <linux/init.h>
  34 #include <linux/serio.h>
  35
  36 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  37 MODULE_DESCRIPTION("Parallel port to Keyboard port adapter driver");
  38 MODULE_LICENSE("GPL");
  39
  40 MODULE_PARM(parkbd, "1i");
  41 MODULE_PARM(parkbd_mode, "1i");
  42
  43 #define PARKBD_CLOCK    0x01    /* Strobe & Ack */
  44 #define PARKBD_DATA     0x02    /* AutoFd & Busy */
  45
  46 static int parkbd;
  47 static int parkbd_mode = SERIO_8042;
  48
  49 static int parkbd_buffer;
  50 static int parkbd_counter;
  51 static unsigned long parkbd_last;
  52 static int parkbd_writing;
  53 static unsigned long parkbd_start;
  54
  55 static struct pardevice *parkbd_dev;
  56 static struct serio *parkbd_port;
  57
  58 static int parkbd_readlines(void)
  59 {
  60         return (parport_read_status(parkbd_dev->port) >> 6) ^ 2;
  61 }
  62
  63 static void parkbd_writelines(int data)
  64 {
  65         parport_write_control(parkbd_dev->port, (~data & 3) | 0x10);
  66 }
  67
  68 static int parkbd_write(struct serio *port, unsigned char c)
  69 {
  70         unsigned char p;
  71
  72         if (!parkbd_mode) return -1;
  73
  74         p = c ^ (c >> 4);
  75         p = p ^ (p >> 2);
  76         p = p ^ (p >> 1);
  77
  78         parkbd_counter = 0;
  79         parkbd_writing = 1;
  80         parkbd_buffer = c | (((int) (~p & 1)) << 8) | 0x600;
  81
  82         parkbd_writelines(2);
  83
  84         return 0;
  85 }
  86
  87 static void parkbd_interrupt(int irq, void *dev_id, struct pt_regs *regs)
  88 {
  89
  90         if (parkbd_writing) {
  91
  92                 if (parkbd_counter && ((parkbd_counter == 11) || time_after(jiffies, parkbd_last + HZ/100))) {
  93                         parkbd_counter = 0;
  94                         parkbd_buffer = 0;
  95                         parkbd_writing = 0;
  96                         parkbd_writelines(3);
  97                         return;
  98                 }
  99
 100                 parkbd_writelines(((parkbd_buffer >> parkbd_counter++) & 1) | 2);
 101
 102                 if (parkbd_counter == 11) {
 103                         parkbd_counter = 0;
 104                         parkbd_buffer = 0;
 105                         parkbd_writing = 0;
 106                         parkbd_writelines(3);
 107                 }
 108
 109         } else {
 110
 111                 if ((parkbd_counter == parkbd_mode + 10) || time_after(jiffies, parkbd_last + HZ/100)) {
 112                         parkbd_counter = 0;
 113                         parkbd_buffer = 0;
 114                 }
 115
 116                 parkbd_buffer |= (parkbd_readlines() >> 1) << parkbd_counter++;
 117
 118                 if (parkbd_counter == parkbd_mode + 10)
 119                         serio_interrupt(parkbd_port, (parkbd_buffer >> (2 - parkbd_mode)) & 0xff, 0, regs);
 120         }
 121
 122         parkbd_last = jiffies;
 123 }
 124
 125 static int parkbd_getport(void)
 126 {
 127         struct parport *pp;
 128
 129         if (parkbd < 0) {
 130                 printk(KERN_ERR "parkbd: no port specified\n");
 131                 return -ENODEV;
 132         }
 133
 134         pp = parport_find_number(parkbd);
 135
 136         if (pp == NULL) {
 137                 printk(KERN_ERR "parkbd: no such parport\n");
 138                 return -ENODEV;
 139         }
 140
 141         parkbd_dev = parport_register_device(pp, "parkbd", NULL, NULL, parkbd_interrupt, PARPORT_DEV_EXCL, NULL);
 142         parport_put_port(pp);
 143
 144         if (!parkbd_dev)
 145                 return -ENODEV;
 146
 147         if (parport_claim(parkbd_dev)) {
 148                 parport_unregister_device(parkbd_dev);
 149                 return -EBUSY;
 150         }
 151
 152         parkbd_start = jiffies;
 153
 154         return 0;
 155 }
 156
 157 static struct serio * __init parkbd_allocate_serio(void)
 158 {
 159         struct serio *serio;
 160
 161         serio = kmalloc(sizeof(struct serio), GFP_KERNEL);
 162         if (serio) {
 163                 memset(serio, 0, sizeof(struct serio));
 164                 serio->type = parkbd_mode;
 165                 serio->write = parkbd_write,
 166                 strlcpy(serio->name, "PARKBD AT/XT keyboard adapter", sizeof(serio->name));
 167                 snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", parkbd_dev->port->name);
 168         }
 169
 170         return serio;
 171 }
 172
 173 int __init parkbd_init(void)
 174 {
 175         int err;
 176
 177         err = parkbd_getport();
 178         if (err)
 179                 return err;
 180
 181         parkbd_port = parkbd_allocate_serio();
 182         if (!parkbd_port) {
 183                 parport_release(parkbd_dev);
 184                 return -ENOMEM;
 185         }
 186
 187         parkbd_writelines(3);
 188
 189         serio_register_port(parkbd_port);
 190
 191         printk(KERN_INFO "serio: PARKBD %s adapter on %s\n",
 192                         parkbd_mode ? "AT" : "XT", parkbd_dev->port->name);
 193
 194         return 0;
 195 }
 196
 197 void __exit parkbd_exit(void)
 198 {
 199         parport_release(parkbd_dev);
 200         serio_unregister_port(parkbd_port);
 201         parport_unregister_device(parkbd_dev);
 202 }
 203
 204 module_init(parkbd_init);
 205 module_exit(parkbd_exit);