drivers/staging/comedi/drivers/comedi_parport.c

   1 /*
   2     comedi/drivers/comedi_parport.c
   3     hardware driver for standard parallel port
   4
   5     COMEDI - Linux Control and Measurement Device Interface
   6     Copyright (C) 1998,2001 David A. Schleef <ds@schleef.org>
   7
   8     This program is free software; you can redistribute it and/or modify
   9     it under the terms of the GNU General Public License as published by
  10     the Free Software Foundation; either version 2 of the License, or
  11     (at your option) any later version.
  12
  13     This program is distributed in the hope that it will be useful,
  14     but WITHOUT ANY WARRANTY; without even the implied warranty of
  15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16     GNU General Public License for more details.
  17
  18     You should have received a copy of the GNU General Public License
  19     along with this program; if not, write to the Free Software
  20     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21
  22 */
  23 /*
  24 Driver: comedi_parport
  25 Description: Standard PC parallel port
  26 Author: ds
  27 Status: works in immediate mode
  28 Devices: [standard] parallel port (comedi_parport)
  29 Updated: Tue, 30 Apr 2002 21:11:45 -0700
  30
  31 A cheap and easy way to get a few more digital I/O lines.  Steal
  32 additional parallel ports from old computers or your neighbors'
  33 computers.
  34
  35 Option list:
  36  0: I/O port base for the parallel port.
  37  1: IRQ
  38
  39 Parallel Port Lines:
  40
  41 pin     subdev  chan    aka
  42 ---     ------  ----    ---
  43 1       2       0       strobe
  44 2       0       0       data 0
  45 3       0       1       data 1
  46 4       0       2       data 2
  47 5       0       3       data 3
  48 6       0       4       data 4
  49 7       0       5       data 5
  50 8       0       6       data 6
  51 9       0       7       data 7
  52 10      1       3       acknowledge
  53 11      1       4       busy
  54 12      1       2       output
  55 13      1       1       printer selected
  56 14      2       1       auto LF
  57 15      1       0       error
  58 16      2       2       init
  59 17      2       3       select printer
  60 18-25   ground
  61
  62 Notes:
  63
  64 Subdevices 0 is digital I/O, subdevice 1 is digital input, and
  65 subdevice 2 is digital output.  Unlike other Comedi devices,
  66 subdevice 0 defaults to output.
  67
  68 Pins 13 and 14 are inverted once by Comedi and once by the
  69 hardware, thus cancelling the effect.
  70
  71 Pin 1 is a strobe, thus acts like one.  There's no way in software
  72 to change this, at least on a standard parallel port.
  73
  74 Subdevice 3 pretends to be a digital input subdevice, but it always
  75 returns 0 when read.  However, if you run a command with
  76 scan_begin_src=TRIG_EXT, it uses pin 10 as a external triggering
  77 pin, which can be used to wake up tasks.
  78 */
  79 /*
  80    see http://www.beyondlogic.org/ for information.
  81    or http://www.linux-magazin.de/ausgabe/1999/10/IO/io.html
  82  */
  83
  84 #include "../comedidev.h"
  85 #include <linux/interrupt.h>
  86 #include <linux/ioport.h>
  87
  88 #define PARPORT_SIZE 3
  89
  90 #define PARPORT_A 0
  91 #define PARPORT_B 1
  92 #define PARPORT_C 2
  93
  94 static int parport_attach(struct comedi_device *dev,
  95                           struct comedi_devconfig *it);
  96 static int parport_detach(struct comedi_device *dev);
  97 static struct comedi_driver driver_parport = {
  98         .driver_name = "comedi_parport",
  99         .module = THIS_MODULE,
 100         .attach = parport_attach,
 101         .detach = parport_detach,
 102 };
 103
 104 COMEDI_INITCLEANUP(driver_parport);
 105
 106 struct parport_private {
 107         unsigned int a_data;
 108         unsigned int c_data;
 109         int enable_irq;
 110 };
 111 #define devpriv ((struct parport_private *)(dev->private))
 112
 113 static int parport_insn_a(struct comedi_device *dev, struct comedi_subdevice *s,
 114                           struct comedi_insn *insn, unsigned int *data)
 115 {
 116         if (data[0]) {
 117                 devpriv->a_data &= ~data[0];
 118                 devpriv->a_data |= (data[0] & data[1]);
 119
 120                 outb(devpriv->a_data, dev->iobase + PARPORT_A);
 121         }
 122
 123         data[1] = inb(dev->iobase + PARPORT_A);
 124
 125         return 2;
 126 }
 127
 128 static int parport_insn_config_a(struct comedi_device *dev,
 129                                  struct comedi_subdevice *s,
 130                                  struct comedi_insn *insn, unsigned int *data)
 131 {
 132         if (data[0]) {
 133                 s->io_bits = 0xff;
 134                 devpriv->c_data &= ~(1 << 5);
 135         } else {
 136                 s->io_bits = 0;
 137                 devpriv->c_data |= (1 << 5);
 138         }
 139         outb(devpriv->c_data, dev->iobase + PARPORT_C);
 140
 141         return 1;
 142 }
 143
 144 static int parport_insn_b(struct comedi_device *dev, struct comedi_subdevice *s,
 145                           struct comedi_insn *insn, unsigned int *data)
 146 {
 147         if (data[0]) {
 148                 /* should writes be ignored? */
 149                 /* anyone??? */
 150         }
 151
 152         data[1] = (inb(dev->iobase + PARPORT_B) >> 3);
 153
 154         return 2;
 155 }
 156
 157 static int parport_insn_c(struct comedi_device *dev, struct comedi_subdevice *s,
 158                           struct comedi_insn *insn, unsigned int *data)
 159 {
 160         data[0] &= 0x0f;
 161         if (data[0]) {
 162                 devpriv->c_data &= ~data[0];
 163                 devpriv->c_data |= (data[0] & data[1]);
 164
 165                 outb(devpriv->c_data, dev->iobase + PARPORT_C);
 166         }
 167
 168         data[1] = devpriv->c_data & 0xf;
 169
 170         return 2;
 171 }
 172
 173 static int parport_intr_insn(struct comedi_device *dev,
 174                              struct comedi_subdevice *s,
 175                              struct comedi_insn *insn, unsigned int *data)
 176 {
 177         if (insn->n < 1)
 178                 return -EINVAL;
 179
 180         data[1] = 0;
 181         return 2;
 182 }
 183
 184 static int parport_intr_cmdtest(struct comedi_device *dev,
 185                                 struct comedi_subdevice *s,
 186                                 struct comedi_cmd *cmd)
 187 {
 188         int err = 0;
 189         int tmp;
 190
 191         /* step 1 */
 192
 193         tmp = cmd->start_src;
 194         cmd->start_src &= TRIG_NOW;
 195         if (!cmd->start_src || tmp != cmd->start_src)
 196                 err++;
 197
 198         tmp = cmd->scan_begin_src;
 199         cmd->scan_begin_src &= TRIG_EXT;
 200         if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
 201                 err++;
 202
 203         tmp = cmd->convert_src;
 204         cmd->convert_src &= TRIG_FOLLOW;
 205         if (!cmd->convert_src || tmp != cmd->convert_src)
 206                 err++;
 207
 208         tmp = cmd->scan_end_src;
 209         cmd->scan_end_src &= TRIG_COUNT;
 210         if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
 211                 err++;
 212
 213         tmp = cmd->stop_src;
 214         cmd->stop_src &= TRIG_NONE;
 215         if (!cmd->stop_src || tmp != cmd->stop_src)
 216                 err++;
 217
 218         if (err)
 219                 return 1;
 220
 221         /* step 2: ignored */
 222
 223         if (err)
 224                 return 2;
 225
 226         /* step 3: */
 227
 228         if (cmd->start_arg != 0) {
 229                 cmd->start_arg = 0;
 230                 err++;
 231         }
 232         if (cmd->scan_begin_arg != 0) {
 233                 cmd->scan_begin_arg = 0;
 234                 err++;
 235         }
 236         if (cmd->convert_arg != 0) {
 237                 cmd->convert_arg = 0;
 238                 err++;
 239         }
 240         if (cmd->scan_end_arg != 1) {
 241                 cmd->scan_end_arg = 1;
 242                 err++;
 243         }
 244         if (cmd->stop_arg != 0) {
 245                 cmd->stop_arg = 0;
 246                 err++;
 247         }
 248
 249         if (err)
 250                 return 3;
 251
 252         /* step 4: ignored */
 253
 254         if (err)
 255                 return 4;
 256
 257         return 0;
 258 }
 259
 260 static int parport_intr_cmd(struct comedi_device *dev,
 261                             struct comedi_subdevice *s)
 262 {
 263         devpriv->c_data |= 0x10;
 264         outb(devpriv->c_data, dev->iobase + PARPORT_C);
 265
 266         devpriv->enable_irq = 1;
 267
 268         return 0;
 269 }
 270
 271 static int parport_intr_cancel(struct comedi_device *dev,
 272                                struct comedi_subdevice *s)
 273 {
 274         printk(KERN_DEBUG "parport_intr_cancel()\n");
 275
 276         devpriv->c_data &= ~0x10;
 277         outb(devpriv->c_data, dev->iobase + PARPORT_C);
 278
 279         devpriv->enable_irq = 0;
 280
 281         return 0;
 282 }
 283
 284 static irqreturn_t parport_interrupt(int irq, void *d)
 285 {
 286         struct comedi_device *dev = d;
 287         struct comedi_subdevice *s = dev->subdevices + 3;
 288
 289         if (!devpriv->enable_irq) {
 290                 printk(KERN_ERR "comedi_parport: bogus irq, ignored\n");
 291                 return IRQ_NONE;
 292         }
 293
 294         comedi_buf_put(s->async, 0);
 295         s->async->events |= COMEDI_CB_BLOCK | COMEDI_CB_EOS;
 296
 297         comedi_event(dev, s);
 298         return IRQ_HANDLED;
 299 }
 300
 301 static int parport_attach(struct comedi_device *dev,
 302                           struct comedi_devconfig *it)
 303 {
 304         int ret;
 305         unsigned int irq;
 306         unsigned long iobase;
 307         struct comedi_subdevice *s;
 308
 309         iobase = it->options[0];
 310         printk(KERN_INFO "comedi%d: parport: 0x%04lx ", dev->minor, iobase);
 311         if (!request_region(iobase, PARPORT_SIZE, "parport (comedi)")) {
 312                 printk(KERN_ERR "I/O port conflict\n");
 313                 return -EIO;
 314         }
 315         dev->iobase = iobase;
 316
 317         irq = it->options[1];
 318         if (irq) {
 319                 printk(KERN_INFO " irq=%u", irq);
 320                 ret = request_irq(irq, parport_interrupt, 0, "comedi_parport",
 321                                   dev);
 322                 if (ret < 0) {
 323                         printk(KERN_ERR " irq not available\n");
 324                         return -EINVAL;
 325                 }
 326                 dev->irq = irq;
 327         }
 328         dev->board_name = "parport";
 329
 330         ret = alloc_subdevices(dev, 4);
 331         if (ret < 0)
 332                 return ret;
 333         ret = alloc_private(dev, sizeof(struct parport_private));
 334         if (ret < 0)
 335                 return ret;
 336
 337         s = dev->subdevices + 0;
 338         s->type = COMEDI_SUBD_DIO;
 339         s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
 340         s->n_chan = 8;
 341         s->maxdata = 1;
 342         s->range_table = &range_digital;
 343         s->insn_bits = parport_insn_a;
 344         s->insn_config = parport_insn_config_a;
 345
 346         s = dev->subdevices + 1;
 347         s->type = COMEDI_SUBD_DI;
 348         s->subdev_flags = SDF_READABLE;
 349         s->n_chan = 5;
 350         s->maxdata = 1;
 351         s->range_table = &range_digital;
 352         s->insn_bits = parport_insn_b;
 353
 354         s = dev->subdevices + 2;
 355         s->type = COMEDI_SUBD_DO;
 356         s->subdev_flags = SDF_WRITABLE;
 357         s->n_chan = 4;
 358         s->maxdata = 1;
 359         s->range_table = &range_digital;
 360         s->insn_bits = parport_insn_c;
 361
 362         s = dev->subdevices + 3;
 363         if (irq) {
 364                 dev->read_subdev = s;
 365                 s->type = COMEDI_SUBD_DI;
 366                 s->subdev_flags = SDF_READABLE | SDF_CMD_READ;
 367                 s->n_chan = 1;
 368                 s->maxdata = 1;
 369                 s->range_table = &range_digital;
 370                 s->insn_bits = parport_intr_insn;
 371                 s->do_cmdtest = parport_intr_cmdtest;
 372                 s->do_cmd = parport_intr_cmd;
 373                 s->cancel = parport_intr_cancel;
 374         } else {
 375                 s->type = COMEDI_SUBD_UNUSED;
 376         }
 377
 378         devpriv->a_data = 0;
 379         outb(devpriv->a_data, dev->iobase + PARPORT_A);
 380         devpriv->c_data = 0;
 381         outb(devpriv->c_data, dev->iobase + PARPORT_C);
 382
 383         printk(KERN_INFO "\n");
 384         return 1;
 385 }
 386
 387 static int parport_detach(struct comedi_device *dev)
 388 {
 389         printk(KERN_INFO "comedi%d: parport: remove\n", dev->minor);
 390
 391         if (dev->iobase)
 392                 release_region(dev->iobase, PARPORT_SIZE);
 393
 394         if (dev->irq)
 395                 free_irq(dev->irq, dev);
 396
 397         return 0;
 398 }