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, struct comedi_devconfig *it);
  95 static int parport_detach(struct comedi_device *dev);
  96 static struct comedi_driver driver_parport = {
  97       .driver_name =    "comedi_parport",
  98       .module =         THIS_MODULE,
  99       .attach =         parport_attach,
 100       .detach =         parport_detach,
 101 };
 102
 103 COMEDI_INITCLEANUP(driver_parport);
 104
 105 struct parport_private {
 106         unsigned int a_data;
 107         unsigned int c_data;
 108         int enable_irq;
 109 };
 110 #define devpriv ((struct parport_private *)(dev->private))
 111
 112 static int parport_insn_a(struct comedi_device *dev, struct comedi_subdevice *s,
 113                           struct comedi_insn *insn, unsigned int *data)
 114 {
 115         if (data[0]) {
 116                 devpriv->a_data &= ~data[0];
 117                 devpriv->a_data |= (data[0] & data[1]);
 118
 119                 outb(devpriv->a_data, dev->iobase + PARPORT_A);
 120         }
 121
 122         data[1] = inb(dev->iobase + PARPORT_A);
 123
 124         return 2;
 125 }
 126
 127 static int parport_insn_config_a(struct comedi_device *dev, struct comedi_subdevice *s,
 128                                  struct comedi_insn *insn, unsigned int *data)
 129 {
 130         if (data[0]) {
 131                 s->io_bits = 0xff;
 132                 devpriv->c_data &= ~(1 << 5);
 133         } else {
 134                 s->io_bits = 0;
 135                 devpriv->c_data |= (1 << 5);
 136         }
 137         outb(devpriv->c_data, dev->iobase + PARPORT_C);
 138
 139         return 1;
 140 }
 141
 142 static int parport_insn_b(struct comedi_device *dev, struct comedi_subdevice *s,
 143                           struct comedi_insn *insn, unsigned int *data)
 144 {
 145         if (data[0]) {
 146                 /* should writes be ignored? */
 147                 /* anyone??? */
 148         }
 149
 150         data[1] = (inb(dev->iobase + PARPORT_B) >> 3);
 151
 152         return 2;
 153 }
 154
 155 static int parport_insn_c(struct comedi_device *dev, struct comedi_subdevice *s,
 156                           struct comedi_insn *insn, unsigned int *data)
 157 {
 158         data[0] &= 0x0f;
 159         if (data[0]) {
 160                 devpriv->c_data &= ~data[0];
 161                 devpriv->c_data |= (data[0] & data[1]);
 162
 163                 outb(devpriv->c_data, dev->iobase + PARPORT_C);
 164         }
 165
 166         data[1] = devpriv->c_data & 0xf;
 167
 168         return 2;
 169 }
 170
 171 static int parport_intr_insn(struct comedi_device *dev, struct comedi_subdevice *s,
 172                              struct comedi_insn *insn, unsigned int *data)
 173 {
 174         if (insn->n < 1)
 175                 return -EINVAL;
 176
 177         data[1] = 0;
 178         return 2;
 179 }
 180
 181 static int parport_intr_cmdtest(struct comedi_device *dev, struct comedi_subdevice *s,
 182                                 struct comedi_cmd *cmd)
 183 {
 184         int err = 0;
 185         int tmp;
 186
 187         /* step 1 */
 188
 189         tmp = cmd->start_src;
 190         cmd->start_src &= TRIG_NOW;
 191         if (!cmd->start_src || tmp != cmd->start_src)
 192                 err++;
 193
 194         tmp = cmd->scan_begin_src;
 195         cmd->scan_begin_src &= TRIG_EXT;
 196         if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
 197                 err++;
 198
 199         tmp = cmd->convert_src;
 200         cmd->convert_src &= TRIG_FOLLOW;
 201         if (!cmd->convert_src || tmp != cmd->convert_src)
 202                 err++;
 203
 204         tmp = cmd->scan_end_src;
 205         cmd->scan_end_src &= TRIG_COUNT;
 206         if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
 207                 err++;
 208
 209         tmp = cmd->stop_src;
 210         cmd->stop_src &= TRIG_NONE;
 211         if (!cmd->stop_src || tmp != cmd->stop_src)
 212                 err++;
 213
 214         if (err)
 215                 return 1;
 216
 217         /* step 2: ignored */
 218
 219         if (err)
 220                 return 2;
 221
 222         /* step 3: */
 223
 224         if (cmd->start_arg != 0) {
 225                 cmd->start_arg = 0;
 226                 err++;
 227         }
 228         if (cmd->scan_begin_arg != 0) {
 229                 cmd->scan_begin_arg = 0;
 230                 err++;
 231         }
 232         if (cmd->convert_arg != 0) {
 233                 cmd->convert_arg = 0;
 234                 err++;
 235         }
 236         if (cmd->scan_end_arg != 1) {
 237                 cmd->scan_end_arg = 1;
 238                 err++;
 239         }
 240         if (cmd->stop_arg != 0) {
 241                 cmd->stop_arg = 0;
 242                 err++;
 243         }
 244
 245         if (err)
 246                 return 3;
 247
 248         /* step 4: ignored */
 249
 250         if (err)
 251                 return 4;
 252
 253         return 0;
 254 }
 255
 256 static int parport_intr_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 257 {
 258         devpriv->c_data |= 0x10;
 259         outb(devpriv->c_data, dev->iobase + PARPORT_C);
 260
 261         devpriv->enable_irq = 1;
 262
 263         return 0;
 264 }
 265
 266 static int parport_intr_cancel(struct comedi_device *dev, struct comedi_subdevice *s)
 267 {
 268         printk(KERN_DEBUG "parport_intr_cancel()\n");
 269
 270         devpriv->c_data &= ~0x10;
 271         outb(devpriv->c_data, dev->iobase + PARPORT_C);
 272
 273         devpriv->enable_irq = 0;
 274
 275         return 0;
 276 }
 277
 278 static irqreturn_t parport_interrupt(int irq, void *d)
 279 {
 280         struct comedi_device *dev = d;
 281         struct comedi_subdevice *s = dev->subdevices + 3;
 282
 283         if (!devpriv->enable_irq) {
 284                 printk(KERN_ERR "comedi_parport: bogus irq, ignored\n");
 285                 return IRQ_NONE;
 286         }
 287
 288         comedi_buf_put(s->async, 0);
 289         s->async->events |= COMEDI_CB_BLOCK | COMEDI_CB_EOS;
 290
 291         comedi_event(dev, s);
 292         return IRQ_HANDLED;
 293 }
 294
 295 static int parport_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 296 {
 297         int ret;
 298         unsigned int irq;
 299         unsigned long iobase;
 300         struct comedi_subdevice *s;
 301
 302         iobase = it->options[0];
 303         printk(KERN_INFO "comedi%d: parport: 0x%04lx ", dev->minor, iobase);
 304         if (!request_region(iobase, PARPORT_SIZE, "parport (comedi)")) {
 305                 printk("I/O port conflict\n");
 306                 return -EIO;
 307         }
 308         dev->iobase = iobase;
 309
 310         irq = it->options[1];
 311         if (irq) {
 312                 printk(" irq=%u", irq);
 313                 ret = request_irq(irq, parport_interrupt, 0, "comedi_parport",
 314                                   dev);
 315                 if (ret < 0) {
 316                         printk(" irq not available\n");
 317                         return -EINVAL;
 318                 }
 319                 dev->irq = irq;
 320         }
 321         dev->board_name = "parport";
 322
 323         ret = alloc_subdevices(dev, 4);
 324         if (ret < 0)
 325                 return ret;
 326         ret = alloc_private(dev, sizeof(struct parport_private));
 327         if (ret < 0)
 328                 return ret;
 329
 330         s = dev->subdevices + 0;
 331         s->type = COMEDI_SUBD_DIO;
 332         s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
 333         s->n_chan = 8;
 334         s->maxdata = 1;
 335         s->range_table = &range_digital;
 336         s->insn_bits = parport_insn_a;
 337         s->insn_config = parport_insn_config_a;
 338
 339         s = dev->subdevices + 1;
 340         s->type = COMEDI_SUBD_DI;
 341         s->subdev_flags = SDF_READABLE;
 342         s->n_chan = 5;
 343         s->maxdata = 1;
 344         s->range_table = &range_digital;
 345         s->insn_bits = parport_insn_b;
 346
 347         s = dev->subdevices + 2;
 348         s->type = COMEDI_SUBD_DO;
 349         s->subdev_flags = SDF_WRITABLE;
 350         s->n_chan = 4;
 351         s->maxdata = 1;
 352         s->range_table = &range_digital;
 353         s->insn_bits = parport_insn_c;
 354
 355         s = dev->subdevices + 3;
 356         if (irq) {
 357                 dev->read_subdev = s;
 358                 s->type = COMEDI_SUBD_DI;
 359                 s->subdev_flags = SDF_READABLE | SDF_CMD_READ;
 360                 s->n_chan = 1;
 361                 s->maxdata = 1;
 362                 s->range_table = &range_digital;
 363                 s->insn_bits = parport_intr_insn;
 364                 s->do_cmdtest = parport_intr_cmdtest;
 365                 s->do_cmd = parport_intr_cmd;
 366                 s->cancel = parport_intr_cancel;
 367         } else {
 368                 s->type = COMEDI_SUBD_UNUSED;
 369         }
 370
 371         devpriv->a_data = 0;
 372         outb(devpriv->a_data, dev->iobase + PARPORT_A);
 373         devpriv->c_data = 0;
 374         outb(devpriv->c_data, dev->iobase + PARPORT_C);
 375
 376         printk("\n");
 377         return 1;
 378 }
 379
 380 static int parport_detach(struct comedi_device *dev)
 381 {
 382         printk("comedi%d: parport: remove\n", dev->minor);
 383
 384         if (dev->iobase)
 385                 release_region(dev->iobase, PARPORT_SIZE);
 386
 387         if (dev->irq)
 388                 free_irq(dev->irq, dev);
 389
 390         return 0;
 391 }