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/ioport.h>
  86
  87 #define PARPORT_SIZE 3
  88
  89 #define PARPORT_A 0
  90 #define PARPORT_B 1
  91 #define PARPORT_C 2
  92
  93 static int parport_attach(comedi_device *dev, comedi_devconfig *it);
  94 static int parport_detach(comedi_device *dev);
  95 static comedi_driver driver_parport = {
  96       .driver_name =    "comedi_parport",
  97       .module =         THIS_MODULE,
  98       .attach =         parport_attach,
  99       .detach =         parport_detach,
 100 };
 101
 102 COMEDI_INITCLEANUP(driver_parport);
 103
 104 struct parport_private {
 105         unsigned int a_data;
 106         unsigned int c_data;
 107         int enable_irq;
 108 };
 109 #define devpriv ((struct parport_private *)(dev->private))
 110
 111 static int parport_insn_a(comedi_device *dev, comedi_subdevice *s,
 112                           comedi_insn *insn, lsampl_t *data)
 113 {
 114         if (data[0]) {
 115                 devpriv->a_data &= ~data[0];
 116                 devpriv->a_data |= (data[0] & data[1]);
 117
 118                 outb(devpriv->a_data, dev->iobase + PARPORT_A);
 119         }
 120
 121         data[1] = inb(dev->iobase + PARPORT_A);
 122
 123         return 2;
 124 }
 125
 126 static int parport_insn_config_a(comedi_device *dev, comedi_subdevice *s,
 127                                  comedi_insn *insn, lsampl_t *data)
 128 {
 129         if (data[0]) {
 130                 s->io_bits = 0xff;
 131                 devpriv->c_data &= ~(1 << 5);
 132         } else {
 133                 s->io_bits = 0;
 134                 devpriv->c_data |= (1 << 5);
 135         }
 136         outb(devpriv->c_data, dev->iobase + PARPORT_C);
 137
 138         return 1;
 139 }
 140
 141 static int parport_insn_b(comedi_device *dev, comedi_subdevice *s,
 142                           comedi_insn *insn, lsampl_t *data)
 143 {
 144         if (data[0]) {
 145                 /* should writes be ignored? */
 146                 /* anyone??? */
 147         }
 148
 149         data[1] = (inb(dev->iobase + PARPORT_B) >> 3);
 150
 151         return 2;
 152 }
 153
 154 static int parport_insn_c(comedi_device *dev, comedi_subdevice *s,
 155                           comedi_insn *insn, lsampl_t *data)
 156 {
 157         data[0] &= 0x0f;
 158         if (data[0]) {
 159                 devpriv->c_data &= ~data[0];
 160                 devpriv->c_data |= (data[0] & data[1]);
 161
 162                 outb(devpriv->c_data, dev->iobase + PARPORT_C);
 163         }
 164
 165         data[1] = devpriv->c_data & 0xf;
 166
 167         return 2;
 168 }
 169
 170 static int parport_intr_insn(comedi_device *dev, comedi_subdevice *s,
 171                              comedi_insn *insn, lsampl_t *data)
 172 {
 173         if (insn->n < 1)
 174                 return -EINVAL;
 175
 176         data[1] = 0;
 177         return 2;
 178 }
 179
 180 static int parport_intr_cmdtest(comedi_device *dev, comedi_subdevice *s,
 181                                 comedi_cmd *cmd)
 182 {
 183         int err = 0;
 184         int tmp;
 185
 186         /* step 1 */
 187
 188         tmp = cmd->start_src;
 189         cmd->start_src &= TRIG_NOW;
 190         if (!cmd->start_src || tmp != cmd->start_src)
 191                 err++;
 192
 193         tmp = cmd->scan_begin_src;
 194         cmd->scan_begin_src &= TRIG_EXT;
 195         if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
 196                 err++;
 197
 198         tmp = cmd->convert_src;
 199         cmd->convert_src &= TRIG_FOLLOW;
 200         if (!cmd->convert_src || tmp != cmd->convert_src)
 201                 err++;
 202
 203         tmp = cmd->scan_end_src;
 204         cmd->scan_end_src &= TRIG_COUNT;
 205         if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
 206                 err++;
 207
 208         tmp = cmd->stop_src;
 209         cmd->stop_src &= TRIG_NONE;
 210         if (!cmd->stop_src || tmp != cmd->stop_src)
 211                 err++;
 212
 213         if (err)
 214                 return 1;
 215
 216         /* step 2: ignored */
 217
 218         if (err)
 219                 return 2;
 220
 221         /* step 3: */
 222
 223         if (cmd->start_arg != 0) {
 224                 cmd->start_arg = 0;
 225                 err++;
 226         }
 227         if (cmd->scan_begin_arg != 0) {
 228                 cmd->scan_begin_arg = 0;
 229                 err++;
 230         }
 231         if (cmd->convert_arg != 0) {
 232                 cmd->convert_arg = 0;
 233                 err++;
 234         }
 235         if (cmd->scan_end_arg != 1) {
 236                 cmd->scan_end_arg = 1;
 237                 err++;
 238         }
 239         if (cmd->stop_arg != 0) {
 240                 cmd->stop_arg = 0;
 241                 err++;
 242         }
 243
 244         if (err)
 245                 return 3;
 246
 247         /* step 4: ignored */
 248
 249         if (err)
 250                 return 4;
 251
 252         return 0;
 253 }
 254
 255 static int parport_intr_cmd(comedi_device *dev, comedi_subdevice *s)
 256 {
 257         devpriv->c_data |= 0x10;
 258         outb(devpriv->c_data, dev->iobase + PARPORT_C);
 259
 260         devpriv->enable_irq = 1;
 261
 262         return 0;
 263 }
 264
 265 static int parport_intr_cancel(comedi_device *dev, comedi_subdevice *s)
 266 {
 267         printk(KERN_DEBUG "parport_intr_cancel()\n");
 268
 269         devpriv->c_data &= ~0x10;
 270         outb(devpriv->c_data, dev->iobase + PARPORT_C);
 271
 272         devpriv->enable_irq = 0;
 273
 274         return 0;
 275 }
 276
 277 static irqreturn_t parport_interrupt(int irq, void *d PT_REGS_ARG)
 278 {
 279         comedi_device *dev = d;
 280         comedi_subdevice *s = dev->subdevices + 3;
 281
 282         if (!devpriv->enable_irq) {
 283                 printk(KERN_ERR "comedi_parport: bogus irq, ignored\n");
 284                 return IRQ_NONE;
 285         }
 286
 287         comedi_buf_put(s->async, 0);
 288         s->async->events |= COMEDI_CB_BLOCK | COMEDI_CB_EOS;
 289
 290         comedi_event(dev, s);
 291         return IRQ_HANDLED;
 292 }
 293
 294 static int parport_attach(comedi_device *dev, comedi_devconfig *it)
 295 {
 296         int ret;
 297         unsigned int irq;
 298         unsigned long iobase;
 299         comedi_subdevice *s;
 300
 301         iobase = it->options[0];
 302         printk(KERN_INFO "comedi%d: parport: 0x%04lx ", dev->minor, iobase);
 303         if (!request_region(iobase, PARPORT_SIZE, "parport (comedi)")) {
 304                 printk("I/O port conflict\n");
 305                 return -EIO;
 306         }
 307         dev->iobase = iobase;
 308
 309         irq = it->options[1];
 310         if (irq) {
 311                 printk(" irq=%u", irq);
 312                 ret = comedi_request_irq(irq, parport_interrupt, 0,
 313                         "comedi_parport", dev);
 314                 if (ret < 0) {
 315                         printk(" irq not available\n");
 316                         return -EINVAL;
 317                 }
 318                 dev->irq = irq;
 319         }
 320         dev->board_name = "parport";
 321
 322         ret = alloc_subdevices(dev, 4);
 323         if (ret < 0)
 324                 return ret;
 325         ret = alloc_private(dev, sizeof(struct parport_private));
 326         if (ret < 0)
 327                 return ret;
 328
 329         s = dev->subdevices + 0;
 330         s->type = COMEDI_SUBD_DIO;
 331         s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
 332         s->n_chan = 8;
 333         s->maxdata = 1;
 334         s->range_table = &range_digital;
 335         s->insn_bits = parport_insn_a;
 336         s->insn_config = parport_insn_config_a;
 337
 338         s = dev->subdevices + 1;
 339         s->type = COMEDI_SUBD_DI;
 340         s->subdev_flags = SDF_READABLE;
 341         s->n_chan = 5;
 342         s->maxdata = 1;
 343         s->range_table = &range_digital;
 344         s->insn_bits = parport_insn_b;
 345
 346         s = dev->subdevices + 2;
 347         s->type = COMEDI_SUBD_DO;
 348         s->subdev_flags = SDF_WRITABLE;
 349         s->n_chan = 4;
 350         s->maxdata = 1;
 351         s->range_table = &range_digital;
 352         s->insn_bits = parport_insn_c;
 353
 354         s = dev->subdevices + 3;
 355         if (irq) {
 356                 dev->read_subdev = s;
 357                 s->type = COMEDI_SUBD_DI;
 358                 s->subdev_flags = SDF_READABLE | SDF_CMD_READ;
 359                 s->n_chan = 1;
 360                 s->maxdata = 1;
 361                 s->range_table = &range_digital;
 362                 s->insn_bits = parport_intr_insn;
 363                 s->do_cmdtest = parport_intr_cmdtest;
 364                 s->do_cmd = parport_intr_cmd;
 365                 s->cancel = parport_intr_cancel;
 366         } else {
 367                 s->type = COMEDI_SUBD_UNUSED;
 368         }
 369
 370         devpriv->a_data = 0;
 371         outb(devpriv->a_data, dev->iobase + PARPORT_A);
 372         devpriv->c_data = 0;
 373         outb(devpriv->c_data, dev->iobase + PARPORT_C);
 374
 375         printk("\n");
 376         return 1;
 377 }
 378
 379 static int parport_detach(comedi_device *dev)
 380 {
 381         printk("comedi%d: parport: remove\n", dev->minor);
 382
 383         if (dev->iobase)
 384                 release_region(dev->iobase, PARPORT_SIZE);
 385
 386         if (dev->irq)
 387                 comedi_free_irq(dev->irq, dev);
 388
 389         return 0;
 390 }