drivers/staging/comedi/drivers/8255.c

   1 /*
   2     comedi/drivers/8255.c
   3     Driver for 8255
   4
   5     COMEDI - Linux Control and Measurement Device Interface
   6     Copyright (C) 1998 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: 8255
  25 Description: generic 8255 support
  26 Devices: [standard] 8255 (8255)
  27 Author: ds
  28 Status: works
  29 Updated: Fri,  7 Jun 2002 12:56:45 -0700
  30
  31 The classic in digital I/O.  The 8255 appears in Comedi as a single
  32 digital I/O subdevice with 24 channels.  The channel 0 corresponds
  33 to the 8255's port A, bit 0; channel 23 corresponds to port C, bit
  34 7.  Direction configuration is done in blocks, with channels 0-7,
  35 8-15, 16-19, and 20-23 making up the 4 blocks.  The only 8255 mode
  36 supported is mode 0.
  37
  38 You should enable compilation this driver if you plan to use a board
  39 that has an 8255 chip.  For multifunction boards, the main driver will
  40 configure the 8255 subdevice automatically.
  41
  42 This driver also works independently with ISA and PCI cards that
  43 directly map the 8255 registers to I/O ports, including cards with
  44 multiple 8255 chips.  To configure the driver for such a card, the
  45 option list should be a list of the I/O port bases for each of the
  46 8255 chips.  For example,
  47
  48   comedi_config /dev/comedi0 8255 0x200,0x204,0x208,0x20c
  49
  50 Note that most PCI 8255 boards do NOT work with this driver, and
  51 need a separate driver as a wrapper.  For those that do work, the
  52 I/O port base address can be found in the output of 'lspci -v'.
  53
  54 */
  55
  56 /*
  57    This file contains an exported subdevice for driving an 8255.
  58
  59    To use this subdevice as part of another driver, you need to
  60    set up the subdevice in the attach function of the driver by
  61    calling:
  62
  63      subdev_8255_init(device, subdevice, callback_function, arg)
  64
  65    device and subdevice are pointers to the device and subdevice
  66    structures.  callback_function will be called to provide the
  67    low-level input/output to the device, i.e., actual register
  68    access.  callback_function will be called with the value of arg
  69    as the last parameter.  If the 8255 device is mapped as 4
  70    consecutive I/O ports, you can use NULL for callback_function
  71    and the I/O port base for arg, and an internal function will
  72    handle the register access.
  73
  74    In addition, if the main driver handles interrupts, you can
  75    enable commands on the subdevice by calling subdev_8255_init_irq()
  76    instead.  Then, when you get an interrupt that is likely to be
  77    from the 8255, you should call subdev_8255_interrupt(), which
  78    will copy the latched value to a Comedi buffer.
  79  */
  80
  81 #include "../comedidev.h"
  82
  83 #include <linux/ioport.h>
  84
  85 #define _8255_SIZE 4
  86
  87 #define _8255_DATA 0
  88 #define _8255_CR 3
  89
  90 #define CR_C_LO_IO      0x01
  91 #define CR_B_IO         0x02
  92 #define CR_B_MODE       0x04
  93 #define CR_C_HI_IO      0x08
  94 #define CR_A_IO         0x10
  95 #define CR_A_MODE(a)    ((a)<<5)
  96 #define CR_CW           0x80
  97
  98 struct subdev_8255_struct {
  99         unsigned long cb_arg;
 100         int (*cb_func) (int, int, int, unsigned long);
 101         int have_irq;
 102 };
 103
 104 #define CALLBACK_ARG    (((struct subdev_8255_struct *)s->private)->cb_arg)
 105 #define CALLBACK_FUNC   (((struct subdev_8255_struct *)s->private)->cb_func)
 106 #define subdevpriv      ((struct subdev_8255_struct *)s->private)
 107
 108 static int dev_8255_attach(struct comedi_device *dev, struct comedi_devconfig * it);
 109 static int dev_8255_detach(struct comedi_device *dev);
 110 static struct comedi_driver driver_8255 = {
 111       driver_name:"8255",
 112       module:THIS_MODULE,
 113       attach:dev_8255_attach,
 114       detach:dev_8255_detach,
 115 };
 116
 117 COMEDI_INITCLEANUP(driver_8255);
 118
 119 static void do_config(struct comedi_device *dev, struct comedi_subdevice * s);
 120
 121 void subdev_8255_interrupt(struct comedi_device *dev, struct comedi_subdevice * s)
 122 {
 123         short d;
 124
 125         d = CALLBACK_FUNC(0, _8255_DATA, 0, CALLBACK_ARG);
 126         d |= (CALLBACK_FUNC(0, _8255_DATA + 1, 0, CALLBACK_ARG) << 8);
 127
 128         comedi_buf_put(s->async, d);
 129         s->async->events |= COMEDI_CB_EOS;
 130
 131         comedi_event(dev, s);
 132 }
 133
 134 static int subdev_8255_cb(int dir, int port, int data, unsigned long arg)
 135 {
 136         unsigned long iobase = arg;
 137
 138         if (dir) {
 139                 outb(data, iobase + port);
 140                 return 0;
 141         } else {
 142                 return inb(iobase + port);
 143         }
 144 }
 145
 146 static int subdev_8255_insn(struct comedi_device *dev, struct comedi_subdevice * s,
 147         struct comedi_insn * insn, unsigned int * data)
 148 {
 149         if (data[0]) {
 150                 s->state &= ~data[0];
 151                 s->state |= (data[0] & data[1]);
 152
 153                 if (data[0] & 0xff)
 154                         CALLBACK_FUNC(1, _8255_DATA, s->state & 0xff,
 155                                 CALLBACK_ARG);
 156                 if (data[0] & 0xff00)
 157                         CALLBACK_FUNC(1, _8255_DATA + 1, (s->state >> 8) & 0xff,
 158                                 CALLBACK_ARG);
 159                 if (data[0] & 0xff0000)
 160                         CALLBACK_FUNC(1, _8255_DATA + 2,
 161                                 (s->state >> 16) & 0xff, CALLBACK_ARG);
 162         }
 163
 164         data[1] = CALLBACK_FUNC(0, _8255_DATA, 0, CALLBACK_ARG);
 165         data[1] |= (CALLBACK_FUNC(0, _8255_DATA + 1, 0, CALLBACK_ARG) << 8);
 166         data[1] |= (CALLBACK_FUNC(0, _8255_DATA + 2, 0, CALLBACK_ARG) << 16);
 167
 168         return 2;
 169 }
 170
 171 static int subdev_8255_insn_config(struct comedi_device *dev, struct comedi_subdevice * s,
 172         struct comedi_insn * insn, unsigned int * data)
 173 {
 174         unsigned int mask;
 175         unsigned int bits;
 176
 177         mask = 1 << CR_CHAN(insn->chanspec);
 178         if (mask & 0x0000ff) {
 179                 bits = 0x0000ff;
 180         } else if (mask & 0x00ff00) {
 181                 bits = 0x00ff00;
 182         } else if (mask & 0x0f0000) {
 183                 bits = 0x0f0000;
 184         } else {
 185                 bits = 0xf00000;
 186         }
 187
 188         switch (data[0]) {
 189         case INSN_CONFIG_DIO_INPUT:
 190                 s->io_bits &= ~bits;
 191                 break;
 192         case INSN_CONFIG_DIO_OUTPUT:
 193                 s->io_bits |= bits;
 194                 break;
 195         case INSN_CONFIG_DIO_QUERY:
 196                 data[1] = (s->io_bits & bits) ? COMEDI_OUTPUT : COMEDI_INPUT;
 197                 return insn->n;
 198                 break;
 199         default:
 200                 return -EINVAL;
 201         }
 202
 203         do_config(dev, s);
 204
 205         return 1;
 206 }
 207
 208 static void do_config(struct comedi_device *dev, struct comedi_subdevice * s)
 209 {
 210         int config;
 211
 212         config = CR_CW;
 213         /* 1 in io_bits indicates output, 1 in config indicates input */
 214         if (!(s->io_bits & 0x0000ff))
 215                 config |= CR_A_IO;
 216         if (!(s->io_bits & 0x00ff00))
 217                 config |= CR_B_IO;
 218         if (!(s->io_bits & 0x0f0000))
 219                 config |= CR_C_LO_IO;
 220         if (!(s->io_bits & 0xf00000))
 221                 config |= CR_C_HI_IO;
 222         CALLBACK_FUNC(1, _8255_CR, config, CALLBACK_ARG);
 223 }
 224
 225 static int subdev_8255_cmdtest(struct comedi_device *dev, struct comedi_subdevice * s,
 226         struct comedi_cmd * cmd)
 227 {
 228         int err = 0;
 229         unsigned int tmp;
 230
 231         /* step 1 */
 232
 233         tmp = cmd->start_src;
 234         cmd->start_src &= TRIG_NOW;
 235         if (!cmd->start_src || tmp != cmd->start_src)
 236                 err++;
 237
 238         tmp = cmd->scan_begin_src;
 239         cmd->scan_begin_src &= TRIG_EXT;
 240         if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
 241                 err++;
 242
 243         tmp = cmd->convert_src;
 244         cmd->convert_src &= TRIG_FOLLOW;
 245         if (!cmd->convert_src || tmp != cmd->convert_src)
 246                 err++;
 247
 248         tmp = cmd->scan_end_src;
 249         cmd->scan_end_src &= TRIG_COUNT;
 250         if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
 251                 err++;
 252
 253         tmp = cmd->stop_src;
 254         cmd->stop_src &= TRIG_NONE;
 255         if (!cmd->stop_src || tmp != cmd->stop_src)
 256                 err++;
 257
 258         if (err)
 259                 return 1;
 260
 261         /* step 2 */
 262
 263         if (err)
 264                 return 2;
 265
 266         /* step 3 */
 267
 268         if (cmd->start_arg != 0) {
 269                 cmd->start_arg = 0;
 270                 err++;
 271         }
 272         if (cmd->scan_begin_arg != 0) {
 273                 cmd->scan_begin_arg = 0;
 274                 err++;
 275         }
 276         if (cmd->convert_arg != 0) {
 277                 cmd->convert_arg = 0;
 278                 err++;
 279         }
 280         if (cmd->scan_end_arg != 1) {
 281                 cmd->scan_end_arg = 1;
 282                 err++;
 283         }
 284         if (cmd->stop_arg != 0) {
 285                 cmd->stop_arg = 0;
 286                 err++;
 287         }
 288
 289         if (err)
 290                 return 3;
 291
 292         /* step 4 */
 293
 294         if (err)
 295                 return 4;
 296
 297         return 0;
 298 }
 299
 300 static int subdev_8255_cmd(struct comedi_device *dev, struct comedi_subdevice * s)
 301 {
 302         /* FIXME */
 303
 304         return 0;
 305 }
 306
 307 static int subdev_8255_cancel(struct comedi_device *dev, struct comedi_subdevice * s)
 308 {
 309         /* FIXME */
 310
 311         return 0;
 312 }
 313
 314 int subdev_8255_init(struct comedi_device *dev, struct comedi_subdevice * s, int (*cb) (int,
 315                 int, int, unsigned long), unsigned long arg)
 316 {
 317         s->type = COMEDI_SUBD_DIO;
 318         s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
 319         s->n_chan = 24;
 320         s->range_table = &range_digital;
 321         s->maxdata = 1;
 322
 323         s->private = kmalloc(sizeof(struct subdev_8255_struct), GFP_KERNEL);
 324         if (!s->private)
 325                 return -ENOMEM;
 326
 327         CALLBACK_ARG = arg;
 328         if (cb == NULL) {
 329                 CALLBACK_FUNC = subdev_8255_cb;
 330         } else {
 331                 CALLBACK_FUNC = cb;
 332         }
 333         s->insn_bits = subdev_8255_insn;
 334         s->insn_config = subdev_8255_insn_config;
 335
 336         s->state = 0;
 337         s->io_bits = 0;
 338         do_config(dev, s);
 339
 340         return 0;
 341 }
 342
 343 int subdev_8255_init_irq(struct comedi_device *dev, struct comedi_subdevice * s,
 344         int (*cb) (int, int, int, unsigned long), unsigned long arg)
 345 {
 346         int ret;
 347
 348         ret = subdev_8255_init(dev, s, cb, arg);
 349         if (ret < 0)
 350                 return ret;
 351
 352         s->do_cmdtest = subdev_8255_cmdtest;
 353         s->do_cmd = subdev_8255_cmd;
 354         s->cancel = subdev_8255_cancel;
 355
 356         subdevpriv->have_irq = 1;
 357
 358         return 0;
 359 }
 360
 361 void subdev_8255_cleanup(struct comedi_device *dev, struct comedi_subdevice * s)
 362 {
 363         if (s->private) {
 364                 if (subdevpriv->have_irq) {
 365                 }
 366
 367                 kfree(s->private);
 368         }
 369 }
 370
 371 /*
 372
 373    Start of the 8255 standalone device
 374
 375  */
 376
 377 static int dev_8255_attach(struct comedi_device *dev, struct comedi_devconfig * it)
 378 {
 379         int ret;
 380         unsigned long iobase;
 381         int i;
 382
 383         printk("comedi%d: 8255:", dev->minor);
 384
 385         dev->board_name = "8255";
 386
 387         for (i = 0; i < COMEDI_NDEVCONFOPTS; i++) {
 388                 iobase = it->options[i];
 389                 if (!iobase)
 390                         break;
 391         }
 392         if (i == 0) {
 393                 printk(" no devices specified\n");
 394                 return -EINVAL;
 395         }
 396
 397         if ((ret = alloc_subdevices(dev, i)) < 0)
 398                 return ret;
 399
 400         for (i = 0; i < dev->n_subdevices; i++) {
 401                 iobase = it->options[i];
 402
 403                 printk(" 0x%04lx", iobase);
 404                 if (!request_region(iobase, _8255_SIZE, "8255")) {
 405                         printk(" (I/O port conflict)");
 406
 407                         dev->subdevices[i].type = COMEDI_SUBD_UNUSED;
 408                 } else {
 409                         subdev_8255_init(dev, dev->subdevices + i, NULL,
 410                                 iobase);
 411                 }
 412         }
 413
 414         printk("\n");
 415
 416         return 0;
 417 }
 418
 419 static int dev_8255_detach(struct comedi_device *dev)
 420 {
 421         int i;
 422         unsigned long iobase;
 423         struct comedi_subdevice *s;
 424
 425         printk("comedi%d: 8255: remove\n", dev->minor);
 426
 427         for (i = 0; i < dev->n_subdevices; i++) {
 428                 s = dev->subdevices + i;
 429                 if (s->type != COMEDI_SUBD_UNUSED) {
 430                         iobase = CALLBACK_ARG;
 431                         release_region(iobase, _8255_SIZE);
 432                 }
 433                 subdev_8255_cleanup(dev, s);
 434         }
 435
 436         return 0;
 437 }
 438
 439 EXPORT_SYMBOL(subdev_8255_init);
 440 EXPORT_SYMBOL(subdev_8255_init_irq);
 441 EXPORT_SYMBOL(subdev_8255_cleanup);
 442 EXPORT_SYMBOL(subdev_8255_interrupt);