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 #include <linux/slab.h>
  85 #include "8255.h"
  86
  87 #define _8255_SIZE 4
  88
  89 #define _8255_DATA 0
  90 #define _8255_CR 3
  91
  92 #define CR_C_LO_IO      0x01
  93 #define CR_B_IO         0x02
  94 #define CR_B_MODE       0x04
  95 #define CR_C_HI_IO      0x08
  96 #define CR_A_IO         0x10
  97 #define CR_A_MODE(a)    ((a)<<5)
  98 #define CR_CW           0x80
  99
 100 struct subdev_8255_struct {
 101         unsigned long cb_arg;
 102         int (*cb_func) (int, int, int, unsigned long);
 103         int have_irq;
 104 };
 105
 106 #define CALLBACK_ARG    (((struct subdev_8255_struct *)s->private)->cb_arg)
 107 #define CALLBACK_FUNC   (((struct subdev_8255_struct *)s->private)->cb_func)
 108 #define subdevpriv      ((struct subdev_8255_struct *)s->private)
 109
 110 void subdev_8255_interrupt(struct comedi_device *dev,
 111                            struct comedi_subdevice *s)
 112 {
 113         short d;
 114
 115         d = CALLBACK_FUNC(0, _8255_DATA, 0, CALLBACK_ARG);
 116         d |= (CALLBACK_FUNC(0, _8255_DATA + 1, 0, CALLBACK_ARG) << 8);
 117
 118         comedi_buf_put(s->async, d);
 119         s->async->events |= COMEDI_CB_EOS;
 120
 121         comedi_event(dev, s);
 122 }
 123 EXPORT_SYMBOL(subdev_8255_interrupt);
 124
 125 static int subdev_8255_cb(int dir, int port, int data, unsigned long arg)
 126 {
 127         unsigned long iobase = arg;
 128
 129         if (dir) {
 130                 outb(data, iobase + port);
 131                 return 0;
 132         } else {
 133                 return inb(iobase + port);
 134         }
 135 }
 136
 137 static int subdev_8255_insn(struct comedi_device *dev,
 138                             struct comedi_subdevice *s,
 139                             struct comedi_insn *insn, unsigned int *data)
 140 {
 141         if (data[0]) {
 142                 s->state &= ~data[0];
 143                 s->state |= (data[0] & data[1]);
 144
 145                 if (data[0] & 0xff)
 146                         CALLBACK_FUNC(1, _8255_DATA, s->state & 0xff,
 147                                       CALLBACK_ARG);
 148                 if (data[0] & 0xff00)
 149                         CALLBACK_FUNC(1, _8255_DATA + 1, (s->state >> 8) & 0xff,
 150                                       CALLBACK_ARG);
 151                 if (data[0] & 0xff0000)
 152                         CALLBACK_FUNC(1, _8255_DATA + 2,
 153                                       (s->state >> 16) & 0xff, CALLBACK_ARG);
 154         }
 155
 156         data[1] = CALLBACK_FUNC(0, _8255_DATA, 0, CALLBACK_ARG);
 157         data[1] |= (CALLBACK_FUNC(0, _8255_DATA + 1, 0, CALLBACK_ARG) << 8);
 158         data[1] |= (CALLBACK_FUNC(0, _8255_DATA + 2, 0, CALLBACK_ARG) << 16);
 159
 160         return 2;
 161 }
 162
 163 static void do_config(struct comedi_device *dev, struct comedi_subdevice *s)
 164 {
 165         int config;
 166
 167         config = CR_CW;
 168         /* 1 in io_bits indicates output, 1 in config indicates input */
 169         if (!(s->io_bits & 0x0000ff))
 170                 config |= CR_A_IO;
 171         if (!(s->io_bits & 0x00ff00))
 172                 config |= CR_B_IO;
 173         if (!(s->io_bits & 0x0f0000))
 174                 config |= CR_C_LO_IO;
 175         if (!(s->io_bits & 0xf00000))
 176                 config |= CR_C_HI_IO;
 177         CALLBACK_FUNC(1, _8255_CR, config, CALLBACK_ARG);
 178 }
 179
 180 static int subdev_8255_insn_config(struct comedi_device *dev,
 181                                    struct comedi_subdevice *s,
 182                                    struct comedi_insn *insn, unsigned int *data)
 183 {
 184         unsigned int mask;
 185         unsigned int bits;
 186
 187         mask = 1 << CR_CHAN(insn->chanspec);
 188         if (mask & 0x0000ff)
 189                 bits = 0x0000ff;
 190         else if (mask & 0x00ff00)
 191                 bits = 0x00ff00;
 192         else if (mask & 0x0f0000)
 193                 bits = 0x0f0000;
 194         else
 195                 bits = 0xf00000;
 196
 197         switch (data[0]) {
 198         case INSN_CONFIG_DIO_INPUT:
 199                 s->io_bits &= ~bits;
 200                 break;
 201         case INSN_CONFIG_DIO_OUTPUT:
 202                 s->io_bits |= bits;
 203                 break;
 204         case INSN_CONFIG_DIO_QUERY:
 205                 data[1] = (s->io_bits & bits) ? COMEDI_OUTPUT : COMEDI_INPUT;
 206                 return insn->n;
 207                 break;
 208         default:
 209                 return -EINVAL;
 210         }
 211
 212         do_config(dev, s);
 213
 214         return 1;
 215 }
 216
 217 static int subdev_8255_cmdtest(struct comedi_device *dev,
 218                                struct comedi_subdevice *s,
 219                                struct comedi_cmd *cmd)
 220 {
 221         int err = 0;
 222         unsigned int tmp;
 223
 224         /* step 1 */
 225
 226         tmp = cmd->start_src;
 227         cmd->start_src &= TRIG_NOW;
 228         if (!cmd->start_src || tmp != cmd->start_src)
 229                 err++;
 230
 231         tmp = cmd->scan_begin_src;
 232         cmd->scan_begin_src &= TRIG_EXT;
 233         if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
 234                 err++;
 235
 236         tmp = cmd->convert_src;
 237         cmd->convert_src &= TRIG_FOLLOW;
 238         if (!cmd->convert_src || tmp != cmd->convert_src)
 239                 err++;
 240
 241         tmp = cmd->scan_end_src;
 242         cmd->scan_end_src &= TRIG_COUNT;
 243         if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
 244                 err++;
 245
 246         tmp = cmd->stop_src;
 247         cmd->stop_src &= TRIG_NONE;
 248         if (!cmd->stop_src || tmp != cmd->stop_src)
 249                 err++;
 250
 251         if (err)
 252                 return 1;
 253
 254         /* step 2 */
 255
 256         if (err)
 257                 return 2;
 258
 259         /* step 3 */
 260
 261         if (cmd->start_arg != 0) {
 262                 cmd->start_arg = 0;
 263                 err++;
 264         }
 265         if (cmd->scan_begin_arg != 0) {
 266                 cmd->scan_begin_arg = 0;
 267                 err++;
 268         }
 269         if (cmd->convert_arg != 0) {
 270                 cmd->convert_arg = 0;
 271                 err++;
 272         }
 273         if (cmd->scan_end_arg != 1) {
 274                 cmd->scan_end_arg = 1;
 275                 err++;
 276         }
 277         if (cmd->stop_arg != 0) {
 278                 cmd->stop_arg = 0;
 279                 err++;
 280         }
 281
 282         if (err)
 283                 return 3;
 284
 285         /* step 4 */
 286
 287         if (err)
 288                 return 4;
 289
 290         return 0;
 291 }
 292
 293 static int subdev_8255_cmd(struct comedi_device *dev,
 294                            struct comedi_subdevice *s)
 295 {
 296         /* FIXME */
 297
 298         return 0;
 299 }
 300
 301 static int subdev_8255_cancel(struct comedi_device *dev,
 302                               struct comedi_subdevice *s)
 303 {
 304         /* FIXME */
 305
 306         return 0;
 307 }
 308
 309 int subdev_8255_init(struct comedi_device *dev, struct comedi_subdevice *s,
 310                      int (*cb) (int, int, int, unsigned long),
 311                      unsigned long arg)
 312 {
 313         s->type = COMEDI_SUBD_DIO;
 314         s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
 315         s->n_chan = 24;
 316         s->range_table = &range_digital;
 317         s->maxdata = 1;
 318
 319         s->private = kmalloc(sizeof(struct subdev_8255_struct), GFP_KERNEL);
 320         if (!s->private)
 321                 return -ENOMEM;
 322
 323         CALLBACK_ARG = arg;
 324         if (cb == NULL)
 325                 CALLBACK_FUNC = subdev_8255_cb;
 326         else
 327                 CALLBACK_FUNC = cb;
 328         s->insn_bits = subdev_8255_insn;
 329         s->insn_config = subdev_8255_insn_config;
 330
 331         s->state = 0;
 332         s->io_bits = 0;
 333         do_config(dev, s);
 334
 335         return 0;
 336 }
 337 EXPORT_SYMBOL(subdev_8255_init);
 338
 339 int subdev_8255_init_irq(struct comedi_device *dev, struct comedi_subdevice *s,
 340                          int (*cb) (int, int, int, unsigned long),
 341                          unsigned long arg)
 342 {
 343         int ret;
 344
 345         ret = subdev_8255_init(dev, s, cb, arg);
 346         if (ret < 0)
 347                 return ret;
 348
 349         s->do_cmdtest = subdev_8255_cmdtest;
 350         s->do_cmd = subdev_8255_cmd;
 351         s->cancel = subdev_8255_cancel;
 352
 353         subdevpriv->have_irq = 1;
 354
 355         return 0;
 356 }
 357 EXPORT_SYMBOL(subdev_8255_init_irq);
 358
 359 void subdev_8255_cleanup(struct comedi_device *dev, struct comedi_subdevice *s)
 360 {
 361         kfree(s->private);
 362 }
 363 EXPORT_SYMBOL(subdev_8255_cleanup);
 364
 365 /*
 366
 367    Start of the 8255 standalone device
 368
 369  */
 370
 371 static int dev_8255_attach(struct comedi_device *dev,
 372                            struct comedi_devconfig *it)
 373 {
 374         int ret;
 375         unsigned long iobase;
 376         int i;
 377
 378         dev->board_name = "8255";
 379
 380         for (i = 0; i < COMEDI_NDEVCONFOPTS; i++) {
 381                 iobase = it->options[i];
 382                 if (!iobase)
 383                         break;
 384         }
 385         if (i == 0) {
 386                 printk(KERN_WARNING
 387                        "comedi%d: 8255: no devices specified\n", dev->minor);
 388                 return -EINVAL;
 389         }
 390
 391         ret = comedi_alloc_subdevices(dev, i);
 392         if (ret < 0)
 393                 return ret;
 394
 395         printk(KERN_INFO "comedi%d: 8255:", dev->minor);
 396
 397         for (i = 0; i < dev->n_subdevices; i++) {
 398                 iobase = it->options[i];
 399
 400                 printk(" 0x%04lx", iobase);
 401                 if (!request_region(iobase, _8255_SIZE, "8255")) {
 402                         printk(" (I/O port conflict)");
 403
 404                         dev->subdevices[i].type = COMEDI_SUBD_UNUSED;
 405                 } else {
 406                         subdev_8255_init(dev, dev->subdevices + i, NULL,
 407                                          iobase);
 408                 }
 409         }
 410
 411         printk("\n");
 412
 413         return 0;
 414 }
 415
 416 static void dev_8255_detach(struct comedi_device *dev)
 417 {
 418         int i;
 419         unsigned long iobase;
 420         struct comedi_subdevice *s;
 421
 422         for (i = 0; i < dev->n_subdevices; i++) {
 423                 s = dev->subdevices + i;
 424                 if (s->type != COMEDI_SUBD_UNUSED) {
 425                         iobase = CALLBACK_ARG;
 426                         release_region(iobase, _8255_SIZE);
 427                 }
 428                 subdev_8255_cleanup(dev, s);
 429         }
 430 }
 431
 432 static struct comedi_driver dev_8255_driver = {
 433         .driver_name    = "8255",
 434         .module         = THIS_MODULE,
 435         .attach         = dev_8255_attach,
 436         .detach         = dev_8255_detach,
 437 };
 438 module_comedi_driver(dev_8255_driver);
 439
 440 MODULE_AUTHOR("Comedi http://www.comedi.org");
 441 MODULE_DESCRIPTION("Comedi low-level driver");
 442 MODULE_LICENSE("GPL");