root/drivers/staging/comedi/drivers/dt2811.c

DEFINITIONS

1. dt2811_ai_read_sample
2. dt2811_interrupt
3. dt2811_ai_cancel
4. dt2811_ai_set_chanspec
5. dt2811_ai_cmd
6. dt2811_ns_to_timer
7. dt2811_ai_cmdtest
8. dt2811_ai_eoc
9. dt2811_ai_insn_read
10. dt2811_ao_insn_write
11. dt2811_di_insn_bits
12. dt2811_do_insn_bits
13. dt2811_reset
14. dt2811_attach

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Comedi driver for Data Translation DT2811
   4  *
   5  * COMEDI - Linux Control and Measurement Device Interface
   6  * Copyright (C) David A. Schleef <ds@schleef.org>
   7  */
   8 
   9 /*
  10  * Driver: dt2811
  11  * Description: Data Translation DT2811
  12  * Author: ds
  13  * Devices: [Data Translation] DT2811-PGL (dt2811-pgl), DT2811-PGH (dt2811-pgh)
  14  * Status: works
  15  *
  16  * Configuration options:
  17  *   [0] - I/O port base address
  18  *   [1] - IRQ (optional, needed for async command support)
  19  *   [2] - A/D reference (# of analog inputs)
  20  *         0 = single-ended (16 channels)
  21  *         1 = differential (8 channels)
  22  *         2 = pseudo-differential (16 channels)
  23  *   [3] - A/D range (deprecated, see below)
  24  *   [4] - D/A 0 range (deprecated, see below)
  25  *   [5] - D/A 1 range (deprecated, see below)
  26  *
  27  * Notes:
  28  *   - A/D ranges are not programmable but the gain is. The AI subdevice has
  29  *     a range_table containing all the possible analog input range/gain
  30  *     options for the dt2811-pgh or dt2811-pgl. Use the range that matches
  31  *     your board configuration and the desired gain to correctly convert
  32  *     between data values and physical units and to set the correct output
  33  *     gain.
  34  *   - D/A ranges are not programmable. The AO subdevice has a range_table
  35  *     containing all the possible analog output ranges. Use the range
  36  *     that matches your board configuration to convert between data
  37  *     values and physical units.
  38  */
  39 
  40 #include <linux/module.h>
  41 #include <linux/interrupt.h>
  42 #include <linux/delay.h>
  43 
  44 #include "../comedidev.h"
  45 
  46 /*
  47  * Register I/O map
  48  */
  49 #define DT2811_ADCSR_REG                0x00    /* r/w  A/D Control/Status */
  50 #define DT2811_ADCSR_ADDONE             BIT(7)  /* r      1=A/D conv done */
  51 #define DT2811_ADCSR_ADERROR            BIT(6)  /* r      1=A/D error */
  52 #define DT2811_ADCSR_ADBUSY             BIT(5)  /* r      1=A/D busy */
  53 #define DT2811_ADCSR_CLRERROR           BIT(4)
  54 #define DT2811_ADCSR_DMAENB             BIT(3)  /* r/w    1=dma ena */
  55 #define DT2811_ADCSR_INTENB             BIT(2)  /* r/w    1=interrupts ena */
  56 #define DT2811_ADCSR_ADMODE(x)          (((x) & 0x3) << 0)
  57 
  58 #define DT2811_ADGCR_REG                0x01    /* r/w  A/D Gain/Channel */
  59 #define DT2811_ADGCR_GAIN(x)            (((x) & 0x3) << 6)
  60 #define DT2811_ADGCR_CHAN(x)            (((x) & 0xf) << 0)
  61 
  62 #define DT2811_ADDATA_LO_REG            0x02    /* r   A/D Data low byte */
  63 #define DT2811_ADDATA_HI_REG            0x03    /* r   A/D Data high byte */
  64 
  65 #define DT2811_DADATA_LO_REG(x)         (0x02 + ((x) * 2)) /* w D/A Data low */
  66 #define DT2811_DADATA_HI_REG(x)         (0x03 + ((x) * 2)) /* w D/A Data high */
  67 
  68 #define DT2811_DI_REG                   0x06    /* r   Digital Input Port 0 */
  69 #define DT2811_DO_REG                   0x06    /* w   Digital Output Port 1 */
  70 
  71 #define DT2811_TMRCTR_REG               0x07    /* r/w  Timer/Counter */
  72 #define DT2811_TMRCTR_MANTISSA(x)       (((x) & 0x7) << 3)
  73 #define DT2811_TMRCTR_EXPONENT(x)       (((x) & 0x7) << 0)
  74 
  75 #define DT2811_OSC_BASE                 1666    /* 600 kHz = 1666.6667ns */
  76 
  77 /*
  78  * Timer frequency control:
  79  *   DT2811_TMRCTR_MANTISSA     DT2811_TMRCTR_EXPONENT
  80  *   val  divisor  frequency    val  multiply divisor/divide frequency by
  81  *    0      1      600 kHz      0   1
  82  *    1     10       60 kHz      1   10
  83  *    2      2      300 kHz      2   100
  84  *    3      3      200 kHz      3   1000
  85  *    4      4      150 kHz      4   10000
  86  *    5      5      120 kHz      5   100000
  87  *    6      6      100 kHz      6   1000000
  88  *    7     12       50 kHz      7   10000000
  89  */
  90 static const unsigned int dt2811_clk_dividers[] = {
  91         1, 10, 2, 3, 4, 5, 6, 12
  92 };
  93 
  94 static const unsigned int dt2811_clk_multipliers[] = {
  95         1, 10, 100, 1000, 10000, 100000, 1000000, 10000000
  96 };
  97 
  98 /*
  99  * The Analog Input range is set using jumpers on the board.
 100  *
 101  * Input Range          W9  W10
 102  * -5V to +5V           In  Out
 103  * -2.5V to +2.5V       In  In
 104  * 0V to +5V            Out In
 105  *
 106  * The gain may be set to 1, 2, 4, or 8 (on the dt2811-pgh) or to
 107  * 1, 10, 100, 500 (on the dt2811-pgl).
 108  */
 109 static const struct comedi_lrange dt2811_pgh_ai_ranges = {
 110         12, {
 111                 BIP_RANGE(5),           /* range 0: gain=1 */
 112                 BIP_RANGE(2.5),         /* range 1: gain=2 */
 113                 BIP_RANGE(1.25),        /* range 2: gain=4 */
 114                 BIP_RANGE(0.625),       /* range 3: gain=8 */
 115 
 116                 BIP_RANGE(2.5),         /* range 0+4: gain=1 */
 117                 BIP_RANGE(1.25),        /* range 1+4: gain=2 */
 118                 BIP_RANGE(0.625),       /* range 2+4: gain=4 */
 119                 BIP_RANGE(0.3125),      /* range 3+4: gain=8 */
 120 
 121                 UNI_RANGE(5),           /* range 0+8: gain=1 */
 122                 UNI_RANGE(2.5),         /* range 1+8: gain=2 */
 123                 UNI_RANGE(1.25),        /* range 2+8: gain=4 */
 124                 UNI_RANGE(0.625)        /* range 3+8: gain=8 */
 125         }
 126 };
 127 
 128 static const struct comedi_lrange dt2811_pgl_ai_ranges = {
 129         12, {
 130                 BIP_RANGE(5),           /* range 0: gain=1 */
 131                 BIP_RANGE(0.5),         /* range 1: gain=10 */
 132                 BIP_RANGE(0.05),        /* range 2: gain=100 */
 133                 BIP_RANGE(0.01),        /* range 3: gain=500 */
 134 
 135                 BIP_RANGE(2.5),         /* range 0+4: gain=1 */
 136                 BIP_RANGE(0.25),        /* range 1+4: gain=10 */
 137                 BIP_RANGE(0.025),       /* range 2+4: gain=100 */
 138                 BIP_RANGE(0.005),       /* range 3+4: gain=500 */
 139 
 140                 UNI_RANGE(5),           /* range 0+8: gain=1 */
 141                 UNI_RANGE(0.5),         /* range 1+8: gain=10 */
 142                 UNI_RANGE(0.05),        /* range 2+8: gain=100 */
 143                 UNI_RANGE(0.01)         /* range 3+8: gain=500 */
 144         }
 145 };
 146 
 147 /*
 148  * The Analog Output range is set per-channel using jumpers on the board.
 149  *
 150  *                      DAC0 Jumpers            DAC1 Jumpers
 151  * Output Range         W5  W6  W7  W8          W1  W2  W3  W4
 152  * -5V to +5V           In  Out In  Out         In  Out In  Out
 153  * -2.5V to +2.5V       In  Out Out In          In  Out Out In
 154  * 0 to +5V             Out In  Out In          Out In  Out In
 155  */
 156 static const struct comedi_lrange dt2811_ao_ranges = {
 157         3, {
 158                 BIP_RANGE(5),   /* default setting from factory */
 159                 BIP_RANGE(2.5),
 160                 UNI_RANGE(5)
 161         }
 162 };
 163 
 164 struct dt2811_board {
 165         const char *name;
 166         unsigned int is_pgh:1;
 167 };
 168 
 169 static const struct dt2811_board dt2811_boards[] = {
 170         {
 171                 .name           = "dt2811-pgh",
 172                 .is_pgh         = 1,
 173         }, {
 174                 .name           = "dt2811-pgl",
 175         },
 176 };
 177 
 178 struct dt2811_private {
 179         unsigned int ai_divisor;
 180 };
 181 
 182 static unsigned int dt2811_ai_read_sample(struct comedi_device *dev,
 183                                           struct comedi_subdevice *s)
 184 {
 185         unsigned int val;
 186 
 187         val = inb(dev->iobase + DT2811_ADDATA_LO_REG) |
 188               (inb(dev->iobase + DT2811_ADDATA_HI_REG) << 8);
 189 
 190         return val & s->maxdata;
 191 }
 192 
 193 static irqreturn_t dt2811_interrupt(int irq, void *d)
 194 {
 195         struct comedi_device *dev = d;
 196         struct comedi_subdevice *s = dev->read_subdev;
 197         struct comedi_async *async = s->async;
 198         struct comedi_cmd *cmd = &async->cmd;
 199         unsigned int status;
 200 
 201         if (!dev->attached)
 202                 return IRQ_NONE;
 203 
 204         status = inb(dev->iobase + DT2811_ADCSR_REG);
 205 
 206         if (status & DT2811_ADCSR_ADERROR) {
 207                 async->events |= COMEDI_CB_OVERFLOW;
 208 
 209                 outb(status | DT2811_ADCSR_CLRERROR,
 210                      dev->iobase + DT2811_ADCSR_REG);
 211         }
 212 
 213         if (status & DT2811_ADCSR_ADDONE) {
 214                 unsigned short val;
 215 
 216                 val = dt2811_ai_read_sample(dev, s);
 217                 comedi_buf_write_samples(s, &val, 1);
 218         }
 219 
 220         if (cmd->stop_src == TRIG_COUNT && async->scans_done >= cmd->stop_arg)
 221                 async->events |= COMEDI_CB_EOA;
 222 
 223         comedi_handle_events(dev, s);
 224 
 225         return IRQ_HANDLED;
 226 }
 227 
 228 static int dt2811_ai_cancel(struct comedi_device *dev,
 229                             struct comedi_subdevice *s)
 230 {
 231         /*
 232          * Mode 0
 233          * Single conversion
 234          *
 235          * Loading a chanspec will trigger a conversion.
 236          */
 237         outb(DT2811_ADCSR_ADMODE(0), dev->iobase + DT2811_ADCSR_REG);
 238 
 239         return 0;
 240 }
 241 
 242 static void dt2811_ai_set_chanspec(struct comedi_device *dev,
 243                                    unsigned int chanspec)
 244 {
 245         unsigned int chan = CR_CHAN(chanspec);
 246         unsigned int range = CR_RANGE(chanspec);
 247 
 248         outb(DT2811_ADGCR_CHAN(chan) | DT2811_ADGCR_GAIN(range),
 249              dev->iobase + DT2811_ADGCR_REG);
 250 }
 251 
 252 static int dt2811_ai_cmd(struct comedi_device *dev,
 253                          struct comedi_subdevice *s)
 254 {
 255         struct dt2811_private *devpriv = dev->private;
 256         struct comedi_cmd *cmd = &s->async->cmd;
 257         unsigned int mode;
 258 
 259         if (cmd->start_src == TRIG_NOW) {
 260                 /*
 261                  * Mode 1
 262                  * Continuous conversion, internal trigger and clock
 263                  *
 264                  * This resets the trigger flip-flop, disabling A/D strobes.
 265                  * The timer/counter register is loaded with the division
 266                  * ratio which will give the required sample rate.
 267                  *
 268                  * Loading the first chanspec sets the trigger flip-flop,
 269                  * enabling the timer/counter. A/D strobes are then generated
 270                  * at the rate set by the internal clock/divider.
 271                  */
 272                 mode = DT2811_ADCSR_ADMODE(1);
 273         } else { /* TRIG_EXT */
 274                 if (cmd->convert_src == TRIG_TIMER) {
 275                         /*
 276                          * Mode 2
 277                          * Continuous conversion, external trigger
 278                          *
 279                          * Similar to Mode 1, with the exception that the
 280                          * trigger flip-flop must be set by a negative edge
 281                          * on the external trigger input.
 282                          */
 283                         mode = DT2811_ADCSR_ADMODE(2);
 284                 } else { /* TRIG_EXT */
 285                         /*
 286                          * Mode 3
 287                          * Continuous conversion, external trigger, clock
 288                          *
 289                          * Similar to Mode 2, with the exception that the
 290                          * conversion rate is set by the frequency on the
 291                          * external clock/divider.
 292                          */
 293                         mode = DT2811_ADCSR_ADMODE(3);
 294                 }
 295         }
 296         outb(mode | DT2811_ADCSR_INTENB, dev->iobase + DT2811_ADCSR_REG);
 297 
 298         /* load timer */
 299         outb(devpriv->ai_divisor, dev->iobase + DT2811_TMRCTR_REG);
 300 
 301         /* load chanspec - enables timer */
 302         dt2811_ai_set_chanspec(dev, cmd->chanlist[0]);
 303 
 304         return 0;
 305 }
 306 
 307 static unsigned int dt2811_ns_to_timer(unsigned int *nanosec,
 308                                        unsigned int flags)
 309 {
 310         unsigned long long ns;
 311         unsigned int ns_lo = COMEDI_MIN_SPEED;
 312         unsigned int ns_hi = 0;
 313         unsigned int divisor_hi = 0;
 314         unsigned int divisor_lo = 0;
 315         unsigned int _div;
 316         unsigned int _mult;
 317 
 318         /*
 319          * Work through all the divider/multiplier values to find the two
 320          * closest divisors to generate the requested nanosecond timing.
 321          */
 322         for (_div = 0; _div <= 7; _div++) {
 323                 for (_mult = 0; _mult <= 7; _mult++) {
 324                         unsigned int div = dt2811_clk_dividers[_div];
 325                         unsigned int mult = dt2811_clk_multipliers[_mult];
 326                         unsigned long long divider = div * mult;
 327                         unsigned int divisor = DT2811_TMRCTR_MANTISSA(_div) |
 328                                                DT2811_TMRCTR_EXPONENT(_mult);
 329 
 330                         /*
 331                          * The timer can be configured to run at a slowest
 332                          * speed of 0.005hz (600 Khz/120000000), which requires
 333                          * 37-bits to represent the nanosecond value. Limit the
 334                          * slowest timing to what comedi handles (32-bits).
 335                          */
 336                         ns = divider * DT2811_OSC_BASE;
 337                         if (ns > COMEDI_MIN_SPEED)
 338                                 continue;
 339 
 340                         /* Check for fastest found timing */
 341                         if (ns <= *nanosec && ns > ns_hi) {
 342                                 ns_hi = ns;
 343                                 divisor_hi = divisor;
 344                         }
 345                         /* Check for slowest found timing */
 346                         if (ns >= *nanosec && ns < ns_lo) {
 347                                 ns_lo = ns;
 348                                 divisor_lo = divisor;
 349                         }
 350                 }
 351         }
 352 
 353         /*
 354          * The slowest found timing will be invalid if the requested timing
 355          * is faster than what can be generated by the timer. Fix it so that
 356          * CMDF_ROUND_UP returns valid timing.
 357          */
 358         if (ns_lo == COMEDI_MIN_SPEED) {
 359                 ns_lo = ns_hi;
 360                 divisor_lo = divisor_hi;
 361         }
 362         /*
 363          * The fastest found timing will be invalid if the requested timing
 364          * is less than what can be generated by the timer. Fix it so that
 365          * CMDF_ROUND_NEAREST and CMDF_ROUND_DOWN return valid timing.
 366          */
 367         if (ns_hi == 0) {
 368                 ns_hi = ns_lo;
 369                 divisor_hi = divisor_lo;
 370         }
 371 
 372         switch (flags & CMDF_ROUND_MASK) {
 373         case CMDF_ROUND_NEAREST:
 374         default:
 375                 if (ns_hi - *nanosec < *nanosec - ns_lo) {
 376                         *nanosec = ns_lo;
 377                         return divisor_lo;
 378                 }
 379                 *nanosec = ns_hi;
 380                 return divisor_hi;
 381         case CMDF_ROUND_UP:
 382                 *nanosec = ns_lo;
 383                 return divisor_lo;
 384         case CMDF_ROUND_DOWN:
 385                 *nanosec = ns_hi;
 386                 return divisor_hi;
 387         }
 388 }
 389 
 390 static int dt2811_ai_cmdtest(struct comedi_device *dev,
 391                              struct comedi_subdevice *s,
 392                              struct comedi_cmd *cmd)
 393 {
 394         struct dt2811_private *devpriv = dev->private;
 395         unsigned int arg;
 396         int err = 0;
 397 
 398         /* Step 1 : check if triggers are trivially valid */
 399 
 400         err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_EXT);
 401         err |= comedi_check_trigger_src(&cmd->scan_begin_src, TRIG_FOLLOW);
 402         err |= comedi_check_trigger_src(&cmd->convert_src,
 403                                         TRIG_TIMER | TRIG_EXT);
 404         err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
 405         err |= comedi_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 406 
 407         if (err)
 408                 return 1;
 409 
 410         /* Step 2a : make sure trigger sources are unique */
 411 
 412         err |= comedi_check_trigger_is_unique(cmd->start_src);
 413         err |= comedi_check_trigger_is_unique(cmd->convert_src);
 414         err |= comedi_check_trigger_is_unique(cmd->stop_src);
 415 
 416         /* Step 2b : and mutually compatible */
 417 
 418         if (cmd->convert_src == TRIG_EXT && cmd->start_src != TRIG_EXT)
 419                 err |= -EINVAL;
 420 
 421         if (err)
 422                 return 2;
 423 
 424         /* Step 3: check if arguments are trivially valid */
 425 
 426         err |= comedi_check_trigger_arg_is(&cmd->start_arg, 0);
 427         err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
 428         if (cmd->convert_src == TRIG_TIMER)
 429                 err |= comedi_check_trigger_arg_min(&cmd->convert_arg, 12500);
 430         err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg,
 431                                            cmd->chanlist_len);
 432         if (cmd->stop_src == TRIG_COUNT)
 433                 err |= comedi_check_trigger_arg_min(&cmd->stop_arg, 1);
 434         else    /* TRIG_NONE */
 435                 err |= comedi_check_trigger_arg_is(&cmd->stop_arg, 0);
 436 
 437         if (err)
 438                 return 3;
 439 
 440         /* Step 4: fix up any arguments */
 441 
 442         if (cmd->convert_src == TRIG_TIMER) {
 443                 arg = cmd->convert_arg;
 444                 devpriv->ai_divisor = dt2811_ns_to_timer(&arg, cmd->flags);
 445                 err |= comedi_check_trigger_arg_is(&cmd->convert_arg, arg);
 446         } else { /* TRIG_EXT */
 447                 /* The convert_arg is used to set the divisor. */
 448                 devpriv->ai_divisor = cmd->convert_arg;
 449         }
 450 
 451         if (err)
 452                 return 4;
 453 
 454         /* Step 5: check channel list if it exists */
 455 
 456         return 0;
 457 }
 458 
 459 static int dt2811_ai_eoc(struct comedi_device *dev,
 460                          struct comedi_subdevice *s,
 461                          struct comedi_insn *insn,
 462                          unsigned long context)
 463 {
 464         unsigned int status;
 465 
 466         status = inb(dev->iobase + DT2811_ADCSR_REG);
 467         if ((status & DT2811_ADCSR_ADBUSY) == 0)
 468                 return 0;
 469         return -EBUSY;
 470 }
 471 
 472 static int dt2811_ai_insn_read(struct comedi_device *dev,
 473                                struct comedi_subdevice *s,
 474                                struct comedi_insn *insn,
 475                                unsigned int *data)
 476 {
 477         int ret;
 478         int i;
 479 
 480         /* We will already be in Mode 0 */
 481         for (i = 0; i < insn->n; i++) {
 482                 /* load chanspec and trigger conversion */
 483                 dt2811_ai_set_chanspec(dev, insn->chanspec);
 484 
 485                 ret = comedi_timeout(dev, s, insn, dt2811_ai_eoc, 0);
 486                 if (ret)
 487                         return ret;
 488 
 489                 data[i] = dt2811_ai_read_sample(dev, s);
 490         }
 491 
 492         return insn->n;
 493 }
 494 
 495 static int dt2811_ao_insn_write(struct comedi_device *dev,
 496                                 struct comedi_subdevice *s,
 497                                 struct comedi_insn *insn,
 498                                 unsigned int *data)
 499 {
 500         unsigned int chan = CR_CHAN(insn->chanspec);
 501         unsigned int val = s->readback[chan];
 502         int i;
 503 
 504         for (i = 0; i < insn->n; i++) {
 505                 val = data[i];
 506                 outb(val & 0xff, dev->iobase + DT2811_DADATA_LO_REG(chan));
 507                 outb((val >> 8) & 0xff,
 508                      dev->iobase + DT2811_DADATA_HI_REG(chan));
 509         }
 510         s->readback[chan] = val;
 511 
 512         return insn->n;
 513 }
 514 
 515 static int dt2811_di_insn_bits(struct comedi_device *dev,
 516                                struct comedi_subdevice *s,
 517                                struct comedi_insn *insn,
 518                                unsigned int *data)
 519 {
 520         data[1] = inb(dev->iobase + DT2811_DI_REG);
 521 
 522         return insn->n;
 523 }
 524 
 525 static int dt2811_do_insn_bits(struct comedi_device *dev,
 526                                struct comedi_subdevice *s,
 527                                struct comedi_insn *insn,
 528                                unsigned int *data)
 529 {
 530         if (comedi_dio_update_state(s, data))
 531                 outb(s->state, dev->iobase + DT2811_DO_REG);
 532 
 533         data[1] = s->state;
 534 
 535         return insn->n;
 536 }
 537 
 538 static void dt2811_reset(struct comedi_device *dev)
 539 {
 540         /* This is the initialization sequence from the users manual */
 541         outb(DT2811_ADCSR_ADMODE(0), dev->iobase + DT2811_ADCSR_REG);
 542         usleep_range(100, 1000);
 543         inb(dev->iobase + DT2811_ADDATA_LO_REG);
 544         inb(dev->iobase + DT2811_ADDATA_HI_REG);
 545         outb(DT2811_ADCSR_ADMODE(0) | DT2811_ADCSR_CLRERROR,
 546              dev->iobase + DT2811_ADCSR_REG);
 547 }
 548 
 549 static int dt2811_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 550 {
 551         const struct dt2811_board *board = dev->board_ptr;
 552         struct dt2811_private *devpriv;
 553         struct comedi_subdevice *s;
 554         int ret;
 555 
 556         devpriv = comedi_alloc_devpriv(dev, sizeof(*devpriv));
 557         if (!devpriv)
 558                 return -ENOMEM;
 559 
 560         ret = comedi_request_region(dev, it->options[0], 0x8);
 561         if (ret)
 562                 return ret;
 563 
 564         dt2811_reset(dev);
 565 
 566         /* IRQ's 2,3,5,7 are valid for async command support */
 567         if (it->options[1] <= 7  && (BIT(it->options[1]) & 0xac)) {
 568                 ret = request_irq(it->options[1], dt2811_interrupt, 0,
 569                                   dev->board_name, dev);
 570                 if (ret == 0)
 571                         dev->irq = it->options[1];
 572         }
 573 
 574         ret = comedi_alloc_subdevices(dev, 4);
 575         if (ret)
 576                 return ret;
 577 
 578         /* Analog Input subdevice */
 579         s = &dev->subdevices[0];
 580         s->type         = COMEDI_SUBD_AI;
 581         s->subdev_flags = SDF_READABLE |
 582                           ((it->options[2] == 1) ? SDF_DIFF :
 583                            (it->options[2] == 2) ? SDF_COMMON : SDF_GROUND);
 584         s->n_chan       = (it->options[2] == 1) ? 8 : 16;
 585         s->maxdata      = 0x0fff;
 586         s->range_table  = board->is_pgh ? &dt2811_pgh_ai_ranges
 587                                         : &dt2811_pgl_ai_ranges;
 588         s->insn_read    = dt2811_ai_insn_read;
 589         if (dev->irq) {
 590                 dev->read_subdev = s;
 591                 s->subdev_flags |= SDF_CMD_READ;
 592                 s->len_chanlist = 1;
 593                 s->do_cmdtest   = dt2811_ai_cmdtest;
 594                 s->do_cmd       = dt2811_ai_cmd;
 595                 s->cancel       = dt2811_ai_cancel;
 596         }
 597 
 598         /* Analog Output subdevice */
 599         s = &dev->subdevices[1];
 600         s->type         = COMEDI_SUBD_AO;
 601         s->subdev_flags = SDF_WRITABLE;
 602         s->n_chan       = 2;
 603         s->maxdata      = 0x0fff;
 604         s->range_table  = &dt2811_ao_ranges;
 605         s->insn_write   = dt2811_ao_insn_write;
 606 
 607         ret = comedi_alloc_subdev_readback(s);
 608         if (ret)
 609                 return ret;
 610 
 611         /* Digital Input subdevice */
 612         s = &dev->subdevices[2];
 613         s->type         = COMEDI_SUBD_DI;
 614         s->subdev_flags = SDF_READABLE;
 615         s->n_chan       = 8;
 616         s->maxdata      = 1;
 617         s->range_table  = &range_digital;
 618         s->insn_bits    = dt2811_di_insn_bits;
 619 
 620         /* Digital Output subdevice */
 621         s = &dev->subdevices[3];
 622         s->type         = COMEDI_SUBD_DO;
 623         s->subdev_flags = SDF_WRITABLE;
 624         s->n_chan       = 8;
 625         s->maxdata      = 1;
 626         s->range_table  = &range_digital;
 627         s->insn_bits    = dt2811_do_insn_bits;
 628 
 629         return 0;
 630 }
 631 
 632 static struct comedi_driver dt2811_driver = {
 633         .driver_name    = "dt2811",
 634         .module         = THIS_MODULE,
 635         .attach         = dt2811_attach,
 636         .detach         = comedi_legacy_detach,
 637         .board_name     = &dt2811_boards[0].name,
 638         .num_names      = ARRAY_SIZE(dt2811_boards),
 639         .offset         = sizeof(struct dt2811_board),
 640 };
 641 module_comedi_driver(dt2811_driver);
 642 
 643 MODULE_AUTHOR("Comedi http://www.comedi.org");
 644 MODULE_DESCRIPTION("Comedi driver for Data Translation DT2811 series boards");
 645 MODULE_LICENSE("GPL");