drivers/staging/comedi/drivers/ni_at_a2150.c

   1 /*
   2     comedi/drivers/ni_at_a2150.c
   3     Driver for National Instruments AT-A2150 boards
   4     Copyright (C) 2001, 2002 Frank Mori Hess <fmhess@users.sourceforge.net>
   5
   6     COMEDI - Linux Control and Measurement Device Interface
   7     Copyright (C) 2000 David A. Schleef <ds@schleef.org>
   8
   9     This program is free software; you can redistribute it and/or modify
  10     it under the terms of the GNU General Public License as published by
  11     the Free Software Foundation; either version 2 of the License, or
  12     (at your option) any later version.
  13
  14     This program is distributed in the hope that it will be useful,
  15     but WITHOUT ANY WARRANTY; without even the implied warranty of
  16     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17     GNU General Public License for more details.
  18
  19     You should have received a copy of the GNU General Public License
  20     along with this program; if not, write to the Free Software
  21     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22
  23 ************************************************************************
  24 */
  25 /*
  26 Driver: ni_at_a2150
  27 Description: National Instruments AT-A2150
  28 Author: Frank Mori Hess
  29 Status: works
  30 Devices: [National Instruments] AT-A2150C (at_a2150c), AT-2150S (at_a2150s)
  31
  32 If you want to ac couple the board's inputs, use AREF_OTHER.
  33
  34 Configuration options:
  35   [0] - I/O port base address
  36   [1] - IRQ (optional, required for timed conversions)
  37   [2] - DMA (optional, required for timed conversions)
  38
  39 */
  40 /*
  41 Yet another driver for obsolete hardware brought to you by Frank Hess.
  42 Testing and debugging help provided by Dave Andruczyk.
  43
  44 This driver supports the boards:
  45
  46 AT-A2150C
  47 AT-A2150S
  48
  49 The only difference is their master clock frequencies.
  50
  51 Options:
  52         [0] - base io address
  53         [1] - irq
  54         [2] - dma channel
  55
  56 References (from ftp://ftp.natinst.com/support/manuals):
  57
  58            320360.pdf  AT-A2150 User Manual
  59
  60 TODO:
  61
  62 analog level triggering
  63 TRIG_WAKE_EOS
  64
  65 */
  66
  67 #include <linux/interrupt.h>
  68 #include <linux/slab.h>
  69 #include "../comedidev.h"
  70
  71 #include <linux/ioport.h>
  72 #include <linux/io.h>
  73 #include <asm/dma.h>
  74
  75 #include "8253.h"
  76 #include "comedi_fc.h"
  77
  78 #define A2150_SIZE           28
  79 #define A2150_DMA_BUFFER_SIZE   0xff00  /*  size in bytes of dma buffer */
  80
  81 /* #define A2150_DEBUG     enable debugging code */
  82 #undef A2150_DEBUG              /*  disable debugging code */
  83
  84 /* Registers and bits */
  85 #define CONFIG_REG              0x0
  86 #define   CHANNEL_BITS(x)               ((x) & 0x7)
  87 #define   CHANNEL_MASK          0x7
  88 #define   CLOCK_SELECT_BITS(x)          (((x) & 0x3) << 3)
  89 #define   CLOCK_DIVISOR_BITS(x)         (((x) & 0x3) << 5)
  90 #define   CLOCK_MASK            (0xf << 3)
  91 #define   ENABLE0_BIT           0x80    /*  enable (don't internally ground) channels 0 and 1 */
  92 #define   ENABLE1_BIT           0x100   /*  enable (don't internally ground) channels 2 and 3 */
  93 #define   AC0_BIT               0x200   /*  ac couple channels 0,1 */
  94 #define   AC1_BIT               0x400   /*  ac couple channels 2,3 */
  95 #define   APD_BIT               0x800   /*  analog power down */
  96 #define   DPD_BIT               0x1000  /*  digital power down */
  97 #define TRIGGER_REG             0x2     /*  trigger config register */
  98 #define   POST_TRIGGER_BITS             0x2
  99 #define   DELAY_TRIGGER_BITS            0x3
 100 #define   HW_TRIG_EN            0x10    /*  enable hardware trigger */
 101 #define FIFO_START_REG          0x6     /*  software start aquistion trigger */
 102 #define FIFO_RESET_REG          0x8     /*  clears fifo + fifo flags */
 103 #define FIFO_DATA_REG           0xa     /*  read data */
 104 #define DMA_TC_CLEAR_REG                0xe     /*  clear dma terminal count interrupt */
 105 #define STATUS_REG              0x12    /*  read only */
 106 #define   FNE_BIT               0x1     /*  fifo not empty */
 107 #define   OVFL_BIT              0x8     /*  fifo overflow */
 108 #define   EDAQ_BIT              0x10    /*  end of acquisition interrupt */
 109 #define   DCAL_BIT              0x20    /*  offset calibration in progress */
 110 #define   INTR_BIT              0x40    /*  interrupt has occurred */
 111 #define   DMA_TC_BIT            0x80    /*  dma terminal count interrupt has occurred */
 112 #define   ID_BITS(x)    (((x) >> 8) & 0x3)
 113 #define IRQ_DMA_CNTRL_REG               0x12    /*  write only */
 114 #define   DMA_CHAN_BITS(x)              ((x) & 0x7)     /*  sets dma channel */
 115 #define   DMA_EN_BIT            0x8     /*  enables dma */
 116 #define   IRQ_LVL_BITS(x)               (((x) & 0xf) << 4)      /*  sets irq level */
 117 #define   FIFO_INTR_EN_BIT              0x100   /*  enable fifo interrupts */
 118 #define   FIFO_INTR_FHF_BIT             0x200   /*  interrupt fifo half full */
 119 #define   DMA_INTR_EN_BIT               0x800   /*  enable interrupt on dma terminal count */
 120 #define   DMA_DEM_EN_BIT        0x1000  /*  enables demand mode dma */
 121 #define I8253_BASE_REG          0x14
 122 #define I8253_MODE_REG          0x17
 123 #define   HW_COUNT_DISABLE              0x30    /*  disable hardware counting of conversions */
 124
 125 struct a2150_board {
 126         const char *name;
 127         int clock[4];           /*  master clock periods, in nanoseconds */
 128         int num_clocks;         /*  number of available master clock speeds */
 129         int ai_speed;           /*  maximum conversion rate in nanoseconds */
 130 };
 131
 132 /* analog input range */
 133 static const struct comedi_lrange range_a2150 = {
 134         1,
 135         {
 136          RANGE(-2.828, 2.828),
 137          }
 138 };
 139
 140 /* enum must match board indices */
 141 enum { a2150_c, a2150_s };
 142 static const struct a2150_board a2150_boards[] = {
 143         {
 144          .name = "at-a2150c",
 145          .clock = {31250, 22676, 20833, 19531},
 146          .num_clocks = 4,
 147          .ai_speed = 19531,
 148          },
 149         {
 150          .name = "at-a2150s",
 151          .clock = {62500, 50000, 41667, 0},
 152          .num_clocks = 3,
 153          .ai_speed = 41667,
 154          },
 155 };
 156
 157 /*
 158  * Useful for shorthand access to the particular board structure
 159  */
 160 #define thisboard ((const struct a2150_board *)dev->board_ptr)
 161
 162 struct a2150_private {
 163
 164         volatile unsigned int count;    /* number of data points left to be taken */
 165         unsigned int dma;       /*  dma channel */
 166         s16 *dma_buffer;        /*  dma buffer */
 167         unsigned int dma_transfer_size; /*  size in bytes of dma transfers */
 168         int irq_dma_bits;       /*  irq/dma register bits */
 169         int config_bits;        /*  config register bits */
 170 };
 171
 172 #define devpriv ((struct a2150_private *)dev->private)
 173
 174 static int a2150_attach(struct comedi_device *dev, struct comedi_devconfig *it);
 175 static int a2150_detach(struct comedi_device *dev);
 176 static int a2150_cancel(struct comedi_device *dev, struct comedi_subdevice *s);
 177
 178 static struct comedi_driver driver_a2150 = {
 179         .driver_name = "ni_at_a2150",
 180         .module = THIS_MODULE,
 181         .attach = a2150_attach,
 182         .detach = a2150_detach,
 183 };
 184
 185 static irqreturn_t a2150_interrupt(int irq, void *d);
 186 static int a2150_ai_cmdtest(struct comedi_device *dev,
 187                             struct comedi_subdevice *s, struct comedi_cmd *cmd);
 188 static int a2150_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s);
 189 static int a2150_ai_rinsn(struct comedi_device *dev, struct comedi_subdevice *s,
 190                           struct comedi_insn *insn, unsigned int *data);
 191 static int a2150_get_timing(struct comedi_device *dev, unsigned int *period,
 192                             int flags);
 193 static int a2150_probe(struct comedi_device *dev);
 194 static int a2150_set_chanlist(struct comedi_device *dev,
 195                               unsigned int start_channel,
 196                               unsigned int num_channels);
 197 /*
 198  * A convenient macro that defines init_module() and cleanup_module(),
 199  * as necessary.
 200  */
 201 static int __init driver_a2150_init_module(void)
 202 {
 203         return comedi_driver_register(&driver_a2150);
 204 }
 205
 206 static void __exit driver_a2150_cleanup_module(void)
 207 {
 208         comedi_driver_unregister(&driver_a2150);
 209 }
 210
 211 module_init(driver_a2150_init_module);
 212 module_exit(driver_a2150_cleanup_module);
 213
 214 #ifdef A2150_DEBUG
 215
 216 static void ni_dump_regs(struct comedi_device *dev)
 217 {
 218         printk("config bits 0x%x\n", devpriv->config_bits);
 219         printk("irq dma bits 0x%x\n", devpriv->irq_dma_bits);
 220         printk("status bits 0x%x\n", inw(dev->iobase + STATUS_REG));
 221 }
 222
 223 #endif
 224
 225 /* interrupt service routine */
 226 static irqreturn_t a2150_interrupt(int irq, void *d)
 227 {
 228         int i;
 229         int status;
 230         unsigned long flags;
 231         struct comedi_device *dev = d;
 232         struct comedi_subdevice *s = dev->read_subdev;
 233         struct comedi_async *async;
 234         struct comedi_cmd *cmd;
 235         unsigned int max_points, num_points, residue, leftover;
 236         short dpnt;
 237         static const int sample_size = sizeof(devpriv->dma_buffer[0]);
 238
 239         if (dev->attached == 0) {
 240                 comedi_error(dev, "premature interrupt");
 241                 return IRQ_HANDLED;
 242         }
 243         /*  initialize async here to make sure s is not NULL */
 244         async = s->async;
 245         async->events = 0;
 246         cmd = &async->cmd;
 247
 248         status = inw(dev->iobase + STATUS_REG);
 249
 250         if ((status & INTR_BIT) == 0) {
 251                 comedi_error(dev, "spurious interrupt");
 252                 return IRQ_NONE;
 253         }
 254
 255         if (status & OVFL_BIT) {
 256                 comedi_error(dev, "fifo overflow");
 257                 a2150_cancel(dev, s);
 258                 async->events |= COMEDI_CB_ERROR | COMEDI_CB_EOA;
 259         }
 260
 261         if ((status & DMA_TC_BIT) == 0) {
 262                 comedi_error(dev, "caught non-dma interrupt?  Aborting.");
 263                 a2150_cancel(dev, s);
 264                 async->events |= COMEDI_CB_ERROR | COMEDI_CB_EOA;
 265                 comedi_event(dev, s);
 266                 return IRQ_HANDLED;
 267         }
 268
 269         flags = claim_dma_lock();
 270         disable_dma(devpriv->dma);
 271         /* clear flip-flop to make sure 2-byte registers for
 272          * count and address get set correctly */
 273         clear_dma_ff(devpriv->dma);
 274
 275         /*  figure out how many points to read */
 276         max_points = devpriv->dma_transfer_size / sample_size;
 277         /* residue is the number of points left to be done on the dma
 278          * transfer.  It should always be zero at this point unless
 279          * the stop_src is set to external triggering.
 280          */
 281         residue = get_dma_residue(devpriv->dma) / sample_size;
 282         num_points = max_points - residue;
 283         if (devpriv->count < num_points && cmd->stop_src == TRIG_COUNT)
 284                 num_points = devpriv->count;
 285
 286         /*  figure out how many points will be stored next time */
 287         leftover = 0;
 288         if (cmd->stop_src == TRIG_NONE) {
 289                 leftover = devpriv->dma_transfer_size / sample_size;
 290         } else if (devpriv->count > max_points) {
 291                 leftover = devpriv->count - max_points;
 292                 if (leftover > max_points)
 293                         leftover = max_points;
 294         }
 295         /* there should only be a residue if collection was stopped by having
 296          * the stop_src set to an external trigger, in which case there
 297          * will be no more data
 298          */
 299         if (residue)
 300                 leftover = 0;
 301
 302         for (i = 0; i < num_points; i++) {
 303                 /* write data point to comedi buffer */
 304                 dpnt = devpriv->dma_buffer[i];
 305                 /*  convert from 2's complement to unsigned coding */
 306                 dpnt ^= 0x8000;
 307                 cfc_write_to_buffer(s, dpnt);
 308                 if (cmd->stop_src == TRIG_COUNT) {
 309                         if (--devpriv->count == 0) {    /* end of acquisition */
 310                                 a2150_cancel(dev, s);
 311                                 async->events |= COMEDI_CB_EOA;
 312                                 break;
 313                         }
 314                 }
 315         }
 316         /*  re-enable  dma */
 317         if (leftover) {
 318                 set_dma_addr(devpriv->dma, virt_to_bus(devpriv->dma_buffer));
 319                 set_dma_count(devpriv->dma, leftover * sample_size);
 320                 enable_dma(devpriv->dma);
 321         }
 322         release_dma_lock(flags);
 323
 324         async->events |= COMEDI_CB_BLOCK;
 325
 326         comedi_event(dev, s);
 327
 328         /* clear interrupt */
 329         outw(0x00, dev->iobase + DMA_TC_CLEAR_REG);
 330
 331         return IRQ_HANDLED;
 332 }
 333
 334 /* probes board type, returns offset */
 335 static int a2150_probe(struct comedi_device *dev)
 336 {
 337         int status = inw(dev->iobase + STATUS_REG);
 338         return ID_BITS(status);
 339 }
 340
 341 static int a2150_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 342 {
 343         struct comedi_subdevice *s;
 344         unsigned long iobase = it->options[0];
 345         unsigned int irq = it->options[1];
 346         unsigned int dma = it->options[2];
 347         static const int timeout = 2000;
 348         int i;
 349
 350         printk("comedi%d: %s: io 0x%lx", dev->minor, driver_a2150.driver_name,
 351                iobase);
 352         if (irq) {
 353                 printk(", irq %u", irq);
 354         } else {
 355                 printk(", no irq");
 356         }
 357         if (dma) {
 358                 printk(", dma %u", dma);
 359         } else {
 360                 printk(", no dma");
 361         }
 362         printk("\n");
 363
 364         /* allocate and initialize dev->private */
 365         if (alloc_private(dev, sizeof(struct a2150_private)) < 0)
 366                 return -ENOMEM;
 367
 368         if (iobase == 0) {
 369                 printk(" io base address required\n");
 370                 return -EINVAL;
 371         }
 372
 373         /* check if io addresses are available */
 374         if (!request_region(iobase, A2150_SIZE, driver_a2150.driver_name)) {
 375                 printk(" I/O port conflict\n");
 376                 return -EIO;
 377         }
 378         dev->iobase = iobase;
 379
 380         /* grab our IRQ */
 381         if (irq) {
 382                 /*  check that irq is supported */
 383                 if (irq < 3 || irq == 8 || irq == 13 || irq > 15) {
 384                         printk(" invalid irq line %u\n", irq);
 385                         return -EINVAL;
 386                 }
 387                 if (request_irq(irq, a2150_interrupt, 0,
 388                                 driver_a2150.driver_name, dev)) {
 389                         printk("unable to allocate irq %u\n", irq);
 390                         return -EINVAL;
 391                 }
 392                 devpriv->irq_dma_bits |= IRQ_LVL_BITS(irq);
 393                 dev->irq = irq;
 394         }
 395         /*  initialize dma */
 396         if (dma) {
 397                 if (dma == 4 || dma > 7) {
 398                         printk(" invalid dma channel %u\n", dma);
 399                         return -EINVAL;
 400                 }
 401                 if (request_dma(dma, driver_a2150.driver_name)) {
 402                         printk(" failed to allocate dma channel %u\n", dma);
 403                         return -EINVAL;
 404                 }
 405                 devpriv->dma = dma;
 406                 devpriv->dma_buffer =
 407                     kmalloc(A2150_DMA_BUFFER_SIZE, GFP_KERNEL | GFP_DMA);
 408                 if (devpriv->dma_buffer == NULL)
 409                         return -ENOMEM;
 410
 411                 disable_dma(dma);
 412                 set_dma_mode(dma, DMA_MODE_READ);
 413
 414                 devpriv->irq_dma_bits |= DMA_CHAN_BITS(dma);
 415         }
 416
 417         dev->board_ptr = a2150_boards + a2150_probe(dev);
 418         dev->board_name = thisboard->name;
 419
 420         if (alloc_subdevices(dev, 1) < 0)
 421                 return -ENOMEM;
 422
 423         /* analog input subdevice */
 424         s = dev->subdevices + 0;
 425         dev->read_subdev = s;
 426         s->type = COMEDI_SUBD_AI;
 427         s->subdev_flags = SDF_READABLE | SDF_GROUND | SDF_OTHER | SDF_CMD_READ;
 428         s->n_chan = 4;
 429         s->len_chanlist = 4;
 430         s->maxdata = 0xffff;
 431         s->range_table = &range_a2150;
 432         s->do_cmd = a2150_ai_cmd;
 433         s->do_cmdtest = a2150_ai_cmdtest;
 434         s->insn_read = a2150_ai_rinsn;
 435         s->cancel = a2150_cancel;
 436
 437         /* need to do this for software counting of completed conversions, to
 438          * prevent hardware count from stopping acquisition */
 439         outw(HW_COUNT_DISABLE, dev->iobase + I8253_MODE_REG);
 440
 441         /*  set card's irq and dma levels */
 442         outw(devpriv->irq_dma_bits, dev->iobase + IRQ_DMA_CNTRL_REG);
 443
 444         /*  reset and sync adc clock circuitry */
 445         outw_p(DPD_BIT | APD_BIT, dev->iobase + CONFIG_REG);
 446         outw_p(DPD_BIT, dev->iobase + CONFIG_REG);
 447         /*  initialize configuration register */
 448         devpriv->config_bits = 0;
 449         outw(devpriv->config_bits, dev->iobase + CONFIG_REG);
 450         /*  wait until offset calibration is done, then enable analog inputs */
 451         for (i = 0; i < timeout; i++) {
 452                 if ((DCAL_BIT & inw(dev->iobase + STATUS_REG)) == 0)
 453                         break;
 454                 udelay(1000);
 455         }
 456         if (i == timeout) {
 457                 printk
 458                     (" timed out waiting for offset calibration to complete\n");
 459                 return -ETIME;
 460         }
 461         devpriv->config_bits |= ENABLE0_BIT | ENABLE1_BIT;
 462         outw(devpriv->config_bits, dev->iobase + CONFIG_REG);
 463
 464         return 0;
 465 };
 466
 467 static int a2150_detach(struct comedi_device *dev)
 468 {
 469         printk("comedi%d: %s: remove\n", dev->minor, driver_a2150.driver_name);
 470
 471         /* only free stuff if it has been allocated by _attach */
 472         if (dev->iobase) {
 473                 /*  put board in power-down mode */
 474                 outw(APD_BIT | DPD_BIT, dev->iobase + CONFIG_REG);
 475                 release_region(dev->iobase, A2150_SIZE);
 476         }
 477
 478         if (dev->irq)
 479                 free_irq(dev->irq, dev);
 480         if (devpriv) {
 481                 if (devpriv->dma)
 482                         free_dma(devpriv->dma);
 483                 kfree(devpriv->dma_buffer);
 484         }
 485
 486         return 0;
 487 };
 488
 489 static int a2150_cancel(struct comedi_device *dev, struct comedi_subdevice *s)
 490 {
 491         /*  disable dma on card */
 492         devpriv->irq_dma_bits &= ~DMA_INTR_EN_BIT & ~DMA_EN_BIT;
 493         outw(devpriv->irq_dma_bits, dev->iobase + IRQ_DMA_CNTRL_REG);
 494
 495         /*  disable computer's dma */
 496         disable_dma(devpriv->dma);
 497
 498         /*  clear fifo and reset triggering circuitry */
 499         outw(0, dev->iobase + FIFO_RESET_REG);
 500
 501         return 0;
 502 }
 503
 504 static int a2150_ai_cmdtest(struct comedi_device *dev,
 505                             struct comedi_subdevice *s, struct comedi_cmd *cmd)
 506 {
 507         int err = 0;
 508         int tmp;
 509         int startChan;
 510         int i;
 511
 512         /* step 1: make sure trigger sources are trivially valid */
 513
 514         tmp = cmd->start_src;
 515         cmd->start_src &= TRIG_NOW | TRIG_EXT;
 516         if (!cmd->start_src || tmp != cmd->start_src)
 517                 err++;
 518
 519         tmp = cmd->scan_begin_src;
 520         cmd->scan_begin_src &= TRIG_TIMER;
 521         if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
 522                 err++;
 523
 524         tmp = cmd->convert_src;
 525         cmd->convert_src &= TRIG_NOW;
 526         if (!cmd->convert_src || tmp != cmd->convert_src)
 527                 err++;
 528
 529         tmp = cmd->scan_end_src;
 530         cmd->scan_end_src &= TRIG_COUNT;
 531         if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
 532                 err++;
 533
 534         tmp = cmd->stop_src;
 535         cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
 536         if (!cmd->stop_src || tmp != cmd->stop_src)
 537                 err++;
 538
 539         if (err)
 540                 return 1;
 541
 542         /* step 2: make sure trigger sources are unique and mutually compatible */
 543
 544         if (cmd->start_src != TRIG_NOW && cmd->start_src != TRIG_EXT)
 545                 err++;
 546         if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
 547                 err++;
 548
 549         if (err)
 550                 return 2;
 551
 552         /* step 3: make sure arguments are trivially compatible */
 553
 554         if (cmd->start_arg != 0) {
 555                 cmd->start_arg = 0;
 556                 err++;
 557         }
 558         if (cmd->convert_src == TRIG_TIMER) {
 559                 if (cmd->convert_arg < thisboard->ai_speed) {
 560                         cmd->convert_arg = thisboard->ai_speed;
 561                         err++;
 562                 }
 563         }
 564         if (!cmd->chanlist_len) {
 565                 cmd->chanlist_len = 1;
 566                 err++;
 567         }
 568         if (cmd->scan_end_arg != cmd->chanlist_len) {
 569                 cmd->scan_end_arg = cmd->chanlist_len;
 570                 err++;
 571         }
 572         if (cmd->stop_src == TRIG_COUNT) {
 573                 if (!cmd->stop_arg) {
 574                         cmd->stop_arg = 1;
 575                         err++;
 576                 }
 577         } else {                /* TRIG_NONE */
 578                 if (cmd->stop_arg != 0) {
 579                         cmd->stop_arg = 0;
 580                         err++;
 581                 }
 582         }
 583
 584         if (err)
 585                 return 3;
 586
 587         /* step 4: fix up any arguments */
 588
 589         if (cmd->scan_begin_src == TRIG_TIMER) {
 590                 tmp = cmd->scan_begin_arg;
 591                 a2150_get_timing(dev, &cmd->scan_begin_arg, cmd->flags);
 592                 if (tmp != cmd->scan_begin_arg)
 593                         err++;
 594         }
 595
 596         if (err)
 597                 return 4;
 598
 599         /*  check channel/gain list against card's limitations */
 600         if (cmd->chanlist) {
 601                 startChan = CR_CHAN(cmd->chanlist[0]);
 602                 for (i = 1; i < cmd->chanlist_len; i++) {
 603                         if (CR_CHAN(cmd->chanlist[i]) != (startChan + i)) {
 604                                 comedi_error(dev,
 605                                              "entries in chanlist must be consecutive channels, counting upwards\n");
 606                                 err++;
 607                         }
 608                 }
 609                 if (cmd->chanlist_len == 2 && CR_CHAN(cmd->chanlist[0]) == 1) {
 610                         comedi_error(dev,
 611                                      "length 2 chanlist must be channels 0,1 or channels 2,3");
 612                         err++;
 613                 }
 614                 if (cmd->chanlist_len == 3) {
 615                         comedi_error(dev,
 616                                      "chanlist must have 1,2 or 4 channels");
 617                         err++;
 618                 }
 619                 if (CR_AREF(cmd->chanlist[0]) != CR_AREF(cmd->chanlist[1]) ||
 620                     CR_AREF(cmd->chanlist[2]) != CR_AREF(cmd->chanlist[3])) {
 621                         comedi_error(dev,
 622                                      "channels 0/1 and 2/3 must have the same analog reference");
 623                         err++;
 624                 }
 625         }
 626
 627         if (err)
 628                 return 5;
 629
 630         return 0;
 631 }
 632
 633 static int a2150_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 634 {
 635         struct comedi_async *async = s->async;
 636         struct comedi_cmd *cmd = &async->cmd;
 637         unsigned long lock_flags;
 638         unsigned int old_config_bits = devpriv->config_bits;
 639         unsigned int trigger_bits;
 640
 641         if (!dev->irq || !devpriv->dma) {
 642                 comedi_error(dev,
 643                              " irq and dma required, cannot do hardware conversions");
 644                 return -1;
 645         }
 646         if (cmd->flags & TRIG_RT) {
 647                 comedi_error(dev,
 648                              " dma incompatible with hard real-time interrupt (TRIG_RT), aborting");
 649                 return -1;
 650         }
 651         /*  clear fifo and reset triggering circuitry */
 652         outw(0, dev->iobase + FIFO_RESET_REG);
 653
 654         /* setup chanlist */
 655         if (a2150_set_chanlist(dev, CR_CHAN(cmd->chanlist[0]),
 656                                cmd->chanlist_len) < 0)
 657                 return -1;
 658
 659         /*  setup ac/dc coupling */
 660         if (CR_AREF(cmd->chanlist[0]) == AREF_OTHER)
 661                 devpriv->config_bits |= AC0_BIT;
 662         else
 663                 devpriv->config_bits &= ~AC0_BIT;
 664         if (CR_AREF(cmd->chanlist[2]) == AREF_OTHER)
 665                 devpriv->config_bits |= AC1_BIT;
 666         else
 667                 devpriv->config_bits &= ~AC1_BIT;
 668
 669         /*  setup timing */
 670         a2150_get_timing(dev, &cmd->scan_begin_arg, cmd->flags);
 671
 672         /*  send timing, channel, config bits */
 673         outw(devpriv->config_bits, dev->iobase + CONFIG_REG);
 674
 675         /*  initialize number of samples remaining */
 676         devpriv->count = cmd->stop_arg * cmd->chanlist_len;
 677
 678         /*  enable computer's dma */
 679         lock_flags = claim_dma_lock();
 680         disable_dma(devpriv->dma);
 681         /* clear flip-flop to make sure 2-byte registers for
 682          * count and address get set correctly */
 683         clear_dma_ff(devpriv->dma);
 684         set_dma_addr(devpriv->dma, virt_to_bus(devpriv->dma_buffer));
 685         /*  set size of transfer to fill in 1/3 second */
 686 #define ONE_THIRD_SECOND 333333333
 687         devpriv->dma_transfer_size =
 688             sizeof(devpriv->dma_buffer[0]) * cmd->chanlist_len *
 689             ONE_THIRD_SECOND / cmd->scan_begin_arg;
 690         if (devpriv->dma_transfer_size > A2150_DMA_BUFFER_SIZE)
 691                 devpriv->dma_transfer_size = A2150_DMA_BUFFER_SIZE;
 692         if (devpriv->dma_transfer_size < sizeof(devpriv->dma_buffer[0]))
 693                 devpriv->dma_transfer_size = sizeof(devpriv->dma_buffer[0]);
 694         devpriv->dma_transfer_size -=
 695             devpriv->dma_transfer_size % sizeof(devpriv->dma_buffer[0]);
 696         set_dma_count(devpriv->dma, devpriv->dma_transfer_size);
 697         enable_dma(devpriv->dma);
 698         release_dma_lock(lock_flags);
 699
 700         /* clear dma interrupt before enabling it, to try and get rid of that
 701          * one spurious interrupt that has been happening */
 702         outw(0x00, dev->iobase + DMA_TC_CLEAR_REG);
 703
 704         /*  enable dma on card */
 705         devpriv->irq_dma_bits |= DMA_INTR_EN_BIT | DMA_EN_BIT;
 706         outw(devpriv->irq_dma_bits, dev->iobase + IRQ_DMA_CNTRL_REG);
 707
 708         /*  may need to wait 72 sampling periods if timing was changed */
 709         i8254_load(dev->iobase + I8253_BASE_REG, 0, 2, 72, 0);
 710
 711         /*  setup start triggering */
 712         trigger_bits = 0;
 713         /*  decide if we need to wait 72 periods for valid data */
 714         if (cmd->start_src == TRIG_NOW &&
 715             (old_config_bits & CLOCK_MASK) !=
 716             (devpriv->config_bits & CLOCK_MASK)) {
 717                 /*  set trigger source to delay trigger */
 718                 trigger_bits |= DELAY_TRIGGER_BITS;
 719         } else {
 720                 /*  otherwise no delay */
 721                 trigger_bits |= POST_TRIGGER_BITS;
 722         }
 723         /*  enable external hardware trigger */
 724         if (cmd->start_src == TRIG_EXT) {
 725                 trigger_bits |= HW_TRIG_EN;
 726         } else if (cmd->start_src == TRIG_OTHER) {
 727                 /*  XXX add support for level/slope start trigger using TRIG_OTHER */
 728                 comedi_error(dev, "you shouldn't see this?");
 729         }
 730         /*  send trigger config bits */
 731         outw(trigger_bits, dev->iobase + TRIGGER_REG);
 732
 733         /*  start acquisition for soft trigger */
 734         if (cmd->start_src == TRIG_NOW) {
 735                 outw(0, dev->iobase + FIFO_START_REG);
 736         }
 737 #ifdef A2150_DEBUG
 738         ni_dump_regs(dev);
 739 #endif
 740
 741         return 0;
 742 }
 743
 744 static int a2150_ai_rinsn(struct comedi_device *dev, struct comedi_subdevice *s,
 745                           struct comedi_insn *insn, unsigned int *data)
 746 {
 747         unsigned int i, n;
 748         static const int timeout = 100000;
 749         static const int filter_delay = 36;
 750
 751         /*  clear fifo and reset triggering circuitry */
 752         outw(0, dev->iobase + FIFO_RESET_REG);
 753
 754         /* setup chanlist */
 755         if (a2150_set_chanlist(dev, CR_CHAN(insn->chanspec), 1) < 0)
 756                 return -1;
 757
 758         /*  set dc coupling */
 759         devpriv->config_bits &= ~AC0_BIT;
 760         devpriv->config_bits &= ~AC1_BIT;
 761
 762         /*  send timing, channel, config bits */
 763         outw(devpriv->config_bits, dev->iobase + CONFIG_REG);
 764
 765         /*  disable dma on card */
 766         devpriv->irq_dma_bits &= ~DMA_INTR_EN_BIT & ~DMA_EN_BIT;
 767         outw(devpriv->irq_dma_bits, dev->iobase + IRQ_DMA_CNTRL_REG);
 768
 769         /*  setup start triggering */
 770         outw(0, dev->iobase + TRIGGER_REG);
 771
 772         /*  start acquisition for soft trigger */
 773         outw(0, dev->iobase + FIFO_START_REG);
 774
 775         /* there is a 35.6 sample delay for data to get through the antialias filter */
 776         for (n = 0; n < filter_delay; n++) {
 777                 for (i = 0; i < timeout; i++) {
 778                         if (inw(dev->iobase + STATUS_REG) & FNE_BIT)
 779                                 break;
 780                         udelay(1);
 781                 }
 782                 if (i == timeout) {
 783                         comedi_error(dev, "timeout");
 784                         return -ETIME;
 785                 }
 786                 inw(dev->iobase + FIFO_DATA_REG);
 787         }
 788
 789         /*  read data */
 790         for (n = 0; n < insn->n; n++) {
 791                 for (i = 0; i < timeout; i++) {
 792                         if (inw(dev->iobase + STATUS_REG) & FNE_BIT)
 793                                 break;
 794                         udelay(1);
 795                 }
 796                 if (i == timeout) {
 797                         comedi_error(dev, "timeout");
 798                         return -ETIME;
 799                 }
 800 #ifdef A2150_DEBUG
 801                 ni_dump_regs(dev);
 802 #endif
 803                 data[n] = inw(dev->iobase + FIFO_DATA_REG);
 804 #ifdef A2150_DEBUG
 805                 printk(" data is %i\n", data[n]);
 806 #endif
 807                 data[n] ^= 0x8000;
 808         }
 809
 810         /*  clear fifo and reset triggering circuitry */
 811         outw(0, dev->iobase + FIFO_RESET_REG);
 812
 813         return n;
 814 }
 815
 816 /* sets bits in devpriv->clock_bits to nearest approximation of requested period,
 817  * adjusts requested period to actual timing. */
 818 static int a2150_get_timing(struct comedi_device *dev, unsigned int *period,
 819                             int flags)
 820 {
 821         int lub, glb, temp;
 822         int lub_divisor_shift, lub_index, glb_divisor_shift, glb_index;
 823         int i, j;
 824
 825         /*  initialize greatest lower and least upper bounds */
 826         lub_divisor_shift = 3;
 827         lub_index = 0;
 828         lub = thisboard->clock[lub_index] * (1 << lub_divisor_shift);
 829         glb_divisor_shift = 0;
 830         glb_index = thisboard->num_clocks - 1;
 831         glb = thisboard->clock[glb_index] * (1 << glb_divisor_shift);
 832
 833         /*  make sure period is in available range */
 834         if (*period < glb)
 835                 *period = glb;
 836         if (*period > lub)
 837                 *period = lub;
 838
 839         /*  we can multiply period by 1, 2, 4, or 8, using (1 << i) */
 840         for (i = 0; i < 4; i++) {
 841                 /*  there are a maximum of 4 master clocks */
 842                 for (j = 0; j < thisboard->num_clocks; j++) {
 843                         /*  temp is the period in nanosec we are evaluating */
 844                         temp = thisboard->clock[j] * (1 << i);
 845                         /*  if it is the best match yet */
 846                         if (temp < lub && temp >= *period) {
 847                                 lub_divisor_shift = i;
 848                                 lub_index = j;
 849                                 lub = temp;
 850                         }
 851                         if (temp > glb && temp <= *period) {
 852                                 glb_divisor_shift = i;
 853                                 glb_index = j;
 854                                 glb = temp;
 855                         }
 856                 }
 857         }
 858         flags &= TRIG_ROUND_MASK;
 859         switch (flags) {
 860         case TRIG_ROUND_NEAREST:
 861         default:
 862                 /*  if least upper bound is better approximation */
 863                 if (lub - *period < *period - glb) {
 864                         *period = lub;
 865                 } else {
 866                         *period = glb;
 867                 }
 868                 break;
 869         case TRIG_ROUND_UP:
 870                 *period = lub;
 871                 break;
 872         case TRIG_ROUND_DOWN:
 873                 *period = glb;
 874                 break;
 875         }
 876
 877         /*  set clock bits for config register appropriately */
 878         devpriv->config_bits &= ~CLOCK_MASK;
 879         if (*period == lub) {
 880                 devpriv->config_bits |=
 881                     CLOCK_SELECT_BITS(lub_index) |
 882                     CLOCK_DIVISOR_BITS(lub_divisor_shift);
 883         } else {
 884                 devpriv->config_bits |=
 885                     CLOCK_SELECT_BITS(glb_index) |
 886                     CLOCK_DIVISOR_BITS(glb_divisor_shift);
 887         }
 888
 889         return 0;
 890 }
 891
 892 static int a2150_set_chanlist(struct comedi_device *dev,
 893                               unsigned int start_channel,
 894                               unsigned int num_channels)
 895 {
 896         if (start_channel + num_channels > 4)
 897                 return -1;
 898
 899         devpriv->config_bits &= ~CHANNEL_MASK;
 900
 901         switch (num_channels) {
 902         case 1:
 903                 devpriv->config_bits |= CHANNEL_BITS(0x4 | start_channel);
 904                 break;
 905         case 2:
 906                 if (start_channel == 0) {
 907                         devpriv->config_bits |= CHANNEL_BITS(0x2);
 908                 } else if (start_channel == 2) {
 909                         devpriv->config_bits |= CHANNEL_BITS(0x3);
 910                 } else {
 911                         return -1;
 912                 }
 913                 break;
 914         case 4:
 915                 devpriv->config_bits |= CHANNEL_BITS(0x1);
 916                 break;
 917         default:
 918                 return -1;
 919                 break;
 920         }
 921
 922         return 0;
 923 }
 924
 925 MODULE_AUTHOR("Comedi http://www.comedi.org");
 926 MODULE_DESCRIPTION("Comedi low-level driver");
 927 MODULE_LICENSE("GPL");