1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * comedi/drivers/comedi_test.c 4 * 5 * Generates fake waveform signals that can be read through 6 * the command interface. It does _not_ read from any board; 7 * it just generates deterministic waveforms. 8 * Useful for various testing purposes. 9 * 10 * Copyright (C) 2002 Joachim Wuttke <[email protected]> 11 * Copyright (C) 2002 Frank Mori Hess <[email protected]> 12 * 13 * COMEDI - Linux Control and Measurement Device Interface 14 * Copyright (C) 2000 David A. Schleef <[email protected]> 15 */ 16 17 /* 18 * Driver: comedi_test 19 * Description: generates fake waveforms 20 * Author: Joachim Wuttke <[email protected]>, Frank Mori Hess 21 * <[email protected]>, ds 22 * Devices: 23 * Status: works 24 * Updated: Sat, 16 Mar 2002 17:34:48 -0800 25 * 26 * This driver is mainly for testing purposes, but can also be used to 27 * generate sample waveforms on systems that don't have data acquisition 28 * hardware. 29 * 30 * Auto-configuration is the default mode if no parameter is supplied during 31 * module loading. Manual configuration requires COMEDI userspace tool. 32 * To disable auto-configuration mode, pass "noauto=1" parameter for module 33 * loading. Refer modinfo or MODULE_PARM_DESC description below for details. 34 * 35 * Auto-configuration options: 36 * Refer modinfo or MODULE_PARM_DESC description below for details. 37 * 38 * Manual configuration options: 39 * [0] - Amplitude in microvolts for fake waveforms (default 1 volt) 40 * [1] - Period in microseconds for fake waveforms (default 0.1 sec) 41 * 42 * Generates a sawtooth wave on channel 0, square wave on channel 1, additional 43 * waveforms could be added to other channels (currently they return flatline 44 * zero volts). 45 */ 46 47 #include <linux/module.h> 48 #include <linux/comedi/comedidev.h> 49 #include <asm/div64.h> 50 #include <linux/timer.h> 51 #include <linux/ktime.h> 52 #include <linux/jiffies.h> 53 #include <linux/device.h> 54 #include <linux/kdev_t.h> 55 56 #define N_CHANS 8 57 #define DEV_NAME "comedi_testd" 58 #define CLASS_NAME "comedi_test" 59 60 static bool config_mode; 61 static unsigned int set_amplitude; 62 static unsigned int set_period; 63 static const struct class ctcls = { 64 .name = CLASS_NAME, 65 }; 66 static struct device *ctdev; 67 68 module_param_named(noauto, config_mode, bool, 0444); 69 MODULE_PARM_DESC(noauto, "Disable auto-configuration: (1=disable [defaults to enable])"); 70 71 module_param_named(amplitude, set_amplitude, uint, 0444); 72 MODULE_PARM_DESC(amplitude, "Set auto mode wave amplitude in microvolts: (defaults to 1 volt)"); 73 74 module_param_named(period, set_period, uint, 0444); 75 MODULE_PARM_DESC(period, "Set auto mode wave period in microseconds: (defaults to 0.1 sec)"); 76 77 /* Data unique to this driver */ 78 struct waveform_private { 79 struct timer_list ai_timer; /* timer for AI commands */ 80 u64 ai_convert_time; /* time of next AI conversion in usec */ 81 unsigned int wf_amplitude; /* waveform amplitude in microvolts */ 82 unsigned int wf_period; /* waveform period in microseconds */ 83 unsigned int wf_current; /* current time in waveform period */ 84 unsigned int ai_scan_period; /* AI scan period in usec */ 85 unsigned int ai_convert_period; /* AI conversion period in usec */ 86 struct timer_list ao_timer; /* timer for AO commands */ 87 struct comedi_device *dev; /* parent comedi device */ 88 u64 ao_last_scan_time; /* time of previous AO scan in usec */ 89 unsigned int ao_scan_period; /* AO scan period in usec */ 90 unsigned short ao_loopbacks[N_CHANS]; 91 }; 92 93 /* fake analog input ranges */ 94 static const struct comedi_lrange waveform_ai_ranges = { 95 2, { 96 BIP_RANGE(10), 97 BIP_RANGE(5) 98 } 99 }; 100 101 static unsigned short fake_sawtooth(struct comedi_device *dev, 102 unsigned int range_index, 103 unsigned int current_time) 104 { 105 struct waveform_private *devpriv = dev->private; 106 struct comedi_subdevice *s = dev->read_subdev; 107 unsigned int offset = s->maxdata / 2; 108 u64 value; 109 const struct comedi_krange *krange = 110 &s->range_table->range[range_index]; 111 u64 binary_amplitude; 112 113 binary_amplitude = s->maxdata; 114 binary_amplitude *= devpriv->wf_amplitude; 115 do_div(binary_amplitude, krange->max - krange->min); 116 117 value = current_time; 118 value *= binary_amplitude * 2; 119 do_div(value, devpriv->wf_period); 120 value += offset; 121 /* get rid of sawtooth's dc offset and clamp value */ 122 if (value < binary_amplitude) { 123 value = 0; /* negative saturation */ 124 } else { 125 value -= binary_amplitude; 126 if (value > s->maxdata) 127 value = s->maxdata; /* positive saturation */ 128 } 129 130 return value; 131 } 132 133 static unsigned short fake_squarewave(struct comedi_device *dev, 134 unsigned int range_index, 135 unsigned int current_time) 136 { 137 struct waveform_private *devpriv = dev->private; 138 struct comedi_subdevice *s = dev->read_subdev; 139 unsigned int offset = s->maxdata / 2; 140 u64 value; 141 const struct comedi_krange *krange = 142 &s->range_table->range[range_index]; 143 144 value = s->maxdata; 145 value *= devpriv->wf_amplitude; 146 do_div(value, krange->max - krange->min); 147 148 /* get one of two values for square-wave and clamp */ 149 if (current_time < devpriv->wf_period / 2) { 150 if (offset < value) 151 value = 0; /* negative saturation */ 152 else 153 value = offset - value; 154 } else { 155 value += offset; 156 if (value > s->maxdata) 157 value = s->maxdata; /* positive saturation */ 158 } 159 160 return value; 161 } 162 163 static unsigned short fake_flatline(struct comedi_device *dev, 164 unsigned int range_index, 165 unsigned int current_time) 166 { 167 return dev->read_subdev->maxdata / 2; 168 } 169 170 /* generates a different waveform depending on what channel is read */ 171 static unsigned short fake_waveform(struct comedi_device *dev, 172 unsigned int channel, unsigned int range, 173 unsigned int current_time) 174 { 175 enum { 176 SAWTOOTH_CHAN, 177 SQUARE_CHAN, 178 }; 179 switch (channel) { 180 case SAWTOOTH_CHAN: 181 return fake_sawtooth(dev, range, current_time); 182 case SQUARE_CHAN: 183 return fake_squarewave(dev, range, current_time); 184 default: 185 break; 186 } 187 188 return fake_flatline(dev, range, current_time); 189 } 190 191 /* 192 * This is the background routine used to generate arbitrary data. 193 * It should run in the background; therefore it is scheduled by 194 * a timer mechanism. 195 */ 196 static void waveform_ai_timer(struct timer_list *t) 197 { 198 struct waveform_private *devpriv = from_timer(devpriv, t, ai_timer); 199 struct comedi_device *dev = devpriv->dev; 200 struct comedi_subdevice *s = dev->read_subdev; 201 struct comedi_async *async = s->async; 202 struct comedi_cmd *cmd = &async->cmd; 203 u64 now; 204 unsigned int nsamples; 205 unsigned int time_increment; 206 207 now = ktime_to_us(ktime_get()); 208 nsamples = comedi_nsamples_left(s, UINT_MAX); 209 210 while (nsamples && devpriv->ai_convert_time < now) { 211 unsigned int chanspec = cmd->chanlist[async->cur_chan]; 212 unsigned short sample; 213 214 sample = fake_waveform(dev, CR_CHAN(chanspec), 215 CR_RANGE(chanspec), devpriv->wf_current); 216 if (comedi_buf_write_samples(s, &sample, 1) == 0) 217 goto overrun; 218 time_increment = devpriv->ai_convert_period; 219 if (async->scan_progress == 0) { 220 /* done last conversion in scan, so add dead time */ 221 time_increment += devpriv->ai_scan_period - 222 devpriv->ai_convert_period * 223 cmd->scan_end_arg; 224 } 225 devpriv->wf_current += time_increment; 226 if (devpriv->wf_current >= devpriv->wf_period) 227 devpriv->wf_current %= devpriv->wf_period; 228 devpriv->ai_convert_time += time_increment; 229 nsamples--; 230 } 231 232 if (cmd->stop_src == TRIG_COUNT && async->scans_done >= cmd->stop_arg) { 233 async->events |= COMEDI_CB_EOA; 234 } else { 235 if (devpriv->ai_convert_time > now) 236 time_increment = devpriv->ai_convert_time - now; 237 else 238 time_increment = 1; 239 mod_timer(&devpriv->ai_timer, 240 jiffies + usecs_to_jiffies(time_increment)); 241 } 242 243 overrun: 244 comedi_handle_events(dev, s); 245 } 246 247 static int waveform_ai_cmdtest(struct comedi_device *dev, 248 struct comedi_subdevice *s, 249 struct comedi_cmd *cmd) 250 { 251 int err = 0; 252 unsigned int arg, limit; 253 254 /* Step 1 : check if triggers are trivially valid */ 255 256 err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW); 257 err |= comedi_check_trigger_src(&cmd->scan_begin_src, 258 TRIG_FOLLOW | TRIG_TIMER); 259 err |= comedi_check_trigger_src(&cmd->convert_src, 260 TRIG_NOW | TRIG_TIMER); 261 err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT); 262 err |= comedi_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE); 263 264 if (err) 265 return 1; 266 267 /* Step 2a : make sure trigger sources are unique */ 268 269 err |= comedi_check_trigger_is_unique(cmd->convert_src); 270 err |= comedi_check_trigger_is_unique(cmd->stop_src); 271 272 /* Step 2b : and mutually compatible */ 273 274 if (cmd->scan_begin_src == TRIG_FOLLOW && cmd->convert_src == TRIG_NOW) 275 err |= -EINVAL; /* scan period would be 0 */ 276 277 if (err) 278 return 2; 279 280 /* Step 3: check if arguments are trivially valid */ 281 282 err |= comedi_check_trigger_arg_is(&cmd->start_arg, 0); 283 284 if (cmd->convert_src == TRIG_NOW) { 285 err |= comedi_check_trigger_arg_is(&cmd->convert_arg, 0); 286 } else { /* cmd->convert_src == TRIG_TIMER */ 287 if (cmd->scan_begin_src == TRIG_FOLLOW) { 288 err |= comedi_check_trigger_arg_min(&cmd->convert_arg, 289 NSEC_PER_USEC); 290 } 291 } 292 293 if (cmd->scan_begin_src == TRIG_FOLLOW) { 294 err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, 0); 295 } else { /* cmd->scan_begin_src == TRIG_TIMER */ 296 err |= comedi_check_trigger_arg_min(&cmd->scan_begin_arg, 297 NSEC_PER_USEC); 298 } 299 300 err |= comedi_check_trigger_arg_min(&cmd->chanlist_len, 1); 301 err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg, 302 cmd->chanlist_len); 303 304 if (cmd->stop_src == TRIG_COUNT) 305 err |= comedi_check_trigger_arg_min(&cmd->stop_arg, 1); 306 else /* cmd->stop_src == TRIG_NONE */ 307 err |= comedi_check_trigger_arg_is(&cmd->stop_arg, 0); 308 309 if (err) 310 return 3; 311 312 /* step 4: fix up any arguments */ 313 314 if (cmd->convert_src == TRIG_TIMER) { 315 /* round convert_arg to nearest microsecond */ 316 arg = cmd->convert_arg; 317 arg = min(arg, 318 rounddown(UINT_MAX, (unsigned int)NSEC_PER_USEC)); 319 arg = NSEC_PER_USEC * DIV_ROUND_CLOSEST(arg, NSEC_PER_USEC); 320 if (cmd->scan_begin_arg == TRIG_TIMER) { 321 /* limit convert_arg to keep scan_begin_arg in range */ 322 limit = UINT_MAX / cmd->scan_end_arg; 323 limit = rounddown(limit, (unsigned int)NSEC_PER_SEC); 324 arg = min(arg, limit); 325 } 326 err |= comedi_check_trigger_arg_is(&cmd->convert_arg, arg); 327 } 328 329 if (cmd->scan_begin_src == TRIG_TIMER) { 330 /* round scan_begin_arg to nearest microsecond */ 331 arg = cmd->scan_begin_arg; 332 arg = min(arg, 333 rounddown(UINT_MAX, (unsigned int)NSEC_PER_USEC)); 334 arg = NSEC_PER_USEC * DIV_ROUND_CLOSEST(arg, NSEC_PER_USEC); 335 if (cmd->convert_src == TRIG_TIMER) { 336 /* but ensure scan_begin_arg is large enough */ 337 arg = max(arg, cmd->convert_arg * cmd->scan_end_arg); 338 } 339 err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, arg); 340 } 341 342 if (err) 343 return 4; 344 345 return 0; 346 } 347 348 static int waveform_ai_cmd(struct comedi_device *dev, 349 struct comedi_subdevice *s) 350 { 351 struct waveform_private *devpriv = dev->private; 352 struct comedi_cmd *cmd = &s->async->cmd; 353 unsigned int first_convert_time; 354 u64 wf_current; 355 356 if (cmd->flags & CMDF_PRIORITY) { 357 dev_err(dev->class_dev, 358 "commands at RT priority not supported in this driver\n"); 359 return -1; 360 } 361 362 if (cmd->convert_src == TRIG_NOW) 363 devpriv->ai_convert_period = 0; 364 else /* cmd->convert_src == TRIG_TIMER */ 365 devpriv->ai_convert_period = cmd->convert_arg / NSEC_PER_USEC; 366 367 if (cmd->scan_begin_src == TRIG_FOLLOW) { 368 devpriv->ai_scan_period = devpriv->ai_convert_period * 369 cmd->scan_end_arg; 370 } else { /* cmd->scan_begin_src == TRIG_TIMER */ 371 devpriv->ai_scan_period = cmd->scan_begin_arg / NSEC_PER_USEC; 372 } 373 374 /* 375 * Simulate first conversion to occur at convert period after 376 * conversion timer starts. If scan_begin_src is TRIG_FOLLOW, assume 377 * the conversion timer starts immediately. If scan_begin_src is 378 * TRIG_TIMER, assume the conversion timer starts after the scan 379 * period. 380 */ 381 first_convert_time = devpriv->ai_convert_period; 382 if (cmd->scan_begin_src == TRIG_TIMER) 383 first_convert_time += devpriv->ai_scan_period; 384 devpriv->ai_convert_time = ktime_to_us(ktime_get()) + 385 first_convert_time; 386 387 /* Determine time within waveform period at time of conversion. */ 388 wf_current = devpriv->ai_convert_time; 389 devpriv->wf_current = do_div(wf_current, devpriv->wf_period); 390 391 /* 392 * Schedule timer to expire just after first conversion time. 393 * Seem to need an extra jiffy here, otherwise timer expires slightly 394 * early! 395 */ 396 devpriv->ai_timer.expires = 397 jiffies + usecs_to_jiffies(devpriv->ai_convert_period) + 1; 398 add_timer(&devpriv->ai_timer); 399 return 0; 400 } 401 402 static int waveform_ai_cancel(struct comedi_device *dev, 403 struct comedi_subdevice *s) 404 { 405 struct waveform_private *devpriv = dev->private; 406 407 if (in_softirq()) { 408 /* Assume we were called from the timer routine itself. */ 409 del_timer(&devpriv->ai_timer); 410 } else { 411 del_timer_sync(&devpriv->ai_timer); 412 } 413 return 0; 414 } 415 416 static int waveform_ai_insn_read(struct comedi_device *dev, 417 struct comedi_subdevice *s, 418 struct comedi_insn *insn, unsigned int *data) 419 { 420 struct waveform_private *devpriv = dev->private; 421 int i, chan = CR_CHAN(insn->chanspec); 422 423 for (i = 0; i < insn->n; i++) 424 data[i] = devpriv->ao_loopbacks[chan]; 425 426 return insn->n; 427 } 428 429 /* 430 * This is the background routine to handle AO commands, scheduled by 431 * a timer mechanism. 432 */ 433 static void waveform_ao_timer(struct timer_list *t) 434 { 435 struct waveform_private *devpriv = from_timer(devpriv, t, ao_timer); 436 struct comedi_device *dev = devpriv->dev; 437 struct comedi_subdevice *s = dev->write_subdev; 438 struct comedi_async *async = s->async; 439 struct comedi_cmd *cmd = &async->cmd; 440 u64 now; 441 u64 scans_since; 442 unsigned int scans_avail = 0; 443 444 /* determine number of scan periods since last time */ 445 now = ktime_to_us(ktime_get()); 446 scans_since = now - devpriv->ao_last_scan_time; 447 do_div(scans_since, devpriv->ao_scan_period); 448 if (scans_since) { 449 unsigned int i; 450 451 /* determine scans in buffer, limit to scans to do this time */ 452 scans_avail = comedi_nscans_left(s, 0); 453 if (scans_avail > scans_since) 454 scans_avail = scans_since; 455 if (scans_avail) { 456 /* skip all but the last scan to save processing time */ 457 if (scans_avail > 1) { 458 unsigned int skip_bytes, nbytes; 459 460 skip_bytes = 461 comedi_samples_to_bytes(s, cmd->scan_end_arg * 462 (scans_avail - 1)); 463 nbytes = comedi_buf_read_alloc(s, skip_bytes); 464 comedi_buf_read_free(s, nbytes); 465 comedi_inc_scan_progress(s, nbytes); 466 if (nbytes < skip_bytes) { 467 /* unexpected underrun! (cancelled?) */ 468 async->events |= COMEDI_CB_OVERFLOW; 469 goto underrun; 470 } 471 } 472 /* output the last scan */ 473 for (i = 0; i < cmd->scan_end_arg; i++) { 474 unsigned int chan = CR_CHAN(cmd->chanlist[i]); 475 unsigned short *pd; 476 477 pd = &devpriv->ao_loopbacks[chan]; 478 479 if (!comedi_buf_read_samples(s, pd, 1)) { 480 /* unexpected underrun! (cancelled?) */ 481 async->events |= COMEDI_CB_OVERFLOW; 482 goto underrun; 483 } 484 } 485 /* advance time of last scan */ 486 devpriv->ao_last_scan_time += 487 (u64)scans_avail * devpriv->ao_scan_period; 488 } 489 } 490 if (cmd->stop_src == TRIG_COUNT && async->scans_done >= cmd->stop_arg) { 491 async->events |= COMEDI_CB_EOA; 492 } else if (scans_avail < scans_since) { 493 async->events |= COMEDI_CB_OVERFLOW; 494 } else { 495 unsigned int time_inc = devpriv->ao_last_scan_time + 496 devpriv->ao_scan_period - now; 497 498 mod_timer(&devpriv->ao_timer, 499 jiffies + usecs_to_jiffies(time_inc)); 500 } 501 502 underrun: 503 comedi_handle_events(dev, s); 504 } 505 506 static int waveform_ao_inttrig_start(struct comedi_device *dev, 507 struct comedi_subdevice *s, 508 unsigned int trig_num) 509 { 510 struct waveform_private *devpriv = dev->private; 511 struct comedi_async *async = s->async; 512 struct comedi_cmd *cmd = &async->cmd; 513 514 if (trig_num != cmd->start_arg) 515 return -EINVAL; 516 517 async->inttrig = NULL; 518 519 devpriv->ao_last_scan_time = ktime_to_us(ktime_get()); 520 devpriv->ao_timer.expires = 521 jiffies + usecs_to_jiffies(devpriv->ao_scan_period); 522 add_timer(&devpriv->ao_timer); 523 524 return 1; 525 } 526 527 static int waveform_ao_cmdtest(struct comedi_device *dev, 528 struct comedi_subdevice *s, 529 struct comedi_cmd *cmd) 530 { 531 int err = 0; 532 unsigned int arg; 533 534 /* Step 1 : check if triggers are trivially valid */ 535 536 err |= comedi_check_trigger_src(&cmd->start_src, TRIG_INT); 537 err |= comedi_check_trigger_src(&cmd->scan_begin_src, TRIG_TIMER); 538 err |= comedi_check_trigger_src(&cmd->convert_src, TRIG_NOW); 539 err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT); 540 err |= comedi_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE); 541 542 if (err) 543 return 1; 544 545 /* Step 2a : make sure trigger sources are unique */ 546 547 err |= comedi_check_trigger_is_unique(cmd->stop_src); 548 549 /* Step 2b : and mutually compatible */ 550 551 if (err) 552 return 2; 553 554 /* Step 3: check if arguments are trivially valid */ 555 556 err |= comedi_check_trigger_arg_min(&cmd->scan_begin_arg, 557 NSEC_PER_USEC); 558 err |= comedi_check_trigger_arg_is(&cmd->convert_arg, 0); 559 err |= comedi_check_trigger_arg_min(&cmd->chanlist_len, 1); 560 err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg, 561 cmd->chanlist_len); 562 if (cmd->stop_src == TRIG_COUNT) 563 err |= comedi_check_trigger_arg_min(&cmd->stop_arg, 1); 564 else /* cmd->stop_src == TRIG_NONE */ 565 err |= comedi_check_trigger_arg_is(&cmd->stop_arg, 0); 566 567 if (err) 568 return 3; 569 570 /* step 4: fix up any arguments */ 571 572 /* round scan_begin_arg to nearest microsecond */ 573 arg = cmd->scan_begin_arg; 574 arg = min(arg, rounddown(UINT_MAX, (unsigned int)NSEC_PER_USEC)); 575 arg = NSEC_PER_USEC * DIV_ROUND_CLOSEST(arg, NSEC_PER_USEC); 576 err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, arg); 577 578 if (err) 579 return 4; 580 581 return 0; 582 } 583 584 static int waveform_ao_cmd(struct comedi_device *dev, 585 struct comedi_subdevice *s) 586 { 587 struct waveform_private *devpriv = dev->private; 588 struct comedi_cmd *cmd = &s->async->cmd; 589 590 if (cmd->flags & CMDF_PRIORITY) { 591 dev_err(dev->class_dev, 592 "commands at RT priority not supported in this driver\n"); 593 return -1; 594 } 595 596 devpriv->ao_scan_period = cmd->scan_begin_arg / NSEC_PER_USEC; 597 s->async->inttrig = waveform_ao_inttrig_start; 598 return 0; 599 } 600 601 static int waveform_ao_cancel(struct comedi_device *dev, 602 struct comedi_subdevice *s) 603 { 604 struct waveform_private *devpriv = dev->private; 605 606 s->async->inttrig = NULL; 607 if (in_softirq()) { 608 /* Assume we were called from the timer routine itself. */ 609 del_timer(&devpriv->ao_timer); 610 } else { 611 del_timer_sync(&devpriv->ao_timer); 612 } 613 return 0; 614 } 615 616 static int waveform_ao_insn_write(struct comedi_device *dev, 617 struct comedi_subdevice *s, 618 struct comedi_insn *insn, unsigned int *data) 619 { 620 struct waveform_private *devpriv = dev->private; 621 int i, chan = CR_CHAN(insn->chanspec); 622 623 for (i = 0; i < insn->n; i++) 624 devpriv->ao_loopbacks[chan] = data[i]; 625 626 return insn->n; 627 } 628 629 static int waveform_ai_insn_config(struct comedi_device *dev, 630 struct comedi_subdevice *s, 631 struct comedi_insn *insn, 632 unsigned int *data) 633 { 634 if (data[0] == INSN_CONFIG_GET_CMD_TIMING_CONSTRAINTS) { 635 /* 636 * input: data[1], data[2] : scan_begin_src, convert_src 637 * output: data[1], data[2] : scan_begin_min, convert_min 638 */ 639 if (data[1] == TRIG_FOLLOW) { 640 /* exactly TRIG_FOLLOW case */ 641 data[1] = 0; 642 data[2] = NSEC_PER_USEC; 643 } else { 644 data[1] = NSEC_PER_USEC; 645 if (data[2] & TRIG_TIMER) 646 data[2] = NSEC_PER_USEC; 647 else 648 data[2] = 0; 649 } 650 return 0; 651 } 652 653 return -EINVAL; 654 } 655 656 static int waveform_ao_insn_config(struct comedi_device *dev, 657 struct comedi_subdevice *s, 658 struct comedi_insn *insn, 659 unsigned int *data) 660 { 661 if (data[0] == INSN_CONFIG_GET_CMD_TIMING_CONSTRAINTS) { 662 /* we don't care about actual channels */ 663 data[1] = NSEC_PER_USEC; /* scan_begin_min */ 664 data[2] = 0; /* convert_min */ 665 return 0; 666 } 667 668 return -EINVAL; 669 } 670 671 static int waveform_common_attach(struct comedi_device *dev, 672 int amplitude, int period) 673 { 674 struct waveform_private *devpriv; 675 struct comedi_subdevice *s; 676 int i; 677 int ret; 678 679 devpriv = comedi_alloc_devpriv(dev, sizeof(*devpriv)); 680 if (!devpriv) 681 return -ENOMEM; 682 683 devpriv->wf_amplitude = amplitude; 684 devpriv->wf_period = period; 685 686 ret = comedi_alloc_subdevices(dev, 2); 687 if (ret) 688 return ret; 689 690 s = &dev->subdevices[0]; 691 dev->read_subdev = s; 692 /* analog input subdevice */ 693 s->type = COMEDI_SUBD_AI; 694 s->subdev_flags = SDF_READABLE | SDF_GROUND | SDF_CMD_READ; 695 s->n_chan = N_CHANS; 696 s->maxdata = 0xffff; 697 s->range_table = &waveform_ai_ranges; 698 s->len_chanlist = s->n_chan * 2; 699 s->insn_read = waveform_ai_insn_read; 700 s->do_cmd = waveform_ai_cmd; 701 s->do_cmdtest = waveform_ai_cmdtest; 702 s->cancel = waveform_ai_cancel; 703 s->insn_config = waveform_ai_insn_config; 704 705 s = &dev->subdevices[1]; 706 dev->write_subdev = s; 707 /* analog output subdevice (loopback) */ 708 s->type = COMEDI_SUBD_AO; 709 s->subdev_flags = SDF_WRITABLE | SDF_GROUND | SDF_CMD_WRITE; 710 s->n_chan = N_CHANS; 711 s->maxdata = 0xffff; 712 s->range_table = &waveform_ai_ranges; 713 s->len_chanlist = s->n_chan; 714 s->insn_write = waveform_ao_insn_write; 715 s->insn_read = waveform_ai_insn_read; /* do same as AI insn_read */ 716 s->do_cmd = waveform_ao_cmd; 717 s->do_cmdtest = waveform_ao_cmdtest; 718 s->cancel = waveform_ao_cancel; 719 s->insn_config = waveform_ao_insn_config; 720 721 /* Our default loopback value is just a 0V flatline */ 722 for (i = 0; i < s->n_chan; i++) 723 devpriv->ao_loopbacks[i] = s->maxdata / 2; 724 725 devpriv->dev = dev; 726 timer_setup(&devpriv->ai_timer, waveform_ai_timer, 0); 727 timer_setup(&devpriv->ao_timer, waveform_ao_timer, 0); 728 729 dev_info(dev->class_dev, 730 "%s: %u microvolt, %u microsecond waveform attached\n", 731 dev->board_name, 732 devpriv->wf_amplitude, devpriv->wf_period); 733 734 return 0; 735 } 736 737 static int waveform_attach(struct comedi_device *dev, 738 struct comedi_devconfig *it) 739 { 740 int amplitude = it->options[0]; 741 int period = it->options[1]; 742 743 /* set default amplitude and period */ 744 if (amplitude <= 0) 745 amplitude = 1000000; /* 1 volt */ 746 if (period <= 0) 747 period = 100000; /* 0.1 sec */ 748 749 return waveform_common_attach(dev, amplitude, period); 750 } 751 752 static int waveform_auto_attach(struct comedi_device *dev, 753 unsigned long context_unused) 754 { 755 int amplitude = set_amplitude; 756 int period = set_period; 757 758 /* set default amplitude and period */ 759 if (!amplitude) 760 amplitude = 1000000; /* 1 volt */ 761 if (!period) 762 period = 100000; /* 0.1 sec */ 763 764 return waveform_common_attach(dev, amplitude, period); 765 } 766 767 static void waveform_detach(struct comedi_device *dev) 768 { 769 struct waveform_private *devpriv = dev->private; 770 771 if (devpriv) { 772 del_timer_sync(&devpriv->ai_timer); 773 del_timer_sync(&devpriv->ao_timer); 774 } 775 } 776 777 static struct comedi_driver waveform_driver = { 778 .driver_name = "comedi_test", 779 .module = THIS_MODULE, 780 .attach = waveform_attach, 781 .auto_attach = waveform_auto_attach, 782 .detach = waveform_detach, 783 }; 784 785 /* 786 * For auto-configuration, a device is created to stand in for a 787 * real hardware device. 788 */ 789 static int __init comedi_test_init(void) 790 { 791 int ret; 792 793 ret = comedi_driver_register(&waveform_driver); 794 if (ret) { 795 pr_err("comedi_test: unable to register driver\n"); 796 return ret; 797 } 798 799 if (!config_mode) { 800 ret = class_register(&ctcls); 801 if (ret) { 802 pr_warn("comedi_test: unable to create class\n"); 803 goto clean3; 804 } 805 806 ctdev = device_create(&ctcls, NULL, MKDEV(0, 0), NULL, DEV_NAME); 807 if (IS_ERR(ctdev)) { 808 pr_warn("comedi_test: unable to create device\n"); 809 goto clean2; 810 } 811 812 ret = comedi_auto_config(ctdev, &waveform_driver, 0); 813 if (ret) { 814 pr_warn("comedi_test: unable to auto-configure device\n"); 815 goto clean; 816 } 817 } 818 819 return 0; 820 821 clean: 822 device_destroy(&ctcls, MKDEV(0, 0)); 823 clean2: 824 class_unregister(&ctcls); 825 clean3: 826 return 0; 827 } 828 module_init(comedi_test_init); 829 830 static void __exit comedi_test_exit(void) 831 { 832 if (ctdev) 833 comedi_auto_unconfig(ctdev); 834 835 if (class_is_registered(&ctcls)) { 836 device_destroy(&ctcls, MKDEV(0, 0)); 837 class_unregister(&ctcls); 838 } 839 840 comedi_driver_unregister(&waveform_driver); 841 } 842 module_exit(comedi_test_exit); 843 844 MODULE_AUTHOR("Comedi https://www.comedi.org"); 845 MODULE_DESCRIPTION("Comedi low-level driver"); 846 MODULE_LICENSE("GPL"); 847