| 1 | /* |
| 2 | * comedi/drivers/comedi_test.c |
| 3 | * |
| 4 | * Generates fake waveform signals that can be read through |
| 5 | * the command interface. It does _not_ read from any board; |
| 6 | * it just generates deterministic waveforms. |
| 7 | * Useful for various testing purposes. |
| 8 | * |
| 9 | * Copyright (C) 2002 Joachim Wuttke <Joachim.Wuttke@icn.siemens.de> |
| 10 | * Copyright (C) 2002 Frank Mori Hess <fmhess@users.sourceforge.net> |
| 11 | * |
| 12 | * COMEDI - Linux Control and Measurement Device Interface |
| 13 | * Copyright (C) 2000 David A. Schleef <ds@schleef.org> |
| 14 | * |
| 15 | * This program is free software; you can redistribute it and/or modify |
| 16 | * it under the terms of the GNU General Public License as published by |
| 17 | * the Free Software Foundation; either version 2 of the License, or |
| 18 | * (at your option) any later version. |
| 19 | * |
| 20 | * This program is distributed in the hope that it will be useful, |
| 21 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 22 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 23 | * GNU General Public License for more details. |
| 24 | */ |
| 25 | |
| 26 | /* |
| 27 | * Driver: comedi_test |
| 28 | * Description: generates fake waveforms |
| 29 | * Author: Joachim Wuttke <Joachim.Wuttke@icn.siemens.de>, Frank Mori Hess |
| 30 | * <fmhess@users.sourceforge.net>, ds |
| 31 | * Devices: |
| 32 | * Status: works |
| 33 | * Updated: Sat, 16 Mar 2002 17:34:48 -0800 |
| 34 | * |
| 35 | * This driver is mainly for testing purposes, but can also be used to |
| 36 | * generate sample waveforms on systems that don't have data acquisition |
| 37 | * hardware. |
| 38 | * |
| 39 | * Configuration options: |
| 40 | * [0] - Amplitude in microvolts for fake waveforms (default 1 volt) |
| 41 | * [1] - Period in microseconds for fake waveforms (default 0.1 sec) |
| 42 | * |
| 43 | * Generates a sawtooth wave on channel 0, square wave on channel 1, additional |
| 44 | * waveforms could be added to other channels (currently they return flatline |
| 45 | * zero volts). |
| 46 | */ |
| 47 | |
| 48 | #include <linux/module.h> |
| 49 | #include "../comedidev.h" |
| 50 | |
| 51 | #include <asm/div64.h> |
| 52 | |
| 53 | #include <linux/timer.h> |
| 54 | #include <linux/ktime.h> |
| 55 | |
| 56 | #define N_CHANS 8 |
| 57 | |
| 58 | enum waveform_state_bits { |
| 59 | WAVEFORM_AI_RUNNING = 0 |
| 60 | }; |
| 61 | |
| 62 | /* Data unique to this driver */ |
| 63 | struct waveform_private { |
| 64 | struct timer_list ai_timer; /* timer for AI commands */ |
| 65 | u64 ai_last_scan_time; /* time of last AI scan in usec */ |
| 66 | unsigned int wf_amplitude; /* waveform amplitude in microvolts */ |
| 67 | unsigned int wf_period; /* waveform period in microseconds */ |
| 68 | unsigned int wf_current; /* current time in waveform period */ |
| 69 | unsigned long state_bits; |
| 70 | unsigned int ai_scan_period; /* AI scan period in usec */ |
| 71 | unsigned int ai_convert_period; /* AI conversion period in usec */ |
| 72 | unsigned int ao_loopbacks[N_CHANS]; |
| 73 | }; |
| 74 | |
| 75 | /* fake analog input ranges */ |
| 76 | static const struct comedi_lrange waveform_ai_ranges = { |
| 77 | 2, { |
| 78 | BIP_RANGE(10), |
| 79 | BIP_RANGE(5) |
| 80 | } |
| 81 | }; |
| 82 | |
| 83 | static unsigned short fake_sawtooth(struct comedi_device *dev, |
| 84 | unsigned int range_index, |
| 85 | unsigned int current_time) |
| 86 | { |
| 87 | struct waveform_private *devpriv = dev->private; |
| 88 | struct comedi_subdevice *s = dev->read_subdev; |
| 89 | unsigned int offset = s->maxdata / 2; |
| 90 | u64 value; |
| 91 | const struct comedi_krange *krange = |
| 92 | &s->range_table->range[range_index]; |
| 93 | u64 binary_amplitude; |
| 94 | |
| 95 | binary_amplitude = s->maxdata; |
| 96 | binary_amplitude *= devpriv->wf_amplitude; |
| 97 | do_div(binary_amplitude, krange->max - krange->min); |
| 98 | |
| 99 | value = current_time; |
| 100 | value *= binary_amplitude * 2; |
| 101 | do_div(value, devpriv->wf_period); |
| 102 | value += offset; |
| 103 | /* get rid of sawtooth's dc offset and clamp value */ |
| 104 | if (value < binary_amplitude) { |
| 105 | value = 0; /* negative saturation */ |
| 106 | } else { |
| 107 | value -= binary_amplitude; |
| 108 | if (value > s->maxdata) |
| 109 | value = s->maxdata; /* positive saturation */ |
| 110 | } |
| 111 | |
| 112 | return value; |
| 113 | } |
| 114 | |
| 115 | static unsigned short fake_squarewave(struct comedi_device *dev, |
| 116 | unsigned int range_index, |
| 117 | unsigned int current_time) |
| 118 | { |
| 119 | struct waveform_private *devpriv = dev->private; |
| 120 | struct comedi_subdevice *s = dev->read_subdev; |
| 121 | unsigned int offset = s->maxdata / 2; |
| 122 | u64 value; |
| 123 | const struct comedi_krange *krange = |
| 124 | &s->range_table->range[range_index]; |
| 125 | |
| 126 | value = s->maxdata; |
| 127 | value *= devpriv->wf_amplitude; |
| 128 | do_div(value, krange->max - krange->min); |
| 129 | |
| 130 | /* get one of two values for square-wave and clamp */ |
| 131 | if (current_time < devpriv->wf_period / 2) { |
| 132 | if (offset < value) |
| 133 | value = 0; /* negative saturation */ |
| 134 | else |
| 135 | value = offset - value; |
| 136 | } else { |
| 137 | value += offset; |
| 138 | if (value > s->maxdata) |
| 139 | value = s->maxdata; /* positive saturation */ |
| 140 | } |
| 141 | |
| 142 | return value; |
| 143 | } |
| 144 | |
| 145 | static unsigned short fake_flatline(struct comedi_device *dev, |
| 146 | unsigned int range_index, |
| 147 | unsigned int current_time) |
| 148 | { |
| 149 | return dev->read_subdev->maxdata / 2; |
| 150 | } |
| 151 | |
| 152 | /* generates a different waveform depending on what channel is read */ |
| 153 | static unsigned short fake_waveform(struct comedi_device *dev, |
| 154 | unsigned int channel, unsigned int range, |
| 155 | unsigned int current_time) |
| 156 | { |
| 157 | enum { |
| 158 | SAWTOOTH_CHAN, |
| 159 | SQUARE_CHAN, |
| 160 | }; |
| 161 | switch (channel) { |
| 162 | case SAWTOOTH_CHAN: |
| 163 | return fake_sawtooth(dev, range, current_time); |
| 164 | case SQUARE_CHAN: |
| 165 | return fake_squarewave(dev, range, current_time); |
| 166 | default: |
| 167 | break; |
| 168 | } |
| 169 | |
| 170 | return fake_flatline(dev, range, current_time); |
| 171 | } |
| 172 | |
| 173 | /* |
| 174 | * This is the background routine used to generate arbitrary data. |
| 175 | * It should run in the background; therefore it is scheduled by |
| 176 | * a timer mechanism. |
| 177 | */ |
| 178 | static void waveform_ai_interrupt(unsigned long arg) |
| 179 | { |
| 180 | struct comedi_device *dev = (struct comedi_device *)arg; |
| 181 | struct waveform_private *devpriv = dev->private; |
| 182 | struct comedi_subdevice *s = dev->read_subdev; |
| 183 | struct comedi_async *async = s->async; |
| 184 | struct comedi_cmd *cmd = &async->cmd; |
| 185 | unsigned int i, j; |
| 186 | unsigned long elapsed_time; |
| 187 | unsigned int num_scans; |
| 188 | |
| 189 | /* check command is still active */ |
| 190 | if (!test_bit(WAVEFORM_AI_RUNNING, &devpriv->state_bits)) |
| 191 | return; |
| 192 | |
| 193 | elapsed_time = ktime_to_us(ktime_get()) - devpriv->ai_last_scan_time; |
| 194 | num_scans = elapsed_time / devpriv->ai_scan_period; |
| 195 | |
| 196 | num_scans = comedi_nscans_left(s, num_scans); |
| 197 | for (i = 0; i < num_scans; i++) { |
| 198 | unsigned int scan_remain_period = devpriv->ai_scan_period; |
| 199 | |
| 200 | for (j = 0; j < cmd->chanlist_len; j++) { |
| 201 | unsigned short sample; |
| 202 | |
| 203 | if (devpriv->wf_current >= devpriv->wf_period) |
| 204 | devpriv->wf_current %= devpriv->wf_period; |
| 205 | sample = fake_waveform(dev, CR_CHAN(cmd->chanlist[j]), |
| 206 | CR_RANGE(cmd->chanlist[j]), |
| 207 | devpriv->wf_current); |
| 208 | comedi_buf_write_samples(s, &sample, 1); |
| 209 | devpriv->wf_current += devpriv->ai_convert_period; |
| 210 | scan_remain_period -= devpriv->ai_convert_period; |
| 211 | } |
| 212 | devpriv->wf_current += scan_remain_period; |
| 213 | devpriv->ai_last_scan_time += devpriv->ai_scan_period; |
| 214 | } |
| 215 | if (devpriv->wf_current >= devpriv->wf_period) |
| 216 | devpriv->wf_current %= devpriv->wf_period; |
| 217 | |
| 218 | if (cmd->stop_src == TRIG_COUNT && async->scans_done >= cmd->stop_arg) |
| 219 | async->events |= COMEDI_CB_EOA; |
| 220 | else |
| 221 | mod_timer(&devpriv->ai_timer, jiffies + 1); |
| 222 | |
| 223 | comedi_handle_events(dev, s); |
| 224 | } |
| 225 | |
| 226 | static int waveform_ai_cmdtest(struct comedi_device *dev, |
| 227 | struct comedi_subdevice *s, |
| 228 | struct comedi_cmd *cmd) |
| 229 | { |
| 230 | int err = 0; |
| 231 | unsigned int arg, limit; |
| 232 | |
| 233 | /* Step 1 : check if triggers are trivially valid */ |
| 234 | |
| 235 | err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW); |
| 236 | err |= comedi_check_trigger_src(&cmd->scan_begin_src, |
| 237 | TRIG_FOLLOW | TRIG_TIMER); |
| 238 | err |= comedi_check_trigger_src(&cmd->convert_src, |
| 239 | TRIG_NOW | TRIG_TIMER); |
| 240 | err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT); |
| 241 | err |= comedi_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE); |
| 242 | |
| 243 | if (err) |
| 244 | return 1; |
| 245 | |
| 246 | /* Step 2a : make sure trigger sources are unique */ |
| 247 | |
| 248 | err |= comedi_check_trigger_is_unique(cmd->convert_src); |
| 249 | err |= comedi_check_trigger_is_unique(cmd->stop_src); |
| 250 | |
| 251 | /* Step 2b : and mutually compatible */ |
| 252 | |
| 253 | if (cmd->scan_begin_src == TRIG_FOLLOW && cmd->convert_src == TRIG_NOW) |
| 254 | err |= -EINVAL; /* scan period would be 0 */ |
| 255 | |
| 256 | if (err) |
| 257 | return 2; |
| 258 | |
| 259 | /* Step 3: check if arguments are trivially valid */ |
| 260 | |
| 261 | err |= comedi_check_trigger_arg_is(&cmd->start_arg, 0); |
| 262 | |
| 263 | if (cmd->convert_src == TRIG_NOW) { |
| 264 | err |= comedi_check_trigger_arg_is(&cmd->convert_arg, 0); |
| 265 | } else { /* cmd->convert_src == TRIG_TIMER */ |
| 266 | if (cmd->scan_begin_src == TRIG_FOLLOW) { |
| 267 | err |= comedi_check_trigger_arg_min(&cmd->convert_arg, |
| 268 | NSEC_PER_USEC); |
| 269 | } |
| 270 | } |
| 271 | |
| 272 | if (cmd->scan_begin_src == TRIG_FOLLOW) { |
| 273 | err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, 0); |
| 274 | } else { /* cmd->scan_begin_src == TRIG_TIMER */ |
| 275 | err |= comedi_check_trigger_arg_min(&cmd->scan_begin_arg, |
| 276 | NSEC_PER_USEC); |
| 277 | } |
| 278 | |
| 279 | err |= comedi_check_trigger_arg_min(&cmd->chanlist_len, 1); |
| 280 | err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg, |
| 281 | cmd->chanlist_len); |
| 282 | |
| 283 | if (cmd->stop_src == TRIG_COUNT) |
| 284 | err |= comedi_check_trigger_arg_min(&cmd->stop_arg, 1); |
| 285 | else /* cmd->stop_src == TRIG_NONE */ |
| 286 | err |= comedi_check_trigger_arg_is(&cmd->stop_arg, 0); |
| 287 | |
| 288 | if (err) |
| 289 | return 3; |
| 290 | |
| 291 | /* step 4: fix up any arguments */ |
| 292 | |
| 293 | if (cmd->convert_src == TRIG_TIMER) { |
| 294 | /* round convert_arg to nearest microsecond */ |
| 295 | arg = cmd->convert_arg; |
| 296 | arg = min(arg, |
| 297 | rounddown(UINT_MAX, (unsigned int)NSEC_PER_USEC)); |
| 298 | arg = NSEC_PER_USEC * DIV_ROUND_CLOSEST(arg, NSEC_PER_USEC); |
| 299 | if (cmd->scan_begin_arg == TRIG_TIMER) { |
| 300 | /* limit convert_arg to keep scan_begin_arg in range */ |
| 301 | limit = UINT_MAX / cmd->scan_end_arg; |
| 302 | limit = rounddown(limit, (unsigned int)NSEC_PER_SEC); |
| 303 | arg = min(arg, limit); |
| 304 | } |
| 305 | err |= comedi_check_trigger_arg_is(&cmd->convert_arg, arg); |
| 306 | } |
| 307 | |
| 308 | if (cmd->scan_begin_src == TRIG_TIMER) { |
| 309 | /* round scan_begin_arg to nearest microsecond */ |
| 310 | arg = cmd->scan_begin_arg; |
| 311 | arg = min(arg, |
| 312 | rounddown(UINT_MAX, (unsigned int)NSEC_PER_USEC)); |
| 313 | arg = NSEC_PER_USEC * DIV_ROUND_CLOSEST(arg, NSEC_PER_USEC); |
| 314 | if (cmd->convert_src == TRIG_TIMER) { |
| 315 | /* but ensure scan_begin_arg is large enough */ |
| 316 | arg = max(arg, cmd->convert_arg * cmd->scan_end_arg); |
| 317 | } |
| 318 | err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, arg); |
| 319 | } |
| 320 | |
| 321 | if (err) |
| 322 | return 4; |
| 323 | |
| 324 | return 0; |
| 325 | } |
| 326 | |
| 327 | static int waveform_ai_cmd(struct comedi_device *dev, |
| 328 | struct comedi_subdevice *s) |
| 329 | { |
| 330 | struct waveform_private *devpriv = dev->private; |
| 331 | struct comedi_cmd *cmd = &s->async->cmd; |
| 332 | u64 wf_current; |
| 333 | |
| 334 | if (cmd->flags & CMDF_PRIORITY) { |
| 335 | dev_err(dev->class_dev, |
| 336 | "commands at RT priority not supported in this driver\n"); |
| 337 | return -1; |
| 338 | } |
| 339 | |
| 340 | if (cmd->convert_src == TRIG_NOW) |
| 341 | devpriv->ai_convert_period = 0; |
| 342 | else /* cmd->convert_src == TRIG_TIMER */ |
| 343 | devpriv->ai_convert_period = cmd->convert_arg / NSEC_PER_USEC; |
| 344 | |
| 345 | if (cmd->scan_begin_src == TRIG_FOLLOW) { |
| 346 | devpriv->ai_scan_period = devpriv->ai_convert_period * |
| 347 | cmd->scan_end_arg; |
| 348 | } else { /* cmd->scan_begin_src == TRIG_TIMER */ |
| 349 | devpriv->ai_scan_period = cmd->scan_begin_arg / NSEC_PER_USEC; |
| 350 | } |
| 351 | |
| 352 | devpriv->ai_last_scan_time = ktime_to_us(ktime_get()); |
| 353 | /* Determine time within waveform period. */ |
| 354 | wf_current = devpriv->ai_last_scan_time; |
| 355 | devpriv->wf_current = do_div(wf_current, devpriv->wf_period); |
| 356 | |
| 357 | devpriv->ai_timer.expires = jiffies + 1; |
| 358 | /* mark command as active */ |
| 359 | smp_mb__before_atomic(); |
| 360 | set_bit(WAVEFORM_AI_RUNNING, &devpriv->state_bits); |
| 361 | smp_mb__after_atomic(); |
| 362 | add_timer(&devpriv->ai_timer); |
| 363 | return 0; |
| 364 | } |
| 365 | |
| 366 | static int waveform_ai_cancel(struct comedi_device *dev, |
| 367 | struct comedi_subdevice *s) |
| 368 | { |
| 369 | struct waveform_private *devpriv = dev->private; |
| 370 | |
| 371 | /* mark command as no longer active */ |
| 372 | clear_bit(WAVEFORM_AI_RUNNING, &devpriv->state_bits); |
| 373 | smp_mb__after_atomic(); |
| 374 | /* cannot call del_timer_sync() as may be called from timer routine */ |
| 375 | del_timer(&devpriv->ai_timer); |
| 376 | return 0; |
| 377 | } |
| 378 | |
| 379 | static int waveform_ai_insn_read(struct comedi_device *dev, |
| 380 | struct comedi_subdevice *s, |
| 381 | struct comedi_insn *insn, unsigned int *data) |
| 382 | { |
| 383 | struct waveform_private *devpriv = dev->private; |
| 384 | int i, chan = CR_CHAN(insn->chanspec); |
| 385 | |
| 386 | for (i = 0; i < insn->n; i++) |
| 387 | data[i] = devpriv->ao_loopbacks[chan]; |
| 388 | |
| 389 | return insn->n; |
| 390 | } |
| 391 | |
| 392 | static int waveform_ao_insn_write(struct comedi_device *dev, |
| 393 | struct comedi_subdevice *s, |
| 394 | struct comedi_insn *insn, unsigned int *data) |
| 395 | { |
| 396 | struct waveform_private *devpriv = dev->private; |
| 397 | int i, chan = CR_CHAN(insn->chanspec); |
| 398 | |
| 399 | for (i = 0; i < insn->n; i++) |
| 400 | devpriv->ao_loopbacks[chan] = data[i]; |
| 401 | |
| 402 | return insn->n; |
| 403 | } |
| 404 | |
| 405 | static int waveform_attach(struct comedi_device *dev, |
| 406 | struct comedi_devconfig *it) |
| 407 | { |
| 408 | struct waveform_private *devpriv; |
| 409 | struct comedi_subdevice *s; |
| 410 | int amplitude = it->options[0]; |
| 411 | int period = it->options[1]; |
| 412 | int i; |
| 413 | int ret; |
| 414 | |
| 415 | devpriv = comedi_alloc_devpriv(dev, sizeof(*devpriv)); |
| 416 | if (!devpriv) |
| 417 | return -ENOMEM; |
| 418 | |
| 419 | /* set default amplitude and period */ |
| 420 | if (amplitude <= 0) |
| 421 | amplitude = 1000000; /* 1 volt */ |
| 422 | if (period <= 0) |
| 423 | period = 100000; /* 0.1 sec */ |
| 424 | |
| 425 | devpriv->wf_amplitude = amplitude; |
| 426 | devpriv->wf_period = period; |
| 427 | |
| 428 | ret = comedi_alloc_subdevices(dev, 2); |
| 429 | if (ret) |
| 430 | return ret; |
| 431 | |
| 432 | s = &dev->subdevices[0]; |
| 433 | dev->read_subdev = s; |
| 434 | /* analog input subdevice */ |
| 435 | s->type = COMEDI_SUBD_AI; |
| 436 | s->subdev_flags = SDF_READABLE | SDF_GROUND | SDF_CMD_READ; |
| 437 | s->n_chan = N_CHANS; |
| 438 | s->maxdata = 0xffff; |
| 439 | s->range_table = &waveform_ai_ranges; |
| 440 | s->len_chanlist = s->n_chan * 2; |
| 441 | s->insn_read = waveform_ai_insn_read; |
| 442 | s->do_cmd = waveform_ai_cmd; |
| 443 | s->do_cmdtest = waveform_ai_cmdtest; |
| 444 | s->cancel = waveform_ai_cancel; |
| 445 | |
| 446 | s = &dev->subdevices[1]; |
| 447 | dev->write_subdev = s; |
| 448 | /* analog output subdevice (loopback) */ |
| 449 | s->type = COMEDI_SUBD_AO; |
| 450 | s->subdev_flags = SDF_WRITABLE | SDF_GROUND; |
| 451 | s->n_chan = N_CHANS; |
| 452 | s->maxdata = 0xffff; |
| 453 | s->range_table = &waveform_ai_ranges; |
| 454 | s->insn_write = waveform_ao_insn_write; |
| 455 | |
| 456 | /* Our default loopback value is just a 0V flatline */ |
| 457 | for (i = 0; i < s->n_chan; i++) |
| 458 | devpriv->ao_loopbacks[i] = s->maxdata / 2; |
| 459 | |
| 460 | setup_timer(&devpriv->ai_timer, waveform_ai_interrupt, |
| 461 | (unsigned long)dev); |
| 462 | |
| 463 | dev_info(dev->class_dev, |
| 464 | "%s: %u microvolt, %u microsecond waveform attached\n", |
| 465 | dev->board_name, |
| 466 | devpriv->wf_amplitude, devpriv->wf_period); |
| 467 | |
| 468 | return 0; |
| 469 | } |
| 470 | |
| 471 | static void waveform_detach(struct comedi_device *dev) |
| 472 | { |
| 473 | struct waveform_private *devpriv = dev->private; |
| 474 | |
| 475 | if (devpriv) |
| 476 | del_timer_sync(&devpriv->ai_timer); |
| 477 | } |
| 478 | |
| 479 | static struct comedi_driver waveform_driver = { |
| 480 | .driver_name = "comedi_test", |
| 481 | .module = THIS_MODULE, |
| 482 | .attach = waveform_attach, |
| 483 | .detach = waveform_detach, |
| 484 | }; |
| 485 | module_comedi_driver(waveform_driver); |
| 486 | |
| 487 | MODULE_AUTHOR("Comedi http://www.comedi.org"); |
| 488 | MODULE_DESCRIPTION("Comedi low-level driver"); |
| 489 | MODULE_LICENSE("GPL"); |