2 comedi/drivers/comedi_test.c
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.
9 Copyright (C) 2002 Joachim Wuttke <Joachim.Wuttke@icn.siemens.de>
10 Copyright (C) 2002 Frank Mori Hess <fmhess@users.sourceforge.net>
12 COMEDI - Linux Control and Measurement Device Interface
13 Copyright (C) 2000 David A. Schleef <ds@schleef.org>
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.
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.
25 You should have received a copy of the GNU General Public License
26 along with this program; if not, write to the Free Software
27 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
29 ************************************************************************/
32 Description: generates fake waveforms
33 Author: Joachim Wuttke <Joachim.Wuttke@icn.siemens.de>, Frank Mori Hess
34 <fmhess@users.sourceforge.net>, ds
37 Updated: Sat, 16 Mar 2002 17:34:48 -0800
39 This driver is mainly for testing purposes, but can also be used to
40 generate sample waveforms on systems that don't have data acquisition
43 Configuration options:
44 [0] - Amplitude in microvolts for fake waveforms (default 1 volt)
45 [1] - Period in microseconds for fake waveforms (default 0.1 sec)
47 Generates a sawtooth wave on channel 0, square wave on channel 1, additional
48 waveforms could be added to other channels (currently they return flatline
53 #include "../comedidev.h"
55 #include <asm/div64.h>
57 #include "comedi_fc.h"
58 #include <linux/timer.h>
62 /* Data unique to this driver */
63 struct waveform_private {
64 struct timer_list timer;
65 struct timeval last; /* time at which last timer interrupt occurred */
66 unsigned int uvolt_amplitude; /* waveform amplitude in microvolts */
67 unsigned long usec_period; /* waveform period in microseconds */
68 unsigned long usec_current; /* current time (modulo waveform period) */
69 unsigned long usec_remainder; /* usec since last scan; */
70 unsigned long ai_count; /* number of conversions remaining */
71 unsigned int scan_period; /* scan period in usec */
72 unsigned int convert_period; /* conversion period in usec */
73 unsigned timer_running:1;
74 unsigned int ao_loopbacks[N_CHANS];
77 /* 1000 nanosec in a microsec */
78 static const int nano_per_micro = 1000;
80 /* fake analog input ranges */
81 static const struct comedi_lrange waveform_ai_ranges = {
89 static short fake_sawtooth(struct comedi_device *dev, unsigned int range_index,
90 unsigned long current_time)
92 struct waveform_private *devpriv = dev->private;
93 struct comedi_subdevice *s = dev->read_subdev;
94 unsigned int offset = s->maxdata / 2;
96 const struct comedi_krange *krange =
97 &s->range_table->range[range_index];
100 binary_amplitude = s->maxdata;
101 binary_amplitude *= devpriv->uvolt_amplitude;
102 do_div(binary_amplitude, krange->max - krange->min);
104 current_time %= devpriv->usec_period;
105 value = current_time;
106 value *= binary_amplitude * 2;
107 do_div(value, devpriv->usec_period);
108 value -= binary_amplitude; /* get rid of sawtooth's dc offset */
110 return offset + value;
113 static short fake_squarewave(struct comedi_device *dev,
114 unsigned int range_index,
115 unsigned long current_time)
117 struct waveform_private *devpriv = dev->private;
118 struct comedi_subdevice *s = dev->read_subdev;
119 unsigned int offset = s->maxdata / 2;
121 const struct comedi_krange *krange =
122 &s->range_table->range[range_index];
123 current_time %= devpriv->usec_period;
126 value *= devpriv->uvolt_amplitude;
127 do_div(value, krange->max - krange->min);
129 if (current_time < devpriv->usec_period / 2)
132 return offset + value;
135 static short fake_flatline(struct comedi_device *dev, unsigned int range_index,
136 unsigned long current_time)
138 return dev->read_subdev->maxdata / 2;
141 /* generates a different waveform depending on what channel is read */
142 static short fake_waveform(struct comedi_device *dev, unsigned int channel,
143 unsigned int range, unsigned long current_time)
151 return fake_sawtooth(dev, range, current_time);
154 return fake_squarewave(dev, range, current_time);
160 return fake_flatline(dev, range, current_time);
164 This is the background routine used to generate arbitrary data.
165 It should run in the background; therefore it is scheduled by
168 static void waveform_ai_interrupt(unsigned long arg)
170 struct comedi_device *dev = (struct comedi_device *)arg;
171 struct waveform_private *devpriv = dev->private;
172 struct comedi_async *async = dev->read_subdev->async;
173 struct comedi_cmd *cmd = &async->cmd;
175 /* all times in microsec */
176 unsigned long elapsed_time;
177 unsigned int num_scans;
180 do_gettimeofday(&now);
183 1000000 * (now.tv_sec - devpriv->last.tv_sec) + now.tv_usec -
184 devpriv->last.tv_usec;
187 (devpriv->usec_remainder + elapsed_time) / devpriv->scan_period;
188 devpriv->usec_remainder =
189 (devpriv->usec_remainder + elapsed_time) % devpriv->scan_period;
192 for (i = 0; i < num_scans; i++) {
193 for (j = 0; j < cmd->chanlist_len; j++) {
194 cfc_write_to_buffer(dev->read_subdev,
203 devpriv->scan_period +
209 if (cmd->stop_src == TRIG_COUNT
210 && devpriv->ai_count >= cmd->stop_arg) {
211 async->events |= COMEDI_CB_EOA;
216 devpriv->usec_current += elapsed_time;
217 devpriv->usec_current %= devpriv->usec_period;
219 if ((async->events & COMEDI_CB_EOA) == 0 && devpriv->timer_running)
220 mod_timer(&devpriv->timer, jiffies + 1);
222 del_timer(&devpriv->timer);
224 comedi_event(dev, dev->read_subdev);
227 static int waveform_ai_cmdtest(struct comedi_device *dev,
228 struct comedi_subdevice *s,
229 struct comedi_cmd *cmd)
234 /* Step 1 : check if triggers are trivially valid */
236 err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
237 err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_TIMER);
238 err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW | TRIG_TIMER);
239 err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
240 err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
245 /* Step 2a : make sure trigger sources are unique */
247 err |= cfc_check_trigger_is_unique(cmd->convert_src);
248 err |= cfc_check_trigger_is_unique(cmd->stop_src);
250 /* Step 2b : and mutually compatible */
255 /* step 3: make sure arguments are trivially compatible */
257 if (cmd->start_arg != 0) {
261 if (cmd->convert_src == TRIG_NOW) {
262 if (cmd->convert_arg != 0) {
263 cmd->convert_arg = 0;
267 if (cmd->scan_begin_src == TRIG_TIMER) {
268 if (cmd->scan_begin_arg < nano_per_micro) {
269 cmd->scan_begin_arg = nano_per_micro;
272 if (cmd->convert_src == TRIG_TIMER &&
273 cmd->scan_begin_arg <
274 cmd->convert_arg * cmd->chanlist_len) {
275 cmd->scan_begin_arg =
276 cmd->convert_arg * cmd->chanlist_len;
281 * XXX these checks are generic and should go in core if not there
284 if (!cmd->chanlist_len) {
285 cmd->chanlist_len = 1;
288 if (cmd->scan_end_arg != cmd->chanlist_len) {
289 cmd->scan_end_arg = cmd->chanlist_len;
293 if (cmd->stop_src == TRIG_COUNT) {
294 if (!cmd->stop_arg) {
298 } else { /* TRIG_NONE */
299 if (cmd->stop_arg != 0) {
308 /* step 4: fix up any arguments */
310 if (cmd->scan_begin_src == TRIG_TIMER) {
311 tmp = cmd->scan_begin_arg;
312 /* round to nearest microsec */
313 cmd->scan_begin_arg =
314 nano_per_micro * ((tmp +
315 (nano_per_micro / 2)) / nano_per_micro);
316 if (tmp != cmd->scan_begin_arg)
319 if (cmd->convert_src == TRIG_TIMER) {
320 tmp = cmd->convert_arg;
321 /* round to nearest microsec */
323 nano_per_micro * ((tmp +
324 (nano_per_micro / 2)) / nano_per_micro);
325 if (tmp != cmd->convert_arg)
335 static int waveform_ai_cmd(struct comedi_device *dev,
336 struct comedi_subdevice *s)
338 struct waveform_private *devpriv = dev->private;
339 struct comedi_cmd *cmd = &s->async->cmd;
341 if (cmd->flags & TRIG_RT) {
343 "commands at RT priority not supported in this driver");
347 devpriv->timer_running = 1;
348 devpriv->ai_count = 0;
349 devpriv->scan_period = cmd->scan_begin_arg / nano_per_micro;
351 if (cmd->convert_src == TRIG_NOW)
352 devpriv->convert_period = 0;
353 else if (cmd->convert_src == TRIG_TIMER)
354 devpriv->convert_period = cmd->convert_arg / nano_per_micro;
356 comedi_error(dev, "bug setting conversion period");
360 do_gettimeofday(&devpriv->last);
361 devpriv->usec_current = devpriv->last.tv_usec % devpriv->usec_period;
362 devpriv->usec_remainder = 0;
364 devpriv->timer.expires = jiffies + 1;
365 add_timer(&devpriv->timer);
369 static int waveform_ai_cancel(struct comedi_device *dev,
370 struct comedi_subdevice *s)
372 struct waveform_private *devpriv = dev->private;
374 devpriv->timer_running = 0;
375 del_timer(&devpriv->timer);
379 static int waveform_ai_insn_read(struct comedi_device *dev,
380 struct comedi_subdevice *s,
381 struct comedi_insn *insn, unsigned int *data)
383 struct waveform_private *devpriv = dev->private;
384 int i, chan = CR_CHAN(insn->chanspec);
386 for (i = 0; i < insn->n; i++)
387 data[i] = devpriv->ao_loopbacks[chan];
392 static int waveform_ao_insn_write(struct comedi_device *dev,
393 struct comedi_subdevice *s,
394 struct comedi_insn *insn, unsigned int *data)
396 struct waveform_private *devpriv = dev->private;
397 int i, chan = CR_CHAN(insn->chanspec);
399 for (i = 0; i < insn->n; i++)
400 devpriv->ao_loopbacks[chan] = data[i];
405 static int waveform_attach(struct comedi_device *dev,
406 struct comedi_devconfig *it)
408 struct waveform_private *devpriv;
409 struct comedi_subdevice *s;
410 int amplitude = it->options[0];
411 int period = it->options[1];
415 dev->board_name = dev->driver->driver_name;
417 ret = alloc_private(dev, sizeof(*devpriv));
420 devpriv = dev->private;
422 /* set default amplitude and period */
424 amplitude = 1000000; /* 1 volt */
426 period = 100000; /* 0.1 sec */
428 devpriv->uvolt_amplitude = amplitude;
429 devpriv->usec_period = period;
431 ret = comedi_alloc_subdevices(dev, 2);
435 s = &dev->subdevices[0];
436 dev->read_subdev = s;
437 /* analog input subdevice */
438 s->type = COMEDI_SUBD_AI;
439 s->subdev_flags = SDF_READABLE | SDF_GROUND | SDF_CMD_READ;
442 s->range_table = &waveform_ai_ranges;
443 s->len_chanlist = s->n_chan * 2;
444 s->insn_read = waveform_ai_insn_read;
445 s->do_cmd = waveform_ai_cmd;
446 s->do_cmdtest = waveform_ai_cmdtest;
447 s->cancel = waveform_ai_cancel;
449 s = &dev->subdevices[1];
450 dev->write_subdev = s;
451 /* analog output subdevice (loopback) */
452 s->type = COMEDI_SUBD_AO;
453 s->subdev_flags = SDF_WRITEABLE | SDF_GROUND;
456 s->range_table = &waveform_ai_ranges;
457 s->len_chanlist = s->n_chan * 2;
458 s->insn_write = waveform_ao_insn_write;
460 s->do_cmdtest = NULL;
463 /* Our default loopback value is just a 0V flatline */
464 for (i = 0; i < s->n_chan; i++)
465 devpriv->ao_loopbacks[i] = s->maxdata / 2;
467 init_timer(&(devpriv->timer));
468 devpriv->timer.function = waveform_ai_interrupt;
469 devpriv->timer.data = (unsigned long)dev;
471 dev_info(dev->class_dev,
472 "%s: %i microvolt, %li microsecond waveform attached\n",
474 devpriv->uvolt_amplitude, devpriv->usec_period);
479 static void waveform_detach(struct comedi_device *dev)
481 struct waveform_private *devpriv = dev->private;
484 waveform_ai_cancel(dev, dev->read_subdev);
487 static struct comedi_driver waveform_driver = {
488 .driver_name = "comedi_test",
489 .module = THIS_MODULE,
490 .attach = waveform_attach,
491 .detach = waveform_detach,
493 module_comedi_driver(waveform_driver);
495 MODULE_AUTHOR("Comedi http://www.comedi.org");
496 MODULE_DESCRIPTION("Comedi low-level driver");
497 MODULE_LICENSE("GPL");