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>
60 /* Board descriptions */
61 struct waveform_board {
70 static const struct waveform_board waveform_boards[] = {
72 .name = "comedi_test",
79 #define thisboard ((const struct waveform_board *)dev->board_ptr)
81 /* Data unique to this driver */
82 struct waveform_private {
83 struct timer_list timer;
84 struct timeval last; /* time at which last timer interrupt occured */
85 unsigned int uvolt_amplitude; /* waveform amplitude in microvolts */
86 unsigned long usec_period; /* waveform period in microseconds */
87 unsigned long usec_current; /* current time (modulo waveform period) */
88 unsigned long usec_remainder; /* usec since last scan; */
89 unsigned long ai_count; /* number of conversions remaining */
90 unsigned int scan_period; /* scan period in usec */
91 unsigned int convert_period; /* conversion period in usec */
92 unsigned timer_running:1;
93 unsigned int ao_loopbacks[N_CHANS];
95 #define devpriv ((struct waveform_private *)dev->private)
97 static int waveform_attach(struct comedi_device *dev,
98 struct comedi_devconfig *it);
99 static int waveform_detach(struct comedi_device *dev);
100 static struct comedi_driver driver_waveform = {
101 .driver_name = "comedi_test",
102 .module = THIS_MODULE,
103 .attach = waveform_attach,
104 .detach = waveform_detach,
105 .board_name = &waveform_boards[0].name,
106 .offset = sizeof(struct waveform_board),
107 .num_names = ARRAY_SIZE(waveform_boards),
110 static int __init driver_waveform_init_module(void)
112 return comedi_driver_register(&driver_waveform);
115 static void __exit driver_waveform_cleanup_module(void)
117 comedi_driver_unregister(&driver_waveform);
120 module_init(driver_waveform_init_module);
121 module_exit(driver_waveform_cleanup_module);
123 static int waveform_ai_cmdtest(struct comedi_device *dev,
124 struct comedi_subdevice *s,
125 struct comedi_cmd *cmd);
126 static int waveform_ai_cmd(struct comedi_device *dev,
127 struct comedi_subdevice *s);
128 static int waveform_ai_cancel(struct comedi_device *dev,
129 struct comedi_subdevice *s);
130 static int waveform_ai_insn_read(struct comedi_device *dev,
131 struct comedi_subdevice *s,
132 struct comedi_insn *insn, unsigned int *data);
133 static int waveform_ao_insn_write(struct comedi_device *dev,
134 struct comedi_subdevice *s,
135 struct comedi_insn *insn, unsigned int *data);
136 static short fake_sawtooth(struct comedi_device *dev, unsigned int range,
137 unsigned long current_time);
138 static short fake_squarewave(struct comedi_device *dev, unsigned int range,
139 unsigned long current_time);
140 static short fake_flatline(struct comedi_device *dev, unsigned int range,
141 unsigned long current_time);
142 static short fake_waveform(struct comedi_device *dev, unsigned int channel,
143 unsigned int range, unsigned long current_time);
145 /* 1000 nanosec in a microsec */
146 static const int nano_per_micro = 1000;
148 /* fake analog input ranges */
149 static const struct comedi_lrange waveform_ai_ranges = {
158 This is the background routine used to generate arbitrary data.
159 It should run in the background; therefore it is scheduled by
162 static void waveform_ai_interrupt(unsigned long arg)
164 struct comedi_device *dev = (struct comedi_device *)arg;
165 struct comedi_async *async = dev->read_subdev->async;
166 struct comedi_cmd *cmd = &async->cmd;
168 /* all times in microsec */
169 unsigned long elapsed_time;
170 unsigned int num_scans;
173 do_gettimeofday(&now);
176 1000000 * (now.tv_sec - devpriv->last.tv_sec) + now.tv_usec -
177 devpriv->last.tv_usec;
180 (devpriv->usec_remainder + elapsed_time) / devpriv->scan_period;
181 devpriv->usec_remainder =
182 (devpriv->usec_remainder + elapsed_time) % devpriv->scan_period;
185 for (i = 0; i < num_scans; i++) {
186 for (j = 0; j < cmd->chanlist_len; j++) {
187 cfc_write_to_buffer(dev->read_subdev,
196 devpriv->scan_period +
202 if (cmd->stop_src == TRIG_COUNT
203 && devpriv->ai_count >= cmd->stop_arg) {
204 async->events |= COMEDI_CB_EOA;
209 devpriv->usec_current += elapsed_time;
210 devpriv->usec_current %= devpriv->usec_period;
212 if ((async->events & COMEDI_CB_EOA) == 0 && devpriv->timer_running)
213 mod_timer(&devpriv->timer, jiffies + 1);
215 del_timer(&devpriv->timer);
217 comedi_event(dev, dev->read_subdev);
220 static int waveform_attach(struct comedi_device *dev,
221 struct comedi_devconfig *it)
223 struct comedi_subdevice *s;
224 int amplitude = it->options[0];
225 int period = it->options[1];
228 dev->board_name = thisboard->name;
230 if (alloc_private(dev, sizeof(struct waveform_private)) < 0)
233 /* set default amplitude and period */
235 amplitude = 1000000; /* 1 volt */
237 period = 100000; /* 0.1 sec */
239 devpriv->uvolt_amplitude = amplitude;
240 devpriv->usec_period = period;
242 dev->n_subdevices = 2;
243 if (alloc_subdevices(dev, dev->n_subdevices) < 0)
246 s = dev->subdevices + 0;
247 dev->read_subdev = s;
248 /* analog input subdevice */
249 s->type = COMEDI_SUBD_AI;
250 s->subdev_flags = SDF_READABLE | SDF_GROUND | SDF_CMD_READ;
251 s->n_chan = thisboard->ai_chans;
252 s->maxdata = (1 << thisboard->ai_bits) - 1;
253 s->range_table = &waveform_ai_ranges;
254 s->len_chanlist = s->n_chan * 2;
255 s->insn_read = waveform_ai_insn_read;
256 s->do_cmd = waveform_ai_cmd;
257 s->do_cmdtest = waveform_ai_cmdtest;
258 s->cancel = waveform_ai_cancel;
260 s = dev->subdevices + 1;
261 dev->write_subdev = s;
262 /* analog output subdevice (loopback) */
263 s->type = COMEDI_SUBD_AO;
264 s->subdev_flags = SDF_WRITEABLE | SDF_GROUND;
265 s->n_chan = thisboard->ai_chans;
266 s->maxdata = (1 << thisboard->ai_bits) - 1;
267 s->range_table = &waveform_ai_ranges;
268 s->len_chanlist = s->n_chan * 2;
269 s->insn_write = waveform_ao_insn_write;
271 s->do_cmdtest = NULL;
274 /* Our default loopback value is just a 0V flatline */
275 for (i = 0; i < s->n_chan; i++)
276 devpriv->ao_loopbacks[i] = s->maxdata / 2;
278 init_timer(&(devpriv->timer));
279 devpriv->timer.function = waveform_ai_interrupt;
280 devpriv->timer.data = (unsigned long)dev;
282 printk(KERN_INFO "comedi%d: comedi_test: "
283 "%i microvolt, %li microsecond waveform attached\n", dev->minor,
284 devpriv->uvolt_amplitude, devpriv->usec_period);
288 static int waveform_detach(struct comedi_device *dev)
290 printk("comedi%d: comedi_test: remove\n", dev->minor);
293 waveform_ai_cancel(dev, dev->read_subdev);
298 static int waveform_ai_cmdtest(struct comedi_device *dev,
299 struct comedi_subdevice *s,
300 struct comedi_cmd *cmd)
305 /* step 1: make sure trigger sources are trivially valid */
307 tmp = cmd->start_src;
308 cmd->start_src &= TRIG_NOW;
309 if (!cmd->start_src || tmp != cmd->start_src)
312 tmp = cmd->scan_begin_src;
313 cmd->scan_begin_src &= TRIG_TIMER;
314 if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
317 tmp = cmd->convert_src;
318 cmd->convert_src &= TRIG_NOW | TRIG_TIMER;
319 if (!cmd->convert_src || tmp != cmd->convert_src)
322 tmp = cmd->scan_end_src;
323 cmd->scan_end_src &= TRIG_COUNT;
324 if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
328 cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
329 if (!cmd->stop_src || tmp != cmd->stop_src)
336 * step 2: make sure trigger sources are unique and mutually compatible
339 if (cmd->convert_src != TRIG_NOW && cmd->convert_src != TRIG_TIMER)
341 if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
347 /* step 3: make sure arguments are trivially compatible */
349 if (cmd->start_arg != 0) {
353 if (cmd->convert_src == TRIG_NOW) {
354 if (cmd->convert_arg != 0) {
355 cmd->convert_arg = 0;
359 if (cmd->scan_begin_src == TRIG_TIMER) {
360 if (cmd->scan_begin_arg < nano_per_micro) {
361 cmd->scan_begin_arg = nano_per_micro;
364 if (cmd->convert_src == TRIG_TIMER &&
365 cmd->scan_begin_arg <
366 cmd->convert_arg * cmd->chanlist_len) {
367 cmd->scan_begin_arg =
368 cmd->convert_arg * cmd->chanlist_len;
373 * XXX these checks are generic and should go in core if not there
376 if (!cmd->chanlist_len) {
377 cmd->chanlist_len = 1;
380 if (cmd->scan_end_arg != cmd->chanlist_len) {
381 cmd->scan_end_arg = cmd->chanlist_len;
385 if (cmd->stop_src == TRIG_COUNT) {
386 if (!cmd->stop_arg) {
390 } else { /* TRIG_NONE */
391 if (cmd->stop_arg != 0) {
400 /* step 4: fix up any arguments */
402 if (cmd->scan_begin_src == TRIG_TIMER) {
403 tmp = cmd->scan_begin_arg;
404 /* round to nearest microsec */
405 cmd->scan_begin_arg =
406 nano_per_micro * ((tmp +
407 (nano_per_micro / 2)) / nano_per_micro);
408 if (tmp != cmd->scan_begin_arg)
411 if (cmd->convert_src == TRIG_TIMER) {
412 tmp = cmd->convert_arg;
413 /* round to nearest microsec */
415 nano_per_micro * ((tmp +
416 (nano_per_micro / 2)) / nano_per_micro);
417 if (tmp != cmd->convert_arg)
427 static int waveform_ai_cmd(struct comedi_device *dev,
428 struct comedi_subdevice *s)
430 struct comedi_cmd *cmd = &s->async->cmd;
432 if (cmd->flags & TRIG_RT) {
434 "commands at RT priority not supported in this driver");
438 devpriv->timer_running = 1;
439 devpriv->ai_count = 0;
440 devpriv->scan_period = cmd->scan_begin_arg / nano_per_micro;
442 if (cmd->convert_src == TRIG_NOW)
443 devpriv->convert_period = 0;
444 else if (cmd->convert_src == TRIG_TIMER)
445 devpriv->convert_period = cmd->convert_arg / nano_per_micro;
447 comedi_error(dev, "bug setting conversion period");
451 do_gettimeofday(&devpriv->last);
452 devpriv->usec_current = devpriv->last.tv_usec % devpriv->usec_period;
453 devpriv->usec_remainder = 0;
455 devpriv->timer.expires = jiffies + 1;
456 add_timer(&devpriv->timer);
460 static int waveform_ai_cancel(struct comedi_device *dev,
461 struct comedi_subdevice *s)
463 devpriv->timer_running = 0;
464 del_timer(&devpriv->timer);
468 static short fake_sawtooth(struct comedi_device *dev, unsigned int range_index,
469 unsigned long current_time)
471 struct comedi_subdevice *s = dev->read_subdev;
472 unsigned int offset = s->maxdata / 2;
474 const struct comedi_krange *krange =
475 &s->range_table->range[range_index];
476 u64 binary_amplitude;
478 binary_amplitude = s->maxdata;
479 binary_amplitude *= devpriv->uvolt_amplitude;
480 do_div(binary_amplitude, krange->max - krange->min);
482 current_time %= devpriv->usec_period;
483 value = current_time;
484 value *= binary_amplitude * 2;
485 do_div(value, devpriv->usec_period);
486 value -= binary_amplitude; /* get rid of sawtooth's dc offset */
488 return offset + value;
491 static short fake_squarewave(struct comedi_device *dev,
492 unsigned int range_index,
493 unsigned long current_time)
495 struct comedi_subdevice *s = dev->read_subdev;
496 unsigned int offset = s->maxdata / 2;
498 const struct comedi_krange *krange =
499 &s->range_table->range[range_index];
500 current_time %= devpriv->usec_period;
503 value *= devpriv->uvolt_amplitude;
504 do_div(value, krange->max - krange->min);
506 if (current_time < devpriv->usec_period / 2)
509 return offset + value;
512 static short fake_flatline(struct comedi_device *dev, unsigned int range_index,
513 unsigned long current_time)
515 return dev->read_subdev->maxdata / 2;
518 /* generates a different waveform depending on what channel is read */
519 static short fake_waveform(struct comedi_device *dev, unsigned int channel,
520 unsigned int range, unsigned long current_time)
528 return fake_sawtooth(dev, range, current_time);
531 return fake_squarewave(dev, range, current_time);
537 return fake_flatline(dev, range, current_time);
540 static int waveform_ai_insn_read(struct comedi_device *dev,
541 struct comedi_subdevice *s,
542 struct comedi_insn *insn, unsigned int *data)
544 int i, chan = CR_CHAN(insn->chanspec);
546 for (i = 0; i < insn->n; i++)
547 data[i] = devpriv->ao_loopbacks[chan];
552 static int waveform_ao_insn_write(struct comedi_device *dev,
553 struct comedi_subdevice *s,
554 struct comedi_insn *insn, unsigned int *data)
556 int i, chan = CR_CHAN(insn->chanspec);
558 for (i = 0; i < insn->n; i++)
559 devpriv->ao_loopbacks[chan] = data[i];
564 MODULE_AUTHOR("Comedi http://www.comedi.org");
565 MODULE_DESCRIPTION("Comedi low-level driver");
566 MODULE_LICENSE("GPL");