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 /* Data unique to this driver */
71 struct waveform_private {
72 struct timer_list timer;
73 struct timeval last; /* time at which last timer interrupt occurred */
74 unsigned int uvolt_amplitude; /* waveform amplitude in microvolts */
75 unsigned long usec_period; /* waveform period in microseconds */
76 unsigned long usec_current; /* current time (modulo waveform period) */
77 unsigned long usec_remainder; /* usec since last scan; */
78 unsigned long ai_count; /* number of conversions remaining */
79 unsigned int scan_period; /* scan period in usec */
80 unsigned int convert_period; /* conversion period in usec */
81 unsigned timer_running:1;
82 unsigned int ao_loopbacks[N_CHANS];
84 #define devpriv ((struct waveform_private *)dev->private)
86 /* 1000 nanosec in a microsec */
87 static const int nano_per_micro = 1000;
89 /* fake analog input ranges */
90 static const struct comedi_lrange waveform_ai_ranges = {
98 static short fake_sawtooth(struct comedi_device *dev, unsigned int range_index,
99 unsigned long current_time)
101 struct comedi_subdevice *s = dev->read_subdev;
102 unsigned int offset = s->maxdata / 2;
104 const struct comedi_krange *krange =
105 &s->range_table->range[range_index];
106 u64 binary_amplitude;
108 binary_amplitude = s->maxdata;
109 binary_amplitude *= devpriv->uvolt_amplitude;
110 do_div(binary_amplitude, krange->max - krange->min);
112 current_time %= devpriv->usec_period;
113 value = current_time;
114 value *= binary_amplitude * 2;
115 do_div(value, devpriv->usec_period);
116 value -= binary_amplitude; /* get rid of sawtooth's dc offset */
118 return offset + value;
121 static short fake_squarewave(struct comedi_device *dev,
122 unsigned int range_index,
123 unsigned long current_time)
125 struct comedi_subdevice *s = dev->read_subdev;
126 unsigned int offset = s->maxdata / 2;
128 const struct comedi_krange *krange =
129 &s->range_table->range[range_index];
130 current_time %= devpriv->usec_period;
133 value *= devpriv->uvolt_amplitude;
134 do_div(value, krange->max - krange->min);
136 if (current_time < devpriv->usec_period / 2)
139 return offset + value;
142 static short fake_flatline(struct comedi_device *dev, unsigned int range_index,
143 unsigned long current_time)
145 return dev->read_subdev->maxdata / 2;
148 /* generates a different waveform depending on what channel is read */
149 static short fake_waveform(struct comedi_device *dev, unsigned int channel,
150 unsigned int range, unsigned long current_time)
158 return fake_sawtooth(dev, range, current_time);
161 return fake_squarewave(dev, range, current_time);
167 return fake_flatline(dev, range, current_time);
171 This is the background routine used to generate arbitrary data.
172 It should run in the background; therefore it is scheduled by
175 static void waveform_ai_interrupt(unsigned long arg)
177 struct comedi_device *dev = (struct comedi_device *)arg;
178 struct comedi_async *async = dev->read_subdev->async;
179 struct comedi_cmd *cmd = &async->cmd;
181 /* all times in microsec */
182 unsigned long elapsed_time;
183 unsigned int num_scans;
186 do_gettimeofday(&now);
189 1000000 * (now.tv_sec - devpriv->last.tv_sec) + now.tv_usec -
190 devpriv->last.tv_usec;
193 (devpriv->usec_remainder + elapsed_time) / devpriv->scan_period;
194 devpriv->usec_remainder =
195 (devpriv->usec_remainder + elapsed_time) % devpriv->scan_period;
198 for (i = 0; i < num_scans; i++) {
199 for (j = 0; j < cmd->chanlist_len; j++) {
200 cfc_write_to_buffer(dev->read_subdev,
209 devpriv->scan_period +
215 if (cmd->stop_src == TRIG_COUNT
216 && devpriv->ai_count >= cmd->stop_arg) {
217 async->events |= COMEDI_CB_EOA;
222 devpriv->usec_current += elapsed_time;
223 devpriv->usec_current %= devpriv->usec_period;
225 if ((async->events & COMEDI_CB_EOA) == 0 && devpriv->timer_running)
226 mod_timer(&devpriv->timer, jiffies + 1);
228 del_timer(&devpriv->timer);
230 comedi_event(dev, dev->read_subdev);
233 static int waveform_ai_cmdtest(struct comedi_device *dev,
234 struct comedi_subdevice *s,
235 struct comedi_cmd *cmd)
240 /* step 1: make sure trigger sources are trivially valid */
242 tmp = cmd->start_src;
243 cmd->start_src &= TRIG_NOW;
244 if (!cmd->start_src || tmp != cmd->start_src)
247 tmp = cmd->scan_begin_src;
248 cmd->scan_begin_src &= TRIG_TIMER;
249 if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
252 tmp = cmd->convert_src;
253 cmd->convert_src &= TRIG_NOW | TRIG_TIMER;
254 if (!cmd->convert_src || tmp != cmd->convert_src)
257 tmp = cmd->scan_end_src;
258 cmd->scan_end_src &= TRIG_COUNT;
259 if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
263 cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
264 if (!cmd->stop_src || tmp != cmd->stop_src)
271 * step 2: make sure trigger sources are unique and mutually compatible
274 if (cmd->convert_src != TRIG_NOW && cmd->convert_src != TRIG_TIMER)
276 if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
282 /* step 3: make sure arguments are trivially compatible */
284 if (cmd->start_arg != 0) {
288 if (cmd->convert_src == TRIG_NOW) {
289 if (cmd->convert_arg != 0) {
290 cmd->convert_arg = 0;
294 if (cmd->scan_begin_src == TRIG_TIMER) {
295 if (cmd->scan_begin_arg < nano_per_micro) {
296 cmd->scan_begin_arg = nano_per_micro;
299 if (cmd->convert_src == TRIG_TIMER &&
300 cmd->scan_begin_arg <
301 cmd->convert_arg * cmd->chanlist_len) {
302 cmd->scan_begin_arg =
303 cmd->convert_arg * cmd->chanlist_len;
308 * XXX these checks are generic and should go in core if not there
311 if (!cmd->chanlist_len) {
312 cmd->chanlist_len = 1;
315 if (cmd->scan_end_arg != cmd->chanlist_len) {
316 cmd->scan_end_arg = cmd->chanlist_len;
320 if (cmd->stop_src == TRIG_COUNT) {
321 if (!cmd->stop_arg) {
325 } else { /* TRIG_NONE */
326 if (cmd->stop_arg != 0) {
335 /* step 4: fix up any arguments */
337 if (cmd->scan_begin_src == TRIG_TIMER) {
338 tmp = cmd->scan_begin_arg;
339 /* round to nearest microsec */
340 cmd->scan_begin_arg =
341 nano_per_micro * ((tmp +
342 (nano_per_micro / 2)) / nano_per_micro);
343 if (tmp != cmd->scan_begin_arg)
346 if (cmd->convert_src == TRIG_TIMER) {
347 tmp = cmd->convert_arg;
348 /* round to nearest microsec */
350 nano_per_micro * ((tmp +
351 (nano_per_micro / 2)) / nano_per_micro);
352 if (tmp != cmd->convert_arg)
362 static int waveform_ai_cmd(struct comedi_device *dev,
363 struct comedi_subdevice *s)
365 struct comedi_cmd *cmd = &s->async->cmd;
367 if (cmd->flags & TRIG_RT) {
369 "commands at RT priority not supported in this driver");
373 devpriv->timer_running = 1;
374 devpriv->ai_count = 0;
375 devpriv->scan_period = cmd->scan_begin_arg / nano_per_micro;
377 if (cmd->convert_src == TRIG_NOW)
378 devpriv->convert_period = 0;
379 else if (cmd->convert_src == TRIG_TIMER)
380 devpriv->convert_period = cmd->convert_arg / nano_per_micro;
382 comedi_error(dev, "bug setting conversion period");
386 do_gettimeofday(&devpriv->last);
387 devpriv->usec_current = devpriv->last.tv_usec % devpriv->usec_period;
388 devpriv->usec_remainder = 0;
390 devpriv->timer.expires = jiffies + 1;
391 add_timer(&devpriv->timer);
395 static int waveform_ai_cancel(struct comedi_device *dev,
396 struct comedi_subdevice *s)
398 devpriv->timer_running = 0;
399 del_timer(&devpriv->timer);
403 static int waveform_ai_insn_read(struct comedi_device *dev,
404 struct comedi_subdevice *s,
405 struct comedi_insn *insn, unsigned int *data)
407 int i, chan = CR_CHAN(insn->chanspec);
409 for (i = 0; i < insn->n; i++)
410 data[i] = devpriv->ao_loopbacks[chan];
415 static int waveform_ao_insn_write(struct comedi_device *dev,
416 struct comedi_subdevice *s,
417 struct comedi_insn *insn, unsigned int *data)
419 int i, chan = CR_CHAN(insn->chanspec);
421 for (i = 0; i < insn->n; i++)
422 devpriv->ao_loopbacks[chan] = data[i];
427 static int waveform_attach(struct comedi_device *dev,
428 struct comedi_devconfig *it)
430 const struct waveform_board *board = comedi_board(dev);
431 struct comedi_subdevice *s;
432 int amplitude = it->options[0];
433 int period = it->options[1];
437 dev->board_name = board->name;
439 if (alloc_private(dev, sizeof(struct waveform_private)) < 0)
442 /* set default amplitude and period */
444 amplitude = 1000000; /* 1 volt */
446 period = 100000; /* 0.1 sec */
448 devpriv->uvolt_amplitude = amplitude;
449 devpriv->usec_period = period;
451 ret = comedi_alloc_subdevices(dev, 2);
455 s = dev->subdevices + 0;
456 dev->read_subdev = s;
457 /* analog input subdevice */
458 s->type = COMEDI_SUBD_AI;
459 s->subdev_flags = SDF_READABLE | SDF_GROUND | SDF_CMD_READ;
460 s->n_chan = board->ai_chans;
461 s->maxdata = (1 << board->ai_bits) - 1;
462 s->range_table = &waveform_ai_ranges;
463 s->len_chanlist = s->n_chan * 2;
464 s->insn_read = waveform_ai_insn_read;
465 s->do_cmd = waveform_ai_cmd;
466 s->do_cmdtest = waveform_ai_cmdtest;
467 s->cancel = waveform_ai_cancel;
469 s = dev->subdevices + 1;
470 dev->write_subdev = s;
471 /* analog output subdevice (loopback) */
472 s->type = COMEDI_SUBD_AO;
473 s->subdev_flags = SDF_WRITEABLE | SDF_GROUND;
474 s->n_chan = board->ai_chans;
475 s->maxdata = (1 << board->ai_bits) - 1;
476 s->range_table = &waveform_ai_ranges;
477 s->len_chanlist = s->n_chan * 2;
478 s->insn_write = waveform_ao_insn_write;
480 s->do_cmdtest = NULL;
483 /* Our default loopback value is just a 0V flatline */
484 for (i = 0; i < s->n_chan; i++)
485 devpriv->ao_loopbacks[i] = s->maxdata / 2;
487 init_timer(&(devpriv->timer));
488 devpriv->timer.function = waveform_ai_interrupt;
489 devpriv->timer.data = (unsigned long)dev;
491 printk(KERN_INFO "comedi%d: comedi_test: "
492 "%i microvolt, %li microsecond waveform attached\n", dev->minor,
493 devpriv->uvolt_amplitude, devpriv->usec_period);
497 static void waveform_detach(struct comedi_device *dev)
500 waveform_ai_cancel(dev, dev->read_subdev);
503 static const struct waveform_board waveform_boards[] = {
505 .name = "comedi_test",
512 static struct comedi_driver waveform_driver = {
513 .driver_name = "comedi_test",
514 .module = THIS_MODULE,
515 .attach = waveform_attach,
516 .detach = waveform_detach,
517 .board_name = &waveform_boards[0].name,
518 .offset = sizeof(struct waveform_board),
519 .num_names = ARRAY_SIZE(waveform_boards),
521 module_comedi_driver(waveform_driver);
523 MODULE_AUTHOR("Comedi http://www.comedi.org");
524 MODULE_DESCRIPTION("Comedi low-level driver");
525 MODULE_LICENSE("GPL");