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 <Joachim.Wuttke@icn.siemens.de>
11 * Copyright (C) 2002 Frank Mori Hess <fmhess@users.sourceforge.net>
12 *
13 * COMEDI - Linux Control and Measurement Device Interface
14 * Copyright (C) 2000 David A. Schleef <ds@schleef.org>
15 */
16
17/*
18 * Driver: comedi_test
19 * Description: generates fake waveforms
20 * Author: Joachim Wuttke <Joachim.Wuttke@icn.siemens.de>, Frank Mori Hess
21 * <fmhess@users.sourceforge.net>, 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
60static bool config_mode;
61static unsigned int set_amplitude;
62static unsigned int set_period;
63static const struct class ctcls = {
64 .name = CLASS_NAME,
65};
66static struct device *ctdev;
67
68module_param_named(noauto, config_mode, bool, 0444);
69MODULE_PARM_DESC(noauto, "Disable auto-configuration: (1=disable [defaults to enable])");
70
71module_param_named(amplitude, set_amplitude, uint, 0444);
72MODULE_PARM_DESC(amplitude, "Set auto mode wave amplitude in microvolts: (defaults to 1 volt)");
73
74module_param_named(period, set_period, uint, 0444);
75MODULE_PARM_DESC(period, "Set auto mode wave period in microseconds: (defaults to 0.1 sec)");
76
77/* Data unique to this driver */
78struct 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 bool ai_timer_enable:1; /* should AI timer be running? */
91 bool ao_timer_enable:1; /* should AO timer be running? */
92 unsigned short ao_loopbacks[N_CHANS];
93};
94
95/* fake analog input ranges */
96static const struct comedi_lrange waveform_ai_ranges = {
97 2, {
98 BIP_RANGE(10),
99 BIP_RANGE(5)
100 }
101};
102
103static unsigned short fake_sawtooth(struct comedi_device *dev,
104 unsigned int range_index,
105 unsigned int current_time)
106{
107 struct waveform_private *devpriv = dev->private;
108 struct comedi_subdevice *s = dev->read_subdev;
109 unsigned int offset = s->maxdata / 2;
110 u64 value;
111 const struct comedi_krange *krange =
112 &s->range_table->range[range_index];
113 u64 binary_amplitude;
114
115 binary_amplitude = s->maxdata;
116 binary_amplitude *= devpriv->wf_amplitude;
117 do_div(binary_amplitude, krange->max - krange->min);
118
119 value = current_time;
120 value *= binary_amplitude * 2;
121 do_div(value, devpriv->wf_period);
122 value += offset;
123 /* get rid of sawtooth's dc offset and clamp value */
124 if (value < binary_amplitude) {
125 value = 0; /* negative saturation */
126 } else {
127 value -= binary_amplitude;
128 if (value > s->maxdata)
129 value = s->maxdata; /* positive saturation */
130 }
131
132 return value;
133}
134
135static unsigned short fake_squarewave(struct comedi_device *dev,
136 unsigned int range_index,
137 unsigned int current_time)
138{
139 struct waveform_private *devpriv = dev->private;
140 struct comedi_subdevice *s = dev->read_subdev;
141 unsigned int offset = s->maxdata / 2;
142 u64 value;
143 const struct comedi_krange *krange =
144 &s->range_table->range[range_index];
145
146 value = s->maxdata;
147 value *= devpriv->wf_amplitude;
148 do_div(value, krange->max - krange->min);
149
150 /* get one of two values for square-wave and clamp */
151 if (current_time < devpriv->wf_period / 2) {
152 if (offset < value)
153 value = 0; /* negative saturation */
154 else
155 value = offset - value;
156 } else {
157 value += offset;
158 if (value > s->maxdata)
159 value = s->maxdata; /* positive saturation */
160 }
161
162 return value;
163}
164
165static unsigned short fake_flatline(struct comedi_device *dev,
166 unsigned int range_index,
167 unsigned int current_time)
168{
169 return dev->read_subdev->maxdata / 2;
170}
171
172/* generates a different waveform depending on what channel is read */
173static unsigned short fake_waveform(struct comedi_device *dev,
174 unsigned int channel, unsigned int range,
175 unsigned int current_time)
176{
177 enum {
178 SAWTOOTH_CHAN,
179 SQUARE_CHAN,
180 };
181 switch (channel) {
182 case SAWTOOTH_CHAN:
183 return fake_sawtooth(dev, range_index: range, current_time);
184 case SQUARE_CHAN:
185 return fake_squarewave(dev, range_index: range, current_time);
186 default:
187 break;
188 }
189
190 return fake_flatline(dev, range_index: range, current_time);
191}
192
193/*
194 * This is the background routine used to generate arbitrary data.
195 * It should run in the background; therefore it is scheduled by
196 * a timer mechanism.
197 */
198static void waveform_ai_timer(struct timer_list *t)
199{
200 struct waveform_private *devpriv = from_timer(devpriv, t, ai_timer);
201 struct comedi_device *dev = devpriv->dev;
202 struct comedi_subdevice *s = dev->read_subdev;
203 struct comedi_async *async = s->async;
204 struct comedi_cmd *cmd = &async->cmd;
205 u64 now;
206 unsigned int nsamples;
207 unsigned int time_increment;
208
209 now = ktime_to_us(kt: ktime_get());
210 nsamples = comedi_nsamples_left(s, UINT_MAX);
211
212 while (nsamples && devpriv->ai_convert_time < now) {
213 unsigned int chanspec = cmd->chanlist[async->cur_chan];
214 unsigned short sample;
215
216 sample = fake_waveform(dev, CR_CHAN(chanspec),
217 CR_RANGE(chanspec), current_time: devpriv->wf_current);
218 if (comedi_buf_write_samples(s, data: &sample, nsamples: 1) == 0)
219 goto overrun;
220 time_increment = devpriv->ai_convert_period;
221 if (async->scan_progress == 0) {
222 /* done last conversion in scan, so add dead time */
223 time_increment += devpriv->ai_scan_period -
224 devpriv->ai_convert_period *
225 cmd->scan_end_arg;
226 }
227 devpriv->wf_current += time_increment;
228 if (devpriv->wf_current >= devpriv->wf_period)
229 devpriv->wf_current %= devpriv->wf_period;
230 devpriv->ai_convert_time += time_increment;
231 nsamples--;
232 }
233
234 if (cmd->stop_src == TRIG_COUNT && async->scans_done >= cmd->stop_arg) {
235 async->events |= COMEDI_CB_EOA;
236 } else {
237 if (devpriv->ai_convert_time > now)
238 time_increment = devpriv->ai_convert_time - now;
239 else
240 time_increment = 1;
241 spin_lock(lock: &dev->spinlock);
242 if (devpriv->ai_timer_enable) {
243 mod_timer(timer: &devpriv->ai_timer,
244 expires: jiffies + usecs_to_jiffies(u: time_increment));
245 }
246 spin_unlock(lock: &dev->spinlock);
247 }
248
249overrun:
250 comedi_handle_events(dev, s);
251}
252
253static int waveform_ai_cmdtest(struct comedi_device *dev,
254 struct comedi_subdevice *s,
255 struct comedi_cmd *cmd)
256{
257 int err = 0;
258 unsigned int arg, limit;
259
260 /* Step 1 : check if triggers are trivially valid */
261
262 err |= comedi_check_trigger_src(src: &cmd->start_src, TRIG_NOW);
263 err |= comedi_check_trigger_src(src: &cmd->scan_begin_src,
264 TRIG_FOLLOW | TRIG_TIMER);
265 err |= comedi_check_trigger_src(src: &cmd->convert_src,
266 TRIG_NOW | TRIG_TIMER);
267 err |= comedi_check_trigger_src(src: &cmd->scan_end_src, TRIG_COUNT);
268 err |= comedi_check_trigger_src(src: &cmd->stop_src, TRIG_COUNT | TRIG_NONE);
269
270 if (err)
271 return 1;
272
273 /* Step 2a : make sure trigger sources are unique */
274
275 err |= comedi_check_trigger_is_unique(src: cmd->convert_src);
276 err |= comedi_check_trigger_is_unique(src: cmd->stop_src);
277
278 /* Step 2b : and mutually compatible */
279
280 if (cmd->scan_begin_src == TRIG_FOLLOW && cmd->convert_src == TRIG_NOW)
281 err |= -EINVAL; /* scan period would be 0 */
282
283 if (err)
284 return 2;
285
286 /* Step 3: check if arguments are trivially valid */
287
288 err |= comedi_check_trigger_arg_is(arg: &cmd->start_arg, val: 0);
289
290 if (cmd->convert_src == TRIG_NOW) {
291 err |= comedi_check_trigger_arg_is(arg: &cmd->convert_arg, val: 0);
292 } else { /* cmd->convert_src == TRIG_TIMER */
293 if (cmd->scan_begin_src == TRIG_FOLLOW) {
294 err |= comedi_check_trigger_arg_min(arg: &cmd->convert_arg,
295 NSEC_PER_USEC);
296 }
297 }
298
299 if (cmd->scan_begin_src == TRIG_FOLLOW) {
300 err |= comedi_check_trigger_arg_is(arg: &cmd->scan_begin_arg, val: 0);
301 } else { /* cmd->scan_begin_src == TRIG_TIMER */
302 err |= comedi_check_trigger_arg_min(arg: &cmd->scan_begin_arg,
303 NSEC_PER_USEC);
304 }
305
306 err |= comedi_check_trigger_arg_min(arg: &cmd->chanlist_len, val: 1);
307 err |= comedi_check_trigger_arg_is(arg: &cmd->scan_end_arg,
308 val: cmd->chanlist_len);
309
310 if (cmd->stop_src == TRIG_COUNT)
311 err |= comedi_check_trigger_arg_min(arg: &cmd->stop_arg, val: 1);
312 else /* cmd->stop_src == TRIG_NONE */
313 err |= comedi_check_trigger_arg_is(arg: &cmd->stop_arg, val: 0);
314
315 if (err)
316 return 3;
317
318 /* step 4: fix up any arguments */
319
320 if (cmd->convert_src == TRIG_TIMER) {
321 /* round convert_arg to nearest microsecond */
322 arg = cmd->convert_arg;
323 arg = min(arg,
324 rounddown(UINT_MAX, (unsigned int)NSEC_PER_USEC));
325 arg = NSEC_PER_USEC * DIV_ROUND_CLOSEST(arg, NSEC_PER_USEC);
326 if (cmd->scan_begin_arg == TRIG_TIMER) {
327 /* limit convert_arg to keep scan_begin_arg in range */
328 limit = UINT_MAX / cmd->scan_end_arg;
329 limit = rounddown(limit, (unsigned int)NSEC_PER_SEC);
330 arg = min(arg, limit);
331 }
332 err |= comedi_check_trigger_arg_is(arg: &cmd->convert_arg, val: arg);
333 }
334
335 if (cmd->scan_begin_src == TRIG_TIMER) {
336 /* round scan_begin_arg to nearest microsecond */
337 arg = cmd->scan_begin_arg;
338 arg = min(arg,
339 rounddown(UINT_MAX, (unsigned int)NSEC_PER_USEC));
340 arg = NSEC_PER_USEC * DIV_ROUND_CLOSEST(arg, NSEC_PER_USEC);
341 if (cmd->convert_src == TRIG_TIMER) {
342 /* but ensure scan_begin_arg is large enough */
343 arg = max(arg, cmd->convert_arg * cmd->scan_end_arg);
344 }
345 err |= comedi_check_trigger_arg_is(arg: &cmd->scan_begin_arg, val: arg);
346 }
347
348 if (err)
349 return 4;
350
351 return 0;
352}
353
354static int waveform_ai_cmd(struct comedi_device *dev,
355 struct comedi_subdevice *s)
356{
357 struct waveform_private *devpriv = dev->private;
358 struct comedi_cmd *cmd = &s->async->cmd;
359 unsigned int first_convert_time;
360 u64 wf_current;
361
362 if (cmd->flags & CMDF_PRIORITY) {
363 dev_err(dev->class_dev,
364 "commands at RT priority not supported in this driver\n");
365 return -1;
366 }
367
368 if (cmd->convert_src == TRIG_NOW)
369 devpriv->ai_convert_period = 0;
370 else /* cmd->convert_src == TRIG_TIMER */
371 devpriv->ai_convert_period = cmd->convert_arg / NSEC_PER_USEC;
372
373 if (cmd->scan_begin_src == TRIG_FOLLOW) {
374 devpriv->ai_scan_period = devpriv->ai_convert_period *
375 cmd->scan_end_arg;
376 } else { /* cmd->scan_begin_src == TRIG_TIMER */
377 devpriv->ai_scan_period = cmd->scan_begin_arg / NSEC_PER_USEC;
378 }
379
380 /*
381 * Simulate first conversion to occur at convert period after
382 * conversion timer starts. If scan_begin_src is TRIG_FOLLOW, assume
383 * the conversion timer starts immediately. If scan_begin_src is
384 * TRIG_TIMER, assume the conversion timer starts after the scan
385 * period.
386 */
387 first_convert_time = devpriv->ai_convert_period;
388 if (cmd->scan_begin_src == TRIG_TIMER)
389 first_convert_time += devpriv->ai_scan_period;
390 devpriv->ai_convert_time = ktime_to_us(kt: ktime_get()) +
391 first_convert_time;
392
393 /* Determine time within waveform period at time of conversion. */
394 wf_current = devpriv->ai_convert_time;
395 devpriv->wf_current = do_div(wf_current, devpriv->wf_period);
396
397 /*
398 * Schedule timer to expire just after first conversion time.
399 * Seem to need an extra jiffy here, otherwise timer expires slightly
400 * early!
401 */
402 spin_lock_bh(lock: &dev->spinlock);
403 devpriv->ai_timer_enable = true;
404 devpriv->ai_timer.expires =
405 jiffies + usecs_to_jiffies(u: devpriv->ai_convert_period) + 1;
406 add_timer(timer: &devpriv->ai_timer);
407 spin_unlock_bh(lock: &dev->spinlock);
408 return 0;
409}
410
411static int waveform_ai_cancel(struct comedi_device *dev,
412 struct comedi_subdevice *s)
413{
414 struct waveform_private *devpriv = dev->private;
415
416 spin_lock_bh(lock: &dev->spinlock);
417 devpriv->ai_timer_enable = false;
418 spin_unlock_bh(lock: &dev->spinlock);
419 if (in_softirq()) {
420 /* Assume we were called from the timer routine itself. */
421 del_timer(timer: &devpriv->ai_timer);
422 } else {
423 del_timer_sync(timer: &devpriv->ai_timer);
424 }
425 return 0;
426}
427
428static int waveform_ai_insn_read(struct comedi_device *dev,
429 struct comedi_subdevice *s,
430 struct comedi_insn *insn, unsigned int *data)
431{
432 struct waveform_private *devpriv = dev->private;
433 int i, chan = CR_CHAN(insn->chanspec);
434
435 for (i = 0; i < insn->n; i++)
436 data[i] = devpriv->ao_loopbacks[chan];
437
438 return insn->n;
439}
440
441/*
442 * This is the background routine to handle AO commands, scheduled by
443 * a timer mechanism.
444 */
445static void waveform_ao_timer(struct timer_list *t)
446{
447 struct waveform_private *devpriv = from_timer(devpriv, t, ao_timer);
448 struct comedi_device *dev = devpriv->dev;
449 struct comedi_subdevice *s = dev->write_subdev;
450 struct comedi_async *async = s->async;
451 struct comedi_cmd *cmd = &async->cmd;
452 u64 now;
453 u64 scans_since;
454 unsigned int scans_avail = 0;
455
456 /* determine number of scan periods since last time */
457 now = ktime_to_us(kt: ktime_get());
458 scans_since = now - devpriv->ao_last_scan_time;
459 do_div(scans_since, devpriv->ao_scan_period);
460 if (scans_since) {
461 unsigned int i;
462
463 /* determine scans in buffer, limit to scans to do this time */
464 scans_avail = comedi_nscans_left(s, nscans: 0);
465 if (scans_avail > scans_since)
466 scans_avail = scans_since;
467 if (scans_avail) {
468 /* skip all but the last scan to save processing time */
469 if (scans_avail > 1) {
470 unsigned int skip_bytes, nbytes;
471
472 skip_bytes =
473 comedi_samples_to_bytes(s, nsamples: cmd->scan_end_arg *
474 (scans_avail - 1));
475 nbytes = comedi_buf_read_alloc(s, n: skip_bytes);
476 comedi_buf_read_free(s, n: nbytes);
477 comedi_inc_scan_progress(s, num_bytes: nbytes);
478 if (nbytes < skip_bytes) {
479 /* unexpected underrun! (cancelled?) */
480 async->events |= COMEDI_CB_OVERFLOW;
481 goto underrun;
482 }
483 }
484 /* output the last scan */
485 for (i = 0; i < cmd->scan_end_arg; i++) {
486 unsigned int chan = CR_CHAN(cmd->chanlist[i]);
487 unsigned short *pd;
488
489 pd = &devpriv->ao_loopbacks[chan];
490
491 if (!comedi_buf_read_samples(s, data: pd, nsamples: 1)) {
492 /* unexpected underrun! (cancelled?) */
493 async->events |= COMEDI_CB_OVERFLOW;
494 goto underrun;
495 }
496 }
497 /* advance time of last scan */
498 devpriv->ao_last_scan_time +=
499 (u64)scans_avail * devpriv->ao_scan_period;
500 }
501 }
502 if (cmd->stop_src == TRIG_COUNT && async->scans_done >= cmd->stop_arg) {
503 async->events |= COMEDI_CB_EOA;
504 } else if (scans_avail < scans_since) {
505 async->events |= COMEDI_CB_OVERFLOW;
506 } else {
507 unsigned int time_inc = devpriv->ao_last_scan_time +
508 devpriv->ao_scan_period - now;
509
510 spin_lock(lock: &dev->spinlock);
511 if (devpriv->ao_timer_enable) {
512 mod_timer(timer: &devpriv->ao_timer,
513 expires: jiffies + usecs_to_jiffies(u: time_inc));
514 }
515 spin_unlock(lock: &dev->spinlock);
516 }
517
518underrun:
519 comedi_handle_events(dev, s);
520}
521
522static int waveform_ao_inttrig_start(struct comedi_device *dev,
523 struct comedi_subdevice *s,
524 unsigned int trig_num)
525{
526 struct waveform_private *devpriv = dev->private;
527 struct comedi_async *async = s->async;
528 struct comedi_cmd *cmd = &async->cmd;
529
530 if (trig_num != cmd->start_arg)
531 return -EINVAL;
532
533 async->inttrig = NULL;
534
535 devpriv->ao_last_scan_time = ktime_to_us(kt: ktime_get());
536 spin_lock_bh(lock: &dev->spinlock);
537 devpriv->ao_timer_enable = true;
538 devpriv->ao_timer.expires =
539 jiffies + usecs_to_jiffies(u: devpriv->ao_scan_period);
540 add_timer(timer: &devpriv->ao_timer);
541 spin_unlock_bh(lock: &dev->spinlock);
542
543 return 1;
544}
545
546static int waveform_ao_cmdtest(struct comedi_device *dev,
547 struct comedi_subdevice *s,
548 struct comedi_cmd *cmd)
549{
550 int err = 0;
551 unsigned int arg;
552
553 /* Step 1 : check if triggers are trivially valid */
554
555 err |= comedi_check_trigger_src(src: &cmd->start_src, TRIG_INT);
556 err |= comedi_check_trigger_src(src: &cmd->scan_begin_src, TRIG_TIMER);
557 err |= comedi_check_trigger_src(src: &cmd->convert_src, TRIG_NOW);
558 err |= comedi_check_trigger_src(src: &cmd->scan_end_src, TRIG_COUNT);
559 err |= comedi_check_trigger_src(src: &cmd->stop_src, TRIG_COUNT | TRIG_NONE);
560
561 if (err)
562 return 1;
563
564 /* Step 2a : make sure trigger sources are unique */
565
566 err |= comedi_check_trigger_is_unique(src: cmd->stop_src);
567
568 /* Step 2b : and mutually compatible */
569
570 if (err)
571 return 2;
572
573 /* Step 3: check if arguments are trivially valid */
574
575 err |= comedi_check_trigger_arg_min(arg: &cmd->scan_begin_arg,
576 NSEC_PER_USEC);
577 err |= comedi_check_trigger_arg_is(arg: &cmd->convert_arg, val: 0);
578 err |= comedi_check_trigger_arg_min(arg: &cmd->chanlist_len, val: 1);
579 err |= comedi_check_trigger_arg_is(arg: &cmd->scan_end_arg,
580 val: cmd->chanlist_len);
581 if (cmd->stop_src == TRIG_COUNT)
582 err |= comedi_check_trigger_arg_min(arg: &cmd->stop_arg, val: 1);
583 else /* cmd->stop_src == TRIG_NONE */
584 err |= comedi_check_trigger_arg_is(arg: &cmd->stop_arg, val: 0);
585
586 if (err)
587 return 3;
588
589 /* step 4: fix up any arguments */
590
591 /* round scan_begin_arg to nearest microsecond */
592 arg = cmd->scan_begin_arg;
593 arg = min(arg, rounddown(UINT_MAX, (unsigned int)NSEC_PER_USEC));
594 arg = NSEC_PER_USEC * DIV_ROUND_CLOSEST(arg, NSEC_PER_USEC);
595 err |= comedi_check_trigger_arg_is(arg: &cmd->scan_begin_arg, val: arg);
596
597 if (err)
598 return 4;
599
600 return 0;
601}
602
603static int waveform_ao_cmd(struct comedi_device *dev,
604 struct comedi_subdevice *s)
605{
606 struct waveform_private *devpriv = dev->private;
607 struct comedi_cmd *cmd = &s->async->cmd;
608
609 if (cmd->flags & CMDF_PRIORITY) {
610 dev_err(dev->class_dev,
611 "commands at RT priority not supported in this driver\n");
612 return -1;
613 }
614
615 devpriv->ao_scan_period = cmd->scan_begin_arg / NSEC_PER_USEC;
616 s->async->inttrig = waveform_ao_inttrig_start;
617 return 0;
618}
619
620static int waveform_ao_cancel(struct comedi_device *dev,
621 struct comedi_subdevice *s)
622{
623 struct waveform_private *devpriv = dev->private;
624
625 s->async->inttrig = NULL;
626 spin_lock_bh(lock: &dev->spinlock);
627 devpriv->ao_timer_enable = false;
628 spin_unlock_bh(lock: &dev->spinlock);
629 if (in_softirq()) {
630 /* Assume we were called from the timer routine itself. */
631 del_timer(timer: &devpriv->ao_timer);
632 } else {
633 del_timer_sync(timer: &devpriv->ao_timer);
634 }
635 return 0;
636}
637
638static int waveform_ao_insn_write(struct comedi_device *dev,
639 struct comedi_subdevice *s,
640 struct comedi_insn *insn, unsigned int *data)
641{
642 struct waveform_private *devpriv = dev->private;
643 int i, chan = CR_CHAN(insn->chanspec);
644
645 for (i = 0; i < insn->n; i++)
646 devpriv->ao_loopbacks[chan] = data[i];
647
648 return insn->n;
649}
650
651static int waveform_ai_insn_config(struct comedi_device *dev,
652 struct comedi_subdevice *s,
653 struct comedi_insn *insn,
654 unsigned int *data)
655{
656 if (data[0] == INSN_CONFIG_GET_CMD_TIMING_CONSTRAINTS) {
657 /*
658 * input: data[1], data[2] : scan_begin_src, convert_src
659 * output: data[1], data[2] : scan_begin_min, convert_min
660 */
661 if (data[1] == TRIG_FOLLOW) {
662 /* exactly TRIG_FOLLOW case */
663 data[1] = 0;
664 data[2] = NSEC_PER_USEC;
665 } else {
666 data[1] = NSEC_PER_USEC;
667 if (data[2] & TRIG_TIMER)
668 data[2] = NSEC_PER_USEC;
669 else
670 data[2] = 0;
671 }
672 return 0;
673 }
674
675 return -EINVAL;
676}
677
678static int waveform_ao_insn_config(struct comedi_device *dev,
679 struct comedi_subdevice *s,
680 struct comedi_insn *insn,
681 unsigned int *data)
682{
683 if (data[0] == INSN_CONFIG_GET_CMD_TIMING_CONSTRAINTS) {
684 /* we don't care about actual channels */
685 data[1] = NSEC_PER_USEC; /* scan_begin_min */
686 data[2] = 0; /* convert_min */
687 return 0;
688 }
689
690 return -EINVAL;
691}
692
693static int waveform_common_attach(struct comedi_device *dev,
694 int amplitude, int period)
695{
696 struct waveform_private *devpriv;
697 struct comedi_subdevice *s;
698 int i;
699 int ret;
700
701 devpriv = comedi_alloc_devpriv(dev, size: sizeof(*devpriv));
702 if (!devpriv)
703 return -ENOMEM;
704
705 devpriv->wf_amplitude = amplitude;
706 devpriv->wf_period = period;
707
708 ret = comedi_alloc_subdevices(dev, num_subdevices: 2);
709 if (ret)
710 return ret;
711
712 s = &dev->subdevices[0];
713 dev->read_subdev = s;
714 /* analog input subdevice */
715 s->type = COMEDI_SUBD_AI;
716 s->subdev_flags = SDF_READABLE | SDF_GROUND | SDF_CMD_READ;
717 s->n_chan = N_CHANS;
718 s->maxdata = 0xffff;
719 s->range_table = &waveform_ai_ranges;
720 s->len_chanlist = s->n_chan * 2;
721 s->insn_read = waveform_ai_insn_read;
722 s->do_cmd = waveform_ai_cmd;
723 s->do_cmdtest = waveform_ai_cmdtest;
724 s->cancel = waveform_ai_cancel;
725 s->insn_config = waveform_ai_insn_config;
726
727 s = &dev->subdevices[1];
728 dev->write_subdev = s;
729 /* analog output subdevice (loopback) */
730 s->type = COMEDI_SUBD_AO;
731 s->subdev_flags = SDF_WRITABLE | SDF_GROUND | SDF_CMD_WRITE;
732 s->n_chan = N_CHANS;
733 s->maxdata = 0xffff;
734 s->range_table = &waveform_ai_ranges;
735 s->len_chanlist = s->n_chan;
736 s->insn_write = waveform_ao_insn_write;
737 s->insn_read = waveform_ai_insn_read; /* do same as AI insn_read */
738 s->do_cmd = waveform_ao_cmd;
739 s->do_cmdtest = waveform_ao_cmdtest;
740 s->cancel = waveform_ao_cancel;
741 s->insn_config = waveform_ao_insn_config;
742
743 /* Our default loopback value is just a 0V flatline */
744 for (i = 0; i < s->n_chan; i++)
745 devpriv->ao_loopbacks[i] = s->maxdata / 2;
746
747 devpriv->dev = dev;
748 timer_setup(&devpriv->ai_timer, waveform_ai_timer, 0);
749 timer_setup(&devpriv->ao_timer, waveform_ao_timer, 0);
750
751 dev_info(dev->class_dev,
752 "%s: %u microvolt, %u microsecond waveform attached\n",
753 dev->board_name,
754 devpriv->wf_amplitude, devpriv->wf_period);
755
756 return 0;
757}
758
759static int waveform_attach(struct comedi_device *dev,
760 struct comedi_devconfig *it)
761{
762 int amplitude = it->options[0];
763 int period = it->options[1];
764
765 /* set default amplitude and period */
766 if (amplitude <= 0)
767 amplitude = 1000000; /* 1 volt */
768 if (period <= 0)
769 period = 100000; /* 0.1 sec */
770
771 return waveform_common_attach(dev, amplitude, period);
772}
773
774static int waveform_auto_attach(struct comedi_device *dev,
775 unsigned long context_unused)
776{
777 int amplitude = set_amplitude;
778 int period = set_period;
779
780 /* set default amplitude and period */
781 if (!amplitude)
782 amplitude = 1000000; /* 1 volt */
783 if (!period)
784 period = 100000; /* 0.1 sec */
785
786 return waveform_common_attach(dev, amplitude, period);
787}
788
789static void waveform_detach(struct comedi_device *dev)
790{
791 struct waveform_private *devpriv = dev->private;
792
793 if (devpriv) {
794 del_timer_sync(timer: &devpriv->ai_timer);
795 del_timer_sync(timer: &devpriv->ao_timer);
796 }
797}
798
799static struct comedi_driver waveform_driver = {
800 .driver_name = "comedi_test",
801 .module = THIS_MODULE,
802 .attach = waveform_attach,
803 .auto_attach = waveform_auto_attach,
804 .detach = waveform_detach,
805};
806
807/*
808 * For auto-configuration, a device is created to stand in for a
809 * real hardware device.
810 */
811static int __init comedi_test_init(void)
812{
813 int ret;
814
815 ret = comedi_driver_register(driver: &waveform_driver);
816 if (ret) {
817 pr_err("comedi_test: unable to register driver\n");
818 return ret;
819 }
820
821 if (!config_mode) {
822 ret = class_register(class: &ctcls);
823 if (ret) {
824 pr_warn("comedi_test: unable to create class\n");
825 goto clean3;
826 }
827
828 ctdev = device_create(cls: &ctcls, NULL, MKDEV(0, 0), NULL, DEV_NAME);
829 if (IS_ERR(ptr: ctdev)) {
830 pr_warn("comedi_test: unable to create device\n");
831 goto clean2;
832 }
833
834 ret = comedi_auto_config(hardware_device: ctdev, driver: &waveform_driver, context: 0);
835 if (ret) {
836 pr_warn("comedi_test: unable to auto-configure device\n");
837 goto clean;
838 }
839 }
840
841 return 0;
842
843clean:
844 device_destroy(cls: &ctcls, MKDEV(0, 0));
845clean2:
846 class_unregister(class: &ctcls);
847clean3:
848 return 0;
849}
850module_init(comedi_test_init);
851
852static void __exit comedi_test_exit(void)
853{
854 if (ctdev)
855 comedi_auto_unconfig(hardware_device: ctdev);
856
857 if (class_is_registered(class: &ctcls)) {
858 device_destroy(cls: &ctcls, MKDEV(0, 0));
859 class_unregister(class: &ctcls);
860 }
861
862 comedi_driver_unregister(driver: &waveform_driver);
863}
864module_exit(comedi_test_exit);
865
866MODULE_AUTHOR("Comedi https://www.comedi.org");
867MODULE_DESCRIPTION("Comedi low-level driver");
868MODULE_LICENSE("GPL");
869

source code of linux/drivers/comedi/drivers/comedi_test.c