1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Comedi driver for Data Translation DT2811
4 *
5 * COMEDI - Linux Control and Measurement Device Interface
6 * Copyright (C) David A. Schleef <ds@schleef.org>
7 */
8
9/*
10 * Driver: dt2811
11 * Description: Data Translation DT2811
12 * Author: ds
13 * Devices: [Data Translation] DT2811-PGL (dt2811-pgl), DT2811-PGH (dt2811-pgh)
14 * Status: works
15 *
16 * Configuration options:
17 * [0] - I/O port base address
18 * [1] - IRQ (optional, needed for async command support)
19 * [2] - A/D reference (# of analog inputs)
20 * 0 = single-ended (16 channels)
21 * 1 = differential (8 channels)
22 * 2 = pseudo-differential (16 channels)
23 * [3] - A/D range (deprecated, see below)
24 * [4] - D/A 0 range (deprecated, see below)
25 * [5] - D/A 1 range (deprecated, see below)
26 *
27 * Notes:
28 * - A/D ranges are not programmable but the gain is. The AI subdevice has
29 * a range_table containing all the possible analog input range/gain
30 * options for the dt2811-pgh or dt2811-pgl. Use the range that matches
31 * your board configuration and the desired gain to correctly convert
32 * between data values and physical units and to set the correct output
33 * gain.
34 * - D/A ranges are not programmable. The AO subdevice has a range_table
35 * containing all the possible analog output ranges. Use the range
36 * that matches your board configuration to convert between data
37 * values and physical units.
38 */
39
40#include <linux/module.h>
41#include <linux/interrupt.h>
42#include <linux/delay.h>
43#include <linux/comedi/comedidev.h>
44
45/*
46 * Register I/O map
47 */
48#define DT2811_ADCSR_REG 0x00 /* r/w A/D Control/Status */
49#define DT2811_ADCSR_ADDONE BIT(7) /* r 1=A/D conv done */
50#define DT2811_ADCSR_ADERROR BIT(6) /* r 1=A/D error */
51#define DT2811_ADCSR_ADBUSY BIT(5) /* r 1=A/D busy */
52#define DT2811_ADCSR_CLRERROR BIT(4)
53#define DT2811_ADCSR_DMAENB BIT(3) /* r/w 1=dma ena */
54#define DT2811_ADCSR_INTENB BIT(2) /* r/w 1=interrupts ena */
55#define DT2811_ADCSR_ADMODE(x) (((x) & 0x3) << 0)
56
57#define DT2811_ADGCR_REG 0x01 /* r/w A/D Gain/Channel */
58#define DT2811_ADGCR_GAIN(x) (((x) & 0x3) << 6)
59#define DT2811_ADGCR_CHAN(x) (((x) & 0xf) << 0)
60
61#define DT2811_ADDATA_LO_REG 0x02 /* r A/D Data low byte */
62#define DT2811_ADDATA_HI_REG 0x03 /* r A/D Data high byte */
63
64#define DT2811_DADATA_LO_REG(x) (0x02 + ((x) * 2)) /* w D/A Data low */
65#define DT2811_DADATA_HI_REG(x) (0x03 + ((x) * 2)) /* w D/A Data high */
66
67#define DT2811_DI_REG 0x06 /* r Digital Input Port 0 */
68#define DT2811_DO_REG 0x06 /* w Digital Output Port 1 */
69
70#define DT2811_TMRCTR_REG 0x07 /* r/w Timer/Counter */
71#define DT2811_TMRCTR_MANTISSA(x) (((x) & 0x7) << 3)
72#define DT2811_TMRCTR_EXPONENT(x) (((x) & 0x7) << 0)
73
74#define DT2811_OSC_BASE 1666 /* 600 kHz = 1666.6667ns */
75
76/*
77 * Timer frequency control:
78 * DT2811_TMRCTR_MANTISSA DT2811_TMRCTR_EXPONENT
79 * val divisor frequency val multiply divisor/divide frequency by
80 * 0 1 600 kHz 0 1
81 * 1 10 60 kHz 1 10
82 * 2 2 300 kHz 2 100
83 * 3 3 200 kHz 3 1000
84 * 4 4 150 kHz 4 10000
85 * 5 5 120 kHz 5 100000
86 * 6 6 100 kHz 6 1000000
87 * 7 12 50 kHz 7 10000000
88 */
89static const unsigned int dt2811_clk_dividers[] = {
90 1, 10, 2, 3, 4, 5, 6, 12
91};
92
93static const unsigned int dt2811_clk_multipliers[] = {
94 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000
95};
96
97/*
98 * The Analog Input range is set using jumpers on the board.
99 *
100 * Input Range W9 W10
101 * -5V to +5V In Out
102 * -2.5V to +2.5V In In
103 * 0V to +5V Out In
104 *
105 * The gain may be set to 1, 2, 4, or 8 (on the dt2811-pgh) or to
106 * 1, 10, 100, 500 (on the dt2811-pgl).
107 */
108static const struct comedi_lrange dt2811_pgh_ai_ranges = {
109 12, {
110 BIP_RANGE(5), /* range 0: gain=1 */
111 BIP_RANGE(2.5), /* range 1: gain=2 */
112 BIP_RANGE(1.25), /* range 2: gain=4 */
113 BIP_RANGE(0.625), /* range 3: gain=8 */
114
115 BIP_RANGE(2.5), /* range 0+4: gain=1 */
116 BIP_RANGE(1.25), /* range 1+4: gain=2 */
117 BIP_RANGE(0.625), /* range 2+4: gain=4 */
118 BIP_RANGE(0.3125), /* range 3+4: gain=8 */
119
120 UNI_RANGE(5), /* range 0+8: gain=1 */
121 UNI_RANGE(2.5), /* range 1+8: gain=2 */
122 UNI_RANGE(1.25), /* range 2+8: gain=4 */
123 UNI_RANGE(0.625) /* range 3+8: gain=8 */
124 }
125};
126
127static const struct comedi_lrange dt2811_pgl_ai_ranges = {
128 12, {
129 BIP_RANGE(5), /* range 0: gain=1 */
130 BIP_RANGE(0.5), /* range 1: gain=10 */
131 BIP_RANGE(0.05), /* range 2: gain=100 */
132 BIP_RANGE(0.01), /* range 3: gain=500 */
133
134 BIP_RANGE(2.5), /* range 0+4: gain=1 */
135 BIP_RANGE(0.25), /* range 1+4: gain=10 */
136 BIP_RANGE(0.025), /* range 2+4: gain=100 */
137 BIP_RANGE(0.005), /* range 3+4: gain=500 */
138
139 UNI_RANGE(5), /* range 0+8: gain=1 */
140 UNI_RANGE(0.5), /* range 1+8: gain=10 */
141 UNI_RANGE(0.05), /* range 2+8: gain=100 */
142 UNI_RANGE(0.01) /* range 3+8: gain=500 */
143 }
144};
145
146/*
147 * The Analog Output range is set per-channel using jumpers on the board.
148 *
149 * DAC0 Jumpers DAC1 Jumpers
150 * Output Range W5 W6 W7 W8 W1 W2 W3 W4
151 * -5V to +5V In Out In Out In Out In Out
152 * -2.5V to +2.5V In Out Out In In Out Out In
153 * 0 to +5V Out In Out In Out In Out In
154 */
155static const struct comedi_lrange dt2811_ao_ranges = {
156 3, {
157 BIP_RANGE(5), /* default setting from factory */
158 BIP_RANGE(2.5),
159 UNI_RANGE(5)
160 }
161};
162
163struct dt2811_board {
164 const char *name;
165 unsigned int is_pgh:1;
166};
167
168static const struct dt2811_board dt2811_boards[] = {
169 {
170 .name = "dt2811-pgh",
171 .is_pgh = 1,
172 }, {
173 .name = "dt2811-pgl",
174 },
175};
176
177struct dt2811_private {
178 unsigned int ai_divisor;
179};
180
181static unsigned int dt2811_ai_read_sample(struct comedi_device *dev,
182 struct comedi_subdevice *s)
183{
184 unsigned int val;
185
186 val = inb(port: dev->iobase + DT2811_ADDATA_LO_REG) |
187 (inb(port: dev->iobase + DT2811_ADDATA_HI_REG) << 8);
188
189 return val & s->maxdata;
190}
191
192static irqreturn_t dt2811_interrupt(int irq, void *d)
193{
194 struct comedi_device *dev = d;
195 struct comedi_subdevice *s = dev->read_subdev;
196 struct comedi_async *async = s->async;
197 struct comedi_cmd *cmd = &async->cmd;
198 unsigned int status;
199
200 if (!dev->attached)
201 return IRQ_NONE;
202
203 status = inb(port: dev->iobase + DT2811_ADCSR_REG);
204
205 if (status & DT2811_ADCSR_ADERROR) {
206 async->events |= COMEDI_CB_OVERFLOW;
207
208 outb(value: status | DT2811_ADCSR_CLRERROR,
209 port: dev->iobase + DT2811_ADCSR_REG);
210 }
211
212 if (status & DT2811_ADCSR_ADDONE) {
213 unsigned short val;
214
215 val = dt2811_ai_read_sample(dev, s);
216 comedi_buf_write_samples(s, data: &val, nsamples: 1);
217 }
218
219 if (cmd->stop_src == TRIG_COUNT && async->scans_done >= cmd->stop_arg)
220 async->events |= COMEDI_CB_EOA;
221
222 comedi_handle_events(dev, s);
223
224 return IRQ_HANDLED;
225}
226
227static int dt2811_ai_cancel(struct comedi_device *dev,
228 struct comedi_subdevice *s)
229{
230 /*
231 * Mode 0
232 * Single conversion
233 *
234 * Loading a chanspec will trigger a conversion.
235 */
236 outb(DT2811_ADCSR_ADMODE(0), port: dev->iobase + DT2811_ADCSR_REG);
237
238 return 0;
239}
240
241static void dt2811_ai_set_chanspec(struct comedi_device *dev,
242 unsigned int chanspec)
243{
244 unsigned int chan = CR_CHAN(chanspec);
245 unsigned int range = CR_RANGE(chanspec);
246
247 outb(DT2811_ADGCR_CHAN(chan) | DT2811_ADGCR_GAIN(range),
248 port: dev->iobase + DT2811_ADGCR_REG);
249}
250
251static int dt2811_ai_cmd(struct comedi_device *dev,
252 struct comedi_subdevice *s)
253{
254 struct dt2811_private *devpriv = dev->private;
255 struct comedi_cmd *cmd = &s->async->cmd;
256 unsigned int mode;
257
258 if (cmd->start_src == TRIG_NOW) {
259 /*
260 * Mode 1
261 * Continuous conversion, internal trigger and clock
262 *
263 * This resets the trigger flip-flop, disabling A/D strobes.
264 * The timer/counter register is loaded with the division
265 * ratio which will give the required sample rate.
266 *
267 * Loading the first chanspec sets the trigger flip-flop,
268 * enabling the timer/counter. A/D strobes are then generated
269 * at the rate set by the internal clock/divider.
270 */
271 mode = DT2811_ADCSR_ADMODE(1);
272 } else { /* TRIG_EXT */
273 if (cmd->convert_src == TRIG_TIMER) {
274 /*
275 * Mode 2
276 * Continuous conversion, external trigger
277 *
278 * Similar to Mode 1, with the exception that the
279 * trigger flip-flop must be set by a negative edge
280 * on the external trigger input.
281 */
282 mode = DT2811_ADCSR_ADMODE(2);
283 } else { /* TRIG_EXT */
284 /*
285 * Mode 3
286 * Continuous conversion, external trigger, clock
287 *
288 * Similar to Mode 2, with the exception that the
289 * conversion rate is set by the frequency on the
290 * external clock/divider.
291 */
292 mode = DT2811_ADCSR_ADMODE(3);
293 }
294 }
295 outb(value: mode | DT2811_ADCSR_INTENB, port: dev->iobase + DT2811_ADCSR_REG);
296
297 /* load timer */
298 outb(value: devpriv->ai_divisor, port: dev->iobase + DT2811_TMRCTR_REG);
299
300 /* load chanspec - enables timer */
301 dt2811_ai_set_chanspec(dev, chanspec: cmd->chanlist[0]);
302
303 return 0;
304}
305
306static unsigned int dt2811_ns_to_timer(unsigned int *nanosec,
307 unsigned int flags)
308{
309 unsigned long long ns;
310 unsigned int ns_lo = COMEDI_MIN_SPEED;
311 unsigned int ns_hi = 0;
312 unsigned int divisor_hi = 0;
313 unsigned int divisor_lo = 0;
314 unsigned int _div;
315 unsigned int _mult;
316
317 /*
318 * Work through all the divider/multiplier values to find the two
319 * closest divisors to generate the requested nanosecond timing.
320 */
321 for (_div = 0; _div <= 7; _div++) {
322 for (_mult = 0; _mult <= 7; _mult++) {
323 unsigned int div = dt2811_clk_dividers[_div];
324 unsigned int mult = dt2811_clk_multipliers[_mult];
325 unsigned long long divider = div * mult;
326 unsigned int divisor = DT2811_TMRCTR_MANTISSA(_div) |
327 DT2811_TMRCTR_EXPONENT(_mult);
328
329 /*
330 * The timer can be configured to run at a slowest
331 * speed of 0.005hz (600 Khz/120000000), which requires
332 * 37-bits to represent the nanosecond value. Limit the
333 * slowest timing to what comedi handles (32-bits).
334 */
335 ns = divider * DT2811_OSC_BASE;
336 if (ns > COMEDI_MIN_SPEED)
337 continue;
338
339 /* Check for fastest found timing */
340 if (ns <= *nanosec && ns > ns_hi) {
341 ns_hi = ns;
342 divisor_hi = divisor;
343 }
344 /* Check for slowest found timing */
345 if (ns >= *nanosec && ns < ns_lo) {
346 ns_lo = ns;
347 divisor_lo = divisor;
348 }
349 }
350 }
351
352 /*
353 * The slowest found timing will be invalid if the requested timing
354 * is faster than what can be generated by the timer. Fix it so that
355 * CMDF_ROUND_UP returns valid timing.
356 */
357 if (ns_lo == COMEDI_MIN_SPEED) {
358 ns_lo = ns_hi;
359 divisor_lo = divisor_hi;
360 }
361 /*
362 * The fastest found timing will be invalid if the requested timing
363 * is less than what can be generated by the timer. Fix it so that
364 * CMDF_ROUND_NEAREST and CMDF_ROUND_DOWN return valid timing.
365 */
366 if (ns_hi == 0) {
367 ns_hi = ns_lo;
368 divisor_hi = divisor_lo;
369 }
370
371 switch (flags & CMDF_ROUND_MASK) {
372 case CMDF_ROUND_NEAREST:
373 default:
374 if (ns_hi - *nanosec < *nanosec - ns_lo) {
375 *nanosec = ns_lo;
376 return divisor_lo;
377 }
378 *nanosec = ns_hi;
379 return divisor_hi;
380 case CMDF_ROUND_UP:
381 *nanosec = ns_lo;
382 return divisor_lo;
383 case CMDF_ROUND_DOWN:
384 *nanosec = ns_hi;
385 return divisor_hi;
386 }
387}
388
389static int dt2811_ai_cmdtest(struct comedi_device *dev,
390 struct comedi_subdevice *s,
391 struct comedi_cmd *cmd)
392{
393 struct dt2811_private *devpriv = dev->private;
394 unsigned int arg;
395 int err = 0;
396
397 /* Step 1 : check if triggers are trivially valid */
398
399 err |= comedi_check_trigger_src(src: &cmd->start_src, TRIG_NOW | TRIG_EXT);
400 err |= comedi_check_trigger_src(src: &cmd->scan_begin_src, TRIG_FOLLOW);
401 err |= comedi_check_trigger_src(src: &cmd->convert_src,
402 TRIG_TIMER | TRIG_EXT);
403 err |= comedi_check_trigger_src(src: &cmd->scan_end_src, TRIG_COUNT);
404 err |= comedi_check_trigger_src(src: &cmd->stop_src, TRIG_COUNT | TRIG_NONE);
405
406 if (err)
407 return 1;
408
409 /* Step 2a : make sure trigger sources are unique */
410
411 err |= comedi_check_trigger_is_unique(src: cmd->start_src);
412 err |= comedi_check_trigger_is_unique(src: cmd->convert_src);
413 err |= comedi_check_trigger_is_unique(src: cmd->stop_src);
414
415 /* Step 2b : and mutually compatible */
416
417 if (cmd->convert_src == TRIG_EXT && cmd->start_src != TRIG_EXT)
418 err |= -EINVAL;
419
420 if (err)
421 return 2;
422
423 /* Step 3: check if arguments are trivially valid */
424
425 err |= comedi_check_trigger_arg_is(arg: &cmd->start_arg, val: 0);
426 err |= comedi_check_trigger_arg_is(arg: &cmd->scan_begin_arg, val: 0);
427 if (cmd->convert_src == TRIG_TIMER)
428 err |= comedi_check_trigger_arg_min(arg: &cmd->convert_arg, val: 12500);
429 err |= comedi_check_trigger_arg_is(arg: &cmd->scan_end_arg,
430 val: cmd->chanlist_len);
431 if (cmd->stop_src == TRIG_COUNT)
432 err |= comedi_check_trigger_arg_min(arg: &cmd->stop_arg, val: 1);
433 else /* TRIG_NONE */
434 err |= comedi_check_trigger_arg_is(arg: &cmd->stop_arg, val: 0);
435
436 if (err)
437 return 3;
438
439 /* Step 4: fix up any arguments */
440
441 if (cmd->convert_src == TRIG_TIMER) {
442 arg = cmd->convert_arg;
443 devpriv->ai_divisor = dt2811_ns_to_timer(nanosec: &arg, flags: cmd->flags);
444 err |= comedi_check_trigger_arg_is(arg: &cmd->convert_arg, val: arg);
445 } else { /* TRIG_EXT */
446 /* The convert_arg is used to set the divisor. */
447 devpriv->ai_divisor = cmd->convert_arg;
448 }
449
450 if (err)
451 return 4;
452
453 /* Step 5: check channel list if it exists */
454
455 return 0;
456}
457
458static int dt2811_ai_eoc(struct comedi_device *dev,
459 struct comedi_subdevice *s,
460 struct comedi_insn *insn,
461 unsigned long context)
462{
463 unsigned int status;
464
465 status = inb(port: dev->iobase + DT2811_ADCSR_REG);
466 if ((status & DT2811_ADCSR_ADBUSY) == 0)
467 return 0;
468 return -EBUSY;
469}
470
471static int dt2811_ai_insn_read(struct comedi_device *dev,
472 struct comedi_subdevice *s,
473 struct comedi_insn *insn,
474 unsigned int *data)
475{
476 int ret;
477 int i;
478
479 /* We will already be in Mode 0 */
480 for (i = 0; i < insn->n; i++) {
481 /* load chanspec and trigger conversion */
482 dt2811_ai_set_chanspec(dev, chanspec: insn->chanspec);
483
484 ret = comedi_timeout(dev, s, insn, cb: dt2811_ai_eoc, context: 0);
485 if (ret)
486 return ret;
487
488 data[i] = dt2811_ai_read_sample(dev, s);
489 }
490
491 return insn->n;
492}
493
494static int dt2811_ao_insn_write(struct comedi_device *dev,
495 struct comedi_subdevice *s,
496 struct comedi_insn *insn,
497 unsigned int *data)
498{
499 unsigned int chan = CR_CHAN(insn->chanspec);
500 unsigned int val = s->readback[chan];
501 int i;
502
503 for (i = 0; i < insn->n; i++) {
504 val = data[i];
505 outb(value: val & 0xff, port: dev->iobase + DT2811_DADATA_LO_REG(chan));
506 outb(value: (val >> 8) & 0xff,
507 port: dev->iobase + DT2811_DADATA_HI_REG(chan));
508 }
509 s->readback[chan] = val;
510
511 return insn->n;
512}
513
514static int dt2811_di_insn_bits(struct comedi_device *dev,
515 struct comedi_subdevice *s,
516 struct comedi_insn *insn,
517 unsigned int *data)
518{
519 data[1] = inb(port: dev->iobase + DT2811_DI_REG);
520
521 return insn->n;
522}
523
524static int dt2811_do_insn_bits(struct comedi_device *dev,
525 struct comedi_subdevice *s,
526 struct comedi_insn *insn,
527 unsigned int *data)
528{
529 if (comedi_dio_update_state(s, data))
530 outb(value: s->state, port: dev->iobase + DT2811_DO_REG);
531
532 data[1] = s->state;
533
534 return insn->n;
535}
536
537static void dt2811_reset(struct comedi_device *dev)
538{
539 /* This is the initialization sequence from the users manual */
540 outb(DT2811_ADCSR_ADMODE(0), port: dev->iobase + DT2811_ADCSR_REG);
541 usleep_range(min: 100, max: 1000);
542 inb(port: dev->iobase + DT2811_ADDATA_LO_REG);
543 inb(port: dev->iobase + DT2811_ADDATA_HI_REG);
544 outb(DT2811_ADCSR_ADMODE(0) | DT2811_ADCSR_CLRERROR,
545 port: dev->iobase + DT2811_ADCSR_REG);
546}
547
548static int dt2811_attach(struct comedi_device *dev, struct comedi_devconfig *it)
549{
550 const struct dt2811_board *board = dev->board_ptr;
551 struct dt2811_private *devpriv;
552 struct comedi_subdevice *s;
553 int ret;
554
555 devpriv = comedi_alloc_devpriv(dev, size: sizeof(*devpriv));
556 if (!devpriv)
557 return -ENOMEM;
558
559 ret = comedi_request_region(dev, start: it->options[0], len: 0x8);
560 if (ret)
561 return ret;
562
563 dt2811_reset(dev);
564
565 /* IRQ's 2,3,5,7 are valid for async command support */
566 if (it->options[1] <= 7 && (BIT(it->options[1]) & 0xac)) {
567 ret = request_irq(irq: it->options[1], handler: dt2811_interrupt, flags: 0,
568 name: dev->board_name, dev);
569 if (ret == 0)
570 dev->irq = it->options[1];
571 }
572
573 ret = comedi_alloc_subdevices(dev, num_subdevices: 4);
574 if (ret)
575 return ret;
576
577 /* Analog Input subdevice */
578 s = &dev->subdevices[0];
579 s->type = COMEDI_SUBD_AI;
580 s->subdev_flags = SDF_READABLE |
581 ((it->options[2] == 1) ? SDF_DIFF :
582 (it->options[2] == 2) ? SDF_COMMON : SDF_GROUND);
583 s->n_chan = (it->options[2] == 1) ? 8 : 16;
584 s->maxdata = 0x0fff;
585 s->range_table = board->is_pgh ? &dt2811_pgh_ai_ranges
586 : &dt2811_pgl_ai_ranges;
587 s->insn_read = dt2811_ai_insn_read;
588 if (dev->irq) {
589 dev->read_subdev = s;
590 s->subdev_flags |= SDF_CMD_READ;
591 s->len_chanlist = 1;
592 s->do_cmdtest = dt2811_ai_cmdtest;
593 s->do_cmd = dt2811_ai_cmd;
594 s->cancel = dt2811_ai_cancel;
595 }
596
597 /* Analog Output subdevice */
598 s = &dev->subdevices[1];
599 s->type = COMEDI_SUBD_AO;
600 s->subdev_flags = SDF_WRITABLE;
601 s->n_chan = 2;
602 s->maxdata = 0x0fff;
603 s->range_table = &dt2811_ao_ranges;
604 s->insn_write = dt2811_ao_insn_write;
605
606 ret = comedi_alloc_subdev_readback(s);
607 if (ret)
608 return ret;
609
610 /* Digital Input subdevice */
611 s = &dev->subdevices[2];
612 s->type = COMEDI_SUBD_DI;
613 s->subdev_flags = SDF_READABLE;
614 s->n_chan = 8;
615 s->maxdata = 1;
616 s->range_table = &range_digital;
617 s->insn_bits = dt2811_di_insn_bits;
618
619 /* Digital Output subdevice */
620 s = &dev->subdevices[3];
621 s->type = COMEDI_SUBD_DO;
622 s->subdev_flags = SDF_WRITABLE;
623 s->n_chan = 8;
624 s->maxdata = 1;
625 s->range_table = &range_digital;
626 s->insn_bits = dt2811_do_insn_bits;
627
628 return 0;
629}
630
631static struct comedi_driver dt2811_driver = {
632 .driver_name = "dt2811",
633 .module = THIS_MODULE,
634 .attach = dt2811_attach,
635 .detach = comedi_legacy_detach,
636 .board_name = &dt2811_boards[0].name,
637 .num_names = ARRAY_SIZE(dt2811_boards),
638 .offset = sizeof(struct dt2811_board),
639};
640module_comedi_driver(dt2811_driver);
641
642MODULE_AUTHOR("Comedi https://www.comedi.org");
643MODULE_DESCRIPTION("Comedi driver for Data Translation DT2811 series boards");
644MODULE_LICENSE("GPL");
645

source code of linux/drivers/comedi/drivers/dt2811.c