xref: /linux/drivers/comedi/drivers/pcl816.c (revision cbac924200b838cfb8d8b1415113d788089dc50b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * pcl816.c
4  * Comedi driver for Advantech PCL-816 cards
5  *
6  * Author:  Juan Grigera <juan@grigera.com.ar>
7  * based on pcl818 by Michal Dobes <dobes@tesnet.cz> and bits of pcl812
8  */
9 
10 /*
11  * Driver: pcl816
12  * Description: Advantech PCL-816 cards, PCL-814
13  * Devices: [Advantech] PCL-816 (pcl816), PCL-814B (pcl814b)
14  * Author: Juan Grigera <juan@grigera.com.ar>
15  * Status: works
16  * Updated: Tue,  2 Apr 2002 23:15:21 -0800
17  *
18  * PCL 816 and 814B have 16 SE/DIFF ADCs, 16 DACs, 16 DI and 16 DO.
19  * Differences are at resolution (16 vs 12 bits).
20  *
21  * The driver support AI command mode, other subdevices not written.
22  *
23  * Analog output and digital input and output are not supported.
24  *
25  * Configuration Options:
26  *   [0] - IO Base
27  *   [1] - IRQ	(0=disable, 2, 3, 4, 5, 6, 7)
28  *   [2] - DMA	(0=disable, 1, 3)
29  *   [3] - 0, 10=10MHz clock for 8254
30  *	       1= 1MHz clock for 8254
31  */
32 
33 #include <linux/module.h>
34 #include <linux/gfp.h>
35 #include <linux/delay.h>
36 #include <linux/io.h>
37 #include <linux/interrupt.h>
38 #include <linux/comedi/comedidev.h>
39 #include <linux/comedi/comedi_8254.h>
40 #include <linux/comedi/comedi_isadma.h>
41 
42 /*
43  * Register I/O map
44  */
45 #define PCL816_DO_DI_LSB_REG			0x00
46 #define PCL816_DO_DI_MSB_REG			0x01
47 #define PCL816_TIMER_BASE			0x04
48 #define PCL816_AI_LSB_REG			0x08
49 #define PCL816_AI_MSB_REG			0x09
50 #define PCL816_RANGE_REG			0x09
51 #define PCL816_CLRINT_REG			0x0a
52 #define PCL816_MUX_REG				0x0b
53 #define PCL816_MUX_SCAN(_first, _last)		(((_last) << 4) | (_first))
54 #define PCL816_CTRL_REG				0x0c
55 #define PCL816_CTRL_SOFT_TRIG			BIT(0)
56 #define PCL816_CTRL_PACER_TRIG			BIT(1)
57 #define PCL816_CTRL_EXT_TRIG			BIT(2)
58 #define PCL816_CTRL_POE				BIT(3)
59 #define PCL816_CTRL_DMAEN			BIT(4)
60 #define PCL816_CTRL_INTEN			BIT(5)
61 #define PCL816_CTRL_DMASRC_SLOT(x)		(((x) & 0x3) << 6)
62 #define PCL816_STATUS_REG			0x0d
63 #define PCL816_STATUS_NEXT_CHAN_MASK		(0xf << 0)
64 #define PCL816_STATUS_INTSRC_SLOT(x)		(((x) & 0x3) << 4)
65 #define PCL816_STATUS_INTSRC_DMA		PCL816_STATUS_INTSRC_SLOT(3)
66 #define PCL816_STATUS_INTSRC_MASK		PCL816_STATUS_INTSRC_SLOT(3)
67 #define PCL816_STATUS_INTACT			BIT(6)
68 #define PCL816_STATUS_DRDY			BIT(7)
69 
70 #define MAGIC_DMA_WORD 0x5a5a
71 
72 static const struct comedi_lrange range_pcl816 = {
73 	8, {
74 		BIP_RANGE(10),
75 		BIP_RANGE(5),
76 		BIP_RANGE(2.5),
77 		BIP_RANGE(1.25),
78 		UNI_RANGE(10),
79 		UNI_RANGE(5),
80 		UNI_RANGE(2.5),
81 		UNI_RANGE(1.25)
82 	}
83 };
84 
85 struct pcl816_board {
86 	const char *name;
87 	int ai_maxdata;
88 	int ai_chanlist;
89 };
90 
91 static const struct pcl816_board boardtypes[] = {
92 	{
93 		.name		= "pcl816",
94 		.ai_maxdata	= 0xffff,
95 		.ai_chanlist	= 1024,
96 	}, {
97 		.name		= "pcl814b",
98 		.ai_maxdata	= 0x3fff,
99 		.ai_chanlist	= 1024,
100 	},
101 };
102 
103 struct pcl816_private {
104 	struct comedi_isadma *dma;
105 	unsigned int ai_poll_ptr;	/*  how many sampes transfer poll */
106 	unsigned int ai_cmd_running:1;
107 	unsigned int ai_cmd_canceled:1;
108 };
109 
110 static void pcl816_ai_setup_dma(struct comedi_device *dev,
111 				struct comedi_subdevice *s,
112 				unsigned int unread_samples)
113 {
114 	struct pcl816_private *devpriv = dev->private;
115 	struct comedi_isadma *dma = devpriv->dma;
116 	struct comedi_isadma_desc *desc = &dma->desc[dma->cur_dma];
117 	unsigned int max_samples = comedi_bytes_to_samples(s, desc->maxsize);
118 	unsigned int nsamples;
119 
120 	comedi_isadma_disable(dma->chan);
121 
122 	/*
123 	 * Determine dma size based on the buffer maxsize plus the number of
124 	 * unread samples and the number of samples remaining in the command.
125 	 */
126 	nsamples = comedi_nsamples_left(s, max_samples + unread_samples);
127 	if (nsamples > unread_samples) {
128 		nsamples -= unread_samples;
129 		desc->size = comedi_samples_to_bytes(s, nsamples);
130 		comedi_isadma_program(desc);
131 	}
132 }
133 
134 static void pcl816_ai_set_chan_range(struct comedi_device *dev,
135 				     unsigned int chan,
136 				     unsigned int range)
137 {
138 	outb(chan, dev->iobase + PCL816_MUX_REG);
139 	outb(range, dev->iobase + PCL816_RANGE_REG);
140 }
141 
142 static void pcl816_ai_set_chan_scan(struct comedi_device *dev,
143 				    unsigned int first_chan,
144 				    unsigned int last_chan)
145 {
146 	outb(PCL816_MUX_SCAN(first_chan, last_chan),
147 	     dev->iobase + PCL816_MUX_REG);
148 }
149 
150 static void pcl816_ai_setup_chanlist(struct comedi_device *dev,
151 				     unsigned int *chanlist,
152 				     unsigned int seglen)
153 {
154 	unsigned int first_chan = CR_CHAN(chanlist[0]);
155 	unsigned int last_chan;
156 	unsigned int range;
157 	unsigned int i;
158 
159 	/* store range list to card */
160 	for (i = 0; i < seglen; i++) {
161 		last_chan = CR_CHAN(chanlist[i]);
162 		range = CR_RANGE(chanlist[i]);
163 
164 		pcl816_ai_set_chan_range(dev, last_chan, range);
165 	}
166 
167 	udelay(1);
168 
169 	pcl816_ai_set_chan_scan(dev, first_chan, last_chan);
170 }
171 
172 static void pcl816_ai_clear_eoc(struct comedi_device *dev)
173 {
174 	/* writing any value clears the interrupt request */
175 	outb(0, dev->iobase + PCL816_CLRINT_REG);
176 }
177 
178 static void pcl816_ai_soft_trig(struct comedi_device *dev)
179 {
180 	/* writing any value triggers a software conversion */
181 	outb(0, dev->iobase + PCL816_AI_LSB_REG);
182 }
183 
184 static unsigned int pcl816_ai_get_sample(struct comedi_device *dev,
185 					 struct comedi_subdevice *s)
186 {
187 	unsigned int val;
188 
189 	val = inb(dev->iobase + PCL816_AI_MSB_REG) << 8;
190 	val |= inb(dev->iobase + PCL816_AI_LSB_REG);
191 
192 	return val & s->maxdata;
193 }
194 
195 static int pcl816_ai_eoc(struct comedi_device *dev,
196 			 struct comedi_subdevice *s,
197 			 struct comedi_insn *insn,
198 			 unsigned long context)
199 {
200 	unsigned int status;
201 
202 	status = inb(dev->iobase + PCL816_STATUS_REG);
203 	if ((status & PCL816_STATUS_DRDY) == 0)
204 		return 0;
205 	return -EBUSY;
206 }
207 
208 static bool pcl816_ai_next_chan(struct comedi_device *dev,
209 				struct comedi_subdevice *s)
210 {
211 	struct comedi_cmd *cmd = &s->async->cmd;
212 
213 	if (cmd->stop_src == TRIG_COUNT &&
214 	    s->async->scans_done >= cmd->stop_arg) {
215 		s->async->events |= COMEDI_CB_EOA;
216 		return false;
217 	}
218 
219 	return true;
220 }
221 
222 static void transfer_from_dma_buf(struct comedi_device *dev,
223 				  struct comedi_subdevice *s,
224 				  unsigned short *ptr,
225 				  unsigned int bufptr, unsigned int len)
226 {
227 	unsigned short val;
228 	int i;
229 
230 	for (i = 0; i < len; i++) {
231 		val = ptr[bufptr++];
232 		comedi_buf_write_samples(s, &val, 1);
233 
234 		if (!pcl816_ai_next_chan(dev, s))
235 			return;
236 	}
237 }
238 
239 static irqreturn_t pcl816_interrupt(int irq, void *d)
240 {
241 	struct comedi_device *dev = d;
242 	struct comedi_subdevice *s = dev->read_subdev;
243 	struct pcl816_private *devpriv = dev->private;
244 	struct comedi_isadma *dma = devpriv->dma;
245 	struct comedi_isadma_desc *desc = &dma->desc[dma->cur_dma];
246 	unsigned int nsamples;
247 	unsigned int bufptr;
248 
249 	if (!dev->attached || !devpriv->ai_cmd_running) {
250 		pcl816_ai_clear_eoc(dev);
251 		return IRQ_HANDLED;
252 	}
253 
254 	if (devpriv->ai_cmd_canceled) {
255 		devpriv->ai_cmd_canceled = 0;
256 		pcl816_ai_clear_eoc(dev);
257 		return IRQ_HANDLED;
258 	}
259 
260 	nsamples = comedi_bytes_to_samples(s, desc->size) -
261 		   devpriv->ai_poll_ptr;
262 	bufptr = devpriv->ai_poll_ptr;
263 	devpriv->ai_poll_ptr = 0;
264 
265 	/* restart dma with the next buffer */
266 	dma->cur_dma = 1 - dma->cur_dma;
267 	pcl816_ai_setup_dma(dev, s, nsamples);
268 
269 	transfer_from_dma_buf(dev, s, desc->virt_addr, bufptr, nsamples);
270 
271 	pcl816_ai_clear_eoc(dev);
272 
273 	comedi_handle_events(dev, s);
274 	return IRQ_HANDLED;
275 }
276 
277 static int check_channel_list(struct comedi_device *dev,
278 			      struct comedi_subdevice *s,
279 			      unsigned int *chanlist,
280 			      unsigned int chanlen)
281 {
282 	unsigned int chansegment[16];
283 	unsigned int i, nowmustbechan, seglen;
284 
285 	/*  correct channel and range number check itself comedi/range.c */
286 	if (chanlen < 1) {
287 		dev_err(dev->class_dev, "range/channel list is empty!\n");
288 		return 0;
289 	}
290 
291 	if (chanlen > 1) {
292 		/*  first channel is every time ok */
293 		chansegment[0] = chanlist[0];
294 		for (i = 1, seglen = 1; i < chanlen; i++, seglen++) {
295 			/*  we detect loop, this must by finish */
296 			if (chanlist[0] == chanlist[i])
297 				break;
298 			nowmustbechan =
299 			    (CR_CHAN(chansegment[i - 1]) + 1) % chanlen;
300 			if (nowmustbechan != CR_CHAN(chanlist[i])) {
301 				/*  channel list isn't continuous :-( */
302 				dev_dbg(dev->class_dev,
303 					"channel list must be continuous! chanlist[%i]=%d but must be %d or %d!\n",
304 					i, CR_CHAN(chanlist[i]), nowmustbechan,
305 					CR_CHAN(chanlist[0]));
306 				return 0;
307 			}
308 			/*  well, this is next correct channel in list */
309 			chansegment[i] = chanlist[i];
310 		}
311 
312 		/*  check whole chanlist */
313 		for (i = 0; i < chanlen; i++) {
314 			if (chanlist[i] != chansegment[i % seglen]) {
315 				dev_dbg(dev->class_dev,
316 					"bad channel or range number! chanlist[%i]=%d,%d,%d and not %d,%d,%d!\n",
317 					i, CR_CHAN(chansegment[i]),
318 					CR_RANGE(chansegment[i]),
319 					CR_AREF(chansegment[i]),
320 					CR_CHAN(chanlist[i % seglen]),
321 					CR_RANGE(chanlist[i % seglen]),
322 					CR_AREF(chansegment[i % seglen]));
323 				return 0;	/*  chan/gain list is strange */
324 			}
325 		}
326 	} else {
327 		seglen = 1;
328 	}
329 
330 	return seglen;	/*  we can serve this with MUX logic */
331 }
332 
333 static int pcl816_ai_cmdtest(struct comedi_device *dev,
334 			     struct comedi_subdevice *s, struct comedi_cmd *cmd)
335 {
336 	int err = 0;
337 
338 	/* Step 1 : check if triggers are trivially valid */
339 
340 	err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW);
341 	err |= comedi_check_trigger_src(&cmd->scan_begin_src, TRIG_FOLLOW);
342 	err |= comedi_check_trigger_src(&cmd->convert_src,
343 					TRIG_EXT | TRIG_TIMER);
344 	err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
345 	err |= comedi_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
346 
347 	if (err)
348 		return 1;
349 
350 	/* Step 2a : make sure trigger sources are unique */
351 
352 	err |= comedi_check_trigger_is_unique(cmd->convert_src);
353 	err |= comedi_check_trigger_is_unique(cmd->stop_src);
354 
355 	/* Step 2b : and mutually compatible */
356 
357 	if (err)
358 		return 2;
359 
360 	/* Step 3: check if arguments are trivially valid */
361 
362 	err |= comedi_check_trigger_arg_is(&cmd->start_arg, 0);
363 	err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
364 
365 	if (cmd->convert_src == TRIG_TIMER)
366 		err |= comedi_check_trigger_arg_min(&cmd->convert_arg, 10000);
367 	else	/* TRIG_EXT */
368 		err |= comedi_check_trigger_arg_is(&cmd->convert_arg, 0);
369 
370 	err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg,
371 					   cmd->chanlist_len);
372 
373 	if (cmd->stop_src == TRIG_COUNT)
374 		err |= comedi_check_trigger_arg_min(&cmd->stop_arg, 1);
375 	else	/* TRIG_NONE */
376 		err |= comedi_check_trigger_arg_is(&cmd->stop_arg, 0);
377 
378 	if (err)
379 		return 3;
380 
381 	/* step 4: fix up any arguments */
382 	if (cmd->convert_src == TRIG_TIMER) {
383 		unsigned int arg = cmd->convert_arg;
384 
385 		comedi_8254_cascade_ns_to_timer(dev->pacer, &arg, cmd->flags);
386 		err |= comedi_check_trigger_arg_is(&cmd->convert_arg, arg);
387 	}
388 
389 	if (err)
390 		return 4;
391 
392 	/* step 5: complain about special chanlist considerations */
393 
394 	if (cmd->chanlist) {
395 		if (!check_channel_list(dev, s, cmd->chanlist,
396 					cmd->chanlist_len))
397 			return 5;	/*  incorrect channels list */
398 	}
399 
400 	return 0;
401 }
402 
403 static int pcl816_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
404 {
405 	struct pcl816_private *devpriv = dev->private;
406 	struct comedi_isadma *dma = devpriv->dma;
407 	struct comedi_cmd *cmd = &s->async->cmd;
408 	unsigned int ctrl;
409 	unsigned int seglen;
410 
411 	if (devpriv->ai_cmd_running)
412 		return -EBUSY;
413 
414 	seglen = check_channel_list(dev, s, cmd->chanlist, cmd->chanlist_len);
415 	if (seglen < 1)
416 		return -EINVAL;
417 	pcl816_ai_setup_chanlist(dev, cmd->chanlist, seglen);
418 	udelay(1);
419 
420 	devpriv->ai_cmd_running = 1;
421 	devpriv->ai_poll_ptr = 0;
422 	devpriv->ai_cmd_canceled = 0;
423 
424 	/* setup and enable dma for the first buffer */
425 	dma->cur_dma = 0;
426 	pcl816_ai_setup_dma(dev, s, 0);
427 
428 	comedi_8254_set_mode(dev->pacer, 0, I8254_MODE1 | I8254_BINARY);
429 	comedi_8254_write(dev->pacer, 0, 0x0ff);
430 	udelay(1);
431 	comedi_8254_update_divisors(dev->pacer);
432 	comedi_8254_pacer_enable(dev->pacer, 1, 2, true);
433 
434 	ctrl = PCL816_CTRL_INTEN | PCL816_CTRL_DMAEN |
435 	       PCL816_CTRL_DMASRC_SLOT(0);
436 	if (cmd->convert_src == TRIG_TIMER)
437 		ctrl |= PCL816_CTRL_PACER_TRIG;
438 	else	/* TRIG_EXT */
439 		ctrl |= PCL816_CTRL_EXT_TRIG;
440 
441 	outb(ctrl, dev->iobase + PCL816_CTRL_REG);
442 	outb((dma->chan << 4) | dev->irq,
443 	     dev->iobase + PCL816_STATUS_REG);
444 
445 	return 0;
446 }
447 
448 static int pcl816_ai_poll(struct comedi_device *dev, struct comedi_subdevice *s)
449 {
450 	struct pcl816_private *devpriv = dev->private;
451 	struct comedi_isadma *dma = devpriv->dma;
452 	struct comedi_isadma_desc *desc;
453 	unsigned long flags;
454 	unsigned int poll;
455 	int ret;
456 
457 	spin_lock_irqsave(&dev->spinlock, flags);
458 
459 	poll = comedi_isadma_poll(dma);
460 	poll = comedi_bytes_to_samples(s, poll);
461 	if (poll > devpriv->ai_poll_ptr) {
462 		desc = &dma->desc[dma->cur_dma];
463 		transfer_from_dma_buf(dev, s, desc->virt_addr,
464 				      devpriv->ai_poll_ptr,
465 				      poll - devpriv->ai_poll_ptr);
466 		/* new buffer position */
467 		devpriv->ai_poll_ptr = poll;
468 
469 		comedi_handle_events(dev, s);
470 
471 		ret = comedi_buf_n_bytes_ready(s);
472 	} else {
473 		/* no new samples */
474 		ret = 0;
475 	}
476 	spin_unlock_irqrestore(&dev->spinlock, flags);
477 
478 	return ret;
479 }
480 
481 static int pcl816_ai_cancel(struct comedi_device *dev,
482 			    struct comedi_subdevice *s)
483 {
484 	struct pcl816_private *devpriv = dev->private;
485 
486 	if (!devpriv->ai_cmd_running)
487 		return 0;
488 
489 	outb(0, dev->iobase + PCL816_CTRL_REG);
490 	pcl816_ai_clear_eoc(dev);
491 
492 	comedi_8254_pacer_enable(dev->pacer, 1, 2, false);
493 
494 	devpriv->ai_cmd_running = 0;
495 	devpriv->ai_cmd_canceled = 1;
496 
497 	return 0;
498 }
499 
500 static int pcl816_ai_insn_read(struct comedi_device *dev,
501 			       struct comedi_subdevice *s,
502 			       struct comedi_insn *insn,
503 			       unsigned int *data)
504 {
505 	unsigned int chan = CR_CHAN(insn->chanspec);
506 	unsigned int range = CR_RANGE(insn->chanspec);
507 	int ret = 0;
508 	int i;
509 
510 	outb(PCL816_CTRL_SOFT_TRIG, dev->iobase + PCL816_CTRL_REG);
511 
512 	pcl816_ai_set_chan_range(dev, chan, range);
513 	pcl816_ai_set_chan_scan(dev, chan, chan);
514 
515 	for (i = 0; i < insn->n; i++) {
516 		pcl816_ai_clear_eoc(dev);
517 		pcl816_ai_soft_trig(dev);
518 
519 		ret = comedi_timeout(dev, s, insn, pcl816_ai_eoc, 0);
520 		if (ret)
521 			break;
522 
523 		data[i] = pcl816_ai_get_sample(dev, s);
524 	}
525 	outb(0, dev->iobase + PCL816_CTRL_REG);
526 	pcl816_ai_clear_eoc(dev);
527 
528 	return ret ? ret : insn->n;
529 }
530 
531 static int pcl816_di_insn_bits(struct comedi_device *dev,
532 			       struct comedi_subdevice *s,
533 			       struct comedi_insn *insn,
534 			       unsigned int *data)
535 {
536 	data[1] = inb(dev->iobase + PCL816_DO_DI_LSB_REG) |
537 		  (inb(dev->iobase + PCL816_DO_DI_MSB_REG) << 8);
538 
539 	return insn->n;
540 }
541 
542 static int pcl816_do_insn_bits(struct comedi_device *dev,
543 			       struct comedi_subdevice *s,
544 			       struct comedi_insn *insn,
545 			       unsigned int *data)
546 {
547 	if (comedi_dio_update_state(s, data)) {
548 		outb(s->state & 0xff, dev->iobase + PCL816_DO_DI_LSB_REG);
549 		outb((s->state >> 8), dev->iobase + PCL816_DO_DI_MSB_REG);
550 	}
551 
552 	data[1] = s->state;
553 
554 	return insn->n;
555 }
556 
557 static void pcl816_reset(struct comedi_device *dev)
558 {
559 	outb(0, dev->iobase + PCL816_CTRL_REG);
560 	pcl816_ai_set_chan_range(dev, 0, 0);
561 	pcl816_ai_clear_eoc(dev);
562 
563 	/* set all digital outputs low */
564 	outb(0, dev->iobase + PCL816_DO_DI_LSB_REG);
565 	outb(0, dev->iobase + PCL816_DO_DI_MSB_REG);
566 }
567 
568 static void pcl816_alloc_irq_and_dma(struct comedi_device *dev,
569 				     struct comedi_devconfig *it)
570 {
571 	struct pcl816_private *devpriv = dev->private;
572 	unsigned int irq_num = it->options[1];
573 	unsigned int dma_chan = it->options[2];
574 
575 	/* only IRQs 2-7 and DMA channels 3 and 1 are valid */
576 	if (!(irq_num >= 2 && irq_num <= 7) ||
577 	    !(dma_chan == 3 || dma_chan == 1))
578 		return;
579 
580 	if (request_irq(irq_num, pcl816_interrupt, 0, dev->board_name, dev))
581 		return;
582 
583 	/* DMA uses two 16K buffers */
584 	devpriv->dma = comedi_isadma_alloc(dev, 2, dma_chan, dma_chan,
585 					   PAGE_SIZE * 4, COMEDI_ISADMA_READ);
586 	if (!devpriv->dma)
587 		free_irq(irq_num, dev);
588 	else
589 		dev->irq = irq_num;
590 }
591 
592 static void pcl816_free_dma(struct comedi_device *dev)
593 {
594 	struct pcl816_private *devpriv = dev->private;
595 
596 	if (devpriv)
597 		comedi_isadma_free(devpriv->dma);
598 }
599 
600 static int pcl816_attach(struct comedi_device *dev, struct comedi_devconfig *it)
601 {
602 	const struct pcl816_board *board = dev->board_ptr;
603 	struct pcl816_private *devpriv;
604 	struct comedi_subdevice *s;
605 	int ret;
606 
607 	devpriv = comedi_alloc_devpriv(dev, sizeof(*devpriv));
608 	if (!devpriv)
609 		return -ENOMEM;
610 
611 	ret = comedi_request_region(dev, it->options[0], 0x10);
612 	if (ret)
613 		return ret;
614 
615 	/* an IRQ and DMA are required to support async commands */
616 	pcl816_alloc_irq_and_dma(dev, it);
617 
618 	dev->pacer = comedi_8254_init(dev->iobase + PCL816_TIMER_BASE,
619 				      I8254_OSC_BASE_10MHZ, I8254_IO8, 0);
620 	if (!dev->pacer)
621 		return -ENOMEM;
622 
623 	ret = comedi_alloc_subdevices(dev, 4);
624 	if (ret)
625 		return ret;
626 
627 	s = &dev->subdevices[0];
628 	s->type		= COMEDI_SUBD_AI;
629 	s->subdev_flags	= SDF_CMD_READ | SDF_DIFF;
630 	s->n_chan	= 16;
631 	s->maxdata	= board->ai_maxdata;
632 	s->range_table	= &range_pcl816;
633 	s->insn_read	= pcl816_ai_insn_read;
634 	if (dev->irq) {
635 		dev->read_subdev = s;
636 		s->subdev_flags	|= SDF_CMD_READ;
637 		s->len_chanlist	= board->ai_chanlist;
638 		s->do_cmdtest	= pcl816_ai_cmdtest;
639 		s->do_cmd	= pcl816_ai_cmd;
640 		s->poll		= pcl816_ai_poll;
641 		s->cancel	= pcl816_ai_cancel;
642 	}
643 
644 	/* Piggyback Slot1 subdevice */
645 	s = &dev->subdevices[1];
646 	s->type		= COMEDI_SUBD_UNUSED;
647 
648 	/* Digital Input subdevice */
649 	s = &dev->subdevices[2];
650 	s->type		= COMEDI_SUBD_DI;
651 	s->subdev_flags	= SDF_READABLE;
652 	s->n_chan	= 16;
653 	s->maxdata	= 1;
654 	s->range_table	= &range_digital;
655 	s->insn_bits	= pcl816_di_insn_bits;
656 
657 	/* Digital Output subdevice */
658 	s = &dev->subdevices[3];
659 	s->type		= COMEDI_SUBD_DO;
660 	s->subdev_flags	= SDF_WRITABLE;
661 	s->n_chan	= 16;
662 	s->maxdata	= 1;
663 	s->range_table	= &range_digital;
664 	s->insn_bits	= pcl816_do_insn_bits;
665 
666 	pcl816_reset(dev);
667 
668 	return 0;
669 }
670 
671 static void pcl816_detach(struct comedi_device *dev)
672 {
673 	if (dev->private) {
674 		pcl816_ai_cancel(dev, dev->read_subdev);
675 		pcl816_reset(dev);
676 	}
677 	pcl816_free_dma(dev);
678 	comedi_legacy_detach(dev);
679 }
680 
681 static struct comedi_driver pcl816_driver = {
682 	.driver_name	= "pcl816",
683 	.module		= THIS_MODULE,
684 	.attach		= pcl816_attach,
685 	.detach		= pcl816_detach,
686 	.board_name	= &boardtypes[0].name,
687 	.num_names	= ARRAY_SIZE(boardtypes),
688 	.offset		= sizeof(struct pcl816_board),
689 };
690 module_comedi_driver(pcl816_driver);
691 
692 MODULE_AUTHOR("Comedi https://www.comedi.org");
693 MODULE_DESCRIPTION("Comedi low-level driver");
694 MODULE_LICENSE("GPL");
695