1/*
2    comedi/drivers/das16m1.c
3    CIO-DAS16/M1 driver
4    Author: Frank Mori Hess, based on code from the das16
5      driver.
6    Copyright (C) 2001 Frank Mori Hess <fmhess@users.sourceforge.net>
7
8    COMEDI - Linux Control and Measurement Device Interface
9    Copyright (C) 2000 David A. Schleef <ds@schleef.org>
10
11    This program is free software; you can redistribute it and/or modify
12    it under the terms of the GNU General Public License as published by
13    the Free Software Foundation; either version 2 of the License, or
14    (at your option) any later version.
15
16    This program is distributed in the hope that it will be useful,
17    but WITHOUT ANY WARRANTY; without even the implied warranty of
18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19    GNU General Public License for more details.
20*/
21/*
22Driver: das16m1
23Description: CIO-DAS16/M1
24Author: Frank Mori Hess <fmhess@users.sourceforge.net>
25Devices: [Measurement Computing] CIO-DAS16/M1 (das16m1)
26Status: works
27
28This driver supports a single board - the CIO-DAS16/M1.
29As far as I know, there are no other boards that have
30the same register layout.  Even the CIO-DAS16/M1/16 is
31significantly different.
32
33I was _barely_ able to reach the full 1 MHz capability
34of this board, using a hard real-time interrupt
35(set the TRIG_RT flag in your struct comedi_cmd and use
36rtlinux or RTAI).  The board can't do dma, so the bottleneck is
37pulling the data across the ISA bus.  I timed the interrupt
38handler, and it took my computer ~470 microseconds to pull 512
39samples from the board.  So at 1 Mhz sampling rate,
40expect your CPU to be spending almost all of its
41time in the interrupt handler.
42
43This board has some unusual restrictions for its channel/gain list.  If the
44list has 2 or more channels in it, then two conditions must be satisfied:
45(1) - even/odd channels must appear at even/odd indices in the list
46(2) - the list must have an even number of entries.
47
48Options:
49        [0] - base io address
50        [1] - irq (optional, but you probably want it)
51
52irq can be omitted, although the cmd interface will not work without it.
53*/
54
55#include <linux/module.h>
56#include <linux/slab.h>
57#include <linux/interrupt.h>
58#include "../comedidev.h"
59
60#include "8255.h"
61#include "comedi_8254.h"
62
63#define DAS16M1_SIZE2 8
64
65#define FIFO_SIZE 1024		/*  1024 sample fifo */
66
67/*
68    CIO-DAS16_M1.pdf
69
70    "cio-das16/m1"
71
72  0	a/d bits 0-3, mux		start 12 bit
73  1	a/d bits 4-11		unused
74  2	status		control
75  3	di 4 bit		do 4 bit
76  4	unused			clear interrupt
77  5	interrupt, pacer
78  6	channel/gain queue address
79  7	channel/gain queue data
80  89ab	8254
81  cdef	8254
82  400	8255
83  404-407 	8254
84
85*/
86
87#define DAS16M1_AI             0	/*  16-bit wide register */
88#define   AI_CHAN(x)             ((x) & 0xf)
89#define DAS16M1_CS             2
90#define   EXT_TRIG_BIT           0x1
91#define   OVRUN                  0x20
92#define   IRQDATA                0x80
93#define DAS16M1_DIO            3
94#define DAS16M1_CLEAR_INTR     4
95#define DAS16M1_INTR_CONTROL   5
96#define   EXT_PACER              0x2
97#define   INT_PACER              0x3
98#define   PACER_MASK             0x3
99#define   INTE                   0x80
100#define DAS16M1_QUEUE_ADDR     6
101#define DAS16M1_QUEUE_DATA     7
102#define   Q_CHAN(x)              ((x) & 0x7)
103#define   Q_RANGE(x)             (((x) & 0xf) << 4)
104#define   UNIPOLAR               0x40
105#define DAS16M1_8254_FIRST             0x8
106#define DAS16M1_8254_SECOND            0xc
107#define DAS16M1_82C55                  0x400
108#define DAS16M1_8254_THIRD             0x404
109
110static const struct comedi_lrange range_das16m1 = {
111	9, {
112		BIP_RANGE(5),
113		BIP_RANGE(2.5),
114		BIP_RANGE(1.25),
115		BIP_RANGE(0.625),
116		UNI_RANGE(10),
117		UNI_RANGE(5),
118		UNI_RANGE(2.5),
119		UNI_RANGE(1.25),
120		BIP_RANGE(10)
121	}
122};
123
124struct das16m1_private_struct {
125	struct comedi_8254 *counter;
126	unsigned int control_state;
127	unsigned int adc_count;	/*  number of samples completed */
128	/* initial value in lower half of hardware conversion counter,
129	 * needed to keep track of whether new count has been loaded into
130	 * counter yet (loaded by first sample conversion) */
131	u16 initial_hw_count;
132	unsigned short ai_buffer[FIFO_SIZE];
133	unsigned long extra_iobase;
134};
135
136static inline unsigned short munge_sample(unsigned short data)
137{
138	return (data >> 4) & 0xfff;
139}
140
141static void munge_sample_array(unsigned short *array, unsigned int num_elements)
142{
143	unsigned int i;
144
145	for (i = 0; i < num_elements; i++)
146		array[i] = munge_sample(array[i]);
147}
148
149static int das16m1_ai_check_chanlist(struct comedi_device *dev,
150				     struct comedi_subdevice *s,
151				     struct comedi_cmd *cmd)
152{
153	int i;
154
155	if (cmd->chanlist_len == 1)
156		return 0;
157
158	if ((cmd->chanlist_len % 2) != 0) {
159		dev_dbg(dev->class_dev,
160			"chanlist must be of even length or length 1\n");
161		return -EINVAL;
162	}
163
164	for (i = 0; i < cmd->chanlist_len; i++) {
165		unsigned int chan = CR_CHAN(cmd->chanlist[i]);
166
167		if ((i % 2) != (chan % 2)) {
168			dev_dbg(dev->class_dev,
169				"even/odd channels must go have even/odd chanlist indices\n");
170			return -EINVAL;
171		}
172	}
173
174	return 0;
175}
176
177static int das16m1_cmd_test(struct comedi_device *dev,
178			    struct comedi_subdevice *s, struct comedi_cmd *cmd)
179{
180	int err = 0;
181
182	/* Step 1 : check if triggers are trivially valid */
183
184	err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_EXT);
185	err |= comedi_check_trigger_src(&cmd->scan_begin_src, TRIG_FOLLOW);
186	err |= comedi_check_trigger_src(&cmd->convert_src,
187					TRIG_TIMER | TRIG_EXT);
188	err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
189	err |= comedi_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
190
191	if (err)
192		return 1;
193
194	/* Step 2a : make sure trigger sources are unique */
195
196	err |= comedi_check_trigger_is_unique(cmd->start_src);
197	err |= comedi_check_trigger_is_unique(cmd->convert_src);
198	err |= comedi_check_trigger_is_unique(cmd->stop_src);
199
200	/* Step 2b : and mutually compatible */
201
202	if (err)
203		return 2;
204
205	/* Step 3: check if arguments are trivially valid */
206
207	err |= comedi_check_trigger_arg_is(&cmd->start_arg, 0);
208
209	if (cmd->scan_begin_src == TRIG_FOLLOW)	/* internal trigger */
210		err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
211
212	if (cmd->convert_src == TRIG_TIMER)
213		err |= comedi_check_trigger_arg_min(&cmd->convert_arg, 1000);
214
215	err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg,
216					   cmd->chanlist_len);
217
218	if (cmd->stop_src == TRIG_COUNT)
219		err |= comedi_check_trigger_arg_min(&cmd->stop_arg, 1);
220	else	/* TRIG_NONE */
221		err |= comedi_check_trigger_arg_is(&cmd->stop_arg, 0);
222
223	if (err)
224		return 3;
225
226	/* step 4: fix up arguments */
227
228	if (cmd->convert_src == TRIG_TIMER) {
229		unsigned int arg = cmd->convert_arg;
230
231		comedi_8254_cascade_ns_to_timer(dev->pacer, &arg, cmd->flags);
232		err |= comedi_check_trigger_arg_is(&cmd->convert_arg, arg);
233	}
234
235	if (err)
236		return 4;
237
238	/* Step 5: check channel list if it exists */
239	if (cmd->chanlist && cmd->chanlist_len > 0)
240		err |= das16m1_ai_check_chanlist(dev, s, cmd);
241
242	if (err)
243		return 5;
244
245	return 0;
246}
247
248static int das16m1_cmd_exec(struct comedi_device *dev,
249			    struct comedi_subdevice *s)
250{
251	struct das16m1_private_struct *devpriv = dev->private;
252	struct comedi_async *async = s->async;
253	struct comedi_cmd *cmd = &async->cmd;
254	unsigned int byte, i;
255
256	/* disable interrupts and internal pacer */
257	devpriv->control_state &= ~INTE & ~PACER_MASK;
258	outb(devpriv->control_state, dev->iobase + DAS16M1_INTR_CONTROL);
259
260	/*  set software count */
261	devpriv->adc_count = 0;
262
263	/*
264	 * Initialize lower half of hardware counter, used to determine how
265	 * many samples are in fifo.  Value doesn't actually load into counter
266	 * until counter's next clock (the next a/d conversion).
267	 */
268	comedi_8254_set_mode(devpriv->counter, 1, I8254_MODE2 | I8254_BINARY);
269	comedi_8254_write(devpriv->counter, 1, 0);
270
271	/*
272	 * Remember current reading of counter so we know when counter has
273	 * actually been loaded.
274	 */
275	devpriv->initial_hw_count = comedi_8254_read(devpriv->counter, 1);
276
277	/* setup channel/gain queue */
278	for (i = 0; i < cmd->chanlist_len; i++) {
279		outb(i, dev->iobase + DAS16M1_QUEUE_ADDR);
280		byte =
281		    Q_CHAN(CR_CHAN(cmd->chanlist[i])) |
282		    Q_RANGE(CR_RANGE(cmd->chanlist[i]));
283		outb(byte, dev->iobase + DAS16M1_QUEUE_DATA);
284	}
285
286	/* enable interrupts and set internal pacer counter mode and counts */
287	devpriv->control_state &= ~PACER_MASK;
288	if (cmd->convert_src == TRIG_TIMER) {
289		comedi_8254_update_divisors(dev->pacer);
290		comedi_8254_pacer_enable(dev->pacer, 1, 2, true);
291		devpriv->control_state |= INT_PACER;
292	} else {	/* TRIG_EXT */
293		devpriv->control_state |= EXT_PACER;
294	}
295
296	/*  set control & status register */
297	byte = 0;
298	/* if we are using external start trigger (also board dislikes having
299	 * both start and conversion triggers external simultaneously) */
300	if (cmd->start_src == TRIG_EXT && cmd->convert_src != TRIG_EXT)
301		byte |= EXT_TRIG_BIT;
302
303	outb(byte, dev->iobase + DAS16M1_CS);
304	/* clear interrupt bit */
305	outb(0, dev->iobase + DAS16M1_CLEAR_INTR);
306
307	devpriv->control_state |= INTE;
308	outb(devpriv->control_state, dev->iobase + DAS16M1_INTR_CONTROL);
309
310	return 0;
311}
312
313static int das16m1_cancel(struct comedi_device *dev, struct comedi_subdevice *s)
314{
315	struct das16m1_private_struct *devpriv = dev->private;
316
317	devpriv->control_state &= ~INTE & ~PACER_MASK;
318	outb(devpriv->control_state, dev->iobase + DAS16M1_INTR_CONTROL);
319
320	return 0;
321}
322
323static int das16m1_ai_eoc(struct comedi_device *dev,
324			  struct comedi_subdevice *s,
325			  struct comedi_insn *insn,
326			  unsigned long context)
327{
328	unsigned int status;
329
330	status = inb(dev->iobase + DAS16M1_CS);
331	if (status & IRQDATA)
332		return 0;
333	return -EBUSY;
334}
335
336static int das16m1_ai_rinsn(struct comedi_device *dev,
337			    struct comedi_subdevice *s,
338			    struct comedi_insn *insn, unsigned int *data)
339{
340	struct das16m1_private_struct *devpriv = dev->private;
341	int ret;
342	int n;
343	int byte;
344
345	/* disable interrupts and internal pacer */
346	devpriv->control_state &= ~INTE & ~PACER_MASK;
347	outb(devpriv->control_state, dev->iobase + DAS16M1_INTR_CONTROL);
348
349	/* setup channel/gain queue */
350	outb(0, dev->iobase + DAS16M1_QUEUE_ADDR);
351	byte =
352	    Q_CHAN(CR_CHAN(insn->chanspec)) | Q_RANGE(CR_RANGE(insn->chanspec));
353	outb(byte, dev->iobase + DAS16M1_QUEUE_DATA);
354
355	for (n = 0; n < insn->n; n++) {
356		/* clear IRQDATA bit */
357		outb(0, dev->iobase + DAS16M1_CLEAR_INTR);
358		/* trigger conversion */
359		outb(0, dev->iobase);
360
361		ret = comedi_timeout(dev, s, insn, das16m1_ai_eoc, 0);
362		if (ret)
363			return ret;
364
365		data[n] = munge_sample(inw(dev->iobase));
366	}
367
368	return n;
369}
370
371static int das16m1_di_rbits(struct comedi_device *dev,
372			    struct comedi_subdevice *s,
373			    struct comedi_insn *insn, unsigned int *data)
374{
375	unsigned int bits;
376
377	bits = inb(dev->iobase + DAS16M1_DIO) & 0xf;
378	data[1] = bits;
379	data[0] = 0;
380
381	return insn->n;
382}
383
384static int das16m1_do_wbits(struct comedi_device *dev,
385			    struct comedi_subdevice *s,
386			    struct comedi_insn *insn,
387			    unsigned int *data)
388{
389	if (comedi_dio_update_state(s, data))
390		outb(s->state, dev->iobase + DAS16M1_DIO);
391
392	data[1] = s->state;
393
394	return insn->n;
395}
396
397static void das16m1_handler(struct comedi_device *dev, unsigned int status)
398{
399	struct das16m1_private_struct *devpriv = dev->private;
400	struct comedi_subdevice *s;
401	struct comedi_async *async;
402	struct comedi_cmd *cmd;
403	u16 num_samples;
404	u16 hw_counter;
405
406	s = dev->read_subdev;
407	async = s->async;
408	cmd = &async->cmd;
409
410	/* figure out how many samples are in fifo */
411	hw_counter = comedi_8254_read(devpriv->counter, 1);
412	/* make sure hardware counter reading is not bogus due to initial value
413	 * not having been loaded yet */
414	if (devpriv->adc_count == 0 && hw_counter == devpriv->initial_hw_count) {
415		num_samples = 0;
416	} else {
417		/* The calculation of num_samples looks odd, but it uses the following facts.
418		 * 16 bit hardware counter is initialized with value of zero (which really
419		 * means 0x1000).  The counter decrements by one on each conversion
420		 * (when the counter decrements from zero it goes to 0xffff).  num_samples
421		 * is a 16 bit variable, so it will roll over in a similar fashion to the
422		 * hardware counter.  Work it out, and this is what you get. */
423		num_samples = -hw_counter - devpriv->adc_count;
424	}
425	/*  check if we only need some of the points */
426	if (cmd->stop_src == TRIG_COUNT) {
427		if (num_samples > cmd->stop_arg * cmd->chanlist_len)
428			num_samples = cmd->stop_arg * cmd->chanlist_len;
429	}
430	/*  make sure we dont try to get too many points if fifo has overrun */
431	if (num_samples > FIFO_SIZE)
432		num_samples = FIFO_SIZE;
433	insw(dev->iobase, devpriv->ai_buffer, num_samples);
434	munge_sample_array(devpriv->ai_buffer, num_samples);
435	comedi_buf_write_samples(s, devpriv->ai_buffer, num_samples);
436	devpriv->adc_count += num_samples;
437
438	if (cmd->stop_src == TRIG_COUNT) {
439		if (devpriv->adc_count >= cmd->stop_arg * cmd->chanlist_len) {
440			/* end of acquisition */
441			async->events |= COMEDI_CB_EOA;
442		}
443	}
444
445	/* this probably won't catch overruns since the card doesn't generate
446	 * overrun interrupts, but we might as well try */
447	if (status & OVRUN) {
448		async->events |= COMEDI_CB_ERROR;
449		dev_err(dev->class_dev, "fifo overflow\n");
450	}
451
452	comedi_handle_events(dev, s);
453}
454
455static int das16m1_poll(struct comedi_device *dev, struct comedi_subdevice *s)
456{
457	unsigned long flags;
458	unsigned int status;
459
460	/*  prevent race with interrupt handler */
461	spin_lock_irqsave(&dev->spinlock, flags);
462	status = inb(dev->iobase + DAS16M1_CS);
463	das16m1_handler(dev, status);
464	spin_unlock_irqrestore(&dev->spinlock, flags);
465
466	return comedi_buf_n_bytes_ready(s);
467}
468
469static irqreturn_t das16m1_interrupt(int irq, void *d)
470{
471	int status;
472	struct comedi_device *dev = d;
473
474	if (!dev->attached) {
475		dev_err(dev->class_dev, "premature interrupt\n");
476		return IRQ_HANDLED;
477	}
478	/*  prevent race with comedi_poll() */
479	spin_lock(&dev->spinlock);
480
481	status = inb(dev->iobase + DAS16M1_CS);
482
483	if ((status & (IRQDATA | OVRUN)) == 0) {
484		dev_err(dev->class_dev, "spurious interrupt\n");
485		spin_unlock(&dev->spinlock);
486		return IRQ_NONE;
487	}
488
489	das16m1_handler(dev, status);
490
491	/* clear interrupt */
492	outb(0, dev->iobase + DAS16M1_CLEAR_INTR);
493
494	spin_unlock(&dev->spinlock);
495	return IRQ_HANDLED;
496}
497
498static int das16m1_irq_bits(unsigned int irq)
499{
500	switch (irq) {
501	case 10:
502		return 0x0;
503	case 11:
504		return 0x1;
505	case 12:
506		return 0x2;
507	case 15:
508		return 0x3;
509	case 2:
510		return 0x4;
511	case 3:
512		return 0x5;
513	case 5:
514		return 0x6;
515	case 7:
516		return 0x7;
517	default:
518		return 0x0;
519	}
520}
521
522/*
523 * Options list:
524 *   0  I/O base
525 *   1  IRQ
526 */
527static int das16m1_attach(struct comedi_device *dev,
528			  struct comedi_devconfig *it)
529{
530	struct das16m1_private_struct *devpriv;
531	struct comedi_subdevice *s;
532	int ret;
533
534	devpriv = comedi_alloc_devpriv(dev, sizeof(*devpriv));
535	if (!devpriv)
536		return -ENOMEM;
537
538	ret = comedi_request_region(dev, it->options[0], 0x10);
539	if (ret)
540		return ret;
541	/* Request an additional region for the 8255 */
542	ret = __comedi_request_region(dev, dev->iobase + DAS16M1_82C55,
543				      DAS16M1_SIZE2);
544	if (ret)
545		return ret;
546	devpriv->extra_iobase = dev->iobase + DAS16M1_82C55;
547
548	/* only irqs 2, 3, 4, 5, 6, 7, 10, 11, 12, 14, and 15 are valid */
549	if ((1 << it->options[1]) & 0xdcfc) {
550		ret = request_irq(it->options[1], das16m1_interrupt, 0,
551				  dev->board_name, dev);
552		if (ret == 0)
553			dev->irq = it->options[1];
554	}
555
556	dev->pacer = comedi_8254_init(dev->iobase + DAS16M1_8254_SECOND,
557				      I8254_OSC_BASE_10MHZ, I8254_IO8, 0);
558	if (!dev->pacer)
559		return -ENOMEM;
560
561	devpriv->counter = comedi_8254_init(dev->iobase + DAS16M1_8254_FIRST,
562					    0, I8254_IO8, 0);
563	if (!devpriv->counter)
564		return -ENOMEM;
565
566	ret = comedi_alloc_subdevices(dev, 4);
567	if (ret)
568		return ret;
569
570	s = &dev->subdevices[0];
571	/* ai */
572	s->type = COMEDI_SUBD_AI;
573	s->subdev_flags = SDF_READABLE | SDF_DIFF;
574	s->n_chan = 8;
575	s->maxdata = (1 << 12) - 1;
576	s->range_table = &range_das16m1;
577	s->insn_read = das16m1_ai_rinsn;
578	if (dev->irq) {
579		dev->read_subdev = s;
580		s->subdev_flags |= SDF_CMD_READ;
581		s->len_chanlist = 256;
582		s->do_cmdtest = das16m1_cmd_test;
583		s->do_cmd = das16m1_cmd_exec;
584		s->cancel = das16m1_cancel;
585		s->poll = das16m1_poll;
586	}
587
588	s = &dev->subdevices[1];
589	/* di */
590	s->type = COMEDI_SUBD_DI;
591	s->subdev_flags = SDF_READABLE;
592	s->n_chan = 4;
593	s->maxdata = 1;
594	s->range_table = &range_digital;
595	s->insn_bits = das16m1_di_rbits;
596
597	s = &dev->subdevices[2];
598	/* do */
599	s->type = COMEDI_SUBD_DO;
600	s->subdev_flags = SDF_WRITABLE;
601	s->n_chan = 4;
602	s->maxdata = 1;
603	s->range_table = &range_digital;
604	s->insn_bits = das16m1_do_wbits;
605
606	s = &dev->subdevices[3];
607	/* 8255 */
608	ret = subdev_8255_init(dev, s, NULL, DAS16M1_82C55);
609	if (ret)
610		return ret;
611
612	/*  initialize digital output lines */
613	outb(0, dev->iobase + DAS16M1_DIO);
614
615	/* set the interrupt level */
616	devpriv->control_state = das16m1_irq_bits(dev->irq) << 4;
617	outb(devpriv->control_state, dev->iobase + DAS16M1_INTR_CONTROL);
618
619	return 0;
620}
621
622static void das16m1_detach(struct comedi_device *dev)
623{
624	struct das16m1_private_struct *devpriv = dev->private;
625
626	if (devpriv) {
627		if (devpriv->extra_iobase)
628			release_region(devpriv->extra_iobase, DAS16M1_SIZE2);
629		kfree(devpriv->counter);
630	}
631	comedi_legacy_detach(dev);
632}
633
634static struct comedi_driver das16m1_driver = {
635	.driver_name	= "das16m1",
636	.module		= THIS_MODULE,
637	.attach		= das16m1_attach,
638	.detach		= das16m1_detach,
639};
640module_comedi_driver(das16m1_driver);
641
642MODULE_AUTHOR("Comedi http://www.comedi.org");
643MODULE_DESCRIPTION("Comedi low-level driver");
644MODULE_LICENSE("GPL");
645