dt2817.c revision 641f064e5df6fb3aaeb6256031a153a5efb16ca6 
1/*
2    comedi/drivers/dt2817.c
3    Hardware driver for Data Translation DT2817
4
5    COMEDI - Linux Control and Measurement Device Interface
6    Copyright (C) 1998 David A. Schleef <ds@schleef.org>
7
8    This program is free software; you can redistribute it and/or modify
9    it under the terms of the GNU General Public License as published by
10    the Free Software Foundation; either version 2 of the License, or
11    (at your option) any later version.
12
13    This program is distributed in the hope that it will be useful,
14    but WITHOUT ANY WARRANTY; without even the implied warranty of
15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16    GNU General Public License for more details.
17*/
18/*
19Driver: dt2817
20Description: Data Translation DT2817
21Author: ds
22Status: complete
23Devices: [Data Translation] DT2817 (dt2817)
24
25A very simple digital I/O card.  Four banks of 8 lines, each bank
26is configurable for input or output.  One wonders why it takes a
2750 page manual to describe this thing.
28
29The driver (which, btw, is much less than 50 pages) has 1 subdevice
30with 32 channels, configurable in groups of 8.
31
32Configuration options:
33  [0] - I/O port base base address
34*/
35
36#include "../comedidev.h"
37
38#include <linux/ioport.h>
39
40#define DT2817_SIZE 5
41
42#define DT2817_CR 0
43#define DT2817_DATA 1
44
45static int dt2817_dio_insn_config(struct comedi_device *dev,
46				  struct comedi_subdevice *s,
47				  struct comedi_insn *insn, unsigned int *data)
48{
49	int mask;
50	int chan;
51	int oe = 0;
52
53	if (insn->n != 1)
54		return -EINVAL;
55
56	chan = CR_CHAN(insn->chanspec);
57	if (chan < 8)
58		mask = 0xff;
59	else if (chan < 16)
60		mask = 0xff00;
61	else if (chan < 24)
62		mask = 0xff0000;
63	else
64		mask = 0xff000000;
65	if (data[0])
66		s->io_bits |= mask;
67	else
68		s->io_bits &= ~mask;
69
70	if (s->io_bits & 0x000000ff)
71		oe |= 0x1;
72	if (s->io_bits & 0x0000ff00)
73		oe |= 0x2;
74	if (s->io_bits & 0x00ff0000)
75		oe |= 0x4;
76	if (s->io_bits & 0xff000000)
77		oe |= 0x8;
78
79	outb(oe, dev->iobase + DT2817_CR);
80
81	return 1;
82}
83
84static int dt2817_dio_insn_bits(struct comedi_device *dev,
85				struct comedi_subdevice *s,
86				struct comedi_insn *insn, unsigned int *data)
87{
88	unsigned int changed;
89
90	/* It's questionable whether it is more important in
91	 * a driver like this to be deterministic or fast.
92	 * We choose fast. */
93
94	if (data[0]) {
95		changed = s->state;
96		s->state &= ~data[0];
97		s->state |= (data[0] & data[1]);
98		changed ^= s->state;
99		changed &= s->io_bits;
100		if (changed & 0x000000ff)
101			outb(s->state & 0xff, dev->iobase + DT2817_DATA + 0);
102		if (changed & 0x0000ff00)
103			outb((s->state >> 8) & 0xff,
104			     dev->iobase + DT2817_DATA + 1);
105		if (changed & 0x00ff0000)
106			outb((s->state >> 16) & 0xff,
107			     dev->iobase + DT2817_DATA + 2);
108		if (changed & 0xff000000)
109			outb((s->state >> 24) & 0xff,
110			     dev->iobase + DT2817_DATA + 3);
111	}
112	data[1] = inb(dev->iobase + DT2817_DATA + 0);
113	data[1] |= (inb(dev->iobase + DT2817_DATA + 1) << 8);
114	data[1] |= (inb(dev->iobase + DT2817_DATA + 2) << 16);
115	data[1] |= (inb(dev->iobase + DT2817_DATA + 3) << 24);
116
117	return insn->n;
118}
119
120static int dt2817_attach(struct comedi_device *dev, struct comedi_devconfig *it)
121{
122	int ret;
123	struct comedi_subdevice *s;
124
125	ret = comedi_request_region(dev, it->options[0], DT2817_SIZE);
126	if (ret)
127		return ret;
128
129	ret = comedi_alloc_subdevices(dev, 1);
130	if (ret)
131		return ret;
132
133	s = &dev->subdevices[0];
134
135	s->n_chan = 32;
136	s->type = COMEDI_SUBD_DIO;
137	s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
138	s->range_table = &range_digital;
139	s->maxdata = 1;
140	s->insn_bits = dt2817_dio_insn_bits;
141	s->insn_config = dt2817_dio_insn_config;
142
143	s->state = 0;
144	outb(0, dev->iobase + DT2817_CR);
145
146	return 0;
147}
148
149static struct comedi_driver dt2817_driver = {
150	.driver_name	= "dt2817",
151	.module		= THIS_MODULE,
152	.attach		= dt2817_attach,
153	.detach		= comedi_legacy_detach,
154};
155module_comedi_driver(dt2817_driver);
156
157MODULE_AUTHOR("Comedi http://www.comedi.org");
158MODULE_DESCRIPTION("Comedi low-level driver");
159MODULE_LICENSE("GPL");
160