pcmad.c revision 90f703d30dd3e0c16ff80f35e34e511385a05ad5 
1/*
2    comedi/drivers/pcmad.c
3    Hardware driver for Winsystems PCM-A/D12 and PCM-A/D16
4
5    COMEDI - Linux Control and Measurement Device Interface
6    Copyright (C) 2000,2001 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    You should have received a copy of the GNU General Public License
19    along with this program; if not, write to the Free Software
20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21
22*/
23/*
24Driver: pcmad
25Description: Winsystems PCM-A/D12, PCM-A/D16
26Author: ds
27Devices: [Winsystems] PCM-A/D12 (pcmad12), PCM-A/D16 (pcmad16)
28Status: untested
29
30This driver was written on a bet that I couldn't write a driver
31in less than 2 hours.  I won the bet, but never got paid.  =(
32
33Configuration options:
34  [0] - I/O port base
35  [1] - unused
36  [2] - Analog input reference
37	0 = single ended
38	1 = differential
39  [3] - Analog input encoding (must match jumpers)
40	0 = straight binary
41	1 = two's complement
42*/
43
44#include <linux/interrupt.h>
45#include "../comedidev.h"
46
47#include <linux/ioport.h>
48
49#define PCMAD_SIZE		4
50
51#define PCMAD_STATUS		0
52#define PCMAD_LSB		1
53#define PCMAD_MSB		2
54#define PCMAD_CONVERT		1
55
56struct pcmad_board_struct {
57	const char *name;
58	int n_ai_bits;
59};
60static const struct pcmad_board_struct pcmad_boards[] = {
61	{
62	 .name = "pcmad12",
63	 .n_ai_bits = 12,
64	 },
65	{
66	 .name = "pcmad16",
67	 .n_ai_bits = 16,
68	 },
69};
70
71#define this_board ((const struct pcmad_board_struct *)(dev->board_ptr))
72#define n_pcmad_boards ARRAY_SIZE(pcmad_boards)
73
74struct pcmad_priv_struct {
75	int differential;
76	int twos_comp;
77};
78#define devpriv ((struct pcmad_priv_struct *)dev->private)
79
80static int pcmad_attach(struct comedi_device *dev, struct comedi_devconfig *it);
81static int pcmad_detach(struct comedi_device *dev);
82static struct comedi_driver driver_pcmad = {
83	.driver_name = "pcmad",
84	.module = THIS_MODULE,
85	.attach = pcmad_attach,
86	.detach = pcmad_detach,
87	.board_name = &pcmad_boards[0].name,
88	.num_names = n_pcmad_boards,
89	.offset = sizeof(pcmad_boards[0]),
90};
91
92COMEDI_INITCLEANUP(driver_pcmad);
93
94#define TIMEOUT	100
95
96static int pcmad_ai_insn_read(struct comedi_device *dev,
97			      struct comedi_subdevice *s,
98			      struct comedi_insn *insn, unsigned int *data)
99{
100	int i;
101	int chan;
102	int n;
103
104	chan = CR_CHAN(insn->chanspec);
105
106	for (n = 0; n < insn->n; n++) {
107		outb(chan, dev->iobase + PCMAD_CONVERT);
108
109		for (i = 0; i < TIMEOUT; i++) {
110			if ((inb(dev->iobase + PCMAD_STATUS) & 0x3) == 0x3)
111				break;
112		}
113		data[n] = inb(dev->iobase + PCMAD_LSB);
114		data[n] |= (inb(dev->iobase + PCMAD_MSB) << 8);
115
116		if (devpriv->twos_comp)
117			data[n] ^= (1 << (this_board->n_ai_bits - 1));
118	}
119
120	return n;
121}
122
123/*
124 * options:
125 * 0	i/o base
126 * 1	unused
127 * 2	0=single ended 1=differential
128 * 3	0=straight binary 1=two's comp
129 */
130static int pcmad_attach(struct comedi_device *dev, struct comedi_devconfig *it)
131{
132	int ret;
133	struct comedi_subdevice *s;
134	unsigned long iobase;
135
136	iobase = it->options[0];
137	printk(KERN_INFO "comedi%d: pcmad: 0x%04lx ", dev->minor, iobase);
138	if (!request_region(iobase, PCMAD_SIZE, "pcmad")) {
139		printk(KERN_CONT "I/O port conflict\n");
140		return -EIO;
141	}
142	printk(KERN_CONT "\n");
143	dev->iobase = iobase;
144
145	ret = alloc_subdevices(dev, 1);
146	if (ret < 0)
147		return ret;
148
149	ret = alloc_private(dev, sizeof(struct pcmad_priv_struct));
150	if (ret < 0)
151		return ret;
152
153	dev->board_name = this_board->name;
154
155	s = dev->subdevices + 0;
156	s->type = COMEDI_SUBD_AI;
157	s->subdev_flags = SDF_READABLE | AREF_GROUND;
158	s->n_chan = 16;		/* XXX */
159	s->len_chanlist = 1;
160	s->insn_read = pcmad_ai_insn_read;
161	s->maxdata = (1 << this_board->n_ai_bits) - 1;
162	s->range_table = &range_unknown;
163
164	return 0;
165}
166
167static int pcmad_detach(struct comedi_device *dev)
168{
169	printk(KERN_INFO "comedi%d: pcmad: remove\n", dev->minor);
170
171	if (dev->irq)
172		free_irq(dev->irq, dev);
173
174	if (dev->iobase)
175		release_region(dev->iobase, PCMAD_SIZE);
176
177	return 0;
178}
179
180MODULE_AUTHOR("Comedi http://www.comedi.org");
181MODULE_DESCRIPTION("Comedi low-level driver");
182MODULE_LICENSE("GPL");
183