pcmad.c revision 7114a28011f9d5f3d981731ad341177c21f9d948 
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
92static int __init driver_pcmad_init_module(void)
93{
94	return comedi_driver_register(&driver_pcmad);
95}
96
97static void __exit driver_pcmad_cleanup_module(void)
98{
99	comedi_driver_unregister(&driver_pcmad);
100}
101
102module_init(driver_pcmad_init_module);
103module_exit(driver_pcmad_cleanup_module);
104
105#define TIMEOUT	100
106
107static int pcmad_ai_insn_read(struct comedi_device *dev,
108			      struct comedi_subdevice *s,
109			      struct comedi_insn *insn, unsigned int *data)
110{
111	int i;
112	int chan;
113	int n;
114
115	chan = CR_CHAN(insn->chanspec);
116
117	for (n = 0; n < insn->n; n++) {
118		outb(chan, dev->iobase + PCMAD_CONVERT);
119
120		for (i = 0; i < TIMEOUT; i++) {
121			if ((inb(dev->iobase + PCMAD_STATUS) & 0x3) == 0x3)
122				break;
123		}
124		data[n] = inb(dev->iobase + PCMAD_LSB);
125		data[n] |= (inb(dev->iobase + PCMAD_MSB) << 8);
126
127		if (devpriv->twos_comp)
128			data[n] ^= (1 << (this_board->n_ai_bits - 1));
129	}
130
131	return n;
132}
133
134/*
135 * options:
136 * 0	i/o base
137 * 1	unused
138 * 2	0=single ended 1=differential
139 * 3	0=straight binary 1=two's comp
140 */
141static int pcmad_attach(struct comedi_device *dev, struct comedi_devconfig *it)
142{
143	int ret;
144	struct comedi_subdevice *s;
145	unsigned long iobase;
146
147	iobase = it->options[0];
148	printk(KERN_INFO "comedi%d: pcmad: 0x%04lx ", dev->minor, iobase);
149	if (!request_region(iobase, PCMAD_SIZE, "pcmad")) {
150		printk(KERN_CONT "I/O port conflict\n");
151		return -EIO;
152	}
153	printk(KERN_CONT "\n");
154	dev->iobase = iobase;
155
156	ret = alloc_subdevices(dev, 1);
157	if (ret < 0)
158		return ret;
159
160	ret = alloc_private(dev, sizeof(struct pcmad_priv_struct));
161	if (ret < 0)
162		return ret;
163
164	dev->board_name = this_board->name;
165
166	s = dev->subdevices + 0;
167	s->type = COMEDI_SUBD_AI;
168	s->subdev_flags = SDF_READABLE | AREF_GROUND;
169	s->n_chan = 16;		/* XXX */
170	s->len_chanlist = 1;
171	s->insn_read = pcmad_ai_insn_read;
172	s->maxdata = (1 << this_board->n_ai_bits) - 1;
173	s->range_table = &range_unknown;
174
175	return 0;
176}
177
178static int pcmad_detach(struct comedi_device *dev)
179{
180	printk(KERN_INFO "comedi%d: pcmad: remove\n", dev->minor);
181
182	if (dev->irq)
183		free_irq(dev->irq, dev);
184
185	if (dev->iobase)
186		release_region(dev->iobase, PCMAD_SIZE);
187
188	return 0;
189}
190
191MODULE_AUTHOR("Comedi http://www.comedi.org");
192MODULE_DESCRIPTION("Comedi low-level driver");
193MODULE_LICENSE("GPL");
194