pcmad.c revision 58e732ee57eae8c3c3c550d1fa2f3b870ec2f13b 
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 "../comedidev.h"
45
46#include <linux/ioport.h>
47
48#define PCMAD_SIZE		4
49
50#define PCMAD_STATUS		0
51#define PCMAD_LSB		1
52#define PCMAD_MSB		2
53#define PCMAD_CONVERT		1
54
55struct pcmad_board_struct {
56	const char *name;
57	int n_ai_bits;
58};
59static const struct pcmad_board_struct pcmad_boards[] = {
60	{
61	      name:	"pcmad12",
62	      n_ai_bits:12,
63		},
64	{
65	      name:	"pcmad16",
66	      n_ai_bits:16,
67		},
68};
69
70#define this_board ((const struct pcmad_board_struct *)(dev->board_ptr))
71#define n_pcmad_boards (sizeof(pcmad_boards)/sizeof(pcmad_boards[0]))
72
73struct pcmad_priv_struct {
74	int differential;
75	int twos_comp;
76};
77#define devpriv ((struct pcmad_priv_struct *)dev->private)
78
79static int pcmad_attach(comedi_device * dev, comedi_devconfig * it);
80static int pcmad_detach(comedi_device * dev);
81static comedi_driver driver_pcmad = {
82      driver_name:"pcmad",
83      module:THIS_MODULE,
84      attach:pcmad_attach,
85      detach:pcmad_detach,
86      board_name:&pcmad_boards[0].name,
87      num_names:n_pcmad_boards,
88      offset:sizeof(pcmad_boards[0]),
89};
90
91COMEDI_INITCLEANUP(driver_pcmad);
92
93#define TIMEOUT	100
94
95static int pcmad_ai_insn_read(comedi_device * dev, comedi_subdevice * s,
96	comedi_insn * insn, lsampl_t * data)
97{
98	int i;
99	int chan;
100	int n;
101
102	chan = CR_CHAN(insn->chanspec);
103
104	for (n = 0; n < insn->n; n++) {
105		outb(chan, dev->iobase + PCMAD_CONVERT);
106
107		for (i = 0; i < TIMEOUT; i++) {
108			if ((inb(dev->iobase + PCMAD_STATUS) & 0x3) == 0x3)
109				break;
110		}
111		data[n] = inb(dev->iobase + PCMAD_LSB);
112		data[n] |= (inb(dev->iobase + PCMAD_MSB) << 8);
113
114		if (devpriv->twos_comp) {
115			data[n] ^= (1 << (this_board->n_ai_bits - 1));
116		}
117	}
118
119	return n;
120}
121
122/*
123 * options:
124 * 0	i/o base
125 * 1	unused
126 * 2	0=single ended 1=differential
127 * 3	0=straight binary 1=two's comp
128 */
129static int pcmad_attach(comedi_device * dev, comedi_devconfig * it)
130{
131	int ret;
132	comedi_subdevice *s;
133	unsigned long iobase;
134
135	iobase = it->options[0];
136	printk("comedi%d: pcmad: 0x%04lx ", dev->minor, iobase);
137	if (!request_region(iobase, PCMAD_SIZE, "pcmad")) {
138		printk("I/O port conflict\n");
139		return -EIO;
140	}
141	dev->iobase = iobase;
142
143	if ((ret = alloc_subdevices(dev, 1)) < 0)
144		return ret;
145	if ((ret = alloc_private(dev, sizeof(struct pcmad_priv_struct))) < 0)
146		return ret;
147
148	dev->board_name = this_board->name;
149
150	s = dev->subdevices + 0;
151	s->type = COMEDI_SUBD_AI;
152	s->subdev_flags = SDF_READABLE | AREF_GROUND;
153	s->n_chan = 16;		/* XXX */
154	s->len_chanlist = 1;
155	s->insn_read = pcmad_ai_insn_read;
156	s->maxdata = (1 << this_board->n_ai_bits) - 1;
157	s->range_table = &range_unknown;
158
159	return 0;
160}
161
162static int pcmad_detach(comedi_device * dev)
163{
164	printk("comedi%d: pcmad: remove\n", dev->minor);
165
166	if (dev->irq) {
167		free_irq(dev->irq, dev);
168	}
169	if (dev->iobase)
170		release_region(dev->iobase, PCMAD_SIZE);
171
172	return 0;
173}
174