3 * Driver for Winsystems PC-104 based PCM-D/A-12 8-channel AO board.
5 * COMEDI - Linux Control and Measurement Device Interface
6 * Copyright (C) 2006 Calin A. Culianu <calin@ajvar.org>
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.
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.
21 * Description: A driver for the Winsystems PCM-D/A-12
22 * Devices: [Winsystems] PCM-D/A-12 (pcmda12)
23 * Author: Calin Culianu <calin@ajvar.org>
24 * Updated: Fri, 13 Jan 2006 12:01:01 -0500
27 * A driver for the relatively straightforward-to-program PCM-D/A-12.
28 * This board doesn't support commands, and the only way to set its
29 * analog output range is to jumper the board. As such,
30 * comedi_data_write() ignores the range value specified.
32 * The board uses 16 consecutive I/O addresses starting at the I/O port
33 * base address. Each address corresponds to the LSB then MSB of a
34 * particular channel from 0-7.
36 * Note that the board is not ISA-PNP capable and thus needs the I/O
37 * port comedi_config parameter.
39 * Note that passing a nonzero value as the second config option will
40 * enable "simultaneous xfer" mode for this board, in which AO writes
41 * will not take effect until a subsequent read of any AO channel. This
42 * is so that one can speed up programming by preloading all AO registers
43 * with values before simultaneously setting them to take effect with one
46 * Configuration Options:
47 * [0] - I/O port base address
48 * [1] - Do Simultaneous Xfer (see description)
51 #include <linux/module.h>
52 #include "../comedidev.h"
54 /* AI range is not configurable, it's set by jumpers on the board */
55 static const struct comedi_lrange pcmda12_ranges = {
63 struct pcmda12_private {
64 int simultaneous_xfer_mode;
67 static int pcmda12_ao_insn_write(struct comedi_device *dev,
68 struct comedi_subdevice *s,
69 struct comedi_insn *insn,
72 struct pcmda12_private *devpriv = dev->private;
73 unsigned int chan = CR_CHAN(insn->chanspec);
74 unsigned int val = s->readback[chan];
75 unsigned long ioreg = dev->iobase + (chan * 2);
78 for (i = 0; i < insn->n; ++i) {
80 outb(val & 0xff, ioreg);
81 outb((val >> 8) & 0xff, ioreg + 1);
84 * Initiate transfer if not in simultaneaous xfer
85 * mode by reading one of the AO registers.
87 if (!devpriv->simultaneous_xfer_mode)
90 s->readback[chan] = val;
95 static int pcmda12_ao_insn_read(struct comedi_device *dev,
96 struct comedi_subdevice *s,
97 struct comedi_insn *insn,
100 struct pcmda12_private *devpriv = dev->private;
103 * Initiate simultaneaous xfer mode by reading one of the
104 * AO registers. All analog outputs will then be updated.
106 if (devpriv->simultaneous_xfer_mode)
109 return comedi_readback_insn_read(dev, s, insn, data);
112 static void pcmda12_ao_reset(struct comedi_device *dev,
113 struct comedi_subdevice *s)
117 for (i = 0; i < s->n_chan; ++i) {
118 outb(0, dev->iobase + (i * 2));
119 outb(0, dev->iobase + (i * 2) + 1);
121 /* Initiate transfer by reading one of the AO registers. */
125 static int pcmda12_attach(struct comedi_device *dev,
126 struct comedi_devconfig *it)
128 struct pcmda12_private *devpriv;
129 struct comedi_subdevice *s;
132 ret = comedi_request_region(dev, it->options[0], 0x10);
136 devpriv = comedi_alloc_devpriv(dev, sizeof(*devpriv));
140 devpriv->simultaneous_xfer_mode = it->options[1];
142 ret = comedi_alloc_subdevices(dev, 1);
146 s = &dev->subdevices[0];
147 s->type = COMEDI_SUBD_AO;
148 s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
151 s->range_table = &pcmda12_ranges;
152 s->insn_write = pcmda12_ao_insn_write;
153 s->insn_read = pcmda12_ao_insn_read;
155 ret = comedi_alloc_subdev_readback(s);
159 pcmda12_ao_reset(dev, s);
164 static struct comedi_driver pcmda12_driver = {
165 .driver_name = "pcmda12",
166 .module = THIS_MODULE,
167 .attach = pcmda12_attach,
168 .detach = comedi_legacy_detach,
170 module_comedi_driver(pcmda12_driver);
172 MODULE_AUTHOR("Comedi http://www.comedi.org");
173 MODULE_DESCRIPTION("Comedi low-level driver");
174 MODULE_LICENSE("GPL");