LXR linux/drivers/staging/comedi/drivers/pcmda12.c

   1/*
   2 * pcmda12.c
   3 * Driver for Winsystems PC-104 based PCM-D/A-12 8-channel AO board.
   4 *
   5 * COMEDI - Linux Control and Measurement Device Interface
   6 * Copyright (C) 2006 Calin A. Culianu <calin@ajvar.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
  19/*
  20 * Driver: pcmda12
  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
  25 * Status: works
  26 *
  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.
  31 *
  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.
  35 *
  36 * Note that the board is not ISA-PNP capable and thus needs the I/O
  37 * port comedi_config parameter.
  38 *
  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
  44 * read command.
  45 *
  46 * Configuration Options:
  47 *   [0] - I/O port base address
  48 *   [1] - Do Simultaneous Xfer (see description)
  49 */
  50
  51#include <linux/module.h>
  52#include "../comedidev.h"
  53
  54/* AI range is not configurable, it's set by jumpers on the board */
  55static const struct comedi_lrange pcmda12_ranges = {
  56        3, {
  57                UNI_RANGE(5),
  58                UNI_RANGE(10),
  59                BIP_RANGE(5)
  60        }
  61};
  62
  63struct pcmda12_private {
  64        int simultaneous_xfer_mode;
  65};
  66
  67static int pcmda12_ao_insn_write(struct comedi_device *dev,
  68                                 struct comedi_subdevice *s,
  69                                 struct comedi_insn *insn,
  70                                 unsigned int *data)
  71{
  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);
  76        int i;
  77
  78        for (i = 0; i < insn->n; ++i) {
  79                val = data[i];
  80                outb(val & 0xff, ioreg);
  81                outb((val >> 8) & 0xff, ioreg + 1);
  82
  83                /*
  84                 * Initiate transfer if not in simultaneaous xfer
  85                 * mode by reading one of the AO registers.
  86                 */
  87                if (!devpriv->simultaneous_xfer_mode)
  88                        inb(ioreg);
  89        }
  90        s->readback[chan] = val;
  91
  92        return insn->n;
  93}
  94
  95static int pcmda12_ao_insn_read(struct comedi_device *dev,
  96                                struct comedi_subdevice *s,
  97                                struct comedi_insn *insn,
  98                                unsigned int *data)
  99{
 100        struct pcmda12_private *devpriv = dev->private;
 101
 102        /*
 103         * Initiate simultaneaous xfer mode by reading one of the
 104         * AO registers. All analog outputs will then be updated.
 105         */
 106        if (devpriv->simultaneous_xfer_mode)
 107                inb(dev->iobase);
 108
 109        return comedi_readback_insn_read(dev, s, insn, data);
 110}
 111
 112static void pcmda12_ao_reset(struct comedi_device *dev,
 113                             struct comedi_subdevice *s)
 114{
 115        int i;
 116
 117        for (i = 0; i < s->n_chan; ++i) {
 118                outb(0, dev->iobase + (i * 2));
 119                outb(0, dev->iobase + (i * 2) + 1);
 120        }
 121        /* Initiate transfer by reading one of the AO registers. */
 122        inb(dev->iobase);
 123}
 124
 125static int pcmda12_attach(struct comedi_device *dev,
 126                          struct comedi_devconfig *it)
 127{
 128        struct pcmda12_private *devpriv;
 129        struct comedi_subdevice *s;
 130        int ret;
 131
 132        ret = comedi_request_region(dev, it->options[0], 0x10);
 133        if (ret)
 134                return ret;
 135
 136        devpriv = comedi_alloc_devpriv(dev, sizeof(*devpriv));
 137        if (!devpriv)
 138                return -ENOMEM;
 139
 140        devpriv->simultaneous_xfer_mode = it->options[1];
 141
 142        ret = comedi_alloc_subdevices(dev, 1);
 143        if (ret)
 144                return ret;
 145
 146        s = &dev->subdevices[0];
 147        s->type         = COMEDI_SUBD_AO;
 148        s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
 149        s->n_chan       = 8;
 150        s->maxdata      = 0x0fff;
 151        s->range_table  = &pcmda12_ranges;
 152        s->insn_write   = pcmda12_ao_insn_write;
 153        s->insn_read    = pcmda12_ao_insn_read;
 154
 155        ret = comedi_alloc_subdev_readback(s);
 156        if (ret)
 157                return ret;
 158
 159        pcmda12_ao_reset(dev, s);
 160
 161        return 0;
 162}
 163
 164static struct comedi_driver pcmda12_driver = {
 165        .driver_name    = "pcmda12",
 166        .module         = THIS_MODULE,
 167        .attach         = pcmda12_attach,
 168        .detach         = comedi_legacy_detach,
 169};
 170module_comedi_driver(pcmda12_driver);
 171
 172MODULE_AUTHOR("Comedi http://www.comedi.org");
 173MODULE_DESCRIPTION("Comedi low-level driver");
 174MODULE_LICENSE("GPL");
 175