LXR linux/drivers/staging/comedi/drivers/dac02.c

   1/*
   2 * dac02.c
   3 * Comedi driver for DAC02 compatible boards
   4 * Copyright (C) 2014 H Hartley Sweeten <hsweeten@visionengravers.com>
   5 *
   6 * Based on the poc driver
   7 * Copyright (C) 2000 Frank Mori Hess <fmhess@users.sourceforge.net>
   8 * Copyright (C) 2001 David A. Schleef <ds@schleef.org>
   9 *
  10 * COMEDI - Linux Control and Measurement Device Interface
  11 * Copyright (C) 1998 David A. Schleef <ds@schleef.org>
  12 *
  13 * This program is free software; you can redistribute it and/or modify
  14 * it under the terms of the GNU General Public License as published by
  15 * the Free Software Foundation; either version 2 of the License, or
  16 * (at your option) any later version.
  17 *
  18 * This program is distributed in the hope that it will be useful,
  19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 * GNU General Public License for more details.
  22 */
  23
  24/*
  25 * Driver: dac02
  26 * Description: Comedi driver for DAC02 compatible boards
  27 * Devices: [Keithley Metrabyte] DAC-02 (dac02)
  28 * Author: H Hartley Sweeten <hsweeten@visionengravers.com>
  29 * Updated: Tue, 11 Mar 2014 11:27:19 -0700
  30 * Status: unknown
  31 *
  32 * Configuration options:
  33 *      [0] - I/O port base
  34 */
  35
  36#include <linux/module.h>
  37
  38#include "../comedidev.h"
  39
  40/*
  41 * The output range is selected by jumpering pins on the I/O connector.
  42 *
  43 *          Range      Chan #   Jumper pins        Output
  44 *      -------------  ------  -------------  -----------------
  45 *         0 to 5V       0        21 to 22      24
  46 *                       1        15 to 16      18
  47 *         0 to 10V      0        20 to 22      24
  48 *                       1        14 to 16      18
  49 *          +/-5V        0        21 to 22      23
  50 *                       1        15 to 16      17
  51 *          +/-10V       0        20 to 22      23
  52 *                       1        14 to 16      17
  53 *        4 to 20mA      0        21 to 22      25
  54 *                       1        15 to 16      19
  55 *      AC reference     0      In on pin 22    24 (2-quadrant)
  56 *                              In on pin 22    23 (4-quadrant)
  57 *                       1      In on pin 16    18 (2-quadrant)
  58 *                              In on pin 16    17 (4-quadrant)
  59 */
  60static const struct comedi_lrange das02_ao_ranges = {
  61        6, {
  62                UNI_RANGE(5),
  63                UNI_RANGE(10),
  64                BIP_RANGE(5),
  65                BIP_RANGE(10),
  66                RANGE_mA(4, 20),
  67                RANGE_ext(0, 1)
  68        }
  69};
  70
  71/*
  72 * Register I/O map
  73 */
  74#define DAC02_AO_LSB(x)         (0x00 + ((x) * 2))
  75#define DAC02_AO_MSB(x)         (0x01 + ((x) * 2))
  76
  77static int dac02_ao_insn_write(struct comedi_device *dev,
  78                               struct comedi_subdevice *s,
  79                               struct comedi_insn *insn,
  80                               unsigned int *data)
  81{
  82        unsigned int chan = CR_CHAN(insn->chanspec);
  83        unsigned int range = CR_RANGE(insn->chanspec);
  84        unsigned int val;
  85        int i;
  86
  87        for (i = 0; i < insn->n; i++) {
  88                val = data[i];
  89
  90                s->readback[chan] = val;
  91
  92                /*
  93                 * Unipolar outputs are true binary encoding.
  94                 * Bipolar outputs are complementary offset binary
  95                 * (that is, 0 = +full scale, maxdata = -full scale).
  96                 */
  97                if (comedi_range_is_bipolar(s, range))
  98                        val = s->maxdata - val;
  99
 100                /*
 101                 * DACs are double-buffered.
 102                 * Write LSB then MSB to latch output.
 103                 */
 104                outb((val << 4) & 0xf0, dev->iobase + DAC02_AO_LSB(chan));
 105                outb((val >> 4) & 0xff, dev->iobase + DAC02_AO_MSB(chan));
 106        }
 107
 108        return insn->n;
 109}
 110
 111static int dac02_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 112{
 113        struct comedi_subdevice *s;
 114        int ret;
 115
 116        ret = comedi_request_region(dev, it->options[0], 0x08);
 117        if (ret)
 118                return ret;
 119
 120        ret = comedi_alloc_subdevices(dev, 1);
 121        if (ret)
 122                return ret;
 123
 124        /* Analog Output subdevice */
 125        s = &dev->subdevices[0];
 126        s->type         = COMEDI_SUBD_AO;
 127        s->subdev_flags = SDF_WRITABLE;
 128        s->n_chan       = 2;
 129        s->maxdata      = 0x0fff;
 130        s->range_table  = &das02_ao_ranges;
 131        s->insn_write   = dac02_ao_insn_write;
 132
 133        return comedi_alloc_subdev_readback(s);
 134}
 135
 136static struct comedi_driver dac02_driver = {
 137        .driver_name    = "dac02",
 138        .module         = THIS_MODULE,
 139        .attach         = dac02_attach,
 140        .detach         = comedi_legacy_detach,
 141};
 142module_comedi_driver(dac02_driver);
 143
 144MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
 145MODULE_DESCRIPTION("Comedi driver for DAC02 compatible boards");
 146MODULE_LICENSE("GPL");
 147