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

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * dac02.c
   4 * Comedi driver for DAC02 compatible boards
   5 * Copyright (C) 2014 H Hartley Sweeten <hsweeten@visionengravers.com>
   6 *
   7 * Based on the poc driver
   8 * Copyright (C) 2000 Frank Mori Hess <fmhess@users.sourceforge.net>
   9 * Copyright (C) 2001 David A. Schleef <ds@schleef.org>
  10 *
  11 * COMEDI - Linux Control and Measurement Device Interface
  12 * Copyright (C) 1998 David A. Schleef <ds@schleef.org>
  13 */
  14
  15/*
  16 * Driver: dac02
  17 * Description: Comedi driver for DAC02 compatible boards
  18 * Devices: [Keithley Metrabyte] DAC-02 (dac02)
  19 * Author: H Hartley Sweeten <hsweeten@visionengravers.com>
  20 * Updated: Tue, 11 Mar 2014 11:27:19 -0700
  21 * Status: unknown
  22 *
  23 * Configuration options:
  24 *      [0] - I/O port base
  25 */
  26
  27#include <linux/module.h>
  28
  29#include "../comedidev.h"
  30
  31/*
  32 * The output range is selected by jumpering pins on the I/O connector.
  33 *
  34 *          Range      Chan #   Jumper pins        Output
  35 *      -------------  ------  -------------  -----------------
  36 *         0 to 5V       0        21 to 22      24
  37 *                       1        15 to 16      18
  38 *         0 to 10V      0        20 to 22      24
  39 *                       1        14 to 16      18
  40 *          +/-5V        0        21 to 22      23
  41 *                       1        15 to 16      17
  42 *          +/-10V       0        20 to 22      23
  43 *                       1        14 to 16      17
  44 *        4 to 20mA      0        21 to 22      25
  45 *                       1        15 to 16      19
  46 *      AC reference     0      In on pin 22    24 (2-quadrant)
  47 *                              In on pin 22    23 (4-quadrant)
  48 *                       1      In on pin 16    18 (2-quadrant)
  49 *                              In on pin 16    17 (4-quadrant)
  50 */
  51static const struct comedi_lrange das02_ao_ranges = {
  52        6, {
  53                UNI_RANGE(5),
  54                UNI_RANGE(10),
  55                BIP_RANGE(5),
  56                BIP_RANGE(10),
  57                RANGE_mA(4, 20),
  58                RANGE_ext(0, 1)
  59        }
  60};
  61
  62/*
  63 * Register I/O map
  64 */
  65#define DAC02_AO_LSB(x)         (0x00 + ((x) * 2))
  66#define DAC02_AO_MSB(x)         (0x01 + ((x) * 2))
  67
  68static int dac02_ao_insn_write(struct comedi_device *dev,
  69                               struct comedi_subdevice *s,
  70                               struct comedi_insn *insn,
  71                               unsigned int *data)
  72{
  73        unsigned int chan = CR_CHAN(insn->chanspec);
  74        unsigned int range = CR_RANGE(insn->chanspec);
  75        unsigned int val;
  76        int i;
  77
  78        for (i = 0; i < insn->n; i++) {
  79                val = data[i];
  80
  81                s->readback[chan] = val;
  82
  83                /*
  84                 * Unipolar outputs are true binary encoding.
  85                 * Bipolar outputs are complementary offset binary
  86                 * (that is, 0 = +full scale, maxdata = -full scale).
  87                 */
  88                if (comedi_range_is_bipolar(s, range))
  89                        val = s->maxdata - val;
  90
  91                /*
  92                 * DACs are double-buffered.
  93                 * Write LSB then MSB to latch output.
  94                 */
  95                outb((val << 4) & 0xf0, dev->iobase + DAC02_AO_LSB(chan));
  96                outb((val >> 4) & 0xff, dev->iobase + DAC02_AO_MSB(chan));
  97        }
  98
  99        return insn->n;
 100}
 101
 102static int dac02_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 103{
 104        struct comedi_subdevice *s;
 105        int ret;
 106
 107        ret = comedi_request_region(dev, it->options[0], 0x08);
 108        if (ret)
 109                return ret;
 110
 111        ret = comedi_alloc_subdevices(dev, 1);
 112        if (ret)
 113                return ret;
 114
 115        /* Analog Output subdevice */
 116        s = &dev->subdevices[0];
 117        s->type         = COMEDI_SUBD_AO;
 118        s->subdev_flags = SDF_WRITABLE;
 119        s->n_chan       = 2;
 120        s->maxdata      = 0x0fff;
 121        s->range_table  = &das02_ao_ranges;
 122        s->insn_write   = dac02_ao_insn_write;
 123
 124        return comedi_alloc_subdev_readback(s);
 125}
 126
 127static struct comedi_driver dac02_driver = {
 128        .driver_name    = "dac02",
 129        .module         = THIS_MODULE,
 130        .attach         = dac02_attach,
 131        .detach         = comedi_legacy_detach,
 132};
 133module_comedi_driver(dac02_driver);
 134
 135MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
 136MODULE_DESCRIPTION("Comedi driver for DAC02 compatible boards");
 137MODULE_LICENSE("GPL");
 138