drivers/staging/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  */
  51 static 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
  68 static 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
 102 static 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
 127 static struct comedi_driver dac02_driver = {
 128         .driver_name    = "dac02",
 129         .module         = THIS_MODULE,
 130         .attach         = dac02_attach,
 131         .detach         = comedi_legacy_detach,
 132 };
 133 module_comedi_driver(dac02_driver);
 134
 135 MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
 136 MODULE_DESCRIPTION("Comedi driver for DAC02 compatible boards");
 137 MODULE_LICENSE("GPL");