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

   1/*
   2 * pcmad.c
   3 * Hardware driver for Winsystems PCM-A/D12 and PCM-A/D16
   4 *
   5 * COMEDI - Linux Control and Measurement Device Interface
   6 * Copyright (C) 2000,2001 David A. Schleef <ds@schleef.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: pcmad
  21 * Description: Winsystems PCM-A/D12, PCM-A/D16
  22 * Devices: [Winsystems] PCM-A/D12 (pcmad12), PCM-A/D16 (pcmad16)
  23 * Author: ds
  24 * Status: untested
  25 *
  26 * This driver was written on a bet that I couldn't write a driver
  27 * in less than 2 hours.  I won the bet, but never got paid.  =(
  28 *
  29 * Configuration options:
  30 *   [0] - I/O port base
  31 *   [1] - IRQ (unused)
  32 *   [2] - Analog input reference (must match jumpers)
  33 *         0 = single-ended (16 channels)
  34 *         1 = differential (8 channels)
  35 *   [3] - Analog input encoding (must match jumpers)
  36 *         0 = straight binary (0-5V input range)
  37 *         1 = two's complement (+-10V input range)
  38 */
  39
  40#include <linux/module.h>
  41#include "../comedidev.h"
  42
  43#define PCMAD_STATUS            0
  44#define PCMAD_LSB               1
  45#define PCMAD_MSB               2
  46#define PCMAD_CONVERT           1
  47
  48struct pcmad_board_struct {
  49        const char *name;
  50        unsigned int ai_maxdata;
  51};
  52
  53static const struct pcmad_board_struct pcmad_boards[] = {
  54        {
  55                .name           = "pcmad12",
  56                .ai_maxdata     = 0x0fff,
  57        }, {
  58                .name           = "pcmad16",
  59                .ai_maxdata     = 0xffff,
  60        },
  61};
  62
  63static int pcmad_ai_eoc(struct comedi_device *dev,
  64                        struct comedi_subdevice *s,
  65                        struct comedi_insn *insn,
  66                        unsigned long context)
  67{
  68        unsigned int status;
  69
  70        status = inb(dev->iobase + PCMAD_STATUS);
  71        if ((status & 0x3) == 0x3)
  72                return 0;
  73        return -EBUSY;
  74}
  75
  76static int pcmad_ai_insn_read(struct comedi_device *dev,
  77                              struct comedi_subdevice *s,
  78                              struct comedi_insn *insn,
  79                              unsigned int *data)
  80{
  81        unsigned int chan = CR_CHAN(insn->chanspec);
  82        unsigned int range = CR_RANGE(insn->chanspec);
  83        unsigned int val;
  84        int ret;
  85        int i;
  86
  87        for (i = 0; i < insn->n; i++) {
  88                outb(chan, dev->iobase + PCMAD_CONVERT);
  89
  90                ret = comedi_timeout(dev, s, insn, pcmad_ai_eoc, 0);
  91                if (ret)
  92                        return ret;
  93
  94                val = inb(dev->iobase + PCMAD_LSB) |
  95                      (inb(dev->iobase + PCMAD_MSB) << 8);
  96
  97                /* data is shifted on the pcmad12, fix it */
  98                if (s->maxdata == 0x0fff)
  99                        val >>= 4;
 100
 101                if (comedi_range_is_bipolar(s, range)) {
 102                        /* munge the two's complement value */
 103                        val ^= ((s->maxdata + 1) >> 1);
 104                }
 105
 106                data[i] = val;
 107        }
 108
 109        return insn->n;
 110}
 111
 112static int pcmad_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 113{
 114        const struct pcmad_board_struct *board = dev->board_ptr;
 115        struct comedi_subdevice *s;
 116        int ret;
 117
 118        ret = comedi_request_region(dev, it->options[0], 0x04);
 119        if (ret)
 120                return ret;
 121
 122        ret = comedi_alloc_subdevices(dev, 1);
 123        if (ret)
 124                return ret;
 125
 126        s = &dev->subdevices[0];
 127        s->type         = COMEDI_SUBD_AI;
 128        if (it->options[1]) {
 129                /* 8 differential channels */
 130                s->subdev_flags = SDF_READABLE | AREF_DIFF;
 131                s->n_chan       = 8;
 132        } else {
 133                /* 16 single-ended channels */
 134                s->subdev_flags = SDF_READABLE | AREF_GROUND;
 135                s->n_chan       = 16;
 136        }
 137        s->len_chanlist = 1;
 138        s->maxdata      = board->ai_maxdata;
 139        s->range_table  = it->options[2] ? &range_bipolar10 : &range_unipolar5;
 140        s->insn_read    = pcmad_ai_insn_read;
 141
 142        return 0;
 143}
 144
 145static struct comedi_driver pcmad_driver = {
 146        .driver_name    = "pcmad",
 147        .module         = THIS_MODULE,
 148        .attach         = pcmad_attach,
 149        .detach         = comedi_legacy_detach,
 150        .board_name     = &pcmad_boards[0].name,
 151        .num_names      = ARRAY_SIZE(pcmad_boards),
 152        .offset         = sizeof(pcmad_boards[0]),
 153};
 154module_comedi_driver(pcmad_driver);
 155
 156MODULE_AUTHOR("Comedi http://www.comedi.org");
 157MODULE_DESCRIPTION("Comedi low-level driver");
 158MODULE_LICENSE("GPL");
 159