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
  48 struct pcmad_board_struct {
  49         const char *name;
  50         unsigned int ai_maxdata;
  51 };
  52
  53 static 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
  63 static 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
  76 static 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
 112 static 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
 145 static 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 };
 154 module_comedi_driver(pcmad_driver);
 155
 156 MODULE_AUTHOR("Comedi http://www.comedi.org");
 157 MODULE_DESCRIPTION("Comedi low-level driver");
 158 MODULE_LICENSE("GPL");