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

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * pcmad.c
   4 * Hardware driver for Winsystems PCM-A/D12 and PCM-A/D16
   5 *
   6 * COMEDI - Linux Control and Measurement Device Interface
   7 * Copyright (C) 2000,2001 David A. Schleef <ds@schleef.org>
   8 */
   9
  10/*
  11 * Driver: pcmad
  12 * Description: Winsystems PCM-A/D12, PCM-A/D16
  13 * Devices: [Winsystems] PCM-A/D12 (pcmad12), PCM-A/D16 (pcmad16)
  14 * Author: ds
  15 * Status: untested
  16 *
  17 * This driver was written on a bet that I couldn't write a driver
  18 * in less than 2 hours.  I won the bet, but never got paid.  =(
  19 *
  20 * Configuration options:
  21 *   [0] - I/O port base
  22 *   [1] - IRQ (unused)
  23 *   [2] - Analog input reference (must match jumpers)
  24 *         0 = single-ended (16 channels)
  25 *         1 = differential (8 channels)
  26 *   [3] - Analog input encoding (must match jumpers)
  27 *         0 = straight binary (0-5V input range)
  28 *         1 = two's complement (+-10V input range)
  29 */
  30
  31#include <linux/module.h>
  32#include "../comedidev.h"
  33
  34#define PCMAD_STATUS            0
  35#define PCMAD_LSB               1
  36#define PCMAD_MSB               2
  37#define PCMAD_CONVERT           1
  38
  39struct pcmad_board_struct {
  40        const char *name;
  41        unsigned int ai_maxdata;
  42};
  43
  44static const struct pcmad_board_struct pcmad_boards[] = {
  45        {
  46                .name           = "pcmad12",
  47                .ai_maxdata     = 0x0fff,
  48        }, {
  49                .name           = "pcmad16",
  50                .ai_maxdata     = 0xffff,
  51        },
  52};
  53
  54static int pcmad_ai_eoc(struct comedi_device *dev,
  55                        struct comedi_subdevice *s,
  56                        struct comedi_insn *insn,
  57                        unsigned long context)
  58{
  59        unsigned int status;
  60
  61        status = inb(dev->iobase + PCMAD_STATUS);
  62        if ((status & 0x3) == 0x3)
  63                return 0;
  64        return -EBUSY;
  65}
  66
  67static int pcmad_ai_insn_read(struct comedi_device *dev,
  68                              struct comedi_subdevice *s,
  69                              struct comedi_insn *insn,
  70                              unsigned int *data)
  71{
  72        unsigned int chan = CR_CHAN(insn->chanspec);
  73        unsigned int range = CR_RANGE(insn->chanspec);
  74        unsigned int val;
  75        int ret;
  76        int i;
  77
  78        for (i = 0; i < insn->n; i++) {
  79                outb(chan, dev->iobase + PCMAD_CONVERT);
  80
  81                ret = comedi_timeout(dev, s, insn, pcmad_ai_eoc, 0);
  82                if (ret)
  83                        return ret;
  84
  85                val = inb(dev->iobase + PCMAD_LSB) |
  86                      (inb(dev->iobase + PCMAD_MSB) << 8);
  87
  88                /* data is shifted on the pcmad12, fix it */
  89                if (s->maxdata == 0x0fff)
  90                        val >>= 4;
  91
  92                if (comedi_range_is_bipolar(s, range)) {
  93                        /* munge the two's complement value */
  94                        val ^= ((s->maxdata + 1) >> 1);
  95                }
  96
  97                data[i] = val;
  98        }
  99
 100        return insn->n;
 101}
 102
 103static int pcmad_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 104{
 105        const struct pcmad_board_struct *board = dev->board_ptr;
 106        struct comedi_subdevice *s;
 107        int ret;
 108
 109        ret = comedi_request_region(dev, it->options[0], 0x04);
 110        if (ret)
 111                return ret;
 112
 113        ret = comedi_alloc_subdevices(dev, 1);
 114        if (ret)
 115                return ret;
 116
 117        s = &dev->subdevices[0];
 118        s->type         = COMEDI_SUBD_AI;
 119        if (it->options[1]) {
 120                /* 8 differential channels */
 121                s->subdev_flags = SDF_READABLE | AREF_DIFF;
 122                s->n_chan       = 8;
 123        } else {
 124                /* 16 single-ended channels */
 125                s->subdev_flags = SDF_READABLE | AREF_GROUND;
 126                s->n_chan       = 16;
 127        }
 128        s->len_chanlist = 1;
 129        s->maxdata      = board->ai_maxdata;
 130        s->range_table  = it->options[2] ? &range_bipolar10 : &range_unipolar5;
 131        s->insn_read    = pcmad_ai_insn_read;
 132
 133        return 0;
 134}
 135
 136static struct comedi_driver pcmad_driver = {
 137        .driver_name    = "pcmad",
 138        .module         = THIS_MODULE,
 139        .attach         = pcmad_attach,
 140        .detach         = comedi_legacy_detach,
 141        .board_name     = &pcmad_boards[0].name,
 142        .num_names      = ARRAY_SIZE(pcmad_boards),
 143        .offset         = sizeof(pcmad_boards[0]),
 144};
 145module_comedi_driver(pcmad_driver);
 146
 147MODULE_AUTHOR("Comedi https://www.comedi.org");
 148MODULE_DESCRIPTION("Comedi low-level driver");
 149MODULE_LICENSE("GPL");
 150