drivers/staging/comedi/drivers/pcmad.c

   1 /*
   2     comedi/drivers/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     You should have received a copy of the GNU General Public License
  19     along with this program; if not, write to the Free Software
  20     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21
  22 */
  23 /*
  24 Driver: pcmad
  25 Description: Winsystems PCM-A/D12, PCM-A/D16
  26 Author: ds
  27 Devices: [Winsystems] PCM-A/D12 (pcmad12), PCM-A/D16 (pcmad16)
  28 Status: untested
  29
  30 This driver was written on a bet that I couldn't write a driver
  31 in less than 2 hours.  I won the bet, but never got paid.  =(
  32
  33 Configuration options:
  34   [0] - I/O port base
  35   [1] - unused
  36   [2] - Analog input reference
  37           0 = single ended
  38           1 = differential
  39   [3] - Analog input encoding (must match jumpers)
  40           0 = straight binary
  41           1 = two's complement
  42 */
  43
  44 #include <linux/interrupt.h>
  45 #include "../comedidev.h"
  46
  47 #include <linux/ioport.h>
  48
  49 #define PCMAD_SIZE              4
  50
  51 #define PCMAD_STATUS            0
  52 #define PCMAD_LSB               1
  53 #define PCMAD_MSB               2
  54 #define PCMAD_CONVERT           1
  55
  56 struct pcmad_board_struct {
  57         const char *name;
  58         int n_ai_bits;
  59 };
  60 static const struct pcmad_board_struct pcmad_boards[] = {
  61         {
  62         .name = "pcmad12",
  63         .n_ai_bits = 12,
  64                 },
  65         {
  66         .name = "pcmad16",
  67         .n_ai_bits = 16,
  68                 },
  69 };
  70
  71 #define this_board ((const struct pcmad_board_struct *)(dev->board_ptr))
  72 #define n_pcmad_boards (sizeof(pcmad_boards)/sizeof(pcmad_boards[0]))
  73
  74 struct pcmad_priv_struct {
  75         int differential;
  76         int twos_comp;
  77 };
  78 #define devpriv ((struct pcmad_priv_struct *)dev->private)
  79
  80 static int pcmad_attach(struct comedi_device *dev, struct comedi_devconfig *it);
  81 static int pcmad_detach(struct comedi_device *dev);
  82 static struct comedi_driver driver_pcmad = {
  83         .driver_name = "pcmad",
  84         .module = THIS_MODULE,
  85         .attach = pcmad_attach,
  86         .detach = pcmad_detach,
  87         .board_name = &pcmad_boards[0].name,
  88         .num_names = n_pcmad_boards,
  89         .offset = sizeof(pcmad_boards[0]),
  90 };
  91
  92 COMEDI_INITCLEANUP(driver_pcmad);
  93
  94 #define TIMEOUT 100
  95
  96 static int pcmad_ai_insn_read(struct comedi_device *dev, struct comedi_subdevice *s,
  97         struct comedi_insn *insn, unsigned int *data)
  98 {
  99         int i;
 100         int chan;
 101         int n;
 102
 103         chan = CR_CHAN(insn->chanspec);
 104
 105         for (n = 0; n < insn->n; n++) {
 106                 outb(chan, dev->iobase + PCMAD_CONVERT);
 107
 108                 for (i = 0; i < TIMEOUT; i++) {
 109                         if ((inb(dev->iobase + PCMAD_STATUS) & 0x3) == 0x3)
 110                                 break;
 111                 }
 112                 data[n] = inb(dev->iobase + PCMAD_LSB);
 113                 data[n] |= (inb(dev->iobase + PCMAD_MSB) << 8);
 114
 115                 if (devpriv->twos_comp) {
 116                         data[n] ^= (1 << (this_board->n_ai_bits - 1));
 117                 }
 118         }
 119
 120         return n;
 121 }
 122
 123 /*
 124  * options:
 125  * 0    i/o base
 126  * 1    unused
 127  * 2    0=single ended 1=differential
 128  * 3    0=straight binary 1=two's comp
 129  */
 130 static int pcmad_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 131 {
 132         int ret;
 133         struct comedi_subdevice *s;
 134         unsigned long iobase;
 135
 136         iobase = it->options[0];
 137         printk("comedi%d: pcmad: 0x%04lx ", dev->minor, iobase);
 138         if (!request_region(iobase, PCMAD_SIZE, "pcmad")) {
 139                 printk("I/O port conflict\n");
 140                 return -EIO;
 141         }
 142         dev->iobase = iobase;
 143
 144         ret = alloc_subdevices(dev, 1);
 145         if (ret < 0)
 146                 return ret;
 147
 148         ret = alloc_private(dev, sizeof(struct pcmad_priv_struct));
 149         if (ret < 0)
 150                 return ret;
 151
 152         dev->board_name = this_board->name;
 153
 154         s = dev->subdevices + 0;
 155         s->type = COMEDI_SUBD_AI;
 156         s->subdev_flags = SDF_READABLE | AREF_GROUND;
 157         s->n_chan = 16;         /* XXX */
 158         s->len_chanlist = 1;
 159         s->insn_read = pcmad_ai_insn_read;
 160         s->maxdata = (1 << this_board->n_ai_bits) - 1;
 161         s->range_table = &range_unknown;
 162
 163         return 0;
 164 }
 165
 166 static int pcmad_detach(struct comedi_device *dev)
 167 {
 168         printk("comedi%d: pcmad: remove\n", dev->minor);
 169
 170         if (dev->irq) {
 171                 free_irq(dev->irq, dev);
 172         }
 173         if (dev->iobase)
 174                 release_region(dev->iobase, PCMAD_SIZE);
 175
 176         return 0;
 177 }