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 ARRAY_SIZE(pcmad_boards)
  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 static int __init driver_pcmad_init_module(void)
  93 {
  94         return comedi_driver_register(&driver_pcmad);
  95 }
  96
  97 static void __exit driver_pcmad_cleanup_module(void)
  98 {
  99         comedi_driver_unregister(&driver_pcmad);
 100 }
 101
 102 module_init(driver_pcmad_init_module);
 103 module_exit(driver_pcmad_cleanup_module);
 104
 105 #define TIMEOUT 100
 106
 107 static int pcmad_ai_insn_read(struct comedi_device *dev,
 108                               struct comedi_subdevice *s,
 109                               struct comedi_insn *insn, unsigned int *data)
 110 {
 111         int i;
 112         int chan;
 113         int n;
 114
 115         chan = CR_CHAN(insn->chanspec);
 116
 117         for (n = 0; n < insn->n; n++) {
 118                 outb(chan, dev->iobase + PCMAD_CONVERT);
 119
 120                 for (i = 0; i < TIMEOUT; i++) {
 121                         if ((inb(dev->iobase + PCMAD_STATUS) & 0x3) == 0x3)
 122                                 break;
 123                 }
 124                 data[n] = inb(dev->iobase + PCMAD_LSB);
 125                 data[n] |= (inb(dev->iobase + PCMAD_MSB) << 8);
 126
 127                 if (devpriv->twos_comp)
 128                         data[n] ^= (1 << (this_board->n_ai_bits - 1));
 129         }
 130
 131         return n;
 132 }
 133
 134 /*
 135  * options:
 136  * 0    i/o base
 137  * 1    unused
 138  * 2    0=single ended 1=differential
 139  * 3    0=straight binary 1=two's comp
 140  */
 141 static int pcmad_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 142 {
 143         int ret;
 144         struct comedi_subdevice *s;
 145         unsigned long iobase;
 146
 147         iobase = it->options[0];
 148         printk(KERN_INFO "comedi%d: pcmad: 0x%04lx ", dev->minor, iobase);
 149         if (!request_region(iobase, PCMAD_SIZE, "pcmad")) {
 150                 printk(KERN_CONT "I/O port conflict\n");
 151                 return -EIO;
 152         }
 153         printk(KERN_CONT "\n");
 154         dev->iobase = iobase;
 155
 156         ret = alloc_subdevices(dev, 1);
 157         if (ret < 0)
 158                 return ret;
 159
 160         ret = alloc_private(dev, sizeof(struct pcmad_priv_struct));
 161         if (ret < 0)
 162                 return ret;
 163
 164         dev->board_name = this_board->name;
 165
 166         s = dev->subdevices + 0;
 167         s->type = COMEDI_SUBD_AI;
 168         s->subdev_flags = SDF_READABLE | AREF_GROUND;
 169         s->n_chan = 16;         /* XXX */
 170         s->len_chanlist = 1;
 171         s->insn_read = pcmad_ai_insn_read;
 172         s->maxdata = (1 << this_board->n_ai_bits) - 1;
 173         s->range_table = &range_unknown;
 174
 175         return 0;
 176 }
 177
 178 static int pcmad_detach(struct comedi_device *dev)
 179 {
 180         printk(KERN_INFO "comedi%d: pcmad: remove\n", dev->minor);
 181
 182         if (dev->irq)
 183                 free_irq(dev->irq, dev);
 184
 185         if (dev->iobase)
 186                 release_region(dev->iobase, PCMAD_SIZE);
 187
 188         return 0;
 189 }
 190
 191 MODULE_AUTHOR("Comedi http://www.comedi.org");
 192 MODULE_DESCRIPTION("Comedi low-level driver");
 193 MODULE_LICENSE("GPL");