drivers/staging/comedi/kcomedilib/kcomedilib_main.c

   1 /*
   2     kcomedilib/kcomedilib.c
   3     a comedlib interface for kernel modules
   4
   5     COMEDI - Linux Control and Measurement Device Interface
   6     Copyright (C) 1997-2000 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 #define __NO_VERSION__
  25 #include <linux/module.h>
  26
  27 #include <linux/errno.h>
  28 #include <linux/kernel.h>
  29 #include <linux/sched.h>
  30 #include <linux/fcntl.h>
  31 #include <linux/delay.h>
  32 #include <linux/ioport.h>
  33 #include <linux/mm.h>
  34 #include <linux/io.h>
  35
  36 #include "../comedi.h"
  37 #include "../comedilib.h"
  38 #include "../comedidev.h"
  39
  40 MODULE_AUTHOR("David Schleef <ds@schleef.org>");
  41 MODULE_DESCRIPTION("Comedi kernel library");
  42 MODULE_LICENSE("GPL");
  43
  44 struct comedi_device *comedi_open(const char *filename)
  45 {
  46         struct comedi_device_file_info *dev_file_info;
  47         struct comedi_device *dev;
  48         unsigned int minor;
  49
  50         if (strncmp(filename, "/dev/comedi", 11) != 0)
  51                 return NULL;
  52
  53         minor = simple_strtoul(filename + 11, NULL, 0);
  54
  55         if (minor >= COMEDI_NUM_BOARD_MINORS)
  56                 return NULL;
  57
  58         dev_file_info = comedi_get_device_file_info(minor);
  59         if (dev_file_info == NULL)
  60                 return NULL;
  61         dev = dev_file_info->device;
  62
  63         if (dev == NULL || !dev->attached)
  64                 return NULL;
  65
  66         if (!try_module_get(dev->driver->module))
  67                 return NULL;
  68
  69         return dev;
  70 }
  71 EXPORT_SYMBOL(comedi_open);
  72
  73 int comedi_close(struct comedi_device *d)
  74 {
  75         struct comedi_device *dev = (struct comedi_device *)d;
  76
  77         module_put(dev->driver->module);
  78
  79         return 0;
  80 }
  81 EXPORT_SYMBOL(comedi_close);
  82
  83 static int comedi_do_insn(struct comedi_device *dev, struct comedi_insn *insn)
  84 {
  85         struct comedi_subdevice *s;
  86         int ret = 0;
  87
  88         /* a subdevice instruction */
  89         if (insn->subdev >= dev->n_subdevices) {
  90                 ret = -EINVAL;
  91                 goto error;
  92         }
  93         s = dev->subdevices + insn->subdev;
  94
  95         if (s->type == COMEDI_SUBD_UNUSED) {
  96                 printk(KERN_ERR "%d not useable subdevice\n", insn->subdev);
  97                 ret = -EIO;
  98                 goto error;
  99         }
 100
 101         /* XXX check lock */
 102
 103         ret = comedi_check_chanlist(s, 1, &insn->chanspec);
 104         if (ret < 0) {
 105                 printk(KERN_ERR "bad chanspec\n");
 106                 ret = -EINVAL;
 107                 goto error;
 108         }
 109
 110         if (s->busy) {
 111                 ret = -EBUSY;
 112                 goto error;
 113         }
 114         s->busy = dev;
 115
 116         switch (insn->insn) {
 117         case INSN_BITS:
 118                 ret = s->insn_bits(dev, s, insn, insn->data);
 119                 break;
 120         case INSN_CONFIG:
 121                 /* XXX should check instruction length */
 122                 ret = s->insn_config(dev, s, insn, insn->data);
 123                 break;
 124         default:
 125                 ret = -EINVAL;
 126                 break;
 127         }
 128
 129         s->busy = NULL;
 130 error:
 131
 132         return ret;
 133 }
 134
 135 int comedi_dio_config(struct comedi_device *dev, unsigned int subdev,
 136                       unsigned int chan, unsigned int io)
 137 {
 138         struct comedi_insn insn;
 139
 140         memset(&insn, 0, sizeof(insn));
 141         insn.insn = INSN_CONFIG;
 142         insn.n = 1;
 143         insn.data = &io;
 144         insn.subdev = subdev;
 145         insn.chanspec = CR_PACK(chan, 0, 0);
 146
 147         return comedi_do_insn(dev, &insn);
 148 }
 149 EXPORT_SYMBOL(comedi_dio_config);
 150
 151 int comedi_dio_bitfield(struct comedi_device *dev, unsigned int subdev,
 152                         unsigned int mask, unsigned int *bits)
 153 {
 154         struct comedi_insn insn;
 155         unsigned int data[2];
 156         int ret;
 157
 158         memset(&insn, 0, sizeof(insn));
 159         insn.insn = INSN_BITS;
 160         insn.n = 2;
 161         insn.data = data;
 162         insn.subdev = subdev;
 163
 164         data[0] = mask;
 165         data[1] = *bits;
 166
 167         ret = comedi_do_insn(dev, &insn);
 168
 169         *bits = data[1];
 170
 171         return ret;
 172 }
 173 EXPORT_SYMBOL(comedi_dio_bitfield);
 174
 175 int comedi_find_subdevice_by_type(struct comedi_device *dev, int type,
 176                                   unsigned int subd)
 177 {
 178         if (subd > dev->n_subdevices)
 179                 return -ENODEV;
 180
 181         for (; subd < dev->n_subdevices; subd++) {
 182                 if (dev->subdevices[subd].type == type)
 183                         return subd;
 184         }
 185         return -1;
 186 }
 187 EXPORT_SYMBOL(comedi_find_subdevice_by_type);
 188
 189 int comedi_get_n_channels(struct comedi_device *dev, unsigned int subdevice)
 190 {
 191         struct comedi_subdevice *s = dev->subdevices + subdevice;
 192
 193         return s->n_chan;
 194 }
 195 EXPORT_SYMBOL(comedi_get_n_channels);