drivers/pnp/isapnp/proc.c

   1 /*
   2  *  ISA Plug & Play support
   3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4  *
   5  *   This program is free software; you can redistribute it and/or modify
   6  *   it under the terms of the GNU General Public License as published by
   7  *   the Free Software Foundation; either version 2 of the License, or
   8  *   (at your option) any later version.
   9  *
  10  *   This program is distributed in the hope that it will be useful,
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *   GNU General Public License for more details.
  14  *
  15  *   You should have received a copy of the GNU General Public License
  16  *   along with this program; if not, write to the Free Software
  17  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/isapnp.h>
  22 #include <linux/proc_fs.h>
  23 #include <linux/init.h>
  24 #include <asm/uaccess.h>
  25
  26 extern struct pnp_protocol isapnp_protocol;
  27
  28 static struct proc_dir_entry *isapnp_proc_bus_dir = NULL;
  29
  30 static loff_t isapnp_proc_bus_lseek(struct file *file, loff_t off, int whence)
  31 {
  32         loff_t new = -1;
  33         struct inode *inode = file_inode(file);
  34
  35         mutex_lock(&inode->i_mutex);
  36         switch (whence) {
  37         case 0:
  38                 new = off;
  39                 break;
  40         case 1:
  41                 new = file->f_pos + off;
  42                 break;
  43         case 2:
  44                 new = 256 + off;
  45                 break;
  46         }
  47         if (new < 0 || new > 256)
  48                 new = -EINVAL;
  49         else
  50                 file->f_pos = new;
  51         mutex_unlock(&inode->i_mutex);
  52         return new;
  53 }
  54
  55 static ssize_t isapnp_proc_bus_read(struct file *file, char __user * buf,
  56                                     size_t nbytes, loff_t * ppos)
  57 {
  58         struct pnp_dev *dev = PDE_DATA(file_inode(file));
  59         int pos = *ppos;
  60         int cnt, size = 256;
  61
  62         if (pos >= size)
  63                 return 0;
  64         if (nbytes >= size)
  65                 nbytes = size;
  66         if (pos + nbytes > size)
  67                 nbytes = size - pos;
  68         cnt = nbytes;
  69
  70         if (!access_ok(VERIFY_WRITE, buf, cnt))
  71                 return -EINVAL;
  72
  73         isapnp_cfg_begin(dev->card->number, dev->number);
  74         for (; pos < 256 && cnt > 0; pos++, buf++, cnt--) {
  75                 unsigned char val;
  76                 val = isapnp_read_byte(pos);
  77                 __put_user(val, buf);
  78         }
  79         isapnp_cfg_end();
  80
  81         *ppos = pos;
  82         return nbytes;
  83 }
  84
  85 static const struct file_operations isapnp_proc_bus_file_operations = {
  86         .owner  = THIS_MODULE,
  87         .llseek = isapnp_proc_bus_lseek,
  88         .read = isapnp_proc_bus_read,
  89 };
  90
  91 static int isapnp_proc_attach_device(struct pnp_dev *dev)
  92 {
  93         struct pnp_card *bus = dev->card;
  94         struct proc_dir_entry *de, *e;
  95         char name[16];
  96
  97         if (!(de = bus->procdir)) {
  98                 sprintf(name, "%02x", bus->number);
  99                 de = bus->procdir = proc_mkdir(name, isapnp_proc_bus_dir);
 100                 if (!de)
 101                         return -ENOMEM;
 102         }
 103         sprintf(name, "%02x", dev->number);
 104         e = dev->procent = proc_create_data(name, S_IFREG | S_IRUGO, de,
 105                         &isapnp_proc_bus_file_operations, dev);
 106         if (!e)
 107                 return -ENOMEM;
 108         e->size = 256;
 109         return 0;
 110 }
 111
 112 int __init isapnp_proc_init(void)
 113 {
 114         struct pnp_dev *dev;
 115
 116         isapnp_proc_bus_dir = proc_mkdir("bus/isapnp", NULL);
 117         protocol_for_each_dev(&isapnp_protocol, dev) {
 118                 isapnp_proc_attach_device(dev);
 119         }
 120         return 0;
 121 }