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 <linux/smp_lock.h>
  25 #include <asm/uaccess.h>
  26
  27 extern struct pnp_protocol isapnp_protocol;
  28
  29 static struct proc_dir_entry *isapnp_proc_bus_dir = NULL;
  30
  31 static loff_t isapnp_proc_bus_lseek(struct file *file, loff_t off, int whence)
  32 {
  33         loff_t new = -1;
  34         struct inode *inode = file->f_path.dentry->d_inode;
  35
  36         mutex_lock(&inode->i_mutex);
  37         switch (whence) {
  38         case 0:
  39                 new = off;
  40                 break;
  41         case 1:
  42                 new = file->f_pos + off;
  43                 break;
  44         case 2:
  45                 new = 256 + off;
  46                 break;
  47         }
  48         if (new < 0 || new > 256)
  49                 new = -EINVAL;
  50         else
  51                 file->f_pos = new;
  52         mutex_unlock(&inode->i_mutex);
  53         return new;
  54 }
  55
  56 static ssize_t isapnp_proc_bus_read(struct file *file, char __user * buf,
  57                                     size_t nbytes, loff_t * ppos)
  58 {
  59         struct inode *ino = file->f_path.dentry->d_inode;
  60         struct proc_dir_entry *dp = PDE(ino);
  61         struct pnp_dev *dev = dp->data;
  62         int pos = *ppos;
  63         int cnt, size = 256;
  64
  65         if (pos >= size)
  66                 return 0;
  67         if (nbytes >= size)
  68                 nbytes = size;
  69         if (pos + nbytes > size)
  70                 nbytes = size - pos;
  71         cnt = nbytes;
  72
  73         if (!access_ok(VERIFY_WRITE, buf, cnt))
  74                 return -EINVAL;
  75
  76         isapnp_cfg_begin(dev->card->number, dev->number);
  77         for (; pos < 256 && cnt > 0; pos++, buf++, cnt--) {
  78                 unsigned char val;
  79                 val = isapnp_read_byte(pos);
  80                 __put_user(val, buf);
  81         }
  82         isapnp_cfg_end();
  83
  84         *ppos = pos;
  85         return nbytes;
  86 }
  87
  88 static const struct file_operations isapnp_proc_bus_file_operations = {
  89         .owner  = THIS_MODULE,
  90         .llseek = isapnp_proc_bus_lseek,
  91         .read = isapnp_proc_bus_read,
  92 };
  93
  94 static int isapnp_proc_attach_device(struct pnp_dev *dev)
  95 {
  96         struct pnp_card *bus = dev->card;
  97         struct proc_dir_entry *de, *e;
  98         char name[16];
  99
 100         if (!(de = bus->procdir)) {
 101                 sprintf(name, "%02x", bus->number);
 102                 de = bus->procdir = proc_mkdir(name, isapnp_proc_bus_dir);
 103                 if (!de)
 104                         return -ENOMEM;
 105         }
 106         sprintf(name, "%02x", dev->number);
 107         e = dev->procent = proc_create_data(name, S_IFREG | S_IRUGO, de,
 108                         &isapnp_proc_bus_file_operations, dev);
 109         if (!e)
 110                 return -ENOMEM;
 111         e->size = 256;
 112         return 0;
 113 }
 114
 115 int __init isapnp_proc_init(void)
 116 {
 117         struct pnp_dev *dev;
 118
 119         isapnp_proc_bus_dir = proc_mkdir("bus/isapnp", NULL);
 120         protocol_for_each_dev(&isapnp_protocol, dev) {
 121                 isapnp_proc_attach_device(dev);
 122         }
 123         return 0;
 124 }