drivers/pnp/isapnp/proc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  ISA Plug & Play support
   4  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   5  */
   6
   7 #include <linux/module.h>
   8 #include <linux/isapnp.h>
   9 #include <linux/proc_fs.h>
  10 #include <linux/init.h>
  11 #include <linux/uaccess.h>
  12
  13 extern struct pnp_protocol isapnp_protocol;
  14
  15 static struct proc_dir_entry *isapnp_proc_bus_dir = NULL;
  16
  17 static loff_t isapnp_proc_bus_lseek(struct file *file, loff_t off, int whence)
  18 {
  19         return fixed_size_llseek(file, off, whence, 256);
  20 }
  21
  22 static ssize_t isapnp_proc_bus_read(struct file *file, char __user * buf,
  23                                     size_t nbytes, loff_t * ppos)
  24 {
  25         struct pnp_dev *dev = PDE_DATA(file_inode(file));
  26         int pos = *ppos;
  27         int cnt, size = 256;
  28
  29         if (pos >= size)
  30                 return 0;
  31         if (nbytes >= size)
  32                 nbytes = size;
  33         if (pos + nbytes > size)
  34                 nbytes = size - pos;
  35         cnt = nbytes;
  36
  37         if (!access_ok(buf, cnt))
  38                 return -EINVAL;
  39
  40         isapnp_cfg_begin(dev->card->number, dev->number);
  41         for (; pos < 256 && cnt > 0; pos++, buf++, cnt--) {
  42                 unsigned char val;
  43                 val = isapnp_read_byte(pos);
  44                 __put_user(val, buf);
  45         }
  46         isapnp_cfg_end();
  47
  48         *ppos = pos;
  49         return nbytes;
  50 }
  51
  52 static const struct proc_ops isapnp_proc_bus_proc_ops = {
  53         .proc_lseek     = isapnp_proc_bus_lseek,
  54         .proc_read      = isapnp_proc_bus_read,
  55 };
  56
  57 static int isapnp_proc_attach_device(struct pnp_dev *dev)
  58 {
  59         struct pnp_card *bus = dev->card;
  60         struct proc_dir_entry *de, *e;
  61         char name[16];
  62
  63         if (!(de = bus->procdir)) {
  64                 sprintf(name, "%02x", bus->number);
  65                 de = bus->procdir = proc_mkdir(name, isapnp_proc_bus_dir);
  66                 if (!de)
  67                         return -ENOMEM;
  68         }
  69         sprintf(name, "%02x", dev->number);
  70         e = dev->procent = proc_create_data(name, S_IFREG | S_IRUGO, de,
  71                                             &isapnp_proc_bus_proc_ops, dev);
  72         if (!e)
  73                 return -ENOMEM;
  74         proc_set_size(e, 256);
  75         return 0;
  76 }
  77
  78 int __init isapnp_proc_init(void)
  79 {
  80         struct pnp_dev *dev;
  81
  82         isapnp_proc_bus_dir = proc_mkdir("bus/isapnp", NULL);
  83         protocol_for_each_dev(&isapnp_protocol, dev) {
  84                 isapnp_proc_attach_device(dev);
  85         }
  86         return 0;
  87 }