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         char name[16];
  61
  62         if (!bus->procdir) {
  63                 sprintf(name, "%02x", bus->number);
  64                 bus->procdir = proc_mkdir(name, isapnp_proc_bus_dir);
  65                 if (!bus->procdir)
  66                         return -ENOMEM;
  67         }
  68         sprintf(name, "%02x", dev->number);
  69         dev->procent = proc_create_data(name, S_IFREG | S_IRUGO, bus->procdir,
  70                                             &isapnp_proc_bus_proc_ops, dev);
  71         if (!dev->procent)
  72                 return -ENOMEM;
  73         proc_set_size(dev->procent, 256);
  74         return 0;
  75 }
  76
  77 int __init isapnp_proc_init(void)
  78 {
  79         struct pnp_dev *dev;
  80
  81         isapnp_proc_bus_dir = proc_mkdir("bus/isapnp", NULL);
  82         protocol_for_each_dev(&isapnp_protocol, dev) {
  83                 isapnp_proc_attach_device(dev);
  84         }
  85         return 0;
  86 }