pnp/isapnp/proc.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  *  ISA Plug & Play support
0004  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
0005  */
0006
0007 #include <linux/module.h>
0008 #include <linux/isapnp.h>
0009 #include <linux/proc_fs.h>
0010 #include <linux/init.h>
0011 #include <linux/uaccess.h>
0012
0013 extern struct pnp_protocol isapnp_protocol;
0014
0015 static struct proc_dir_entry *isapnp_proc_bus_dir = NULL;
0016
0017 static loff_t isapnp_proc_bus_lseek(struct file *file, loff_t off, int whence)
0018 {
0019     return fixed_size_llseek(file, off, whence, 256);
0020 }
0021
0022 static ssize_t isapnp_proc_bus_read(struct file *file, char __user * buf,
0023                     size_t nbytes, loff_t * ppos)
0024 {
0025     struct pnp_dev *dev = pde_data(file_inode(file));
0026     int pos = *ppos;
0027     int cnt, size = 256;
0028
0029     if (pos >= size)
0030         return 0;
0031     if (nbytes >= size)
0032         nbytes = size;
0033     if (pos + nbytes > size)
0034         nbytes = size - pos;
0035     cnt = nbytes;
0036
0037     if (!access_ok(buf, cnt))
0038         return -EINVAL;
0039
0040     isapnp_cfg_begin(dev->card->number, dev->number);
0041     for (; pos < 256 && cnt > 0; pos++, buf++, cnt--) {
0042         unsigned char val;
0043         val = isapnp_read_byte(pos);
0044         __put_user(val, buf);
0045     }
0046     isapnp_cfg_end();
0047
0048     *ppos = pos;
0049     return nbytes;
0050 }
0051
0052 static const struct proc_ops isapnp_proc_bus_proc_ops = {
0053     .proc_lseek = isapnp_proc_bus_lseek,
0054     .proc_read  = isapnp_proc_bus_read,
0055 };
0056
0057 static int isapnp_proc_attach_device(struct pnp_dev *dev)
0058 {
0059     struct pnp_card *bus = dev->card;
0060     char name[16];
0061
0062     if (!bus->procdir) {
0063         sprintf(name, "%02x", bus->number);
0064         bus->procdir = proc_mkdir(name, isapnp_proc_bus_dir);
0065         if (!bus->procdir)
0066             return -ENOMEM;
0067     }
0068     sprintf(name, "%02x", dev->number);
0069     dev->procent = proc_create_data(name, S_IFREG | S_IRUGO, bus->procdir,
0070                         &isapnp_proc_bus_proc_ops, dev);
0071     if (!dev->procent)
0072         return -ENOMEM;
0073     proc_set_size(dev->procent, 256);
0074     return 0;
0075 }
0076
0077 int __init isapnp_proc_init(void)
0078 {
0079     struct pnp_dev *dev;
0080
0081     isapnp_proc_bus_dir = proc_mkdir("bus/isapnp", NULL);
0082     protocol_for_each_dev(&isapnp_protocol, dev) {
0083         isapnp_proc_attach_device(dev);
0084     }
0085     return 0;
0086 }