proc.c

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/*
 *  ISA Plug & Play support
 *  Copyright (c) by Jaroslav Kysela <[email protected]>
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/module.h>
#include <linux/isapnp.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <asm/uaccess.h>

extern struct pnp_protocol isapnp_protocol;

static struct proc_dir_entry *isapnp_proc_bus_dir = NULL;

static loff_t isapnp_proc_bus_lseek(struct file *file, loff_t off, int whence)
{
    loff_t new = -1;
    struct inode *inode = file->f_path.dentry->d_inode;

    mutex_lock(&inode->i_mutex);
    switch (whence) {
    case 0:
        new = off;
        break;
    case 1:
        new = file->f_pos + off;
        break;
    case 2:
        new = 256 + off;
        break;
    }
    if (new < 0 || new > 256)
        new = -EINVAL;
    else
        file->f_pos = new;
    mutex_unlock(&inode->i_mutex);
    return new;
}

static ssize_t isapnp_proc_bus_read(struct file *file, char __user * buf,
                    size_t nbytes, loff_t * ppos)
{
    struct inode *ino = file->f_path.dentry->d_inode;
    struct proc_dir_entry *dp = PDE(ino);
    struct pnp_dev *dev = dp->data;
    int pos = *ppos;
    int cnt, size = 256;

    if (pos >= size)
        return 0;
    if (nbytes >= size)
        nbytes = size;
    if (pos + nbytes > size)
        nbytes = size - pos;
    cnt = nbytes;

    if (!access_ok(VERIFY_WRITE, buf, cnt))
        return -EINVAL;

    isapnp_cfg_begin(dev->card->number, dev->number);
    for (; pos < 256 && cnt > 0; pos++, buf++, cnt--) {
        unsigned char val;
        val = isapnp_read_byte(pos);
        __put_user(val, buf);
    }
    isapnp_cfg_end();

    *ppos = pos;
    return nbytes;
}

static const struct file_operations isapnp_proc_bus_file_operations = {
    .owner  = THIS_MODULE,
    .llseek = isapnp_proc_bus_lseek,
    .read = isapnp_proc_bus_read,
};

static int isapnp_proc_attach_device(struct pnp_dev *dev)
{
    struct pnp_card *bus = dev->card;
    struct proc_dir_entry *de, *e;
    char name[16];

    if (!(de = bus->procdir)) {
        sprintf(name, "%02x", bus->number);
        de = bus->procdir = proc_mkdir(name, isapnp_proc_bus_dir);
        if (!de)
            return -ENOMEM;
    }
    sprintf(name, "%02x", dev->number);
    e = dev->procent = proc_create_data(name, S_IFREG | S_IRUGO, de,
            &isapnp_proc_bus_file_operations, dev);
    if (!e)
        return -ENOMEM;
    e->size = 256;
    return 0;
}

int __init isapnp_proc_init(void)
{
    struct pnp_dev *dev;

    isapnp_proc_bus_dir = proc_mkdir("bus/isapnp", NULL);
    protocol_for_each_dev(&isapnp_protocol, dev) {
        isapnp_proc_attach_device(dev);
    }
    return 0;
}