inode.c

Usb1.1驱动c语言源代码

/*****************************************************************************/

/*
 *	inode.c  --  Inode/Dentry functions for the USB device file system.
 *
 *	Copyright (C) 2000
 *          Thomas Sailer ([e-mail])
 *
 *	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.
 *
 *  $Id: inode.c,v 1.6 2000/03/13 16:44:38 acher Exp $
 *
 *  History:
 *   0.1  04.01.2000  Created
 */

/*****************************************************************************/

#define __NO_VERSION__
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/smp_lock.h>
#include <linux/locks.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/usb.h>
#include <asm/uaccess.h>


#include "usbdevice_fs.h"

/* --------------------------------------------------------------------- */

static LIST_HEAD(superlist);

struct special {
	const char *name;
	struct file_operations *fops;
	struct list_head inodes;
};

static struct special special[] = { 
	{ "devices", &usbdevfs_devices_fops, },
	{ "drivers", &usbdevfs_drivers_fops, }
};

#define NRSPECIAL (sizeof(special)/sizeof(special[0]))

/* --------------------------------------------------------------------- */

static int dnumber(struct dentry *dentry)
{
	const char *name;
	unsigned int s;

	if (dentry->d_name.len != 3)
		return -1;
	name = dentry->d_name.name;
	if (name[0] < '0' || name[0] > '9' ||
	    name[1] < '0' || name[1] > '9' ||
	    name[2] < '0' || name[2] > '9')
		return -1;
	s = name[0] - '0';
	s = s * 10 + name[1] - '0';
	s = s * 10 + name[2] - '0';
	return s;
}

/*
 * utility functions; should be called with the kernel lock held
 * to protect against busses/devices appearing/disappearing
 */

static void new_dev_inode(struct usb_device *dev, struct super_block *sb)
{
	struct inode *inode;
	unsigned int devnum = dev->devnum;
	unsigned int busnum = dev->bus->busnum;

	if (devnum < 1 || devnum > 127 || busnum > 255)
		return;
	inode = iget(sb, IDEVICE | (busnum << 8) | devnum);
	if (!inode) {
		printk(KERN_ERR "usbdevfs: cannot create inode for bus %u device %u\n", busnum, devnum);
		return;
	}
	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	inode->i_uid = sb->u.usbdevfs_sb.devuid;
	inode->i_gid = sb->u.usbdevfs_sb.devgid;
	inode->i_mode = sb->u.usbdevfs_sb.devmode | S_IFREG;
	inode->i_fop = &usbdevfs_device_file_operations;
	inode->i_size = sizeof(struct usb_device_descriptor);
	inode->u.usbdev_i.p.dev = dev;
	list_add_tail(&inode->u.usbdev_i.slist, &sb->u.usbdevfs_sb.ilist);
	list_add_tail(&inode->u.usbdev_i.dlist, &dev->inodes);
}

static void recurse_new_dev_inode(struct usb_device *dev, struct super_block *sb)
{
	unsigned int i;

	if (!dev)
		return;
	new_dev_inode(dev, sb);
	for (i = 0; i < dev->maxchild; i++) {
                if (!dev->children[i])
                        continue;
		recurse_new_dev_inode(dev->children[i], sb);
	}
}

static void new_bus_inode(struct usb_bus *bus, struct super_block *sb)
{
	struct inode *inode;
	unsigned int busnum = bus->busnum;

	if (busnum > 255)
		return;
	inode = iget(sb, IBUS | (busnum << 8));
	if (!inode) {
		printk(KERN_ERR "usbdevfs: cannot create inode for bus %u\n", busnum);
		return;
	}
	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	inode->i_uid = sb->u.usbdevfs_sb.busuid;
	inode->i_gid = sb->u.usbdevfs_sb.busgid;
	inode->i_mode = sb->u.usbdevfs_sb.busmode | S_IFDIR;
	inode->i_op = &usbdevfs_bus_inode_operations;
	inode->i_fop = &usbdevfs_bus_file_operations;
	inode->u.usbdev_i.p.bus = bus;
	list_add_tail(&inode->u.usbdev_i.slist, &sb->u.usbdevfs_sb.ilist);
	list_add_tail(&inode->u.usbdev_i.dlist, &bus->inodes);
}

static void free_inode(struct inode *inode)
{
	inode->u.usbdev_i.p.bus = NULL;
	inode->u.usbdev_i.p.dev = NULL;
	inode->i_mode &= ~S_IRWXUGO;
	inode->i_uid = inode->i_gid = 0;
	inode->i_size = 0;
	list_del(&inode->u.usbdev_i.slist);
	INIT_LIST_HEAD(&inode->u.usbdev_i.slist);
	list_del(&inode->u.usbdev_i.dlist);
	INIT_LIST_HEAD(&inode->u.usbdev_i.dlist);
	iput(inode);
}

static struct usb_bus *usbdevfs_findbus(int busnr)
{
        struct list_head *list;
        struct usb_bus *bus;

        for (list = usb_bus_list.next; list != &usb_bus_list; list = list->next) {
                bus = list_entry(list, struct usb_bus, bus_list);
                if (bus->busnum == busnr)
                        return bus;
        }
        return NULL;
}

#if 0
static struct usb_device *finddev(struct usb_device *dev, int devnr)
{
        unsigned int i;
        struct usb_device *d2;

        if (!dev)
                return NULL;
        if (dev->devnum == devnr)
                return dev;
        for (i = 0; i < dev->maxchild; i++) {
                if (!dev->children[i])
                        continue;
                if ((d2 = finddev(dev->children[i], devnr)))
                        return d2;
        }
        return NULL;
}

static struct usb_device *usbdevfs_finddevice(struct usb_bus *bus, int devnr)
{
        return finddev(bus->root_hub, devnr);
}
#endif

/* --------------------------------------------------------------------- */

static int usbdevfs_revalidate(struct dentry *dentry, int flags)
{
	struct inode *inode = dentry->d_inode;

        if (!inode)
                return 0;
	if (ITYPE(inode->i_ino) == IBUS && !inode->u.usbdev_i.p.bus)
		return 0;
	if (ITYPE(inode->i_ino) == IDEVICE && !inode->u.usbdev_i.p.dev)
		return 0;
	return 1;
}

static struct dentry_operations usbdevfs_dentry_operations = {
       d_revalidate:   usbdevfs_revalidate,
};

static struct dentry *usbdevfs_root_lookup(struct inode *dir, struct dentry *dentry)
{
	int busnr;
	unsigned long ino = 0;
	unsigned int i;
	struct inode *inode;

	/* sanity check */
	if (dir->i_ino != IROOT)
		return ERR_PTR(-EINVAL);
	dentry->d_op = &usbdevfs_dentry_operations;
	busnr = dnumber(dentry);
	if (busnr >= 0 && busnr <= 255)
		ino = IBUS | (busnr << 8);
	if (!ino) {
		for (i = 0; i < NRSPECIAL; i++) {
			if (strlen(special[i].name) == dentry->d_name.len && 
			    !strncmp(special[i].name, dentry->d_name.name, dentry->d_name.len)) {
				ino = ISPECIAL | (i + IROOT + 1);
				break;
			}
		}
	}
	if (!ino)
		return ERR_PTR(-ENOENT);
	inode = iget(dir->i_sb, ino);
	if (!inode)
		return ERR_PTR(-EINVAL);
	if (inode && ITYPE(ino) == IBUS && inode->u.usbdev_i.p.bus == NULL) {
		iput(inode);
		inode = NULL;
	}
	d_add(dentry, inode);
	return NULL;
}

static struct dentry *usbdevfs_bus_lookup(struct inode *dir, struct dentry *dentry)
{
	struct inode *inode;
	int devnr;

	/* sanity check */
	if (ITYPE(dir->i_ino) != IBUS)
		return ERR_PTR(-EINVAL);
	dentry->d_op = &usbdevfs_dentry_operations;
	devnr = dnumber(dentry);
	if (devnr < 1 || devnr > 127)
		return ERR_PTR(-ENOENT);
	inode = iget(dir->i_sb, IDEVICE | (dir->i_ino & (0xff << 8)) | devnr);
	if (!inode)
		return ERR_PTR(-EINVAL);
	if (inode && inode->u.usbdev_i.p.dev == NULL) {
		iput(inode);
		inode = NULL;
	}
	d_add(dentry, inode);
	return NULL;
}

static int usbdevfs_root_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
	struct inode *inode = filp->f_dentry->d_inode;
	unsigned long ino = inode->i_ino;
	struct special *spec;
	struct list_head *list;
	struct usb_bus *bus;
	char numbuf[8];
	unsigned int i;

	/* sanity check */
	if (ino != IROOT)
		return -EINVAL;
	i = filp->f_pos;
	switch (i) {
	case 0:
		if (filldir(dirent, ".", 1, i, IROOT) < 0)
			return 0;
		filp->f_pos++;
		i++;
		/* fall through */

	case 1:
		if (filldir(dirent, "..", 2, i, IROOT) < 0)
			return 0;
		filp->f_pos++;
		i++;
		/* fall through */

	default:
		
		while (i >= 2 && i < 2+NRSPECIAL) {
			spec = &special[filp->f_pos-2];
			if (filldir(dirent, spec->name, strlen(spec->name), i, ISPECIAL | (filp->f_pos-2+IROOT)) < 0)
				return 0;
			filp->f_pos++;
			i++;
		}
		if (i < 2+NRSPECIAL)
			return 0;
		i -= 2+NRSPECIAL;
		lock_kernel();
		for (list = usb_bus_list.next; list != &usb_bus_list; list = list->next) {
			if (i > 0) {
				i--;
				continue;
			}
			bus = list_entry(list, struct usb_bus, bus_list);
			sprintf(numbuf, "%03d", bus->busnum);
			if (filldir(dirent, numbuf, 3, filp->f_pos, IBUS | ((bus->busnum & 0xff) << 8)) < 0)
				break;
			filp->f_pos++;
		}
		unlock_kernel();
		return 0;
	}
}

static int bus_readdir(struct usb_device *dev, unsigned long ino, int pos, struct file *filp, void *dirent, filldir_t filldir)
{
	char numbuf[8];
	unsigned int i;

	if (!dev)
		return pos;
	sprintf(numbuf, "%03d", dev->devnum);
	if (pos > 0)
		pos--;
	else {
		if (filldir(dirent, numbuf, 3, filp->f_pos, ino | (dev->devnum & 0xff)) < 0)
			return -1;
		filp->f_pos++;
	}
	for (i = 0; i < dev->maxchild; i++) {
		if (!dev->children[i])
			continue;
		pos = bus_readdir(dev->children[i], ino, pos, filp, dirent, filldir);
		if (pos < 0)