[net-next-2.6.git] / drivers / usb / core / file.c

/*
 * drivers/usb/file.c
 *
 * (C) Copyright Linus Torvalds 1999
 * (C) Copyright Johannes Erdfelt 1999-2001
 * (C) Copyright Andreas Gal 1999
 * (C) Copyright Gregory P. Smith 1999
 * (C) Copyright Deti Fliegl 1999 (new USB architecture)
 * (C) Copyright Randy Dunlap 2000
 * (C) Copyright David Brownell 2000-2001 (kernel hotplug, usb_device_id,
 	more docs, etc)
 * (C) Copyright Yggdrasil Computing, Inc. 2000
 *     (usb_device_id matching changes by Adam J. Richter)
 * (C) Copyright Greg Kroah-Hartman 2002-2003
 *
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/spinlock.h>
#include <linux/errno.h>

#ifdef CONFIG_USB_DEBUG
	#define DEBUG
#else
	#undef DEBUG
#endif
#include <linux/usb.h>

#include "usb.h"

#define MAX_USB_MINORS	256
static struct file_operations *usb_minors[MAX_USB_MINORS];
static DEFINE_SPINLOCK(minor_lock);

static int usb_open(struct inode * inode, struct file * file)
{
	int minor = iminor(inode);
	struct file_operations *c;
	int err = -ENODEV;
	struct file_operations *old_fops, *new_fops = NULL;

	spin_lock (&minor_lock);
	c = usb_minors[minor];

	if (!c || !(new_fops = fops_get(c))) {
		spin_unlock(&minor_lock);
		return err;
	}
	spin_unlock(&minor_lock);

	old_fops = file->f_op;
	file->f_op = new_fops;
	/* Curiouser and curiouser... NULL ->open() as "no device" ? */
	if (file->f_op->open)
		err = file->f_op->open(inode,file);
	if (err) {
		fops_put(file->f_op);
		file->f_op = fops_get(old_fops);
	}
	fops_put(old_fops);
	return err;
}

static struct file_operations usb_fops = {
	.owner =	THIS_MODULE,
	.open =		usb_open,
};

static struct class *usb_class;

int usb_major_init(void)
{
	int error;

	error = register_chrdev(USB_MAJOR, "usb", &usb_fops);
	if (error) {
		err("unable to get major %d for usb devices", USB_MAJOR);
		goto out;
	}

	usb_class = class_create(THIS_MODULE, "usb");
	if (IS_ERR(usb_class)) {
		error = PTR_ERR(usb_class);
		err("class_create failed for usb devices");
		unregister_chrdev(USB_MAJOR, "usb");
		goto out;
	}

	devfs_mk_dir("usb");

out:
	return error;
}

void usb_major_cleanup(void)
{
	class_destroy(usb_class);
	devfs_remove("usb");
	unregister_chrdev(USB_MAJOR, "usb");
}

/**
 * usb_register_dev - register a USB device, and ask for a minor number
 * @intf: pointer to the usb_interface that is being registered
 * @class_driver: pointer to the usb_class_driver for this device
 *
 * This should be called by all USB drivers that use the USB major number.
 * If CONFIG_USB_DYNAMIC_MINORS is enabled, the minor number will be
 * dynamically allocated out of the list of available ones.  If it is not
 * enabled, the minor number will be based on the next available free minor,
 * starting at the class_driver->minor_base.
 *
 * This function also creates the devfs file for the usb device, if devfs
 * is enabled, and creates a usb class device in the sysfs tree.
 *
 * usb_deregister_dev() must be called when the driver is done with
 * the minor numbers given out by this function.
 *
 * Returns -EINVAL if something bad happens with trying to register a
 * device, and 0 on success.
 */
int usb_register_dev(struct usb_interface *intf,
		     struct usb_class_driver *class_driver)
{
	int retval = -EINVAL;
	int minor_base = class_driver->minor_base;
	int minor = 0;
	char name[BUS_ID_SIZE];
	char *temp;

#ifdef CONFIG_USB_DYNAMIC_MINORS
	/* 
	 * We don't care what the device tries to start at, we want to start
	 * at zero to pack the devices into the smallest available space with
	 * no holes in the minor range.
	 */
	minor_base = 0;
#endif
	intf->minor = -1;

	dbg ("looking for a minor, starting at %d", minor_base);

	if (class_driver->fops == NULL)
		goto exit;

	spin_lock (&minor_lock);
	for (minor = minor_base; minor < MAX_USB_MINORS; ++minor) {
		if (usb_minors[minor])
			continue;

		usb_minors[minor] = class_driver->fops;

		retval = 0;
		break;
	}
	spin_unlock (&minor_lock);

	if (retval)
		goto exit;

	intf->minor = minor;

	/* handle the devfs registration */
	snprintf(name, BUS_ID_SIZE, class_driver->name, minor - minor_base);
	devfs_mk_cdev(MKDEV(USB_MAJOR, minor), class_driver->mode, name);

	/* create a usb class device for this usb interface */
	temp = strrchr(name, '/');
	if (temp && (temp[1] != 0x00))
		++temp;
	else
		temp = name;
	intf->class_dev = class_device_create(usb_class, NULL,
					      MKDEV(USB_MAJOR, minor),
					      &intf->dev, "%s", temp);
	if (IS_ERR(intf->class_dev)) {
		spin_lock (&minor_lock);
		usb_minors[intf->minor] = NULL;
		spin_unlock (&minor_lock);
		devfs_remove (name);
		retval = PTR_ERR(intf->class_dev);
	}
exit:
	return retval;
}
EXPORT_SYMBOL(usb_register_dev);

/**
 * usb_deregister_dev - deregister a USB device's dynamic minor.
 * @intf: pointer to the usb_interface that is being deregistered
 * @class_driver: pointer to the usb_class_driver for this device
 *
 * Used in conjunction with usb_register_dev().  This function is called
 * when the USB driver is finished with the minor numbers gotten from a
 * call to usb_register_dev() (usually when the device is disconnected
 * from the system.)
 *
 * This function also cleans up the devfs file for the usb device, if devfs
 * is enabled, and removes the usb class device from the sysfs tree.
 * 
 * This should be called by all drivers that use the USB major number.
 */
void usb_deregister_dev(struct usb_interface *intf,
			struct usb_class_driver *class_driver)
{
	int minor_base = class_driver->minor_base;
	char name[BUS_ID_SIZE];

#ifdef CONFIG_USB_DYNAMIC_MINORS
	minor_base = 0;
#endif

	if (intf->minor == -1)
		return;

	dbg ("removing %d minor", intf->minor);

	spin_lock (&minor_lock);
	usb_minors[intf->minor] = NULL;
	spin_unlock (&minor_lock);

	snprintf(name, BUS_ID_SIZE, class_driver->name, intf->minor - minor_base);
	devfs_remove (name);
	class_device_destroy(usb_class, MKDEV(USB_MAJOR, intf->minor));
	intf->class_dev = NULL;
	intf->minor = -1;
}
EXPORT_SYMBOL(usb_deregister_dev);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* drivers/usb/file.c
	3	*
	4	* (C) Copyright Linus Torvalds 1999
	5	* (C) Copyright Johannes Erdfelt 1999-2001
	6	* (C) Copyright Andreas Gal 1999
	7	* (C) Copyright Gregory P. Smith 1999
	8	* (C) Copyright Deti Fliegl 1999 (new USB architecture)
	9	* (C) Copyright Randy Dunlap 2000
	10	* (C) Copyright David Brownell 2000-2001 (kernel hotplug, usb_device_id,
	11	more docs, etc)
	12	* (C) Copyright Yggdrasil Computing, Inc. 2000
	13	* (usb_device_id matching changes by Adam J. Richter)
	14	* (C) Copyright Greg Kroah-Hartman 2002-2003
	15	*
	16	*/
	17
	18	#include <linux/config.h>
	19	#include <linux/module.h>
	20	#include <linux/devfs_fs_kernel.h>
	21	#include <linux/spinlock.h>
	22	#include <linux/errno.h>
	23
	24	#ifdef CONFIG_USB_DEBUG
	25	#define DEBUG
	26	#else
	27	#undef DEBUG
	28	#endif
	29	#include <linux/usb.h>
	30
6d5e8254 GKH	31	#include "usb.h"
6d5e8254 GKH	32
1da177e4 LT	33	#define MAX_USB_MINORS 256
	34	static struct file_operations *usb_minors[MAX_USB_MINORS];
	35	static DEFINE_SPINLOCK(minor_lock);
	36
	37	static int usb_open(struct inode * inode, struct file * file)
	38	{
	39	int minor = iminor(inode);
	40	struct file_operations *c;
	41	int err = -ENODEV;
	42	struct file_operations old_fops, new_fops = NULL;
	43
	44	spin_lock (&minor_lock);
	45	c = usb_minors[minor];
	46
	47	if (!c \|\| !(new_fops = fops_get(c))) {
	48	spin_unlock(&minor_lock);
	49	return err;
	50	}
	51	spin_unlock(&minor_lock);
	52
	53	old_fops = file->f_op;
	54	file->f_op = new_fops;
	55	/* Curiouser and curiouser... NULL ->open() as "no device" ? */
	56	if (file->f_op->open)
	57	err = file->f_op->open(inode,file);
	58	if (err) {
	59	fops_put(file->f_op);
	60	file->f_op = fops_get(old_fops);
	61	}
	62	fops_put(old_fops);
	63	return err;
	64	}
	65
	66	static struct file_operations usb_fops = {
	67	.owner = THIS_MODULE,
	68	.open = usb_open,
	69	};
	70
56b22935	71	static struct class *usb_class;
1da177e4 LT	72
	73	int usb_major_init(void)
	74	{
	75	int error;
	76
	77	error = register_chrdev(USB_MAJOR, "usb", &usb_fops);
	78	if (error) {
	79	err("unable to get major %d for usb devices", USB_MAJOR);
	80	goto out;
	81	}
	82
56b22935	83	usb_class = class_create(THIS_MODULE, "usb");
1da177e4	84	if (IS_ERR(usb_class)) {
5cebfb75	85	error = PTR_ERR(usb_class);
56b22935	86	err("class_create failed for usb devices");
1da177e4 LT	87	unregister_chrdev(USB_MAJOR, "usb");
	88	goto out;
	89	}
	90
	91	devfs_mk_dir("usb");
	92
	93	out:
	94	return error;
	95	}
	96
	97	void usb_major_cleanup(void)
	98	{
56b22935	99	class_destroy(usb_class);
1da177e4 LT	100	devfs_remove("usb");
	101	unregister_chrdev(USB_MAJOR, "usb");
	102	}
	103
	104	/**
	105	* usb_register_dev - register a USB device, and ask for a minor number
	106	* @intf: pointer to the usb_interface that is being registered
	107	* @class_driver: pointer to the usb_class_driver for this device
	108	*
	109	* This should be called by all USB drivers that use the USB major number.
	110	* If CONFIG_USB_DYNAMIC_MINORS is enabled, the minor number will be
	111	* dynamically allocated out of the list of available ones. If it is not
	112	* enabled, the minor number will be based on the next available free minor,
	113	* starting at the class_driver->minor_base.
	114	*
	115	* This function also creates the devfs file for the usb device, if devfs
	116	* is enabled, and creates a usb class device in the sysfs tree.
	117	*
	118	* usb_deregister_dev() must be called when the driver is done with
	119	* the minor numbers given out by this function.
	120	*
	121	* Returns -EINVAL if something bad happens with trying to register a
	122	* device, and 0 on success.
	123	*/
	124	int usb_register_dev(struct usb_interface *intf,
	125	struct usb_class_driver *class_driver)
	126	{
	127	int retval = -EINVAL;
	128	int minor_base = class_driver->minor_base;
	129	int minor = 0;
	130	char name[BUS_ID_SIZE];
	131	char *temp;
	132
	133	#ifdef CONFIG_USB_DYNAMIC_MINORS
	134	/*
	135	* We don't care what the device tries to start at, we want to start
	136	* at zero to pack the devices into the smallest available space with
	137	* no holes in the minor range.
	138	*/
	139	minor_base = 0;
	140	#endif
	141	intf->minor = -1;
	142
	143	dbg ("looking for a minor, starting at %d", minor_base);
	144
	145	if (class_driver->fops == NULL)
	146	goto exit;
	147
	148	spin_lock (&minor_lock);
	149	for (minor = minor_base; minor < MAX_USB_MINORS; ++minor) {
	150	if (usb_minors[minor])
	151	continue;
	152
	153	usb_minors[minor] = class_driver->fops;
	154
	155	retval = 0;
	156	break;
	157	}
	158	spin_unlock (&minor_lock);
	159
	160	if (retval)
	161	goto exit;
	162
	163	intf->minor = minor;
164
165	/* handle the devfs registration */
166	snprintf(name, BUS_ID_SIZE, class_driver->name, minor - minor_base);
167	devfs_mk_cdev(MKDEV(USB_MAJOR, minor), class_driver->mode, name);
168
169	/* create a usb class device for this usb interface */
170	temp = strrchr(name, '/');
171	if (temp && (temp[1] != 0x00))
172	++temp;
173	else
174	temp = name;
53f46542 GKH	175	intf->class_dev = class_device_create(usb_class, NULL,
	176	MKDEV(USB_MAJOR, minor),
	177	&intf->dev, "%s", temp);
1da177e4 LT	178	if (IS_ERR(intf->class_dev)) {
	179	spin_lock (&minor_lock);
	180	usb_minors[intf->minor] = NULL;
	181	spin_unlock (&minor_lock);
	182	devfs_remove (name);
	183	retval = PTR_ERR(intf->class_dev);
	184	}
	185	exit:
	186	return retval;
	187	}
	188	EXPORT_SYMBOL(usb_register_dev);
	189
	190	/**
	191	* usb_deregister_dev - deregister a USB device's dynamic minor.
	192	* @intf: pointer to the usb_interface that is being deregistered
	193	* @class_driver: pointer to the usb_class_driver for this device
	194	*
	195	* Used in conjunction with usb_register_dev(). This function is called
	196	* when the USB driver is finished with the minor numbers gotten from a
	197	* call to usb_register_dev() (usually when the device is disconnected
	198	* from the system.)
	199	*
	200	* This function also cleans up the devfs file for the usb device, if devfs
	201	* is enabled, and removes the usb class device from the sysfs tree.
	202	*
	203	* This should be called by all drivers that use the USB major number.
	204	*/
	205	void usb_deregister_dev(struct usb_interface *intf,
	206	struct usb_class_driver *class_driver)
	207	{
	208	int minor_base = class_driver->minor_base;
	209	char name[BUS_ID_SIZE];
	210
	211	#ifdef CONFIG_USB_DYNAMIC_MINORS
	212	minor_base = 0;
	213	#endif
	214
	215	if (intf->minor == -1)
	216	return;
	217
	218	dbg ("removing %d minor", intf->minor);
	219
	220	spin_lock (&minor_lock);
	221	usb_minors[intf->minor] = NULL;
	222	spin_unlock (&minor_lock);
	223
	224	snprintf(name, BUS_ID_SIZE, class_driver->name, intf->minor - minor_base);
	225	devfs_remove (name);
56b22935	226	class_device_destroy(usb_class, MKDEV(USB_MAJOR, intf->minor));
1da177e4 LT	227	intf->class_dev = NULL;
	228	intf->minor = -1;
	229	}
	230	EXPORT_SYMBOL(usb_deregister_dev);
	231
	232