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,
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
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>
24 #ifdef CONFIG_USB_DEBUG
29 #include <linux/usb.h>
31 #define MAX_USB_MINORS 256
32 static struct file_operations *usb_minors[MAX_USB_MINORS];
33 static DEFINE_SPINLOCK(minor_lock);
35 static int usb_open(struct inode * inode, struct file * file)
37 int minor = iminor(inode);
38 struct file_operations *c;
40 struct file_operations *old_fops, *new_fops = NULL;
42 spin_lock (&minor_lock);
43 c = usb_minors[minor];
45 if (!c || !(new_fops = fops_get(c))) {
46 spin_unlock(&minor_lock);
49 spin_unlock(&minor_lock);
51 old_fops = file->f_op;
52 file->f_op = new_fops;
53 /* Curiouser and curiouser... NULL ->open() as "no device" ? */
55 err = file->f_op->open(inode,file);
58 file->f_op = fops_get(old_fops);
64 static struct file_operations usb_fops = {
69 static struct class_simple *usb_class;
71 int usb_major_init(void)
75 error = register_chrdev(USB_MAJOR, "usb", &usb_fops);
77 err("unable to get major %d for usb devices", USB_MAJOR);
81 usb_class = class_simple_create(THIS_MODULE, "usb");
82 if (IS_ERR(usb_class)) {
83 err("class_simple_create failed for usb devices");
84 unregister_chrdev(USB_MAJOR, "usb");
94 void usb_major_cleanup(void)
96 class_simple_destroy(usb_class);
98 unregister_chrdev(USB_MAJOR, "usb");
102 * usb_register_dev - register a USB device, and ask for a minor number
103 * @intf: pointer to the usb_interface that is being registered
104 * @class_driver: pointer to the usb_class_driver for this device
106 * This should be called by all USB drivers that use the USB major number.
107 * If CONFIG_USB_DYNAMIC_MINORS is enabled, the minor number will be
108 * dynamically allocated out of the list of available ones. If it is not
109 * enabled, the minor number will be based on the next available free minor,
110 * starting at the class_driver->minor_base.
112 * This function also creates the devfs file for the usb device, if devfs
113 * is enabled, and creates a usb class device in the sysfs tree.
115 * usb_deregister_dev() must be called when the driver is done with
116 * the minor numbers given out by this function.
118 * Returns -EINVAL if something bad happens with trying to register a
119 * device, and 0 on success.
121 int usb_register_dev(struct usb_interface *intf,
122 struct usb_class_driver *class_driver)
124 int retval = -EINVAL;
125 int minor_base = class_driver->minor_base;
127 char name[BUS_ID_SIZE];
130 #ifdef CONFIG_USB_DYNAMIC_MINORS
132 * We don't care what the device tries to start at, we want to start
133 * at zero to pack the devices into the smallest available space with
134 * no holes in the minor range.
140 dbg ("looking for a minor, starting at %d", minor_base);
142 if (class_driver->fops == NULL)
145 spin_lock (&minor_lock);
146 for (minor = minor_base; minor < MAX_USB_MINORS; ++minor) {
147 if (usb_minors[minor])
150 usb_minors[minor] = class_driver->fops;
155 spin_unlock (&minor_lock);
162 /* handle the devfs registration */
163 snprintf(name, BUS_ID_SIZE, class_driver->name, minor - minor_base);
164 devfs_mk_cdev(MKDEV(USB_MAJOR, minor), class_driver->mode, name);
166 /* create a usb class device for this usb interface */
167 temp = strrchr(name, '/');
168 if (temp && (temp[1] != 0x00))
172 intf->class_dev = class_simple_device_add(usb_class, MKDEV(USB_MAJOR, minor), &intf->dev, "%s", temp);
173 if (IS_ERR(intf->class_dev)) {
174 spin_lock (&minor_lock);
175 usb_minors[intf->minor] = NULL;
176 spin_unlock (&minor_lock);
178 retval = PTR_ERR(intf->class_dev);
183 EXPORT_SYMBOL(usb_register_dev);
186 * usb_deregister_dev - deregister a USB device's dynamic minor.
187 * @intf: pointer to the usb_interface that is being deregistered
188 * @class_driver: pointer to the usb_class_driver for this device
190 * Used in conjunction with usb_register_dev(). This function is called
191 * when the USB driver is finished with the minor numbers gotten from a
192 * call to usb_register_dev() (usually when the device is disconnected
195 * This function also cleans up the devfs file for the usb device, if devfs
196 * is enabled, and removes the usb class device from the sysfs tree.
198 * This should be called by all drivers that use the USB major number.
200 void usb_deregister_dev(struct usb_interface *intf,
201 struct usb_class_driver *class_driver)
203 int minor_base = class_driver->minor_base;
204 char name[BUS_ID_SIZE];
206 #ifdef CONFIG_USB_DYNAMIC_MINORS
210 if (intf->minor == -1)
213 dbg ("removing %d minor", intf->minor);
215 spin_lock (&minor_lock);
216 usb_minors[intf->minor] = NULL;
217 spin_unlock (&minor_lock);
219 snprintf(name, BUS_ID_SIZE, class_driver->name, intf->minor - minor_base);
221 class_simple_device_remove(MKDEV(USB_MAJOR, intf->minor));
222 intf->class_dev = NULL;
225 EXPORT_SYMBOL(usb_deregister_dev);