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 void release_usb_class_dev(struct class_device *class_dev)
71 dbg("%s - %s", __FUNCTION__, class_dev->class_id);
75 static struct class usb_class = {
77 .release = &release_usb_class_dev,
80 int usb_major_init(void)
84 error = register_chrdev(USB_MAJOR, "usb", &usb_fops);
86 err("unable to get major %d for usb devices", USB_MAJOR);
90 error = class_register(&usb_class);
92 err("class_register failed for usb devices");
93 unregister_chrdev(USB_MAJOR, "usb");
103 void usb_major_cleanup(void)
105 class_unregister(&usb_class);
107 unregister_chrdev(USB_MAJOR, "usb");
110 static ssize_t show_dev(struct class_device *class_dev, char *buf)
112 int minor = (int)(long)class_get_devdata(class_dev);
113 return print_dev_t(buf, MKDEV(USB_MAJOR, minor));
115 static CLASS_DEVICE_ATTR(dev, S_IRUGO, show_dev, NULL);
118 * usb_register_dev - register a USB device, and ask for a minor number
119 * @intf: pointer to the usb_interface that is being registered
120 * @class_driver: pointer to the usb_class_driver for this device
122 * This should be called by all USB drivers that use the USB major number.
123 * If CONFIG_USB_DYNAMIC_MINORS is enabled, the minor number will be
124 * dynamically allocated out of the list of available ones. If it is not
125 * enabled, the minor number will be based on the next available free minor,
126 * starting at the class_driver->minor_base.
128 * This function also creates the devfs file for the usb device, if devfs
129 * is enabled, and creates a usb class device in the sysfs tree.
131 * usb_deregister_dev() must be called when the driver is done with
132 * the minor numbers given out by this function.
134 * Returns -EINVAL if something bad happens with trying to register a
135 * device, and 0 on success.
137 int usb_register_dev(struct usb_interface *intf,
138 struct usb_class_driver *class_driver)
140 int retval = -EINVAL;
141 int minor_base = class_driver->minor_base;
143 char name[BUS_ID_SIZE];
144 struct class_device *class_dev;
147 #ifdef CONFIG_USB_DYNAMIC_MINORS
149 * We don't care what the device tries to start at, we want to start
150 * at zero to pack the devices into the smallest available space with
151 * no holes in the minor range.
157 dbg ("looking for a minor, starting at %d", minor_base);
159 if (class_driver->fops == NULL)
162 spin_lock (&minor_lock);
163 for (minor = minor_base; minor < MAX_USB_MINORS; ++minor) {
164 if (usb_minors[minor])
167 usb_minors[minor] = class_driver->fops;
172 spin_unlock (&minor_lock);
179 /* handle the devfs registration */
180 snprintf(name, BUS_ID_SIZE, class_driver->name, minor - minor_base);
181 devfs_mk_cdev(MKDEV(USB_MAJOR, minor), class_driver->mode, name);
183 /* create a usb class device for this usb interface */
184 class_dev = kmalloc(sizeof(*class_dev), GFP_KERNEL);
186 memset(class_dev, 0x00, sizeof(struct class_device));
187 class_dev->class = &usb_class;
188 class_dev->dev = &intf->dev;
190 temp = strrchr(name, '/');
191 if (temp && (temp[1] != 0x00))
195 snprintf(class_dev->class_id, BUS_ID_SIZE, "%s", temp);
196 class_set_devdata(class_dev, (void *)(long)intf->minor);
197 class_device_register(class_dev);
198 class_device_create_file(class_dev, &class_device_attr_dev);
199 intf->class_dev = class_dev;
204 EXPORT_SYMBOL(usb_register_dev);
207 * usb_deregister_dev - deregister a USB device's dynamic minor.
208 * @intf: pointer to the usb_interface that is being deregistered
209 * @class_driver: pointer to the usb_class_driver for this device
211 * Used in conjunction with usb_register_dev(). This function is called
212 * when the USB driver is finished with the minor numbers gotten from a
213 * call to usb_register_dev() (usually when the device is disconnected
216 * This function also cleans up the devfs file for the usb device, if devfs
217 * is enabled, and removes the usb class device from the sysfs tree.
219 * This should be called by all drivers that use the USB major number.
221 void usb_deregister_dev(struct usb_interface *intf,
222 struct usb_class_driver *class_driver)
224 int minor_base = class_driver->minor_base;
225 char name[BUS_ID_SIZE];
227 #ifdef CONFIG_USB_DYNAMIC_MINORS
231 if (intf->minor == -1)
234 dbg ("removing %d minor", intf->minor);
236 spin_lock (&minor_lock);
237 usb_minors[intf->minor] = NULL;
238 spin_unlock (&minor_lock);
240 snprintf(name, BUS_ID_SIZE, class_driver->name, intf->minor - minor_base);
243 if (intf->class_dev) {
244 class_device_unregister(intf->class_dev);
245 intf->class_dev = NULL;
249 EXPORT_SYMBOL(usb_deregister_dev);