11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * drivers/usb/file.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * (C) Copyright Linus Torvalds 1999 51da177e4SLinus Torvalds * (C) Copyright Johannes Erdfelt 1999-2001 61da177e4SLinus Torvalds * (C) Copyright Andreas Gal 1999 71da177e4SLinus Torvalds * (C) Copyright Gregory P. Smith 1999 81da177e4SLinus Torvalds * (C) Copyright Deti Fliegl 1999 (new USB architecture) 91da177e4SLinus Torvalds * (C) Copyright Randy Dunlap 2000 101da177e4SLinus Torvalds * (C) Copyright David Brownell 2000-2001 (kernel hotplug, usb_device_id, 111da177e4SLinus Torvalds more docs, etc) 121da177e4SLinus Torvalds * (C) Copyright Yggdrasil Computing, Inc. 2000 131da177e4SLinus Torvalds * (usb_device_id matching changes by Adam J. Richter) 141da177e4SLinus Torvalds * (C) Copyright Greg Kroah-Hartman 2002-2003 151da177e4SLinus Torvalds * 161da177e4SLinus Torvalds */ 171da177e4SLinus Torvalds 181da177e4SLinus Torvalds #include <linux/config.h> 191da177e4SLinus Torvalds #include <linux/module.h> 201da177e4SLinus Torvalds #include <linux/devfs_fs_kernel.h> 211da177e4SLinus Torvalds #include <linux/spinlock.h> 221da177e4SLinus Torvalds #include <linux/errno.h> 231da177e4SLinus Torvalds 241da177e4SLinus Torvalds #ifdef CONFIG_USB_DEBUG 251da177e4SLinus Torvalds #define DEBUG 261da177e4SLinus Torvalds #else 271da177e4SLinus Torvalds #undef DEBUG 281da177e4SLinus Torvalds #endif 291da177e4SLinus Torvalds #include <linux/usb.h> 301da177e4SLinus Torvalds 316d5e8254SGreg KH #include "usb.h" 326d5e8254SGreg KH 331da177e4SLinus Torvalds #define MAX_USB_MINORS 256 341da177e4SLinus Torvalds static struct file_operations *usb_minors[MAX_USB_MINORS]; 351da177e4SLinus Torvalds static DEFINE_SPINLOCK(minor_lock); 361da177e4SLinus Torvalds 371da177e4SLinus Torvalds static int usb_open(struct inode * inode, struct file * file) 381da177e4SLinus Torvalds { 391da177e4SLinus Torvalds int minor = iminor(inode); 401da177e4SLinus Torvalds struct file_operations *c; 411da177e4SLinus Torvalds int err = -ENODEV; 421da177e4SLinus Torvalds struct file_operations *old_fops, *new_fops = NULL; 431da177e4SLinus Torvalds 441da177e4SLinus Torvalds spin_lock (&minor_lock); 451da177e4SLinus Torvalds c = usb_minors[minor]; 461da177e4SLinus Torvalds 471da177e4SLinus Torvalds if (!c || !(new_fops = fops_get(c))) { 481da177e4SLinus Torvalds spin_unlock(&minor_lock); 491da177e4SLinus Torvalds return err; 501da177e4SLinus Torvalds } 511da177e4SLinus Torvalds spin_unlock(&minor_lock); 521da177e4SLinus Torvalds 531da177e4SLinus Torvalds old_fops = file->f_op; 541da177e4SLinus Torvalds file->f_op = new_fops; 551da177e4SLinus Torvalds /* Curiouser and curiouser... NULL ->open() as "no device" ? */ 561da177e4SLinus Torvalds if (file->f_op->open) 571da177e4SLinus Torvalds err = file->f_op->open(inode,file); 581da177e4SLinus Torvalds if (err) { 591da177e4SLinus Torvalds fops_put(file->f_op); 601da177e4SLinus Torvalds file->f_op = fops_get(old_fops); 611da177e4SLinus Torvalds } 621da177e4SLinus Torvalds fops_put(old_fops); 631da177e4SLinus Torvalds return err; 641da177e4SLinus Torvalds } 651da177e4SLinus Torvalds 661da177e4SLinus Torvalds static struct file_operations usb_fops = { 671da177e4SLinus Torvalds .owner = THIS_MODULE, 681da177e4SLinus Torvalds .open = usb_open, 691da177e4SLinus Torvalds }; 701da177e4SLinus Torvalds 7156b22935Sgregkh@suse.de static struct class *usb_class; 721da177e4SLinus Torvalds 731da177e4SLinus Torvalds int usb_major_init(void) 741da177e4SLinus Torvalds { 751da177e4SLinus Torvalds int error; 761da177e4SLinus Torvalds 771da177e4SLinus Torvalds error = register_chrdev(USB_MAJOR, "usb", &usb_fops); 781da177e4SLinus Torvalds if (error) { 791da177e4SLinus Torvalds err("unable to get major %d for usb devices", USB_MAJOR); 801da177e4SLinus Torvalds goto out; 811da177e4SLinus Torvalds } 821da177e4SLinus Torvalds 8356b22935Sgregkh@suse.de usb_class = class_create(THIS_MODULE, "usb"); 841da177e4SLinus Torvalds if (IS_ERR(usb_class)) { 855cebfb75SMark M. Hoffman error = PTR_ERR(usb_class); 8656b22935Sgregkh@suse.de err("class_create failed for usb devices"); 871da177e4SLinus Torvalds unregister_chrdev(USB_MAJOR, "usb"); 881da177e4SLinus Torvalds goto out; 891da177e4SLinus Torvalds } 901da177e4SLinus Torvalds 911da177e4SLinus Torvalds devfs_mk_dir("usb"); 921da177e4SLinus Torvalds 931da177e4SLinus Torvalds out: 941da177e4SLinus Torvalds return error; 951da177e4SLinus Torvalds } 961da177e4SLinus Torvalds 971da177e4SLinus Torvalds void usb_major_cleanup(void) 981da177e4SLinus Torvalds { 9956b22935Sgregkh@suse.de class_destroy(usb_class); 1001da177e4SLinus Torvalds devfs_remove("usb"); 1011da177e4SLinus Torvalds unregister_chrdev(USB_MAJOR, "usb"); 1021da177e4SLinus Torvalds } 1031da177e4SLinus Torvalds 1041da177e4SLinus Torvalds /** 1051da177e4SLinus Torvalds * usb_register_dev - register a USB device, and ask for a minor number 1061da177e4SLinus Torvalds * @intf: pointer to the usb_interface that is being registered 1071da177e4SLinus Torvalds * @class_driver: pointer to the usb_class_driver for this device 1081da177e4SLinus Torvalds * 1091da177e4SLinus Torvalds * This should be called by all USB drivers that use the USB major number. 1101da177e4SLinus Torvalds * If CONFIG_USB_DYNAMIC_MINORS is enabled, the minor number will be 1111da177e4SLinus Torvalds * dynamically allocated out of the list of available ones. If it is not 1121da177e4SLinus Torvalds * enabled, the minor number will be based on the next available free minor, 1131da177e4SLinus Torvalds * starting at the class_driver->minor_base. 1141da177e4SLinus Torvalds * 1151da177e4SLinus Torvalds * This function also creates the devfs file for the usb device, if devfs 1161da177e4SLinus Torvalds * is enabled, and creates a usb class device in the sysfs tree. 1171da177e4SLinus Torvalds * 1181da177e4SLinus Torvalds * usb_deregister_dev() must be called when the driver is done with 1191da177e4SLinus Torvalds * the minor numbers given out by this function. 1201da177e4SLinus Torvalds * 1211da177e4SLinus Torvalds * Returns -EINVAL if something bad happens with trying to register a 1221da177e4SLinus Torvalds * device, and 0 on success. 1231da177e4SLinus Torvalds */ 1241da177e4SLinus Torvalds int usb_register_dev(struct usb_interface *intf, 1251da177e4SLinus Torvalds struct usb_class_driver *class_driver) 1261da177e4SLinus Torvalds { 1271da177e4SLinus Torvalds int retval = -EINVAL; 1281da177e4SLinus Torvalds int minor_base = class_driver->minor_base; 1291da177e4SLinus Torvalds int minor = 0; 1301da177e4SLinus Torvalds char name[BUS_ID_SIZE]; 1311da177e4SLinus Torvalds char *temp; 1321da177e4SLinus Torvalds 1331da177e4SLinus Torvalds #ifdef CONFIG_USB_DYNAMIC_MINORS 1341da177e4SLinus Torvalds /* 1351da177e4SLinus Torvalds * We don't care what the device tries to start at, we want to start 1361da177e4SLinus Torvalds * at zero to pack the devices into the smallest available space with 1371da177e4SLinus Torvalds * no holes in the minor range. 1381da177e4SLinus Torvalds */ 1391da177e4SLinus Torvalds minor_base = 0; 1401da177e4SLinus Torvalds #endif 1411da177e4SLinus Torvalds intf->minor = -1; 1421da177e4SLinus Torvalds 1431da177e4SLinus Torvalds dbg ("looking for a minor, starting at %d", minor_base); 1441da177e4SLinus Torvalds 1451da177e4SLinus Torvalds if (class_driver->fops == NULL) 1461da177e4SLinus Torvalds goto exit; 1471da177e4SLinus Torvalds 1481da177e4SLinus Torvalds spin_lock (&minor_lock); 1491da177e4SLinus Torvalds for (minor = minor_base; minor < MAX_USB_MINORS; ++minor) { 1501da177e4SLinus Torvalds if (usb_minors[minor]) 1511da177e4SLinus Torvalds continue; 1521da177e4SLinus Torvalds 1531da177e4SLinus Torvalds usb_minors[minor] = class_driver->fops; 1541da177e4SLinus Torvalds 1551da177e4SLinus Torvalds retval = 0; 1561da177e4SLinus Torvalds break; 1571da177e4SLinus Torvalds } 1581da177e4SLinus Torvalds spin_unlock (&minor_lock); 1591da177e4SLinus Torvalds 1601da177e4SLinus Torvalds if (retval) 1611da177e4SLinus Torvalds goto exit; 1621da177e4SLinus Torvalds 1631da177e4SLinus Torvalds intf->minor = minor; 1641da177e4SLinus Torvalds 1651da177e4SLinus Torvalds /* handle the devfs registration */ 1661da177e4SLinus Torvalds snprintf(name, BUS_ID_SIZE, class_driver->name, minor - minor_base); 1671da177e4SLinus Torvalds devfs_mk_cdev(MKDEV(USB_MAJOR, minor), class_driver->mode, name); 1681da177e4SLinus Torvalds 1691da177e4SLinus Torvalds /* create a usb class device for this usb interface */ 1701da177e4SLinus Torvalds temp = strrchr(name, '/'); 1711da177e4SLinus Torvalds if (temp && (temp[1] != 0x00)) 1721da177e4SLinus Torvalds ++temp; 1731da177e4SLinus Torvalds else 1741da177e4SLinus Torvalds temp = name; 175*53f46542SGreg Kroah-Hartman intf->class_dev = class_device_create(usb_class, NULL, 176*53f46542SGreg Kroah-Hartman MKDEV(USB_MAJOR, minor), 177*53f46542SGreg Kroah-Hartman &intf->dev, "%s", temp); 1781da177e4SLinus Torvalds if (IS_ERR(intf->class_dev)) { 1791da177e4SLinus Torvalds spin_lock (&minor_lock); 1801da177e4SLinus Torvalds usb_minors[intf->minor] = NULL; 1811da177e4SLinus Torvalds spin_unlock (&minor_lock); 1821da177e4SLinus Torvalds devfs_remove (name); 1831da177e4SLinus Torvalds retval = PTR_ERR(intf->class_dev); 1841da177e4SLinus Torvalds } 1851da177e4SLinus Torvalds exit: 1861da177e4SLinus Torvalds return retval; 1871da177e4SLinus Torvalds } 1881da177e4SLinus Torvalds EXPORT_SYMBOL(usb_register_dev); 1891da177e4SLinus Torvalds 1901da177e4SLinus Torvalds /** 1911da177e4SLinus Torvalds * usb_deregister_dev - deregister a USB device's dynamic minor. 1921da177e4SLinus Torvalds * @intf: pointer to the usb_interface that is being deregistered 1931da177e4SLinus Torvalds * @class_driver: pointer to the usb_class_driver for this device 1941da177e4SLinus Torvalds * 1951da177e4SLinus Torvalds * Used in conjunction with usb_register_dev(). This function is called 1961da177e4SLinus Torvalds * when the USB driver is finished with the minor numbers gotten from a 1971da177e4SLinus Torvalds * call to usb_register_dev() (usually when the device is disconnected 1981da177e4SLinus Torvalds * from the system.) 1991da177e4SLinus Torvalds * 2001da177e4SLinus Torvalds * This function also cleans up the devfs file for the usb device, if devfs 2011da177e4SLinus Torvalds * is enabled, and removes the usb class device from the sysfs tree. 2021da177e4SLinus Torvalds * 2031da177e4SLinus Torvalds * This should be called by all drivers that use the USB major number. 2041da177e4SLinus Torvalds */ 2051da177e4SLinus Torvalds void usb_deregister_dev(struct usb_interface *intf, 2061da177e4SLinus Torvalds struct usb_class_driver *class_driver) 2071da177e4SLinus Torvalds { 2081da177e4SLinus Torvalds int minor_base = class_driver->minor_base; 2091da177e4SLinus Torvalds char name[BUS_ID_SIZE]; 2101da177e4SLinus Torvalds 2111da177e4SLinus Torvalds #ifdef CONFIG_USB_DYNAMIC_MINORS 2121da177e4SLinus Torvalds minor_base = 0; 2131da177e4SLinus Torvalds #endif 2141da177e4SLinus Torvalds 2151da177e4SLinus Torvalds if (intf->minor == -1) 2161da177e4SLinus Torvalds return; 2171da177e4SLinus Torvalds 2181da177e4SLinus Torvalds dbg ("removing %d minor", intf->minor); 2191da177e4SLinus Torvalds 2201da177e4SLinus Torvalds spin_lock (&minor_lock); 2211da177e4SLinus Torvalds usb_minors[intf->minor] = NULL; 2221da177e4SLinus Torvalds spin_unlock (&minor_lock); 2231da177e4SLinus Torvalds 2241da177e4SLinus Torvalds snprintf(name, BUS_ID_SIZE, class_driver->name, intf->minor - minor_base); 2251da177e4SLinus Torvalds devfs_remove (name); 22656b22935Sgregkh@suse.de class_device_destroy(usb_class, MKDEV(USB_MAJOR, intf->minor)); 2271da177e4SLinus Torvalds intf->class_dev = NULL; 2281da177e4SLinus Torvalds intf->minor = -1; 2291da177e4SLinus Torvalds } 2301da177e4SLinus Torvalds EXPORT_SYMBOL(usb_deregister_dev); 2311da177e4SLinus Torvalds 2321da177e4SLinus Torvalds 233