Greg Kroah-Hartman | aa1f3bb | 2017-11-03 09:18:41 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | /* |
Uwe Zeisberger | f30c226 | 2006-10-03 23:01:26 +0200 | [diff] [blame] | 3 | * drivers/usb/core/file.c |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4 | * |
| 5 | * (C) Copyright Linus Torvalds 1999 |
| 6 | * (C) Copyright Johannes Erdfelt 1999-2001 |
| 7 | * (C) Copyright Andreas Gal 1999 |
| 8 | * (C) Copyright Gregory P. Smith 1999 |
| 9 | * (C) Copyright Deti Fliegl 1999 (new USB architecture) |
| 10 | * (C) Copyright Randy Dunlap 2000 |
| 11 | * (C) Copyright David Brownell 2000-2001 (kernel hotplug, usb_device_id, |
Matthias Beyer | 469271f | 2013-10-10 23:41:27 +0200 | [diff] [blame] | 12 | * more docs, etc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | * (C) Copyright Yggdrasil Computing, Inc. 2000 |
| 14 | * (usb_device_id matching changes by Adam J. Richter) |
| 15 | * (C) Copyright Greg Kroah-Hartman 2002-2003 |
| 16 | * |
Greg Kroah-Hartman | b65fba3 | 2016-10-28 17:16:36 -0400 | [diff] [blame] | 17 | * Released under the GPLv2 only. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | */ |
| 19 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | #include <linux/module.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | #include <linux/errno.h> |
Alan Stern | d4ead16 | 2007-05-22 11:46:41 -0400 | [diff] [blame] | 22 | #include <linux/rwsem.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 23 | #include <linux/slab.h> |
Andy Shevchenko | f8868ed | 2015-12-10 16:49:14 +0200 | [diff] [blame] | 24 | #include <linux/string.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | #include <linux/usb.h> |
| 26 | |
Greg KH | 6d5e825 | 2005-04-18 17:39:24 -0700 | [diff] [blame] | 27 | #include "usb.h" |
| 28 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | #define MAX_USB_MINORS 256 |
Arjan van de Ven | 99ac48f | 2006-03-28 01:56:41 -0800 | [diff] [blame] | 30 | static const struct file_operations *usb_minors[MAX_USB_MINORS]; |
Alan Stern | d4ead16 | 2007-05-22 11:46:41 -0400 | [diff] [blame] | 31 | static DECLARE_RWSEM(minor_rwsem); |
Ajay Kaher | 2f86a96 | 2017-03-28 08:09:32 -0400 | [diff] [blame] | 32 | static DEFINE_MUTEX(init_usb_class_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | |
Matthias Beyer | 1335f2d | 2013-10-10 23:41:28 +0200 | [diff] [blame] | 34 | static int usb_open(struct inode *inode, struct file *file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | int err = -ENODEV; |
Al Viro | e84f9e5 | 2013-09-22 14:17:15 -0400 | [diff] [blame] | 37 | const struct file_operations *new_fops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | |
Alan Stern | d4ead16 | 2007-05-22 11:46:41 -0400 | [diff] [blame] | 39 | down_read(&minor_rwsem); |
Al Viro | e84f9e5 | 2013-09-22 14:17:15 -0400 | [diff] [blame] | 40 | new_fops = fops_get(usb_minors[iminor(inode)]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | |
Al Viro | e84f9e5 | 2013-09-22 14:17:15 -0400 | [diff] [blame] | 42 | if (!new_fops) |
Alan Stern | d4ead16 | 2007-05-22 11:46:41 -0400 | [diff] [blame] | 43 | goto done; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | |
Al Viro | e84f9e5 | 2013-09-22 14:17:15 -0400 | [diff] [blame] | 45 | replace_fops(file, new_fops); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | /* Curiouser and curiouser... NULL ->open() as "no device" ? */ |
| 47 | if (file->f_op->open) |
Matthias Beyer | 469271f | 2013-10-10 23:41:27 +0200 | [diff] [blame] | 48 | err = file->f_op->open(inode, file); |
Alan Stern | d4ead16 | 2007-05-22 11:46:41 -0400 | [diff] [blame] | 49 | done: |
| 50 | up_read(&minor_rwsem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | return err; |
| 52 | } |
| 53 | |
Luiz Fernando N. Capitulino | 066202d | 2006-08-05 20:37:11 -0300 | [diff] [blame] | 54 | static const struct file_operations usb_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | .owner = THIS_MODULE, |
| 56 | .open = usb_open, |
Arnd Bergmann | 6038f37 | 2010-08-15 18:52:59 +0200 | [diff] [blame] | 57 | .llseek = noop_llseek, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | }; |
| 59 | |
Greg Kroah-Hartman | 43104f1 | 2006-06-20 15:14:07 -0700 | [diff] [blame] | 60 | static struct usb_class { |
| 61 | struct kref kref; |
| 62 | struct class *class; |
| 63 | } *usb_class; |
| 64 | |
Al Viro | 2c9ede5 | 2011-07-23 20:24:48 -0400 | [diff] [blame] | 65 | static char *usb_devnode(struct device *dev, umode_t *mode) |
Kay Sievers | f7a386c | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 66 | { |
| 67 | struct usb_class_driver *drv; |
| 68 | |
| 69 | drv = dev_get_drvdata(dev); |
Kay Sievers | e454cea | 2009-09-18 23:01:12 +0200 | [diff] [blame] | 70 | if (!drv || !drv->devnode) |
Kay Sievers | f7a386c | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 71 | return NULL; |
Kay Sievers | e454cea | 2009-09-18 23:01:12 +0200 | [diff] [blame] | 72 | return drv->devnode(dev, mode); |
Kay Sievers | f7a386c | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 73 | } |
| 74 | |
Greg Kroah-Hartman | 43104f1 | 2006-06-20 15:14:07 -0700 | [diff] [blame] | 75 | static int init_usb_class(void) |
| 76 | { |
| 77 | int result = 0; |
| 78 | |
| 79 | if (usb_class != NULL) { |
| 80 | kref_get(&usb_class->kref); |
| 81 | goto exit; |
| 82 | } |
| 83 | |
| 84 | usb_class = kmalloc(sizeof(*usb_class), GFP_KERNEL); |
| 85 | if (!usb_class) { |
| 86 | result = -ENOMEM; |
| 87 | goto exit; |
| 88 | } |
| 89 | |
| 90 | kref_init(&usb_class->kref); |
Greg Kroah-Hartman | 7e97243 | 2012-04-25 17:22:37 -0700 | [diff] [blame] | 91 | usb_class->class = class_create(THIS_MODULE, "usbmisc"); |
Greg Kroah-Hartman | 43104f1 | 2006-06-20 15:14:07 -0700 | [diff] [blame] | 92 | if (IS_ERR(usb_class->class)) { |
Alexey Khoroshilov | de5535f | 2013-06-06 01:27:15 +0400 | [diff] [blame] | 93 | result = PTR_ERR(usb_class->class); |
Greg Kroah-Hartman | 69a8594 | 2008-08-14 09:37:34 -0700 | [diff] [blame] | 94 | printk(KERN_ERR "class_create failed for usb devices\n"); |
Greg Kroah-Hartman | 43104f1 | 2006-06-20 15:14:07 -0700 | [diff] [blame] | 95 | kfree(usb_class); |
| 96 | usb_class = NULL; |
Dan Carpenter | ed7487c | 2009-11-10 11:02:08 +0200 | [diff] [blame] | 97 | goto exit; |
Greg Kroah-Hartman | 43104f1 | 2006-06-20 15:14:07 -0700 | [diff] [blame] | 98 | } |
Kay Sievers | e454cea | 2009-09-18 23:01:12 +0200 | [diff] [blame] | 99 | usb_class->class->devnode = usb_devnode; |
Greg Kroah-Hartman | 43104f1 | 2006-06-20 15:14:07 -0700 | [diff] [blame] | 100 | |
| 101 | exit: |
| 102 | return result; |
| 103 | } |
| 104 | |
| 105 | static void release_usb_class(struct kref *kref) |
| 106 | { |
| 107 | /* Ok, we cheat as we know we only have one usb_class */ |
| 108 | class_destroy(usb_class->class); |
| 109 | kfree(usb_class); |
| 110 | usb_class = NULL; |
| 111 | } |
| 112 | |
| 113 | static void destroy_usb_class(void) |
| 114 | { |
Ajay Kaher | 2f86a96 | 2017-03-28 08:09:32 -0400 | [diff] [blame] | 115 | mutex_lock(&init_usb_class_mutex); |
| 116 | kref_put(&usb_class->kref, release_usb_class); |
| 117 | mutex_unlock(&init_usb_class_mutex); |
Greg Kroah-Hartman | 43104f1 | 2006-06-20 15:14:07 -0700 | [diff] [blame] | 118 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | |
| 120 | int usb_major_init(void) |
| 121 | { |
| 122 | int error; |
| 123 | |
| 124 | error = register_chrdev(USB_MAJOR, "usb", &usb_fops); |
Greg Kroah-Hartman | 43104f1 | 2006-06-20 15:14:07 -0700 | [diff] [blame] | 125 | if (error) |
Greg Kroah-Hartman | 69a8594 | 2008-08-14 09:37:34 -0700 | [diff] [blame] | 126 | printk(KERN_ERR "Unable to get major %d for usb devices\n", |
| 127 | USB_MAJOR); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | return error; |
| 130 | } |
| 131 | |
| 132 | void usb_major_cleanup(void) |
| 133 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | unregister_chrdev(USB_MAJOR, "usb"); |
| 135 | } |
| 136 | |
| 137 | /** |
| 138 | * usb_register_dev - register a USB device, and ask for a minor number |
| 139 | * @intf: pointer to the usb_interface that is being registered |
| 140 | * @class_driver: pointer to the usb_class_driver for this device |
| 141 | * |
| 142 | * This should be called by all USB drivers that use the USB major number. |
| 143 | * If CONFIG_USB_DYNAMIC_MINORS is enabled, the minor number will be |
| 144 | * dynamically allocated out of the list of available ones. If it is not |
| 145 | * enabled, the minor number will be based on the next available free minor, |
| 146 | * starting at the class_driver->minor_base. |
| 147 | * |
Greg Kroah-Hartman | d6e5bcf | 2005-06-20 21:15:16 -0700 | [diff] [blame] | 148 | * This function also creates a usb class device in the sysfs tree. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | * |
| 150 | * usb_deregister_dev() must be called when the driver is done with |
| 151 | * the minor numbers given out by this function. |
| 152 | * |
Yacine Belkadi | 626f090 | 2013-08-02 20:10:04 +0200 | [diff] [blame] | 153 | * Return: -EINVAL if something bad happens with trying to register a |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | * device, and 0 on success. |
| 155 | */ |
| 156 | int usb_register_dev(struct usb_interface *intf, |
| 157 | struct usb_class_driver *class_driver) |
| 158 | { |
Alan Stern | 0026e00 | 2010-09-21 15:01:53 -0400 | [diff] [blame] | 159 | int retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 160 | int minor_base = class_driver->minor_base; |
Alan Stern | 0026e00 | 2010-09-21 15:01:53 -0400 | [diff] [blame] | 161 | int minor; |
Kay Sievers | 7071a3c | 2008-05-02 06:02:41 +0200 | [diff] [blame] | 162 | char name[20]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | |
| 164 | #ifdef CONFIG_USB_DYNAMIC_MINORS |
Matthias Beyer | 469271f | 2013-10-10 23:41:27 +0200 | [diff] [blame] | 165 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | * We don't care what the device tries to start at, we want to start |
| 167 | * at zero to pack the devices into the smallest available space with |
| 168 | * no holes in the minor range. |
| 169 | */ |
| 170 | minor_base = 0; |
| 171 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 172 | |
| 173 | if (class_driver->fops == NULL) |
Alan Stern | 0026e00 | 2010-09-21 15:01:53 -0400 | [diff] [blame] | 174 | return -EINVAL; |
| 175 | if (intf->minor >= 0) |
| 176 | return -EADDRINUSE; |
| 177 | |
Ajay Kaher | 2f86a96 | 2017-03-28 08:09:32 -0400 | [diff] [blame] | 178 | mutex_lock(&init_usb_class_mutex); |
Alan Stern | 0026e00 | 2010-09-21 15:01:53 -0400 | [diff] [blame] | 179 | retval = init_usb_class(); |
Ajay Kaher | 2f86a96 | 2017-03-28 08:09:32 -0400 | [diff] [blame] | 180 | mutex_unlock(&init_usb_class_mutex); |
| 181 | |
Alan Stern | 0026e00 | 2010-09-21 15:01:53 -0400 | [diff] [blame] | 182 | if (retval) |
| 183 | return retval; |
| 184 | |
Greg Kroah-Hartman | 079d440 | 2012-05-01 21:33:35 -0700 | [diff] [blame] | 185 | dev_dbg(&intf->dev, "looking for a minor, starting at %d\n", minor_base); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | |
Alan Stern | d4ead16 | 2007-05-22 11:46:41 -0400 | [diff] [blame] | 187 | down_write(&minor_rwsem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | for (minor = minor_base; minor < MAX_USB_MINORS; ++minor) { |
| 189 | if (usb_minors[minor]) |
| 190 | continue; |
| 191 | |
| 192 | usb_minors[minor] = class_driver->fops; |
Alan Stern | 0026e00 | 2010-09-21 15:01:53 -0400 | [diff] [blame] | 193 | intf->minor = minor; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 194 | break; |
| 195 | } |
Alan Stern | 303911c | 2019-08-12 16:11:07 -0400 | [diff] [blame] | 196 | if (intf->minor < 0) { |
| 197 | up_write(&minor_rwsem); |
Alan Stern | 0026e00 | 2010-09-21 15:01:53 -0400 | [diff] [blame] | 198 | return -EXFULL; |
Alan Stern | 303911c | 2019-08-12 16:11:07 -0400 | [diff] [blame] | 199 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 201 | /* create a usb class device for this usb interface */ |
Kay Sievers | 7071a3c | 2008-05-02 06:02:41 +0200 | [diff] [blame] | 202 | snprintf(name, sizeof(name), class_driver->name, minor - minor_base); |
Greg Kroah-Hartman | b0b090e | 2008-07-21 20:03:34 -0700 | [diff] [blame] | 203 | intf->usb_dev = device_create(usb_class->class, &intf->dev, |
Kay Sievers | f7a386c | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 204 | MKDEV(USB_MAJOR, minor), class_driver, |
Andy Shevchenko | f8868ed | 2015-12-10 16:49:14 +0200 | [diff] [blame] | 205 | "%s", kbasename(name)); |
Greg Kroah-Hartman | 0873c76 | 2006-06-20 13:09:50 -0700 | [diff] [blame] | 206 | if (IS_ERR(intf->usb_dev)) { |
Alan Stern | 0026e00 | 2010-09-21 15:01:53 -0400 | [diff] [blame] | 207 | usb_minors[minor] = NULL; |
| 208 | intf->minor = -1; |
Greg Kroah-Hartman | 0873c76 | 2006-06-20 13:09:50 -0700 | [diff] [blame] | 209 | retval = PTR_ERR(intf->usb_dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 210 | } |
Alan Stern | 303911c | 2019-08-12 16:11:07 -0400 | [diff] [blame] | 211 | up_write(&minor_rwsem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | return retval; |
| 213 | } |
Greg Kroah-Hartman | 782e70c | 2008-01-25 11:12:21 -0600 | [diff] [blame] | 214 | EXPORT_SYMBOL_GPL(usb_register_dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | |
| 216 | /** |
| 217 | * usb_deregister_dev - deregister a USB device's dynamic minor. |
| 218 | * @intf: pointer to the usb_interface that is being deregistered |
| 219 | * @class_driver: pointer to the usb_class_driver for this device |
| 220 | * |
| 221 | * Used in conjunction with usb_register_dev(). This function is called |
| 222 | * when the USB driver is finished with the minor numbers gotten from a |
| 223 | * call to usb_register_dev() (usually when the device is disconnected |
| 224 | * from the system.) |
| 225 | * |
Greg Kroah-Hartman | d6e5bcf | 2005-06-20 21:15:16 -0700 | [diff] [blame] | 226 | * This function also removes the usb class device from the sysfs tree. |
| 227 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 228 | * This should be called by all drivers that use the USB major number. |
| 229 | */ |
| 230 | void usb_deregister_dev(struct usb_interface *intf, |
| 231 | struct usb_class_driver *class_driver) |
| 232 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 233 | if (intf->minor == -1) |
| 234 | return; |
| 235 | |
Greg Kroah-Hartman | 079d440 | 2012-05-01 21:33:35 -0700 | [diff] [blame] | 236 | dev_dbg(&intf->dev, "removing %d minor\n", intf->minor); |
Alan Stern | 303911c | 2019-08-12 16:11:07 -0400 | [diff] [blame] | 237 | device_destroy(usb_class->class, MKDEV(USB_MAJOR, intf->minor)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | |
Alan Stern | d4ead16 | 2007-05-22 11:46:41 -0400 | [diff] [blame] | 239 | down_write(&minor_rwsem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | usb_minors[intf->minor] = NULL; |
Alan Stern | d4ead16 | 2007-05-22 11:46:41 -0400 | [diff] [blame] | 241 | up_write(&minor_rwsem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | |
Greg Kroah-Hartman | 0873c76 | 2006-06-20 13:09:50 -0700 | [diff] [blame] | 243 | intf->usb_dev = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 244 | intf->minor = -1; |
Greg Kroah-Hartman | 43104f1 | 2006-06-20 15:14:07 -0700 | [diff] [blame] | 245 | destroy_usb_class(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | } |
Greg Kroah-Hartman | 782e70c | 2008-01-25 11:12:21 -0600 | [diff] [blame] | 247 | EXPORT_SYMBOL_GPL(usb_deregister_dev); |