drivers/usb/core/driver.c

   1 /*
   2  * drivers/usb/driver.c - most of the driver model stuff for usb
   3  *
   4  * (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de>
   5  *
   6  * based on drivers/usb/usb.c which had the following copyrights:
   7  *      (C) Copyright Linus Torvalds 1999
   8  *      (C) Copyright Johannes Erdfelt 1999-2001
   9  *      (C) Copyright Andreas Gal 1999
  10  *      (C) Copyright Gregory P. Smith 1999
  11  *      (C) Copyright Deti Fliegl 1999 (new USB architecture)
  12  *      (C) Copyright Randy Dunlap 2000
  13  *      (C) Copyright David Brownell 2000-2004
  14  *      (C) Copyright Yggdrasil Computing, Inc. 2000
  15  *              (usb_device_id matching changes by Adam J. Richter)
  16  *      (C) Copyright Greg Kroah-Hartman 2002-2003
  17  *
  18  * NOTE! This is not actually a driver at all, rather this is
  19  * just a collection of helper routines that implement the
  20  * generic USB things that the real drivers can use..
  21  *
  22  */
  23
  24 #include <linux/device.h>
  25 #include <linux/usb.h>
  26 #include "hcd.h"
  27 #include "usb.h"
  28
  29 static int usb_match_one_id(struct usb_interface *interface,
  30                             const struct usb_device_id *id);
  31
  32 struct usb_dynid {
  33         struct list_head node;
  34         struct usb_device_id id;
  35 };
  36
  37
  38 static int generic_probe(struct device *dev)
  39 {
  40         return 0;
  41 }
  42 static int generic_remove(struct device *dev)
  43 {
  44         struct usb_device *udev = to_usb_device(dev);
  45
  46         /* if this is only an unbind, not a physical disconnect, then
  47          * unconfigure the device */
  48         if (udev->state == USB_STATE_CONFIGURED)
  49                 usb_set_configuration(udev, 0);
  50
  51         /* in case the call failed or the device was suspended */
  52         if (udev->state >= USB_STATE_CONFIGURED)
  53                 usb_disable_device(udev, 0);
  54         return 0;
  55 }
  56
  57 struct device_driver usb_generic_driver = {
  58         .owner = THIS_MODULE,
  59         .name = "usb",
  60         .bus = &usb_bus_type,
  61         .probe = generic_probe,
  62         .remove = generic_remove,
  63 };
  64
  65 /* Fun hack to determine if the struct device is a
  66  * usb device or a usb interface. */
  67 int usb_generic_driver_data;
  68
  69 #ifdef CONFIG_HOTPLUG
  70
  71 /*
  72  * Adds a new dynamic USBdevice ID to this driver,
  73  * and cause the driver to probe for all devices again.
  74  */
  75 static ssize_t store_new_id(struct device_driver *driver,
  76                             const char *buf, size_t count)
  77 {
  78         struct usb_driver *usb_drv = to_usb_driver(driver);
  79         struct usb_dynid *dynid;
  80         u32 idVendor = 0;
  81         u32 idProduct = 0;
  82         int fields = 0;
  83
  84         fields = sscanf(buf, "%x %x", &idVendor, &idProduct);
  85         if (fields < 2)
  86                 return -EINVAL;
  87
  88         dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
  89         if (!dynid)
  90                 return -ENOMEM;
  91
  92         INIT_LIST_HEAD(&dynid->node);
  93         dynid->id.idVendor = idVendor;
  94         dynid->id.idProduct = idProduct;
  95         dynid->id.match_flags = USB_DEVICE_ID_MATCH_DEVICE;
  96
  97         spin_lock(&usb_drv->dynids.lock);
  98         list_add_tail(&usb_drv->dynids.list, &dynid->node);
  99         spin_unlock(&usb_drv->dynids.lock);
 100
 101         if (get_driver(driver)) {
 102                 driver_attach(driver);
 103                 put_driver(driver);
 104         }
 105
 106         return count;
 107 }
 108 static DRIVER_ATTR(new_id, S_IWUSR, NULL, store_new_id);
 109
 110 static int usb_create_newid_file(struct usb_driver *usb_drv)
 111 {
 112         int error = 0;
 113
 114         if (usb_drv->no_dynamic_id)
 115                 goto exit;
 116
 117         if (usb_drv->probe != NULL)
 118                 error = sysfs_create_file(&usb_drv->driver.kobj,
 119                                           &driver_attr_new_id.attr);
 120 exit:
 121         return error;
 122 }
 123
 124 static void usb_remove_newid_file(struct usb_driver *usb_drv)
 125 {
 126         if (usb_drv->no_dynamic_id)
 127                 return;
 128
 129         if (usb_drv->probe != NULL)
 130                 sysfs_remove_file(&usb_drv->driver.kobj,
 131                                   &driver_attr_new_id.attr);
 132 }
 133
 134 static void usb_free_dynids(struct usb_driver *usb_drv)
 135 {
 136         struct usb_dynid *dynid, *n;
 137
 138         spin_lock(&usb_drv->dynids.lock);
 139         list_for_each_entry_safe(dynid, n, &usb_drv->dynids.list, node) {
 140                 list_del(&dynid->node);
 141                 kfree(dynid);
 142         }
 143         spin_unlock(&usb_drv->dynids.lock);
 144 }
 145 #else
 146 static inline int usb_create_newid_file(struct usb_driver *usb_drv)
 147 {
 148         return 0;
 149 }
 150
 151 static void usb_remove_newid_file(struct usb_driver *usb_drv)
 152 {
 153 }
 154
 155 static inline void usb_free_dynids(struct usb_driver *usb_drv)
 156 {
 157 }
 158 #endif
 159
 160 static const struct usb_device_id *usb_match_dynamic_id(struct usb_interface *intf,
 161                                                         struct usb_driver *drv)
 162 {
 163         struct usb_dynid *dynid;
 164
 165         spin_lock(&drv->dynids.lock);
 166         list_for_each_entry(dynid, &drv->dynids.list, node) {
 167                 if (usb_match_one_id(intf, &dynid->id)) {
 168                         spin_unlock(&drv->dynids.lock);
 169                         return &dynid->id;
 170                 }
 171         }
 172         spin_unlock(&drv->dynids.lock);
 173         return NULL;
 174 }
 175
 176
 177 /* called from driver core with usb_bus_type.subsys writelock */
 178 static int usb_probe_interface(struct device *dev)
 179 {
 180         struct usb_interface * intf = to_usb_interface(dev);
 181         struct usb_driver * driver = to_usb_driver(dev->driver);
 182         const struct usb_device_id *id;
 183         int error = -ENODEV;
 184
 185         dev_dbg(dev, "%s\n", __FUNCTION__);
 186
 187         if (!driver->probe)
 188                 return error;
 189         /* FIXME we'd much prefer to just resume it ... */
 190         if (interface_to_usbdev(intf)->state == USB_STATE_SUSPENDED)
 191                 return -EHOSTUNREACH;
 192
 193         id = usb_match_id(intf, driver->id_table);
 194         if (!id)
 195                 id = usb_match_dynamic_id(intf, driver);
 196         if (id) {
 197                 dev_dbg(dev, "%s - got id\n", __FUNCTION__);
 198
 199                 /* Interface "power state" doesn't correspond to any hardware
 200                  * state whatsoever.  We use it to record when it's bound to
 201                  * a driver that may start I/0:  it's not frozen/quiesced.
 202                  */
 203                 mark_active(intf);
 204                 intf->condition = USB_INTERFACE_BINDING;
 205                 error = driver->probe(intf, id);
 206                 if (error) {
 207                         mark_quiesced(intf);
 208                         intf->condition = USB_INTERFACE_UNBOUND;
 209                 } else
 210                         intf->condition = USB_INTERFACE_BOUND;
 211         }
 212
 213         return error;
 214 }
 215
 216 /* called from driver core with usb_bus_type.subsys writelock */
 217 static int usb_unbind_interface(struct device *dev)
 218 {
 219         struct usb_interface *intf = to_usb_interface(dev);
 220         struct usb_driver *driver = to_usb_driver(intf->dev.driver);
 221
 222         intf->condition = USB_INTERFACE_UNBINDING;
 223
 224         /* release all urbs for this interface */
 225         usb_disable_interface(interface_to_usbdev(intf), intf);
 226
 227         if (driver && driver->disconnect)
 228                 driver->disconnect(intf);
 229
 230         /* reset other interface state */
 231         usb_set_interface(interface_to_usbdev(intf),
 232                         intf->altsetting[0].desc.bInterfaceNumber,
 233                         0);
 234         usb_set_intfdata(intf, NULL);
 235         intf->condition = USB_INTERFACE_UNBOUND;
 236         mark_quiesced(intf);
 237
 238         return 0;
 239 }
 240
 241 /* returns 0 if no match, 1 if match */
 242 static int usb_match_one_id(struct usb_interface *interface,
 243                             const struct usb_device_id *id)
 244 {
 245         struct usb_host_interface *intf;
 246         struct usb_device *dev;
 247
 248         /* proc_connectinfo in devio.c may call us with id == NULL. */
 249         if (id == NULL)
 250                 return 0;
 251
 252         intf = interface->cur_altsetting;
 253         dev = interface_to_usbdev(interface);
 254
 255         if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
 256             id->idVendor != le16_to_cpu(dev->descriptor.idVendor))
 257                 return 0;
 258
 259         if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
 260             id->idProduct != le16_to_cpu(dev->descriptor.idProduct))
 261                 return 0;
 262
 263         /* No need to test id->bcdDevice_lo != 0, since 0 is never
 264            greater than any unsigned number. */
 265         if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
 266             (id->bcdDevice_lo > le16_to_cpu(dev->descriptor.bcdDevice)))
 267                 return 0;
 268
 269         if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
 270             (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
 271                 return 0;
 272
 273         if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
 274             (id->bDeviceClass != dev->descriptor.bDeviceClass))
 275                 return 0;
 276
 277         if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
 278             (id->bDeviceSubClass!= dev->descriptor.bDeviceSubClass))
 279                 return 0;
 280
 281         if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
 282             (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
 283                 return 0;
 284
 285         if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
 286             (id->bInterfaceClass != intf->desc.bInterfaceClass))
 287                 return 0;
 288
 289         if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
 290             (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
 291                 return 0;
 292
 293         if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
 294             (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
 295                 return 0;
 296
 297         return 1;
 298 }
 299 /**
 300  * usb_match_id - find first usb_device_id matching device or interface
 301  * @interface: the interface of interest
 302  * @id: array of usb_device_id structures, terminated by zero entry
 303  *
 304  * usb_match_id searches an array of usb_device_id's and returns
 305  * the first one matching the device or interface, or null.
 306  * This is used when binding (or rebinding) a driver to an interface.
 307  * Most USB device drivers will use this indirectly, through the usb core,
 308  * but some layered driver frameworks use it directly.
 309  * These device tables are exported with MODULE_DEVICE_TABLE, through
 310  * modutils, to support the driver loading functionality of USB hotplugging.
 311  *
 312  * What Matches:
 313  *
 314  * The "match_flags" element in a usb_device_id controls which
 315  * members are used.  If the corresponding bit is set, the
 316  * value in the device_id must match its corresponding member
 317  * in the device or interface descriptor, or else the device_id
 318  * does not match.
 319  *
 320  * "driver_info" is normally used only by device drivers,
 321  * but you can create a wildcard "matches anything" usb_device_id
 322  * as a driver's "modules.usbmap" entry if you provide an id with
 323  * only a nonzero "driver_info" field.  If you do this, the USB device
 324  * driver's probe() routine should use additional intelligence to
 325  * decide whether to bind to the specified interface.
 326  *
 327  * What Makes Good usb_device_id Tables:
 328  *
 329  * The match algorithm is very simple, so that intelligence in
 330  * driver selection must come from smart driver id records.
 331  * Unless you have good reasons to use another selection policy,
 332  * provide match elements only in related groups, and order match
 333  * specifiers from specific to general.  Use the macros provided
 334  * for that purpose if you can.
 335  *
 336  * The most specific match specifiers use device descriptor
 337  * data.  These are commonly used with product-specific matches;
 338  * the USB_DEVICE macro lets you provide vendor and product IDs,
 339  * and you can also match against ranges of product revisions.
 340  * These are widely used for devices with application or vendor
 341  * specific bDeviceClass values.
 342  *
 343  * Matches based on device class/subclass/protocol specifications
 344  * are slightly more general; use the USB_DEVICE_INFO macro, or
 345  * its siblings.  These are used with single-function devices
 346  * where bDeviceClass doesn't specify that each interface has
 347  * its own class.
 348  *
 349  * Matches based on interface class/subclass/protocol are the
 350  * most general; they let drivers bind to any interface on a
 351  * multiple-function device.  Use the USB_INTERFACE_INFO
 352  * macro, or its siblings, to match class-per-interface style
 353  * devices (as recorded in bDeviceClass).
 354  *
 355  * Within those groups, remember that not all combinations are
 356  * meaningful.  For example, don't give a product version range
 357  * without vendor and product IDs; or specify a protocol without
 358  * its associated class and subclass.
 359  */
 360 const struct usb_device_id *usb_match_id(struct usb_interface *interface,
 361                                          const struct usb_device_id *id)
 362 {
 363         /* proc_connectinfo in devio.c may call us with id == NULL. */
 364         if (id == NULL)
 365                 return NULL;
 366
 367         /* It is important to check that id->driver_info is nonzero,
 368            since an entry that is all zeroes except for a nonzero
 369            id->driver_info is the way to create an entry that
 370            indicates that the driver want to examine every
 371            device and interface. */
 372         for (; id->idVendor || id->bDeviceClass || id->bInterfaceClass ||
 373                id->driver_info; id++) {
 374                 if (usb_match_one_id(interface, id))
 375                         return id;
 376         }
 377
 378         return NULL;
 379 }
 380 EXPORT_SYMBOL_GPL_FUTURE(usb_match_id);
 381
 382 int usb_device_match(struct device *dev, struct device_driver *drv)
 383 {
 384         struct usb_interface *intf;
 385         struct usb_driver *usb_drv;
 386         const struct usb_device_id *id;
 387
 388         /* check for generic driver, which we don't match any device with */
 389         if (drv == &usb_generic_driver)
 390                 return 0;
 391
 392         intf = to_usb_interface(dev);
 393         usb_drv = to_usb_driver(drv);
 394
 395         id = usb_match_id(intf, usb_drv->id_table);
 396         if (id)
 397                 return 1;
 398
 399         id = usb_match_dynamic_id(intf, usb_drv);
 400         if (id)
 401                 return 1;
 402         return 0;
 403 }
 404
 405 /**
 406  * usb_register_driver - register a USB driver
 407  * @new_driver: USB operations for the driver
 408  * @owner: module owner of this driver.
 409  *
 410  * Registers a USB driver with the USB core.  The list of unattached
 411  * interfaces will be rescanned whenever a new driver is added, allowing
 412  * the new driver to attach to any recognized devices.
 413  * Returns a negative error code on failure and 0 on success.
 414  *
 415  * NOTE: if you want your driver to use the USB major number, you must call
 416  * usb_register_dev() to enable that functionality.  This function no longer
 417  * takes care of that.
 418  */
 419 int usb_register_driver(struct usb_driver *new_driver, struct module *owner)
 420 {
 421         int retval = 0;
 422
 423         if (usb_disabled())
 424                 return -ENODEV;
 425
 426         new_driver->driver.name = (char *)new_driver->name;
 427         new_driver->driver.bus = &usb_bus_type;
 428         new_driver->driver.probe = usb_probe_interface;
 429         new_driver->driver.remove = usb_unbind_interface;
 430         new_driver->driver.owner = owner;
 431         spin_lock_init(&new_driver->dynids.lock);
 432         INIT_LIST_HEAD(&new_driver->dynids.list);
 433
 434         retval = driver_register(&new_driver->driver);
 435
 436         if (!retval) {
 437                 pr_info("%s: registered new driver %s\n",
 438                         usbcore_name, new_driver->name);
 439                 usbfs_update_special();
 440                 usb_create_newid_file(new_driver);
 441         } else {
 442                 printk(KERN_ERR "%s: error %d registering driver %s\n",
 443                         usbcore_name, retval, new_driver->name);
 444         }
 445
 446         return retval;
 447 }
 448 EXPORT_SYMBOL_GPL_FUTURE(usb_register_driver);
 449
 450 /**
 451  * usb_deregister - unregister a USB driver
 452  * @driver: USB operations of the driver to unregister
 453  * Context: must be able to sleep
 454  *
 455  * Unlinks the specified driver from the internal USB driver list.
 456  *
 457  * NOTE: If you called usb_register_dev(), you still need to call
 458  * usb_deregister_dev() to clean up your driver's allocated minor numbers,
 459  * this * call will no longer do it for you.
 460  */
 461 void usb_deregister(struct usb_driver *driver)
 462 {
 463         pr_info("%s: deregistering driver %s\n", usbcore_name, driver->name);
 464
 465         usb_remove_newid_file(driver);
 466         usb_free_dynids(driver);
 467         driver_unregister(&driver->driver);
 468
 469         usbfs_update_special();
 470 }
 471 EXPORT_SYMBOL_GPL_FUTURE(usb_deregister);