1 /* 2 * drivers/usb/core/usb.c 3 * 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 2000-2004 11 * (C) Copyright Yggdrasil Computing, Inc. 2000 12 * (usb_device_id matching changes by Adam J. Richter) 13 * (C) Copyright Greg Kroah-Hartman 2002-2003 14 * 15 * NOTE! This is not actually a driver at all, rather this is 16 * just a collection of helper routines that implement the 17 * generic USB things that the real drivers can use.. 18 * 19 * Think of this as a "USB library" rather than anything else. 20 * It should be considered a slave, with no callbacks. Callbacks 21 * are evil. 22 */ 23 24 #include <linux/module.h> 25 #include <linux/moduleparam.h> 26 #include <linux/string.h> 27 #include <linux/bitops.h> 28 #include <linux/slab.h> 29 #include <linux/interrupt.h> /* for in_interrupt() */ 30 #include <linux/kmod.h> 31 #include <linux/init.h> 32 #include <linux/spinlock.h> 33 #include <linux/errno.h> 34 #include <linux/usb.h> 35 #include <linux/usb/hcd.h> 36 #include <linux/mutex.h> 37 #include <linux/workqueue.h> 38 #include <linux/debugfs.h> 39 #include <linux/usb/of.h> 40 41 #include <asm/io.h> 42 #include <linux/scatterlist.h> 43 #include <linux/mm.h> 44 #include <linux/dma-mapping.h> 45 46 #include "usb.h" 47 48 49 const char *usbcore_name = "usbcore"; 50 51 static bool nousb; /* Disable USB when built into kernel image */ 52 53 module_param(nousb, bool, 0444); 54 55 /* 56 * for external read access to <nousb> 57 */ 58 int usb_disabled(void) 59 { 60 return nousb; 61 } 62 EXPORT_SYMBOL_GPL(usb_disabled); 63 64 #ifdef CONFIG_PM 65 static int usb_autosuspend_delay = 2; /* Default delay value, 66 * in seconds */ 67 module_param_named(autosuspend, usb_autosuspend_delay, int, 0644); 68 MODULE_PARM_DESC(autosuspend, "default autosuspend delay"); 69 70 #else 71 #define usb_autosuspend_delay 0 72 #endif 73 74 75 /** 76 * usb_find_alt_setting() - Given a configuration, find the alternate setting 77 * for the given interface. 78 * @config: the configuration to search (not necessarily the current config). 79 * @iface_num: interface number to search in 80 * @alt_num: alternate interface setting number to search for. 81 * 82 * Search the configuration's interface cache for the given alt setting. 83 * 84 * Return: The alternate setting, if found. %NULL otherwise. 85 */ 86 struct usb_host_interface *usb_find_alt_setting( 87 struct usb_host_config *config, 88 unsigned int iface_num, 89 unsigned int alt_num) 90 { 91 struct usb_interface_cache *intf_cache = NULL; 92 int i; 93 94 for (i = 0; i < config->desc.bNumInterfaces; i++) { 95 if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber 96 == iface_num) { 97 intf_cache = config->intf_cache[i]; 98 break; 99 } 100 } 101 if (!intf_cache) 102 return NULL; 103 for (i = 0; i < intf_cache->num_altsetting; i++) 104 if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num) 105 return &intf_cache->altsetting[i]; 106 107 printk(KERN_DEBUG "Did not find alt setting %u for intf %u, " 108 "config %u\n", alt_num, iface_num, 109 config->desc.bConfigurationValue); 110 return NULL; 111 } 112 EXPORT_SYMBOL_GPL(usb_find_alt_setting); 113 114 /** 115 * usb_ifnum_to_if - get the interface object with a given interface number 116 * @dev: the device whose current configuration is considered 117 * @ifnum: the desired interface 118 * 119 * This walks the device descriptor for the currently active configuration 120 * to find the interface object with the particular interface number. 121 * 122 * Note that configuration descriptors are not required to assign interface 123 * numbers sequentially, so that it would be incorrect to assume that 124 * the first interface in that descriptor corresponds to interface zero. 125 * This routine helps device drivers avoid such mistakes. 126 * However, you should make sure that you do the right thing with any 127 * alternate settings available for this interfaces. 128 * 129 * Don't call this function unless you are bound to one of the interfaces 130 * on this device or you have locked the device! 131 * 132 * Return: A pointer to the interface that has @ifnum as interface number, 133 * if found. %NULL otherwise. 134 */ 135 struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev, 136 unsigned ifnum) 137 { 138 struct usb_host_config *config = dev->actconfig; 139 int i; 140 141 if (!config) 142 return NULL; 143 for (i = 0; i < config->desc.bNumInterfaces; i++) 144 if (config->interface[i]->altsetting[0] 145 .desc.bInterfaceNumber == ifnum) 146 return config->interface[i]; 147 148 return NULL; 149 } 150 EXPORT_SYMBOL_GPL(usb_ifnum_to_if); 151 152 /** 153 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number. 154 * @intf: the interface containing the altsetting in question 155 * @altnum: the desired alternate setting number 156 * 157 * This searches the altsetting array of the specified interface for 158 * an entry with the correct bAlternateSetting value. 159 * 160 * Note that altsettings need not be stored sequentially by number, so 161 * it would be incorrect to assume that the first altsetting entry in 162 * the array corresponds to altsetting zero. This routine helps device 163 * drivers avoid such mistakes. 164 * 165 * Don't call this function unless you are bound to the intf interface 166 * or you have locked the device! 167 * 168 * Return: A pointer to the entry of the altsetting array of @intf that 169 * has @altnum as the alternate setting number. %NULL if not found. 170 */ 171 struct usb_host_interface *usb_altnum_to_altsetting( 172 const struct usb_interface *intf, 173 unsigned int altnum) 174 { 175 int i; 176 177 for (i = 0; i < intf->num_altsetting; i++) { 178 if (intf->altsetting[i].desc.bAlternateSetting == altnum) 179 return &intf->altsetting[i]; 180 } 181 return NULL; 182 } 183 EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting); 184 185 struct find_interface_arg { 186 int minor; 187 struct device_driver *drv; 188 }; 189 190 static int __find_interface(struct device *dev, void *data) 191 { 192 struct find_interface_arg *arg = data; 193 struct usb_interface *intf; 194 195 if (!is_usb_interface(dev)) 196 return 0; 197 198 if (dev->driver != arg->drv) 199 return 0; 200 intf = to_usb_interface(dev); 201 return intf->minor == arg->minor; 202 } 203 204 /** 205 * usb_find_interface - find usb_interface pointer for driver and device 206 * @drv: the driver whose current configuration is considered 207 * @minor: the minor number of the desired device 208 * 209 * This walks the bus device list and returns a pointer to the interface 210 * with the matching minor and driver. Note, this only works for devices 211 * that share the USB major number. 212 * 213 * Return: A pointer to the interface with the matching major and @minor. 214 */ 215 struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor) 216 { 217 struct find_interface_arg argb; 218 struct device *dev; 219 220 argb.minor = minor; 221 argb.drv = &drv->drvwrap.driver; 222 223 dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface); 224 225 /* Drop reference count from bus_find_device */ 226 put_device(dev); 227 228 return dev ? to_usb_interface(dev) : NULL; 229 } 230 EXPORT_SYMBOL_GPL(usb_find_interface); 231 232 struct each_dev_arg { 233 void *data; 234 int (*fn)(struct usb_device *, void *); 235 }; 236 237 static int __each_dev(struct device *dev, void *data) 238 { 239 struct each_dev_arg *arg = (struct each_dev_arg *)data; 240 241 /* There are struct usb_interface on the same bus, filter them out */ 242 if (!is_usb_device(dev)) 243 return 0; 244 245 return arg->fn(to_usb_device(dev), arg->data); 246 } 247 248 /** 249 * usb_for_each_dev - iterate over all USB devices in the system 250 * @data: data pointer that will be handed to the callback function 251 * @fn: callback function to be called for each USB device 252 * 253 * Iterate over all USB devices and call @fn for each, passing it @data. If it 254 * returns anything other than 0, we break the iteration prematurely and return 255 * that value. 256 */ 257 int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *)) 258 { 259 struct each_dev_arg arg = {data, fn}; 260 261 return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev); 262 } 263 EXPORT_SYMBOL_GPL(usb_for_each_dev); 264 265 /** 266 * usb_release_dev - free a usb device structure when all users of it are finished. 267 * @dev: device that's been disconnected 268 * 269 * Will be called only by the device core when all users of this usb device are 270 * done. 271 */ 272 static void usb_release_dev(struct device *dev) 273 { 274 struct usb_device *udev; 275 struct usb_hcd *hcd; 276 277 udev = to_usb_device(dev); 278 hcd = bus_to_hcd(udev->bus); 279 280 usb_destroy_configuration(udev); 281 usb_release_bos_descriptor(udev); 282 usb_put_hcd(hcd); 283 kfree(udev->product); 284 kfree(udev->manufacturer); 285 kfree(udev->serial); 286 kfree(udev); 287 } 288 289 static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env) 290 { 291 struct usb_device *usb_dev; 292 293 usb_dev = to_usb_device(dev); 294 295 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum)) 296 return -ENOMEM; 297 298 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum)) 299 return -ENOMEM; 300 301 return 0; 302 } 303 304 #ifdef CONFIG_PM 305 306 /* USB device Power-Management thunks. 307 * There's no need to distinguish here between quiescing a USB device 308 * and powering it down; the generic_suspend() routine takes care of 309 * it by skipping the usb_port_suspend() call for a quiesce. And for 310 * USB interfaces there's no difference at all. 311 */ 312 313 static int usb_dev_prepare(struct device *dev) 314 { 315 return 0; /* Implement eventually? */ 316 } 317 318 static void usb_dev_complete(struct device *dev) 319 { 320 /* Currently used only for rebinding interfaces */ 321 usb_resume_complete(dev); 322 } 323 324 static int usb_dev_suspend(struct device *dev) 325 { 326 return usb_suspend(dev, PMSG_SUSPEND); 327 } 328 329 static int usb_dev_resume(struct device *dev) 330 { 331 return usb_resume(dev, PMSG_RESUME); 332 } 333 334 static int usb_dev_freeze(struct device *dev) 335 { 336 return usb_suspend(dev, PMSG_FREEZE); 337 } 338 339 static int usb_dev_thaw(struct device *dev) 340 { 341 return usb_resume(dev, PMSG_THAW); 342 } 343 344 static int usb_dev_poweroff(struct device *dev) 345 { 346 return usb_suspend(dev, PMSG_HIBERNATE); 347 } 348 349 static int usb_dev_restore(struct device *dev) 350 { 351 return usb_resume(dev, PMSG_RESTORE); 352 } 353 354 static const struct dev_pm_ops usb_device_pm_ops = { 355 .prepare = usb_dev_prepare, 356 .complete = usb_dev_complete, 357 .suspend = usb_dev_suspend, 358 .resume = usb_dev_resume, 359 .freeze = usb_dev_freeze, 360 .thaw = usb_dev_thaw, 361 .poweroff = usb_dev_poweroff, 362 .restore = usb_dev_restore, 363 .runtime_suspend = usb_runtime_suspend, 364 .runtime_resume = usb_runtime_resume, 365 .runtime_idle = usb_runtime_idle, 366 }; 367 368 #endif /* CONFIG_PM */ 369 370 371 static char *usb_devnode(struct device *dev, 372 umode_t *mode, kuid_t *uid, kgid_t *gid) 373 { 374 struct usb_device *usb_dev; 375 376 usb_dev = to_usb_device(dev); 377 return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d", 378 usb_dev->bus->busnum, usb_dev->devnum); 379 } 380 381 struct device_type usb_device_type = { 382 .name = "usb_device", 383 .release = usb_release_dev, 384 .uevent = usb_dev_uevent, 385 .devnode = usb_devnode, 386 #ifdef CONFIG_PM 387 .pm = &usb_device_pm_ops, 388 #endif 389 }; 390 391 392 /* Returns 1 if @usb_bus is WUSB, 0 otherwise */ 393 static unsigned usb_bus_is_wusb(struct usb_bus *bus) 394 { 395 struct usb_hcd *hcd = bus_to_hcd(bus); 396 return hcd->wireless; 397 } 398 399 400 /** 401 * usb_alloc_dev - usb device constructor (usbcore-internal) 402 * @parent: hub to which device is connected; null to allocate a root hub 403 * @bus: bus used to access the device 404 * @port1: one-based index of port; ignored for root hubs 405 * Context: !in_interrupt() 406 * 407 * Only hub drivers (including virtual root hub drivers for host 408 * controllers) should ever call this. 409 * 410 * This call may not be used in a non-sleeping context. 411 * 412 * Return: On success, a pointer to the allocated usb device. %NULL on 413 * failure. 414 */ 415 struct usb_device *usb_alloc_dev(struct usb_device *parent, 416 struct usb_bus *bus, unsigned port1) 417 { 418 struct usb_device *dev; 419 struct usb_hcd *usb_hcd = bus_to_hcd(bus); 420 unsigned root_hub = 0; 421 unsigned raw_port = port1; 422 423 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 424 if (!dev) 425 return NULL; 426 427 if (!usb_get_hcd(usb_hcd)) { 428 kfree(dev); 429 return NULL; 430 } 431 /* Root hubs aren't true devices, so don't allocate HCD resources */ 432 if (usb_hcd->driver->alloc_dev && parent && 433 !usb_hcd->driver->alloc_dev(usb_hcd, dev)) { 434 usb_put_hcd(bus_to_hcd(bus)); 435 kfree(dev); 436 return NULL; 437 } 438 439 device_initialize(&dev->dev); 440 dev->dev.bus = &usb_bus_type; 441 dev->dev.type = &usb_device_type; 442 dev->dev.groups = usb_device_groups; 443 /* 444 * Fake a dma_mask/offset for the USB device: 445 * We cannot really use the dma-mapping API (dma_alloc_* and 446 * dma_map_*) for USB devices but instead need to use 447 * usb_alloc_coherent and pass data in 'urb's, but some subsystems 448 * manually look into the mask/offset pair to determine whether 449 * they need bounce buffers. 450 * Note: calling dma_set_mask() on a USB device would set the 451 * mask for the entire HCD, so don't do that. 452 */ 453 dev->dev.dma_mask = bus->controller->dma_mask; 454 dev->dev.dma_pfn_offset = bus->controller->dma_pfn_offset; 455 set_dev_node(&dev->dev, dev_to_node(bus->controller)); 456 dev->state = USB_STATE_ATTACHED; 457 dev->lpm_disable_count = 1; 458 atomic_set(&dev->urbnum, 0); 459 460 INIT_LIST_HEAD(&dev->ep0.urb_list); 461 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE; 462 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT; 463 /* ep0 maxpacket comes later, from device descriptor */ 464 usb_enable_endpoint(dev, &dev->ep0, false); 465 dev->can_submit = 1; 466 467 /* Save readable and stable topology id, distinguishing devices 468 * by location for diagnostics, tools, driver model, etc. The 469 * string is a path along hub ports, from the root. Each device's 470 * dev->devpath will be stable until USB is re-cabled, and hubs 471 * are often labeled with these port numbers. The name isn't 472 * as stable: bus->busnum changes easily from modprobe order, 473 * cardbus or pci hotplugging, and so on. 474 */ 475 if (unlikely(!parent)) { 476 dev->devpath[0] = '0'; 477 dev->route = 0; 478 479 dev->dev.parent = bus->controller; 480 dev_set_name(&dev->dev, "usb%d", bus->busnum); 481 root_hub = 1; 482 } else { 483 /* match any labeling on the hubs; it's one-based */ 484 if (parent->devpath[0] == '0') { 485 snprintf(dev->devpath, sizeof dev->devpath, 486 "%d", port1); 487 /* Root ports are not counted in route string */ 488 dev->route = 0; 489 } else { 490 snprintf(dev->devpath, sizeof dev->devpath, 491 "%s.%d", parent->devpath, port1); 492 /* Route string assumes hubs have less than 16 ports */ 493 if (port1 < 15) 494 dev->route = parent->route + 495 (port1 << ((parent->level - 1)*4)); 496 else 497 dev->route = parent->route + 498 (15 << ((parent->level - 1)*4)); 499 } 500 501 dev->dev.parent = &parent->dev; 502 dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath); 503 504 if (!parent->parent) { 505 /* device under root hub's port */ 506 raw_port = usb_hcd_find_raw_port_number(usb_hcd, 507 port1); 508 } 509 dev->dev.of_node = usb_of_get_child_node(parent->dev.of_node, 510 raw_port); 511 512 /* hub driver sets up TT records */ 513 } 514 515 dev->portnum = port1; 516 dev->bus = bus; 517 dev->parent = parent; 518 INIT_LIST_HEAD(&dev->filelist); 519 520 #ifdef CONFIG_PM 521 pm_runtime_set_autosuspend_delay(&dev->dev, 522 usb_autosuspend_delay * 1000); 523 dev->connect_time = jiffies; 524 dev->active_duration = -jiffies; 525 #endif 526 if (root_hub) /* Root hub always ok [and always wired] */ 527 dev->authorized = 1; 528 else { 529 dev->authorized = !!HCD_DEV_AUTHORIZED(usb_hcd); 530 dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0; 531 } 532 return dev; 533 } 534 EXPORT_SYMBOL_GPL(usb_alloc_dev); 535 536 /** 537 * usb_get_dev - increments the reference count of the usb device structure 538 * @dev: the device being referenced 539 * 540 * Each live reference to a device should be refcounted. 541 * 542 * Drivers for USB interfaces should normally record such references in 543 * their probe() methods, when they bind to an interface, and release 544 * them by calling usb_put_dev(), in their disconnect() methods. 545 * 546 * Return: A pointer to the device with the incremented reference counter. 547 */ 548 struct usb_device *usb_get_dev(struct usb_device *dev) 549 { 550 if (dev) 551 get_device(&dev->dev); 552 return dev; 553 } 554 EXPORT_SYMBOL_GPL(usb_get_dev); 555 556 /** 557 * usb_put_dev - release a use of the usb device structure 558 * @dev: device that's been disconnected 559 * 560 * Must be called when a user of a device is finished with it. When the last 561 * user of the device calls this function, the memory of the device is freed. 562 */ 563 void usb_put_dev(struct usb_device *dev) 564 { 565 if (dev) 566 put_device(&dev->dev); 567 } 568 EXPORT_SYMBOL_GPL(usb_put_dev); 569 570 /** 571 * usb_get_intf - increments the reference count of the usb interface structure 572 * @intf: the interface being referenced 573 * 574 * Each live reference to a interface must be refcounted. 575 * 576 * Drivers for USB interfaces should normally record such references in 577 * their probe() methods, when they bind to an interface, and release 578 * them by calling usb_put_intf(), in their disconnect() methods. 579 * 580 * Return: A pointer to the interface with the incremented reference counter. 581 */ 582 struct usb_interface *usb_get_intf(struct usb_interface *intf) 583 { 584 if (intf) 585 get_device(&intf->dev); 586 return intf; 587 } 588 EXPORT_SYMBOL_GPL(usb_get_intf); 589 590 /** 591 * usb_put_intf - release a use of the usb interface structure 592 * @intf: interface that's been decremented 593 * 594 * Must be called when a user of an interface is finished with it. When the 595 * last user of the interface calls this function, the memory of the interface 596 * is freed. 597 */ 598 void usb_put_intf(struct usb_interface *intf) 599 { 600 if (intf) 601 put_device(&intf->dev); 602 } 603 EXPORT_SYMBOL_GPL(usb_put_intf); 604 605 /* USB device locking 606 * 607 * USB devices and interfaces are locked using the semaphore in their 608 * embedded struct device. The hub driver guarantees that whenever a 609 * device is connected or disconnected, drivers are called with the 610 * USB device locked as well as their particular interface. 611 * 612 * Complications arise when several devices are to be locked at the same 613 * time. Only hub-aware drivers that are part of usbcore ever have to 614 * do this; nobody else needs to worry about it. The rule for locking 615 * is simple: 616 * 617 * When locking both a device and its parent, always lock the 618 * the parent first. 619 */ 620 621 /** 622 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure 623 * @udev: device that's being locked 624 * @iface: interface bound to the driver making the request (optional) 625 * 626 * Attempts to acquire the device lock, but fails if the device is 627 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface 628 * is neither BINDING nor BOUND. Rather than sleeping to wait for the 629 * lock, the routine polls repeatedly. This is to prevent deadlock with 630 * disconnect; in some drivers (such as usb-storage) the disconnect() 631 * or suspend() method will block waiting for a device reset to complete. 632 * 633 * Return: A negative error code for failure, otherwise 0. 634 */ 635 int usb_lock_device_for_reset(struct usb_device *udev, 636 const struct usb_interface *iface) 637 { 638 unsigned long jiffies_expire = jiffies + HZ; 639 640 if (udev->state == USB_STATE_NOTATTACHED) 641 return -ENODEV; 642 if (udev->state == USB_STATE_SUSPENDED) 643 return -EHOSTUNREACH; 644 if (iface && (iface->condition == USB_INTERFACE_UNBINDING || 645 iface->condition == USB_INTERFACE_UNBOUND)) 646 return -EINTR; 647 648 while (!usb_trylock_device(udev)) { 649 650 /* If we can't acquire the lock after waiting one second, 651 * we're probably deadlocked */ 652 if (time_after(jiffies, jiffies_expire)) 653 return -EBUSY; 654 655 msleep(15); 656 if (udev->state == USB_STATE_NOTATTACHED) 657 return -ENODEV; 658 if (udev->state == USB_STATE_SUSPENDED) 659 return -EHOSTUNREACH; 660 if (iface && (iface->condition == USB_INTERFACE_UNBINDING || 661 iface->condition == USB_INTERFACE_UNBOUND)) 662 return -EINTR; 663 } 664 return 0; 665 } 666 EXPORT_SYMBOL_GPL(usb_lock_device_for_reset); 667 668 /** 669 * usb_get_current_frame_number - return current bus frame number 670 * @dev: the device whose bus is being queried 671 * 672 * Return: The current frame number for the USB host controller used 673 * with the given USB device. This can be used when scheduling 674 * isochronous requests. 675 * 676 * Note: Different kinds of host controller have different "scheduling 677 * horizons". While one type might support scheduling only 32 frames 678 * into the future, others could support scheduling up to 1024 frames 679 * into the future. 680 * 681 */ 682 int usb_get_current_frame_number(struct usb_device *dev) 683 { 684 return usb_hcd_get_frame_number(dev); 685 } 686 EXPORT_SYMBOL_GPL(usb_get_current_frame_number); 687 688 /*-------------------------------------------------------------------*/ 689 /* 690 * __usb_get_extra_descriptor() finds a descriptor of specific type in the 691 * extra field of the interface and endpoint descriptor structs. 692 */ 693 694 int __usb_get_extra_descriptor(char *buffer, unsigned size, 695 unsigned char type, void **ptr) 696 { 697 struct usb_descriptor_header *header; 698 699 while (size >= sizeof(struct usb_descriptor_header)) { 700 header = (struct usb_descriptor_header *)buffer; 701 702 if (header->bLength < 2) { 703 printk(KERN_ERR 704 "%s: bogus descriptor, type %d length %d\n", 705 usbcore_name, 706 header->bDescriptorType, 707 header->bLength); 708 return -1; 709 } 710 711 if (header->bDescriptorType == type) { 712 *ptr = header; 713 return 0; 714 } 715 716 buffer += header->bLength; 717 size -= header->bLength; 718 } 719 return -1; 720 } 721 EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor); 722 723 /** 724 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP 725 * @dev: device the buffer will be used with 726 * @size: requested buffer size 727 * @mem_flags: affect whether allocation may block 728 * @dma: used to return DMA address of buffer 729 * 730 * Return: Either null (indicating no buffer could be allocated), or the 731 * cpu-space pointer to a buffer that may be used to perform DMA to the 732 * specified device. Such cpu-space buffers are returned along with the DMA 733 * address (through the pointer provided). 734 * 735 * Note: 736 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags 737 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU 738 * hardware during URB completion/resubmit. The implementation varies between 739 * platforms, depending on details of how DMA will work to this device. 740 * Using these buffers also eliminates cacheline sharing problems on 741 * architectures where CPU caches are not DMA-coherent. On systems without 742 * bus-snooping caches, these buffers are uncached. 743 * 744 * When the buffer is no longer used, free it with usb_free_coherent(). 745 */ 746 void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags, 747 dma_addr_t *dma) 748 { 749 if (!dev || !dev->bus) 750 return NULL; 751 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma); 752 } 753 EXPORT_SYMBOL_GPL(usb_alloc_coherent); 754 755 /** 756 * usb_free_coherent - free memory allocated with usb_alloc_coherent() 757 * @dev: device the buffer was used with 758 * @size: requested buffer size 759 * @addr: CPU address of buffer 760 * @dma: DMA address of buffer 761 * 762 * This reclaims an I/O buffer, letting it be reused. The memory must have 763 * been allocated using usb_alloc_coherent(), and the parameters must match 764 * those provided in that allocation request. 765 */ 766 void usb_free_coherent(struct usb_device *dev, size_t size, void *addr, 767 dma_addr_t dma) 768 { 769 if (!dev || !dev->bus) 770 return; 771 if (!addr) 772 return; 773 hcd_buffer_free(dev->bus, size, addr, dma); 774 } 775 EXPORT_SYMBOL_GPL(usb_free_coherent); 776 777 /** 778 * usb_buffer_map - create DMA mapping(s) for an urb 779 * @urb: urb whose transfer_buffer/setup_packet will be mapped 780 * 781 * URB_NO_TRANSFER_DMA_MAP is added to urb->transfer_flags if the operation 782 * succeeds. If the device is connected to this system through a non-DMA 783 * controller, this operation always succeeds. 784 * 785 * This call would normally be used for an urb which is reused, perhaps 786 * as the target of a large periodic transfer, with usb_buffer_dmasync() 787 * calls to synchronize memory and dma state. 788 * 789 * Reverse the effect of this call with usb_buffer_unmap(). 790 * 791 * Return: Either %NULL (indicating no buffer could be mapped), or @urb. 792 * 793 */ 794 #if 0 795 struct urb *usb_buffer_map(struct urb *urb) 796 { 797 struct usb_bus *bus; 798 struct device *controller; 799 800 if (!urb 801 || !urb->dev 802 || !(bus = urb->dev->bus) 803 || !(controller = bus->controller)) 804 return NULL; 805 806 if (controller->dma_mask) { 807 urb->transfer_dma = dma_map_single(controller, 808 urb->transfer_buffer, urb->transfer_buffer_length, 809 usb_pipein(urb->pipe) 810 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 811 /* FIXME generic api broken like pci, can't report errors */ 812 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */ 813 } else 814 urb->transfer_dma = ~0; 815 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 816 return urb; 817 } 818 EXPORT_SYMBOL_GPL(usb_buffer_map); 819 #endif /* 0 */ 820 821 /* XXX DISABLED, no users currently. If you wish to re-enable this 822 * XXX please determine whether the sync is to transfer ownership of 823 * XXX the buffer from device to cpu or vice verse, and thusly use the 824 * XXX appropriate _for_{cpu,device}() method. -DaveM 825 */ 826 #if 0 827 828 /** 829 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s) 830 * @urb: urb whose transfer_buffer/setup_packet will be synchronized 831 */ 832 void usb_buffer_dmasync(struct urb *urb) 833 { 834 struct usb_bus *bus; 835 struct device *controller; 836 837 if (!urb 838 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) 839 || !urb->dev 840 || !(bus = urb->dev->bus) 841 || !(controller = bus->controller)) 842 return; 843 844 if (controller->dma_mask) { 845 dma_sync_single_for_cpu(controller, 846 urb->transfer_dma, urb->transfer_buffer_length, 847 usb_pipein(urb->pipe) 848 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 849 if (usb_pipecontrol(urb->pipe)) 850 dma_sync_single_for_cpu(controller, 851 urb->setup_dma, 852 sizeof(struct usb_ctrlrequest), 853 DMA_TO_DEVICE); 854 } 855 } 856 EXPORT_SYMBOL_GPL(usb_buffer_dmasync); 857 #endif 858 859 /** 860 * usb_buffer_unmap - free DMA mapping(s) for an urb 861 * @urb: urb whose transfer_buffer will be unmapped 862 * 863 * Reverses the effect of usb_buffer_map(). 864 */ 865 #if 0 866 void usb_buffer_unmap(struct urb *urb) 867 { 868 struct usb_bus *bus; 869 struct device *controller; 870 871 if (!urb 872 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) 873 || !urb->dev 874 || !(bus = urb->dev->bus) 875 || !(controller = bus->controller)) 876 return; 877 878 if (controller->dma_mask) { 879 dma_unmap_single(controller, 880 urb->transfer_dma, urb->transfer_buffer_length, 881 usb_pipein(urb->pipe) 882 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 883 } 884 urb->transfer_flags &= ~URB_NO_TRANSFER_DMA_MAP; 885 } 886 EXPORT_SYMBOL_GPL(usb_buffer_unmap); 887 #endif /* 0 */ 888 889 #if 0 890 /** 891 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint 892 * @dev: device to which the scatterlist will be mapped 893 * @is_in: mapping transfer direction 894 * @sg: the scatterlist to map 895 * @nents: the number of entries in the scatterlist 896 * 897 * Return: Either < 0 (indicating no buffers could be mapped), or the 898 * number of DMA mapping array entries in the scatterlist. 899 * 900 * Note: 901 * The caller is responsible for placing the resulting DMA addresses from 902 * the scatterlist into URB transfer buffer pointers, and for setting the 903 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs. 904 * 905 * Top I/O rates come from queuing URBs, instead of waiting for each one 906 * to complete before starting the next I/O. This is particularly easy 907 * to do with scatterlists. Just allocate and submit one URB for each DMA 908 * mapping entry returned, stopping on the first error or when all succeed. 909 * Better yet, use the usb_sg_*() calls, which do that (and more) for you. 910 * 911 * This call would normally be used when translating scatterlist requests, 912 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it 913 * may be able to coalesce mappings for improved I/O efficiency. 914 * 915 * Reverse the effect of this call with usb_buffer_unmap_sg(). 916 */ 917 int usb_buffer_map_sg(const struct usb_device *dev, int is_in, 918 struct scatterlist *sg, int nents) 919 { 920 struct usb_bus *bus; 921 struct device *controller; 922 923 if (!dev 924 || !(bus = dev->bus) 925 || !(controller = bus->controller) 926 || !controller->dma_mask) 927 return -EINVAL; 928 929 /* FIXME generic api broken like pci, can't report errors */ 930 return dma_map_sg(controller, sg, nents, 931 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE) ? : -ENOMEM; 932 } 933 EXPORT_SYMBOL_GPL(usb_buffer_map_sg); 934 #endif 935 936 /* XXX DISABLED, no users currently. If you wish to re-enable this 937 * XXX please determine whether the sync is to transfer ownership of 938 * XXX the buffer from device to cpu or vice verse, and thusly use the 939 * XXX appropriate _for_{cpu,device}() method. -DaveM 940 */ 941 #if 0 942 943 /** 944 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s) 945 * @dev: device to which the scatterlist will be mapped 946 * @is_in: mapping transfer direction 947 * @sg: the scatterlist to synchronize 948 * @n_hw_ents: the positive return value from usb_buffer_map_sg 949 * 950 * Use this when you are re-using a scatterlist's data buffers for 951 * another USB request. 952 */ 953 void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in, 954 struct scatterlist *sg, int n_hw_ents) 955 { 956 struct usb_bus *bus; 957 struct device *controller; 958 959 if (!dev 960 || !(bus = dev->bus) 961 || !(controller = bus->controller) 962 || !controller->dma_mask) 963 return; 964 965 dma_sync_sg_for_cpu(controller, sg, n_hw_ents, 966 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 967 } 968 EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg); 969 #endif 970 971 #if 0 972 /** 973 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist 974 * @dev: device to which the scatterlist will be mapped 975 * @is_in: mapping transfer direction 976 * @sg: the scatterlist to unmap 977 * @n_hw_ents: the positive return value from usb_buffer_map_sg 978 * 979 * Reverses the effect of usb_buffer_map_sg(). 980 */ 981 void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in, 982 struct scatterlist *sg, int n_hw_ents) 983 { 984 struct usb_bus *bus; 985 struct device *controller; 986 987 if (!dev 988 || !(bus = dev->bus) 989 || !(controller = bus->controller) 990 || !controller->dma_mask) 991 return; 992 993 dma_unmap_sg(controller, sg, n_hw_ents, 994 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 995 } 996 EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg); 997 #endif 998 999 /* 1000 * Notifications of device and interface registration 1001 */ 1002 static int usb_bus_notify(struct notifier_block *nb, unsigned long action, 1003 void *data) 1004 { 1005 struct device *dev = data; 1006 1007 switch (action) { 1008 case BUS_NOTIFY_ADD_DEVICE: 1009 if (dev->type == &usb_device_type) 1010 (void) usb_create_sysfs_dev_files(to_usb_device(dev)); 1011 else if (dev->type == &usb_if_device_type) 1012 usb_create_sysfs_intf_files(to_usb_interface(dev)); 1013 break; 1014 1015 case BUS_NOTIFY_DEL_DEVICE: 1016 if (dev->type == &usb_device_type) 1017 usb_remove_sysfs_dev_files(to_usb_device(dev)); 1018 else if (dev->type == &usb_if_device_type) 1019 usb_remove_sysfs_intf_files(to_usb_interface(dev)); 1020 break; 1021 } 1022 return 0; 1023 } 1024 1025 static struct notifier_block usb_bus_nb = { 1026 .notifier_call = usb_bus_notify, 1027 }; 1028 1029 struct dentry *usb_debug_root; 1030 EXPORT_SYMBOL_GPL(usb_debug_root); 1031 1032 static struct dentry *usb_debug_devices; 1033 1034 static int usb_debugfs_init(void) 1035 { 1036 usb_debug_root = debugfs_create_dir("usb", NULL); 1037 if (!usb_debug_root) 1038 return -ENOENT; 1039 1040 usb_debug_devices = debugfs_create_file("devices", 0444, 1041 usb_debug_root, NULL, 1042 &usbfs_devices_fops); 1043 if (!usb_debug_devices) { 1044 debugfs_remove(usb_debug_root); 1045 usb_debug_root = NULL; 1046 return -ENOENT; 1047 } 1048 1049 return 0; 1050 } 1051 1052 static void usb_debugfs_cleanup(void) 1053 { 1054 debugfs_remove(usb_debug_devices); 1055 debugfs_remove(usb_debug_root); 1056 } 1057 1058 /* 1059 * Init 1060 */ 1061 static int __init usb_init(void) 1062 { 1063 int retval; 1064 if (usb_disabled()) { 1065 pr_info("%s: USB support disabled\n", usbcore_name); 1066 return 0; 1067 } 1068 usb_init_pool_max(); 1069 1070 retval = usb_debugfs_init(); 1071 if (retval) 1072 goto out; 1073 1074 usb_acpi_register(); 1075 retval = bus_register(&usb_bus_type); 1076 if (retval) 1077 goto bus_register_failed; 1078 retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb); 1079 if (retval) 1080 goto bus_notifier_failed; 1081 retval = usb_major_init(); 1082 if (retval) 1083 goto major_init_failed; 1084 retval = usb_register(&usbfs_driver); 1085 if (retval) 1086 goto driver_register_failed; 1087 retval = usb_devio_init(); 1088 if (retval) 1089 goto usb_devio_init_failed; 1090 retval = usb_hub_init(); 1091 if (retval) 1092 goto hub_init_failed; 1093 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE); 1094 if (!retval) 1095 goto out; 1096 1097 usb_hub_cleanup(); 1098 hub_init_failed: 1099 usb_devio_cleanup(); 1100 usb_devio_init_failed: 1101 usb_deregister(&usbfs_driver); 1102 driver_register_failed: 1103 usb_major_cleanup(); 1104 major_init_failed: 1105 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb); 1106 bus_notifier_failed: 1107 bus_unregister(&usb_bus_type); 1108 bus_register_failed: 1109 usb_acpi_unregister(); 1110 usb_debugfs_cleanup(); 1111 out: 1112 return retval; 1113 } 1114 1115 /* 1116 * Cleanup 1117 */ 1118 static void __exit usb_exit(void) 1119 { 1120 /* This will matter if shutdown/reboot does exitcalls. */ 1121 if (usb_disabled()) 1122 return; 1123 1124 usb_deregister_device_driver(&usb_generic_driver); 1125 usb_major_cleanup(); 1126 usb_deregister(&usbfs_driver); 1127 usb_devio_cleanup(); 1128 usb_hub_cleanup(); 1129 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb); 1130 bus_unregister(&usb_bus_type); 1131 usb_acpi_unregister(); 1132 usb_debugfs_cleanup(); 1133 idr_destroy(&usb_bus_idr); 1134 } 1135 1136 subsys_initcall(usb_init); 1137 module_exit(usb_exit); 1138 MODULE_LICENSE("GPL"); 1139