usb.c revision 4a9bee8256a2dec26290a3bfff86ab86b8992547
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/mutex.h> 36#include <linux/workqueue.h> 37 38#include <asm/io.h> 39#include <linux/scatterlist.h> 40#include <linux/mm.h> 41#include <linux/dma-mapping.h> 42 43#include "hcd.h" 44#include "usb.h" 45 46 47const char *usbcore_name = "usbcore"; 48 49static int nousb; /* Disable USB when built into kernel image */ 50 51/* Workqueue for autosuspend and for remote wakeup of root hubs */ 52struct workqueue_struct *ksuspend_usb_wq; 53 54#ifdef CONFIG_USB_SUSPEND 55static int usb_autosuspend_delay = 2; /* Default delay value, 56 * in seconds */ 57module_param_named(autosuspend, usb_autosuspend_delay, int, 0644); 58MODULE_PARM_DESC(autosuspend, "default autosuspend delay"); 59 60#else 61#define usb_autosuspend_delay 0 62#endif 63 64 65/** 66 * usb_ifnum_to_if - get the interface object with a given interface number 67 * @dev: the device whose current configuration is considered 68 * @ifnum: the desired interface 69 * 70 * This walks the device descriptor for the currently active configuration 71 * and returns a pointer to the interface with that particular interface 72 * number, or null. 73 * 74 * Note that configuration descriptors are not required to assign interface 75 * numbers sequentially, so that it would be incorrect to assume that 76 * the first interface in that descriptor corresponds to interface zero. 77 * This routine helps device drivers avoid such mistakes. 78 * However, you should make sure that you do the right thing with any 79 * alternate settings available for this interfaces. 80 * 81 * Don't call this function unless you are bound to one of the interfaces 82 * on this device or you have locked the device! 83 */ 84struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev, 85 unsigned ifnum) 86{ 87 struct usb_host_config *config = dev->actconfig; 88 int i; 89 90 if (!config) 91 return NULL; 92 for (i = 0; i < config->desc.bNumInterfaces; i++) 93 if (config->interface[i]->altsetting[0] 94 .desc.bInterfaceNumber == ifnum) 95 return config->interface[i]; 96 97 return NULL; 98} 99 100/** 101 * usb_altnum_to_altsetting - get the altsetting structure with a given 102 * alternate setting number. 103 * @intf: the interface containing the altsetting in question 104 * @altnum: the desired alternate setting number 105 * 106 * This searches the altsetting array of the specified interface for 107 * an entry with the correct bAlternateSetting value and returns a pointer 108 * to that entry, or null. 109 * 110 * Note that altsettings need not be stored sequentially by number, so 111 * it would be incorrect to assume that the first altsetting entry in 112 * the array corresponds to altsetting zero. This routine helps device 113 * drivers avoid such mistakes. 114 * 115 * Don't call this function unless you are bound to the intf interface 116 * or you have locked the device! 117 */ 118struct usb_host_interface *usb_altnum_to_altsetting(const struct usb_interface *intf, 119 unsigned int altnum) 120{ 121 int i; 122 123 for (i = 0; i < intf->num_altsetting; i++) { 124 if (intf->altsetting[i].desc.bAlternateSetting == altnum) 125 return &intf->altsetting[i]; 126 } 127 return NULL; 128} 129 130struct find_interface_arg { 131 int minor; 132 struct usb_interface *interface; 133}; 134 135static int __find_interface(struct device * dev, void * data) 136{ 137 struct find_interface_arg *arg = data; 138 struct usb_interface *intf; 139 140 /* can't look at usb devices, only interfaces */ 141 if (is_usb_device(dev)) 142 return 0; 143 144 intf = to_usb_interface(dev); 145 if (intf->minor != -1 && intf->minor == arg->minor) { 146 arg->interface = intf; 147 return 1; 148 } 149 return 0; 150} 151 152/** 153 * usb_find_interface - find usb_interface pointer for driver and device 154 * @drv: the driver whose current configuration is considered 155 * @minor: the minor number of the desired device 156 * 157 * This walks the driver device list and returns a pointer to the interface 158 * with the matching minor. Note, this only works for devices that share the 159 * USB major number. 160 */ 161struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor) 162{ 163 struct find_interface_arg argb; 164 int retval; 165 166 argb.minor = minor; 167 argb.interface = NULL; 168 /* eat the error, it will be in argb.interface */ 169 retval = driver_for_each_device(&drv->drvwrap.driver, NULL, &argb, 170 __find_interface); 171 return argb.interface; 172} 173 174/** 175 * usb_release_dev - free a usb device structure when all users of it are finished. 176 * @dev: device that's been disconnected 177 * 178 * Will be called only by the device core when all users of this usb device are 179 * done. 180 */ 181static void usb_release_dev(struct device *dev) 182{ 183 struct usb_device *udev; 184 185 udev = to_usb_device(dev); 186 187 usb_destroy_configuration(udev); 188 usb_put_hcd(bus_to_hcd(udev->bus)); 189 kfree(udev->product); 190 kfree(udev->manufacturer); 191 kfree(udev->serial); 192 kfree(udev); 193} 194 195#ifdef CONFIG_HOTPLUG 196static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env) 197{ 198 struct usb_device *usb_dev; 199 200 usb_dev = to_usb_device(dev); 201 202 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum)) 203 return -ENOMEM; 204 205 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum)) 206 return -ENOMEM; 207 208 return 0; 209} 210 211#else 212 213static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env) 214{ 215 return -ENODEV; 216} 217#endif /* CONFIG_HOTPLUG */ 218 219struct device_type usb_device_type = { 220 .name = "usb_device", 221 .release = usb_release_dev, 222 .uevent = usb_dev_uevent, 223}; 224 225#ifdef CONFIG_PM 226 227static int ksuspend_usb_init(void) 228{ 229 /* This workqueue is supposed to be both freezable and 230 * singlethreaded. Its job doesn't justify running on more 231 * than one CPU. 232 */ 233 ksuspend_usb_wq = create_freezeable_workqueue("ksuspend_usbd"); 234 if (!ksuspend_usb_wq) 235 return -ENOMEM; 236 return 0; 237} 238 239static void ksuspend_usb_cleanup(void) 240{ 241 destroy_workqueue(ksuspend_usb_wq); 242} 243 244#else 245 246#define ksuspend_usb_init() 0 247#define ksuspend_usb_cleanup() do {} while (0) 248 249#endif /* CONFIG_PM */ 250 251 252/* Returns 1 if @usb_bus is WUSB, 0 otherwise */ 253static unsigned usb_bus_is_wusb(struct usb_bus *bus) 254{ 255 struct usb_hcd *hcd = container_of(bus, struct usb_hcd, self); 256 return hcd->wireless; 257} 258 259 260/** 261 * usb_alloc_dev - usb device constructor (usbcore-internal) 262 * @parent: hub to which device is connected; null to allocate a root hub 263 * @bus: bus used to access the device 264 * @port1: one-based index of port; ignored for root hubs 265 * Context: !in_interrupt() 266 * 267 * Only hub drivers (including virtual root hub drivers for host 268 * controllers) should ever call this. 269 * 270 * This call may not be used in a non-sleeping context. 271 */ 272struct usb_device * 273usb_alloc_dev(struct usb_device *parent, struct usb_bus *bus, unsigned port1) 274{ 275 struct usb_device *dev; 276 struct usb_hcd *usb_hcd = container_of(bus, struct usb_hcd, self); 277 unsigned root_hub = 0; 278 279 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 280 if (!dev) 281 return NULL; 282 283 if (!usb_get_hcd(bus_to_hcd(bus))) { 284 kfree(dev); 285 return NULL; 286 } 287 288 device_initialize(&dev->dev); 289 dev->dev.bus = &usb_bus_type; 290 dev->dev.type = &usb_device_type; 291 dev->dev.dma_mask = bus->controller->dma_mask; 292 set_dev_node(&dev->dev, dev_to_node(bus->controller)); 293 dev->state = USB_STATE_ATTACHED; 294 atomic_set(&dev->urbnum, 0); 295 296 INIT_LIST_HEAD(&dev->ep0.urb_list); 297 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE; 298 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT; 299 /* ep0 maxpacket comes later, from device descriptor */ 300 usb_enable_endpoint(dev, &dev->ep0); 301 dev->can_submit = 1; 302 303 /* Save readable and stable topology id, distinguishing devices 304 * by location for diagnostics, tools, driver model, etc. The 305 * string is a path along hub ports, from the root. Each device's 306 * dev->devpath will be stable until USB is re-cabled, and hubs 307 * are often labeled with these port numbers. The bus_id isn't 308 * as stable: bus->busnum changes easily from modprobe order, 309 * cardbus or pci hotplugging, and so on. 310 */ 311 if (unlikely(!parent)) { 312 dev->devpath[0] = '0'; 313 314 dev->dev.parent = bus->controller; 315 sprintf(&dev->dev.bus_id[0], "usb%d", bus->busnum); 316 root_hub = 1; 317 } else { 318 /* match any labeling on the hubs; it's one-based */ 319 if (parent->devpath[0] == '0') 320 snprintf(dev->devpath, sizeof dev->devpath, 321 "%d", port1); 322 else 323 snprintf(dev->devpath, sizeof dev->devpath, 324 "%s.%d", parent->devpath, port1); 325 326 dev->dev.parent = &parent->dev; 327 sprintf(&dev->dev.bus_id[0], "%d-%s", 328 bus->busnum, dev->devpath); 329 330 /* hub driver sets up TT records */ 331 } 332 333 dev->portnum = port1; 334 dev->bus = bus; 335 dev->parent = parent; 336 INIT_LIST_HEAD(&dev->filelist); 337 338#ifdef CONFIG_PM 339 mutex_init(&dev->pm_mutex); 340 INIT_DELAYED_WORK(&dev->autosuspend, usb_autosuspend_work); 341 dev->autosuspend_delay = usb_autosuspend_delay * HZ; 342#endif 343 if (root_hub) /* Root hub always ok [and always wired] */ 344 dev->authorized = 1; 345 else { 346 dev->authorized = usb_hcd->authorized_default; 347 dev->wusb = usb_bus_is_wusb(bus)? 1 : 0; 348 } 349 return dev; 350} 351 352/** 353 * usb_get_dev - increments the reference count of the usb device structure 354 * @dev: the device being referenced 355 * 356 * Each live reference to a device should be refcounted. 357 * 358 * Drivers for USB interfaces should normally record such references in 359 * their probe() methods, when they bind to an interface, and release 360 * them by calling usb_put_dev(), in their disconnect() methods. 361 * 362 * A pointer to the device with the incremented reference counter is returned. 363 */ 364struct usb_device *usb_get_dev(struct usb_device *dev) 365{ 366 if (dev) 367 get_device(&dev->dev); 368 return dev; 369} 370 371/** 372 * usb_put_dev - release a use of the usb device structure 373 * @dev: device that's been disconnected 374 * 375 * Must be called when a user of a device is finished with it. When the last 376 * user of the device calls this function, the memory of the device is freed. 377 */ 378void usb_put_dev(struct usb_device *dev) 379{ 380 if (dev) 381 put_device(&dev->dev); 382} 383 384/** 385 * usb_get_intf - increments the reference count of the usb interface structure 386 * @intf: the interface being referenced 387 * 388 * Each live reference to a interface must be refcounted. 389 * 390 * Drivers for USB interfaces should normally record such references in 391 * their probe() methods, when they bind to an interface, and release 392 * them by calling usb_put_intf(), in their disconnect() methods. 393 * 394 * A pointer to the interface with the incremented reference counter is 395 * returned. 396 */ 397struct usb_interface *usb_get_intf(struct usb_interface *intf) 398{ 399 if (intf) 400 get_device(&intf->dev); 401 return intf; 402} 403 404/** 405 * usb_put_intf - release a use of the usb interface structure 406 * @intf: interface that's been decremented 407 * 408 * Must be called when a user of an interface is finished with it. When the 409 * last user of the interface calls this function, the memory of the interface 410 * is freed. 411 */ 412void usb_put_intf(struct usb_interface *intf) 413{ 414 if (intf) 415 put_device(&intf->dev); 416} 417 418 419/* USB device locking 420 * 421 * USB devices and interfaces are locked using the semaphore in their 422 * embedded struct device. The hub driver guarantees that whenever a 423 * device is connected or disconnected, drivers are called with the 424 * USB device locked as well as their particular interface. 425 * 426 * Complications arise when several devices are to be locked at the same 427 * time. Only hub-aware drivers that are part of usbcore ever have to 428 * do this; nobody else needs to worry about it. The rule for locking 429 * is simple: 430 * 431 * When locking both a device and its parent, always lock the 432 * the parent first. 433 */ 434 435/** 436 * usb_lock_device_for_reset - cautiously acquire the lock for a 437 * usb device structure 438 * @udev: device that's being locked 439 * @iface: interface bound to the driver making the request (optional) 440 * 441 * Attempts to acquire the device lock, but fails if the device is 442 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface 443 * is neither BINDING nor BOUND. Rather than sleeping to wait for the 444 * lock, the routine polls repeatedly. This is to prevent deadlock with 445 * disconnect; in some drivers (such as usb-storage) the disconnect() 446 * or suspend() method will block waiting for a device reset to complete. 447 * 448 * Returns a negative error code for failure, otherwise 1 or 0 to indicate 449 * that the device will or will not have to be unlocked. (0 can be 450 * returned when an interface is given and is BINDING, because in that 451 * case the driver already owns the device lock.) 452 */ 453int usb_lock_device_for_reset(struct usb_device *udev, 454 const struct usb_interface *iface) 455{ 456 unsigned long jiffies_expire = jiffies + HZ; 457 458 if (udev->state == USB_STATE_NOTATTACHED) 459 return -ENODEV; 460 if (udev->state == USB_STATE_SUSPENDED) 461 return -EHOSTUNREACH; 462 if (iface) { 463 switch (iface->condition) { 464 case USB_INTERFACE_BINDING: 465 return 0; 466 case USB_INTERFACE_BOUND: 467 break; 468 default: 469 return -EINTR; 470 } 471 } 472 473 while (usb_trylock_device(udev) != 0) { 474 475 /* If we can't acquire the lock after waiting one second, 476 * we're probably deadlocked */ 477 if (time_after(jiffies, jiffies_expire)) 478 return -EBUSY; 479 480 msleep(15); 481 if (udev->state == USB_STATE_NOTATTACHED) 482 return -ENODEV; 483 if (udev->state == USB_STATE_SUSPENDED) 484 return -EHOSTUNREACH; 485 if (iface && iface->condition != USB_INTERFACE_BOUND) 486 return -EINTR; 487 } 488 return 1; 489} 490 491 492static struct usb_device *match_device(struct usb_device *dev, 493 u16 vendor_id, u16 product_id) 494{ 495 struct usb_device *ret_dev = NULL; 496 int child; 497 498 dev_dbg(&dev->dev, "check for vendor %04x, product %04x ...\n", 499 le16_to_cpu(dev->descriptor.idVendor), 500 le16_to_cpu(dev->descriptor.idProduct)); 501 502 /* see if this device matches */ 503 if ((vendor_id == le16_to_cpu(dev->descriptor.idVendor)) && 504 (product_id == le16_to_cpu(dev->descriptor.idProduct))) { 505 dev_dbg(&dev->dev, "matched this device!\n"); 506 ret_dev = usb_get_dev(dev); 507 goto exit; 508 } 509 510 /* look through all of the children of this device */ 511 for (child = 0; child < dev->maxchild; ++child) { 512 if (dev->children[child]) { 513 usb_lock_device(dev->children[child]); 514 ret_dev = match_device(dev->children[child], 515 vendor_id, product_id); 516 usb_unlock_device(dev->children[child]); 517 if (ret_dev) 518 goto exit; 519 } 520 } 521exit: 522 return ret_dev; 523} 524 525/** 526 * usb_find_device - find a specific usb device in the system 527 * @vendor_id: the vendor id of the device to find 528 * @product_id: the product id of the device to find 529 * 530 * Returns a pointer to a struct usb_device if such a specified usb 531 * device is present in the system currently. The usage count of the 532 * device will be incremented if a device is found. Make sure to call 533 * usb_put_dev() when the caller is finished with the device. 534 * 535 * If a device with the specified vendor and product id is not found, 536 * NULL is returned. 537 */ 538struct usb_device *usb_find_device(u16 vendor_id, u16 product_id) 539{ 540 struct list_head *buslist; 541 struct usb_bus *bus; 542 struct usb_device *dev = NULL; 543 544 mutex_lock(&usb_bus_list_lock); 545 for (buslist = usb_bus_list.next; 546 buslist != &usb_bus_list; 547 buslist = buslist->next) { 548 bus = container_of(buslist, struct usb_bus, bus_list); 549 if (!bus->root_hub) 550 continue; 551 usb_lock_device(bus->root_hub); 552 dev = match_device(bus->root_hub, vendor_id, product_id); 553 usb_unlock_device(bus->root_hub); 554 if (dev) 555 goto exit; 556 } 557exit: 558 mutex_unlock(&usb_bus_list_lock); 559 return dev; 560} 561 562/** 563 * usb_get_current_frame_number - return current bus frame number 564 * @dev: the device whose bus is being queried 565 * 566 * Returns the current frame number for the USB host controller 567 * used with the given USB device. This can be used when scheduling 568 * isochronous requests. 569 * 570 * Note that different kinds of host controller have different 571 * "scheduling horizons". While one type might support scheduling only 572 * 32 frames into the future, others could support scheduling up to 573 * 1024 frames into the future. 574 */ 575int usb_get_current_frame_number(struct usb_device *dev) 576{ 577 return usb_hcd_get_frame_number(dev); 578} 579 580/*-------------------------------------------------------------------*/ 581/* 582 * __usb_get_extra_descriptor() finds a descriptor of specific type in the 583 * extra field of the interface and endpoint descriptor structs. 584 */ 585 586int __usb_get_extra_descriptor(char *buffer, unsigned size, 587 unsigned char type, void **ptr) 588{ 589 struct usb_descriptor_header *header; 590 591 while (size >= sizeof(struct usb_descriptor_header)) { 592 header = (struct usb_descriptor_header *)buffer; 593 594 if (header->bLength < 2) { 595 printk(KERN_ERR 596 "%s: bogus descriptor, type %d length %d\n", 597 usbcore_name, 598 header->bDescriptorType, 599 header->bLength); 600 return -1; 601 } 602 603 if (header->bDescriptorType == type) { 604 *ptr = header; 605 return 0; 606 } 607 608 buffer += header->bLength; 609 size -= header->bLength; 610 } 611 return -1; 612} 613 614/** 615 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP 616 * @dev: device the buffer will be used with 617 * @size: requested buffer size 618 * @mem_flags: affect whether allocation may block 619 * @dma: used to return DMA address of buffer 620 * 621 * Return value is either null (indicating no buffer could be allocated), or 622 * the cpu-space pointer to a buffer that may be used to perform DMA to the 623 * specified device. Such cpu-space buffers are returned along with the DMA 624 * address (through the pointer provided). 625 * 626 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags 627 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU 628 * hardware during URB completion/resubmit. The implementation varies between 629 * platforms, depending on details of how DMA will work to this device. 630 * Using these buffers also eliminates cacheline sharing problems on 631 * architectures where CPU caches are not DMA-coherent. On systems without 632 * bus-snooping caches, these buffers are uncached. 633 * 634 * When the buffer is no longer used, free it with usb_buffer_free(). 635 */ 636void *usb_buffer_alloc( 637 struct usb_device *dev, 638 size_t size, 639 gfp_t mem_flags, 640 dma_addr_t *dma 641) 642{ 643 if (!dev || !dev->bus) 644 return NULL; 645 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma); 646} 647 648/** 649 * usb_buffer_free - free memory allocated with usb_buffer_alloc() 650 * @dev: device the buffer was used with 651 * @size: requested buffer size 652 * @addr: CPU address of buffer 653 * @dma: DMA address of buffer 654 * 655 * This reclaims an I/O buffer, letting it be reused. The memory must have 656 * been allocated using usb_buffer_alloc(), and the parameters must match 657 * those provided in that allocation request. 658 */ 659void usb_buffer_free( 660 struct usb_device *dev, 661 size_t size, 662 void *addr, 663 dma_addr_t dma 664) 665{ 666 if (!dev || !dev->bus) 667 return; 668 if (!addr) 669 return; 670 hcd_buffer_free(dev->bus, size, addr, dma); 671} 672 673/** 674 * usb_buffer_map - create DMA mapping(s) for an urb 675 * @urb: urb whose transfer_buffer/setup_packet will be mapped 676 * 677 * Return value is either null (indicating no buffer could be mapped), or 678 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are 679 * added to urb->transfer_flags if the operation succeeds. If the device 680 * is connected to this system through a non-DMA controller, this operation 681 * always succeeds. 682 * 683 * This call would normally be used for an urb which is reused, perhaps 684 * as the target of a large periodic transfer, with usb_buffer_dmasync() 685 * calls to synchronize memory and dma state. 686 * 687 * Reverse the effect of this call with usb_buffer_unmap(). 688 */ 689#if 0 690struct urb *usb_buffer_map(struct urb *urb) 691{ 692 struct usb_bus *bus; 693 struct device *controller; 694 695 if (!urb 696 || !urb->dev 697 || !(bus = urb->dev->bus) 698 || !(controller = bus->controller)) 699 return NULL; 700 701 if (controller->dma_mask) { 702 urb->transfer_dma = dma_map_single(controller, 703 urb->transfer_buffer, urb->transfer_buffer_length, 704 usb_pipein(urb->pipe) 705 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 706 if (usb_pipecontrol(urb->pipe)) 707 urb->setup_dma = dma_map_single(controller, 708 urb->setup_packet, 709 sizeof(struct usb_ctrlrequest), 710 DMA_TO_DEVICE); 711 // FIXME generic api broken like pci, can't report errors 712 // if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; 713 } else 714 urb->transfer_dma = ~0; 715 urb->transfer_flags |= (URB_NO_TRANSFER_DMA_MAP 716 | URB_NO_SETUP_DMA_MAP); 717 return urb; 718} 719#endif /* 0 */ 720 721/* XXX DISABLED, no users currently. If you wish to re-enable this 722 * XXX please determine whether the sync is to transfer ownership of 723 * XXX the buffer from device to cpu or vice verse, and thusly use the 724 * XXX appropriate _for_{cpu,device}() method. -DaveM 725 */ 726#if 0 727 728/** 729 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s) 730 * @urb: urb whose transfer_buffer/setup_packet will be synchronized 731 */ 732void usb_buffer_dmasync(struct urb *urb) 733{ 734 struct usb_bus *bus; 735 struct device *controller; 736 737 if (!urb 738 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) 739 || !urb->dev 740 || !(bus = urb->dev->bus) 741 || !(controller = bus->controller)) 742 return; 743 744 if (controller->dma_mask) { 745 dma_sync_single(controller, 746 urb->transfer_dma, urb->transfer_buffer_length, 747 usb_pipein(urb->pipe) 748 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 749 if (usb_pipecontrol(urb->pipe)) 750 dma_sync_single(controller, 751 urb->setup_dma, 752 sizeof(struct usb_ctrlrequest), 753 DMA_TO_DEVICE); 754 } 755} 756#endif 757 758/** 759 * usb_buffer_unmap - free DMA mapping(s) for an urb 760 * @urb: urb whose transfer_buffer will be unmapped 761 * 762 * Reverses the effect of usb_buffer_map(). 763 */ 764#if 0 765void usb_buffer_unmap(struct urb *urb) 766{ 767 struct usb_bus *bus; 768 struct device *controller; 769 770 if (!urb 771 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) 772 || !urb->dev 773 || !(bus = urb->dev->bus) 774 || !(controller = bus->controller)) 775 return; 776 777 if (controller->dma_mask) { 778 dma_unmap_single(controller, 779 urb->transfer_dma, urb->transfer_buffer_length, 780 usb_pipein(urb->pipe) 781 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 782 if (usb_pipecontrol(urb->pipe)) 783 dma_unmap_single(controller, 784 urb->setup_dma, 785 sizeof(struct usb_ctrlrequest), 786 DMA_TO_DEVICE); 787 } 788 urb->transfer_flags &= ~(URB_NO_TRANSFER_DMA_MAP 789 | URB_NO_SETUP_DMA_MAP); 790} 791#endif /* 0 */ 792 793/** 794 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint 795 * @dev: device to which the scatterlist will be mapped 796 * @is_in: mapping transfer direction 797 * @sg: the scatterlist to map 798 * @nents: the number of entries in the scatterlist 799 * 800 * Return value is either < 0 (indicating no buffers could be mapped), or 801 * the number of DMA mapping array entries in the scatterlist. 802 * 803 * The caller is responsible for placing the resulting DMA addresses from 804 * the scatterlist into URB transfer buffer pointers, and for setting the 805 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs. 806 * 807 * Top I/O rates come from queuing URBs, instead of waiting for each one 808 * to complete before starting the next I/O. This is particularly easy 809 * to do with scatterlists. Just allocate and submit one URB for each DMA 810 * mapping entry returned, stopping on the first error or when all succeed. 811 * Better yet, use the usb_sg_*() calls, which do that (and more) for you. 812 * 813 * This call would normally be used when translating scatterlist requests, 814 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it 815 * may be able to coalesce mappings for improved I/O efficiency. 816 * 817 * Reverse the effect of this call with usb_buffer_unmap_sg(). 818 */ 819int usb_buffer_map_sg(const struct usb_device *dev, int is_in, 820 struct scatterlist *sg, int nents) 821{ 822 struct usb_bus *bus; 823 struct device *controller; 824 825 if (!dev 826 || !(bus = dev->bus) 827 || !(controller = bus->controller) 828 || !controller->dma_mask) 829 return -1; 830 831 // FIXME generic api broken like pci, can't report errors 832 return dma_map_sg(controller, sg, nents, 833 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 834} 835 836/* XXX DISABLED, no users currently. If you wish to re-enable this 837 * XXX please determine whether the sync is to transfer ownership of 838 * XXX the buffer from device to cpu or vice verse, and thusly use the 839 * XXX appropriate _for_{cpu,device}() method. -DaveM 840 */ 841#if 0 842 843/** 844 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s) 845 * @dev: device to which the scatterlist will be mapped 846 * @is_in: mapping transfer direction 847 * @sg: the scatterlist to synchronize 848 * @n_hw_ents: the positive return value from usb_buffer_map_sg 849 * 850 * Use this when you are re-using a scatterlist's data buffers for 851 * another USB request. 852 */ 853void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in, 854 struct scatterlist *sg, int n_hw_ents) 855{ 856 struct usb_bus *bus; 857 struct device *controller; 858 859 if (!dev 860 || !(bus = dev->bus) 861 || !(controller = bus->controller) 862 || !controller->dma_mask) 863 return; 864 865 dma_sync_sg(controller, sg, n_hw_ents, 866 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 867} 868#endif 869 870/** 871 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist 872 * @dev: device to which the scatterlist will be mapped 873 * @is_in: mapping transfer direction 874 * @sg: the scatterlist to unmap 875 * @n_hw_ents: the positive return value from usb_buffer_map_sg 876 * 877 * Reverses the effect of usb_buffer_map_sg(). 878 */ 879void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in, 880 struct scatterlist *sg, int n_hw_ents) 881{ 882 struct usb_bus *bus; 883 struct device *controller; 884 885 if (!dev 886 || !(bus = dev->bus) 887 || !(controller = bus->controller) 888 || !controller->dma_mask) 889 return; 890 891 dma_unmap_sg(controller, sg, n_hw_ents, 892 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 893} 894 895/* format to disable USB on kernel command line is: nousb */ 896__module_param_call("", nousb, param_set_bool, param_get_bool, &nousb, 0444); 897 898/* 899 * for external read access to <nousb> 900 */ 901int usb_disabled(void) 902{ 903 return nousb; 904} 905 906/* 907 * Init 908 */ 909static int __init usb_init(void) 910{ 911 int retval; 912 if (nousb) { 913 pr_info("%s: USB support disabled\n", usbcore_name); 914 return 0; 915 } 916 917 retval = ksuspend_usb_init(); 918 if (retval) 919 goto out; 920 retval = bus_register(&usb_bus_type); 921 if (retval) 922 goto bus_register_failed; 923 retval = usb_host_init(); 924 if (retval) 925 goto host_init_failed; 926 retval = usb_major_init(); 927 if (retval) 928 goto major_init_failed; 929 retval = usb_register(&usbfs_driver); 930 if (retval) 931 goto driver_register_failed; 932 retval = usb_devio_init(); 933 if (retval) 934 goto usb_devio_init_failed; 935 retval = usbfs_init(); 936 if (retval) 937 goto fs_init_failed; 938 retval = usb_hub_init(); 939 if (retval) 940 goto hub_init_failed; 941 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE); 942 if (!retval) 943 goto out; 944 945 usb_hub_cleanup(); 946hub_init_failed: 947 usbfs_cleanup(); 948fs_init_failed: 949 usb_devio_cleanup(); 950usb_devio_init_failed: 951 usb_deregister(&usbfs_driver); 952driver_register_failed: 953 usb_major_cleanup(); 954major_init_failed: 955 usb_host_cleanup(); 956host_init_failed: 957 bus_unregister(&usb_bus_type); 958bus_register_failed: 959 ksuspend_usb_cleanup(); 960out: 961 return retval; 962} 963 964/* 965 * Cleanup 966 */ 967static void __exit usb_exit(void) 968{ 969 /* This will matter if shutdown/reboot does exitcalls. */ 970 if (nousb) 971 return; 972 973 usb_deregister_device_driver(&usb_generic_driver); 974 usb_major_cleanup(); 975 usbfs_cleanup(); 976 usb_deregister(&usbfs_driver); 977 usb_devio_cleanup(); 978 usb_hub_cleanup(); 979 usb_host_cleanup(); 980 bus_unregister(&usb_bus_type); 981 ksuspend_usb_cleanup(); 982} 983 984subsys_initcall(usb_init); 985module_exit(usb_exit); 986 987/* 988 * USB may be built into the kernel or be built as modules. 989 * These symbols are exported for device (or host controller) 990 * driver modules to use. 991 */ 992 993EXPORT_SYMBOL(usb_disabled); 994 995EXPORT_SYMBOL_GPL(usb_get_intf); 996EXPORT_SYMBOL_GPL(usb_put_intf); 997 998EXPORT_SYMBOL(usb_put_dev); 999EXPORT_SYMBOL(usb_get_dev); 1000EXPORT_SYMBOL(usb_hub_tt_clear_buffer); 1001 1002EXPORT_SYMBOL(usb_lock_device_for_reset); 1003 1004EXPORT_SYMBOL(usb_find_interface); 1005EXPORT_SYMBOL(usb_ifnum_to_if); 1006EXPORT_SYMBOL(usb_altnum_to_altsetting); 1007 1008EXPORT_SYMBOL(__usb_get_extra_descriptor); 1009 1010EXPORT_SYMBOL(usb_get_current_frame_number); 1011 1012EXPORT_SYMBOL(usb_buffer_alloc); 1013EXPORT_SYMBOL(usb_buffer_free); 1014 1015#if 0 1016EXPORT_SYMBOL(usb_buffer_map); 1017EXPORT_SYMBOL(usb_buffer_dmasync); 1018EXPORT_SYMBOL(usb_buffer_unmap); 1019#endif 1020 1021EXPORT_SYMBOL(usb_buffer_map_sg); 1022#if 0 1023EXPORT_SYMBOL(usb_buffer_dmasync_sg); 1024#endif 1025EXPORT_SYMBOL(usb_buffer_unmap_sg); 1026 1027MODULE_LICENSE("GPL"); 1028