usb.c revision b5e795f8df42936590ba9c606edc715fe3593284
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/smp_lock.h> 35#include <linux/usb.h> 36#include <linux/mutex.h> 37#include <linux/workqueue.h> 38 39#include <asm/io.h> 40#include <asm/scatterlist.h> 41#include <linux/mm.h> 42#include <linux/dma-mapping.h> 43 44#include "hcd.h" 45#include "usb.h" 46 47 48const char *usbcore_name = "usbcore"; 49 50static int nousb; /* Disable USB when built into kernel image */ 51 52struct workqueue_struct *ksuspend_usb_wq; /* For autosuspend */ 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, uint, 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#ifdef CONFIG_USB_SUSPEND 188 cancel_delayed_work(&udev->autosuspend); 189 flush_workqueue(ksuspend_usb_wq); 190#endif 191 usb_destroy_configuration(udev); 192 usb_put_hcd(bus_to_hcd(udev->bus)); 193 kfree(udev->product); 194 kfree(udev->manufacturer); 195 kfree(udev->serial); 196 kfree(udev); 197} 198 199#ifdef CONFIG_PM 200 201static int ksuspend_usb_init(void) 202{ 203 ksuspend_usb_wq = create_singlethread_workqueue("ksuspend_usbd"); 204 if (!ksuspend_usb_wq) 205 return -ENOMEM; 206 return 0; 207} 208 209static void ksuspend_usb_cleanup(void) 210{ 211 destroy_workqueue(ksuspend_usb_wq); 212} 213 214#ifdef CONFIG_USB_SUSPEND 215 216/* usb_autosuspend_work - callback routine to autosuspend a USB device */ 217static void usb_autosuspend_work(struct work_struct *work) 218{ 219 struct usb_device *udev = 220 container_of(work, struct usb_device, autosuspend.work); 221 222 usb_pm_lock(udev); 223 udev->auto_pm = 1; 224 usb_suspend_both(udev, PMSG_SUSPEND); 225 usb_pm_unlock(udev); 226} 227 228#else 229 230static void usb_autosuspend_work(struct work_struct *work) 231{} 232 233#endif /* CONFIG_USB_SUSPEND */ 234 235#else 236 237#define ksuspend_usb_init() 0 238#define ksuspend_usb_cleanup() do {} while (0) 239 240#endif /* CONFIG_PM */ 241 242/** 243 * usb_alloc_dev - usb device constructor (usbcore-internal) 244 * @parent: hub to which device is connected; null to allocate a root hub 245 * @bus: bus used to access the device 246 * @port1: one-based index of port; ignored for root hubs 247 * Context: !in_interrupt() 248 * 249 * Only hub drivers (including virtual root hub drivers for host 250 * controllers) should ever call this. 251 * 252 * This call may not be used in a non-sleeping context. 253 */ 254struct usb_device * 255usb_alloc_dev(struct usb_device *parent, struct usb_bus *bus, unsigned port1) 256{ 257 struct usb_device *dev; 258 259 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 260 if (!dev) 261 return NULL; 262 263 if (!usb_get_hcd(bus_to_hcd(bus))) { 264 kfree(dev); 265 return NULL; 266 } 267 268 device_initialize(&dev->dev); 269 dev->dev.bus = &usb_bus_type; 270 dev->dev.dma_mask = bus->controller->dma_mask; 271 dev->dev.release = usb_release_dev; 272 dev->state = USB_STATE_ATTACHED; 273 274 /* This magic assignment distinguishes devices from interfaces */ 275 dev->dev.platform_data = &usb_generic_driver; 276 277 INIT_LIST_HEAD(&dev->ep0.urb_list); 278 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE; 279 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT; 280 /* ep0 maxpacket comes later, from device descriptor */ 281 dev->ep_in[0] = dev->ep_out[0] = &dev->ep0; 282 283 /* Save readable and stable topology id, distinguishing devices 284 * by location for diagnostics, tools, driver model, etc. The 285 * string is a path along hub ports, from the root. Each device's 286 * dev->devpath will be stable until USB is re-cabled, and hubs 287 * are often labeled with these port numbers. The bus_id isn't 288 * as stable: bus->busnum changes easily from modprobe order, 289 * cardbus or pci hotplugging, and so on. 290 */ 291 if (unlikely(!parent)) { 292 dev->devpath[0] = '0'; 293 294 dev->dev.parent = bus->controller; 295 sprintf(&dev->dev.bus_id[0], "usb%d", bus->busnum); 296 } else { 297 /* match any labeling on the hubs; it's one-based */ 298 if (parent->devpath[0] == '0') 299 snprintf(dev->devpath, sizeof dev->devpath, 300 "%d", port1); 301 else 302 snprintf(dev->devpath, sizeof dev->devpath, 303 "%s.%d", parent->devpath, port1); 304 305 dev->dev.parent = &parent->dev; 306 sprintf(&dev->dev.bus_id[0], "%d-%s", 307 bus->busnum, dev->devpath); 308 309 /* hub driver sets up TT records */ 310 } 311 312 dev->portnum = port1; 313 dev->bus = bus; 314 dev->parent = parent; 315 INIT_LIST_HEAD(&dev->filelist); 316 317#ifdef CONFIG_PM 318 mutex_init(&dev->pm_mutex); 319 INIT_DELAYED_WORK(&dev->autosuspend, usb_autosuspend_work); 320 dev->autosuspend_delay = usb_autosuspend_delay * HZ; 321#endif 322 return dev; 323} 324 325/** 326 * usb_get_dev - increments the reference count of the usb device structure 327 * @dev: the device being referenced 328 * 329 * Each live reference to a device should be refcounted. 330 * 331 * Drivers for USB interfaces should normally record such references in 332 * their probe() methods, when they bind to an interface, and release 333 * them by calling usb_put_dev(), in their disconnect() methods. 334 * 335 * A pointer to the device with the incremented reference counter is returned. 336 */ 337struct usb_device *usb_get_dev(struct usb_device *dev) 338{ 339 if (dev) 340 get_device(&dev->dev); 341 return dev; 342} 343 344/** 345 * usb_put_dev - release a use of the usb device structure 346 * @dev: device that's been disconnected 347 * 348 * Must be called when a user of a device is finished with it. When the last 349 * user of the device calls this function, the memory of the device is freed. 350 */ 351void usb_put_dev(struct usb_device *dev) 352{ 353 if (dev) 354 put_device(&dev->dev); 355} 356 357/** 358 * usb_get_intf - increments the reference count of the usb interface structure 359 * @intf: the interface being referenced 360 * 361 * Each live reference to a interface must be refcounted. 362 * 363 * Drivers for USB interfaces should normally record such references in 364 * their probe() methods, when they bind to an interface, and release 365 * them by calling usb_put_intf(), in their disconnect() methods. 366 * 367 * A pointer to the interface with the incremented reference counter is 368 * returned. 369 */ 370struct usb_interface *usb_get_intf(struct usb_interface *intf) 371{ 372 if (intf) 373 get_device(&intf->dev); 374 return intf; 375} 376 377/** 378 * usb_put_intf - release a use of the usb interface structure 379 * @intf: interface that's been decremented 380 * 381 * Must be called when a user of an interface is finished with it. When the 382 * last user of the interface calls this function, the memory of the interface 383 * is freed. 384 */ 385void usb_put_intf(struct usb_interface *intf) 386{ 387 if (intf) 388 put_device(&intf->dev); 389} 390 391 392/* USB device locking 393 * 394 * USB devices and interfaces are locked using the semaphore in their 395 * embedded struct device. The hub driver guarantees that whenever a 396 * device is connected or disconnected, drivers are called with the 397 * USB device locked as well as their particular interface. 398 * 399 * Complications arise when several devices are to be locked at the same 400 * time. Only hub-aware drivers that are part of usbcore ever have to 401 * do this; nobody else needs to worry about it. The rule for locking 402 * is simple: 403 * 404 * When locking both a device and its parent, always lock the 405 * the parent first. 406 */ 407 408/** 409 * usb_lock_device_for_reset - cautiously acquire the lock for a 410 * usb device structure 411 * @udev: device that's being locked 412 * @iface: interface bound to the driver making the request (optional) 413 * 414 * Attempts to acquire the device lock, but fails if the device is 415 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface 416 * is neither BINDING nor BOUND. Rather than sleeping to wait for the 417 * lock, the routine polls repeatedly. This is to prevent deadlock with 418 * disconnect; in some drivers (such as usb-storage) the disconnect() 419 * or suspend() method will block waiting for a device reset to complete. 420 * 421 * Returns a negative error code for failure, otherwise 1 or 0 to indicate 422 * that the device will or will not have to be unlocked. (0 can be 423 * returned when an interface is given and is BINDING, because in that 424 * case the driver already owns the device lock.) 425 */ 426int usb_lock_device_for_reset(struct usb_device *udev, 427 const struct usb_interface *iface) 428{ 429 unsigned long jiffies_expire = jiffies + HZ; 430 431 if (udev->state == USB_STATE_NOTATTACHED) 432 return -ENODEV; 433 if (udev->state == USB_STATE_SUSPENDED) 434 return -EHOSTUNREACH; 435 if (iface) { 436 switch (iface->condition) { 437 case USB_INTERFACE_BINDING: 438 return 0; 439 case USB_INTERFACE_BOUND: 440 break; 441 default: 442 return -EINTR; 443 } 444 } 445 446 while (usb_trylock_device(udev) != 0) { 447 448 /* If we can't acquire the lock after waiting one second, 449 * we're probably deadlocked */ 450 if (time_after(jiffies, jiffies_expire)) 451 return -EBUSY; 452 453 msleep(15); 454 if (udev->state == USB_STATE_NOTATTACHED) 455 return -ENODEV; 456 if (udev->state == USB_STATE_SUSPENDED) 457 return -EHOSTUNREACH; 458 if (iface && iface->condition != USB_INTERFACE_BOUND) 459 return -EINTR; 460 } 461 return 1; 462} 463 464 465static struct usb_device *match_device(struct usb_device *dev, 466 u16 vendor_id, u16 product_id) 467{ 468 struct usb_device *ret_dev = NULL; 469 int child; 470 471 dev_dbg(&dev->dev, "check for vendor %04x, product %04x ...\n", 472 le16_to_cpu(dev->descriptor.idVendor), 473 le16_to_cpu(dev->descriptor.idProduct)); 474 475 /* see if this device matches */ 476 if ((vendor_id == le16_to_cpu(dev->descriptor.idVendor)) && 477 (product_id == le16_to_cpu(dev->descriptor.idProduct))) { 478 dev_dbg(&dev->dev, "matched this device!\n"); 479 ret_dev = usb_get_dev(dev); 480 goto exit; 481 } 482 483 /* look through all of the children of this device */ 484 for (child = 0; child < dev->maxchild; ++child) { 485 if (dev->children[child]) { 486 usb_lock_device(dev->children[child]); 487 ret_dev = match_device(dev->children[child], 488 vendor_id, product_id); 489 usb_unlock_device(dev->children[child]); 490 if (ret_dev) 491 goto exit; 492 } 493 } 494exit: 495 return ret_dev; 496} 497 498/** 499 * usb_find_device - find a specific usb device in the system 500 * @vendor_id: the vendor id of the device to find 501 * @product_id: the product id of the device to find 502 * 503 * Returns a pointer to a struct usb_device if such a specified usb 504 * device is present in the system currently. The usage count of the 505 * device will be incremented if a device is found. Make sure to call 506 * usb_put_dev() when the caller is finished with the device. 507 * 508 * If a device with the specified vendor and product id is not found, 509 * NULL is returned. 510 */ 511struct usb_device *usb_find_device(u16 vendor_id, u16 product_id) 512{ 513 struct list_head *buslist; 514 struct usb_bus *bus; 515 struct usb_device *dev = NULL; 516 517 mutex_lock(&usb_bus_list_lock); 518 for (buslist = usb_bus_list.next; 519 buslist != &usb_bus_list; 520 buslist = buslist->next) { 521 bus = container_of(buslist, struct usb_bus, bus_list); 522 if (!bus->root_hub) 523 continue; 524 usb_lock_device(bus->root_hub); 525 dev = match_device(bus->root_hub, vendor_id, product_id); 526 usb_unlock_device(bus->root_hub); 527 if (dev) 528 goto exit; 529 } 530exit: 531 mutex_unlock(&usb_bus_list_lock); 532 return dev; 533} 534 535/** 536 * usb_get_current_frame_number - return current bus frame number 537 * @dev: the device whose bus is being queried 538 * 539 * Returns the current frame number for the USB host controller 540 * used with the given USB device. This can be used when scheduling 541 * isochronous requests. 542 * 543 * Note that different kinds of host controller have different 544 * "scheduling horizons". While one type might support scheduling only 545 * 32 frames into the future, others could support scheduling up to 546 * 1024 frames into the future. 547 */ 548int usb_get_current_frame_number(struct usb_device *dev) 549{ 550 return usb_hcd_get_frame_number(dev); 551} 552 553/*-------------------------------------------------------------------*/ 554/* 555 * __usb_get_extra_descriptor() finds a descriptor of specific type in the 556 * extra field of the interface and endpoint descriptor structs. 557 */ 558 559int __usb_get_extra_descriptor(char *buffer, unsigned size, 560 unsigned char type, void **ptr) 561{ 562 struct usb_descriptor_header *header; 563 564 while (size >= sizeof(struct usb_descriptor_header)) { 565 header = (struct usb_descriptor_header *)buffer; 566 567 if (header->bLength < 2) { 568 printk(KERN_ERR 569 "%s: bogus descriptor, type %d length %d\n", 570 usbcore_name, 571 header->bDescriptorType, 572 header->bLength); 573 return -1; 574 } 575 576 if (header->bDescriptorType == type) { 577 *ptr = header; 578 return 0; 579 } 580 581 buffer += header->bLength; 582 size -= header->bLength; 583 } 584 return -1; 585} 586 587/** 588 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP 589 * @dev: device the buffer will be used with 590 * @size: requested buffer size 591 * @mem_flags: affect whether allocation may block 592 * @dma: used to return DMA address of buffer 593 * 594 * Return value is either null (indicating no buffer could be allocated), or 595 * the cpu-space pointer to a buffer that may be used to perform DMA to the 596 * specified device. Such cpu-space buffers are returned along with the DMA 597 * address (through the pointer provided). 598 * 599 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags 600 * to avoid behaviors like using "DMA bounce buffers", or tying down I/O 601 * mapping hardware for long idle periods. The implementation varies between 602 * platforms, depending on details of how DMA will work to this device. 603 * Using these buffers also helps prevent cacheline sharing problems on 604 * architectures where CPU caches are not DMA-coherent. 605 * 606 * When the buffer is no longer used, free it with usb_buffer_free(). 607 */ 608void *usb_buffer_alloc( 609 struct usb_device *dev, 610 size_t size, 611 gfp_t mem_flags, 612 dma_addr_t *dma 613) 614{ 615 if (!dev || !dev->bus) 616 return NULL; 617 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma); 618} 619 620/** 621 * usb_buffer_free - free memory allocated with usb_buffer_alloc() 622 * @dev: device the buffer was used with 623 * @size: requested buffer size 624 * @addr: CPU address of buffer 625 * @dma: DMA address of buffer 626 * 627 * This reclaims an I/O buffer, letting it be reused. The memory must have 628 * been allocated using usb_buffer_alloc(), and the parameters must match 629 * those provided in that allocation request. 630 */ 631void usb_buffer_free( 632 struct usb_device *dev, 633 size_t size, 634 void *addr, 635 dma_addr_t dma 636) 637{ 638 if (!dev || !dev->bus) 639 return; 640 if (!addr) 641 return; 642 hcd_buffer_free(dev->bus, size, addr, dma); 643} 644 645/** 646 * usb_buffer_map - create DMA mapping(s) for an urb 647 * @urb: urb whose transfer_buffer/setup_packet will be mapped 648 * 649 * Return value is either null (indicating no buffer could be mapped), or 650 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are 651 * added to urb->transfer_flags if the operation succeeds. If the device 652 * is connected to this system through a non-DMA controller, this operation 653 * always succeeds. 654 * 655 * This call would normally be used for an urb which is reused, perhaps 656 * as the target of a large periodic transfer, with usb_buffer_dmasync() 657 * calls to synchronize memory and dma state. 658 * 659 * Reverse the effect of this call with usb_buffer_unmap(). 660 */ 661#if 0 662struct urb *usb_buffer_map(struct urb *urb) 663{ 664 struct usb_bus *bus; 665 struct device *controller; 666 667 if (!urb 668 || !urb->dev 669 || !(bus = urb->dev->bus) 670 || !(controller = bus->controller)) 671 return NULL; 672 673 if (controller->dma_mask) { 674 urb->transfer_dma = dma_map_single(controller, 675 urb->transfer_buffer, urb->transfer_buffer_length, 676 usb_pipein(urb->pipe) 677 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 678 if (usb_pipecontrol(urb->pipe)) 679 urb->setup_dma = dma_map_single(controller, 680 urb->setup_packet, 681 sizeof(struct usb_ctrlrequest), 682 DMA_TO_DEVICE); 683 // FIXME generic api broken like pci, can't report errors 684 // if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; 685 } else 686 urb->transfer_dma = ~0; 687 urb->transfer_flags |= (URB_NO_TRANSFER_DMA_MAP 688 | URB_NO_SETUP_DMA_MAP); 689 return urb; 690} 691#endif /* 0 */ 692 693/* XXX DISABLED, no users currently. If you wish to re-enable this 694 * XXX please determine whether the sync is to transfer ownership of 695 * XXX the buffer from device to cpu or vice verse, and thusly use the 696 * XXX appropriate _for_{cpu,device}() method. -DaveM 697 */ 698#if 0 699 700/** 701 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s) 702 * @urb: urb whose transfer_buffer/setup_packet will be synchronized 703 */ 704void usb_buffer_dmasync(struct urb *urb) 705{ 706 struct usb_bus *bus; 707 struct device *controller; 708 709 if (!urb 710 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) 711 || !urb->dev 712 || !(bus = urb->dev->bus) 713 || !(controller = bus->controller)) 714 return; 715 716 if (controller->dma_mask) { 717 dma_sync_single(controller, 718 urb->transfer_dma, urb->transfer_buffer_length, 719 usb_pipein(urb->pipe) 720 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 721 if (usb_pipecontrol(urb->pipe)) 722 dma_sync_single(controller, 723 urb->setup_dma, 724 sizeof(struct usb_ctrlrequest), 725 DMA_TO_DEVICE); 726 } 727} 728#endif 729 730/** 731 * usb_buffer_unmap - free DMA mapping(s) for an urb 732 * @urb: urb whose transfer_buffer will be unmapped 733 * 734 * Reverses the effect of usb_buffer_map(). 735 */ 736#if 0 737void usb_buffer_unmap(struct urb *urb) 738{ 739 struct usb_bus *bus; 740 struct device *controller; 741 742 if (!urb 743 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) 744 || !urb->dev 745 || !(bus = urb->dev->bus) 746 || !(controller = bus->controller)) 747 return; 748 749 if (controller->dma_mask) { 750 dma_unmap_single(controller, 751 urb->transfer_dma, urb->transfer_buffer_length, 752 usb_pipein(urb->pipe) 753 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 754 if (usb_pipecontrol(urb->pipe)) 755 dma_unmap_single(controller, 756 urb->setup_dma, 757 sizeof(struct usb_ctrlrequest), 758 DMA_TO_DEVICE); 759 } 760 urb->transfer_flags &= ~(URB_NO_TRANSFER_DMA_MAP 761 | URB_NO_SETUP_DMA_MAP); 762} 763#endif /* 0 */ 764 765/** 766 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint 767 * @dev: device to which the scatterlist will be mapped 768 * @pipe: endpoint defining the mapping direction 769 * @sg: the scatterlist to map 770 * @nents: the number of entries in the scatterlist 771 * 772 * Return value is either < 0 (indicating no buffers could be mapped), or 773 * the number of DMA mapping array entries in the scatterlist. 774 * 775 * The caller is responsible for placing the resulting DMA addresses from 776 * the scatterlist into URB transfer buffer pointers, and for setting the 777 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs. 778 * 779 * Top I/O rates come from queuing URBs, instead of waiting for each one 780 * to complete before starting the next I/O. This is particularly easy 781 * to do with scatterlists. Just allocate and submit one URB for each DMA 782 * mapping entry returned, stopping on the first error or when all succeed. 783 * Better yet, use the usb_sg_*() calls, which do that (and more) for you. 784 * 785 * This call would normally be used when translating scatterlist requests, 786 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it 787 * may be able to coalesce mappings for improved I/O efficiency. 788 * 789 * Reverse the effect of this call with usb_buffer_unmap_sg(). 790 */ 791int usb_buffer_map_sg(const struct usb_device *dev, unsigned pipe, 792 struct scatterlist *sg, int nents) 793{ 794 struct usb_bus *bus; 795 struct device *controller; 796 797 if (!dev 798 || usb_pipecontrol(pipe) 799 || !(bus = dev->bus) 800 || !(controller = bus->controller) 801 || !controller->dma_mask) 802 return -1; 803 804 // FIXME generic api broken like pci, can't report errors 805 return dma_map_sg(controller, sg, nents, 806 usb_pipein(pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 807} 808 809/* XXX DISABLED, no users currently. If you wish to re-enable this 810 * XXX please determine whether the sync is to transfer ownership of 811 * XXX the buffer from device to cpu or vice verse, and thusly use the 812 * XXX appropriate _for_{cpu,device}() method. -DaveM 813 */ 814#if 0 815 816/** 817 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s) 818 * @dev: device to which the scatterlist will be mapped 819 * @pipe: endpoint defining the mapping direction 820 * @sg: the scatterlist to synchronize 821 * @n_hw_ents: the positive return value from usb_buffer_map_sg 822 * 823 * Use this when you are re-using a scatterlist's data buffers for 824 * another USB request. 825 */ 826void usb_buffer_dmasync_sg(const struct usb_device *dev, unsigned pipe, 827 struct scatterlist *sg, int n_hw_ents) 828{ 829 struct usb_bus *bus; 830 struct device *controller; 831 832 if (!dev 833 || !(bus = dev->bus) 834 || !(controller = bus->controller) 835 || !controller->dma_mask) 836 return; 837 838 dma_sync_sg(controller, sg, n_hw_ents, 839 usb_pipein(pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 840} 841#endif 842 843/** 844 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist 845 * @dev: device to which the scatterlist will be mapped 846 * @pipe: endpoint defining the mapping direction 847 * @sg: the scatterlist to unmap 848 * @n_hw_ents: the positive return value from usb_buffer_map_sg 849 * 850 * Reverses the effect of usb_buffer_map_sg(). 851 */ 852void usb_buffer_unmap_sg(const struct usb_device *dev, unsigned pipe, 853 struct scatterlist *sg, int n_hw_ents) 854{ 855 struct usb_bus *bus; 856 struct device *controller; 857 858 if (!dev 859 || !(bus = dev->bus) 860 || !(controller = bus->controller) 861 || !controller->dma_mask) 862 return; 863 864 dma_unmap_sg(controller, sg, n_hw_ents, 865 usb_pipein(pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 866} 867 868/* format to disable USB on kernel command line is: nousb */ 869__module_param_call("", nousb, param_set_bool, param_get_bool, &nousb, 0444); 870 871/* 872 * for external read access to <nousb> 873 */ 874int usb_disabled(void) 875{ 876 return nousb; 877} 878 879/* 880 * Init 881 */ 882static int __init usb_init(void) 883{ 884 int retval; 885 if (nousb) { 886 pr_info("%s: USB support disabled\n", usbcore_name); 887 return 0; 888 } 889 890 retval = ksuspend_usb_init(); 891 if (retval) 892 goto out; 893 retval = bus_register(&usb_bus_type); 894 if (retval) 895 goto bus_register_failed; 896 retval = usb_host_init(); 897 if (retval) 898 goto host_init_failed; 899 retval = usb_major_init(); 900 if (retval) 901 goto major_init_failed; 902 retval = usb_register(&usbfs_driver); 903 if (retval) 904 goto driver_register_failed; 905 retval = usbdev_init(); 906 if (retval) 907 goto usbdevice_init_failed; 908 retval = usbfs_init(); 909 if (retval) 910 goto fs_init_failed; 911 retval = usb_hub_init(); 912 if (retval) 913 goto hub_init_failed; 914 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE); 915 if (!retval) 916 goto out; 917 918 usb_hub_cleanup(); 919hub_init_failed: 920 usbfs_cleanup(); 921fs_init_failed: 922 usbdev_cleanup(); 923usbdevice_init_failed: 924 usb_deregister(&usbfs_driver); 925driver_register_failed: 926 usb_major_cleanup(); 927major_init_failed: 928 usb_host_cleanup(); 929host_init_failed: 930 bus_unregister(&usb_bus_type); 931bus_register_failed: 932 ksuspend_usb_cleanup(); 933out: 934 return retval; 935} 936 937/* 938 * Cleanup 939 */ 940static void __exit usb_exit(void) 941{ 942 /* This will matter if shutdown/reboot does exitcalls. */ 943 if (nousb) 944 return; 945 946 usb_deregister_device_driver(&usb_generic_driver); 947 usb_major_cleanup(); 948 usbfs_cleanup(); 949 usb_deregister(&usbfs_driver); 950 usbdev_cleanup(); 951 usb_hub_cleanup(); 952 usb_host_cleanup(); 953 bus_unregister(&usb_bus_type); 954 ksuspend_usb_cleanup(); 955} 956 957subsys_initcall(usb_init); 958module_exit(usb_exit); 959 960/* 961 * USB may be built into the kernel or be built as modules. 962 * These symbols are exported for device (or host controller) 963 * driver modules to use. 964 */ 965 966EXPORT_SYMBOL(usb_disabled); 967 968EXPORT_SYMBOL_GPL(usb_get_intf); 969EXPORT_SYMBOL_GPL(usb_put_intf); 970 971EXPORT_SYMBOL(usb_put_dev); 972EXPORT_SYMBOL(usb_get_dev); 973EXPORT_SYMBOL(usb_hub_tt_clear_buffer); 974 975EXPORT_SYMBOL(usb_lock_device_for_reset); 976 977EXPORT_SYMBOL(usb_find_interface); 978EXPORT_SYMBOL(usb_ifnum_to_if); 979EXPORT_SYMBOL(usb_altnum_to_altsetting); 980 981EXPORT_SYMBOL(__usb_get_extra_descriptor); 982 983EXPORT_SYMBOL(usb_find_device); 984EXPORT_SYMBOL(usb_get_current_frame_number); 985 986EXPORT_SYMBOL(usb_buffer_alloc); 987EXPORT_SYMBOL(usb_buffer_free); 988 989#if 0 990EXPORT_SYMBOL(usb_buffer_map); 991EXPORT_SYMBOL(usb_buffer_dmasync); 992EXPORT_SYMBOL(usb_buffer_unmap); 993#endif 994 995EXPORT_SYMBOL(usb_buffer_map_sg); 996#if 0 997EXPORT_SYMBOL(usb_buffer_dmasync_sg); 998#endif 999EXPORT_SYMBOL(usb_buffer_unmap_sg); 1000 1001MODULE_LICENSE("GPL"); 1002