usb.c revision f5691d70d4aeec0ac9cff11f0cabb7d5a1735705
1/* 2 * drivers/usb/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/config.h> 25#include <linux/module.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 37#include <asm/io.h> 38#include <asm/scatterlist.h> 39#include <linux/mm.h> 40#include <linux/dma-mapping.h> 41 42#include "hcd.h" 43#include "usb.h" 44 45 46const char *usbcore_name = "usbcore"; 47 48static int nousb; /* Disable USB when built into kernel image */ 49 50 51/** 52 * usb_ifnum_to_if - get the interface object with a given interface number 53 * @dev: the device whose current configuration is considered 54 * @ifnum: the desired interface 55 * 56 * This walks the device descriptor for the currently active configuration 57 * and returns a pointer to the interface with that particular interface 58 * number, or null. 59 * 60 * Note that configuration descriptors are not required to assign interface 61 * numbers sequentially, so that it would be incorrect to assume that 62 * the first interface in that descriptor corresponds to interface zero. 63 * This routine helps device drivers avoid such mistakes. 64 * However, you should make sure that you do the right thing with any 65 * alternate settings available for this interfaces. 66 * 67 * Don't call this function unless you are bound to one of the interfaces 68 * on this device or you have locked the device! 69 */ 70struct usb_interface *usb_ifnum_to_if(struct usb_device *dev, unsigned ifnum) 71{ 72 struct usb_host_config *config = dev->actconfig; 73 int i; 74 75 if (!config) 76 return NULL; 77 for (i = 0; i < config->desc.bNumInterfaces; i++) 78 if (config->interface[i]->altsetting[0] 79 .desc.bInterfaceNumber == ifnum) 80 return config->interface[i]; 81 82 return NULL; 83} 84 85/** 86 * usb_altnum_to_altsetting - get the altsetting structure with a given 87 * alternate setting number. 88 * @intf: the interface containing the altsetting in question 89 * @altnum: the desired alternate setting number 90 * 91 * This searches the altsetting array of the specified interface for 92 * an entry with the correct bAlternateSetting value and returns a pointer 93 * to that entry, or null. 94 * 95 * Note that altsettings need not be stored sequentially by number, so 96 * it would be incorrect to assume that the first altsetting entry in 97 * the array corresponds to altsetting zero. This routine helps device 98 * drivers avoid such mistakes. 99 * 100 * Don't call this function unless you are bound to the intf interface 101 * or you have locked the device! 102 */ 103struct usb_host_interface *usb_altnum_to_altsetting(struct usb_interface *intf, 104 unsigned int altnum) 105{ 106 int i; 107 108 for (i = 0; i < intf->num_altsetting; i++) { 109 if (intf->altsetting[i].desc.bAlternateSetting == altnum) 110 return &intf->altsetting[i]; 111 } 112 return NULL; 113} 114 115/** 116 * usb_driver_claim_interface - bind a driver to an interface 117 * @driver: the driver to be bound 118 * @iface: the interface to which it will be bound; must be in the 119 * usb device's active configuration 120 * @priv: driver data associated with that interface 121 * 122 * This is used by usb device drivers that need to claim more than one 123 * interface on a device when probing (audio and acm are current examples). 124 * No device driver should directly modify internal usb_interface or 125 * usb_device structure members. 126 * 127 * Few drivers should need to use this routine, since the most natural 128 * way to bind to an interface is to return the private data from 129 * the driver's probe() method. 130 * 131 * Callers must own the device lock and the driver model's usb_bus_type.subsys 132 * writelock. So driver probe() entries don't need extra locking, 133 * but other call contexts may need to explicitly claim those locks. 134 */ 135int usb_driver_claim_interface(struct usb_driver *driver, 136 struct usb_interface *iface, void* priv) 137{ 138 struct device *dev = &iface->dev; 139 140 if (dev->driver) 141 return -EBUSY; 142 143 dev->driver = &driver->driver; 144 usb_set_intfdata(iface, priv); 145 iface->condition = USB_INTERFACE_BOUND; 146 mark_active(iface); 147 148 /* if interface was already added, bind now; else let 149 * the future device_add() bind it, bypassing probe() 150 */ 151 if (device_is_registered(dev)) 152 device_bind_driver(dev); 153 154 return 0; 155} 156 157/** 158 * usb_driver_release_interface - unbind a driver from an interface 159 * @driver: the driver to be unbound 160 * @iface: the interface from which it will be unbound 161 * 162 * This can be used by drivers to release an interface without waiting 163 * for their disconnect() methods to be called. In typical cases this 164 * also causes the driver disconnect() method to be called. 165 * 166 * This call is synchronous, and may not be used in an interrupt context. 167 * Callers must own the device lock and the driver model's usb_bus_type.subsys 168 * writelock. So driver disconnect() entries don't need extra locking, 169 * but other call contexts may need to explicitly claim those locks. 170 */ 171void usb_driver_release_interface(struct usb_driver *driver, 172 struct usb_interface *iface) 173{ 174 struct device *dev = &iface->dev; 175 176 /* this should never happen, don't release something that's not ours */ 177 if (!dev->driver || dev->driver != &driver->driver) 178 return; 179 180 /* don't release from within disconnect() */ 181 if (iface->condition != USB_INTERFACE_BOUND) 182 return; 183 184 /* don't release if the interface hasn't been added yet */ 185 if (device_is_registered(dev)) { 186 iface->condition = USB_INTERFACE_UNBINDING; 187 device_release_driver(dev); 188 } 189 190 dev->driver = NULL; 191 usb_set_intfdata(iface, NULL); 192 iface->condition = USB_INTERFACE_UNBOUND; 193 mark_quiesced(iface); 194} 195struct find_interface_arg { 196 int minor; 197 struct usb_interface *interface; 198}; 199 200static int __find_interface(struct device * dev, void * data) 201{ 202 struct find_interface_arg *arg = data; 203 struct usb_interface *intf; 204 205 /* can't look at usb devices, only interfaces */ 206 if (dev->driver == &usb_generic_driver) 207 return 0; 208 209 intf = to_usb_interface(dev); 210 if (intf->minor != -1 && intf->minor == arg->minor) { 211 arg->interface = intf; 212 return 1; 213 } 214 return 0; 215} 216 217/** 218 * usb_find_interface - find usb_interface pointer for driver and device 219 * @drv: the driver whose current configuration is considered 220 * @minor: the minor number of the desired device 221 * 222 * This walks the driver device list and returns a pointer to the interface 223 * with the matching minor. Note, this only works for devices that share the 224 * USB major number. 225 */ 226struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor) 227{ 228 struct find_interface_arg argb; 229 230 argb.minor = minor; 231 argb.interface = NULL; 232 driver_for_each_device(&drv->driver, NULL, &argb, __find_interface); 233 return argb.interface; 234} 235 236#ifdef CONFIG_HOTPLUG 237 238/* 239 * USB hotplugging invokes what /proc/sys/kernel/hotplug says 240 * (normally /sbin/hotplug) when USB devices get added or removed. 241 * 242 * This invokes a user mode policy agent, typically helping to load driver 243 * or other modules, configure the device, and more. Drivers can provide 244 * a MODULE_DEVICE_TABLE to help with module loading subtasks. 245 * 246 * We're called either from khubd (the typical case) or from root hub 247 * (init, kapmd, modprobe, rmmod, etc), but the agents need to handle 248 * delays in event delivery. Use sysfs (and DEVPATH) to make sure the 249 * device (and this configuration!) are still present. 250 */ 251static int usb_hotplug (struct device *dev, char **envp, int num_envp, 252 char *buffer, int buffer_size) 253{ 254 struct usb_interface *intf; 255 struct usb_device *usb_dev; 256 struct usb_host_interface *alt; 257 int i = 0; 258 int length = 0; 259 260 if (!dev) 261 return -ENODEV; 262 263 /* driver is often null here; dev_dbg() would oops */ 264 pr_debug ("usb %s: hotplug\n", dev->bus_id); 265 266 /* Must check driver_data here, as on remove driver is always NULL */ 267 if ((dev->driver == &usb_generic_driver) || 268 (dev->driver_data == &usb_generic_driver_data)) 269 return 0; 270 271 intf = to_usb_interface(dev); 272 usb_dev = interface_to_usbdev (intf); 273 alt = intf->cur_altsetting; 274 275 if (usb_dev->devnum < 0) { 276 pr_debug ("usb %s: already deleted?\n", dev->bus_id); 277 return -ENODEV; 278 } 279 if (!usb_dev->bus) { 280 pr_debug ("usb %s: bus removed?\n", dev->bus_id); 281 return -ENODEV; 282 } 283 284#ifdef CONFIG_USB_DEVICEFS 285 /* If this is available, userspace programs can directly read 286 * all the device descriptors we don't tell them about. Or 287 * even act as usermode drivers. 288 * 289 * FIXME reduce hardwired intelligence here 290 */ 291 if (add_hotplug_env_var(envp, num_envp, &i, 292 buffer, buffer_size, &length, 293 "DEVICE=/proc/bus/usb/%03d/%03d", 294 usb_dev->bus->busnum, usb_dev->devnum)) 295 return -ENOMEM; 296#endif 297 298 /* per-device configurations are common */ 299 if (add_hotplug_env_var(envp, num_envp, &i, 300 buffer, buffer_size, &length, 301 "PRODUCT=%x/%x/%x", 302 le16_to_cpu(usb_dev->descriptor.idVendor), 303 le16_to_cpu(usb_dev->descriptor.idProduct), 304 le16_to_cpu(usb_dev->descriptor.bcdDevice))) 305 return -ENOMEM; 306 307 /* class-based driver binding models */ 308 if (add_hotplug_env_var(envp, num_envp, &i, 309 buffer, buffer_size, &length, 310 "TYPE=%d/%d/%d", 311 usb_dev->descriptor.bDeviceClass, 312 usb_dev->descriptor.bDeviceSubClass, 313 usb_dev->descriptor.bDeviceProtocol)) 314 return -ENOMEM; 315 316 if (add_hotplug_env_var(envp, num_envp, &i, 317 buffer, buffer_size, &length, 318 "INTERFACE=%d/%d/%d", 319 alt->desc.bInterfaceClass, 320 alt->desc.bInterfaceSubClass, 321 alt->desc.bInterfaceProtocol)) 322 return -ENOMEM; 323 324 if (add_hotplug_env_var(envp, num_envp, &i, 325 buffer, buffer_size, &length, 326 "MODALIAS=usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02X", 327 le16_to_cpu(usb_dev->descriptor.idVendor), 328 le16_to_cpu(usb_dev->descriptor.idProduct), 329 le16_to_cpu(usb_dev->descriptor.bcdDevice), 330 usb_dev->descriptor.bDeviceClass, 331 usb_dev->descriptor.bDeviceSubClass, 332 usb_dev->descriptor.bDeviceProtocol, 333 alt->desc.bInterfaceClass, 334 alt->desc.bInterfaceSubClass, 335 alt->desc.bInterfaceProtocol)) 336 return -ENOMEM; 337 338 envp[i] = NULL; 339 340 return 0; 341} 342 343#else 344 345static int usb_hotplug (struct device *dev, char **envp, 346 int num_envp, char *buffer, int buffer_size) 347{ 348 return -ENODEV; 349} 350 351#endif /* CONFIG_HOTPLUG */ 352 353/** 354 * usb_release_dev - free a usb device structure when all users of it are finished. 355 * @dev: device that's been disconnected 356 * 357 * Will be called only by the device core when all users of this usb device are 358 * done. 359 */ 360static void usb_release_dev(struct device *dev) 361{ 362 struct usb_device *udev; 363 364 udev = to_usb_device(dev); 365 366 usb_destroy_configuration(udev); 367 usb_bus_put(udev->bus); 368 kfree(udev->product); 369 kfree(udev->manufacturer); 370 kfree(udev->serial); 371 kfree(udev); 372} 373 374/** 375 * usb_alloc_dev - usb device constructor (usbcore-internal) 376 * @parent: hub to which device is connected; null to allocate a root hub 377 * @bus: bus used to access the device 378 * @port1: one-based index of port; ignored for root hubs 379 * Context: !in_interrupt () 380 * 381 * Only hub drivers (including virtual root hub drivers for host 382 * controllers) should ever call this. 383 * 384 * This call may not be used in a non-sleeping context. 385 */ 386struct usb_device * 387usb_alloc_dev(struct usb_device *parent, struct usb_bus *bus, unsigned port1) 388{ 389 struct usb_device *dev; 390 391 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 392 if (!dev) 393 return NULL; 394 395 bus = usb_bus_get(bus); 396 if (!bus) { 397 kfree(dev); 398 return NULL; 399 } 400 401 device_initialize(&dev->dev); 402 dev->dev.bus = &usb_bus_type; 403 dev->dev.dma_mask = bus->controller->dma_mask; 404 dev->dev.driver_data = &usb_generic_driver_data; 405 dev->dev.driver = &usb_generic_driver; 406 dev->dev.release = usb_release_dev; 407 dev->state = USB_STATE_ATTACHED; 408 409 INIT_LIST_HEAD(&dev->ep0.urb_list); 410 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE; 411 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT; 412 /* ep0 maxpacket comes later, from device descriptor */ 413 dev->ep_in[0] = dev->ep_out[0] = &dev->ep0; 414 415 /* Save readable and stable topology id, distinguishing devices 416 * by location for diagnostics, tools, driver model, etc. The 417 * string is a path along hub ports, from the root. Each device's 418 * dev->devpath will be stable until USB is re-cabled, and hubs 419 * are often labeled with these port numbers. The bus_id isn't 420 * as stable: bus->busnum changes easily from modprobe order, 421 * cardbus or pci hotplugging, and so on. 422 */ 423 if (unlikely (!parent)) { 424 dev->devpath [0] = '0'; 425 426 dev->dev.parent = bus->controller; 427 sprintf (&dev->dev.bus_id[0], "usb%d", bus->busnum); 428 } else { 429 /* match any labeling on the hubs; it's one-based */ 430 if (parent->devpath [0] == '0') 431 snprintf (dev->devpath, sizeof dev->devpath, 432 "%d", port1); 433 else 434 snprintf (dev->devpath, sizeof dev->devpath, 435 "%s.%d", parent->devpath, port1); 436 437 dev->dev.parent = &parent->dev; 438 sprintf (&dev->dev.bus_id[0], "%d-%s", 439 bus->busnum, dev->devpath); 440 441 /* hub driver sets up TT records */ 442 } 443 444 dev->portnum = port1; 445 dev->bus = bus; 446 dev->parent = parent; 447 INIT_LIST_HEAD(&dev->filelist); 448 449 return dev; 450} 451 452/** 453 * usb_get_dev - increments the reference count of the usb device structure 454 * @dev: the device being referenced 455 * 456 * Each live reference to a device should be refcounted. 457 * 458 * Drivers for USB interfaces should normally record such references in 459 * their probe() methods, when they bind to an interface, and release 460 * them by calling usb_put_dev(), in their disconnect() methods. 461 * 462 * A pointer to the device with the incremented reference counter is returned. 463 */ 464struct usb_device *usb_get_dev(struct usb_device *dev) 465{ 466 if (dev) 467 get_device(&dev->dev); 468 return dev; 469} 470 471/** 472 * usb_put_dev - release a use of the usb device structure 473 * @dev: device that's been disconnected 474 * 475 * Must be called when a user of a device is finished with it. When the last 476 * user of the device calls this function, the memory of the device is freed. 477 */ 478void usb_put_dev(struct usb_device *dev) 479{ 480 if (dev) 481 put_device(&dev->dev); 482} 483 484/** 485 * usb_get_intf - increments the reference count of the usb interface structure 486 * @intf: the interface being referenced 487 * 488 * Each live reference to a interface must be refcounted. 489 * 490 * Drivers for USB interfaces should normally record such references in 491 * their probe() methods, when they bind to an interface, and release 492 * them by calling usb_put_intf(), in their disconnect() methods. 493 * 494 * A pointer to the interface with the incremented reference counter is 495 * returned. 496 */ 497struct usb_interface *usb_get_intf(struct usb_interface *intf) 498{ 499 if (intf) 500 get_device(&intf->dev); 501 return intf; 502} 503 504/** 505 * usb_put_intf - release a use of the usb interface structure 506 * @intf: interface that's been decremented 507 * 508 * Must be called when a user of an interface is finished with it. When the 509 * last user of the interface calls this function, the memory of the interface 510 * is freed. 511 */ 512void usb_put_intf(struct usb_interface *intf) 513{ 514 if (intf) 515 put_device(&intf->dev); 516} 517 518 519/* USB device locking 520 * 521 * USB devices and interfaces are locked using the semaphore in their 522 * embedded struct device. The hub driver guarantees that whenever a 523 * device is connected or disconnected, drivers are called with the 524 * USB device locked as well as their particular interface. 525 * 526 * Complications arise when several devices are to be locked at the same 527 * time. Only hub-aware drivers that are part of usbcore ever have to 528 * do this; nobody else needs to worry about it. The rule for locking 529 * is simple: 530 * 531 * When locking both a device and its parent, always lock the 532 * the parent first. 533 */ 534 535/** 536 * usb_lock_device_for_reset - cautiously acquire the lock for a 537 * usb device structure 538 * @udev: device that's being locked 539 * @iface: interface bound to the driver making the request (optional) 540 * 541 * Attempts to acquire the device lock, but fails if the device is 542 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface 543 * is neither BINDING nor BOUND. Rather than sleeping to wait for the 544 * lock, the routine polls repeatedly. This is to prevent deadlock with 545 * disconnect; in some drivers (such as usb-storage) the disconnect() 546 * or suspend() method will block waiting for a device reset to complete. 547 * 548 * Returns a negative error code for failure, otherwise 1 or 0 to indicate 549 * that the device will or will not have to be unlocked. (0 can be 550 * returned when an interface is given and is BINDING, because in that 551 * case the driver already owns the device lock.) 552 */ 553int usb_lock_device_for_reset(struct usb_device *udev, 554 struct usb_interface *iface) 555{ 556 unsigned long jiffies_expire = jiffies + HZ; 557 558 if (udev->state == USB_STATE_NOTATTACHED) 559 return -ENODEV; 560 if (udev->state == USB_STATE_SUSPENDED) 561 return -EHOSTUNREACH; 562 if (iface) { 563 switch (iface->condition) { 564 case USB_INTERFACE_BINDING: 565 return 0; 566 case USB_INTERFACE_BOUND: 567 break; 568 default: 569 return -EINTR; 570 } 571 } 572 573 while (usb_trylock_device(udev) != 0) { 574 575 /* If we can't acquire the lock after waiting one second, 576 * we're probably deadlocked */ 577 if (time_after(jiffies, jiffies_expire)) 578 return -EBUSY; 579 580 msleep(15); 581 if (udev->state == USB_STATE_NOTATTACHED) 582 return -ENODEV; 583 if (udev->state == USB_STATE_SUSPENDED) 584 return -EHOSTUNREACH; 585 if (iface && iface->condition != USB_INTERFACE_BOUND) 586 return -EINTR; 587 } 588 return 1; 589} 590 591 592static struct usb_device *match_device(struct usb_device *dev, 593 u16 vendor_id, u16 product_id) 594{ 595 struct usb_device *ret_dev = NULL; 596 int child; 597 598 dev_dbg(&dev->dev, "check for vendor %04x, product %04x ...\n", 599 le16_to_cpu(dev->descriptor.idVendor), 600 le16_to_cpu(dev->descriptor.idProduct)); 601 602 /* see if this device matches */ 603 if ((vendor_id == le16_to_cpu(dev->descriptor.idVendor)) && 604 (product_id == le16_to_cpu(dev->descriptor.idProduct))) { 605 dev_dbg (&dev->dev, "matched this device!\n"); 606 ret_dev = usb_get_dev(dev); 607 goto exit; 608 } 609 610 /* look through all of the children of this device */ 611 for (child = 0; child < dev->maxchild; ++child) { 612 if (dev->children[child]) { 613 usb_lock_device(dev->children[child]); 614 ret_dev = match_device(dev->children[child], 615 vendor_id, product_id); 616 usb_unlock_device(dev->children[child]); 617 if (ret_dev) 618 goto exit; 619 } 620 } 621exit: 622 return ret_dev; 623} 624 625/** 626 * usb_find_device - find a specific usb device in the system 627 * @vendor_id: the vendor id of the device to find 628 * @product_id: the product id of the device to find 629 * 630 * Returns a pointer to a struct usb_device if such a specified usb 631 * device is present in the system currently. The usage count of the 632 * device will be incremented if a device is found. Make sure to call 633 * usb_put_dev() when the caller is finished with the device. 634 * 635 * If a device with the specified vendor and product id is not found, 636 * NULL is returned. 637 */ 638struct usb_device *usb_find_device(u16 vendor_id, u16 product_id) 639{ 640 struct list_head *buslist; 641 struct usb_bus *bus; 642 struct usb_device *dev = NULL; 643 644 down(&usb_bus_list_lock); 645 for (buslist = usb_bus_list.next; 646 buslist != &usb_bus_list; 647 buslist = buslist->next) { 648 bus = container_of(buslist, struct usb_bus, bus_list); 649 if (!bus->root_hub) 650 continue; 651 usb_lock_device(bus->root_hub); 652 dev = match_device(bus->root_hub, vendor_id, product_id); 653 usb_unlock_device(bus->root_hub); 654 if (dev) 655 goto exit; 656 } 657exit: 658 up(&usb_bus_list_lock); 659 return dev; 660} 661 662/** 663 * usb_get_current_frame_number - return current bus frame number 664 * @dev: the device whose bus is being queried 665 * 666 * Returns the current frame number for the USB host controller 667 * used with the given USB device. This can be used when scheduling 668 * isochronous requests. 669 * 670 * Note that different kinds of host controller have different 671 * "scheduling horizons". While one type might support scheduling only 672 * 32 frames into the future, others could support scheduling up to 673 * 1024 frames into the future. 674 */ 675int usb_get_current_frame_number(struct usb_device *dev) 676{ 677 return dev->bus->op->get_frame_number (dev); 678} 679 680/*-------------------------------------------------------------------*/ 681/* 682 * __usb_get_extra_descriptor() finds a descriptor of specific type in the 683 * extra field of the interface and endpoint descriptor structs. 684 */ 685 686int __usb_get_extra_descriptor(char *buffer, unsigned size, 687 unsigned char type, void **ptr) 688{ 689 struct usb_descriptor_header *header; 690 691 while (size >= sizeof(struct usb_descriptor_header)) { 692 header = (struct usb_descriptor_header *)buffer; 693 694 if (header->bLength < 2) { 695 printk(KERN_ERR 696 "%s: bogus descriptor, type %d length %d\n", 697 usbcore_name, 698 header->bDescriptorType, 699 header->bLength); 700 return -1; 701 } 702 703 if (header->bDescriptorType == type) { 704 *ptr = header; 705 return 0; 706 } 707 708 buffer += header->bLength; 709 size -= header->bLength; 710 } 711 return -1; 712} 713 714/** 715 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP 716 * @dev: device the buffer will be used with 717 * @size: requested buffer size 718 * @mem_flags: affect whether allocation may block 719 * @dma: used to return DMA address of buffer 720 * 721 * Return value is either null (indicating no buffer could be allocated), or 722 * the cpu-space pointer to a buffer that may be used to perform DMA to the 723 * specified device. Such cpu-space buffers are returned along with the DMA 724 * address (through the pointer provided). 725 * 726 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags 727 * to avoid behaviors like using "DMA bounce buffers", or tying down I/O 728 * mapping hardware for long idle periods. The implementation varies between 729 * platforms, depending on details of how DMA will work to this device. 730 * Using these buffers also helps prevent cacheline sharing problems on 731 * architectures where CPU caches are not DMA-coherent. 732 * 733 * When the buffer is no longer used, free it with usb_buffer_free(). 734 */ 735void *usb_buffer_alloc ( 736 struct usb_device *dev, 737 size_t size, 738 gfp_t mem_flags, 739 dma_addr_t *dma 740) 741{ 742 if (!dev || !dev->bus || !dev->bus->op || !dev->bus->op->buffer_alloc) 743 return NULL; 744 return dev->bus->op->buffer_alloc (dev->bus, size, mem_flags, dma); 745} 746 747/** 748 * usb_buffer_free - free memory allocated with usb_buffer_alloc() 749 * @dev: device the buffer was used with 750 * @size: requested buffer size 751 * @addr: CPU address of buffer 752 * @dma: DMA address of buffer 753 * 754 * This reclaims an I/O buffer, letting it be reused. The memory must have 755 * been allocated using usb_buffer_alloc(), and the parameters must match 756 * those provided in that allocation request. 757 */ 758void usb_buffer_free ( 759 struct usb_device *dev, 760 size_t size, 761 void *addr, 762 dma_addr_t dma 763) 764{ 765 if (!dev || !dev->bus || !dev->bus->op || !dev->bus->op->buffer_free) 766 return; 767 dev->bus->op->buffer_free (dev->bus, size, addr, dma); 768} 769 770/** 771 * usb_buffer_map - create DMA mapping(s) for an urb 772 * @urb: urb whose transfer_buffer/setup_packet will be mapped 773 * 774 * Return value is either null (indicating no buffer could be mapped), or 775 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are 776 * added to urb->transfer_flags if the operation succeeds. If the device 777 * is connected to this system through a non-DMA controller, this operation 778 * always succeeds. 779 * 780 * This call would normally be used for an urb which is reused, perhaps 781 * as the target of a large periodic transfer, with usb_buffer_dmasync() 782 * calls to synchronize memory and dma state. 783 * 784 * Reverse the effect of this call with usb_buffer_unmap(). 785 */ 786#if 0 787struct urb *usb_buffer_map (struct urb *urb) 788{ 789 struct usb_bus *bus; 790 struct device *controller; 791 792 if (!urb 793 || !urb->dev 794 || !(bus = urb->dev->bus) 795 || !(controller = bus->controller)) 796 return NULL; 797 798 if (controller->dma_mask) { 799 urb->transfer_dma = dma_map_single (controller, 800 urb->transfer_buffer, urb->transfer_buffer_length, 801 usb_pipein (urb->pipe) 802 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 803 if (usb_pipecontrol (urb->pipe)) 804 urb->setup_dma = dma_map_single (controller, 805 urb->setup_packet, 806 sizeof (struct usb_ctrlrequest), 807 DMA_TO_DEVICE); 808 // FIXME generic api broken like pci, can't report errors 809 // if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; 810 } else 811 urb->transfer_dma = ~0; 812 urb->transfer_flags |= (URB_NO_TRANSFER_DMA_MAP 813 | URB_NO_SETUP_DMA_MAP); 814 return urb; 815} 816#endif /* 0 */ 817 818/* XXX DISABLED, no users currently. If you wish to re-enable this 819 * XXX please determine whether the sync is to transfer ownership of 820 * XXX the buffer from device to cpu or vice verse, and thusly use the 821 * XXX appropriate _for_{cpu,device}() method. -DaveM 822 */ 823#if 0 824 825/** 826 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s) 827 * @urb: urb whose transfer_buffer/setup_packet will be synchronized 828 */ 829void usb_buffer_dmasync (struct urb *urb) 830{ 831 struct usb_bus *bus; 832 struct device *controller; 833 834 if (!urb 835 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) 836 || !urb->dev 837 || !(bus = urb->dev->bus) 838 || !(controller = bus->controller)) 839 return; 840 841 if (controller->dma_mask) { 842 dma_sync_single (controller, 843 urb->transfer_dma, urb->transfer_buffer_length, 844 usb_pipein (urb->pipe) 845 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 846 if (usb_pipecontrol (urb->pipe)) 847 dma_sync_single (controller, 848 urb->setup_dma, 849 sizeof (struct usb_ctrlrequest), 850 DMA_TO_DEVICE); 851 } 852} 853#endif 854 855/** 856 * usb_buffer_unmap - free DMA mapping(s) for an urb 857 * @urb: urb whose transfer_buffer will be unmapped 858 * 859 * Reverses the effect of usb_buffer_map(). 860 */ 861#if 0 862void usb_buffer_unmap (struct urb *urb) 863{ 864 struct usb_bus *bus; 865 struct device *controller; 866 867 if (!urb 868 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) 869 || !urb->dev 870 || !(bus = urb->dev->bus) 871 || !(controller = bus->controller)) 872 return; 873 874 if (controller->dma_mask) { 875 dma_unmap_single (controller, 876 urb->transfer_dma, urb->transfer_buffer_length, 877 usb_pipein (urb->pipe) 878 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 879 if (usb_pipecontrol (urb->pipe)) 880 dma_unmap_single (controller, 881 urb->setup_dma, 882 sizeof (struct usb_ctrlrequest), 883 DMA_TO_DEVICE); 884 } 885 urb->transfer_flags &= ~(URB_NO_TRANSFER_DMA_MAP 886 | URB_NO_SETUP_DMA_MAP); 887} 888#endif /* 0 */ 889 890/** 891 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint 892 * @dev: device to which the scatterlist will be mapped 893 * @pipe: endpoint defining the mapping direction 894 * @sg: the scatterlist to map 895 * @nents: the number of entries in the scatterlist 896 * 897 * Return value is either < 0 (indicating no buffers could be mapped), or 898 * the number of DMA mapping array entries in the scatterlist. 899 * 900 * The caller is responsible for placing the resulting DMA addresses from 901 * the scatterlist into URB transfer buffer pointers, and for setting the 902 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs. 903 * 904 * Top I/O rates come from queuing URBs, instead of waiting for each one 905 * to complete before starting the next I/O. This is particularly easy 906 * to do with scatterlists. Just allocate and submit one URB for each DMA 907 * mapping entry returned, stopping on the first error or when all succeed. 908 * Better yet, use the usb_sg_*() calls, which do that (and more) for you. 909 * 910 * This call would normally be used when translating scatterlist requests, 911 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it 912 * may be able to coalesce mappings for improved I/O efficiency. 913 * 914 * Reverse the effect of this call with usb_buffer_unmap_sg(). 915 */ 916int usb_buffer_map_sg (struct usb_device *dev, unsigned pipe, 917 struct scatterlist *sg, int nents) 918{ 919 struct usb_bus *bus; 920 struct device *controller; 921 922 if (!dev 923 || usb_pipecontrol (pipe) 924 || !(bus = dev->bus) 925 || !(controller = bus->controller) 926 || !controller->dma_mask) 927 return -1; 928 929 // FIXME generic api broken like pci, can't report errors 930 return dma_map_sg (controller, sg, nents, 931 usb_pipein (pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 932} 933 934/* XXX DISABLED, no users currently. If you wish to re-enable this 935 * XXX please determine whether the sync is to transfer ownership of 936 * XXX the buffer from device to cpu or vice verse, and thusly use the 937 * XXX appropriate _for_{cpu,device}() method. -DaveM 938 */ 939#if 0 940 941/** 942 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s) 943 * @dev: device to which the scatterlist will be mapped 944 * @pipe: endpoint defining the mapping direction 945 * @sg: the scatterlist to synchronize 946 * @n_hw_ents: the positive return value from usb_buffer_map_sg 947 * 948 * Use this when you are re-using a scatterlist's data buffers for 949 * another USB request. 950 */ 951void usb_buffer_dmasync_sg (struct usb_device *dev, unsigned pipe, 952 struct scatterlist *sg, int n_hw_ents) 953{ 954 struct usb_bus *bus; 955 struct device *controller; 956 957 if (!dev 958 || !(bus = dev->bus) 959 || !(controller = bus->controller) 960 || !controller->dma_mask) 961 return; 962 963 dma_sync_sg (controller, sg, n_hw_ents, 964 usb_pipein (pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 965} 966#endif 967 968/** 969 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist 970 * @dev: device to which the scatterlist will be mapped 971 * @pipe: endpoint defining the mapping direction 972 * @sg: the scatterlist to unmap 973 * @n_hw_ents: the positive return value from usb_buffer_map_sg 974 * 975 * Reverses the effect of usb_buffer_map_sg(). 976 */ 977void usb_buffer_unmap_sg (struct usb_device *dev, unsigned pipe, 978 struct scatterlist *sg, int n_hw_ents) 979{ 980 struct usb_bus *bus; 981 struct device *controller; 982 983 if (!dev 984 || !(bus = dev->bus) 985 || !(controller = bus->controller) 986 || !controller->dma_mask) 987 return; 988 989 dma_unmap_sg (controller, sg, n_hw_ents, 990 usb_pipein (pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 991} 992 993static int verify_suspended(struct device *dev, void *unused) 994{ 995 return (dev->power.power_state.event == PM_EVENT_ON) ? -EBUSY : 0; 996} 997 998static int usb_generic_suspend(struct device *dev, pm_message_t message) 999{ 1000 struct usb_interface *intf; 1001 struct usb_driver *driver; 1002 int status; 1003 1004 /* USB devices enter SUSPEND state through their hubs, but can be 1005 * marked for FREEZE as soon as their children are already idled. 1006 * But those semantics are useless, so we equate the two (sigh). 1007 */ 1008 if (dev->driver == &usb_generic_driver) { 1009 if (dev->power.power_state.event == message.event) 1010 return 0; 1011 /* we need to rule out bogus requests through sysfs */ 1012 status = device_for_each_child(dev, NULL, verify_suspended); 1013 if (status) 1014 return status; 1015 return usb_suspend_device (to_usb_device(dev)); 1016 } 1017 1018 if ((dev->driver == NULL) || 1019 (dev->driver_data == &usb_generic_driver_data)) 1020 return 0; 1021 1022 intf = to_usb_interface(dev); 1023 driver = to_usb_driver(dev->driver); 1024 1025 /* with no hardware, USB interfaces only use FREEZE and ON states */ 1026 if (!is_active(intf)) 1027 return 0; 1028 1029 if (driver->suspend && driver->resume) { 1030 status = driver->suspend(intf, message); 1031 if (status) 1032 dev_err(dev, "%s error %d\n", "suspend", status); 1033 else 1034 mark_quiesced(intf); 1035 } else { 1036 // FIXME else if there's no suspend method, disconnect... 1037 dev_warn(dev, "no suspend for driver %s?\n", driver->name); 1038 mark_quiesced(intf); 1039 status = 0; 1040 } 1041 return status; 1042} 1043 1044static int usb_generic_resume(struct device *dev) 1045{ 1046 struct usb_interface *intf; 1047 struct usb_driver *driver; 1048 struct usb_device *udev; 1049 int status; 1050 1051 if (dev->power.power_state.event == PM_EVENT_ON) 1052 return 0; 1053 1054 /* mark things as "on" immediately, no matter what errors crop up */ 1055 dev->power.power_state.event = PM_EVENT_ON; 1056 1057 /* devices resume through their hubs */ 1058 if (dev->driver == &usb_generic_driver) { 1059 udev = to_usb_device(dev); 1060 if (udev->state == USB_STATE_NOTATTACHED) 1061 return 0; 1062 return usb_resume_device (to_usb_device(dev)); 1063 } 1064 1065 if ((dev->driver == NULL) || 1066 (dev->driver_data == &usb_generic_driver_data)) { 1067 dev->power.power_state.event = PM_EVENT_FREEZE; 1068 return 0; 1069 } 1070 1071 intf = to_usb_interface(dev); 1072 driver = to_usb_driver(dev->driver); 1073 1074 udev = interface_to_usbdev(intf); 1075 if (udev->state == USB_STATE_NOTATTACHED) 1076 return 0; 1077 1078 /* if driver was suspended, it has a resume method; 1079 * however, sysfs can wrongly mark things as suspended 1080 * (on the "no suspend method" FIXME path above) 1081 */ 1082 if (driver->resume) { 1083 status = driver->resume(intf); 1084 if (status) { 1085 dev_err(dev, "%s error %d\n", "resume", status); 1086 mark_quiesced(intf); 1087 } 1088 } else 1089 dev_warn(dev, "no resume for driver %s?\n", driver->name); 1090 return 0; 1091} 1092 1093struct bus_type usb_bus_type = { 1094 .name = "usb", 1095 .match = usb_device_match, 1096 .hotplug = usb_hotplug, 1097 .suspend = usb_generic_suspend, 1098 .resume = usb_generic_resume, 1099}; 1100 1101/* format to disable USB on kernel command line is: nousb */ 1102__module_param_call("", nousb, param_set_bool, param_get_bool, &nousb, 0444); 1103 1104/* 1105 * for external read access to <nousb> 1106 */ 1107int usb_disabled(void) 1108{ 1109 return nousb; 1110} 1111 1112/* 1113 * Init 1114 */ 1115static int __init usb_init(void) 1116{ 1117 int retval; 1118 if (nousb) { 1119 pr_info ("%s: USB support disabled\n", usbcore_name); 1120 return 0; 1121 } 1122 1123 retval = bus_register(&usb_bus_type); 1124 if (retval) 1125 goto out; 1126 retval = usb_host_init(); 1127 if (retval) 1128 goto host_init_failed; 1129 retval = usb_major_init(); 1130 if (retval) 1131 goto major_init_failed; 1132 retval = usb_register(&usbfs_driver); 1133 if (retval) 1134 goto driver_register_failed; 1135 retval = usbdev_init(); 1136 if (retval) 1137 goto usbdevice_init_failed; 1138 retval = usbfs_init(); 1139 if (retval) 1140 goto fs_init_failed; 1141 retval = usb_hub_init(); 1142 if (retval) 1143 goto hub_init_failed; 1144 retval = driver_register(&usb_generic_driver); 1145 if (!retval) 1146 goto out; 1147 1148 usb_hub_cleanup(); 1149hub_init_failed: 1150 usbfs_cleanup(); 1151fs_init_failed: 1152 usbdev_cleanup(); 1153usbdevice_init_failed: 1154 usb_deregister(&usbfs_driver); 1155driver_register_failed: 1156 usb_major_cleanup(); 1157major_init_failed: 1158 usb_host_cleanup(); 1159host_init_failed: 1160 bus_unregister(&usb_bus_type); 1161out: 1162 return retval; 1163} 1164 1165/* 1166 * Cleanup 1167 */ 1168static void __exit usb_exit(void) 1169{ 1170 /* This will matter if shutdown/reboot does exitcalls. */ 1171 if (nousb) 1172 return; 1173 1174 driver_unregister(&usb_generic_driver); 1175 usb_major_cleanup(); 1176 usbfs_cleanup(); 1177 usb_deregister(&usbfs_driver); 1178 usbdev_cleanup(); 1179 usb_hub_cleanup(); 1180 usb_host_cleanup(); 1181 bus_unregister(&usb_bus_type); 1182} 1183 1184subsys_initcall(usb_init); 1185module_exit(usb_exit); 1186 1187/* 1188 * USB may be built into the kernel or be built as modules. 1189 * These symbols are exported for device (or host controller) 1190 * driver modules to use. 1191 */ 1192 1193EXPORT_SYMBOL(usb_disabled); 1194 1195EXPORT_SYMBOL_GPL(usb_get_intf); 1196EXPORT_SYMBOL_GPL(usb_put_intf); 1197 1198EXPORT_SYMBOL(usb_alloc_dev); 1199EXPORT_SYMBOL(usb_put_dev); 1200EXPORT_SYMBOL(usb_get_dev); 1201EXPORT_SYMBOL(usb_hub_tt_clear_buffer); 1202 1203EXPORT_SYMBOL(usb_lock_device_for_reset); 1204 1205EXPORT_SYMBOL(usb_driver_claim_interface); 1206EXPORT_SYMBOL(usb_driver_release_interface); 1207EXPORT_SYMBOL(usb_find_interface); 1208EXPORT_SYMBOL(usb_ifnum_to_if); 1209EXPORT_SYMBOL(usb_altnum_to_altsetting); 1210 1211EXPORT_SYMBOL(usb_reset_device); 1212EXPORT_SYMBOL(usb_disconnect); 1213 1214EXPORT_SYMBOL(__usb_get_extra_descriptor); 1215 1216EXPORT_SYMBOL(usb_find_device); 1217EXPORT_SYMBOL(usb_get_current_frame_number); 1218 1219EXPORT_SYMBOL (usb_buffer_alloc); 1220EXPORT_SYMBOL (usb_buffer_free); 1221 1222#if 0 1223EXPORT_SYMBOL (usb_buffer_map); 1224EXPORT_SYMBOL (usb_buffer_dmasync); 1225EXPORT_SYMBOL (usb_buffer_unmap); 1226#endif 1227 1228EXPORT_SYMBOL (usb_buffer_map_sg); 1229#if 0 1230EXPORT_SYMBOL (usb_buffer_dmasync_sg); 1231#endif 1232EXPORT_SYMBOL (usb_buffer_unmap_sg); 1233 1234MODULE_LICENSE("GPL"); 1235