usb.c revision 140d8f687457c40a66af362838fac0d7893e7df5
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/module.h> 25#include <linux/string.h> 26#include <linux/bitops.h> 27#include <linux/slab.h> 28#include <linux/interrupt.h> /* for in_interrupt() */ 29#include <linux/kmod.h> 30#include <linux/init.h> 31#include <linux/spinlock.h> 32#include <linux/errno.h> 33#include <linux/smp_lock.h> 34#include <linux/usb.h> 35#include <linux/mutex.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} 195 196struct find_interface_arg { 197 int minor; 198 struct usb_interface *interface; 199}; 200 201static int __find_interface(struct device * dev, void * data) 202{ 203 struct find_interface_arg *arg = data; 204 struct usb_interface *intf; 205 206 /* can't look at usb devices, only interfaces */ 207 if (dev->driver == &usb_generic_driver) 208 return 0; 209 210 intf = to_usb_interface(dev); 211 if (intf->minor != -1 && intf->minor == arg->minor) { 212 arg->interface = intf; 213 return 1; 214 } 215 return 0; 216} 217 218/** 219 * usb_find_interface - find usb_interface pointer for driver and device 220 * @drv: the driver whose current configuration is considered 221 * @minor: the minor number of the desired device 222 * 223 * This walks the driver device list and returns a pointer to the interface 224 * with the matching minor. Note, this only works for devices that share the 225 * USB major number. 226 */ 227struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor) 228{ 229 struct find_interface_arg argb; 230 231 argb.minor = minor; 232 argb.interface = NULL; 233 driver_for_each_device(&drv->driver, NULL, &argb, __find_interface); 234 return argb.interface; 235} 236 237#ifdef CONFIG_HOTPLUG 238 239/* 240 * This sends an uevent to userspace, typically helping to load driver 241 * or other modules, configure the device, and more. Drivers can provide 242 * a MODULE_DEVICE_TABLE to help with module loading subtasks. 243 * 244 * We're called either from khubd (the typical case) or from root hub 245 * (init, kapmd, modprobe, rmmod, etc), but the agents need to handle 246 * delays in event delivery. Use sysfs (and DEVPATH) to make sure the 247 * device (and this configuration!) are still present. 248 */ 249static int usb_uevent(struct device *dev, char **envp, int num_envp, 250 char *buffer, int buffer_size) 251{ 252 struct usb_interface *intf; 253 struct usb_device *usb_dev; 254 struct usb_host_interface *alt; 255 int i = 0; 256 int length = 0; 257 258 if (!dev) 259 return -ENODEV; 260 261 /* driver is often null here; dev_dbg() would oops */ 262 pr_debug ("usb %s: uevent\n", dev->bus_id); 263 264 /* Must check driver_data here, as on remove driver is always NULL */ 265 if ((dev->driver == &usb_generic_driver) || 266 (dev->driver_data == &usb_generic_driver_data)) 267 return 0; 268 269 intf = to_usb_interface(dev); 270 usb_dev = interface_to_usbdev (intf); 271 alt = intf->cur_altsetting; 272 273 if (usb_dev->devnum < 0) { 274 pr_debug ("usb %s: already deleted?\n", dev->bus_id); 275 return -ENODEV; 276 } 277 if (!usb_dev->bus) { 278 pr_debug ("usb %s: bus removed?\n", dev->bus_id); 279 return -ENODEV; 280 } 281 282#ifdef CONFIG_USB_DEVICEFS 283 /* If this is available, userspace programs can directly read 284 * all the device descriptors we don't tell them about. Or 285 * even act as usermode drivers. 286 * 287 * FIXME reduce hardwired intelligence here 288 */ 289 if (add_uevent_var(envp, num_envp, &i, 290 buffer, buffer_size, &length, 291 "DEVICE=/proc/bus/usb/%03d/%03d", 292 usb_dev->bus->busnum, usb_dev->devnum)) 293 return -ENOMEM; 294#endif 295 296 /* per-device configurations are common */ 297 if (add_uevent_var(envp, num_envp, &i, 298 buffer, buffer_size, &length, 299 "PRODUCT=%x/%x/%x", 300 le16_to_cpu(usb_dev->descriptor.idVendor), 301 le16_to_cpu(usb_dev->descriptor.idProduct), 302 le16_to_cpu(usb_dev->descriptor.bcdDevice))) 303 return -ENOMEM; 304 305 /* class-based driver binding models */ 306 if (add_uevent_var(envp, num_envp, &i, 307 buffer, buffer_size, &length, 308 "TYPE=%d/%d/%d", 309 usb_dev->descriptor.bDeviceClass, 310 usb_dev->descriptor.bDeviceSubClass, 311 usb_dev->descriptor.bDeviceProtocol)) 312 return -ENOMEM; 313 314 if (add_uevent_var(envp, num_envp, &i, 315 buffer, buffer_size, &length, 316 "INTERFACE=%d/%d/%d", 317 alt->desc.bInterfaceClass, 318 alt->desc.bInterfaceSubClass, 319 alt->desc.bInterfaceProtocol)) 320 return -ENOMEM; 321 322 if (add_uevent_var(envp, num_envp, &i, 323 buffer, buffer_size, &length, 324 "MODALIAS=usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02X", 325 le16_to_cpu(usb_dev->descriptor.idVendor), 326 le16_to_cpu(usb_dev->descriptor.idProduct), 327 le16_to_cpu(usb_dev->descriptor.bcdDevice), 328 usb_dev->descriptor.bDeviceClass, 329 usb_dev->descriptor.bDeviceSubClass, 330 usb_dev->descriptor.bDeviceProtocol, 331 alt->desc.bInterfaceClass, 332 alt->desc.bInterfaceSubClass, 333 alt->desc.bInterfaceProtocol)) 334 return -ENOMEM; 335 336 envp[i] = NULL; 337 338 return 0; 339} 340 341#else 342 343static int usb_uevent(struct device *dev, char **envp, 344 int num_envp, char *buffer, int buffer_size) 345{ 346 return -ENODEV; 347} 348 349#endif /* CONFIG_HOTPLUG */ 350 351/** 352 * usb_release_dev - free a usb device structure when all users of it are finished. 353 * @dev: device that's been disconnected 354 * 355 * Will be called only by the device core when all users of this usb device are 356 * done. 357 */ 358static void usb_release_dev(struct device *dev) 359{ 360 struct usb_device *udev; 361 362 udev = to_usb_device(dev); 363 364 usb_destroy_configuration(udev); 365 usb_bus_put(udev->bus); 366 kfree(udev->product); 367 kfree(udev->manufacturer); 368 kfree(udev->serial); 369 kfree(udev); 370} 371 372/** 373 * usb_alloc_dev - usb device constructor (usbcore-internal) 374 * @parent: hub to which device is connected; null to allocate a root hub 375 * @bus: bus used to access the device 376 * @port1: one-based index of port; ignored for root hubs 377 * Context: !in_interrupt () 378 * 379 * Only hub drivers (including virtual root hub drivers for host 380 * controllers) should ever call this. 381 * 382 * This call may not be used in a non-sleeping context. 383 */ 384struct usb_device * 385usb_alloc_dev(struct usb_device *parent, struct usb_bus *bus, unsigned port1) 386{ 387 struct usb_device *dev; 388 389 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 390 if (!dev) 391 return NULL; 392 393 bus = usb_bus_get(bus); 394 if (!bus) { 395 kfree(dev); 396 return NULL; 397 } 398 399 device_initialize(&dev->dev); 400 dev->dev.bus = &usb_bus_type; 401 dev->dev.dma_mask = bus->controller->dma_mask; 402 dev->dev.driver_data = &usb_generic_driver_data; 403 dev->dev.driver = &usb_generic_driver; 404 dev->dev.release = usb_release_dev; 405 dev->state = USB_STATE_ATTACHED; 406 407 INIT_LIST_HEAD(&dev->ep0.urb_list); 408 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE; 409 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT; 410 /* ep0 maxpacket comes later, from device descriptor */ 411 dev->ep_in[0] = dev->ep_out[0] = &dev->ep0; 412 413 /* Save readable and stable topology id, distinguishing devices 414 * by location for diagnostics, tools, driver model, etc. The 415 * string is a path along hub ports, from the root. Each device's 416 * dev->devpath will be stable until USB is re-cabled, and hubs 417 * are often labeled with these port numbers. The bus_id isn't 418 * as stable: bus->busnum changes easily from modprobe order, 419 * cardbus or pci hotplugging, and so on. 420 */ 421 if (unlikely (!parent)) { 422 dev->devpath [0] = '0'; 423 424 dev->dev.parent = bus->controller; 425 sprintf (&dev->dev.bus_id[0], "usb%d", bus->busnum); 426 } else { 427 /* match any labeling on the hubs; it's one-based */ 428 if (parent->devpath [0] == '0') 429 snprintf (dev->devpath, sizeof dev->devpath, 430 "%d", port1); 431 else 432 snprintf (dev->devpath, sizeof dev->devpath, 433 "%s.%d", parent->devpath, port1); 434 435 dev->dev.parent = &parent->dev; 436 sprintf (&dev->dev.bus_id[0], "%d-%s", 437 bus->busnum, dev->devpath); 438 439 /* hub driver sets up TT records */ 440 } 441 442 dev->portnum = port1; 443 dev->bus = bus; 444 dev->parent = parent; 445 INIT_LIST_HEAD(&dev->filelist); 446 447 return dev; 448} 449 450/** 451 * usb_get_dev - increments the reference count of the usb device structure 452 * @dev: the device being referenced 453 * 454 * Each live reference to a device should be refcounted. 455 * 456 * Drivers for USB interfaces should normally record such references in 457 * their probe() methods, when they bind to an interface, and release 458 * them by calling usb_put_dev(), in their disconnect() methods. 459 * 460 * A pointer to the device with the incremented reference counter is returned. 461 */ 462struct usb_device *usb_get_dev(struct usb_device *dev) 463{ 464 if (dev) 465 get_device(&dev->dev); 466 return dev; 467} 468 469/** 470 * usb_put_dev - release a use of the usb device structure 471 * @dev: device that's been disconnected 472 * 473 * Must be called when a user of a device is finished with it. When the last 474 * user of the device calls this function, the memory of the device is freed. 475 */ 476void usb_put_dev(struct usb_device *dev) 477{ 478 if (dev) 479 put_device(&dev->dev); 480} 481 482/** 483 * usb_get_intf - increments the reference count of the usb interface structure 484 * @intf: the interface being referenced 485 * 486 * Each live reference to a interface must be refcounted. 487 * 488 * Drivers for USB interfaces should normally record such references in 489 * their probe() methods, when they bind to an interface, and release 490 * them by calling usb_put_intf(), in their disconnect() methods. 491 * 492 * A pointer to the interface with the incremented reference counter is 493 * returned. 494 */ 495struct usb_interface *usb_get_intf(struct usb_interface *intf) 496{ 497 if (intf) 498 get_device(&intf->dev); 499 return intf; 500} 501 502/** 503 * usb_put_intf - release a use of the usb interface structure 504 * @intf: interface that's been decremented 505 * 506 * Must be called when a user of an interface is finished with it. When the 507 * last user of the interface calls this function, the memory of the interface 508 * is freed. 509 */ 510void usb_put_intf(struct usb_interface *intf) 511{ 512 if (intf) 513 put_device(&intf->dev); 514} 515 516 517/* USB device locking 518 * 519 * USB devices and interfaces are locked using the semaphore in their 520 * embedded struct device. The hub driver guarantees that whenever a 521 * device is connected or disconnected, drivers are called with the 522 * USB device locked as well as their particular interface. 523 * 524 * Complications arise when several devices are to be locked at the same 525 * time. Only hub-aware drivers that are part of usbcore ever have to 526 * do this; nobody else needs to worry about it. The rule for locking 527 * is simple: 528 * 529 * When locking both a device and its parent, always lock the 530 * the parent first. 531 */ 532 533/** 534 * usb_lock_device_for_reset - cautiously acquire the lock for a 535 * usb device structure 536 * @udev: device that's being locked 537 * @iface: interface bound to the driver making the request (optional) 538 * 539 * Attempts to acquire the device lock, but fails if the device is 540 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface 541 * is neither BINDING nor BOUND. Rather than sleeping to wait for the 542 * lock, the routine polls repeatedly. This is to prevent deadlock with 543 * disconnect; in some drivers (such as usb-storage) the disconnect() 544 * or suspend() method will block waiting for a device reset to complete. 545 * 546 * Returns a negative error code for failure, otherwise 1 or 0 to indicate 547 * that the device will or will not have to be unlocked. (0 can be 548 * returned when an interface is given and is BINDING, because in that 549 * case the driver already owns the device lock.) 550 */ 551int usb_lock_device_for_reset(struct usb_device *udev, 552 struct usb_interface *iface) 553{ 554 unsigned long jiffies_expire = jiffies + HZ; 555 556 if (udev->state == USB_STATE_NOTATTACHED) 557 return -ENODEV; 558 if (udev->state == USB_STATE_SUSPENDED) 559 return -EHOSTUNREACH; 560 if (iface) { 561 switch (iface->condition) { 562 case USB_INTERFACE_BINDING: 563 return 0; 564 case USB_INTERFACE_BOUND: 565 break; 566 default: 567 return -EINTR; 568 } 569 } 570 571 while (usb_trylock_device(udev) != 0) { 572 573 /* If we can't acquire the lock after waiting one second, 574 * we're probably deadlocked */ 575 if (time_after(jiffies, jiffies_expire)) 576 return -EBUSY; 577 578 msleep(15); 579 if (udev->state == USB_STATE_NOTATTACHED) 580 return -ENODEV; 581 if (udev->state == USB_STATE_SUSPENDED) 582 return -EHOSTUNREACH; 583 if (iface && iface->condition != USB_INTERFACE_BOUND) 584 return -EINTR; 585 } 586 return 1; 587} 588 589 590static struct usb_device *match_device(struct usb_device *dev, 591 u16 vendor_id, u16 product_id) 592{ 593 struct usb_device *ret_dev = NULL; 594 int child; 595 596 dev_dbg(&dev->dev, "check for vendor %04x, product %04x ...\n", 597 le16_to_cpu(dev->descriptor.idVendor), 598 le16_to_cpu(dev->descriptor.idProduct)); 599 600 /* see if this device matches */ 601 if ((vendor_id == le16_to_cpu(dev->descriptor.idVendor)) && 602 (product_id == le16_to_cpu(dev->descriptor.idProduct))) { 603 dev_dbg (&dev->dev, "matched this device!\n"); 604 ret_dev = usb_get_dev(dev); 605 goto exit; 606 } 607 608 /* look through all of the children of this device */ 609 for (child = 0; child < dev->maxchild; ++child) { 610 if (dev->children[child]) { 611 usb_lock_device(dev->children[child]); 612 ret_dev = match_device(dev->children[child], 613 vendor_id, product_id); 614 usb_unlock_device(dev->children[child]); 615 if (ret_dev) 616 goto exit; 617 } 618 } 619exit: 620 return ret_dev; 621} 622 623/** 624 * usb_find_device - find a specific usb device in the system 625 * @vendor_id: the vendor id of the device to find 626 * @product_id: the product id of the device to find 627 * 628 * Returns a pointer to a struct usb_device if such a specified usb 629 * device is present in the system currently. The usage count of the 630 * device will be incremented if a device is found. Make sure to call 631 * usb_put_dev() when the caller is finished with the device. 632 * 633 * If a device with the specified vendor and product id is not found, 634 * NULL is returned. 635 */ 636struct usb_device *usb_find_device(u16 vendor_id, u16 product_id) 637{ 638 struct list_head *buslist; 639 struct usb_bus *bus; 640 struct usb_device *dev = NULL; 641 642 mutex_lock(&usb_bus_list_lock); 643 for (buslist = usb_bus_list.next; 644 buslist != &usb_bus_list; 645 buslist = buslist->next) { 646 bus = container_of(buslist, struct usb_bus, bus_list); 647 if (!bus->root_hub) 648 continue; 649 usb_lock_device(bus->root_hub); 650 dev = match_device(bus->root_hub, vendor_id, product_id); 651 usb_unlock_device(bus->root_hub); 652 if (dev) 653 goto exit; 654 } 655exit: 656 mutex_unlock(&usb_bus_list_lock); 657 return dev; 658} 659 660/** 661 * usb_get_current_frame_number - return current bus frame number 662 * @dev: the device whose bus is being queried 663 * 664 * Returns the current frame number for the USB host controller 665 * used with the given USB device. This can be used when scheduling 666 * isochronous requests. 667 * 668 * Note that different kinds of host controller have different 669 * "scheduling horizons". While one type might support scheduling only 670 * 32 frames into the future, others could support scheduling up to 671 * 1024 frames into the future. 672 */ 673int usb_get_current_frame_number(struct usb_device *dev) 674{ 675 return dev->bus->op->get_frame_number (dev); 676} 677 678/*-------------------------------------------------------------------*/ 679/* 680 * __usb_get_extra_descriptor() finds a descriptor of specific type in the 681 * extra field of the interface and endpoint descriptor structs. 682 */ 683 684int __usb_get_extra_descriptor(char *buffer, unsigned size, 685 unsigned char type, void **ptr) 686{ 687 struct usb_descriptor_header *header; 688 689 while (size >= sizeof(struct usb_descriptor_header)) { 690 header = (struct usb_descriptor_header *)buffer; 691 692 if (header->bLength < 2) { 693 printk(KERN_ERR 694 "%s: bogus descriptor, type %d length %d\n", 695 usbcore_name, 696 header->bDescriptorType, 697 header->bLength); 698 return -1; 699 } 700 701 if (header->bDescriptorType == type) { 702 *ptr = header; 703 return 0; 704 } 705 706 buffer += header->bLength; 707 size -= header->bLength; 708 } 709 return -1; 710} 711 712/** 713 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP 714 * @dev: device the buffer will be used with 715 * @size: requested buffer size 716 * @mem_flags: affect whether allocation may block 717 * @dma: used to return DMA address of buffer 718 * 719 * Return value is either null (indicating no buffer could be allocated), or 720 * the cpu-space pointer to a buffer that may be used to perform DMA to the 721 * specified device. Such cpu-space buffers are returned along with the DMA 722 * address (through the pointer provided). 723 * 724 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags 725 * to avoid behaviors like using "DMA bounce buffers", or tying down I/O 726 * mapping hardware for long idle periods. The implementation varies between 727 * platforms, depending on details of how DMA will work to this device. 728 * Using these buffers also helps prevent cacheline sharing problems on 729 * architectures where CPU caches are not DMA-coherent. 730 * 731 * When the buffer is no longer used, free it with usb_buffer_free(). 732 */ 733void *usb_buffer_alloc ( 734 struct usb_device *dev, 735 size_t size, 736 gfp_t mem_flags, 737 dma_addr_t *dma 738) 739{ 740 if (!dev || !dev->bus || !dev->bus->op || !dev->bus->op->buffer_alloc) 741 return NULL; 742 return dev->bus->op->buffer_alloc (dev->bus, size, mem_flags, dma); 743} 744 745/** 746 * usb_buffer_free - free memory allocated with usb_buffer_alloc() 747 * @dev: device the buffer was used with 748 * @size: requested buffer size 749 * @addr: CPU address of buffer 750 * @dma: DMA address of buffer 751 * 752 * This reclaims an I/O buffer, letting it be reused. The memory must have 753 * been allocated using usb_buffer_alloc(), and the parameters must match 754 * those provided in that allocation request. 755 */ 756void usb_buffer_free ( 757 struct usb_device *dev, 758 size_t size, 759 void *addr, 760 dma_addr_t dma 761) 762{ 763 if (!dev || !dev->bus || !dev->bus->op || !dev->bus->op->buffer_free) 764 return; 765 if (!addr) 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 if (dev->driver == NULL) 996 return 0; 997 return (dev->power.power_state.event == PM_EVENT_ON) ? -EBUSY : 0; 998} 999 1000static int usb_generic_suspend(struct device *dev, pm_message_t message) 1001{ 1002 struct usb_interface *intf; 1003 struct usb_driver *driver; 1004 int status; 1005 1006 /* USB devices enter SUSPEND state through their hubs, but can be 1007 * marked for FREEZE as soon as their children are already idled. 1008 * But those semantics are useless, so we equate the two (sigh). 1009 */ 1010 if (dev->driver == &usb_generic_driver) { 1011 if (dev->power.power_state.event == message.event) 1012 return 0; 1013 /* we need to rule out bogus requests through sysfs */ 1014 status = device_for_each_child(dev, NULL, verify_suspended); 1015 if (status) 1016 return status; 1017 return usb_port_suspend(to_usb_device(dev)); 1018 } 1019 1020 if ((dev->driver == NULL) || 1021 (dev->driver_data == &usb_generic_driver_data)) 1022 return 0; 1023 1024 intf = to_usb_interface(dev); 1025 driver = to_usb_driver(dev->driver); 1026 1027 /* with no hardware, USB interfaces only use FREEZE and ON states */ 1028 if (!is_active(intf)) 1029 return 0; 1030 1031 if (driver->suspend && driver->resume) { 1032 status = driver->suspend(intf, message); 1033 if (status) 1034 dev_err(dev, "%s error %d\n", "suspend", status); 1035 else 1036 mark_quiesced(intf); 1037 } else { 1038 // FIXME else if there's no suspend method, disconnect... 1039 dev_warn(dev, "no suspend for driver %s?\n", driver->name); 1040 mark_quiesced(intf); 1041 status = 0; 1042 } 1043 return status; 1044} 1045 1046static int usb_generic_resume(struct device *dev) 1047{ 1048 struct usb_interface *intf; 1049 struct usb_driver *driver; 1050 struct usb_device *udev; 1051 int status; 1052 1053 if (dev->power.power_state.event == PM_EVENT_ON) 1054 return 0; 1055 1056 /* mark things as "on" immediately, no matter what errors crop up */ 1057 dev->power.power_state.event = PM_EVENT_ON; 1058 1059 /* devices resume through their hubs */ 1060 if (dev->driver == &usb_generic_driver) { 1061 udev = to_usb_device(dev); 1062 if (udev->state == USB_STATE_NOTATTACHED) 1063 return 0; 1064 return usb_port_resume(udev); 1065 } 1066 1067 if ((dev->driver == NULL) || 1068 (dev->driver_data == &usb_generic_driver_data)) { 1069 dev->power.power_state.event = PM_EVENT_FREEZE; 1070 return 0; 1071 } 1072 1073 intf = to_usb_interface(dev); 1074 driver = to_usb_driver(dev->driver); 1075 1076 udev = interface_to_usbdev(intf); 1077 if (udev->state == USB_STATE_NOTATTACHED) 1078 return 0; 1079 1080 /* if driver was suspended, it has a resume method; 1081 * however, sysfs can wrongly mark things as suspended 1082 * (on the "no suspend method" FIXME path above) 1083 */ 1084 if (driver->resume) { 1085 status = driver->resume(intf); 1086 if (status) { 1087 dev_err(dev, "%s error %d\n", "resume", status); 1088 mark_quiesced(intf); 1089 } 1090 } else 1091 dev_warn(dev, "no resume for driver %s?\n", driver->name); 1092 return 0; 1093} 1094 1095struct bus_type usb_bus_type = { 1096 .name = "usb", 1097 .match = usb_device_match, 1098 .uevent = usb_uevent, 1099 .suspend = usb_generic_suspend, 1100 .resume = usb_generic_resume, 1101}; 1102 1103/* format to disable USB on kernel command line is: nousb */ 1104__module_param_call("", nousb, param_set_bool, param_get_bool, &nousb, 0444); 1105 1106/* 1107 * for external read access to <nousb> 1108 */ 1109int usb_disabled(void) 1110{ 1111 return nousb; 1112} 1113 1114/* 1115 * Init 1116 */ 1117static int __init usb_init(void) 1118{ 1119 int retval; 1120 if (nousb) { 1121 pr_info ("%s: USB support disabled\n", usbcore_name); 1122 return 0; 1123 } 1124 1125 retval = bus_register(&usb_bus_type); 1126 if (retval) 1127 goto out; 1128 retval = usb_host_init(); 1129 if (retval) 1130 goto host_init_failed; 1131 retval = usb_major_init(); 1132 if (retval) 1133 goto major_init_failed; 1134 retval = usb_register(&usbfs_driver); 1135 if (retval) 1136 goto driver_register_failed; 1137 retval = usbdev_init(); 1138 if (retval) 1139 goto usbdevice_init_failed; 1140 retval = usbfs_init(); 1141 if (retval) 1142 goto fs_init_failed; 1143 retval = usb_hub_init(); 1144 if (retval) 1145 goto hub_init_failed; 1146 retval = driver_register(&usb_generic_driver); 1147 if (!retval) 1148 goto out; 1149 1150 usb_hub_cleanup(); 1151hub_init_failed: 1152 usbfs_cleanup(); 1153fs_init_failed: 1154 usbdev_cleanup(); 1155usbdevice_init_failed: 1156 usb_deregister(&usbfs_driver); 1157driver_register_failed: 1158 usb_major_cleanup(); 1159major_init_failed: 1160 usb_host_cleanup(); 1161host_init_failed: 1162 bus_unregister(&usb_bus_type); 1163out: 1164 return retval; 1165} 1166 1167/* 1168 * Cleanup 1169 */ 1170static void __exit usb_exit(void) 1171{ 1172 /* This will matter if shutdown/reboot does exitcalls. */ 1173 if (nousb) 1174 return; 1175 1176 driver_unregister(&usb_generic_driver); 1177 usb_major_cleanup(); 1178 usbfs_cleanup(); 1179 usb_deregister(&usbfs_driver); 1180 usbdev_cleanup(); 1181 usb_hub_cleanup(); 1182 usb_host_cleanup(); 1183 bus_unregister(&usb_bus_type); 1184} 1185 1186subsys_initcall(usb_init); 1187module_exit(usb_exit); 1188 1189/* 1190 * USB may be built into the kernel or be built as modules. 1191 * These symbols are exported for device (or host controller) 1192 * driver modules to use. 1193 */ 1194 1195EXPORT_SYMBOL(usb_disabled); 1196 1197EXPORT_SYMBOL_GPL(usb_get_intf); 1198EXPORT_SYMBOL_GPL(usb_put_intf); 1199 1200EXPORT_SYMBOL(usb_put_dev); 1201EXPORT_SYMBOL(usb_get_dev); 1202EXPORT_SYMBOL(usb_hub_tt_clear_buffer); 1203 1204EXPORT_SYMBOL(usb_lock_device_for_reset); 1205 1206EXPORT_SYMBOL(usb_driver_claim_interface); 1207EXPORT_SYMBOL(usb_driver_release_interface); 1208EXPORT_SYMBOL(usb_find_interface); 1209EXPORT_SYMBOL(usb_ifnum_to_if); 1210EXPORT_SYMBOL(usb_altnum_to_altsetting); 1211 1212EXPORT_SYMBOL(__usb_get_extra_descriptor); 1213 1214EXPORT_SYMBOL(usb_find_device); 1215EXPORT_SYMBOL(usb_get_current_frame_number); 1216 1217EXPORT_SYMBOL (usb_buffer_alloc); 1218EXPORT_SYMBOL (usb_buffer_free); 1219 1220#if 0 1221EXPORT_SYMBOL (usb_buffer_map); 1222EXPORT_SYMBOL (usb_buffer_dmasync); 1223EXPORT_SYMBOL (usb_buffer_unmap); 1224#endif 1225 1226EXPORT_SYMBOL (usb_buffer_map_sg); 1227#if 0 1228EXPORT_SYMBOL (usb_buffer_dmasync_sg); 1229#endif 1230EXPORT_SYMBOL (usb_buffer_unmap_sg); 1231 1232MODULE_LICENSE("GPL"); 1233