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/include/linux/usb.h

https://github.com/mstsirkin/kvm
C Header | 1217 lines | 454 code | 124 blank | 639 comment | 2 complexity | 89a9edc9b43526f84ca8c91184de710b MD5 | raw file
  1. #ifndef __LINUX_USB_H
  2. #define __LINUX_USB_H
  3. #include <linux/mod_devicetable.h>
  4. #include <linux/usb/ch9.h>
  5. #define USB_MAJOR 180
  6. #define USB_DEVICE_MAJOR 189
  7. #ifdef __KERNEL__
  8. #include <linux/errno.h> /* for -ENODEV */
  9. #include <linux/delay.h> /* for mdelay() */
  10. #include <linux/interrupt.h> /* for in_interrupt() */
  11. #include <linux/list.h> /* for struct list_head */
  12. #include <linux/kref.h> /* for struct kref */
  13. #include <linux/device.h> /* for struct device */
  14. #include <linux/fs.h> /* for struct file_operations */
  15. #include <linux/completion.h> /* for struct completion */
  16. #include <linux/sched.h> /* for current && schedule_timeout */
  17. #include <linux/mutex.h> /* for struct mutex */
  18. #include <linux/pm_runtime.h> /* for runtime PM */
  19. struct usb_device;
  20. struct usb_driver;
  21. struct wusb_dev;
  22. /*-------------------------------------------------------------------------*/
  23. /*
  24. * Host-side wrappers for standard USB descriptors ... these are parsed
  25. * from the data provided by devices. Parsing turns them from a flat
  26. * sequence of descriptors into a hierarchy:
  27. *
  28. * - devices have one (usually) or more configs;
  29. * - configs have one (often) or more interfaces;
  30. * - interfaces have one (usually) or more settings;
  31. * - each interface setting has zero or (usually) more endpoints.
  32. * - a SuperSpeed endpoint has a companion descriptor
  33. *
  34. * And there might be other descriptors mixed in with those.
  35. *
  36. * Devices may also have class-specific or vendor-specific descriptors.
  37. */
  38. struct ep_device;
  39. /**
  40. * struct usb_host_endpoint - host-side endpoint descriptor and queue
  41. * @desc: descriptor for this endpoint, wMaxPacketSize in native byteorder
  42. * @ss_ep_comp: SuperSpeed companion descriptor for this endpoint
  43. * @urb_list: urbs queued to this endpoint; maintained by usbcore
  44. * @hcpriv: for use by HCD; typically holds hardware dma queue head (QH)
  45. * with one or more transfer descriptors (TDs) per urb
  46. * @ep_dev: ep_device for sysfs info
  47. * @extra: descriptors following this endpoint in the configuration
  48. * @extralen: how many bytes of "extra" are valid
  49. * @enabled: URBs may be submitted to this endpoint
  50. *
  51. * USB requests are always queued to a given endpoint, identified by a
  52. * descriptor within an active interface in a given USB configuration.
  53. */
  54. struct usb_host_endpoint {
  55. struct usb_endpoint_descriptor desc;
  56. struct usb_ss_ep_comp_descriptor ss_ep_comp;
  57. struct list_head urb_list;
  58. void *hcpriv;
  59. struct ep_device *ep_dev; /* For sysfs info */
  60. unsigned char *extra; /* Extra descriptors */
  61. int extralen;
  62. int enabled;
  63. };
  64. /* host-side wrapper for one interface setting's parsed descriptors */
  65. struct usb_host_interface {
  66. struct usb_interface_descriptor desc;
  67. /* array of desc.bNumEndpoint endpoints associated with this
  68. * interface setting. these will be in no particular order.
  69. */
  70. struct usb_host_endpoint *endpoint;
  71. char *string; /* iInterface string, if present */
  72. unsigned char *extra; /* Extra descriptors */
  73. int extralen;
  74. };
  75. enum usb_interface_condition {
  76. USB_INTERFACE_UNBOUND = 0,
  77. USB_INTERFACE_BINDING,
  78. USB_INTERFACE_BOUND,
  79. USB_INTERFACE_UNBINDING,
  80. };
  81. /**
  82. * struct usb_interface - what usb device drivers talk to
  83. * @altsetting: array of interface structures, one for each alternate
  84. * setting that may be selected. Each one includes a set of
  85. * endpoint configurations. They will be in no particular order.
  86. * @cur_altsetting: the current altsetting.
  87. * @num_altsetting: number of altsettings defined.
  88. * @intf_assoc: interface association descriptor
  89. * @minor: the minor number assigned to this interface, if this
  90. * interface is bound to a driver that uses the USB major number.
  91. * If this interface does not use the USB major, this field should
  92. * be unused. The driver should set this value in the probe()
  93. * function of the driver, after it has been assigned a minor
  94. * number from the USB core by calling usb_register_dev().
  95. * @condition: binding state of the interface: not bound, binding
  96. * (in probe()), bound to a driver, or unbinding (in disconnect())
  97. * @sysfs_files_created: sysfs attributes exist
  98. * @ep_devs_created: endpoint child pseudo-devices exist
  99. * @unregistering: flag set when the interface is being unregistered
  100. * @needs_remote_wakeup: flag set when the driver requires remote-wakeup
  101. * capability during autosuspend.
  102. * @needs_altsetting0: flag set when a set-interface request for altsetting 0
  103. * has been deferred.
  104. * @needs_binding: flag set when the driver should be re-probed or unbound
  105. * following a reset or suspend operation it doesn't support.
  106. * @dev: driver model's view of this device
  107. * @usb_dev: if an interface is bound to the USB major, this will point
  108. * to the sysfs representation for that device.
  109. * @pm_usage_cnt: PM usage counter for this interface
  110. * @reset_ws: Used for scheduling resets from atomic context.
  111. * @reset_running: set to 1 if the interface is currently running a
  112. * queued reset so that usb_cancel_queued_reset() doesn't try to
  113. * remove from the workqueue when running inside the worker
  114. * thread. See __usb_queue_reset_device().
  115. * @resetting_device: USB core reset the device, so use alt setting 0 as
  116. * current; needs bandwidth alloc after reset.
  117. *
  118. * USB device drivers attach to interfaces on a physical device. Each
  119. * interface encapsulates a single high level function, such as feeding
  120. * an audio stream to a speaker or reporting a change in a volume control.
  121. * Many USB devices only have one interface. The protocol used to talk to
  122. * an interface's endpoints can be defined in a usb "class" specification,
  123. * or by a product's vendor. The (default) control endpoint is part of
  124. * every interface, but is never listed among the interface's descriptors.
  125. *
  126. * The driver that is bound to the interface can use standard driver model
  127. * calls such as dev_get_drvdata() on the dev member of this structure.
  128. *
  129. * Each interface may have alternate settings. The initial configuration
  130. * of a device sets altsetting 0, but the device driver can change
  131. * that setting using usb_set_interface(). Alternate settings are often
  132. * used to control the use of periodic endpoints, such as by having
  133. * different endpoints use different amounts of reserved USB bandwidth.
  134. * All standards-conformant USB devices that use isochronous endpoints
  135. * will use them in non-default settings.
  136. *
  137. * The USB specification says that alternate setting numbers must run from
  138. * 0 to one less than the total number of alternate settings. But some
  139. * devices manage to mess this up, and the structures aren't necessarily
  140. * stored in numerical order anyhow. Use usb_altnum_to_altsetting() to
  141. * look up an alternate setting in the altsetting array based on its number.
  142. */
  143. struct usb_interface {
  144. /* array of alternate settings for this interface,
  145. * stored in no particular order */
  146. struct usb_host_interface *altsetting;
  147. struct usb_host_interface *cur_altsetting; /* the currently
  148. * active alternate setting */
  149. unsigned num_altsetting; /* number of alternate settings */
  150. /* If there is an interface association descriptor then it will list
  151. * the associated interfaces */
  152. struct usb_interface_assoc_descriptor *intf_assoc;
  153. int minor; /* minor number this interface is
  154. * bound to */
  155. enum usb_interface_condition condition; /* state of binding */
  156. unsigned sysfs_files_created:1; /* the sysfs attributes exist */
  157. unsigned ep_devs_created:1; /* endpoint "devices" exist */
  158. unsigned unregistering:1; /* unregistration is in progress */
  159. unsigned needs_remote_wakeup:1; /* driver requires remote wakeup */
  160. unsigned needs_altsetting0:1; /* switch to altsetting 0 is pending */
  161. unsigned needs_binding:1; /* needs delayed unbind/rebind */
  162. unsigned reset_running:1;
  163. unsigned resetting_device:1; /* true: bandwidth alloc after reset */
  164. struct device dev; /* interface specific device info */
  165. struct device *usb_dev;
  166. atomic_t pm_usage_cnt; /* usage counter for autosuspend */
  167. struct work_struct reset_ws; /* for resets in atomic context */
  168. };
  169. #define to_usb_interface(d) container_of(d, struct usb_interface, dev)
  170. static inline void *usb_get_intfdata(struct usb_interface *intf)
  171. {
  172. return dev_get_drvdata(&intf->dev);
  173. }
  174. static inline void usb_set_intfdata(struct usb_interface *intf, void *data)
  175. {
  176. dev_set_drvdata(&intf->dev, data);
  177. }
  178. struct usb_interface *usb_get_intf(struct usb_interface *intf);
  179. void usb_put_intf(struct usb_interface *intf);
  180. /* this maximum is arbitrary */
  181. #define USB_MAXINTERFACES 32
  182. #define USB_MAXIADS (USB_MAXINTERFACES/2)
  183. /**
  184. * struct usb_interface_cache - long-term representation of a device interface
  185. * @num_altsetting: number of altsettings defined.
  186. * @ref: reference counter.
  187. * @altsetting: variable-length array of interface structures, one for
  188. * each alternate setting that may be selected. Each one includes a
  189. * set of endpoint configurations. They will be in no particular order.
  190. *
  191. * These structures persist for the lifetime of a usb_device, unlike
  192. * struct usb_interface (which persists only as long as its configuration
  193. * is installed). The altsetting arrays can be accessed through these
  194. * structures at any time, permitting comparison of configurations and
  195. * providing support for the /proc/bus/usb/devices pseudo-file.
  196. */
  197. struct usb_interface_cache {
  198. unsigned num_altsetting; /* number of alternate settings */
  199. struct kref ref; /* reference counter */
  200. /* variable-length array of alternate settings for this interface,
  201. * stored in no particular order */
  202. struct usb_host_interface altsetting[0];
  203. };
  204. #define ref_to_usb_interface_cache(r) \
  205. container_of(r, struct usb_interface_cache, ref)
  206. #define altsetting_to_usb_interface_cache(a) \
  207. container_of(a, struct usb_interface_cache, altsetting[0])
  208. /**
  209. * struct usb_host_config - representation of a device's configuration
  210. * @desc: the device's configuration descriptor.
  211. * @string: pointer to the cached version of the iConfiguration string, if
  212. * present for this configuration.
  213. * @intf_assoc: list of any interface association descriptors in this config
  214. * @interface: array of pointers to usb_interface structures, one for each
  215. * interface in the configuration. The number of interfaces is stored
  216. * in desc.bNumInterfaces. These pointers are valid only while the
  217. * the configuration is active.
  218. * @intf_cache: array of pointers to usb_interface_cache structures, one
  219. * for each interface in the configuration. These structures exist
  220. * for the entire life of the device.
  221. * @extra: pointer to buffer containing all extra descriptors associated
  222. * with this configuration (those preceding the first interface
  223. * descriptor).
  224. * @extralen: length of the extra descriptors buffer.
  225. *
  226. * USB devices may have multiple configurations, but only one can be active
  227. * at any time. Each encapsulates a different operational environment;
  228. * for example, a dual-speed device would have separate configurations for
  229. * full-speed and high-speed operation. The number of configurations
  230. * available is stored in the device descriptor as bNumConfigurations.
  231. *
  232. * A configuration can contain multiple interfaces. Each corresponds to
  233. * a different function of the USB device, and all are available whenever
  234. * the configuration is active. The USB standard says that interfaces
  235. * are supposed to be numbered from 0 to desc.bNumInterfaces-1, but a lot
  236. * of devices get this wrong. In addition, the interface array is not
  237. * guaranteed to be sorted in numerical order. Use usb_ifnum_to_if() to
  238. * look up an interface entry based on its number.
  239. *
  240. * Device drivers should not attempt to activate configurations. The choice
  241. * of which configuration to install is a policy decision based on such
  242. * considerations as available power, functionality provided, and the user's
  243. * desires (expressed through userspace tools). However, drivers can call
  244. * usb_reset_configuration() to reinitialize the current configuration and
  245. * all its interfaces.
  246. */
  247. struct usb_host_config {
  248. struct usb_config_descriptor desc;
  249. char *string; /* iConfiguration string, if present */
  250. /* List of any Interface Association Descriptors in this
  251. * configuration. */
  252. struct usb_interface_assoc_descriptor *intf_assoc[USB_MAXIADS];
  253. /* the interfaces associated with this configuration,
  254. * stored in no particular order */
  255. struct usb_interface *interface[USB_MAXINTERFACES];
  256. /* Interface information available even when this is not the
  257. * active configuration */
  258. struct usb_interface_cache *intf_cache[USB_MAXINTERFACES];
  259. unsigned char *extra; /* Extra descriptors */
  260. int extralen;
  261. };
  262. int __usb_get_extra_descriptor(char *buffer, unsigned size,
  263. unsigned char type, void **ptr);
  264. #define usb_get_extra_descriptor(ifpoint, type, ptr) \
  265. __usb_get_extra_descriptor((ifpoint)->extra, \
  266. (ifpoint)->extralen, \
  267. type, (void **)ptr)
  268. /* ----------------------------------------------------------------------- */
  269. /* USB device number allocation bitmap */
  270. struct usb_devmap {
  271. unsigned long devicemap[128 / (8*sizeof(unsigned long))];
  272. };
  273. /*
  274. * Allocated per bus (tree of devices) we have:
  275. */
  276. struct usb_bus {
  277. struct device *controller; /* host/master side hardware */
  278. int busnum; /* Bus number (in order of reg) */
  279. const char *bus_name; /* stable id (PCI slot_name etc) */
  280. u8 uses_dma; /* Does the host controller use DMA? */
  281. u8 uses_pio_for_control; /*
  282. * Does the host controller use PIO
  283. * for control transfers?
  284. */
  285. u8 otg_port; /* 0, or number of OTG/HNP port */
  286. unsigned is_b_host:1; /* true during some HNP roleswitches */
  287. unsigned b_hnp_enable:1; /* OTG: did A-Host enable HNP? */
  288. unsigned sg_tablesize; /* 0 or largest number of sg list entries */
  289. int devnum_next; /* Next open device number in
  290. * round-robin allocation */
  291. struct usb_devmap devmap; /* device address allocation map */
  292. struct usb_device *root_hub; /* Root hub */
  293. struct usb_bus *hs_companion; /* Companion EHCI bus, if any */
  294. struct list_head bus_list; /* list of busses */
  295. int bandwidth_allocated; /* on this bus: how much of the time
  296. * reserved for periodic (intr/iso)
  297. * requests is used, on average?
  298. * Units: microseconds/frame.
  299. * Limits: Full/low speed reserve 90%,
  300. * while high speed reserves 80%.
  301. */
  302. int bandwidth_int_reqs; /* number of Interrupt requests */
  303. int bandwidth_isoc_reqs; /* number of Isoc. requests */
  304. #ifdef CONFIG_USB_DEVICEFS
  305. struct dentry *usbfs_dentry; /* usbfs dentry entry for the bus */
  306. #endif
  307. #if defined(CONFIG_USB_MON) || defined(CONFIG_USB_MON_MODULE)
  308. struct mon_bus *mon_bus; /* non-null when associated */
  309. int monitored; /* non-zero when monitored */
  310. #endif
  311. };
  312. /* ----------------------------------------------------------------------- */
  313. /* This is arbitrary.
  314. * From USB 2.0 spec Table 11-13, offset 7, a hub can
  315. * have up to 255 ports. The most yet reported is 10.
  316. *
  317. * Current Wireless USB host hardware (Intel i1480 for example) allows
  318. * up to 22 devices to connect. Upcoming hardware might raise that
  319. * limit. Because the arrays need to add a bit for hub status data, we
  320. * do 31, so plus one evens out to four bytes.
  321. */
  322. #define USB_MAXCHILDREN (31)
  323. struct usb_tt;
  324. /**
  325. * struct usb_device - kernel's representation of a USB device
  326. * @devnum: device number; address on a USB bus
  327. * @devpath: device ID string for use in messages (e.g., /port/...)
  328. * @route: tree topology hex string for use with xHCI
  329. * @state: device state: configured, not attached, etc.
  330. * @speed: device speed: high/full/low (or error)
  331. * @tt: Transaction Translator info; used with low/full speed dev, highspeed hub
  332. * @ttport: device port on that tt hub
  333. * @toggle: one bit for each endpoint, with ([0] = IN, [1] = OUT) endpoints
  334. * @parent: our hub, unless we're the root
  335. * @bus: bus we're part of
  336. * @ep0: endpoint 0 data (default control pipe)
  337. * @dev: generic device interface
  338. * @descriptor: USB device descriptor
  339. * @config: all of the device's configs
  340. * @actconfig: the active configuration
  341. * @ep_in: array of IN endpoints
  342. * @ep_out: array of OUT endpoints
  343. * @rawdescriptors: raw descriptors for each config
  344. * @bus_mA: Current available from the bus
  345. * @portnum: parent port number (origin 1)
  346. * @level: number of USB hub ancestors
  347. * @can_submit: URBs may be submitted
  348. * @persist_enabled: USB_PERSIST enabled for this device
  349. * @have_langid: whether string_langid is valid
  350. * @authorized: policy has said we can use it;
  351. * (user space) policy determines if we authorize this device to be
  352. * used or not. By default, wired USB devices are authorized.
  353. * WUSB devices are not, until we authorize them from user space.
  354. * FIXME -- complete doc
  355. * @authenticated: Crypto authentication passed
  356. * @wusb: device is Wireless USB
  357. * @string_langid: language ID for strings
  358. * @product: iProduct string, if present (static)
  359. * @manufacturer: iManufacturer string, if present (static)
  360. * @serial: iSerialNumber string, if present (static)
  361. * @filelist: usbfs files that are open to this device
  362. * @usb_classdev: USB class device that was created for usbfs device
  363. * access from userspace
  364. * @usbfs_dentry: usbfs dentry entry for the device
  365. * @maxchild: number of ports if hub
  366. * @children: child devices - USB devices that are attached to this hub
  367. * @quirks: quirks of the whole device
  368. * @urbnum: number of URBs submitted for the whole device
  369. * @active_duration: total time device is not suspended
  370. * @connect_time: time device was first connected
  371. * @do_remote_wakeup: remote wakeup should be enabled
  372. * @reset_resume: needs reset instead of resume
  373. * @wusb_dev: if this is a Wireless USB device, link to the WUSB
  374. * specific data for the device.
  375. * @slot_id: Slot ID assigned by xHCI
  376. *
  377. * Notes:
  378. * Usbcore drivers should not set usbdev->state directly. Instead use
  379. * usb_set_device_state().
  380. */
  381. struct usb_device {
  382. int devnum;
  383. char devpath[16];
  384. u32 route;
  385. enum usb_device_state state;
  386. enum usb_device_speed speed;
  387. struct usb_tt *tt;
  388. int ttport;
  389. unsigned int toggle[2];
  390. struct usb_device *parent;
  391. struct usb_bus *bus;
  392. struct usb_host_endpoint ep0;
  393. struct device dev;
  394. struct usb_device_descriptor descriptor;
  395. struct usb_host_config *config;
  396. struct usb_host_config *actconfig;
  397. struct usb_host_endpoint *ep_in[16];
  398. struct usb_host_endpoint *ep_out[16];
  399. char **rawdescriptors;
  400. unsigned short bus_mA;
  401. u8 portnum;
  402. u8 level;
  403. unsigned can_submit:1;
  404. unsigned persist_enabled:1;
  405. unsigned have_langid:1;
  406. unsigned authorized:1;
  407. unsigned authenticated:1;
  408. unsigned wusb:1;
  409. int string_langid;
  410. /* static strings from the device */
  411. char *product;
  412. char *manufacturer;
  413. char *serial;
  414. struct list_head filelist;
  415. #ifdef CONFIG_USB_DEVICE_CLASS
  416. struct device *usb_classdev;
  417. #endif
  418. #ifdef CONFIG_USB_DEVICEFS
  419. struct dentry *usbfs_dentry;
  420. #endif
  421. int maxchild;
  422. struct usb_device *children[USB_MAXCHILDREN];
  423. u32 quirks;
  424. atomic_t urbnum;
  425. unsigned long active_duration;
  426. #ifdef CONFIG_PM
  427. unsigned long connect_time;
  428. unsigned do_remote_wakeup:1;
  429. unsigned reset_resume:1;
  430. #endif
  431. struct wusb_dev *wusb_dev;
  432. int slot_id;
  433. };
  434. #define to_usb_device(d) container_of(d, struct usb_device, dev)
  435. static inline struct usb_device *interface_to_usbdev(struct usb_interface *intf)
  436. {
  437. return to_usb_device(intf->dev.parent);
  438. }
  439. extern struct usb_device *usb_get_dev(struct usb_device *dev);
  440. extern void usb_put_dev(struct usb_device *dev);
  441. /* USB device locking */
  442. #define usb_lock_device(udev) device_lock(&(udev)->dev)
  443. #define usb_unlock_device(udev) device_unlock(&(udev)->dev)
  444. #define usb_trylock_device(udev) device_trylock(&(udev)->dev)
  445. extern int usb_lock_device_for_reset(struct usb_device *udev,
  446. const struct usb_interface *iface);
  447. /* USB port reset for device reinitialization */
  448. extern int usb_reset_device(struct usb_device *dev);
  449. extern void usb_queue_reset_device(struct usb_interface *dev);
  450. /* USB autosuspend and autoresume */
  451. #ifdef CONFIG_USB_SUSPEND
  452. extern void usb_enable_autosuspend(struct usb_device *udev);
  453. extern void usb_disable_autosuspend(struct usb_device *udev);
  454. extern int usb_autopm_get_interface(struct usb_interface *intf);
  455. extern void usb_autopm_put_interface(struct usb_interface *intf);
  456. extern int usb_autopm_get_interface_async(struct usb_interface *intf);
  457. extern void usb_autopm_put_interface_async(struct usb_interface *intf);
  458. extern void usb_autopm_get_interface_no_resume(struct usb_interface *intf);
  459. extern void usb_autopm_put_interface_no_suspend(struct usb_interface *intf);
  460. static inline void usb_mark_last_busy(struct usb_device *udev)
  461. {
  462. pm_runtime_mark_last_busy(&udev->dev);
  463. }
  464. #else
  465. static inline int usb_enable_autosuspend(struct usb_device *udev)
  466. { return 0; }
  467. static inline int usb_disable_autosuspend(struct usb_device *udev)
  468. { return 0; }
  469. static inline int usb_autopm_get_interface(struct usb_interface *intf)
  470. { return 0; }
  471. static inline int usb_autopm_get_interface_async(struct usb_interface *intf)
  472. { return 0; }
  473. static inline void usb_autopm_put_interface(struct usb_interface *intf)
  474. { }
  475. static inline void usb_autopm_put_interface_async(struct usb_interface *intf)
  476. { }
  477. static inline void usb_autopm_get_interface_no_resume(
  478. struct usb_interface *intf)
  479. { }
  480. static inline void usb_autopm_put_interface_no_suspend(
  481. struct usb_interface *intf)
  482. { }
  483. static inline void usb_mark_last_busy(struct usb_device *udev)
  484. { }
  485. #endif
  486. /*-------------------------------------------------------------------------*/
  487. /* for drivers using iso endpoints */
  488. extern int usb_get_current_frame_number(struct usb_device *usb_dev);
  489. /* Sets up a group of bulk endpoints to support multiple stream IDs. */
  490. extern int usb_alloc_streams(struct usb_interface *interface,
  491. struct usb_host_endpoint **eps, unsigned int num_eps,
  492. unsigned int num_streams, gfp_t mem_flags);
  493. /* Reverts a group of bulk endpoints back to not using stream IDs. */
  494. extern void usb_free_streams(struct usb_interface *interface,
  495. struct usb_host_endpoint **eps, unsigned int num_eps,
  496. gfp_t mem_flags);
  497. /* used these for multi-interface device registration */
  498. extern int usb_driver_claim_interface(struct usb_driver *driver,
  499. struct usb_interface *iface, void *priv);
  500. /**
  501. * usb_interface_claimed - returns true iff an interface is claimed
  502. * @iface: the interface being checked
  503. *
  504. * Returns true (nonzero) iff the interface is claimed, else false (zero).
  505. * Callers must own the driver model's usb bus readlock. So driver
  506. * probe() entries don't need extra locking, but other call contexts
  507. * may need to explicitly claim that lock.
  508. *
  509. */
  510. static inline int usb_interface_claimed(struct usb_interface *iface)
  511. {
  512. return (iface->dev.driver != NULL);
  513. }
  514. extern void usb_driver_release_interface(struct usb_driver *driver,
  515. struct usb_interface *iface);
  516. const struct usb_device_id *usb_match_id(struct usb_interface *interface,
  517. const struct usb_device_id *id);
  518. extern int usb_match_one_id(struct usb_interface *interface,
  519. const struct usb_device_id *id);
  520. extern struct usb_interface *usb_find_interface(struct usb_driver *drv,
  521. int minor);
  522. extern struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
  523. unsigned ifnum);
  524. extern struct usb_host_interface *usb_altnum_to_altsetting(
  525. const struct usb_interface *intf, unsigned int altnum);
  526. extern struct usb_host_interface *usb_find_alt_setting(
  527. struct usb_host_config *config,
  528. unsigned int iface_num,
  529. unsigned int alt_num);
  530. /**
  531. * usb_make_path - returns stable device path in the usb tree
  532. * @dev: the device whose path is being constructed
  533. * @buf: where to put the string
  534. * @size: how big is "buf"?
  535. *
  536. * Returns length of the string (> 0) or negative if size was too small.
  537. *
  538. * This identifier is intended to be "stable", reflecting physical paths in
  539. * hardware such as physical bus addresses for host controllers or ports on
  540. * USB hubs. That makes it stay the same until systems are physically
  541. * reconfigured, by re-cabling a tree of USB devices or by moving USB host
  542. * controllers. Adding and removing devices, including virtual root hubs
  543. * in host controller driver modules, does not change these path identifiers;
  544. * neither does rebooting or re-enumerating. These are more useful identifiers
  545. * than changeable ("unstable") ones like bus numbers or device addresses.
  546. *
  547. * With a partial exception for devices connected to USB 2.0 root hubs, these
  548. * identifiers are also predictable. So long as the device tree isn't changed,
  549. * plugging any USB device into a given hub port always gives it the same path.
  550. * Because of the use of "companion" controllers, devices connected to ports on
  551. * USB 2.0 root hubs (EHCI host controllers) will get one path ID if they are
  552. * high speed, and a different one if they are full or low speed.
  553. */
  554. static inline int usb_make_path(struct usb_device *dev, char *buf, size_t size)
  555. {
  556. int actual;
  557. actual = snprintf(buf, size, "usb-%s-%s", dev->bus->bus_name,
  558. dev->devpath);
  559. return (actual >= (int)size) ? -1 : actual;
  560. }
  561. /*-------------------------------------------------------------------------*/
  562. #define USB_DEVICE_ID_MATCH_DEVICE \
  563. (USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT)
  564. #define USB_DEVICE_ID_MATCH_DEV_RANGE \
  565. (USB_DEVICE_ID_MATCH_DEV_LO | USB_DEVICE_ID_MATCH_DEV_HI)
  566. #define USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION \
  567. (USB_DEVICE_ID_MATCH_DEVICE | USB_DEVICE_ID_MATCH_DEV_RANGE)
  568. #define USB_DEVICE_ID_MATCH_DEV_INFO \
  569. (USB_DEVICE_ID_MATCH_DEV_CLASS | \
  570. USB_DEVICE_ID_MATCH_DEV_SUBCLASS | \
  571. USB_DEVICE_ID_MATCH_DEV_PROTOCOL)
  572. #define USB_DEVICE_ID_MATCH_INT_INFO \
  573. (USB_DEVICE_ID_MATCH_INT_CLASS | \
  574. USB_DEVICE_ID_MATCH_INT_SUBCLASS | \
  575. USB_DEVICE_ID_MATCH_INT_PROTOCOL)
  576. /**
  577. * USB_DEVICE - macro used to describe a specific usb device
  578. * @vend: the 16 bit USB Vendor ID
  579. * @prod: the 16 bit USB Product ID
  580. *
  581. * This macro is used to create a struct usb_device_id that matches a
  582. * specific device.
  583. */
  584. #define USB_DEVICE(vend, prod) \
  585. .match_flags = USB_DEVICE_ID_MATCH_DEVICE, \
  586. .idVendor = (vend), \
  587. .idProduct = (prod)
  588. /**
  589. * USB_DEVICE_VER - describe a specific usb device with a version range
  590. * @vend: the 16 bit USB Vendor ID
  591. * @prod: the 16 bit USB Product ID
  592. * @lo: the bcdDevice_lo value
  593. * @hi: the bcdDevice_hi value
  594. *
  595. * This macro is used to create a struct usb_device_id that matches a
  596. * specific device, with a version range.
  597. */
  598. #define USB_DEVICE_VER(vend, prod, lo, hi) \
  599. .match_flags = USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION, \
  600. .idVendor = (vend), \
  601. .idProduct = (prod), \
  602. .bcdDevice_lo = (lo), \
  603. .bcdDevice_hi = (hi)
  604. /**
  605. * USB_DEVICE_INTERFACE_PROTOCOL - describe a usb device with a specific interface protocol
  606. * @vend: the 16 bit USB Vendor ID
  607. * @prod: the 16 bit USB Product ID
  608. * @pr: bInterfaceProtocol value
  609. *
  610. * This macro is used to create a struct usb_device_id that matches a
  611. * specific interface protocol of devices.
  612. */
  613. #define USB_DEVICE_INTERFACE_PROTOCOL(vend, prod, pr) \
  614. .match_flags = USB_DEVICE_ID_MATCH_DEVICE | \
  615. USB_DEVICE_ID_MATCH_INT_PROTOCOL, \
  616. .idVendor = (vend), \
  617. .idProduct = (prod), \
  618. .bInterfaceProtocol = (pr)
  619. /**
  620. * USB_DEVICE_INFO - macro used to describe a class of usb devices
  621. * @cl: bDeviceClass value
  622. * @sc: bDeviceSubClass value
  623. * @pr: bDeviceProtocol value
  624. *
  625. * This macro is used to create a struct usb_device_id that matches a
  626. * specific class of devices.
  627. */
  628. #define USB_DEVICE_INFO(cl, sc, pr) \
  629. .match_flags = USB_DEVICE_ID_MATCH_DEV_INFO, \
  630. .bDeviceClass = (cl), \
  631. .bDeviceSubClass = (sc), \
  632. .bDeviceProtocol = (pr)
  633. /**
  634. * USB_INTERFACE_INFO - macro used to describe a class of usb interfaces
  635. * @cl: bInterfaceClass value
  636. * @sc: bInterfaceSubClass value
  637. * @pr: bInterfaceProtocol value
  638. *
  639. * This macro is used to create a struct usb_device_id that matches a
  640. * specific class of interfaces.
  641. */
  642. #define USB_INTERFACE_INFO(cl, sc, pr) \
  643. .match_flags = USB_DEVICE_ID_MATCH_INT_INFO, \
  644. .bInterfaceClass = (cl), \
  645. .bInterfaceSubClass = (sc), \
  646. .bInterfaceProtocol = (pr)
  647. /**
  648. * USB_DEVICE_AND_INTERFACE_INFO - describe a specific usb device with a class of usb interfaces
  649. * @vend: the 16 bit USB Vendor ID
  650. * @prod: the 16 bit USB Product ID
  651. * @cl: bInterfaceClass value
  652. * @sc: bInterfaceSubClass value
  653. * @pr: bInterfaceProtocol value
  654. *
  655. * This macro is used to create a struct usb_device_id that matches a
  656. * specific device with a specific class of interfaces.
  657. *
  658. * This is especially useful when explicitly matching devices that have
  659. * vendor specific bDeviceClass values, but standards-compliant interfaces.
  660. */
  661. #define USB_DEVICE_AND_INTERFACE_INFO(vend, prod, cl, sc, pr) \
  662. .match_flags = USB_DEVICE_ID_MATCH_INT_INFO \
  663. | USB_DEVICE_ID_MATCH_DEVICE, \
  664. .idVendor = (vend), \
  665. .idProduct = (prod), \
  666. .bInterfaceClass = (cl), \
  667. .bInterfaceSubClass = (sc), \
  668. .bInterfaceProtocol = (pr)
  669. /* ----------------------------------------------------------------------- */
  670. /* Stuff for dynamic usb ids */
  671. struct usb_dynids {
  672. spinlock_t lock;
  673. struct list_head list;
  674. };
  675. struct usb_dynid {
  676. struct list_head node;
  677. struct usb_device_id id;
  678. };
  679. extern ssize_t usb_store_new_id(struct usb_dynids *dynids,
  680. struct device_driver *driver,
  681. const char *buf, size_t count);
  682. /**
  683. * struct usbdrv_wrap - wrapper for driver-model structure
  684. * @driver: The driver-model core driver structure.
  685. * @for_devices: Non-zero for device drivers, 0 for interface drivers.
  686. */
  687. struct usbdrv_wrap {
  688. struct device_driver driver;
  689. int for_devices;
  690. };
  691. /**
  692. * struct usb_driver - identifies USB interface driver to usbcore
  693. * @name: The driver name should be unique among USB drivers,
  694. * and should normally be the same as the module name.
  695. * @probe: Called to see if the driver is willing to manage a particular
  696. * interface on a device. If it is, probe returns zero and uses
  697. * usb_set_intfdata() to associate driver-specific data with the
  698. * interface. It may also use usb_set_interface() to specify the
  699. * appropriate altsetting. If unwilling to manage the interface,
  700. * return -ENODEV, if genuine IO errors occurred, an appropriate
  701. * negative errno value.
  702. * @disconnect: Called when the interface is no longer accessible, usually
  703. * because its device has been (or is being) disconnected or the
  704. * driver module is being unloaded.
  705. * @unlocked_ioctl: Used for drivers that want to talk to userspace through
  706. * the "usbfs" filesystem. This lets devices provide ways to
  707. * expose information to user space regardless of where they
  708. * do (or don't) show up otherwise in the filesystem.
  709. * @suspend: Called when the device is going to be suspended by the system.
  710. * @resume: Called when the device is being resumed by the system.
  711. * @reset_resume: Called when the suspended device has been reset instead
  712. * of being resumed.
  713. * @pre_reset: Called by usb_reset_device() when the device is about to be
  714. * reset. This routine must not return until the driver has no active
  715. * URBs for the device, and no more URBs may be submitted until the
  716. * post_reset method is called.
  717. * @post_reset: Called by usb_reset_device() after the device
  718. * has been reset
  719. * @id_table: USB drivers use ID table to support hotplugging.
  720. * Export this with MODULE_DEVICE_TABLE(usb,...). This must be set
  721. * or your driver's probe function will never get called.
  722. * @dynids: used internally to hold the list of dynamically added device
  723. * ids for this driver.
  724. * @drvwrap: Driver-model core structure wrapper.
  725. * @no_dynamic_id: if set to 1, the USB core will not allow dynamic ids to be
  726. * added to this driver by preventing the sysfs file from being created.
  727. * @supports_autosuspend: if set to 0, the USB core will not allow autosuspend
  728. * for interfaces bound to this driver.
  729. * @soft_unbind: if set to 1, the USB core will not kill URBs and disable
  730. * endpoints before calling the driver's disconnect method.
  731. *
  732. * USB interface drivers must provide a name, probe() and disconnect()
  733. * methods, and an id_table. Other driver fields are optional.
  734. *
  735. * The id_table is used in hotplugging. It holds a set of descriptors,
  736. * and specialized data may be associated with each entry. That table
  737. * is used by both user and kernel mode hotplugging support.
  738. *
  739. * The probe() and disconnect() methods are called in a context where
  740. * they can sleep, but they should avoid abusing the privilege. Most
  741. * work to connect to a device should be done when the device is opened,
  742. * and undone at the last close. The disconnect code needs to address
  743. * concurrency issues with respect to open() and close() methods, as
  744. * well as forcing all pending I/O requests to complete (by unlinking
  745. * them as necessary, and blocking until the unlinks complete).
  746. */
  747. struct usb_driver {
  748. const char *name;
  749. int (*probe) (struct usb_interface *intf,
  750. const struct usb_device_id *id);
  751. void (*disconnect) (struct usb_interface *intf);
  752. int (*unlocked_ioctl) (struct usb_interface *intf, unsigned int code,
  753. void *buf);
  754. int (*suspend) (struct usb_interface *intf, pm_message_t message);
  755. int (*resume) (struct usb_interface *intf);
  756. int (*reset_resume)(struct usb_interface *intf);
  757. int (*pre_reset)(struct usb_interface *intf);
  758. int (*post_reset)(struct usb_interface *intf);
  759. const struct usb_device_id *id_table;
  760. struct usb_dynids dynids;
  761. struct usbdrv_wrap drvwrap;
  762. unsigned int no_dynamic_id:1;
  763. unsigned int supports_autosuspend:1;
  764. unsigned int soft_unbind:1;
  765. };
  766. #define to_usb_driver(d) container_of(d, struct usb_driver, drvwrap.driver)
  767. /**
  768. * struct usb_device_driver - identifies USB device driver to usbcore
  769. * @name: The driver name should be unique among USB drivers,
  770. * and should normally be the same as the module name.
  771. * @probe: Called to see if the driver is willing to manage a particular
  772. * device. If it is, probe returns zero and uses dev_set_drvdata()
  773. * to associate driver-specific data with the device. If unwilling
  774. * to manage the device, return a negative errno value.
  775. * @disconnect: Called when the device is no longer accessible, usually
  776. * because it has been (or is being) disconnected or the driver's
  777. * module is being unloaded.
  778. * @suspend: Called when the device is going to be suspended by the system.
  779. * @resume: Called when the device is being resumed by the system.
  780. * @drvwrap: Driver-model core structure wrapper.
  781. * @supports_autosuspend: if set to 0, the USB core will not allow autosuspend
  782. * for devices bound to this driver.
  783. *
  784. * USB drivers must provide all the fields listed above except drvwrap.
  785. */
  786. struct usb_device_driver {
  787. const char *name;
  788. int (*probe) (struct usb_device *udev);
  789. void (*disconnect) (struct usb_device *udev);
  790. int (*suspend) (struct usb_device *udev, pm_message_t message);
  791. int (*resume) (struct usb_device *udev, pm_message_t message);
  792. struct usbdrv_wrap drvwrap;
  793. unsigned int supports_autosuspend:1;
  794. };
  795. #define to_usb_device_driver(d) container_of(d, struct usb_device_driver, \
  796. drvwrap.driver)
  797. extern struct bus_type usb_bus_type;
  798. /**
  799. * struct usb_class_driver - identifies a USB driver that wants to use the USB major number
  800. * @name: the usb class device name for this driver. Will show up in sysfs.
  801. * @devnode: Callback to provide a naming hint for a possible
  802. * device node to create.
  803. * @fops: pointer to the struct file_operations of this driver.
  804. * @minor_base: the start of the minor range for this driver.
  805. *
  806. * This structure is used for the usb_register_dev() and
  807. * usb_unregister_dev() functions, to consolidate a number of the
  808. * parameters used for them.
  809. */
  810. struct usb_class_driver {
  811. char *name;
  812. char *(*devnode)(struct device *dev, mode_t *mode);
  813. const struct file_operations *fops;
  814. int minor_base;
  815. };
  816. /*
  817. * use these in module_init()/module_exit()
  818. * and don't forget MODULE_DEVICE_TABLE(usb, ...)
  819. */
  820. extern int usb_register_driver(struct usb_driver *, struct module *,
  821. const char *);
  822. static inline int usb_register(struct usb_driver *driver)
  823. {
  824. return usb_register_driver(driver, THIS_MODULE, KBUILD_MODNAME);
  825. }
  826. extern void usb_deregister(struct usb_driver *);
  827. extern int usb_register_device_driver(struct usb_device_driver *,
  828. struct module *);
  829. extern void usb_deregister_device_driver(struct usb_device_driver *);
  830. extern int usb_register_dev(struct usb_interface *intf,
  831. struct usb_class_driver *class_driver);
  832. extern void usb_deregister_dev(struct usb_interface *intf,
  833. struct usb_class_driver *class_driver);
  834. extern int usb_disabled(void);
  835. /* ----------------------------------------------------------------------- */
  836. /*
  837. * URB support, for asynchronous request completions
  838. */
  839. /*
  840. * urb->transfer_flags:
  841. *
  842. * Note: URB_DIR_IN/OUT is automatically set in usb_submit_urb().
  843. */
  844. #define URB_SHORT_NOT_OK 0x0001 /* report short reads as errors */
  845. #define URB_ISO_ASAP 0x0002 /* iso-only, urb->start_frame
  846. * ignored */
  847. #define URB_NO_TRANSFER_DMA_MAP 0x0004 /* urb->transfer_dma valid on submit */
  848. #define URB_NO_FSBR 0x0020 /* UHCI-specific */
  849. #define URB_ZERO_PACKET 0x0040 /* Finish bulk OUT with short packet */
  850. #define URB_NO_INTERRUPT 0x0080 /* HINT: no non-error interrupt
  851. * needed */
  852. #define URB_FREE_BUFFER 0x0100 /* Free transfer buffer with the URB */
  853. /* The following flags are used internally by usbcore and HCDs */
  854. #define URB_DIR_IN 0x0200 /* Transfer from device to host */
  855. #define URB_DIR_OUT 0
  856. #define URB_DIR_MASK URB_DIR_IN
  857. #define URB_DMA_MAP_SINGLE 0x00010000 /* Non-scatter-gather mapping */
  858. #define URB_DMA_MAP_PAGE 0x00020000 /* HCD-unsupported S-G */
  859. #define URB_DMA_MAP_SG 0x00040000 /* HCD-supported S-G */
  860. #define URB_MAP_LOCAL 0x00080000 /* HCD-local-memory mapping */
  861. #define URB_SETUP_MAP_SINGLE 0x00100000 /* Setup packet DMA mapped */
  862. #define URB_SETUP_MAP_LOCAL 0x00200000 /* HCD-local setup packet */
  863. #define URB_DMA_SG_COMBINED 0x00400000 /* S-G entries were combined */
  864. #define URB_ALIGNED_TEMP_BUFFER 0x00800000 /* Temp buffer was alloc'd */
  865. struct usb_iso_packet_descriptor {
  866. unsigned int offset;
  867. unsigned int length; /* expected length */
  868. unsigned int actual_length;
  869. int status;
  870. };
  871. struct urb;
  872. struct usb_anchor {
  873. struct list_head urb_list;
  874. wait_queue_head_t wait;
  875. spinlock_t lock;
  876. unsigned int poisoned:1;
  877. };
  878. static inline void init_usb_anchor(struct usb_anchor *anchor)
  879. {
  880. INIT_LIST_HEAD(&anchor->urb_list);
  881. init_waitqueue_head(&anchor->wait);
  882. spin_lock_init(&anchor->lock);
  883. }
  884. typedef void (*usb_complete_t)(struct urb *);
  885. /**
  886. * struct urb - USB Request Block
  887. * @urb_list: For use by current owner of the URB.
  888. * @anchor_list: membership in the list of an anchor
  889. * @anchor: to anchor URBs to a common mooring
  890. * @ep: Points to the endpoint's data structure. Will eventually
  891. * replace @pipe.
  892. * @pipe: Holds endpoint number, direction, type, and more.
  893. * Create these values with the eight macros available;
  894. * usb_{snd,rcv}TYPEpipe(dev,endpoint), where the TYPE is "ctrl"
  895. * (control), "bulk", "int" (interrupt), or "iso" (isochronous).
  896. * For example usb_sndbulkpipe() or usb_rcvintpipe(). Endpoint
  897. * numbers range from zero to fifteen. Note that "in" endpoint two
  898. * is a different endpoint (and pipe) from "out" endpoint two.
  899. * The current configuration controls the existence, type, and
  900. * maximum packet size of any given endpoint.
  901. * @stream_id: the endpoint's stream ID for bulk streams
  902. * @dev: Identifies the USB device to perform the request.
  903. * @status: This is read in non-iso completion functions to get the
  904. * status of the particular request. ISO requests only use it
  905. * to tell whether the URB was unlinked; detailed status for
  906. * each frame is in the fields of the iso_frame-desc.
  907. * @transfer_flags: A variety of flags may be used to affect how URB
  908. * submission, unlinking, or operation are handled. Different
  909. * kinds of URB can use different flags.
  910. * @transfer_buffer: This identifies the buffer to (or from) which the I/O
  911. * request will be performed unless URB_NO_TRANSFER_DMA_MAP is set
  912. * (however, do not leave garbage in transfer_buffer even then).
  913. * This buffer must be suitable for DMA; allocate it with
  914. * kmalloc() or equivalent. For transfers to "in" endpoints, contents
  915. * of this buffer will be modified. This buffer is used for the data
  916. * stage of control transfers.
  917. * @transfer_dma: When transfer_flags includes URB_NO_TRANSFER_DMA_MAP,
  918. * the device driver is saying that it provided this DMA address,
  919. * which the host controller driver should use in preference to the
  920. * transfer_buffer.
  921. * @sg: scatter gather buffer list
  922. * @num_sgs: number of entries in the sg list
  923. * @transfer_buffer_length: How big is transfer_buffer. The transfer may
  924. * be broken up into chunks according to the current maximum packet
  925. * size for the endpoint, which is a function of the configuration
  926. * and is encoded in the pipe. When the length is zero, neither
  927. * transfer_buffer nor transfer_dma is used.
  928. * @actual_length: This is read in non-iso completion functions, and
  929. * it tells how many bytes (out of transfer_buffer_length) were
  930. * transferred. It will normally be the same as requested, unless
  931. * either an error was reported or a short read was performed.
  932. * The URB_SHORT_NOT_OK transfer flag may be used to make such
  933. * short reads be reported as errors.
  934. * @setup_packet: Only used for control transfers, this points to eight bytes
  935. * of setup data. Control transfers always start by sending this data
  936. * to the device. Then transfer_buffer is read or written, if needed.
  937. * @setup_dma: DMA pointer for the setup packet. The caller must not use
  938. * this field; setup_packet must point to a valid buffer.
  939. * @start_frame: Returns the initial frame for isochronous transfers.
  940. * @number_of_packets: Lists the number of ISO transfer buffers.
  941. * @interval: Specifies the polling interval for interrupt or isochronous
  942. * transfers. The units are frames (milliseconds) for full and low
  943. * speed devices, and microframes (1/8 millisecond) for highspeed
  944. * and SuperSpeed devices.
  945. * @error_count: Returns the number of ISO transfers that reported errors.
  946. * @context: For use in completion functions. This normally points to
  947. * request-specific driver context.
  948. * @complete: Completion handler. This URB is passed as the parameter to the
  949. * completion function. The completion function may then do what
  950. * it likes with the URB, including resubmitting or freeing it.
  951. * @iso_frame_desc: Used to provide arrays of ISO transfer buffers and to
  952. * collect the transfer status for each buffer.
  953. *
  954. * This structure identifies USB transfer requests. URBs must be allocated by
  955. * calling usb_alloc_urb() and freed with a call to usb_free_urb().
  956. * Initialization may be done using various usb_fill_*_urb() functions. URBs
  957. * are submitted using usb_submit_urb(), and pending requests may be canceled
  958. * using usb_unlink_urb() or usb_kill_urb().
  959. *
  960. * Data Transfer Buffers:
  961. *
  962. * Normally drivers provide I/O buffers allocated with kmalloc() or otherwise
  963. * taken from the general page pool. That is provided by transfer_buffer
  964. * (control requests also use setup_packet), and host controller drivers
  965. * perform a dma mapping (and unmapping) for each buffer transferred. Those
  966. * mapping operations can be expensive on some platforms (perhaps using a dma
  967. * bounce buffer or talking to an IOMMU),
  968. * although they're cheap on commodity x86 and ppc hardware.
  969. *
  970. * Alternatively, drivers may pass the URB_NO_TRANSFER_DMA_MAP transfer flag,
  971. * which tells the host controller driver that no such mapping is needed for
  972. * the transfer_buffer since
  973. * the device driver is DMA-aware. For example, a device driver might
  974. * allocate a DMA buffer with usb_alloc_coherent() or call usb_buffer_map().
  975. * When this transfer flag is provided, host controller drivers will
  976. * attempt to use the dma address found in the transfer_dma
  977. * field rather than determining a dma address themselves.
  978. *
  979. * Note that transfer_buffer must still be set if the controller
  980. * does not support DMA (as indicated by bus.uses_dma) and when talking
  981. * to root hub. If you have to trasfer between highmem zone and the device
  982. * on such controller, create a bounce buffer or bail out with an error.
  983. * If transfer_buffer cannot be set (is in highmem) and the controller is DMA
  984. * capable, assign NULL to it, so that usbmon knows not to use the value.
  985. * The setup_packet must always be set, so it cannot be located in highmem.
  986. *
  987. * Initialization:
  988. *
  989. * All URBs submitted must initialize the dev, pipe, transfer_flags (may be
  990. * zero), and complete fields. All URBs must also initialize
  991. * transfer_buffer and transfer_buffer_length. They may provide the
  992. * URB_SHORT_NOT_OK transfer flag, indicating that short reads are
  993. * to be treated as errors; that flag is invalid for write requests.
  994. *
  995. * Bulk URBs may
  996. * use the URB_ZERO_PACKET transfer flag, indicating that bulk OUT transfers
  997. * should always terminate with a short packet, even if it means adding an
  998. * extra zero length packet.
  999. *
  1000. * Control URBs must provide a valid pointer in the setup_packet field.
  1001. * Unlike the transfer_buffer, the setup_packet may not be mapped for DMA
  1002. * beforehand.
  1003. *
  1004. * Interrupt URBs must provide an interval, saying how often (in milliseconds
  1005. * or, for highspeed devices, 125 microsecond units)
  1006. * to poll for transfers. After the URB has been submitted, the interval
  1007. * field reflects how the transfer was actually scheduled.
  1008. * The polling interval may be more frequent than requested.
  1009. * For example, some controllers have a maximum interval of 32 milliseconds,
  1010. * while others support intervals of up to 1024 milliseconds.
  1011. * Isochronous URBs also have transfer intervals. (Note that for isochronous
  1012. * endpoints, as well as high speed interrupt endpoints, the encoding of
  1013. * the transfer interval in the endpoint descriptor is logarithmic.
  1014. * Device drivers must convert that value to linear units themselves.)
  1015. *
  1016. * Isochronous URBs normally use the URB_ISO_ASAP transfer flag, telling
  1017. * the host controller to schedule the transfer as soon as bandwidth
  1018. * utilization allows, and then set start_frame to reflect the actual frame
  1019. * selected during submission. Otherwise drivers must specify the start_frame
  1020. * and handle the case where the transfer can't begin then. However, drivers
  1021. * won't know how bandwidth is currently allocated, and while they can
  1022. * find the current frame using usb_get_current_frame_number () they can't
  1023. * know the range for that frame number. (Ranges for frame counter values
  1024. * are HC-specific, and can go from 256 to 65536 frames from "now".)
  1025. *
  1026. * Isochronous URBs have a different data transfer model, in part because
  1027. * the quality of service is only "best effort". Callers provide specially
  1028. * allocated URBs, with number_of_packets worth of iso_frame_desc structures
  1029. * at the end. Each such packet is an individual ISO transfer. Isochronous
  1030. * URBs are normally queued, submitted by drivers to arrange that
  1031. * transfers are at least double buffered, and then explicitly resubmitted
  1032. * in completion handlers, so
  1033. * that data (such as audio or video) streams at as constant a rate as the
  1034. * host controller scheduler can support.
  1035. *
  1036. * Completion Callbacks:
  1037. *
  1038. * The completion callback is made in_interrupt(), and one of the first
  1039. * things that a completion handler should do is check the status field.
  1040. * The status field is provided for all URBs. It is used to report
  1041. * unlinked URBs, and status for all non-ISO transfers. It should not
  1042. * be examined before the URB is returned to the completion handler.
  1043. *
  1044. * The context field is normally used to link URBs back to the relevant
  1045. * driver or request state.
  1046. *
  1047. * When the completion callback is invoked for non-isochronous URBs, the
  1048. * actual_length field tells how many bytes were transferred. This field
  1049. * is updated even when the URB terminated with an error or was unlinked.
  1050. *
  1051. * ISO transfer status is reported in the status and actual_length fields
  1052. * of the iso_frame_desc array, and the number of errors is reported in
  1053. * error_count. Completion callbacks for ISO transfers will normally
  1054. * (re)submit URBs to ensure a constant transfer rate.
  1055. *
  1056. * Note that even fields marked "public" should not be touched by the driver
  1057. * when the urb is owned by the hcd, that is, since the call to
  1058. * usb_submit_urb() till the entry into the completion routine.
  1059. */
  1060. struct urb {
  1061. /* private: usb core and host controller only fields in the urb */
  1062. struct kref kref; /* reference count of the URB */
  1063. void *hcpriv; /* private data for host controller */
  1064. atomic_t use_count; /* concurrent submissions counter */
  1065. atomic_t reject; /* submissions will fail */
  1066. int unlinked; /* unlink error code */
  1067. /* public: documented fields in the urb that can be used by drivers */
  1068. struct list_head urb_list; /* list head for use by the urb's
  1069. * current owner */
  1070. struct list_head anchor_list; /* the URB may be anchored */
  1071. struct usb_anchor *anchor;
  1072. struct usb_device *dev; /* (in) pointer to associated device */
  1073. struct usb_host_endpoint *ep; /* (internal) pointer to endpoint */
  1074. unsigned int pipe; /* (in) pipe information */
  1075. unsigned int stream_id; /* (in) stream ID */
  1076. int status; /* (return) non-ISO status */
  1077. unsigned int transfer_flags; /* (in) URB_SHORT_NOT_OK | ...*/
  1078. void *transfer_buffer; /* (in) associated data buffer */
  1079. dma_addr_t transfer_dma; /* (in) dma addr for transfer_buffer */
  1080. struct scatterlist *sg; /* (in) scatter gather buffer list */
  1081. int num_sgs; /* (in) number of entries in the sg list */
  1082. u32 transfer_buffer_length; /* (in) data buffer length */
  1083. u32 actual_length; /* (return) actual transfer length */
  1084. unsigned char *setup_packet; /* (in) setup packet (control only) */
  1085. dma_addr_t setup_dma; /* (in) dma addr for setup_packet */
  1086. int start_frame; /* (modify) start frame (ISO) */
  1087. int number_of_packets; /* (in) number of ISO packets */
  1088. int interval; /* (modify) transfer interval
  1089. * (INT/ISO) */
  1090. int error_count; /* (return) number of ISO errors */
  1091. void *context; /* (in) context for completion */
  1092. usb_complete_t complete; /* (in) completion routine */
  1093. struct usb_iso_packet_d