usb_gadget.h 34 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881
  1. /*
  2. * <linux/usb_gadget.h>
  3. *
  4. * We call the USB code inside a Linux-based peripheral device a "gadget"
  5. * driver, except for the hardware-specific bus glue. One USB host can
  6. * master many USB gadgets, but the gadgets are only slaved to one host.
  7. *
  8. *
  9. * (C) Copyright 2002-2004 by David Brownell
  10. * All Rights Reserved.
  11. *
  12. * This software is licensed under the GNU GPL version 2.
  13. */
  14. #ifndef __LINUX_USB_GADGET_H
  15. #define __LINUX_USB_GADGET_H
  16. #ifdef __KERNEL__
  17. struct usb_ep;
  18. /**
  19. * struct usb_request - describes one i/o request
  20. * @buf: Buffer used for data. Always provide this; some controllers
  21. * only use PIO, or don't use DMA for some endpoints.
  22. * @dma: DMA address corresponding to 'buf'. If you don't set this
  23. * field, and the usb controller needs one, it is responsible
  24. * for mapping and unmapping the buffer.
  25. * @length: Length of that data
  26. * @no_interrupt: If true, hints that no completion irq is needed.
  27. * Helpful sometimes with deep request queues that are handled
  28. * directly by DMA controllers.
  29. * @zero: If true, when writing data, makes the last packet be "short"
  30. * by adding a zero length packet as needed;
  31. * @short_not_ok: When reading data, makes short packets be
  32. * treated as errors (queue stops advancing till cleanup).
  33. * @complete: Function called when request completes, so this request and
  34. * its buffer may be re-used.
  35. * Reads terminate with a short packet, or when the buffer fills,
  36. * whichever comes first. When writes terminate, some data bytes
  37. * will usually still be in flight (often in a hardware fifo).
  38. * Errors (for reads or writes) stop the queue from advancing
  39. * until the completion function returns, so that any transfers
  40. * invalidated by the error may first be dequeued.
  41. * @context: For use by the completion callback
  42. * @list: For use by the gadget driver.
  43. * @status: Reports completion code, zero or a negative errno.
  44. * Normally, faults block the transfer queue from advancing until
  45. * the completion callback returns.
  46. * Code "-ESHUTDOWN" indicates completion caused by device disconnect,
  47. * or when the driver disabled the endpoint.
  48. * @actual: Reports bytes transferred to/from the buffer. For reads (OUT
  49. * transfers) this may be less than the requested length. If the
  50. * short_not_ok flag is set, short reads are treated as errors
  51. * even when status otherwise indicates successful completion.
  52. * Note that for writes (IN transfers) some data bytes may still
  53. * reside in a device-side FIFO when the request is reported as
  54. * complete.
  55. *
  56. * These are allocated/freed through the endpoint they're used with. The
  57. * hardware's driver can add extra per-request data to the memory it returns,
  58. * which often avoids separate memory allocations (potential failures),
  59. * later when the request is queued.
  60. *
  61. * Request flags affect request handling, such as whether a zero length
  62. * packet is written (the "zero" flag), whether a short read should be
  63. * treated as an error (blocking request queue advance, the "short_not_ok"
  64. * flag), or hinting that an interrupt is not required (the "no_interrupt"
  65. * flag, for use with deep request queues).
  66. *
  67. * Bulk endpoints can use any size buffers, and can also be used for interrupt
  68. * transfers. interrupt-only endpoints can be much less functional.
  69. */
  70. // NOTE this is analagous to 'struct urb' on the host side,
  71. // except that it's thinner and promotes more pre-allocation.
  72. struct usb_request {
  73. void *buf;
  74. unsigned length;
  75. dma_addr_t dma;
  76. unsigned no_interrupt:1;
  77. unsigned zero:1;
  78. unsigned short_not_ok:1;
  79. void (*complete)(struct usb_ep *ep,
  80. struct usb_request *req);
  81. void *context;
  82. struct list_head list;
  83. int status;
  84. unsigned actual;
  85. };
  86. /*-------------------------------------------------------------------------*/
  87. /* endpoint-specific parts of the api to the usb controller hardware.
  88. * unlike the urb model, (de)multiplexing layers are not required.
  89. * (so this api could slash overhead if used on the host side...)
  90. *
  91. * note that device side usb controllers commonly differ in how many
  92. * endpoints they support, as well as their capabilities.
  93. */
  94. struct usb_ep_ops {
  95. int (*enable) (struct usb_ep *ep,
  96. const struct usb_endpoint_descriptor *desc);
  97. int (*disable) (struct usb_ep *ep);
  98. struct usb_request *(*alloc_request) (struct usb_ep *ep,
  99. gfp_t gfp_flags);
  100. void (*free_request) (struct usb_ep *ep, struct usb_request *req);
  101. void *(*alloc_buffer) (struct usb_ep *ep, unsigned bytes,
  102. dma_addr_t *dma, gfp_t gfp_flags);
  103. void (*free_buffer) (struct usb_ep *ep, void *buf, dma_addr_t dma,
  104. unsigned bytes);
  105. // NOTE: on 2.6, drivers may also use dma_map() and
  106. // dma_sync_single_*() to directly manage dma overhead.
  107. int (*queue) (struct usb_ep *ep, struct usb_request *req,
  108. gfp_t gfp_flags);
  109. int (*dequeue) (struct usb_ep *ep, struct usb_request *req);
  110. int (*set_halt) (struct usb_ep *ep, int value);
  111. int (*fifo_status) (struct usb_ep *ep);
  112. void (*fifo_flush) (struct usb_ep *ep);
  113. };
  114. /**
  115. * struct usb_ep - device side representation of USB endpoint
  116. * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk"
  117. * @ops: Function pointers used to access hardware-specific operations.
  118. * @ep_list:the gadget's ep_list holds all of its endpoints
  119. * @maxpacket:The maximum packet size used on this endpoint. The initial
  120. * value can sometimes be reduced (hardware allowing), according to
  121. * the endpoint descriptor used to configure the endpoint.
  122. * @driver_data:for use by the gadget driver. all other fields are
  123. * read-only to gadget drivers.
  124. *
  125. * the bus controller driver lists all the general purpose endpoints in
  126. * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list,
  127. * and is accessed only in response to a driver setup() callback.
  128. */
  129. struct usb_ep {
  130. void *driver_data;
  131. const char *name;
  132. const struct usb_ep_ops *ops;
  133. struct list_head ep_list;
  134. unsigned maxpacket:16;
  135. };
  136. /*-------------------------------------------------------------------------*/
  137. /**
  138. * usb_ep_enable - configure endpoint, making it usable
  139. * @ep:the endpoint being configured. may not be the endpoint named "ep0".
  140. * drivers discover endpoints through the ep_list of a usb_gadget.
  141. * @desc:descriptor for desired behavior. caller guarantees this pointer
  142. * remains valid until the endpoint is disabled; the data byte order
  143. * is little-endian (usb-standard).
  144. *
  145. * when configurations are set, or when interface settings change, the driver
  146. * will enable or disable the relevant endpoints. while it is enabled, an
  147. * endpoint may be used for i/o until the driver receives a disconnect() from
  148. * the host or until the endpoint is disabled.
  149. *
  150. * the ep0 implementation (which calls this routine) must ensure that the
  151. * hardware capabilities of each endpoint match the descriptor provided
  152. * for it. for example, an endpoint named "ep2in-bulk" would be usable
  153. * for interrupt transfers as well as bulk, but it likely couldn't be used
  154. * for iso transfers or for endpoint 14. some endpoints are fully
  155. * configurable, with more generic names like "ep-a". (remember that for
  156. * USB, "in" means "towards the USB master".)
  157. *
  158. * returns zero, or a negative error code.
  159. */
  160. static inline int
  161. usb_ep_enable (struct usb_ep *ep, const struct usb_endpoint_descriptor *desc)
  162. {
  163. return ep->ops->enable (ep, desc);
  164. }
  165. /**
  166. * usb_ep_disable - endpoint is no longer usable
  167. * @ep:the endpoint being unconfigured. may not be the endpoint named "ep0".
  168. *
  169. * no other task may be using this endpoint when this is called.
  170. * any pending and uncompleted requests will complete with status
  171. * indicating disconnect (-ESHUTDOWN) before this call returns.
  172. * gadget drivers must call usb_ep_enable() again before queueing
  173. * requests to the endpoint.
  174. *
  175. * returns zero, or a negative error code.
  176. */
  177. static inline int
  178. usb_ep_disable (struct usb_ep *ep)
  179. {
  180. return ep->ops->disable (ep);
  181. }
  182. /**
  183. * usb_ep_alloc_request - allocate a request object to use with this endpoint
  184. * @ep:the endpoint to be used with with the request
  185. * @gfp_flags:GFP_* flags to use
  186. *
  187. * Request objects must be allocated with this call, since they normally
  188. * need controller-specific setup and may even need endpoint-specific
  189. * resources such as allocation of DMA descriptors.
  190. * Requests may be submitted with usb_ep_queue(), and receive a single
  191. * completion callback. Free requests with usb_ep_free_request(), when
  192. * they are no longer needed.
  193. *
  194. * Returns the request, or null if one could not be allocated.
  195. */
  196. static inline struct usb_request *
  197. usb_ep_alloc_request (struct usb_ep *ep, gfp_t gfp_flags)
  198. {
  199. return ep->ops->alloc_request (ep, gfp_flags);
  200. }
  201. /**
  202. * usb_ep_free_request - frees a request object
  203. * @ep:the endpoint associated with the request
  204. * @req:the request being freed
  205. *
  206. * Reverses the effect of usb_ep_alloc_request().
  207. * Caller guarantees the request is not queued, and that it will
  208. * no longer be requeued (or otherwise used).
  209. */
  210. static inline void
  211. usb_ep_free_request (struct usb_ep *ep, struct usb_request *req)
  212. {
  213. ep->ops->free_request (ep, req);
  214. }
  215. /**
  216. * usb_ep_alloc_buffer - allocate an I/O buffer
  217. * @ep:the endpoint associated with the buffer
  218. * @len:length of the desired buffer
  219. * @dma:pointer to the buffer's DMA address; must be valid
  220. * @gfp_flags:GFP_* flags to use
  221. *
  222. * Returns a new buffer, or null if one could not be allocated.
  223. * The buffer is suitably aligned for dma, if that endpoint uses DMA,
  224. * and the caller won't have to care about dma-inconsistency
  225. * or any hidden "bounce buffer" mechanism. No additional per-request
  226. * DMA mapping will be required for such buffers.
  227. * Free it later with usb_ep_free_buffer().
  228. *
  229. * You don't need to use this call to allocate I/O buffers unless you
  230. * want to make sure drivers don't incur costs for such "bounce buffer"
  231. * copies or per-request DMA mappings.
  232. */
  233. static inline void *
  234. usb_ep_alloc_buffer (struct usb_ep *ep, unsigned len, dma_addr_t *dma,
  235. gfp_t gfp_flags)
  236. {
  237. return ep->ops->alloc_buffer (ep, len, dma, gfp_flags);
  238. }
  239. /**
  240. * usb_ep_free_buffer - frees an i/o buffer
  241. * @ep:the endpoint associated with the buffer
  242. * @buf:CPU view address of the buffer
  243. * @dma:the buffer's DMA address
  244. * @len:length of the buffer
  245. *
  246. * reverses the effect of usb_ep_alloc_buffer().
  247. * caller guarantees the buffer will no longer be accessed
  248. */
  249. static inline void
  250. usb_ep_free_buffer (struct usb_ep *ep, void *buf, dma_addr_t dma, unsigned len)
  251. {
  252. ep->ops->free_buffer (ep, buf, dma, len);
  253. }
  254. /**
  255. * usb_ep_queue - queues (submits) an I/O request to an endpoint.
  256. * @ep:the endpoint associated with the request
  257. * @req:the request being submitted
  258. * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
  259. * pre-allocate all necessary memory with the request.
  260. *
  261. * This tells the device controller to perform the specified request through
  262. * that endpoint (reading or writing a buffer). When the request completes,
  263. * including being canceled by usb_ep_dequeue(), the request's completion
  264. * routine is called to return the request to the driver. Any endpoint
  265. * (except control endpoints like ep0) may have more than one transfer
  266. * request queued; they complete in FIFO order. Once a gadget driver
  267. * submits a request, that request may not be examined or modified until it
  268. * is given back to that driver through the completion callback.
  269. *
  270. * Each request is turned into one or more packets. The controller driver
  271. * never merges adjacent requests into the same packet. OUT transfers
  272. * will sometimes use data that's already buffered in the hardware.
  273. * Drivers can rely on the fact that the first byte of the request's buffer
  274. * always corresponds to the first byte of some USB packet, for both
  275. * IN and OUT transfers.
  276. *
  277. * Bulk endpoints can queue any amount of data; the transfer is packetized
  278. * automatically. The last packet will be short if the request doesn't fill it
  279. * out completely. Zero length packets (ZLPs) should be avoided in portable
  280. * protocols since not all usb hardware can successfully handle zero length
  281. * packets. (ZLPs may be explicitly written, and may be implicitly written if
  282. * the request 'zero' flag is set.) Bulk endpoints may also be used
  283. * for interrupt transfers; but the reverse is not true, and some endpoints
  284. * won't support every interrupt transfer. (Such as 768 byte packets.)
  285. *
  286. * Interrupt-only endpoints are less functional than bulk endpoints, for
  287. * example by not supporting queueing or not handling buffers that are
  288. * larger than the endpoint's maxpacket size. They may also treat data
  289. * toggle differently.
  290. *
  291. * Control endpoints ... after getting a setup() callback, the driver queues
  292. * one response (even if it would be zero length). That enables the
  293. * status ack, after transfering data as specified in the response. Setup
  294. * functions may return negative error codes to generate protocol stalls.
  295. * (Note that some USB device controllers disallow protocol stall responses
  296. * in some cases.) When control responses are deferred (the response is
  297. * written after the setup callback returns), then usb_ep_set_halt() may be
  298. * used on ep0 to trigger protocol stalls.
  299. *
  300. * For periodic endpoints, like interrupt or isochronous ones, the usb host
  301. * arranges to poll once per interval, and the gadget driver usually will
  302. * have queued some data to transfer at that time.
  303. *
  304. * Returns zero, or a negative error code. Endpoints that are not enabled
  305. * report errors; errors will also be
  306. * reported when the usb peripheral is disconnected.
  307. */
  308. static inline int
  309. usb_ep_queue (struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags)
  310. {
  311. return ep->ops->queue (ep, req, gfp_flags);
  312. }
  313. /**
  314. * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
  315. * @ep:the endpoint associated with the request
  316. * @req:the request being canceled
  317. *
  318. * if the request is still active on the endpoint, it is dequeued and its
  319. * completion routine is called (with status -ECONNRESET); else a negative
  320. * error code is returned.
  321. *
  322. * note that some hardware can't clear out write fifos (to unlink the request
  323. * at the head of the queue) except as part of disconnecting from usb. such
  324. * restrictions prevent drivers from supporting configuration changes,
  325. * even to configuration zero (a "chapter 9" requirement).
  326. */
  327. static inline int usb_ep_dequeue (struct usb_ep *ep, struct usb_request *req)
  328. {
  329. return ep->ops->dequeue (ep, req);
  330. }
  331. /**
  332. * usb_ep_set_halt - sets the endpoint halt feature.
  333. * @ep: the non-isochronous endpoint being stalled
  334. *
  335. * Use this to stall an endpoint, perhaps as an error report.
  336. * Except for control endpoints,
  337. * the endpoint stays halted (will not stream any data) until the host
  338. * clears this feature; drivers may need to empty the endpoint's request
  339. * queue first, to make sure no inappropriate transfers happen.
  340. *
  341. * Note that while an endpoint CLEAR_FEATURE will be invisible to the
  342. * gadget driver, a SET_INTERFACE will not be. To reset endpoints for the
  343. * current altsetting, see usb_ep_clear_halt(). When switching altsettings,
  344. * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
  345. *
  346. * Returns zero, or a negative error code. On success, this call sets
  347. * underlying hardware state that blocks data transfers.
  348. * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
  349. * transfer requests are still queued, or if the controller hardware
  350. * (usually a FIFO) still holds bytes that the host hasn't collected.
  351. */
  352. static inline int
  353. usb_ep_set_halt (struct usb_ep *ep)
  354. {
  355. return ep->ops->set_halt (ep, 1);
  356. }
  357. /**
  358. * usb_ep_clear_halt - clears endpoint halt, and resets toggle
  359. * @ep:the bulk or interrupt endpoint being reset
  360. *
  361. * Use this when responding to the standard usb "set interface" request,
  362. * for endpoints that aren't reconfigured, after clearing any other state
  363. * in the endpoint's i/o queue.
  364. *
  365. * Returns zero, or a negative error code. On success, this call clears
  366. * the underlying hardware state reflecting endpoint halt and data toggle.
  367. * Note that some hardware can't support this request (like pxa2xx_udc),
  368. * and accordingly can't correctly implement interface altsettings.
  369. */
  370. static inline int
  371. usb_ep_clear_halt (struct usb_ep *ep)
  372. {
  373. return ep->ops->set_halt (ep, 0);
  374. }
  375. /**
  376. * usb_ep_fifo_status - returns number of bytes in fifo, or error
  377. * @ep: the endpoint whose fifo status is being checked.
  378. *
  379. * FIFO endpoints may have "unclaimed data" in them in certain cases,
  380. * such as after aborted transfers. Hosts may not have collected all
  381. * the IN data written by the gadget driver (and reported by a request
  382. * completion). The gadget driver may not have collected all the data
  383. * written OUT to it by the host. Drivers that need precise handling for
  384. * fault reporting or recovery may need to use this call.
  385. *
  386. * This returns the number of such bytes in the fifo, or a negative
  387. * errno if the endpoint doesn't use a FIFO or doesn't support such
  388. * precise handling.
  389. */
  390. static inline int
  391. usb_ep_fifo_status (struct usb_ep *ep)
  392. {
  393. if (ep->ops->fifo_status)
  394. return ep->ops->fifo_status (ep);
  395. else
  396. return -EOPNOTSUPP;
  397. }
  398. /**
  399. * usb_ep_fifo_flush - flushes contents of a fifo
  400. * @ep: the endpoint whose fifo is being flushed.
  401. *
  402. * This call may be used to flush the "unclaimed data" that may exist in
  403. * an endpoint fifo after abnormal transaction terminations. The call
  404. * must never be used except when endpoint is not being used for any
  405. * protocol translation.
  406. */
  407. static inline void
  408. usb_ep_fifo_flush (struct usb_ep *ep)
  409. {
  410. if (ep->ops->fifo_flush)
  411. ep->ops->fifo_flush (ep);
  412. }
  413. /*-------------------------------------------------------------------------*/
  414. struct usb_gadget;
  415. /* the rest of the api to the controller hardware: device operations,
  416. * which don't involve endpoints (or i/o).
  417. */
  418. struct usb_gadget_ops {
  419. int (*get_frame)(struct usb_gadget *);
  420. int (*wakeup)(struct usb_gadget *);
  421. int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
  422. int (*vbus_session) (struct usb_gadget *, int is_active);
  423. int (*vbus_draw) (struct usb_gadget *, unsigned mA);
  424. int (*pullup) (struct usb_gadget *, int is_on);
  425. int (*ioctl)(struct usb_gadget *,
  426. unsigned code, unsigned long param);
  427. };
  428. /**
  429. * struct usb_gadget - represents a usb slave device
  430. * @ops: Function pointers used to access hardware-specific operations.
  431. * @ep0: Endpoint zero, used when reading or writing responses to
  432. * driver setup() requests
  433. * @ep_list: List of other endpoints supported by the device.
  434. * @speed: Speed of current connection to USB host.
  435. * @is_dualspeed: True if the controller supports both high and full speed
  436. * operation. If it does, the gadget driver must also support both.
  437. * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
  438. * gadget driver must provide a USB OTG descriptor.
  439. * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable
  440. * is in the Mini-AB jack, and HNP has been used to switch roles
  441. * so that the "A" device currently acts as A-Peripheral, not A-Host.
  442. * @a_hnp_support: OTG device feature flag, indicating that the A-Host
  443. * supports HNP at this port.
  444. * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
  445. * only supports HNP on a different root port.
  446. * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
  447. * enabled HNP support.
  448. * @name: Identifies the controller hardware type. Used in diagnostics
  449. * and sometimes configuration.
  450. * @dev: Driver model state for this abstract device.
  451. *
  452. * Gadgets have a mostly-portable "gadget driver" implementing device
  453. * functions, handling all usb configurations and interfaces. Gadget
  454. * drivers talk to hardware-specific code indirectly, through ops vectors.
  455. * That insulates the gadget driver from hardware details, and packages
  456. * the hardware endpoints through generic i/o queues. The "usb_gadget"
  457. * and "usb_ep" interfaces provide that insulation from the hardware.
  458. *
  459. * Except for the driver data, all fields in this structure are
  460. * read-only to the gadget driver. That driver data is part of the
  461. * "driver model" infrastructure in 2.6 (and later) kernels, and for
  462. * earlier systems is grouped in a similar structure that's not known
  463. * to the rest of the kernel.
  464. *
  465. * Values of the three OTG device feature flags are updated before the
  466. * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
  467. * driver suspend() calls. They are valid only when is_otg, and when the
  468. * device is acting as a B-Peripheral (so is_a_peripheral is false).
  469. */
  470. struct usb_gadget {
  471. /* readonly to gadget driver */
  472. const struct usb_gadget_ops *ops;
  473. struct usb_ep *ep0;
  474. struct list_head ep_list; /* of usb_ep */
  475. enum usb_device_speed speed;
  476. unsigned is_dualspeed:1;
  477. unsigned is_otg:1;
  478. unsigned is_a_peripheral:1;
  479. unsigned b_hnp_enable:1;
  480. unsigned a_hnp_support:1;
  481. unsigned a_alt_hnp_support:1;
  482. const char *name;
  483. struct device dev;
  484. };
  485. static inline void set_gadget_data (struct usb_gadget *gadget, void *data)
  486. { dev_set_drvdata (&gadget->dev, data); }
  487. static inline void *get_gadget_data (struct usb_gadget *gadget)
  488. { return dev_get_drvdata (&gadget->dev); }
  489. /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
  490. #define gadget_for_each_ep(tmp,gadget) \
  491. list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
  492. /**
  493. * usb_gadget_frame_number - returns the current frame number
  494. * @gadget: controller that reports the frame number
  495. *
  496. * Returns the usb frame number, normally eleven bits from a SOF packet,
  497. * or negative errno if this device doesn't support this capability.
  498. */
  499. static inline int usb_gadget_frame_number (struct usb_gadget *gadget)
  500. {
  501. return gadget->ops->get_frame (gadget);
  502. }
  503. /**
  504. * usb_gadget_wakeup - tries to wake up the host connected to this gadget
  505. * @gadget: controller used to wake up the host
  506. *
  507. * Returns zero on success, else negative error code if the hardware
  508. * doesn't support such attempts, or its support has not been enabled
  509. * by the usb host. Drivers must return device descriptors that report
  510. * their ability to support this, or hosts won't enable it.
  511. *
  512. * This may also try to use SRP to wake the host and start enumeration,
  513. * even if OTG isn't otherwise in use. OTG devices may also start
  514. * remote wakeup even when hosts don't explicitly enable it.
  515. */
  516. static inline int usb_gadget_wakeup (struct usb_gadget *gadget)
  517. {
  518. if (!gadget->ops->wakeup)
  519. return -EOPNOTSUPP;
  520. return gadget->ops->wakeup (gadget);
  521. }
  522. /**
  523. * usb_gadget_set_selfpowered - sets the device selfpowered feature.
  524. * @gadget:the device being declared as self-powered
  525. *
  526. * this affects the device status reported by the hardware driver
  527. * to reflect that it now has a local power supply.
  528. *
  529. * returns zero on success, else negative errno.
  530. */
  531. static inline int
  532. usb_gadget_set_selfpowered (struct usb_gadget *gadget)
  533. {
  534. if (!gadget->ops->set_selfpowered)
  535. return -EOPNOTSUPP;
  536. return gadget->ops->set_selfpowered (gadget, 1);
  537. }
  538. /**
  539. * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
  540. * @gadget:the device being declared as bus-powered
  541. *
  542. * this affects the device status reported by the hardware driver.
  543. * some hardware may not support bus-powered operation, in which
  544. * case this feature's value can never change.
  545. *
  546. * returns zero on success, else negative errno.
  547. */
  548. static inline int
  549. usb_gadget_clear_selfpowered (struct usb_gadget *gadget)
  550. {
  551. if (!gadget->ops->set_selfpowered)
  552. return -EOPNOTSUPP;
  553. return gadget->ops->set_selfpowered (gadget, 0);
  554. }
  555. /**
  556. * usb_gadget_vbus_connect - Notify controller that VBUS is powered
  557. * @gadget:The device which now has VBUS power.
  558. *
  559. * This call is used by a driver for an external transceiver (or GPIO)
  560. * that detects a VBUS power session starting. Common responses include
  561. * resuming the controller, activating the D+ (or D-) pullup to let the
  562. * host detect that a USB device is attached, and starting to draw power
  563. * (8mA or possibly more, especially after SET_CONFIGURATION).
  564. *
  565. * Returns zero on success, else negative errno.
  566. */
  567. static inline int
  568. usb_gadget_vbus_connect(struct usb_gadget *gadget)
  569. {
  570. if (!gadget->ops->vbus_session)
  571. return -EOPNOTSUPP;
  572. return gadget->ops->vbus_session (gadget, 1);
  573. }
  574. /**
  575. * usb_gadget_vbus_draw - constrain controller's VBUS power usage
  576. * @gadget:The device whose VBUS usage is being described
  577. * @mA:How much current to draw, in milliAmperes. This should be twice
  578. * the value listed in the configuration descriptor bMaxPower field.
  579. *
  580. * This call is used by gadget drivers during SET_CONFIGURATION calls,
  581. * reporting how much power the device may consume. For example, this
  582. * could affect how quickly batteries are recharged.
  583. *
  584. * Returns zero on success, else negative errno.
  585. */
  586. static inline int
  587. usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
  588. {
  589. if (!gadget->ops->vbus_draw)
  590. return -EOPNOTSUPP;
  591. return gadget->ops->vbus_draw (gadget, mA);
  592. }
  593. /**
  594. * usb_gadget_vbus_disconnect - notify controller about VBUS session end
  595. * @gadget:the device whose VBUS supply is being described
  596. *
  597. * This call is used by a driver for an external transceiver (or GPIO)
  598. * that detects a VBUS power session ending. Common responses include
  599. * reversing everything done in usb_gadget_vbus_connect().
  600. *
  601. * Returns zero on success, else negative errno.
  602. */
  603. static inline int
  604. usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
  605. {
  606. if (!gadget->ops->vbus_session)
  607. return -EOPNOTSUPP;
  608. return gadget->ops->vbus_session (gadget, 0);
  609. }
  610. /**
  611. * usb_gadget_connect - software-controlled connect to USB host
  612. * @gadget:the peripheral being connected
  613. *
  614. * Enables the D+ (or potentially D-) pullup. The host will start
  615. * enumerating this gadget when the pullup is active and a VBUS session
  616. * is active (the link is powered). This pullup is always enabled unless
  617. * usb_gadget_disconnect() has been used to disable it.
  618. *
  619. * Returns zero on success, else negative errno.
  620. */
  621. static inline int
  622. usb_gadget_connect (struct usb_gadget *gadget)
  623. {
  624. if (!gadget->ops->pullup)
  625. return -EOPNOTSUPP;
  626. return gadget->ops->pullup (gadget, 1);
  627. }
  628. /**
  629. * usb_gadget_disconnect - software-controlled disconnect from USB host
  630. * @gadget:the peripheral being disconnected
  631. *
  632. * Disables the D+ (or potentially D-) pullup, which the host may see
  633. * as a disconnect (when a VBUS session is active). Not all systems
  634. * support software pullup controls.
  635. *
  636. * This routine may be used during the gadget driver bind() call to prevent
  637. * the peripheral from ever being visible to the USB host, unless later
  638. * usb_gadget_connect() is called. For example, user mode components may
  639. * need to be activated before the system can talk to hosts.
  640. *
  641. * Returns zero on success, else negative errno.
  642. */
  643. static inline int
  644. usb_gadget_disconnect (struct usb_gadget *gadget)
  645. {
  646. if (!gadget->ops->pullup)
  647. return -EOPNOTSUPP;
  648. return gadget->ops->pullup (gadget, 0);
  649. }
  650. /*-------------------------------------------------------------------------*/
  651. /**
  652. * struct usb_gadget_driver - driver for usb 'slave' devices
  653. * @function: String describing the gadget's function
  654. * @speed: Highest speed the driver handles.
  655. * @bind: Invoked when the driver is bound to a gadget, usually
  656. * after registering the driver.
  657. * At that point, ep0 is fully initialized, and ep_list holds
  658. * the currently-available endpoints.
  659. * Called in a context that permits sleeping.
  660. * @setup: Invoked for ep0 control requests that aren't handled by
  661. * the hardware level driver. Most calls must be handled by
  662. * the gadget driver, including descriptor and configuration
  663. * management. The 16 bit members of the setup data are in
  664. * USB byte order. Called in_interrupt; this may not sleep. Driver
  665. * queues a response to ep0, or returns negative to stall.
  666. * @disconnect: Invoked after all transfers have been stopped,
  667. * when the host is disconnected. May be called in_interrupt; this
  668. * may not sleep. Some devices can't detect disconnect, so this might
  669. * not be called except as part of controller shutdown.
  670. * @unbind: Invoked when the driver is unbound from a gadget,
  671. * usually from rmmod (after a disconnect is reported).
  672. * Called in a context that permits sleeping.
  673. * @suspend: Invoked on USB suspend. May be called in_interrupt.
  674. * @resume: Invoked on USB resume. May be called in_interrupt.
  675. * @driver: Driver model state for this driver.
  676. *
  677. * Devices are disabled till a gadget driver successfully bind()s, which
  678. * means the driver will handle setup() requests needed to enumerate (and
  679. * meet "chapter 9" requirements) then do some useful work.
  680. *
  681. * If gadget->is_otg is true, the gadget driver must provide an OTG
  682. * descriptor during enumeration, or else fail the bind() call. In such
  683. * cases, no USB traffic may flow until both bind() returns without
  684. * having called usb_gadget_disconnect(), and the USB host stack has
  685. * initialized.
  686. *
  687. * Drivers use hardware-specific knowledge to configure the usb hardware.
  688. * endpoint addressing is only one of several hardware characteristics that
  689. * are in descriptors the ep0 implementation returns from setup() calls.
  690. *
  691. * Except for ep0 implementation, most driver code shouldn't need change to
  692. * run on top of different usb controllers. It'll use endpoints set up by
  693. * that ep0 implementation.
  694. *
  695. * The usb controller driver handles a few standard usb requests. Those
  696. * include set_address, and feature flags for devices, interfaces, and
  697. * endpoints (the get_status, set_feature, and clear_feature requests).
  698. *
  699. * Accordingly, the driver's setup() callback must always implement all
  700. * get_descriptor requests, returning at least a device descriptor and
  701. * a configuration descriptor. Drivers must make sure the endpoint
  702. * descriptors match any hardware constraints. Some hardware also constrains
  703. * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
  704. *
  705. * The driver's setup() callback must also implement set_configuration,
  706. * and should also implement set_interface, get_configuration, and
  707. * get_interface. Setting a configuration (or interface) is where
  708. * endpoints should be activated or (config 0) shut down.
  709. *
  710. * (Note that only the default control endpoint is supported. Neither
  711. * hosts nor devices generally support control traffic except to ep0.)
  712. *
  713. * Most devices will ignore USB suspend/resume operations, and so will
  714. * not provide those callbacks. However, some may need to change modes
  715. * when the host is not longer directing those activities. For example,
  716. * local controls (buttons, dials, etc) may need to be re-enabled since
  717. * the (remote) host can't do that any longer; or an error state might
  718. * be cleared, to make the device behave identically whether or not
  719. * power is maintained.
  720. */
  721. struct usb_gadget_driver {
  722. char *function;
  723. enum usb_device_speed speed;
  724. int (*bind)(struct usb_gadget *);
  725. void (*unbind)(struct usb_gadget *);
  726. int (*setup)(struct usb_gadget *,
  727. const struct usb_ctrlrequest *);
  728. void (*disconnect)(struct usb_gadget *);
  729. void (*suspend)(struct usb_gadget *);
  730. void (*resume)(struct usb_gadget *);
  731. // FIXME support safe rmmod
  732. struct device_driver driver;
  733. };
  734. /*-------------------------------------------------------------------------*/
  735. /* driver modules register and unregister, as usual.
  736. * these calls must be made in a context that can sleep.
  737. *
  738. * these will usually be implemented directly by the hardware-dependent
  739. * usb bus interface driver, which will only support a single driver.
  740. */
  741. /**
  742. * usb_gadget_register_driver - register a gadget driver
  743. * @driver:the driver being registered
  744. *
  745. * Call this in your gadget driver's module initialization function,
  746. * to tell the underlying usb controller driver about your driver.
  747. * The driver's bind() function will be called to bind it to a
  748. * gadget before this registration call returns. It's expected that
  749. * the bind() functions will be in init sections.
  750. * This function must be called in a context that can sleep.
  751. */
  752. int usb_gadget_register_driver (struct usb_gadget_driver *driver);
  753. /**
  754. * usb_gadget_unregister_driver - unregister a gadget driver
  755. * @driver:the driver being unregistered
  756. *
  757. * Call this in your gadget driver's module cleanup function,
  758. * to tell the underlying usb controller that your driver is
  759. * going away. If the controller is connected to a USB host,
  760. * it will first disconnect(). The driver is also requested
  761. * to unbind() and clean up any device state, before this procedure
  762. * finally returns. It's expected that the unbind() functions
  763. * will in in exit sections, so may not be linked in some kernels.
  764. * This function must be called in a context that can sleep.
  765. */
  766. int usb_gadget_unregister_driver (struct usb_gadget_driver *driver);
  767. /*-------------------------------------------------------------------------*/
  768. /* utility to simplify dealing with string descriptors */
  769. /**
  770. * struct usb_string - wraps a C string and its USB id
  771. * @id:the (nonzero) ID for this string
  772. * @s:the string, in UTF-8 encoding
  773. *
  774. * If you're using usb_gadget_get_string(), use this to wrap a string
  775. * together with its ID.
  776. */
  777. struct usb_string {
  778. u8 id;
  779. const char *s;
  780. };
  781. /**
  782. * struct usb_gadget_strings - a set of USB strings in a given language
  783. * @language:identifies the strings' language (0x0409 for en-us)
  784. * @strings:array of strings with their ids
  785. *
  786. * If you're using usb_gadget_get_string(), use this to wrap all the
  787. * strings for a given language.
  788. */
  789. struct usb_gadget_strings {
  790. u16 language; /* 0x0409 for en-us */
  791. struct usb_string *strings;
  792. };
  793. /* put descriptor for string with that id into buf (buflen >= 256) */
  794. int usb_gadget_get_string (struct usb_gadget_strings *table, int id, u8 *buf);
  795. /*-------------------------------------------------------------------------*/
  796. /* utility to simplify managing config descriptors */
  797. /* write vector of descriptors into buffer */
  798. int usb_descriptor_fillbuf(void *, unsigned,
  799. const struct usb_descriptor_header **);
  800. /* build config descriptor from single descriptor vector */
  801. int usb_gadget_config_buf(const struct usb_config_descriptor *config,
  802. void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
  803. /*-------------------------------------------------------------------------*/
  804. /* utility wrapping a simple endpoint selection policy */
  805. extern struct usb_ep *usb_ep_autoconfig (struct usb_gadget *,
  806. struct usb_endpoint_descriptor *) __devinit;
  807. extern void usb_ep_autoconfig_reset (struct usb_gadget *) __devinit;
  808. #endif /* __KERNEL__ */
  809. #endif /* __LINUX_USB_GADGET_H */