gadget.h 38 KB

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  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. * Ported to U-Boot by: Thomas Smits <ts.smits@gmail.com> and
  15. * Remy Bohmer <linux@bohmer.net>
  16. */
  17. #ifndef __LINUX_USB_GADGET_H
  18. #define __LINUX_USB_GADGET_H
  19. #include <errno.h>
  20. #include <usb.h>
  21. #include <linux/compat.h>
  22. #include <linux/list.h>
  23. struct usb_ep;
  24. /**
  25. * struct usb_request - describes one i/o request
  26. * @buf: Buffer used for data. Always provide this; some controllers
  27. * only use PIO, or don't use DMA for some endpoints.
  28. * @dma: DMA address corresponding to 'buf'. If you don't set this
  29. * field, and the usb controller needs one, it is responsible
  30. * for mapping and unmapping the buffer.
  31. * @stream_id: The stream id, when USB3.0 bulk streams are being used
  32. * @length: Length of that data
  33. * @no_interrupt: If true, hints that no completion irq is needed.
  34. * Helpful sometimes with deep request queues that are handled
  35. * directly by DMA controllers.
  36. * @zero: If true, when writing data, makes the last packet be "short"
  37. * by adding a zero length packet as needed;
  38. * @short_not_ok: When reading data, makes short packets be
  39. * treated as errors (queue stops advancing till cleanup).
  40. * @complete: Function called when request completes, so this request and
  41. * its buffer may be re-used.
  42. * Reads terminate with a short packet, or when the buffer fills,
  43. * whichever comes first. When writes terminate, some data bytes
  44. * will usually still be in flight (often in a hardware fifo).
  45. * Errors (for reads or writes) stop the queue from advancing
  46. * until the completion function returns, so that any transfers
  47. * invalidated by the error may first be dequeued.
  48. * @context: For use by the completion callback
  49. * @list: For use by the gadget driver.
  50. * @status: Reports completion code, zero or a negative errno.
  51. * Normally, faults block the transfer queue from advancing until
  52. * the completion callback returns.
  53. * Code "-ESHUTDOWN" indicates completion caused by device disconnect,
  54. * or when the driver disabled the endpoint.
  55. * @actual: Reports bytes transferred to/from the buffer. For reads (OUT
  56. * transfers) this may be less than the requested length. If the
  57. * short_not_ok flag is set, short reads are treated as errors
  58. * even when status otherwise indicates successful completion.
  59. * Note that for writes (IN transfers) some data bytes may still
  60. * reside in a device-side FIFO when the request is reported as
  61. * complete.
  62. *
  63. * These are allocated/freed through the endpoint they're used with. The
  64. * hardware's driver can add extra per-request data to the memory it returns,
  65. * which often avoids separate memory allocations (potential failures),
  66. * later when the request is queued.
  67. *
  68. * Request flags affect request handling, such as whether a zero length
  69. * packet is written (the "zero" flag), whether a short read should be
  70. * treated as an error (blocking request queue advance, the "short_not_ok"
  71. * flag), or hinting that an interrupt is not required (the "no_interrupt"
  72. * flag, for use with deep request queues).
  73. *
  74. * Bulk endpoints can use any size buffers, and can also be used for interrupt
  75. * transfers. interrupt-only endpoints can be much less functional.
  76. *
  77. * NOTE: this is analagous to 'struct urb' on the host side, except that
  78. * it's thinner and promotes more pre-allocation.
  79. */
  80. struct usb_request {
  81. void *buf;
  82. unsigned length;
  83. dma_addr_t dma;
  84. unsigned stream_id:16;
  85. unsigned no_interrupt:1;
  86. unsigned zero:1;
  87. unsigned short_not_ok:1;
  88. void (*complete)(struct usb_ep *ep,
  89. struct usb_request *req);
  90. void *context;
  91. struct list_head list;
  92. int status;
  93. unsigned actual;
  94. };
  95. /*-------------------------------------------------------------------------*/
  96. /* endpoint-specific parts of the api to the usb controller hardware.
  97. * unlike the urb model, (de)multiplexing layers are not required.
  98. * (so this api could slash overhead if used on the host side...)
  99. *
  100. * note that device side usb controllers commonly differ in how many
  101. * endpoints they support, as well as their capabilities.
  102. */
  103. struct usb_ep_ops {
  104. int (*enable) (struct usb_ep *ep,
  105. const struct usb_endpoint_descriptor *desc);
  106. int (*disable) (struct usb_ep *ep);
  107. struct usb_request *(*alloc_request) (struct usb_ep *ep,
  108. gfp_t gfp_flags);
  109. void (*free_request) (struct usb_ep *ep, struct usb_request *req);
  110. int (*queue) (struct usb_ep *ep, struct usb_request *req,
  111. gfp_t gfp_flags);
  112. int (*dequeue) (struct usb_ep *ep, struct usb_request *req);
  113. int (*set_halt) (struct usb_ep *ep, int value);
  114. int (*set_wedge)(struct usb_ep *ep);
  115. int (*fifo_status) (struct usb_ep *ep);
  116. void (*fifo_flush) (struct usb_ep *ep);
  117. };
  118. /**
  119. * struct usb_ep_caps - endpoint capabilities description
  120. * @type_control:Endpoint supports control type (reserved for ep0).
  121. * @type_iso:Endpoint supports isochronous transfers.
  122. * @type_bulk:Endpoint supports bulk transfers.
  123. * @type_int:Endpoint supports interrupt transfers.
  124. * @dir_in:Endpoint supports IN direction.
  125. * @dir_out:Endpoint supports OUT direction.
  126. */
  127. struct usb_ep_caps {
  128. unsigned type_control:1;
  129. unsigned type_iso:1;
  130. unsigned type_bulk:1;
  131. unsigned type_int:1;
  132. unsigned dir_in:1;
  133. unsigned dir_out:1;
  134. };
  135. /**
  136. * struct usb_ep - device side representation of USB endpoint
  137. * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk"
  138. * @ops: Function pointers used to access hardware-specific operations.
  139. * @ep_list:the gadget's ep_list holds all of its endpoints
  140. * @caps:The structure describing types and directions supported by endoint.
  141. * @maxpacket:The maximum packet size used on this endpoint. The initial
  142. * value can sometimes be reduced (hardware allowing), according to
  143. * the endpoint descriptor used to configure the endpoint.
  144. * @maxpacket_limit:The maximum packet size value which can be handled by this
  145. * endpoint. It's set once by UDC driver when endpoint is initialized, and
  146. * should not be changed. Should not be confused with maxpacket.
  147. * @max_streams: The maximum number of streams supported
  148. * by this EP (0 - 16, actual number is 2^n)
  149. * @maxburst: the maximum number of bursts supported by this EP (for usb3)
  150. * @driver_data:for use by the gadget driver. all other fields are
  151. * read-only to gadget drivers.
  152. * @desc: endpoint descriptor. This pointer is set before the endpoint is
  153. * enabled and remains valid until the endpoint is disabled.
  154. * @comp_desc: In case of SuperSpeed support, this is the endpoint companion
  155. * descriptor that is used to configure the endpoint
  156. *
  157. * the bus controller driver lists all the general purpose endpoints in
  158. * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list,
  159. * and is accessed only in response to a driver setup() callback.
  160. */
  161. struct usb_ep {
  162. void *driver_data;
  163. const char *name;
  164. const struct usb_ep_ops *ops;
  165. struct list_head ep_list;
  166. struct usb_ep_caps caps;
  167. unsigned maxpacket:16;
  168. unsigned maxpacket_limit:16;
  169. unsigned max_streams:16;
  170. unsigned maxburst:5;
  171. const struct usb_endpoint_descriptor *desc;
  172. const struct usb_ss_ep_comp_descriptor *comp_desc;
  173. };
  174. /*-------------------------------------------------------------------------*/
  175. /**
  176. * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
  177. * @ep:the endpoint being configured
  178. * @maxpacket_limit:value of maximum packet size limit
  179. *
  180. * This function shoud be used only in UDC drivers to initialize endpoint
  181. * (usually in probe function).
  182. */
  183. static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
  184. unsigned maxpacket_limit)
  185. {
  186. ep->maxpacket_limit = maxpacket_limit;
  187. ep->maxpacket = maxpacket_limit;
  188. }
  189. /**
  190. * usb_ep_enable - configure endpoint, making it usable
  191. * @ep:the endpoint being configured. may not be the endpoint named "ep0".
  192. * drivers discover endpoints through the ep_list of a usb_gadget.
  193. * @desc:descriptor for desired behavior. caller guarantees this pointer
  194. * remains valid until the endpoint is disabled; the data byte order
  195. * is little-endian (usb-standard).
  196. *
  197. * when configurations are set, or when interface settings change, the driver
  198. * will enable or disable the relevant endpoints. while it is enabled, an
  199. * endpoint may be used for i/o until the driver receives a disconnect() from
  200. * the host or until the endpoint is disabled.
  201. *
  202. * the ep0 implementation (which calls this routine) must ensure that the
  203. * hardware capabilities of each endpoint match the descriptor provided
  204. * for it. for example, an endpoint named "ep2in-bulk" would be usable
  205. * for interrupt transfers as well as bulk, but it likely couldn't be used
  206. * for iso transfers or for endpoint 14. some endpoints are fully
  207. * configurable, with more generic names like "ep-a". (remember that for
  208. * USB, "in" means "towards the USB master".)
  209. *
  210. * returns zero, or a negative error code.
  211. */
  212. static inline int usb_ep_enable(struct usb_ep *ep,
  213. const struct usb_endpoint_descriptor *desc)
  214. {
  215. return ep->ops->enable(ep, desc);
  216. }
  217. /**
  218. * usb_ep_disable - endpoint is no longer usable
  219. * @ep:the endpoint being unconfigured. may not be the endpoint named "ep0".
  220. *
  221. * no other task may be using this endpoint when this is called.
  222. * any pending and uncompleted requests will complete with status
  223. * indicating disconnect (-ESHUTDOWN) before this call returns.
  224. * gadget drivers must call usb_ep_enable() again before queueing
  225. * requests to the endpoint.
  226. *
  227. * returns zero, or a negative error code.
  228. */
  229. static inline int usb_ep_disable(struct usb_ep *ep)
  230. {
  231. return ep->ops->disable(ep);
  232. }
  233. /**
  234. * usb_ep_alloc_request - allocate a request object to use with this endpoint
  235. * @ep:the endpoint to be used with with the request
  236. * @gfp_flags:GFP_* flags to use
  237. *
  238. * Request objects must be allocated with this call, since they normally
  239. * need controller-specific setup and may even need endpoint-specific
  240. * resources such as allocation of DMA descriptors.
  241. * Requests may be submitted with usb_ep_queue(), and receive a single
  242. * completion callback. Free requests with usb_ep_free_request(), when
  243. * they are no longer needed.
  244. *
  245. * Returns the request, or null if one could not be allocated.
  246. */
  247. static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
  248. gfp_t gfp_flags)
  249. {
  250. return ep->ops->alloc_request(ep, gfp_flags);
  251. }
  252. /**
  253. * usb_ep_free_request - frees a request object
  254. * @ep:the endpoint associated with the request
  255. * @req:the request being freed
  256. *
  257. * Reverses the effect of usb_ep_alloc_request().
  258. * Caller guarantees the request is not queued, and that it will
  259. * no longer be requeued (or otherwise used).
  260. */
  261. static inline void usb_ep_free_request(struct usb_ep *ep,
  262. struct usb_request *req)
  263. {
  264. ep->ops->free_request(ep, req);
  265. }
  266. /**
  267. * usb_ep_queue - queues (submits) an I/O request to an endpoint.
  268. * @ep:the endpoint associated with the request
  269. * @req:the request being submitted
  270. * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
  271. * pre-allocate all necessary memory with the request.
  272. *
  273. * This tells the device controller to perform the specified request through
  274. * that endpoint (reading or writing a buffer). When the request completes,
  275. * including being canceled by usb_ep_dequeue(), the request's completion
  276. * routine is called to return the request to the driver. Any endpoint
  277. * (except control endpoints like ep0) may have more than one transfer
  278. * request queued; they complete in FIFO order. Once a gadget driver
  279. * submits a request, that request may not be examined or modified until it
  280. * is given back to that driver through the completion callback.
  281. *
  282. * Each request is turned into one or more packets. The controller driver
  283. * never merges adjacent requests into the same packet. OUT transfers
  284. * will sometimes use data that's already buffered in the hardware.
  285. * Drivers can rely on the fact that the first byte of the request's buffer
  286. * always corresponds to the first byte of some USB packet, for both
  287. * IN and OUT transfers.
  288. *
  289. * Bulk endpoints can queue any amount of data; the transfer is packetized
  290. * automatically. The last packet will be short if the request doesn't fill it
  291. * out completely. Zero length packets (ZLPs) should be avoided in portable
  292. * protocols since not all usb hardware can successfully handle zero length
  293. * packets. (ZLPs may be explicitly written, and may be implicitly written if
  294. * the request 'zero' flag is set.) Bulk endpoints may also be used
  295. * for interrupt transfers; but the reverse is not true, and some endpoints
  296. * won't support every interrupt transfer. (Such as 768 byte packets.)
  297. *
  298. * Interrupt-only endpoints are less functional than bulk endpoints, for
  299. * example by not supporting queueing or not handling buffers that are
  300. * larger than the endpoint's maxpacket size. They may also treat data
  301. * toggle differently.
  302. *
  303. * Control endpoints ... after getting a setup() callback, the driver queues
  304. * one response (even if it would be zero length). That enables the
  305. * status ack, after transfering data as specified in the response. Setup
  306. * functions may return negative error codes to generate protocol stalls.
  307. * (Note that some USB device controllers disallow protocol stall responses
  308. * in some cases.) When control responses are deferred (the response is
  309. * written after the setup callback returns), then usb_ep_set_halt() may be
  310. * used on ep0 to trigger protocol stalls.
  311. *
  312. * For periodic endpoints, like interrupt or isochronous ones, the usb host
  313. * arranges to poll once per interval, and the gadget driver usually will
  314. * have queued some data to transfer at that time.
  315. *
  316. * Returns zero, or a negative error code. Endpoints that are not enabled
  317. * report errors; errors will also be
  318. * reported when the usb peripheral is disconnected.
  319. */
  320. static inline int usb_ep_queue(struct usb_ep *ep,
  321. struct usb_request *req, gfp_t gfp_flags)
  322. {
  323. return ep->ops->queue(ep, req, gfp_flags);
  324. }
  325. /**
  326. * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
  327. * @ep:the endpoint associated with the request
  328. * @req:the request being canceled
  329. *
  330. * if the request is still active on the endpoint, it is dequeued and its
  331. * completion routine is called (with status -ECONNRESET); else a negative
  332. * error code is returned.
  333. *
  334. * note that some hardware can't clear out write fifos (to unlink the request
  335. * at the head of the queue) except as part of disconnecting from usb. such
  336. * restrictions prevent drivers from supporting configuration changes,
  337. * even to configuration zero (a "chapter 9" requirement).
  338. */
  339. static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
  340. {
  341. return ep->ops->dequeue(ep, req);
  342. }
  343. /**
  344. * usb_ep_set_halt - sets the endpoint halt feature.
  345. * @ep: the non-isochronous endpoint being stalled
  346. *
  347. * Use this to stall an endpoint, perhaps as an error report.
  348. * Except for control endpoints,
  349. * the endpoint stays halted (will not stream any data) until the host
  350. * clears this feature; drivers may need to empty the endpoint's request
  351. * queue first, to make sure no inappropriate transfers happen.
  352. *
  353. * Note that while an endpoint CLEAR_FEATURE will be invisible to the
  354. * gadget driver, a SET_INTERFACE will not be. To reset endpoints for the
  355. * current altsetting, see usb_ep_clear_halt(). When switching altsettings,
  356. * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
  357. *
  358. * Returns zero, or a negative error code. On success, this call sets
  359. * underlying hardware state that blocks data transfers.
  360. * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
  361. * transfer requests are still queued, or if the controller hardware
  362. * (usually a FIFO) still holds bytes that the host hasn't collected.
  363. */
  364. static inline int usb_ep_set_halt(struct usb_ep *ep)
  365. {
  366. return ep->ops->set_halt(ep, 1);
  367. }
  368. /**
  369. * usb_ep_clear_halt - clears endpoint halt, and resets toggle
  370. * @ep:the bulk or interrupt endpoint being reset
  371. *
  372. * Use this when responding to the standard usb "set interface" request,
  373. * for endpoints that aren't reconfigured, after clearing any other state
  374. * in the endpoint's i/o queue.
  375. *
  376. * Returns zero, or a negative error code. On success, this call clears
  377. * the underlying hardware state reflecting endpoint halt and data toggle.
  378. * Note that some hardware can't support this request (like pxa2xx_udc),
  379. * and accordingly can't correctly implement interface altsettings.
  380. */
  381. static inline int usb_ep_clear_halt(struct usb_ep *ep)
  382. {
  383. return ep->ops->set_halt(ep, 0);
  384. }
  385. /**
  386. * usb_ep_fifo_status - returns number of bytes in fifo, or error
  387. * @ep: the endpoint whose fifo status is being checked.
  388. *
  389. * FIFO endpoints may have "unclaimed data" in them in certain cases,
  390. * such as after aborted transfers. Hosts may not have collected all
  391. * the IN data written by the gadget driver (and reported by a request
  392. * completion). The gadget driver may not have collected all the data
  393. * written OUT to it by the host. Drivers that need precise handling for
  394. * fault reporting or recovery may need to use this call.
  395. *
  396. * This returns the number of such bytes in the fifo, or a negative
  397. * errno if the endpoint doesn't use a FIFO or doesn't support such
  398. * precise handling.
  399. */
  400. static inline int usb_ep_fifo_status(struct usb_ep *ep)
  401. {
  402. if (ep->ops->fifo_status)
  403. return ep->ops->fifo_status(ep);
  404. else
  405. return -EOPNOTSUPP;
  406. }
  407. /**
  408. * usb_ep_fifo_flush - flushes contents of a fifo
  409. * @ep: the endpoint whose fifo is being flushed.
  410. *
  411. * This call may be used to flush the "unclaimed data" that may exist in
  412. * an endpoint fifo after abnormal transaction terminations. The call
  413. * must never be used except when endpoint is not being used for any
  414. * protocol translation.
  415. */
  416. static inline void usb_ep_fifo_flush(struct usb_ep *ep)
  417. {
  418. if (ep->ops->fifo_flush)
  419. ep->ops->fifo_flush(ep);
  420. }
  421. /*-------------------------------------------------------------------------*/
  422. struct usb_dcd_config_params {
  423. __u8 bU1devExitLat; /* U1 Device exit Latency */
  424. __le16 bU2DevExitLat; /* U2 Device exit Latency */
  425. };
  426. struct usb_gadget;
  427. struct usb_gadget_driver;
  428. /* the rest of the api to the controller hardware: device operations,
  429. * which don't involve endpoints (or i/o).
  430. */
  431. struct usb_gadget_ops {
  432. int (*get_frame)(struct usb_gadget *);
  433. int (*wakeup)(struct usb_gadget *);
  434. int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
  435. int (*vbus_session) (struct usb_gadget *, int is_active);
  436. int (*vbus_draw) (struct usb_gadget *, unsigned mA);
  437. int (*pullup) (struct usb_gadget *, int is_on);
  438. int (*ioctl)(struct usb_gadget *,
  439. unsigned code, unsigned long param);
  440. void (*get_config_params)(struct usb_dcd_config_params *);
  441. int (*udc_start)(struct usb_gadget *,
  442. struct usb_gadget_driver *);
  443. int (*udc_stop)(struct usb_gadget *);
  444. struct usb_ep *(*match_ep)(struct usb_gadget *,
  445. struct usb_endpoint_descriptor *,
  446. struct usb_ss_ep_comp_descriptor *);
  447. int (*ep_conf)(struct usb_gadget *,
  448. struct usb_ep *,
  449. struct usb_endpoint_descriptor *);
  450. void (*udc_set_speed)(struct usb_gadget *gadget,
  451. enum usb_device_speed);
  452. };
  453. /**
  454. * struct usb_gadget - represents a usb slave device
  455. * @ops: Function pointers used to access hardware-specific operations.
  456. * @ep0: Endpoint zero, used when reading or writing responses to
  457. * driver setup() requests
  458. * @ep_list: List of other endpoints supported by the device.
  459. * @speed: Speed of current connection to USB host.
  460. * @max_speed: Maximal speed the UDC can handle. UDC must support this
  461. * and all slower speeds.
  462. * @is_dualspeed: true if the controller supports both high and full speed
  463. * operation. If it does, the gadget driver must also support both.
  464. * @is_otg: true if the USB device port uses a Mini-AB jack, so that the
  465. * gadget driver must provide a USB OTG descriptor.
  466. * @is_a_peripheral: false unless is_otg, the "A" end of a USB cable
  467. * is in the Mini-AB jack, and HNP has been used to switch roles
  468. * so that the "A" device currently acts as A-Peripheral, not A-Host.
  469. * @a_hnp_support: OTG device feature flag, indicating that the A-Host
  470. * supports HNP at this port.
  471. * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
  472. * only supports HNP on a different root port.
  473. * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
  474. * enabled HNP support.
  475. * @name: Identifies the controller hardware type. Used in diagnostics
  476. * and sometimes configuration.
  477. * @dev: Driver model state for this abstract device.
  478. * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
  479. * MaxPacketSize.
  480. *
  481. * Gadgets have a mostly-portable "gadget driver" implementing device
  482. * functions, handling all usb configurations and interfaces. Gadget
  483. * drivers talk to hardware-specific code indirectly, through ops vectors.
  484. * That insulates the gadget driver from hardware details, and packages
  485. * the hardware endpoints through generic i/o queues. The "usb_gadget"
  486. * and "usb_ep" interfaces provide that insulation from the hardware.
  487. *
  488. * Except for the driver data, all fields in this structure are
  489. * read-only to the gadget driver. That driver data is part of the
  490. * "driver model" infrastructure in 2.6 (and later) kernels, and for
  491. * earlier systems is grouped in a similar structure that's not known
  492. * to the rest of the kernel.
  493. *
  494. * Values of the three OTG device feature flags are updated before the
  495. * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
  496. * driver suspend() calls. They are valid only when is_otg, and when the
  497. * device is acting as a B-Peripheral (so is_a_peripheral is false).
  498. */
  499. struct usb_gadget {
  500. /* readonly to gadget driver */
  501. const struct usb_gadget_ops *ops;
  502. struct usb_ep *ep0;
  503. struct list_head ep_list; /* of usb_ep */
  504. enum usb_device_speed speed;
  505. enum usb_device_speed max_speed;
  506. enum usb_device_state state;
  507. unsigned is_dualspeed:1;
  508. unsigned is_otg:1;
  509. unsigned is_a_peripheral:1;
  510. unsigned b_hnp_enable:1;
  511. unsigned a_hnp_support:1;
  512. unsigned a_alt_hnp_support:1;
  513. const char *name;
  514. struct device dev;
  515. unsigned quirk_ep_out_aligned_size:1;
  516. };
  517. static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
  518. {
  519. gadget->dev.driver_data = data;
  520. }
  521. static inline void *get_gadget_data(struct usb_gadget *gadget)
  522. {
  523. return gadget->dev.driver_data;
  524. }
  525. static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
  526. {
  527. return container_of(dev, struct usb_gadget, dev);
  528. }
  529. /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
  530. #define gadget_for_each_ep(tmp, gadget) \
  531. list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
  532. /**
  533. * gadget_is_dualspeed - return true iff the hardware handles high speed
  534. * @g: controller that might support both high and full speeds
  535. */
  536. static inline int gadget_is_dualspeed(struct usb_gadget *g)
  537. {
  538. #ifdef CONFIG_USB_GADGET_DUALSPEED
  539. /* runtime test would check "g->is_dualspeed" ... that might be
  540. * useful to work around hardware bugs, but is mostly pointless
  541. */
  542. return 1;
  543. #else
  544. return 0;
  545. #endif
  546. }
  547. /**
  548. * gadget_is_otg - return true iff the hardware is OTG-ready
  549. * @g: controller that might have a Mini-AB connector
  550. *
  551. * This is a runtime test, since kernels with a USB-OTG stack sometimes
  552. * run on boards which only have a Mini-B (or Mini-A) connector.
  553. */
  554. static inline int gadget_is_otg(struct usb_gadget *g)
  555. {
  556. #ifdef CONFIG_USB_OTG
  557. return g->is_otg;
  558. #else
  559. return 0;
  560. #endif
  561. }
  562. /**
  563. * gadget_is_superspeed() - return true if the hardware handles superspeed
  564. * @g: controller that might support superspeed
  565. */
  566. static inline int gadget_is_superspeed(struct usb_gadget *g)
  567. {
  568. return g->max_speed >= USB_SPEED_SUPER;
  569. }
  570. /**
  571. * usb_gadget_frame_number - returns the current frame number
  572. * @gadget: controller that reports the frame number
  573. *
  574. * Returns the usb frame number, normally eleven bits from a SOF packet,
  575. * or negative errno if this device doesn't support this capability.
  576. */
  577. static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
  578. {
  579. return gadget->ops->get_frame(gadget);
  580. }
  581. /**
  582. * usb_gadget_wakeup - tries to wake up the host connected to this gadget
  583. * @gadget: controller used to wake up the host
  584. *
  585. * Returns zero on success, else negative error code if the hardware
  586. * doesn't support such attempts, or its support has not been enabled
  587. * by the usb host. Drivers must return device descriptors that report
  588. * their ability to support this, or hosts won't enable it.
  589. *
  590. * This may also try to use SRP to wake the host and start enumeration,
  591. * even if OTG isn't otherwise in use. OTG devices may also start
  592. * remote wakeup even when hosts don't explicitly enable it.
  593. */
  594. static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
  595. {
  596. if (!gadget->ops->wakeup)
  597. return -EOPNOTSUPP;
  598. return gadget->ops->wakeup(gadget);
  599. }
  600. /**
  601. * usb_gadget_set_selfpowered - sets the device selfpowered feature.
  602. * @gadget:the device being declared as self-powered
  603. *
  604. * this affects the device status reported by the hardware driver
  605. * to reflect that it now has a local power supply.
  606. *
  607. * returns zero on success, else negative errno.
  608. */
  609. static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
  610. {
  611. if (!gadget->ops->set_selfpowered)
  612. return -EOPNOTSUPP;
  613. return gadget->ops->set_selfpowered(gadget, 1);
  614. }
  615. /**
  616. * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
  617. * @gadget:the device being declared as bus-powered
  618. *
  619. * this affects the device status reported by the hardware driver.
  620. * some hardware may not support bus-powered operation, in which
  621. * case this feature's value can never change.
  622. *
  623. * returns zero on success, else negative errno.
  624. */
  625. static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
  626. {
  627. if (!gadget->ops->set_selfpowered)
  628. return -EOPNOTSUPP;
  629. return gadget->ops->set_selfpowered(gadget, 0);
  630. }
  631. /**
  632. * usb_gadget_vbus_connect - Notify controller that VBUS is powered
  633. * @gadget:The device which now has VBUS power.
  634. *
  635. * This call is used by a driver for an external transceiver (or GPIO)
  636. * that detects a VBUS power session starting. Common responses include
  637. * resuming the controller, activating the D+ (or D-) pullup to let the
  638. * host detect that a USB device is attached, and starting to draw power
  639. * (8mA or possibly more, especially after SET_CONFIGURATION).
  640. *
  641. * Returns zero on success, else negative errno.
  642. */
  643. static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
  644. {
  645. if (!gadget->ops->vbus_session)
  646. return -EOPNOTSUPP;
  647. return gadget->ops->vbus_session(gadget, 1);
  648. }
  649. /**
  650. * usb_gadget_vbus_draw - constrain controller's VBUS power usage
  651. * @gadget:The device whose VBUS usage is being described
  652. * @mA:How much current to draw, in milliAmperes. This should be twice
  653. * the value listed in the configuration descriptor bMaxPower field.
  654. *
  655. * This call is used by gadget drivers during SET_CONFIGURATION calls,
  656. * reporting how much power the device may consume. For example, this
  657. * could affect how quickly batteries are recharged.
  658. *
  659. * Returns zero on success, else negative errno.
  660. */
  661. static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
  662. {
  663. if (!gadget->ops->vbus_draw)
  664. return -EOPNOTSUPP;
  665. return gadget->ops->vbus_draw(gadget, mA);
  666. }
  667. /**
  668. * usb_gadget_vbus_disconnect - notify controller about VBUS session end
  669. * @gadget:the device whose VBUS supply is being described
  670. *
  671. * This call is used by a driver for an external transceiver (or GPIO)
  672. * that detects a VBUS power session ending. Common responses include
  673. * reversing everything done in usb_gadget_vbus_connect().
  674. *
  675. * Returns zero on success, else negative errno.
  676. */
  677. static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
  678. {
  679. if (!gadget->ops->vbus_session)
  680. return -EOPNOTSUPP;
  681. return gadget->ops->vbus_session(gadget, 0);
  682. }
  683. /**
  684. * usb_gadget_connect - software-controlled connect to USB host
  685. * @gadget:the peripheral being connected
  686. *
  687. * Enables the D+ (or potentially D-) pullup. The host will start
  688. * enumerating this gadget when the pullup is active and a VBUS session
  689. * is active (the link is powered). This pullup is always enabled unless
  690. * usb_gadget_disconnect() has been used to disable it.
  691. *
  692. * Returns zero on success, else negative errno.
  693. */
  694. static inline int usb_gadget_connect(struct usb_gadget *gadget)
  695. {
  696. if (!gadget->ops->pullup)
  697. return -EOPNOTSUPP;
  698. return gadget->ops->pullup(gadget, 1);
  699. }
  700. /**
  701. * usb_gadget_disconnect - software-controlled disconnect from USB host
  702. * @gadget:the peripheral being disconnected
  703. *
  704. * Disables the D+ (or potentially D-) pullup, which the host may see
  705. * as a disconnect (when a VBUS session is active). Not all systems
  706. * support software pullup controls.
  707. *
  708. * This routine may be used during the gadget driver bind() call to prevent
  709. * the peripheral from ever being visible to the USB host, unless later
  710. * usb_gadget_connect() is called. For example, user mode components may
  711. * need to be activated before the system can talk to hosts.
  712. *
  713. * Returns zero on success, else negative errno.
  714. */
  715. static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
  716. {
  717. if (!gadget->ops->pullup)
  718. return -EOPNOTSUPP;
  719. return gadget->ops->pullup(gadget, 0);
  720. }
  721. /*-------------------------------------------------------------------------*/
  722. /**
  723. * struct usb_gadget_driver - driver for usb 'slave' devices
  724. * @function: String describing the gadget's function
  725. * @speed: Highest speed the driver handles.
  726. * @bind: Invoked when the driver is bound to a gadget, usually
  727. * after registering the driver.
  728. * At that point, ep0 is fully initialized, and ep_list holds
  729. * the currently-available endpoints.
  730. * Called in a context that permits sleeping.
  731. * @setup: Invoked for ep0 control requests that aren't handled by
  732. * the hardware level driver. Most calls must be handled by
  733. * the gadget driver, including descriptor and configuration
  734. * management. The 16 bit members of the setup data are in
  735. * USB byte order. Called in_interrupt; this may not sleep. Driver
  736. * queues a response to ep0, or returns negative to stall.
  737. * @disconnect: Invoked after all transfers have been stopped,
  738. * when the host is disconnected. May be called in_interrupt; this
  739. * may not sleep. Some devices can't detect disconnect, so this might
  740. * not be called except as part of controller shutdown.
  741. * @unbind: Invoked when the driver is unbound from a gadget,
  742. * usually from rmmod (after a disconnect is reported).
  743. * Called in a context that permits sleeping.
  744. * @suspend: Invoked on USB suspend. May be called in_interrupt.
  745. * @resume: Invoked on USB resume. May be called in_interrupt.
  746. * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers
  747. * and should be called in_interrupt.
  748. *
  749. * Devices are disabled till a gadget driver successfully bind()s, which
  750. * means the driver will handle setup() requests needed to enumerate (and
  751. * meet "chapter 9" requirements) then do some useful work.
  752. *
  753. * If gadget->is_otg is true, the gadget driver must provide an OTG
  754. * descriptor during enumeration, or else fail the bind() call. In such
  755. * cases, no USB traffic may flow until both bind() returns without
  756. * having called usb_gadget_disconnect(), and the USB host stack has
  757. * initialized.
  758. *
  759. * Drivers use hardware-specific knowledge to configure the usb hardware.
  760. * endpoint addressing is only one of several hardware characteristics that
  761. * are in descriptors the ep0 implementation returns from setup() calls.
  762. *
  763. * Except for ep0 implementation, most driver code shouldn't need change to
  764. * run on top of different usb controllers. It'll use endpoints set up by
  765. * that ep0 implementation.
  766. *
  767. * The usb controller driver handles a few standard usb requests. Those
  768. * include set_address, and feature flags for devices, interfaces, and
  769. * endpoints (the get_status, set_feature, and clear_feature requests).
  770. *
  771. * Accordingly, the driver's setup() callback must always implement all
  772. * get_descriptor requests, returning at least a device descriptor and
  773. * a configuration descriptor. Drivers must make sure the endpoint
  774. * descriptors match any hardware constraints. Some hardware also constrains
  775. * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
  776. *
  777. * The driver's setup() callback must also implement set_configuration,
  778. * and should also implement set_interface, get_configuration, and
  779. * get_interface. Setting a configuration (or interface) is where
  780. * endpoints should be activated or (config 0) shut down.
  781. *
  782. * (Note that only the default control endpoint is supported. Neither
  783. * hosts nor devices generally support control traffic except to ep0.)
  784. *
  785. * Most devices will ignore USB suspend/resume operations, and so will
  786. * not provide those callbacks. However, some may need to change modes
  787. * when the host is not longer directing those activities. For example,
  788. * local controls (buttons, dials, etc) may need to be re-enabled since
  789. * the (remote) host can't do that any longer; or an error state might
  790. * be cleared, to make the device behave identically whether or not
  791. * power is maintained.
  792. */
  793. struct usb_gadget_driver {
  794. char *function;
  795. enum usb_device_speed speed;
  796. int (*bind)(struct usb_gadget *);
  797. void (*unbind)(struct usb_gadget *);
  798. int (*setup)(struct usb_gadget *,
  799. const struct usb_ctrlrequest *);
  800. void (*disconnect)(struct usb_gadget *);
  801. void (*suspend)(struct usb_gadget *);
  802. void (*resume)(struct usb_gadget *);
  803. void (*reset)(struct usb_gadget *);
  804. };
  805. /*-------------------------------------------------------------------------*/
  806. /* driver modules register and unregister, as usual.
  807. * these calls must be made in a context that can sleep.
  808. *
  809. * these will usually be implemented directly by the hardware-dependent
  810. * usb bus interface driver, which will only support a single driver.
  811. */
  812. /**
  813. * usb_gadget_register_driver - register a gadget driver
  814. * @driver:the driver being registered
  815. *
  816. * Call this in your gadget driver's module initialization function,
  817. * to tell the underlying usb controller driver about your driver.
  818. * The driver's bind() function will be called to bind it to a
  819. * gadget before this registration call returns. It's expected that
  820. * the bind() functions will be in init sections.
  821. * This function must be called in a context that can sleep.
  822. */
  823. int usb_gadget_register_driver(struct usb_gadget_driver *driver);
  824. /**
  825. * usb_gadget_unregister_driver - unregister a gadget driver
  826. * @driver:the driver being unregistered
  827. *
  828. * Call this in your gadget driver's module cleanup function,
  829. * to tell the underlying usb controller that your driver is
  830. * going away. If the controller is connected to a USB host,
  831. * it will first disconnect(). The driver is also requested
  832. * to unbind() and clean up any device state, before this procedure
  833. * finally returns. It's expected that the unbind() functions
  834. * will in in exit sections, so may not be linked in some kernels.
  835. * This function must be called in a context that can sleep.
  836. */
  837. int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
  838. int usb_add_gadget_udc_release(struct device *parent,
  839. struct usb_gadget *gadget, void (*release)(struct device *dev));
  840. int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
  841. void usb_del_gadget_udc(struct usb_gadget *gadget);
  842. /*-------------------------------------------------------------------------*/
  843. /* utility to simplify dealing with string descriptors */
  844. /**
  845. * struct usb_gadget_strings - a set of USB strings in a given language
  846. * @language:identifies the strings' language (0x0409 for en-us)
  847. * @strings:array of strings with their ids
  848. *
  849. * If you're using usb_gadget_get_string(), use this to wrap all the
  850. * strings for a given language.
  851. */
  852. struct usb_gadget_strings {
  853. u16 language; /* 0x0409 for en-us */
  854. struct usb_string *strings;
  855. };
  856. /* put descriptor for string with that id into buf (buflen >= 256) */
  857. int usb_gadget_get_string(struct usb_gadget_strings *table, int id, u8 *buf);
  858. /*-------------------------------------------------------------------------*/
  859. /* utility to simplify managing config descriptors */
  860. /* write vector of descriptors into buffer */
  861. int usb_descriptor_fillbuf(void *, unsigned,
  862. const struct usb_descriptor_header **);
  863. /* build config descriptor from single descriptor vector */
  864. int usb_gadget_config_buf(const struct usb_config_descriptor *config,
  865. void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
  866. /*-------------------------------------------------------------------------*/
  867. /* utility to simplify map/unmap of usb_requests to/from DMA */
  868. extern int usb_gadget_map_request(struct usb_gadget *gadget,
  869. struct usb_request *req, int is_in);
  870. extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
  871. struct usb_request *req, int is_in);
  872. /*-------------------------------------------------------------------------*/
  873. /* utility to set gadget state properly */
  874. extern void usb_gadget_set_state(struct usb_gadget *gadget,
  875. enum usb_device_state state);
  876. /*-------------------------------------------------------------------------*/
  877. /* utility to tell udc core that the bus reset occurs */
  878. extern void usb_gadget_udc_reset(struct usb_gadget *gadget,
  879. struct usb_gadget_driver *driver);
  880. /*-------------------------------------------------------------------------*/
  881. /* utility to give requests back to the gadget layer */
  882. extern void usb_gadget_giveback_request(struct usb_ep *ep,
  883. struct usb_request *req);
  884. /*-------------------------------------------------------------------------*/
  885. /* utility wrapping a simple endpoint selection policy */
  886. extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
  887. struct usb_endpoint_descriptor *);
  888. extern void usb_ep_autoconfig_reset(struct usb_gadget *);
  889. extern int usb_gadget_handle_interrupts(int index);
  890. #if CONFIG_IS_ENABLED(DM_USB_GADGET)
  891. int usb_gadget_initialize(int index);
  892. int usb_gadget_release(int index);
  893. int dm_usb_gadget_handle_interrupts(struct udevice *dev);
  894. #else
  895. #include <usb.h>
  896. static inline int usb_gadget_initialize(int index)
  897. {
  898. return board_usb_init(index, USB_INIT_DEVICE);
  899. }
  900. static inline int usb_gadget_release(int index)
  901. {
  902. return board_usb_cleanup(index, USB_INIT_DEVICE);
  903. }
  904. #endif
  905. #endif /* __LINUX_USB_GADGET_H */