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 18 #ifndef __LINUX_USB_GADGET_H 19 #define __LINUX_USB_GADGET_H 20 21 #include <errno.h> 22 #include <usb.h> 23 #include <linux/compat.h> 24 #include <linux/list.h> 25 26 struct usb_ep; 27 28 /** 29 * struct usb_request - describes one i/o request 30 * @buf: Buffer used for data. Always provide this; some controllers 31 * only use PIO, or don't use DMA for some endpoints. 32 * @dma: DMA address corresponding to 'buf'. If you don't set this 33 * field, and the usb controller needs one, it is responsible 34 * for mapping and unmapping the buffer. 35 * @stream_id: The stream id, when USB3.0 bulk streams are being used 36 * @length: Length of that data 37 * @no_interrupt: If true, hints that no completion irq is needed. 38 * Helpful sometimes with deep request queues that are handled 39 * directly by DMA controllers. 40 * @zero: If true, when writing data, makes the last packet be "short" 41 * by adding a zero length packet as needed; 42 * @short_not_ok: When reading data, makes short packets be 43 * treated as errors (queue stops advancing till cleanup). 44 * @complete: Function called when request completes, so this request and 45 * its buffer may be re-used. 46 * Reads terminate with a short packet, or when the buffer fills, 47 * whichever comes first. When writes terminate, some data bytes 48 * will usually still be in flight (often in a hardware fifo). 49 * Errors (for reads or writes) stop the queue from advancing 50 * until the completion function returns, so that any transfers 51 * invalidated by the error may first be dequeued. 52 * @context: For use by the completion callback 53 * @list: For use by the gadget driver. 54 * @status: Reports completion code, zero or a negative errno. 55 * Normally, faults block the transfer queue from advancing until 56 * the completion callback returns. 57 * Code "-ESHUTDOWN" indicates completion caused by device disconnect, 58 * or when the driver disabled the endpoint. 59 * @actual: Reports bytes transferred to/from the buffer. For reads (OUT 60 * transfers) this may be less than the requested length. If the 61 * short_not_ok flag is set, short reads are treated as errors 62 * even when status otherwise indicates successful completion. 63 * Note that for writes (IN transfers) some data bytes may still 64 * reside in a device-side FIFO when the request is reported as 65 * complete. 66 * 67 * These are allocated/freed through the endpoint they're used with. The 68 * hardware's driver can add extra per-request data to the memory it returns, 69 * which often avoids separate memory allocations (potential failures), 70 * later when the request is queued. 71 * 72 * Request flags affect request handling, such as whether a zero length 73 * packet is written (the "zero" flag), whether a short read should be 74 * treated as an error (blocking request queue advance, the "short_not_ok" 75 * flag), or hinting that an interrupt is not required (the "no_interrupt" 76 * flag, for use with deep request queues). 77 * 78 * Bulk endpoints can use any size buffers, and can also be used for interrupt 79 * transfers. interrupt-only endpoints can be much less functional. 80 * 81 * NOTE: this is analagous to 'struct urb' on the host side, except that 82 * it's thinner and promotes more pre-allocation. 83 */ 84 85 struct usb_request { 86 void *buf; 87 unsigned length; 88 dma_addr_t dma; 89 90 unsigned stream_id:16; 91 unsigned no_interrupt:1; 92 unsigned zero:1; 93 unsigned short_not_ok:1; 94 95 void (*complete)(struct usb_ep *ep, 96 struct usb_request *req); 97 void *context; 98 struct list_head list; 99 100 int status; 101 unsigned actual; 102 }; 103 104 /*-------------------------------------------------------------------------*/ 105 106 /* endpoint-specific parts of the api to the usb controller hardware. 107 * unlike the urb model, (de)multiplexing layers are not required. 108 * (so this api could slash overhead if used on the host side...) 109 * 110 * note that device side usb controllers commonly differ in how many 111 * endpoints they support, as well as their capabilities. 112 */ 113 struct usb_ep_ops { 114 int (*enable) (struct usb_ep *ep, 115 const struct usb_endpoint_descriptor *desc); 116 int (*disable) (struct usb_ep *ep); 117 118 struct usb_request *(*alloc_request) (struct usb_ep *ep, 119 gfp_t gfp_flags); 120 void (*free_request) (struct usb_ep *ep, struct usb_request *req); 121 122 int (*queue) (struct usb_ep *ep, struct usb_request *req, 123 gfp_t gfp_flags); 124 int (*dequeue) (struct usb_ep *ep, struct usb_request *req); 125 126 int (*set_halt) (struct usb_ep *ep, int value); 127 int (*set_wedge)(struct usb_ep *ep); 128 int (*fifo_status) (struct usb_ep *ep); 129 void (*fifo_flush) (struct usb_ep *ep); 130 }; 131 132 /** 133 * struct usb_ep - device side representation of USB endpoint 134 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk" 135 * @ops: Function pointers used to access hardware-specific operations. 136 * @ep_list:the gadget's ep_list holds all of its endpoints 137 * @maxpacket:The maximum packet size used on this endpoint. The initial 138 * value can sometimes be reduced (hardware allowing), according to 139 * the endpoint descriptor used to configure the endpoint. 140 * @maxpacket_limit:The maximum packet size value which can be handled by this 141 * endpoint. It's set once by UDC driver when endpoint is initialized, and 142 * should not be changed. Should not be confused with maxpacket. 143 * @max_streams: The maximum number of streams supported 144 * by this EP (0 - 16, actual number is 2^n) 145 * @maxburst: the maximum number of bursts supported by this EP (for usb3) 146 * @driver_data:for use by the gadget driver. all other fields are 147 * read-only to gadget drivers. 148 * @desc: endpoint descriptor. This pointer is set before the endpoint is 149 * enabled and remains valid until the endpoint is disabled. 150 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion 151 * descriptor that is used to configure the endpoint 152 * 153 * the bus controller driver lists all the general purpose endpoints in 154 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list, 155 * and is accessed only in response to a driver setup() callback. 156 */ 157 struct usb_ep { 158 void *driver_data; 159 const char *name; 160 const struct usb_ep_ops *ops; 161 struct list_head ep_list; 162 unsigned maxpacket:16; 163 unsigned maxpacket_limit:16; 164 unsigned max_streams:16; 165 unsigned maxburst:5; 166 const struct usb_endpoint_descriptor *desc; 167 const struct usb_ss_ep_comp_descriptor *comp_desc; 168 }; 169 170 /*-------------------------------------------------------------------------*/ 171 172 /** 173 * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint 174 * @ep:the endpoint being configured 175 * @maxpacket_limit:value of maximum packet size limit 176 * 177 * This function shoud be used only in UDC drivers to initialize endpoint 178 * (usually in probe function). 179 */ 180 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep, 181 unsigned maxpacket_limit) 182 { 183 ep->maxpacket_limit = maxpacket_limit; 184 ep->maxpacket = maxpacket_limit; 185 } 186 187 /** 188 * usb_ep_enable - configure endpoint, making it usable 189 * @ep:the endpoint being configured. may not be the endpoint named "ep0". 190 * drivers discover endpoints through the ep_list of a usb_gadget. 191 * @desc:descriptor for desired behavior. caller guarantees this pointer 192 * remains valid until the endpoint is disabled; the data byte order 193 * is little-endian (usb-standard). 194 * 195 * when configurations are set, or when interface settings change, the driver 196 * will enable or disable the relevant endpoints. while it is enabled, an 197 * endpoint may be used for i/o until the driver receives a disconnect() from 198 * the host or until the endpoint is disabled. 199 * 200 * the ep0 implementation (which calls this routine) must ensure that the 201 * hardware capabilities of each endpoint match the descriptor provided 202 * for it. for example, an endpoint named "ep2in-bulk" would be usable 203 * for interrupt transfers as well as bulk, but it likely couldn't be used 204 * for iso transfers or for endpoint 14. some endpoints are fully 205 * configurable, with more generic names like "ep-a". (remember that for 206 * USB, "in" means "towards the USB master".) 207 * 208 * returns zero, or a negative error code. 209 */ 210 static inline int usb_ep_enable(struct usb_ep *ep, 211 const struct usb_endpoint_descriptor *desc) 212 { 213 return ep->ops->enable(ep, desc); 214 } 215 216 /** 217 * usb_ep_disable - endpoint is no longer usable 218 * @ep:the endpoint being unconfigured. may not be the endpoint named "ep0". 219 * 220 * no other task may be using this endpoint when this is called. 221 * any pending and uncompleted requests will complete with status 222 * indicating disconnect (-ESHUTDOWN) before this call returns. 223 * gadget drivers must call usb_ep_enable() again before queueing 224 * requests to the endpoint. 225 * 226 * returns zero, or a negative error code. 227 */ 228 static inline int usb_ep_disable(struct usb_ep *ep) 229 { 230 return ep->ops->disable(ep); 231 } 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 /** 254 * usb_ep_free_request - frees a request object 255 * @ep:the endpoint associated with the request 256 * @req:the request being freed 257 * 258 * Reverses the effect of usb_ep_alloc_request(). 259 * Caller guarantees the request is not queued, and that it will 260 * no longer be requeued (or otherwise used). 261 */ 262 static inline void usb_ep_free_request(struct usb_ep *ep, 263 struct usb_request *req) 264 { 265 ep->ops->free_request(ep, req); 266 } 267 268 /** 269 * usb_ep_queue - queues (submits) an I/O request to an endpoint. 270 * @ep:the endpoint associated with the request 271 * @req:the request being submitted 272 * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't 273 * pre-allocate all necessary memory with the request. 274 * 275 * This tells the device controller to perform the specified request through 276 * that endpoint (reading or writing a buffer). When the request completes, 277 * including being canceled by usb_ep_dequeue(), the request's completion 278 * routine is called to return the request to the driver. Any endpoint 279 * (except control endpoints like ep0) may have more than one transfer 280 * request queued; they complete in FIFO order. Once a gadget driver 281 * submits a request, that request may not be examined or modified until it 282 * is given back to that driver through the completion callback. 283 * 284 * Each request is turned into one or more packets. The controller driver 285 * never merges adjacent requests into the same packet. OUT transfers 286 * will sometimes use data that's already buffered in the hardware. 287 * Drivers can rely on the fact that the first byte of the request's buffer 288 * always corresponds to the first byte of some USB packet, for both 289 * IN and OUT transfers. 290 * 291 * Bulk endpoints can queue any amount of data; the transfer is packetized 292 * automatically. The last packet will be short if the request doesn't fill it 293 * out completely. Zero length packets (ZLPs) should be avoided in portable 294 * protocols since not all usb hardware can successfully handle zero length 295 * packets. (ZLPs may be explicitly written, and may be implicitly written if 296 * the request 'zero' flag is set.) Bulk endpoints may also be used 297 * for interrupt transfers; but the reverse is not true, and some endpoints 298 * won't support every interrupt transfer. (Such as 768 byte packets.) 299 * 300 * Interrupt-only endpoints are less functional than bulk endpoints, for 301 * example by not supporting queueing or not handling buffers that are 302 * larger than the endpoint's maxpacket size. They may also treat data 303 * toggle differently. 304 * 305 * Control endpoints ... after getting a setup() callback, the driver queues 306 * one response (even if it would be zero length). That enables the 307 * status ack, after transfering data as specified in the response. Setup 308 * functions may return negative error codes to generate protocol stalls. 309 * (Note that some USB device controllers disallow protocol stall responses 310 * in some cases.) When control responses are deferred (the response is 311 * written after the setup callback returns), then usb_ep_set_halt() may be 312 * used on ep0 to trigger protocol stalls. 313 * 314 * For periodic endpoints, like interrupt or isochronous ones, the usb host 315 * arranges to poll once per interval, and the gadget driver usually will 316 * have queued some data to transfer at that time. 317 * 318 * Returns zero, or a negative error code. Endpoints that are not enabled 319 * report errors; errors will also be 320 * reported when the usb peripheral is disconnected. 321 */ 322 static inline int usb_ep_queue(struct usb_ep *ep, 323 struct usb_request *req, gfp_t gfp_flags) 324 { 325 return ep->ops->queue(ep, req, gfp_flags); 326 } 327 328 /** 329 * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint 330 * @ep:the endpoint associated with the request 331 * @req:the request being canceled 332 * 333 * if the request is still active on the endpoint, it is dequeued and its 334 * completion routine is called (with status -ECONNRESET); else a negative 335 * error code is returned. 336 * 337 * note that some hardware can't clear out write fifos (to unlink the request 338 * at the head of the queue) except as part of disconnecting from usb. such 339 * restrictions prevent drivers from supporting configuration changes, 340 * even to configuration zero (a "chapter 9" requirement). 341 */ 342 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req) 343 { 344 return ep->ops->dequeue(ep, req); 345 } 346 347 /** 348 * usb_ep_set_halt - sets the endpoint halt feature. 349 * @ep: the non-isochronous endpoint being stalled 350 * 351 * Use this to stall an endpoint, perhaps as an error report. 352 * Except for control endpoints, 353 * the endpoint stays halted (will not stream any data) until the host 354 * clears this feature; drivers may need to empty the endpoint's request 355 * queue first, to make sure no inappropriate transfers happen. 356 * 357 * Note that while an endpoint CLEAR_FEATURE will be invisible to the 358 * gadget driver, a SET_INTERFACE will not be. To reset endpoints for the 359 * current altsetting, see usb_ep_clear_halt(). When switching altsettings, 360 * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints. 361 * 362 * Returns zero, or a negative error code. On success, this call sets 363 * underlying hardware state that blocks data transfers. 364 * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any 365 * transfer requests are still queued, or if the controller hardware 366 * (usually a FIFO) still holds bytes that the host hasn't collected. 367 */ 368 static inline int usb_ep_set_halt(struct usb_ep *ep) 369 { 370 return ep->ops->set_halt(ep, 1); 371 } 372 373 /** 374 * usb_ep_clear_halt - clears endpoint halt, and resets toggle 375 * @ep:the bulk or interrupt endpoint being reset 376 * 377 * Use this when responding to the standard usb "set interface" request, 378 * for endpoints that aren't reconfigured, after clearing any other state 379 * in the endpoint's i/o queue. 380 * 381 * Returns zero, or a negative error code. On success, this call clears 382 * the underlying hardware state reflecting endpoint halt and data toggle. 383 * Note that some hardware can't support this request (like pxa2xx_udc), 384 * and accordingly can't correctly implement interface altsettings. 385 */ 386 static inline int usb_ep_clear_halt(struct usb_ep *ep) 387 { 388 return ep->ops->set_halt(ep, 0); 389 } 390 391 /** 392 * usb_ep_fifo_status - returns number of bytes in fifo, or error 393 * @ep: the endpoint whose fifo status is being checked. 394 * 395 * FIFO endpoints may have "unclaimed data" in them in certain cases, 396 * such as after aborted transfers. Hosts may not have collected all 397 * the IN data written by the gadget driver (and reported by a request 398 * completion). The gadget driver may not have collected all the data 399 * written OUT to it by the host. Drivers that need precise handling for 400 * fault reporting or recovery may need to use this call. 401 * 402 * This returns the number of such bytes in the fifo, or a negative 403 * errno if the endpoint doesn't use a FIFO or doesn't support such 404 * precise handling. 405 */ 406 static inline int usb_ep_fifo_status(struct usb_ep *ep) 407 { 408 if (ep->ops->fifo_status) 409 return ep->ops->fifo_status(ep); 410 else 411 return -EOPNOTSUPP; 412 } 413 414 /** 415 * usb_ep_fifo_flush - flushes contents of a fifo 416 * @ep: the endpoint whose fifo is being flushed. 417 * 418 * This call may be used to flush the "unclaimed data" that may exist in 419 * an endpoint fifo after abnormal transaction terminations. The call 420 * must never be used except when endpoint is not being used for any 421 * protocol translation. 422 */ 423 static inline void usb_ep_fifo_flush(struct usb_ep *ep) 424 { 425 if (ep->ops->fifo_flush) 426 ep->ops->fifo_flush(ep); 427 } 428 429 430 /*-------------------------------------------------------------------------*/ 431 #define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */ 432 #define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */ 433 434 struct usb_gadget; 435 struct usb_gadget_driver; 436 437 /* the rest of the api to the controller hardware: device operations, 438 * which don't involve endpoints (or i/o). 439 */ 440 struct usb_gadget_ops { 441 int (*get_frame)(struct usb_gadget *); 442 int (*wakeup)(struct usb_gadget *); 443 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered); 444 int (*vbus_session) (struct usb_gadget *, int is_active); 445 int (*vbus_draw) (struct usb_gadget *, unsigned mA); 446 int (*pullup) (struct usb_gadget *, int is_on); 447 int (*ioctl)(struct usb_gadget *, 448 unsigned code, unsigned long param); 449 int (*udc_start)(struct usb_gadget *, 450 struct usb_gadget_driver *); 451 int (*udc_stop)(struct usb_gadget *); 452 }; 453 454 /** 455 * struct usb_gadget - represents a usb slave device 456 * @ops: Function pointers used to access hardware-specific operations. 457 * @ep0: Endpoint zero, used when reading or writing responses to 458 * driver setup() requests 459 * @ep_list: List of other endpoints supported by the device. 460 * @speed: Speed of current connection to USB host. 461 * @max_speed: Maximal speed the UDC can handle. UDC must support this 462 * and all slower speeds. 463 * @is_dualspeed: true if the controller supports both high and full speed 464 * operation. If it does, the gadget driver must also support both. 465 * @is_otg: true if the USB device port uses a Mini-AB jack, so that the 466 * gadget driver must provide a USB OTG descriptor. 467 * @is_a_peripheral: false unless is_otg, the "A" end of a USB cable 468 * is in the Mini-AB jack, and HNP has been used to switch roles 469 * so that the "A" device currently acts as A-Peripheral, not A-Host. 470 * @a_hnp_support: OTG device feature flag, indicating that the A-Host 471 * supports HNP at this port. 472 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host 473 * only supports HNP on a different root port. 474 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host 475 * enabled HNP support. 476 * @name: Identifies the controller hardware type. Used in diagnostics 477 * and sometimes configuration. 478 * @dev: Driver model state for this abstract device. 479 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to 480 * MaxPacketSize. 481 * 482 * Gadgets have a mostly-portable "gadget driver" implementing device 483 * functions, handling all usb configurations and interfaces. Gadget 484 * drivers talk to hardware-specific code indirectly, through ops vectors. 485 * That insulates the gadget driver from hardware details, and packages 486 * the hardware endpoints through generic i/o queues. The "usb_gadget" 487 * and "usb_ep" interfaces provide that insulation from the hardware. 488 * 489 * Except for the driver data, all fields in this structure are 490 * read-only to the gadget driver. That driver data is part of the 491 * "driver model" infrastructure in 2.6 (and later) kernels, and for 492 * earlier systems is grouped in a similar structure that's not known 493 * to the rest of the kernel. 494 * 495 * Values of the three OTG device feature flags are updated before the 496 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before 497 * driver suspend() calls. They are valid only when is_otg, and when the 498 * device is acting as a B-Peripheral (so is_a_peripheral is false). 499 */ 500 struct usb_gadget { 501 /* readonly to gadget driver */ 502 const struct usb_gadget_ops *ops; 503 struct usb_ep *ep0; 504 struct list_head ep_list; /* of usb_ep */ 505 enum usb_device_speed speed; 506 enum usb_device_speed max_speed; 507 enum usb_device_state state; 508 unsigned is_dualspeed:1; 509 unsigned is_otg:1; 510 unsigned is_a_peripheral:1; 511 unsigned b_hnp_enable:1; 512 unsigned a_hnp_support:1; 513 unsigned a_alt_hnp_support:1; 514 const char *name; 515 struct device dev; 516 unsigned quirk_ep_out_aligned_size:1; 517 }; 518 519 static inline void set_gadget_data(struct usb_gadget *gadget, void *data) 520 { 521 gadget->dev.driver_data = data; 522 } 523 524 static inline void *get_gadget_data(struct usb_gadget *gadget) 525 { 526 return gadget->dev.driver_data; 527 } 528 529 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev) 530 { 531 return container_of(dev, struct usb_gadget, dev); 532 } 533 534 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */ 535 #define gadget_for_each_ep(tmp, gadget) \ 536 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list) 537 538 539 /** 540 * gadget_is_dualspeed - return true iff the hardware handles high speed 541 * @g: controller that might support both high and full speeds 542 */ 543 static inline int gadget_is_dualspeed(struct usb_gadget *g) 544 { 545 #ifdef CONFIG_USB_GADGET_DUALSPEED 546 /* runtime test would check "g->is_dualspeed" ... that might be 547 * useful to work around hardware bugs, but is mostly pointless 548 */ 549 return 1; 550 #else 551 return 0; 552 #endif 553 } 554 555 /** 556 * gadget_is_superspeed() - return true if the hardware handles superspeed 557 * @g: controller that might support superspeed 558 */ 559 static inline int gadget_is_superspeed(struct usb_gadget *g) 560 { 561 return g->max_speed >= USB_SPEED_SUPER; 562 } 563 564 /** 565 * gadget_is_otg - return true iff the hardware is OTG-ready 566 * @g: controller that might have a Mini-AB connector 567 * 568 * This is a runtime test, since kernels with a USB-OTG stack sometimes 569 * run on boards which only have a Mini-B (or Mini-A) connector. 570 */ 571 static inline int gadget_is_otg(struct usb_gadget *g) 572 { 573 #ifdef CONFIG_USB_OTG 574 return g->is_otg; 575 #else 576 return 0; 577 #endif 578 } 579 580 /** 581 * usb_gadget_frame_number - returns the current frame number 582 * @gadget: controller that reports the frame number 583 * 584 * Returns the usb frame number, normally eleven bits from a SOF packet, 585 * or negative errno if this device doesn't support this capability. 586 */ 587 static inline int usb_gadget_frame_number(struct usb_gadget *gadget) 588 { 589 return gadget->ops->get_frame(gadget); 590 } 591 592 /** 593 * usb_gadget_wakeup - tries to wake up the host connected to this gadget 594 * @gadget: controller used to wake up the host 595 * 596 * Returns zero on success, else negative error code if the hardware 597 * doesn't support such attempts, or its support has not been enabled 598 * by the usb host. Drivers must return device descriptors that report 599 * their ability to support this, or hosts won't enable it. 600 * 601 * This may also try to use SRP to wake the host and start enumeration, 602 * even if OTG isn't otherwise in use. OTG devices may also start 603 * remote wakeup even when hosts don't explicitly enable it. 604 */ 605 static inline int usb_gadget_wakeup(struct usb_gadget *gadget) 606 { 607 if (!gadget->ops->wakeup) 608 return -EOPNOTSUPP; 609 return gadget->ops->wakeup(gadget); 610 } 611 612 /** 613 * usb_gadget_set_selfpowered - sets the device selfpowered feature. 614 * @gadget:the device being declared as self-powered 615 * 616 * this affects the device status reported by the hardware driver 617 * to reflect that it now has a local power supply. 618 * 619 * returns zero on success, else negative errno. 620 */ 621 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget) 622 { 623 if (!gadget->ops->set_selfpowered) 624 return -EOPNOTSUPP; 625 return gadget->ops->set_selfpowered(gadget, 1); 626 } 627 628 /** 629 * usb_gadget_clear_selfpowered - clear the device selfpowered feature. 630 * @gadget:the device being declared as bus-powered 631 * 632 * this affects the device status reported by the hardware driver. 633 * some hardware may not support bus-powered operation, in which 634 * case this feature's value can never change. 635 * 636 * returns zero on success, else negative errno. 637 */ 638 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget) 639 { 640 if (!gadget->ops->set_selfpowered) 641 return -EOPNOTSUPP; 642 return gadget->ops->set_selfpowered(gadget, 0); 643 } 644 645 /** 646 * usb_gadget_vbus_connect - Notify controller that VBUS is powered 647 * @gadget:The device which now has VBUS power. 648 * 649 * This call is used by a driver for an external transceiver (or GPIO) 650 * that detects a VBUS power session starting. Common responses include 651 * resuming the controller, activating the D+ (or D-) pullup to let the 652 * host detect that a USB device is attached, and starting to draw power 653 * (8mA or possibly more, especially after SET_CONFIGURATION). 654 * 655 * Returns zero on success, else negative errno. 656 */ 657 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget) 658 { 659 if (!gadget->ops->vbus_session) 660 return -EOPNOTSUPP; 661 return gadget->ops->vbus_session(gadget, 1); 662 } 663 664 /** 665 * usb_gadget_vbus_draw - constrain controller's VBUS power usage 666 * @gadget:The device whose VBUS usage is being described 667 * @mA:How much current to draw, in milliAmperes. This should be twice 668 * the value listed in the configuration descriptor bMaxPower field. 669 * 670 * This call is used by gadget drivers during SET_CONFIGURATION calls, 671 * reporting how much power the device may consume. For example, this 672 * could affect how quickly batteries are recharged. 673 * 674 * Returns zero on success, else negative errno. 675 */ 676 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA) 677 { 678 if (!gadget->ops->vbus_draw) 679 return -EOPNOTSUPP; 680 return gadget->ops->vbus_draw(gadget, mA); 681 } 682 683 /** 684 * usb_gadget_vbus_disconnect - notify controller about VBUS session end 685 * @gadget:the device whose VBUS supply is being described 686 * 687 * This call is used by a driver for an external transceiver (or GPIO) 688 * that detects a VBUS power session ending. Common responses include 689 * reversing everything done in usb_gadget_vbus_connect(). 690 * 691 * Returns zero on success, else negative errno. 692 */ 693 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget) 694 { 695 if (!gadget->ops->vbus_session) 696 return -EOPNOTSUPP; 697 return gadget->ops->vbus_session(gadget, 0); 698 } 699 700 /** 701 * usb_gadget_connect - software-controlled connect to USB host 702 * @gadget:the peripheral being connected 703 * 704 * Enables the D+ (or potentially D-) pullup. The host will start 705 * enumerating this gadget when the pullup is active and a VBUS session 706 * is active (the link is powered). This pullup is always enabled unless 707 * usb_gadget_disconnect() has been used to disable it. 708 * 709 * Returns zero on success, else negative errno. 710 */ 711 static inline int usb_gadget_connect(struct usb_gadget *gadget) 712 { 713 if (!gadget->ops->pullup) 714 return -EOPNOTSUPP; 715 return gadget->ops->pullup(gadget, 1); 716 } 717 718 /** 719 * usb_gadget_disconnect - software-controlled disconnect from USB host 720 * @gadget:the peripheral being disconnected 721 * 722 * Disables the D+ (or potentially D-) pullup, which the host may see 723 * as a disconnect (when a VBUS session is active). Not all systems 724 * support software pullup controls. 725 * 726 * This routine may be used during the gadget driver bind() call to prevent 727 * the peripheral from ever being visible to the USB host, unless later 728 * usb_gadget_connect() is called. For example, user mode components may 729 * need to be activated before the system can talk to hosts. 730 * 731 * Returns zero on success, else negative errno. 732 */ 733 static inline int usb_gadget_disconnect(struct usb_gadget *gadget) 734 { 735 if (!gadget->ops->pullup) 736 return -EOPNOTSUPP; 737 return gadget->ops->pullup(gadget, 0); 738 } 739 740 741 /*-------------------------------------------------------------------------*/ 742 743 /** 744 * struct usb_gadget_driver - driver for usb 'slave' devices 745 * @function: String describing the gadget's function 746 * @speed: Highest speed the driver handles. 747 * @bind: Invoked when the driver is bound to a gadget, usually 748 * after registering the driver. 749 * At that point, ep0 is fully initialized, and ep_list holds 750 * the currently-available endpoints. 751 * Called in a context that permits sleeping. 752 * @setup: Invoked for ep0 control requests that aren't handled by 753 * the hardware level driver. Most calls must be handled by 754 * the gadget driver, including descriptor and configuration 755 * management. The 16 bit members of the setup data are in 756 * USB byte order. Called in_interrupt; this may not sleep. Driver 757 * queues a response to ep0, or returns negative to stall. 758 * @disconnect: Invoked after all transfers have been stopped, 759 * when the host is disconnected. May be called in_interrupt; this 760 * may not sleep. Some devices can't detect disconnect, so this might 761 * not be called except as part of controller shutdown. 762 * @unbind: Invoked when the driver is unbound from a gadget, 763 * usually from rmmod (after a disconnect is reported). 764 * Called in a context that permits sleeping. 765 * @suspend: Invoked on USB suspend. May be called in_interrupt. 766 * @resume: Invoked on USB resume. May be called in_interrupt. 767 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers 768 * and should be called in_interrupt. 769 * 770 * Devices are disabled till a gadget driver successfully bind()s, which 771 * means the driver will handle setup() requests needed to enumerate (and 772 * meet "chapter 9" requirements) then do some useful work. 773 * 774 * If gadget->is_otg is true, the gadget driver must provide an OTG 775 * descriptor during enumeration, or else fail the bind() call. In such 776 * cases, no USB traffic may flow until both bind() returns without 777 * having called usb_gadget_disconnect(), and the USB host stack has 778 * initialized. 779 * 780 * Drivers use hardware-specific knowledge to configure the usb hardware. 781 * endpoint addressing is only one of several hardware characteristics that 782 * are in descriptors the ep0 implementation returns from setup() calls. 783 * 784 * Except for ep0 implementation, most driver code shouldn't need change to 785 * run on top of different usb controllers. It'll use endpoints set up by 786 * that ep0 implementation. 787 * 788 * The usb controller driver handles a few standard usb requests. Those 789 * include set_address, and feature flags for devices, interfaces, and 790 * endpoints (the get_status, set_feature, and clear_feature requests). 791 * 792 * Accordingly, the driver's setup() callback must always implement all 793 * get_descriptor requests, returning at least a device descriptor and 794 * a configuration descriptor. Drivers must make sure the endpoint 795 * descriptors match any hardware constraints. Some hardware also constrains 796 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3). 797 * 798 * The driver's setup() callback must also implement set_configuration, 799 * and should also implement set_interface, get_configuration, and 800 * get_interface. Setting a configuration (or interface) is where 801 * endpoints should be activated or (config 0) shut down. 802 * 803 * (Note that only the default control endpoint is supported. Neither 804 * hosts nor devices generally support control traffic except to ep0.) 805 * 806 * Most devices will ignore USB suspend/resume operations, and so will 807 * not provide those callbacks. However, some may need to change modes 808 * when the host is not longer directing those activities. For example, 809 * local controls (buttons, dials, etc) may need to be re-enabled since 810 * the (remote) host can't do that any longer; or an error state might 811 * be cleared, to make the device behave identically whether or not 812 * power is maintained. 813 */ 814 struct usb_gadget_driver { 815 char *function; 816 enum usb_device_speed speed; 817 int (*bind)(struct usb_gadget *); 818 void (*unbind)(struct usb_gadget *); 819 int (*setup)(struct usb_gadget *, 820 const struct usb_ctrlrequest *); 821 void (*disconnect)(struct usb_gadget *); 822 void (*suspend)(struct usb_gadget *); 823 void (*resume)(struct usb_gadget *); 824 void (*reset)(struct usb_gadget *); 825 }; 826 827 828 /*-------------------------------------------------------------------------*/ 829 830 /* driver modules register and unregister, as usual. 831 * these calls must be made in a context that can sleep. 832 * 833 * these will usually be implemented directly by the hardware-dependent 834 * usb bus interface driver, which will only support a single driver. 835 */ 836 837 /** 838 * usb_gadget_register_driver - register a gadget driver 839 * @driver:the driver being registered 840 * 841 * Call this in your gadget driver's module initialization function, 842 * to tell the underlying usb controller driver about your driver. 843 * The driver's bind() function will be called to bind it to a 844 * gadget before this registration call returns. It's expected that 845 * the bind() functions will be in init sections. 846 * This function must be called in a context that can sleep. 847 */ 848 int usb_gadget_register_driver(struct usb_gadget_driver *driver); 849 850 /** 851 * usb_gadget_unregister_driver - unregister a gadget driver 852 * @driver:the driver being unregistered 853 * 854 * Call this in your gadget driver's module cleanup function, 855 * to tell the underlying usb controller that your driver is 856 * going away. If the controller is connected to a USB host, 857 * it will first disconnect(). The driver is also requested 858 * to unbind() and clean up any device state, before this procedure 859 * finally returns. It's expected that the unbind() functions 860 * will in in exit sections, so may not be linked in some kernels. 861 * This function must be called in a context that can sleep. 862 */ 863 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver); 864 865 int usb_add_gadget_udc_release(struct device *parent, 866 struct usb_gadget *gadget, void (*release)(struct device *dev)); 867 int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget); 868 void usb_del_gadget_udc(struct usb_gadget *gadget); 869 /*-------------------------------------------------------------------------*/ 870 871 /* utility to simplify dealing with string descriptors */ 872 873 /** 874 * struct usb_gadget_strings - a set of USB strings in a given language 875 * @language:identifies the strings' language (0x0409 for en-us) 876 * @strings:array of strings with their ids 877 * 878 * If you're using usb_gadget_get_string(), use this to wrap all the 879 * strings for a given language. 880 */ 881 struct usb_gadget_strings { 882 u16 language; /* 0x0409 for en-us */ 883 struct usb_string *strings; 884 }; 885 886 /* put descriptor for string with that id into buf (buflen >= 256) */ 887 int usb_gadget_get_string(struct usb_gadget_strings *table, int id, u8 *buf); 888 889 /*-------------------------------------------------------------------------*/ 890 891 /* utility to simplify managing config descriptors */ 892 893 /* write vector of descriptors into buffer */ 894 int usb_descriptor_fillbuf(void *, unsigned, 895 const struct usb_descriptor_header **); 896 897 /* build config descriptor from single descriptor vector */ 898 int usb_gadget_config_buf(const struct usb_config_descriptor *config, 899 void *buf, unsigned buflen, const struct usb_descriptor_header **desc); 900 901 /*-------------------------------------------------------------------------*/ 902 /* utility to simplify map/unmap of usb_requests to/from DMA */ 903 904 extern int usb_gadget_map_request(struct usb_gadget *gadget, 905 struct usb_request *req, int is_in); 906 907 extern void usb_gadget_unmap_request(struct usb_gadget *gadget, 908 struct usb_request *req, int is_in); 909 910 /*-------------------------------------------------------------------------*/ 911 912 /* utility to set gadget state properly */ 913 914 extern void usb_gadget_set_state(struct usb_gadget *gadget, 915 enum usb_device_state state); 916 917 /*-------------------------------------------------------------------------*/ 918 919 /* utility to tell udc core that the bus reset occurs */ 920 extern void usb_gadget_udc_reset(struct usb_gadget *gadget, 921 struct usb_gadget_driver *driver); 922 923 /*-------------------------------------------------------------------------*/ 924 925 /* utility to give requests back to the gadget layer */ 926 927 extern void usb_gadget_giveback_request(struct usb_ep *ep, 928 struct usb_request *req); 929 930 /*-------------------------------------------------------------------------*/ 931 932 /* utility wrapping a simple endpoint selection policy */ 933 934 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *, 935 struct usb_endpoint_descriptor *); 936 937 extern void usb_ep_autoconfig_reset(struct usb_gadget *); 938 939 extern int usb_gadget_handle_interrupts(int index); 940 941 static inline int usb_gadget_initialize(int index) 942 { 943 return board_usb_init(index, USB_INIT_DEVICE); 944 } 945 946 static inline int usb_gadget_release(int index) 947 { 948 return board_usb_cleanup(index, USB_INIT_DEVICE); 949 } 950 #endif /* __LINUX_USB_GADGET_H */ 951