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 (at) gmail.com> and 15 * Remy Bohmer <linux (at) bohmer.net> 16 */ 17 18 #ifndef __LINUX_USB_GADGET_H 19 #define __LINUX_USB_GADGET_H 20 21 #include <errno.h> 22 #include <linux/compat.h> 23 #include <linux/list.h> 24 25 struct usb_ep; 26 27 /** 28 * struct usb_request - describes one i/o request 29 * @buf: Buffer used for data. Always provide this; some controllers 30 * only use PIO, or don't use DMA for some endpoints. 31 * @dma: DMA address corresponding to 'buf'. If you don't set this 32 * field, and the usb controller needs one, it is responsible 33 * for mapping and unmapping the buffer. 34 * @stream_id: The stream id, when USB3.0 bulk streams are being used 35 * @length: Length of that data 36 * @no_interrupt: If true, hints that no completion irq is needed. 37 * Helpful sometimes with deep request queues that are handled 38 * directly by DMA controllers. 39 * @zero: If true, when writing data, makes the last packet be "short" 40 * by adding a zero length packet as needed; 41 * @short_not_ok: When reading data, makes short packets be 42 * treated as errors (queue stops advancing till cleanup). 43 * @complete: Function called when request completes, so this request and 44 * its buffer may be re-used. 45 * Reads terminate with a short packet, or when the buffer fills, 46 * whichever comes first. When writes terminate, some data bytes 47 * will usually still be in flight (often in a hardware fifo). 48 * Errors (for reads or writes) stop the queue from advancing 49 * until the completion function returns, so that any transfers 50 * invalidated by the error may first be dequeued. 51 * @context: For use by the completion callback 52 * @list: For use by the gadget driver. 53 * @status: Reports completion code, zero or a negative errno. 54 * Normally, faults block the transfer queue from advancing until 55 * the completion callback returns. 56 * Code "-ESHUTDOWN" indicates completion caused by device disconnect, 57 * or when the driver disabled the endpoint. 58 * @actual: Reports bytes transferred to/from the buffer. For reads (OUT 59 * transfers) this may be less than the requested length. If the 60 * short_not_ok flag is set, short reads are treated as errors 61 * even when status otherwise indicates successful completion. 62 * Note that for writes (IN transfers) some data bytes may still 63 * reside in a device-side FIFO when the request is reported as 64 * complete. 65 * 66 * These are allocated/freed through the endpoint they're used with. The 67 * hardware's driver can add extra per-request data to the memory it returns, 68 * which often avoids separate memory allocations (potential failures), 69 * later when the request is queued. 70 * 71 * Request flags affect request handling, such as whether a zero length 72 * packet is written (the "zero" flag), whether a short read should be 73 * treated as an error (blocking request queue advance, the "short_not_ok" 74 * flag), or hinting that an interrupt is not required (the "no_interrupt" 75 * flag, for use with deep request queues). 76 * 77 * Bulk endpoints can use any size buffers, and can also be used for interrupt 78 * transfers. interrupt-only endpoints can be much less functional. 79 * 80 * NOTE: this is analagous to 'struct urb' on the host side, except that 81 * it's thinner and promotes more pre-allocation. 82 */ 83 84 struct usb_request { 85 void *buf; 86 unsigned length; 87 dma_addr_t dma; 88 89 unsigned stream_id:16; 90 unsigned no_interrupt:1; 91 unsigned zero:1; 92 unsigned short_not_ok:1; 93 94 void (*complete)(struct usb_ep *ep, 95 struct usb_request *req); 96 void *context; 97 struct list_head list; 98 99 int status; 100 unsigned actual; 101 }; 102 103 /*-------------------------------------------------------------------------*/ 104 105 /* endpoint-specific parts of the api to the usb controller hardware. 106 * unlike the urb model, (de)multiplexing layers are not required. 107 * (so this api could slash overhead if used on the host side...) 108 * 109 * note that device side usb controllers commonly differ in how many 110 * endpoints they support, as well as their capabilities. 111 */ 112 struct usb_ep_ops { 113 int (*enable) (struct usb_ep *ep, 114 const struct usb_endpoint_descriptor *desc); 115 int (*disable) (struct usb_ep *ep); 116 117 struct usb_request *(*alloc_request) (struct usb_ep *ep, 118 gfp_t gfp_flags); 119 void (*free_request) (struct usb_ep *ep, struct usb_request *req); 120 121 int (*queue) (struct usb_ep *ep, struct usb_request *req, 122 gfp_t gfp_flags); 123 int (*dequeue) (struct usb_ep *ep, struct usb_request *req); 124 125 int (*set_halt) (struct usb_ep *ep, int value); 126 int (*set_wedge)(struct usb_ep *ep); 127 int (*fifo_status) (struct usb_ep *ep); 128 void (*fifo_flush) (struct usb_ep *ep); 129 }; 130 131 /** 132 * struct usb_ep - device side representation of USB endpoint 133 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk" 134 * @ops: Function pointers used to access hardware-specific operations. 135 * @ep_list:the gadget's ep_list holds all of its endpoints 136 * @maxpacket:The maximum packet size used on this endpoint. The initial 137 * value can sometimes be reduced (hardware allowing), according to 138 * the endpoint descriptor used to configure the endpoint. 139 * @maxpacket_limit:The maximum packet size value which can be handled by this 140 * endpoint. It's set once by UDC driver when endpoint is initialized, and 141 * should not be changed. Should not be confused with maxpacket. 142 * @max_streams: The maximum number of streams supported 143 * by this EP (0 - 16, actual number is 2^n) 144 * @maxburst: the maximum number of bursts supported by this EP (for usb3) 145 * @driver_data:for use by the gadget driver. all other fields are 146 * read-only to gadget drivers. 147 * @desc: endpoint descriptor. This pointer is set before the endpoint is 148 * enabled and remains valid until the endpoint is disabled. 149 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion 150 * descriptor that is used to configure the endpoint 151 * 152 * the bus controller driver lists all the general purpose endpoints in 153 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list, 154 * and is accessed only in response to a driver setup() callback. 155 */ 156 struct usb_ep { 157 void *driver_data; 158 const char *name; 159 const struct usb_ep_ops *ops; 160 struct list_head ep_list; 161 unsigned maxpacket:16; 162 unsigned maxpacket_limit:16; 163 unsigned max_streams:16; 164 unsigned maxburst:5; 165 const struct usb_endpoint_descriptor *desc; 166 const struct usb_ss_ep_comp_descriptor *comp_desc; 167 }; 168 169 /*-------------------------------------------------------------------------*/ 170 171 /** 172 * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint 173 * @ep:the endpoint being configured 174 * @maxpacket_limit:value of maximum packet size limit 175 * 176 * This function shoud be used only in UDC drivers to initialize endpoint 177 * (usually in probe function). 178 */ 179 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep, 180 unsigned maxpacket_limit) 181 { 182 ep->maxpacket_limit = maxpacket_limit; 183 ep->maxpacket = maxpacket_limit; 184 } 185 186 /** 187 * usb_ep_enable - configure endpoint, making it usable 188 * @ep:the endpoint being configured. may not be the endpoint named "ep0". 189 * drivers discover endpoints through the ep_list of a usb_gadget. 190 * @desc:descriptor for desired behavior. caller guarantees this pointer 191 * remains valid until the endpoint is disabled; the data byte order 192 * is little-endian (usb-standard). 193 * 194 * when configurations are set, or when interface settings change, the driver 195 * will enable or disable the relevant endpoints. while it is enabled, an 196 * endpoint may be used for i/o until the driver receives a disconnect() from 197 * the host or until the endpoint is disabled. 198 * 199 * the ep0 implementation (which calls this routine) must ensure that the 200 * hardware capabilities of each endpoint match the descriptor provided 201 * for it. for example, an endpoint named "ep2in-bulk" would be usable 202 * for interrupt transfers as well as bulk, but it likely couldn't be used 203 * for iso transfers or for endpoint 14. some endpoints are fully 204 * configurable, with more generic names like "ep-a". (remember that for 205 * USB, "in" means "towards the USB master".) 206 * 207 * returns zero, or a negative error code. 208 */ 209 static inline int usb_ep_enable(struct usb_ep *ep, 210 const struct usb_endpoint_descriptor *desc) 211 { 212 return ep->ops->enable(ep, desc); 213 } 214 215 /** 216 * usb_ep_disable - endpoint is no longer usable 217 * @ep:the endpoint being unconfigured. may not be the endpoint named "ep0". 218 * 219 * no other task may be using this endpoint when this is called. 220 * any pending and uncompleted requests will complete with status 221 * indicating disconnect (-ESHUTDOWN) before this call returns. 222 * gadget drivers must call usb_ep_enable() again before queueing 223 * requests to the endpoint. 224 * 225 * returns zero, or a negative error code. 226 */ 227 static inline int usb_ep_disable(struct usb_ep *ep) 228 { 229 return ep->ops->disable(ep); 230 } 231 232 /** 233 * usb_ep_alloc_request - allocate a request object to use with this endpoint 234 * @ep:the endpoint to be used with with the request 235 * @gfp_flags:GFP_* flags to use 236 * 237 * Request objects must be allocated with this call, since they normally 238 * need controller-specific setup and may even need endpoint-specific 239 * resources such as allocation of DMA descriptors. 240 * Requests may be submitted with usb_ep_queue(), and receive a single 241 * completion callback. Free requests with usb_ep_free_request(), when 242 * they are no longer needed. 243 * 244 * Returns the request, or null if one could not be allocated. 245 */ 246 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, 247 gfp_t gfp_flags) 248 { 249 return ep->ops->alloc_request(ep, gfp_flags); 250 } 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 /** 268 * usb_ep_queue - queues (submits) an I/O request to an endpoint. 269 * @ep:the endpoint associated with the request 270 * @req:the request being submitted 271 * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't 272 * pre-allocate all necessary memory with the request. 273 * 274 * This tells the device controller to perform the specified request through 275 * that endpoint (reading or writing a buffer). When the request completes, 276 * including being canceled by usb_ep_dequeue(), the request's completion 277 * routine is called to return the request to the driver. Any endpoint 278 * (except control endpoints like ep0) may have more than one transfer 279 * request queued; they complete in FIFO order. Once a gadget driver 280 * submits a request, that request may not be examined or modified until it 281 * is given back to that driver through the completion callback. 282 * 283 * Each request is turned into one or more packets. The controller driver 284 * never merges adjacent requests into the same packet. OUT transfers 285 * will sometimes use data that's already buffered in the hardware. 286 * Drivers can rely on the fact that the first byte of the request's buffer 287 * always corresponds to the first byte of some USB packet, for both 288 * IN and OUT transfers. 289 * 290 * Bulk endpoints can queue any amount of data; the transfer is packetized 291 * automatically. The last packet will be short if the request doesn't fill it 292 * out completely. Zero length packets (ZLPs) should be avoided in portable 293 * protocols since not all usb hardware can successfully handle zero length 294 * packets. (ZLPs may be explicitly written, and may be implicitly written if 295 * the request 'zero' flag is set.) Bulk endpoints may also be used 296 * for interrupt transfers; but the reverse is not true, and some endpoints 297 * won't support every interrupt transfer. (Such as 768 byte packets.) 298 * 299 * Interrupt-only endpoints are less functional than bulk endpoints, for 300 * example by not supporting queueing or not handling buffers that are 301 * larger than the endpoint's maxpacket size. They may also treat data 302 * toggle differently. 303 * 304 * Control endpoints ... after getting a setup() callback, the driver queues 305 * one response (even if it would be zero length). That enables the 306 * status ack, after transfering data as specified in the response. Setup 307 * functions may return negative error codes to generate protocol stalls. 308 * (Note that some USB device controllers disallow protocol stall responses 309 * in some cases.) When control responses are deferred (the response is 310 * written after the setup callback returns), then usb_ep_set_halt() may be 311 * used on ep0 to trigger protocol stalls. 312 * 313 * For periodic endpoints, like interrupt or isochronous ones, the usb host 314 * arranges to poll once per interval, and the gadget driver usually will 315 * have queued some data to transfer at that time. 316 * 317 * Returns zero, or a negative error code. Endpoints that are not enabled 318 * report errors; errors will also be 319 * reported when the usb peripheral is disconnected. 320 */ 321 static inline int usb_ep_queue(struct usb_ep *ep, 322 struct usb_request *req, gfp_t gfp_flags) 323 { 324 return ep->ops->queue(ep, req, gfp_flags); 325 } 326 327 /** 328 * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint 329 * @ep:the endpoint associated with the request 330 * @req:the request being canceled 331 * 332 * if the request is still active on the endpoint, it is dequeued and its 333 * completion routine is called (with status -ECONNRESET); else a negative 334 * error code is returned. 335 * 336 * note that some hardware can't clear out write fifos (to unlink the request 337 * at the head of the queue) except as part of disconnecting from usb. such 338 * restrictions prevent drivers from supporting configuration changes, 339 * even to configuration zero (a "chapter 9" requirement). 340 */ 341 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req) 342 { 343 return ep->ops->dequeue(ep, req); 344 } 345 346 /** 347 * usb_ep_set_halt - sets the endpoint halt feature. 348 * @ep: the non-isochronous endpoint being stalled 349 * 350 * Use this to stall an endpoint, perhaps as an error report. 351 * Except for control endpoints, 352 * the endpoint stays halted (will not stream any data) until the host 353 * clears this feature; drivers may need to empty the endpoint's request 354 * queue first, to make sure no inappropriate transfers happen. 355 * 356 * Note that while an endpoint CLEAR_FEATURE will be invisible to the 357 * gadget driver, a SET_INTERFACE will not be. To reset endpoints for the 358 * current altsetting, see usb_ep_clear_halt(). When switching altsettings, 359 * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints. 360 * 361 * Returns zero, or a negative error code. On success, this call sets 362 * underlying hardware state that blocks data transfers. 363 * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any 364 * transfer requests are still queued, or if the controller hardware 365 * (usually a FIFO) still holds bytes that the host hasn't collected. 366 */ 367 static inline int usb_ep_set_halt(struct usb_ep *ep) 368 { 369 return ep->ops->set_halt(ep, 1); 370 } 371 372 /** 373 * usb_ep_clear_halt - clears endpoint halt, and resets toggle 374 * @ep:the bulk or interrupt endpoint being reset 375 * 376 * Use this when responding to the standard usb "set interface" request, 377 * for endpoints that aren't reconfigured, after clearing any other state 378 * in the endpoint's i/o queue. 379 * 380 * Returns zero, or a negative error code. On success, this call clears 381 * the underlying hardware state reflecting endpoint halt and data toggle. 382 * Note that some hardware can't support this request (like pxa2xx_udc), 383 * and accordingly can't correctly implement interface altsettings. 384 */ 385 static inline int usb_ep_clear_halt(struct usb_ep *ep) 386 { 387 return ep->ops->set_halt(ep, 0); 388 } 389 390 /** 391 * usb_ep_fifo_status - returns number of bytes in fifo, or error 392 * @ep: the endpoint whose fifo status is being checked. 393 * 394 * FIFO endpoints may have "unclaimed data" in them in certain cases, 395 * such as after aborted transfers. Hosts may not have collected all 396 * the IN data written by the gadget driver (and reported by a request 397 * completion). The gadget driver may not have collected all the data 398 * written OUT to it by the host. Drivers that need precise handling for 399 * fault reporting or recovery may need to use this call. 400 * 401 * This returns the number of such bytes in the fifo, or a negative 402 * errno if the endpoint doesn't use a FIFO or doesn't support such 403 * precise handling. 404 */ 405 static inline int usb_ep_fifo_status(struct usb_ep *ep) 406 { 407 if (ep->ops->fifo_status) 408 return ep->ops->fifo_status(ep); 409 else 410 return -EOPNOTSUPP; 411 } 412 413 /** 414 * usb_ep_fifo_flush - flushes contents of a fifo 415 * @ep: the endpoint whose fifo is being flushed. 416 * 417 * This call may be used to flush the "unclaimed data" that may exist in 418 * an endpoint fifo after abnormal transaction terminations. The call 419 * must never be used except when endpoint is not being used for any 420 * protocol translation. 421 */ 422 static inline void usb_ep_fifo_flush(struct usb_ep *ep) 423 { 424 if (ep->ops->fifo_flush) 425 ep->ops->fifo_flush(ep); 426 } 427 428 429 /*-------------------------------------------------------------------------*/ 430 431 struct usb_gadget; 432 struct usb_gadget_driver; 433 434 /* the rest of the api to the controller hardware: device operations, 435 * which don't involve endpoints (or i/o). 436 */ 437 struct usb_gadget_ops { 438 int (*get_frame)(struct usb_gadget *); 439 int (*wakeup)(struct usb_gadget *); 440 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered); 441 int (*vbus_session) (struct usb_gadget *, int is_active); 442 int (*vbus_draw) (struct usb_gadget *, unsigned mA); 443 int (*pullup) (struct usb_gadget *, int is_on); 444 int (*ioctl)(struct usb_gadget *, 445 unsigned code, unsigned long param); 446 int (*udc_start)(struct usb_gadget *, 447 struct usb_gadget_driver *); 448 int (*udc_stop)(struct usb_gadget *); 449 }; 450 451 /** 452 * struct usb_gadget - represents a usb slave device 453 * @ops: Function pointers used to access hardware-specific operations. 454 * @ep0: Endpoint zero, used when reading or writing responses to 455 * driver setup() requests 456 * @ep_list: List of other endpoints supported by the device. 457 * @speed: Speed of current connection to USB host. 458 * @max_speed: Maximal speed the UDC can handle. UDC must support this 459 * and all slower speeds. 460 * @is_dualspeed: true if the controller supports both high and full speed 461 * operation. If it does, the gadget driver must also support both. 462 * @is_otg: true if the USB device port uses a Mini-AB jack, so that the 463 * gadget driver must provide a USB OTG descriptor. 464 * @is_a_peripheral: false unless is_otg, the "A" end of a USB cable 465 * is in the Mini-AB jack, and HNP has been used to switch roles 466 * so that the "A" device currently acts as A-Peripheral, not A-Host. 467 * @a_hnp_support: OTG device feature flag, indicating that the A-Host 468 * supports HNP at this port. 469 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host 470 * only supports HNP on a different root port. 471 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host 472 * enabled HNP support. 473 * @name: Identifies the controller hardware type. Used in diagnostics 474 * and sometimes configuration. 475 * @dev: Driver model state for this abstract device. 476 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to 477 * MaxPacketSize. 478 * 479 * Gadgets have a mostly-portable "gadget driver" implementing device 480 * functions, handling all usb configurations and interfaces. Gadget 481 * drivers talk to hardware-specific code indirectly, through ops vectors. 482 * That insulates the gadget driver from hardware details, and packages 483 * the hardware endpoints through generic i/o queues. The "usb_gadget" 484 * and "usb_ep" interfaces provide that insulation from the hardware. 485 * 486 * Except for the driver data, all fields in this structure are 487 * read-only to the gadget driver. That driver data is part of the 488 * "driver model" infrastructure in 2.6 (and later) kernels, and for 489 * earlier systems is grouped in a similar structure that's not known 490 * to the rest of the kernel. 491 * 492 * Values of the three OTG device feature flags are updated before the 493 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before 494 * driver suspend() calls. They are valid only when is_otg, and when the 495 * device is acting as a B-Peripheral (so is_a_peripheral is false). 496 */ 497 struct usb_gadget { 498 /* readonly to gadget driver */ 499 const struct usb_gadget_ops *ops; 500 struct usb_ep *ep0; 501 struct list_head ep_list; /* of usb_ep */ 502 enum usb_device_speed speed; 503 enum usb_device_speed max_speed; 504 enum usb_device_state state; 505 unsigned is_dualspeed:1; 506 unsigned is_otg:1; 507 unsigned is_a_peripheral:1; 508 unsigned b_hnp_enable:1; 509 unsigned a_hnp_support:1; 510 unsigned a_alt_hnp_support:1; 511 const char *name; 512 struct device dev; 513 unsigned quirk_ep_out_aligned_size:1; 514 }; 515 516 static inline void set_gadget_data(struct usb_gadget *gadget, void *data) 517 { 518 gadget->dev.driver_data = data; 519 } 520 521 static inline void *get_gadget_data(struct usb_gadget *gadget) 522 { 523 return gadget->dev.driver_data; 524 } 525 526 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev) 527 { 528 return container_of(dev, struct usb_gadget, dev); 529 } 530 531 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */ 532 #define gadget_for_each_ep(tmp, gadget) \ 533 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list) 534 535 536 /** 537 * gadget_is_dualspeed - return true iff the hardware handles high speed 538 * @g: controller that might support both high and full speeds 539 */ 540 static inline int gadget_is_dualspeed(struct usb_gadget *g) 541 { 542 #ifdef CONFIG_USB_GADGET_DUALSPEED 543 /* runtime test would check "g->is_dualspeed" ... that might be 544 * useful to work around hardware bugs, but is mostly pointless 545 */ 546 return 1; 547 #else 548 return 0; 549 #endif 550 } 551 552 /** 553 * gadget_is_otg - return true iff the hardware is OTG-ready 554 * @g: controller that might have a Mini-AB connector 555 * 556 * This is a runtime test, since kernels with a USB-OTG stack sometimes 557 * run on boards which only have a Mini-B (or Mini-A) connector. 558 */ 559 static inline int gadget_is_otg(struct usb_gadget *g) 560 { 561 #ifdef CONFIG_USB_OTG 562 return g->is_otg; 563 #else 564 return 0; 565 #endif 566 } 567 568 /** 569 * usb_gadget_frame_number - returns the current frame number 570 * @gadget: controller that reports the frame number 571 * 572 * Returns the usb frame number, normally eleven bits from a SOF packet, 573 * or negative errno if this device doesn't support this capability. 574 */ 575 static inline int usb_gadget_frame_number(struct usb_gadget *gadget) 576 { 577 return gadget->ops->get_frame(gadget); 578 } 579 580 /** 581 * usb_gadget_wakeup - tries to wake up the host connected to this gadget 582 * @gadget: controller used to wake up the host 583 * 584 * Returns zero on success, else negative error code if the hardware 585 * doesn't support such attempts, or its support has not been enabled 586 * by the usb host. Drivers must return device descriptors that report 587 * their ability to support this, or hosts won't enable it. 588 * 589 * This may also try to use SRP to wake the host and start enumeration, 590 * even if OTG isn't otherwise in use. OTG devices may also start 591 * remote wakeup even when hosts don't explicitly enable it. 592 */ 593 static inline int usb_gadget_wakeup(struct usb_gadget *gadget) 594 { 595 if (!gadget->ops->wakeup) 596 return -EOPNOTSUPP; 597 return gadget->ops->wakeup(gadget); 598 } 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 /** 617 * usb_gadget_clear_selfpowered - clear the device selfpowered feature. 618 * @gadget:the device being declared as bus-powered 619 * 620 * this affects the device status reported by the hardware driver. 621 * some hardware may not support bus-powered operation, in which 622 * case this feature's value can never change. 623 * 624 * returns zero on success, else negative errno. 625 */ 626 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget) 627 { 628 if (!gadget->ops->set_selfpowered) 629 return -EOPNOTSUPP; 630 return gadget->ops->set_selfpowered(gadget, 0); 631 } 632 633 /** 634 * usb_gadget_vbus_connect - Notify controller that VBUS is powered 635 * @gadget:The device which now has VBUS power. 636 * 637 * This call is used by a driver for an external transceiver (or GPIO) 638 * that detects a VBUS power session starting. Common responses include 639 * resuming the controller, activating the D+ (or D-) pullup to let the 640 * host detect that a USB device is attached, and starting to draw power 641 * (8mA or possibly more, especially after SET_CONFIGURATION). 642 * 643 * Returns zero on success, else negative errno. 644 */ 645 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget) 646 { 647 if (!gadget->ops->vbus_session) 648 return -EOPNOTSUPP; 649 return gadget->ops->vbus_session(gadget, 1); 650 } 651 652 /** 653 * usb_gadget_vbus_draw - constrain controller's VBUS power usage 654 * @gadget:The device whose VBUS usage is being described 655 * @mA:How much current to draw, in milliAmperes. This should be twice 656 * the value listed in the configuration descriptor bMaxPower field. 657 * 658 * This call is used by gadget drivers during SET_CONFIGURATION calls, 659 * reporting how much power the device may consume. For example, this 660 * could affect how quickly batteries are recharged. 661 * 662 * Returns zero on success, else negative errno. 663 */ 664 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA) 665 { 666 if (!gadget->ops->vbus_draw) 667 return -EOPNOTSUPP; 668 return gadget->ops->vbus_draw(gadget, mA); 669 } 670 671 /** 672 * usb_gadget_vbus_disconnect - notify controller about VBUS session end 673 * @gadget:the device whose VBUS supply is being described 674 * 675 * This call is used by a driver for an external transceiver (or GPIO) 676 * that detects a VBUS power session ending. Common responses include 677 * reversing everything done in usb_gadget_vbus_connect(). 678 * 679 * Returns zero on success, else negative errno. 680 */ 681 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget) 682 { 683 if (!gadget->ops->vbus_session) 684 return -EOPNOTSUPP; 685 return gadget->ops->vbus_session(gadget, 0); 686 } 687 688 /** 689 * usb_gadget_connect - software-controlled connect to USB host 690 * @gadget:the peripheral being connected 691 * 692 * Enables the D+ (or potentially D-) pullup. The host will start 693 * enumerating this gadget when the pullup is active and a VBUS session 694 * is active (the link is powered). This pullup is always enabled unless 695 * usb_gadget_disconnect() has been used to disable it. 696 * 697 * Returns zero on success, else negative errno. 698 */ 699 static inline int usb_gadget_connect(struct usb_gadget *gadget) 700 { 701 if (!gadget->ops->pullup) 702 return -EOPNOTSUPP; 703 return gadget->ops->pullup(gadget, 1); 704 } 705 706 /** 707 * usb_gadget_disconnect - software-controlled disconnect from USB host 708 * @gadget:the peripheral being disconnected 709 * 710 * Disables the D+ (or potentially D-) pullup, which the host may see 711 * as a disconnect (when a VBUS session is active). Not all systems 712 * support software pullup controls. 713 * 714 * This routine may be used during the gadget driver bind() call to prevent 715 * the peripheral from ever being visible to the USB host, unless later 716 * usb_gadget_connect() is called. For example, user mode components may 717 * need to be activated before the system can talk to hosts. 718 * 719 * Returns zero on success, else negative errno. 720 */ 721 static inline int usb_gadget_disconnect(struct usb_gadget *gadget) 722 { 723 if (!gadget->ops->pullup) 724 return -EOPNOTSUPP; 725 return gadget->ops->pullup(gadget, 0); 726 } 727 728 729 /*-------------------------------------------------------------------------*/ 730 731 /** 732 * struct usb_gadget_driver - driver for usb 'slave' devices 733 * @function: String describing the gadget's function 734 * @speed: Highest speed the driver handles. 735 * @bind: Invoked when the driver is bound to a gadget, usually 736 * after registering the driver. 737 * At that point, ep0 is fully initialized, and ep_list holds 738 * the currently-available endpoints. 739 * Called in a context that permits sleeping. 740 * @setup: Invoked for ep0 control requests that aren't handled by 741 * the hardware level driver. Most calls must be handled by 742 * the gadget driver, including descriptor and configuration 743 * management. The 16 bit members of the setup data are in 744 * USB byte order. Called in_interrupt; this may not sleep. Driver 745 * queues a response to ep0, or returns negative to stall. 746 * @disconnect: Invoked after all transfers have been stopped, 747 * when the host is disconnected. May be called in_interrupt; this 748 * may not sleep. Some devices can't detect disconnect, so this might 749 * not be called except as part of controller shutdown. 750 * @unbind: Invoked when the driver is unbound from a gadget, 751 * usually from rmmod (after a disconnect is reported). 752 * Called in a context that permits sleeping. 753 * @suspend: Invoked on USB suspend. May be called in_interrupt. 754 * @resume: Invoked on USB resume. May be called in_interrupt. 755 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers 756 * and should be called in_interrupt. 757 * 758 * Devices are disabled till a gadget driver successfully bind()s, which 759 * means the driver will handle setup() requests needed to enumerate (and 760 * meet "chapter 9" requirements) then do some useful work. 761 * 762 * If gadget->is_otg is true, the gadget driver must provide an OTG 763 * descriptor during enumeration, or else fail the bind() call. In such 764 * cases, no USB traffic may flow until both bind() returns without 765 * having called usb_gadget_disconnect(), and the USB host stack has 766 * initialized. 767 * 768 * Drivers use hardware-specific knowledge to configure the usb hardware. 769 * endpoint addressing is only one of several hardware characteristics that 770 * are in descriptors the ep0 implementation returns from setup() calls. 771 * 772 * Except for ep0 implementation, most driver code shouldn't need change to 773 * run on top of different usb controllers. It'll use endpoints set up by 774 * that ep0 implementation. 775 * 776 * The usb controller driver handles a few standard usb requests. Those 777 * include set_address, and feature flags for devices, interfaces, and 778 * endpoints (the get_status, set_feature, and clear_feature requests). 779 * 780 * Accordingly, the driver's setup() callback must always implement all 781 * get_descriptor requests, returning at least a device descriptor and 782 * a configuration descriptor. Drivers must make sure the endpoint 783 * descriptors match any hardware constraints. Some hardware also constrains 784 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3). 785 * 786 * The driver's setup() callback must also implement set_configuration, 787 * and should also implement set_interface, get_configuration, and 788 * get_interface. Setting a configuration (or interface) is where 789 * endpoints should be activated or (config 0) shut down. 790 * 791 * (Note that only the default control endpoint is supported. Neither 792 * hosts nor devices generally support control traffic except to ep0.) 793 * 794 * Most devices will ignore USB suspend/resume operations, and so will 795 * not provide those callbacks. However, some may need to change modes 796 * when the host is not longer directing those activities. For example, 797 * local controls (buttons, dials, etc) may need to be re-enabled since 798 * the (remote) host can't do that any longer; or an error state might 799 * be cleared, to make the device behave identically whether or not 800 * power is maintained. 801 */ 802 struct usb_gadget_driver { 803 char *function; 804 enum usb_device_speed speed; 805 int (*bind)(struct usb_gadget *); 806 void (*unbind)(struct usb_gadget *); 807 int (*setup)(struct usb_gadget *, 808 const struct usb_ctrlrequest *); 809 void (*disconnect)(struct usb_gadget *); 810 void (*suspend)(struct usb_gadget *); 811 void (*resume)(struct usb_gadget *); 812 void (*reset)(struct usb_gadget *); 813 }; 814 815 816 /*-------------------------------------------------------------------------*/ 817 818 /* driver modules register and unregister, as usual. 819 * these calls must be made in a context that can sleep. 820 * 821 * these will usually be implemented directly by the hardware-dependent 822 * usb bus interface driver, which will only support a single driver. 823 */ 824 825 /** 826 * usb_gadget_register_driver - register a gadget driver 827 * @driver:the driver being registered 828 * 829 * Call this in your gadget driver's module initialization function, 830 * to tell the underlying usb controller driver about your driver. 831 * The driver's bind() function will be called to bind it to a 832 * gadget before this registration call returns. It's expected that 833 * the bind() functions will be in init sections. 834 * This function must be called in a context that can sleep. 835 */ 836 int usb_gadget_register_driver(struct usb_gadget_driver *driver); 837 838 /** 839 * usb_gadget_unregister_driver - unregister a gadget driver 840 * @driver:the driver being unregistered 841 * 842 * Call this in your gadget driver's module cleanup function, 843 * to tell the underlying usb controller that your driver is 844 * going away. If the controller is connected to a USB host, 845 * it will first disconnect(). The driver is also requested 846 * to unbind() and clean up any device state, before this procedure 847 * finally returns. It's expected that the unbind() functions 848 * will in in exit sections, so may not be linked in some kernels. 849 * This function must be called in a context that can sleep. 850 */ 851 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver); 852 853 int usb_add_gadget_udc_release(struct device *parent, 854 struct usb_gadget *gadget, void (*release)(struct device *dev)); 855 int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget); 856 void usb_del_gadget_udc(struct usb_gadget *gadget); 857 /*-------------------------------------------------------------------------*/ 858 859 /* utility to simplify dealing with string descriptors */ 860 861 /** 862 * struct usb_gadget_strings - a set of USB strings in a given language 863 * @language:identifies the strings' language (0x0409 for en-us) 864 * @strings:array of strings with their ids 865 * 866 * If you're using usb_gadget_get_string(), use this to wrap all the 867 * strings for a given language. 868 */ 869 struct usb_gadget_strings { 870 u16 language; /* 0x0409 for en-us */ 871 struct usb_string *strings; 872 }; 873 874 /* put descriptor for string with that id into buf (buflen >= 256) */ 875 int usb_gadget_get_string(struct usb_gadget_strings *table, int id, u8 *buf); 876 877 /*-------------------------------------------------------------------------*/ 878 879 /* utility to simplify managing config descriptors */ 880 881 /* write vector of descriptors into buffer */ 882 int usb_descriptor_fillbuf(void *, unsigned, 883 const struct usb_descriptor_header **); 884 885 /* build config descriptor from single descriptor vector */ 886 int usb_gadget_config_buf(const struct usb_config_descriptor *config, 887 void *buf, unsigned buflen, const struct usb_descriptor_header **desc); 888 889 /*-------------------------------------------------------------------------*/ 890 /* utility to simplify map/unmap of usb_requests to/from DMA */ 891 892 extern int usb_gadget_map_request(struct usb_gadget *gadget, 893 struct usb_request *req, int is_in); 894 895 extern void usb_gadget_unmap_request(struct usb_gadget *gadget, 896 struct usb_request *req, int is_in); 897 898 /*-------------------------------------------------------------------------*/ 899 900 /* utility to set gadget state properly */ 901 902 extern void usb_gadget_set_state(struct usb_gadget *gadget, 903 enum usb_device_state state); 904 905 /*-------------------------------------------------------------------------*/ 906 907 /* utility to tell udc core that the bus reset occurs */ 908 extern void usb_gadget_udc_reset(struct usb_gadget *gadget, 909 struct usb_gadget_driver *driver); 910 911 /*-------------------------------------------------------------------------*/ 912 913 /* utility to give requests back to the gadget layer */ 914 915 extern void usb_gadget_giveback_request(struct usb_ep *ep, 916 struct usb_request *req); 917 918 /*-------------------------------------------------------------------------*/ 919 920 /* utility wrapping a simple endpoint selection policy */ 921 922 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *, 923 struct usb_endpoint_descriptor *); 924 925 extern void usb_ep_autoconfig_reset(struct usb_gadget *); 926 927 extern int usb_gadget_handle_interrupts(int index); 928 929 #endif /* __LINUX_USB_GADGET_H */ 930
