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 <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 #define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */ 431 #define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */ 432 433 struct usb_gadget; 434 struct usb_gadget_driver; 435 436 /* the rest of the api to the controller hardware: device operations, 437 * which don't involve endpoints (or i/o). 438 */ 439 struct usb_gadget_ops { 440 int (*get_frame)(struct usb_gadget *); 441 int (*wakeup)(struct usb_gadget *); 442 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered); 443 int (*vbus_session) (struct usb_gadget *, int is_active); 444 int (*vbus_draw) (struct usb_gadget *, unsigned mA); 445 int (*pullup) (struct usb_gadget *, int is_on); 446 int (*ioctl)(struct usb_gadget *, 447 unsigned code, unsigned long param); 448 int (*udc_start)(struct usb_gadget *, 449 struct usb_gadget_driver *); 450 int (*udc_stop)(struct usb_gadget *); 451 }; 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 }; 517 518 static inline void set_gadget_data(struct usb_gadget *gadget, void *data) 519 { 520 gadget->dev.driver_data = data; 521 } 522 523 static inline void *get_gadget_data(struct usb_gadget *gadget) 524 { 525 return gadget->dev.driver_data; 526 } 527 528 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev) 529 { 530 return container_of(dev, struct usb_gadget, dev); 531 } 532 533 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */ 534 #define gadget_for_each_ep(tmp, gadget) \ 535 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list) 536 537 538 /** 539 * gadget_is_dualspeed - return true iff the hardware handles high speed 540 * @g: controller that might support both high and full speeds 541 */ 542 static inline int gadget_is_dualspeed(struct usb_gadget *g) 543 { 544 #ifdef CONFIG_USB_GADGET_DUALSPEED 545 /* runtime test would check "g->is_dualspeed" ... that might be 546 * useful to work around hardware bugs, but is mostly pointless 547 */ 548 return 1; 549 #else 550 return 0; 551 #endif 552 } 553 554 /** 555 * gadget_is_superspeed() - return true if the hardware handles superspeed 556 * @g: controller that might support superspeed 557 */ 558 static inline int gadget_is_superspeed(struct usb_gadget *g) 559 { 560 return g->max_speed >= USB_SPEED_SUPER; 561 } 562 563 /** 564 * gadget_is_otg - return true iff the hardware is OTG-ready 565 * @g: controller that might have a Mini-AB connector 566 * 567 * This is a runtime test, since kernels with a USB-OTG stack sometimes 568 * run on boards which only have a Mini-B (or Mini-A) connector. 569 */ 570 static inline int gadget_is_otg(struct usb_gadget *g) 571 { 572 #ifdef CONFIG_USB_OTG 573 return g->is_otg; 574 #else 575 return 0; 576 #endif 577 } 578 579 /** 580 * usb_gadget_frame_number - returns the current frame number 581 * @gadget: controller that reports the frame number 582 * 583 * Returns the usb frame number, normally eleven bits from a SOF packet, 584 * or negative errno if this device doesn't support this capability. 585 */ 586 static inline int usb_gadget_frame_number(struct usb_gadget *gadget) 587 { 588 return gadget->ops->get_frame(gadget); 589 } 590 591 /** 592 * usb_gadget_wakeup - tries to wake up the host connected to this gadget 593 * @gadget: controller used to wake up the host 594 * 595 * Returns zero on success, else negative error code if the hardware 596 * doesn't support such attempts, or its support has not been enabled 597 * by the usb host. Drivers must return device descriptors that report 598 * their ability to support this, or hosts won't enable it. 599 * 600 * This may also try to use SRP to wake the host and start enumeration, 601 * even if OTG isn't otherwise in use. OTG devices may also start 602 * remote wakeup even when hosts don't explicitly enable it. 603 */ 604 static inline int usb_gadget_wakeup(struct usb_gadget *gadget) 605 { 606 if (!gadget->ops->wakeup) 607 return -EOPNOTSUPP; 608 return gadget->ops->wakeup(gadget); 609 } 610 611 /** 612 * usb_gadget_set_selfpowered - sets the device selfpowered feature. 613 * @gadget:the device being declared as self-powered 614 * 615 * this affects the device status reported by the hardware driver 616 * to reflect that it now has a local power supply. 617 * 618 * returns zero on success, else negative errno. 619 */ 620 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget) 621 { 622 if (!gadget->ops->set_selfpowered) 623 return -EOPNOTSUPP; 624 return gadget->ops->set_selfpowered(gadget, 1); 625 } 626 627 /** 628 * usb_gadget_clear_selfpowered - clear the device selfpowered feature. 629 * @gadget:the device being declared as bus-powered 630 * 631 * this affects the device status reported by the hardware driver. 632 * some hardware may not support bus-powered operation, in which 633 * case this feature's value can never change. 634 * 635 * returns zero on success, else negative errno. 636 */ 637 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget) 638 { 639 if (!gadget->ops->set_selfpowered) 640 return -EOPNOTSUPP; 641 return gadget->ops->set_selfpowered(gadget, 0); 642 } 643 644 /** 645 * usb_gadget_vbus_connect - Notify controller that VBUS is powered 646 * @gadget:The device which now has VBUS power. 647 * 648 * This call is used by a driver for an external transceiver (or GPIO) 649 * that detects a VBUS power session starting. Common responses include 650 * resuming the controller, activating the D+ (or D-) pullup to let the 651 * host detect that a USB device is attached, and starting to draw power 652 * (8mA or possibly more, especially after SET_CONFIGURATION). 653 * 654 * Returns zero on success, else negative errno. 655 */ 656 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget) 657 { 658 if (!gadget->ops->vbus_session) 659 return -EOPNOTSUPP; 660 return gadget->ops->vbus_session(gadget, 1); 661 } 662 663 /** 664 * usb_gadget_vbus_draw - constrain controller's VBUS power usage 665 * @gadget:The device whose VBUS usage is being described 666 * @mA:How much current to draw, in milliAmperes. This should be twice 667 * the value listed in the configuration descriptor bMaxPower field. 668 * 669 * This call is used by gadget drivers during SET_CONFIGURATION calls, 670 * reporting how much power the device may consume. For example, this 671 * could affect how quickly batteries are recharged. 672 * 673 * Returns zero on success, else negative errno. 674 */ 675 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA) 676 { 677 if (!gadget->ops->vbus_draw) 678 return -EOPNOTSUPP; 679 return gadget->ops->vbus_draw(gadget, mA); 680 } 681 682 /** 683 * usb_gadget_vbus_disconnect - notify controller about VBUS session end 684 * @gadget:the device whose VBUS supply is being described 685 * 686 * This call is used by a driver for an external transceiver (or GPIO) 687 * that detects a VBUS power session ending. Common responses include 688 * reversing everything done in usb_gadget_vbus_connect(). 689 * 690 * Returns zero on success, else negative errno. 691 */ 692 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget) 693 { 694 if (!gadget->ops->vbus_session) 695 return -EOPNOTSUPP; 696 return gadget->ops->vbus_session(gadget, 0); 697 } 698 699 /** 700 * usb_gadget_connect - software-controlled connect to USB host 701 * @gadget:the peripheral being connected 702 * 703 * Enables the D+ (or potentially D-) pullup. The host will start 704 * enumerating this gadget when the pullup is active and a VBUS session 705 * is active (the link is powered). This pullup is always enabled unless 706 * usb_gadget_disconnect() has been used to disable it. 707 * 708 * Returns zero on success, else negative errno. 709 */ 710 static inline int usb_gadget_connect(struct usb_gadget *gadget) 711 { 712 if (!gadget->ops->pullup) 713 return -EOPNOTSUPP; 714 return gadget->ops->pullup(gadget, 1); 715 } 716 717 /** 718 * usb_gadget_disconnect - software-controlled disconnect from USB host 719 * @gadget:the peripheral being disconnected 720 * 721 * Disables the D+ (or potentially D-) pullup, which the host may see 722 * as a disconnect (when a VBUS session is active). Not all systems 723 * support software pullup controls. 724 * 725 * This routine may be used during the gadget driver bind() call to prevent 726 * the peripheral from ever being visible to the USB host, unless later 727 * usb_gadget_connect() is called. For example, user mode components may 728 * need to be activated before the system can talk to hosts. 729 * 730 * Returns zero on success, else negative errno. 731 */ 732 static inline int usb_gadget_disconnect(struct usb_gadget *gadget) 733 { 734 if (!gadget->ops->pullup) 735 return -EOPNOTSUPP; 736 return gadget->ops->pullup(gadget, 0); 737 } 738 739 740 /*-------------------------------------------------------------------------*/ 741 742 /** 743 * struct usb_gadget_driver - driver for usb 'slave' devices 744 * @function: String describing the gadget's function 745 * @speed: Highest speed the driver handles. 746 * @bind: Invoked when the driver is bound to a gadget, usually 747 * after registering the driver. 748 * At that point, ep0 is fully initialized, and ep_list holds 749 * the currently-available endpoints. 750 * Called in a context that permits sleeping. 751 * @setup: Invoked for ep0 control requests that aren't handled by 752 * the hardware level driver. Most calls must be handled by 753 * the gadget driver, including descriptor and configuration 754 * management. The 16 bit members of the setup data are in 755 * USB byte order. Called in_interrupt; this may not sleep. Driver 756 * queues a response to ep0, or returns negative to stall. 757 * @disconnect: Invoked after all transfers have been stopped, 758 * when the host is disconnected. May be called in_interrupt; this 759 * may not sleep. Some devices can't detect disconnect, so this might 760 * not be called except as part of controller shutdown. 761 * @unbind: Invoked when the driver is unbound from a gadget, 762 * usually from rmmod (after a disconnect is reported). 763 * Called in a context that permits sleeping. 764 * @suspend: Invoked on USB suspend. May be called in_interrupt. 765 * @resume: Invoked on USB resume. May be called in_interrupt. 766 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers 767 * and should be called in_interrupt. 768 * 769 * Devices are disabled till a gadget driver successfully bind()s, which 770 * means the driver will handle setup() requests needed to enumerate (and 771 * meet "chapter 9" requirements) then do some useful work. 772 * 773 * If gadget->is_otg is true, the gadget driver must provide an OTG 774 * descriptor during enumeration, or else fail the bind() call. In such 775 * cases, no USB traffic may flow until both bind() returns without 776 * having called usb_gadget_disconnect(), and the USB host stack has 777 * initialized. 778 * 779 * Drivers use hardware-specific knowledge to configure the usb hardware. 780 * endpoint addressing is only one of several hardware characteristics that 781 * are in descriptors the ep0 implementation returns from setup() calls. 782 * 783 * Except for ep0 implementation, most driver code shouldn't need change to 784 * run on top of different usb controllers. It'll use endpoints set up by 785 * that ep0 implementation. 786 * 787 * The usb controller driver handles a few standard usb requests. Those 788 * include set_address, and feature flags for devices, interfaces, and 789 * endpoints (the get_status, set_feature, and clear_feature requests). 790 * 791 * Accordingly, the driver's setup() callback must always implement all 792 * get_descriptor requests, returning at least a device descriptor and 793 * a configuration descriptor. Drivers must make sure the endpoint 794 * descriptors match any hardware constraints. Some hardware also constrains 795 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3). 796 * 797 * The driver's setup() callback must also implement set_configuration, 798 * and should also implement set_interface, get_configuration, and 799 * get_interface. Setting a configuration (or interface) is where 800 * endpoints should be activated or (config 0) shut down. 801 * 802 * (Note that only the default control endpoint is supported. Neither 803 * hosts nor devices generally support control traffic except to ep0.) 804 * 805 * Most devices will ignore USB suspend/resume operations, and so will 806 * not provide those callbacks. However, some may need to change modes 807 * when the host is not longer directing those activities. For example, 808 * local controls (buttons, dials, etc) may need to be re-enabled since 809 * the (remote) host can't do that any longer; or an error state might 810 * be cleared, to make the device behave identically whether or not 811 * power is maintained. 812 */ 813 struct usb_gadget_driver { 814 char *function; 815 enum usb_device_speed speed; 816 int (*bind)(struct usb_gadget *); 817 void (*unbind)(struct usb_gadget *); 818 int (*setup)(struct usb_gadget *, 819 const struct usb_ctrlrequest *); 820 void (*disconnect)(struct usb_gadget *); 821 void (*suspend)(struct usb_gadget *); 822 void (*resume)(struct usb_gadget *); 823 void (*reset)(struct usb_gadget *); 824 }; 825 826 827 /*-------------------------------------------------------------------------*/ 828 829 /* driver modules register and unregister, as usual. 830 * these calls must be made in a context that can sleep. 831 * 832 * these will usually be implemented directly by the hardware-dependent 833 * usb bus interface driver, which will only support a single driver. 834 */ 835 836 /** 837 * usb_gadget_register_driver - register a gadget driver 838 * @driver:the driver being registered 839 * 840 * Call this in your gadget driver's module initialization function, 841 * to tell the underlying usb controller driver about your driver. 842 * The driver's bind() function will be called to bind it to a 843 * gadget before this registration call returns. It's expected that 844 * the bind() functions will be in init sections. 845 * This function must be called in a context that can sleep. 846 */ 847 int usb_gadget_register_driver(struct usb_gadget_driver *driver); 848 849 /** 850 * usb_gadget_unregister_driver - unregister a gadget driver 851 * @driver:the driver being unregistered 852 * 853 * Call this in your gadget driver's module cleanup function, 854 * to tell the underlying usb controller that your driver is 855 * going away. If the controller is connected to a USB host, 856 * it will first disconnect(). The driver is also requested 857 * to unbind() and clean up any device state, before this procedure 858 * finally returns. It's expected that the unbind() functions 859 * will in in exit sections, so may not be linked in some kernels. 860 * This function must be called in a context that can sleep. 861 */ 862 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver); 863 864 int usb_add_gadget_udc_release(struct device *parent, 865 struct usb_gadget *gadget, void (*release)(struct device *dev)); 866 int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget); 867 void usb_del_gadget_udc(struct usb_gadget *gadget); 868 /*-------------------------------------------------------------------------*/ 869 870 /* utility to simplify dealing with string descriptors */ 871 872 /** 873 * struct usb_gadget_strings - a set of USB strings in a given language 874 * @language:identifies the strings' language (0x0409 for en-us) 875 * @strings:array of strings with their ids 876 * 877 * If you're using usb_gadget_get_string(), use this to wrap all the 878 * strings for a given language. 879 */ 880 struct usb_gadget_strings { 881 u16 language; /* 0x0409 for en-us */ 882 struct usb_string *strings; 883 }; 884 885 /* put descriptor for string with that id into buf (buflen >= 256) */ 886 int usb_gadget_get_string(struct usb_gadget_strings *table, int id, u8 *buf); 887 888 /*-------------------------------------------------------------------------*/ 889 890 /* utility to simplify managing config descriptors */ 891 892 /* write vector of descriptors into buffer */ 893 int usb_descriptor_fillbuf(void *, unsigned, 894 const struct usb_descriptor_header **); 895 896 /* build config descriptor from single descriptor vector */ 897 int usb_gadget_config_buf(const struct usb_config_descriptor *config, 898 void *buf, unsigned buflen, const struct usb_descriptor_header **desc); 899 900 /*-------------------------------------------------------------------------*/ 901 /* utility to simplify map/unmap of usb_requests to/from DMA */ 902 903 extern int usb_gadget_map_request(struct usb_gadget *gadget, 904 struct usb_request *req, int is_in); 905 906 extern void usb_gadget_unmap_request(struct usb_gadget *gadget, 907 struct usb_request *req, int is_in); 908 909 /*-------------------------------------------------------------------------*/ 910 911 /* utility to set gadget state properly */ 912 913 extern void usb_gadget_set_state(struct usb_gadget *gadget, 914 enum usb_device_state state); 915 916 /*-------------------------------------------------------------------------*/ 917 918 /* utility to tell udc core that the bus reset occurs */ 919 extern void usb_gadget_udc_reset(struct usb_gadget *gadget, 920 struct usb_gadget_driver *driver); 921 922 /*-------------------------------------------------------------------------*/ 923 924 /* utility to give requests back to the gadget layer */ 925 926 extern void usb_gadget_giveback_request(struct usb_ep *ep, 927 struct usb_request *req); 928 929 /*-------------------------------------------------------------------------*/ 930 931 /* utility wrapping a simple endpoint selection policy */ 932 933 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *, 934 struct usb_endpoint_descriptor *); 935 936 extern void usb_ep_autoconfig_reset(struct usb_gadget *); 937 938 extern int usb_gadget_handle_interrupts(int index); 939 940 #endif /* __LINUX_USB_GADGET_H */ 941