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 2002-2003 by David Brownell 10 * All Rights Reserved. 11 * 12 * This software is licensed under the GNU GPL version 2. 13 * 14 * ALTERNATIVELY, the kernel API documentation which is included in this 15 * software may also be licenced under the "GNU Free Documentation 16 * License" (version 1.2 or, at your choice, any later version), when 17 * used as part of the "USB Gadget API for Linux" documentation. 18 */ 19 20#ifndef __LINUX_USB_GADGET_H 21#define __LINUX_USB_GADGET_H 22 23#ifdef __KERNEL__ 24 25struct 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 * @length: Length of that data 35 * @no_interrupt: If true, hints that no completion irq is needed. 36 * Helpful sometimes with deep request queues. 37 * @zero: If true, when writing data, makes the last packet be "short" 38 * by adding a zero length packet as needed; 39 * @short_not_ok: When reading data, makes short packets be 40 * treated as errors (queue stops advancing till cleanup). 41 * @complete: Function called when request completes 42 * @context: For use by the completion callback 43 * @list: For use by the gadget driver. 44 * @status: Reports completion code, zero or a negative errno. 45 * Normally, faults block the transfer queue from advancing until 46 * the completion callback returns. 47 * Code "-ESHUTDOWN" indicates completion caused by device disconnect, 48 * or when the driver disabled the endpoint. 49 * @actual: Reports actual bytes transferred. For reads (OUT 50 * transfers) this may be less than the requested length. If the 51 * short_not_ok flag is set, short reads are treated as errors 52 * even when status otherwise indicates successful completion. 53 * Note that for writes (IN transfers) the data bytes may still 54 * reside in a device-side FIFO. 55 * 56 * These are allocated/freed through the endpoint they're used with. The 57 * hardware's driver can add extra per-request data to the memory it returns, 58 * which often avoids separate memory allocations (potential failures), 59 * later when the request is queued. 60 * 61 * Request flags affect request handling, such as whether a zero length 62 * packet is written (the "zero" flag), whether a short read should be 63 * treated as an error (blocking request queue advance, the "short_not_ok" 64 * flag), or hinting that an interrupt is not required (the "no_interrupt" 65 * flag, for use with deep request queues). 66 * 67 * Bulk endpoints can use any size buffers, and can also be used for interrupt 68 * transfers. interrupt-only endpoints can be much less functional. 69 */ 70 // NOTE this is analagous to 'struct urb' on the host side, 71 // except that it's thinner and promotes more pre-allocation. 72 // 73 // ISSUE should this be allocated through the device? 74 75struct usb_request { 76 void *buf; 77 unsigned length; 78 dma_addr_t dma; 79 80 unsigned no_interrupt : 1, 81 zero : 1, 82 short_not_ok : 1; 83 84 void (*complete)(struct usb_ep *ep, 85 struct usb_request *req); 86 void *context; 87 struct list_head list; 88 89 int status; 90 unsigned actual; 91}; 92 93/*-------------------------------------------------------------------------*/ 94 95/* endpoint-specific parts of the api to the usb controller hardware. 96 * unlike the urb model, (de)multiplexing layers are not required. 97 * (so this api could slash overhead if used on the host side...) 98 * 99 * note that device side usb controllers commonly differ in how many 100 * endpoints they support, as well as their capabilities. 101 */ 102struct usb_ep_ops { 103 int (*enable) (struct usb_ep *ep, 104 const struct usb_endpoint_descriptor *desc); 105 int (*disable) (struct usb_ep *ep); 106 107 struct usb_request *(*alloc_request) (struct usb_ep *ep, 108 int gfp_flags); 109 void (*free_request) (struct usb_ep *ep, struct usb_request *req); 110 111 void *(*alloc_buffer) (struct usb_ep *ep, unsigned bytes, 112 dma_addr_t *dma, int gfp_flags); 113 void (*free_buffer) (struct usb_ep *ep, void *buf, dma_addr_t dma, 114 unsigned bytes); 115 // NOTE: on 2.5, drivers may also use dma_map() and 116 // dma_sync_single() to manage dma overhead. 117 118 int (*queue) (struct usb_ep *ep, struct usb_request *req, 119 int gfp_flags); 120 int (*dequeue) (struct usb_ep *ep, struct usb_request *req); 121 122 int (*set_halt) (struct usb_ep *ep, int value); 123 int (*fifo_status) (struct usb_ep *ep); 124 void (*fifo_flush) (struct usb_ep *ep); 125}; 126 127/** 128 * struct usb_ep - device side representation of USB endpoint 129 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk" 130 * @ep_list:the gadget's ep_list holds all of its endpoints 131 * @maxpacket:the maximum packet size used on this endpoint, as 132 * configured when the endpoint was enabled. 133 * @driver_data:for use by the gadget driver. all other fields are 134 * read-only to gadget drivers. 135 * 136 * the bus controller driver lists all the general purpose endpoints in 137 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list, 138 * and is accessed only in response to a driver setup() callback. 139 */ 140struct usb_ep { 141 void *driver_data; 142 143 const char *name; 144 const struct usb_ep_ops *ops; 145 struct list_head ep_list; 146 unsigned maxpacket : 16; 147}; 148 149/*-------------------------------------------------------------------------*/ 150 151/** 152 * usb_ep_enable - configure endpoint, making it usable 153 * @ep:the endpoint being configured. may not be the endpoint named "ep0". 154 * drivers discover endpoints through the ep_list of a usb_gadget. 155 * @desc:descriptor for desired behavior. caller guarantees this pointer 156 * remains valid until the endpoint is disabled; the data byte order 157 * is little-endian (usb-standard). 158 * 159 * when configurations are set, or when interface settings change, the driver 160 * will enable or disable the relevant endpoints. while it is enabled, an 161 * endpoint may be used for i/o until the driver receives a disconnect() from 162 * the host or until the endpoint is disabled. 163 * 164 * the ep0 implementation (which calls this routine) must ensure that the 165 * hardware capabilities of each endpoint match the descriptor provided 166 * for it. for example, an endpoint named "ep2in-bulk" would be usable 167 * for interrupt transfers as well as bulk, but it likely couldn't be used 168 * for iso transfers or for endpoint 14. some endpoints are fully 169 * configurable, with more generic names like "ep-a". (remember that for 170 * USB, "in" means "towards the USB master".) 171 * 172 * returns zero, or a negative error code. 173 */ 174static inline int 175usb_ep_enable (struct usb_ep *ep, const struct usb_endpoint_descriptor *desc) 176{ 177 return ep->ops->enable (ep, desc); 178} 179 180/** 181 * usb_ep_disable - endpoint is no longer usable 182 * @ep:the endpoint being unconfigured. may not be the endpoint named "ep0". 183 * 184 * no other task may be using this endpoint when this is called. 185 * any pending and uncompleted requests will complete with status 186 * indicating disconnect (-ESHUTDOWN) before this call returns. 187 * gadget drivers must call usb_ep_enable() again before queueing 188 * requests to the endpoint. 189 * 190 * returns zero, or a negative error code. 191 */ 192static inline int 193usb_ep_disable (struct usb_ep *ep) 194{ 195 return ep->ops->disable (ep); 196} 197 198/** 199 * usb_ep_alloc_request - allocate a request object to use with this endpoint 200 * @ep:the endpoint to be used with with the request 201 * @gfp_flags:GFP_* flags to use 202 * 203 * Request objects must be allocated with this call, since they normally 204 * need controller-specific setup and may even need endpoint-specific 205 * resources such as allocation of DMA descriptors. 206 * Requests may be submitted with usb_ep_queue(), and receive a single 207 * completion callback. Free requests with usb_ep_free_request(), when 208 * they are no longer needed. 209 * 210 * Returns the request, or null if one could not be allocated. 211 */ 212static inline struct usb_request * 213usb_ep_alloc_request (struct usb_ep *ep, int gfp_flags) 214{ 215 return ep->ops->alloc_request (ep, gfp_flags); 216} 217 218/** 219 * usb_ep_free_request - frees a request object 220 * @ep:the endpoint associated with the request 221 * @req:the request being freed 222 * 223 * Reverses the effect of usb_ep_alloc_request(). 224 * Caller guarantees the request is not queued, and that it will 225 * no longer be requeued (or otherwise used). 226 */ 227static inline void 228usb_ep_free_request (struct usb_ep *ep, struct usb_request *req) 229{ 230 ep->ops->free_request (ep, req); 231} 232 233/** 234 * usb_ep_alloc_buffer - allocate an I/O buffer 235 * @ep:the endpoint associated with the buffer 236 * @len:length of the desired buffer 237 * @dma:pointer to the buffer's DMA address; must be valid 238 * @gfp_flags:GFP_* flags to use 239 * 240 * Returns a new buffer, or null if one could not be allocated. 241 * The buffer is suitably aligned for dma, if that endpoint uses DMA, 242 * and the caller won't have to care about dma-inconsistency 243 * or any hidden "bounce buffer" mechanism. No additional per-request 244 * DMA mapping will be required for such buffers. 245 * Free it later with usb_ep_free_buffer(). 246 * 247 * You don't need to use this call to allocate I/O buffers unless you 248 * want to make sure drivers don't incur costs for such "bounce buffer" 249 * copies or per-request DMA mappings. 250 */ 251static inline void * 252usb_ep_alloc_buffer (struct usb_ep *ep, unsigned len, dma_addr_t *dma, 253 int gfp_flags) 254{ 255 return ep->ops->alloc_buffer (ep, len, dma, gfp_flags); 256} 257 258/** 259 * usb_ep_free_buffer - frees an i/o buffer 260 * @ep:the endpoint associated with the buffer 261 * @buf:CPU view address of the buffer 262 * @dma:the buffer's DMA address 263 * @len:length of the buffer 264 * 265 * reverses the effect of usb_ep_alloc_buffer(). 266 * caller guarantees the buffer will no longer be accessed 267 */ 268static inline void 269usb_ep_free_buffer (struct usb_ep *ep, void *buf, dma_addr_t dma, unsigned len) 270{ 271 ep->ops->free_buffer (ep, buf, dma, len); 272} 273 274/** 275 * usb_ep_queue - queues (submits) an I/O request to an endpoint. 276 * @ep:the endpoint associated with the request 277 * @req:the request being submitted 278 * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't 279 * pre-allocate all necessary memory with the request. 280 * 281 * This tells the device controller to perform the specified request through 282 * that endpoint (reading or writing a buffer). When the request completes, 283 * including being canceled by usb_ep_dequeue(), the request's completion 284 * routine is called to return the request to the driver. Any endpoint 285 * (except control endpoints like ep0) may have more than one transfer 286 * request queued; they complete in FIFO order. Once a gadget driver 287 * submits a request, that request may not be examined or modified until it 288 * is given back to that driver through the completion callback. 289 * 290 * Each request is turned into one or more packets. The controller driver 291 * never merges adjacent requests into the same packet. OUT transfers 292 * will sometimes use data that's already buffered in the hardware. 293 * 294 * Bulk endpoints can queue any amount of data; the transfer is packetized 295 * automatically. The last packet will be short if the request doesn't fill it 296 * out completely. Zero length packets (ZLPs) should be avoided in portable 297 * protocols since not all usb hardware can successfully handle zero length 298 * packets. (ZLPs may be explicitly written, and may be implicitly written if 299 * the request 'zero' flag is set.) Bulk endpoints may also be used 300 * for interrupt transfers; but the reverse is not true, and some endpoints 301 * won't support every interrupt transfer. (Such as 768 byte packets.) 302 * 303 * Interrupt-only endpoints are less functional than bulk endpoints, for 304 * example by not supporting queueing or not handling buffers that are 305 * larger than the endpoint's maxpacket size. They may also treat data 306 * toggle differently. 307 * 308 * Control endpoints ... after getting a setup() callback, the driver queues 309 * one response (optional if it would be zero length). That enables the 310 * status ack, after transfering data as specified in the response. Setup 311 * functions may return negative error codes to generate 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 * or which are enabled but halted, report errors; errors will also be 319 * reported when the usb peripheral is disconnected. 320 */ 321static inline int 322usb_ep_queue (struct usb_ep *ep, struct usb_request *req, int 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 */ 341static 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 * Returns zero, or a negative error code. On success, this call sets 357 * underlying hardware state that blocks data transfers. 358 */ 359static inline int 360usb_ep_set_halt (struct usb_ep *ep) 361{ 362 return ep->ops->set_halt (ep, 1); 363} 364 365/** 366 * usb_ep_clear_halt - clears endpoint halt, and resets toggle 367 * @ep:the bulk or interrupt endpoint being reset 368 * 369 * use this when responding to the standard usb "set interface" request, 370 * for endpoints that aren't reconfigured, after clearing any other state 371 * in the endpoint's i/o queue. 372 * 373 * returns zero, or a negative error code. on success, this call clears 374 * the underlying hardware state reflecting endpoint halt and data toggle. 375 */ 376static inline int 377usb_ep_clear_halt (struct usb_ep *ep) 378{ 379 return ep->ops->set_halt (ep, 0); 380} 381 382/** 383 * usb_ep_fifo_status - returns number of bytes in fifo, or error 384 * @ep: the endpoint whose fifo status is being checked. 385 * 386 * FIFO endpoints may have "unclaimed data" in them in certain cases, 387 * such as after aborted transfers. Hosts may not have collected all 388 * the IN data written by the gadget driver, as reported by a request 389 * completion. The gadget driver may not have collected all the data 390 * written OUT to it by the host. Drivers that need precise handling for 391 * fault reporting or recovery may need to use this call. 392 * 393 * This returns the number of such bytes in the fifo, or a negative 394 * errno if the endpoint doesn't use a FIFO or doesn't support such 395 * precise handling. 396 */ 397static inline int 398usb_ep_fifo_status (struct usb_ep *ep) 399{ 400 if (ep->ops->fifo_status) 401 return ep->ops->fifo_status (ep); 402 else 403 return -EOPNOTSUPP; 404} 405 406/** 407 * usb_ep_fifo_flush - flushes contents of a fifo 408 * @ep: the endpoint whose fifo is being flushed. 409 * 410 * This call may be used to flush the "unclaimed data" that may exist in 411 * an endpoint fifo after abnormal transaction terminations. The call 412 * must never be used except when endpoint is not being used for any 413 * protocol translation. 414 */ 415static inline void 416usb_ep_fifo_flush (struct usb_ep *ep) 417{ 418 if (ep->ops->fifo_flush) 419 ep->ops->fifo_flush (ep); 420} 421 422 423/*-------------------------------------------------------------------------*/ 424 425struct usb_gadget; 426 427/* the rest of the api to the controller hardware: device operations, 428 * which don't involve endpoints (or i/o). 429 */ 430struct usb_gadget_ops { 431 int (*get_frame)(struct usb_gadget *); 432 int (*wakeup)(struct usb_gadget *); 433 int (*set_selfpowered) (struct usb_gadget *, int value); 434 int (*ioctl)(struct usb_gadget *, 435 unsigned code, unsigned long param); 436}; 437 438/** 439 * struct usb_gadget - represents a usb slave device 440 * @ep0: Endpoint zero, used when reading or writing responses to 441 * driver setup() requests 442 * @ep_list: List of other endpoints supported by the device. 443 * @speed: Speed of current connection to USB host. 444 * @name: Identifies the controller hardware type. Used in diagnostics 445 * and sometimes configuration. 446 * 447 * Gadgets have a mostly-portable "gadget driver" implementing device 448 * functions, handling all usb configurations and interfaces. They 449 * also have a hardware-specific driver (accessed through ops vectors), 450 * which insulates the gadget driver from hardware details and packages 451 * the hardware endpoints through generic i/o queues. 452 * 453 * Except for the driver data, all fields in this structure are 454 * read-only to the gadget driver. That driver data is part of the 455 * "driver model" infrastructure in 2.5 (and later) kernels, and for 456 * earlier systems is grouped in a similar structure that's not known 457 * to the rest of the kernel. 458 */ 459struct usb_gadget { 460 /* readonly to gadget driver */ 461 const struct usb_gadget_ops *ops; 462 struct usb_ep *ep0; 463 struct list_head ep_list; /* of usb_ep */ 464 enum usb_device_speed speed; 465 const char *name; 466 467 struct __gadget_device { 468 const char *bus_id; 469 void *driver_data; 470 } dev; 471}; 472 473static inline void set_gadget_data (struct usb_gadget *gadget, void *data) 474 { gadget->dev.driver_data = data; } 475static inline void *get_gadget_data (struct usb_gadget *gadget) 476 { return gadget->dev.driver_data; } 477 478 479/* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */ 480#define gadget_for_each_ep(tmp,gadget) \ 481 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list) 482 483#ifndef list_for_each_entry 484/* not available in 2.4.18 */ 485#define list_for_each_entry(pos, head, member) \ 486 for (pos = list_entry((head)->next, typeof(*pos), member), \ 487 prefetch(pos->member.next); \ 488 &pos->member != (head); \ 489 pos = list_entry(pos->member.next, typeof(*pos), member), \ 490 prefetch(pos->member.next)) 491#endif 492 493 494/** 495 * usb_gadget_frame_number - returns the current frame number 496 * @gadget: controller that reports the frame number 497 * 498 * Returns the usb frame number, normally eleven bits from a SOF packet, 499 * or negative errno if this device doesn't support this capability. 500 */ 501static inline int usb_gadget_frame_number (struct usb_gadget *gadget) 502{ 503 return gadget->ops->get_frame (gadget); 504} 505 506/** 507 * usb_gadget_wakeup - tries to wake up the host connected to this gadget 508 * @gadget: controller used to wake up the host 509 * 510 * Returns zero on success, else negative error code if the hardware 511 * doesn't support such attempts, or its support has not been enabled 512 * by the usb host. Drivers must return device descriptors that report 513 * their ability to support this, or hosts won't enable it. 514 */ 515static inline int usb_gadget_wakeup (struct usb_gadget *gadget) 516{ 517 if (!gadget->ops->wakeup) 518 return -EOPNOTSUPP; 519 return gadget->ops->wakeup (gadget); 520} 521 522/** 523 * usb_gadget_set_selfpowered - sets the device selfpowered feature. 524 * @gadget:the device being declared as self-powered 525 * 526 * this affects the device status reported by the hardware driver 527 * to reflect that it now has a local power supply. 528 * 529 * returns zero on success, else negative errno. 530 */ 531static inline int 532usb_gadget_set_selfpowered (struct usb_gadget *gadget) 533{ 534 if (!gadget->ops->set_selfpowered) 535 return -EOPNOTSUPP; 536 return gadget->ops->set_selfpowered (gadget, 1); 537} 538 539/** 540 * usb_gadget_clear_selfpowered - clear the device selfpowered feature. 541 * @gadget:the device being declared as bus-powered 542 * 543 * this affects the device status reported by the hardware driver. 544 * some hardware may not support bus-powered operation, in which 545 * case this feature's value can never change. 546 * 547 * returns zero on success, else negative errno. 548 */ 549static inline int 550usb_gadget_clear_selfpowered (struct usb_gadget *gadget) 551{ 552 if (!gadget->ops->set_selfpowered) 553 return -EOPNOTSUPP; 554 return gadget->ops->set_selfpowered (gadget, 0); 555} 556 557 558/*-------------------------------------------------------------------------*/ 559 560/** 561 * struct usb_gadget_driver - driver for usb 'slave' devices 562 * @function: String describing the gadget's function 563 * @speed: Highest speed the driver handles. 564 * @bind: Invoked when the driver is bound to a gadget, usually 565 * after registering the driver. 566 * At that point, ep0 is fully initialized, and ep_list holds 567 * the currently-available endpoints. 568 * Called in a context that permits sleeping. 569 * @setup: Invoked for ep0 control requests that aren't handled by 570 * the hardware level driver. Most calls must be handled by 571 * the gadget driver, including descriptor and configuration 572 * management. The 16 bit members of the setup data are in 573 * cpu order. Called in_interrupt; this may not sleep. Driver 574 * queues a response to ep0, or returns negative to stall. 575 * @disconnect: Invoked after all transfers have been stopped, 576 * when the host is disconnected. May be called in_interrupt; this 577 * may not sleep. 578 * @unbind: Invoked when the driver is unbound from a gadget, 579 * usually from rmmod (after a disconnect is reported). 580 * Called in a context that permits sleeping. 581 * @suspend: Invoked on USB suspend. May be called in_interrupt. 582 * @resume: Invoked on USB resume. May be called in_interrupt. 583 * 584 * Devices are disabled till a gadget driver successfully bind()s, which 585 * means the driver will handle setup() requests needed to enumerate (and 586 * meet "chapter 9" requirements) then do some useful work. 587 * 588 * Drivers use hardware-specific knowledge to configure the usb hardware. 589 * endpoint addressing is only one of several hardware characteristics that 590 * are in descriptors the ep0 implementation returns from setup() calls. 591 * 592 * Except for ep0 implementation, most driver code shouldn't need change to 593 * run on top of different usb controllers. It'll use endpoints set up by 594 * that ep0 implementation. 595 * 596 * The usb controller driver handles a few standard usb requests. Those 597 * include set_address, and feature flags for devices, interfaces, and 598 * endpoints (the get_status, set_feature, and clear_feature requests). 599 * 600 * Accordingly, the driver's setup() callback must always implement all 601 * get_descriptor requests, returning at least a device descriptor and 602 * a configuration descriptor. Drivers must make sure the endpoint 603 * descriptors match any hardware constraints. Some hardware also constrains 604 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3). 605 * 606 * The driver's setup() callback must also implement set_configuration, 607 * and should also implement set_interface, get_configuration, and 608 * get_interface. Setting a configuration (or interface) is where 609 * endpoints should be activated or (config 0) shut down. 610 * 611 * (Note that only the default control endpoint is supported. Neither 612 * hosts nor devices generally support control traffic except to ep0.) 613 * 614 * Most devices will ignore USB suspend/resume operations, and so will 615 * not provide those callbacks. However, some may need to change modes 616 * when the host is not longer directing those activities. For example, 617 * local controls (buttons, dials, etc) may need to be re-enabled since 618 * the (remote) host can't do that any longer. 619 */ 620struct usb_gadget_driver { 621 char *function; 622 enum usb_device_speed speed; 623 int (*bind)(struct usb_gadget *); 624 void (*unbind)(struct usb_gadget *); 625 int (*setup)(struct usb_gadget *, 626 const struct usb_ctrlrequest *); 627 void (*disconnect)(struct usb_gadget *); 628 void (*suspend)(struct usb_gadget *); 629 void (*resume)(struct usb_gadget *); 630 631 // FIXME support safe rmmod 632 struct __gadget_driver { 633 const char *name; 634 void *driver_data; 635 } driver; 636}; 637 638 639 640/*-------------------------------------------------------------------------*/ 641 642/* driver modules register and unregister, as usual. 643 * these calls must be made in a context that can sleep. 644 * 645 * these will usually be implemented directly by the hardware-dependent 646 * usb bus interface driver, which will only support a single driver. 647 */ 648 649/** 650 * usb_gadget_register_driver - register a gadget driver 651 * @driver:the driver being registered 652 * 653 * Call this in your gadget driver's module initialization function, 654 * to tell the underlying usb controller driver about your driver. 655 * The driver's bind() function will be called to bind it to a 656 * gadget. This function must be called in a context that can sleep. 657 */ 658int usb_gadget_register_driver (struct usb_gadget_driver *driver); 659 660/** 661 * usb_gadget_unregister_driver - unregister a gadget driver 662 * @driver:the driver being unregistered 663 * 664 * Call this in your gadget driver's module cleanup function, 665 * to tell the underlying usb controller that your driver is 666 * going away. If the controller is connected to a USB host, 667 * it will first disconnect(). The driver is also requested 668 * to unbind() and clean up any device state, before this procedure 669 * finally returns. 670 * This function must be called in a context that can sleep. 671 */ 672int usb_gadget_unregister_driver (struct usb_gadget_driver *driver); 673 674/*-------------------------------------------------------------------------*/ 675 676/* utility to simplify dealing with string descriptors */ 677 678/** 679 * struct usb_string - wraps a C string and its USB id 680 * @id:the (nonzero) ID for this string 681 * @s:the string, in ISO-8859/1 characters 682 * 683 * If you're using usb_gadget_get_string(), use this to wrap a string 684 * together with its ID. 685 */ 686struct usb_string { 687 u8 id; 688 const char *s; 689}; 690 691/** 692 * struct usb_gadget_strings - a set of USB strings in a given language 693 * @language:identifies the strings' language (0x0409 for en-us) 694 * @strings:array of strings with their ids 695 * 696 * If you're using usb_gadget_get_string(), use this to wrap all the 697 * strings for a given language. 698 */ 699struct usb_gadget_strings { 700 u16 language; /* 0x0409 for en-us */ 701 struct usb_string *strings; 702}; 703 704/* put descriptor for string with that id into buf (buflen >= 256) */ 705int usb_gadget_get_string (struct usb_gadget_strings *table, int id, u8 *buf); 706 707 708#endif /* __KERNEL__ */ 709 710#endif /* __LINUX_USB_GADGET_H */ 711