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 15#ifndef __LINUX_USB_GADGET_H 16#define __LINUX_USB_GADGET_H 17 18#include <linux/device.h> 19#include <linux/errno.h> 20#include <linux/init.h> 21#include <linux/list.h> 22#include <linux/slab.h> 23#include <linux/scatterlist.h> 24#include <linux/types.h> 25#include <linux/workqueue.h> 26#include <linux/usb/ch9.h> 27 28struct usb_ep; 29 30/** 31 * struct usb_request - describes one i/o request 32 * @buf: Buffer used for data. Always provide this; some controllers 33 * only use PIO, or don't use DMA for some endpoints. 34 * @dma: DMA address corresponding to 'buf'. If you don't set this 35 * field, and the usb controller needs one, it is responsible 36 * for mapping and unmapping the buffer. 37 * @sg: a scatterlist for SG-capable controllers. 38 * @num_sgs: number of SG entries 39 * @num_mapped_sgs: number of SG entries mapped to DMA (internal) 40 * @length: Length of that data 41 * @stream_id: The stream id, when USB3.0 bulk streams are being used 42 * @no_interrupt: If true, hints that no completion irq is needed. 43 * Helpful sometimes with deep request queues that are handled 44 * directly by DMA controllers. 45 * @zero: If true, when writing data, makes the last packet be "short" 46 * by adding a zero length packet as needed; 47 * @short_not_ok: When reading data, makes short packets be 48 * treated as errors (queue stops advancing till cleanup). 49 * @complete: Function called when request completes, so this request and 50 * its buffer may be re-used. The function will always be called with 51 * interrupts disabled, and it must not sleep. 52 * Reads terminate with a short packet, or when the buffer fills, 53 * whichever comes first. When writes terminate, some data bytes 54 * will usually still be in flight (often in a hardware fifo). 55 * Errors (for reads or writes) stop the queue from advancing 56 * until the completion function returns, so that any transfers 57 * invalidated by the error may first be dequeued. 58 * @context: For use by the completion callback 59 * @list: For use by the gadget driver. 60 * @status: Reports completion code, zero or a negative errno. 61 * Normally, faults block the transfer queue from advancing until 62 * the completion callback returns. 63 * Code "-ESHUTDOWN" indicates completion caused by device disconnect, 64 * or when the driver disabled the endpoint. 65 * @actual: Reports bytes transferred to/from the buffer. For reads (OUT 66 * transfers) this may be less than the requested length. If the 67 * short_not_ok flag is set, short reads are treated as errors 68 * even when status otherwise indicates successful completion. 69 * Note that for writes (IN transfers) some data bytes may still 70 * reside in a device-side FIFO when the request is reported as 71 * complete. 72 * 73 * These are allocated/freed through the endpoint they're used with. The 74 * hardware's driver can add extra per-request data to the memory it returns, 75 * which often avoids separate memory allocations (potential failures), 76 * later when the request is queued. 77 * 78 * Request flags affect request handling, such as whether a zero length 79 * packet is written (the "zero" flag), whether a short read should be 80 * treated as an error (blocking request queue advance, the "short_not_ok" 81 * flag), or hinting that an interrupt is not required (the "no_interrupt" 82 * flag, for use with deep request queues). 83 * 84 * Bulk endpoints can use any size buffers, and can also be used for interrupt 85 * transfers. interrupt-only endpoints can be much less functional. 86 * 87 * NOTE: this is analogous to 'struct urb' on the host side, except that 88 * it's thinner and promotes more pre-allocation. 89 */ 90 91struct usb_request { 92 void *buf; 93 unsigned length; 94 dma_addr_t dma; 95 96 struct scatterlist *sg; 97 unsigned num_sgs; 98 unsigned num_mapped_sgs; 99 100 unsigned stream_id:16; 101 unsigned no_interrupt:1; 102 unsigned zero:1; 103 unsigned short_not_ok:1; 104 105 void (*complete)(struct usb_ep *ep, 106 struct usb_request *req); 107 void *context; 108 struct list_head list; 109 110 int status; 111 unsigned actual; 112}; 113 114/*-------------------------------------------------------------------------*/ 115 116/* endpoint-specific parts of the api to the usb controller hardware. 117 * unlike the urb model, (de)multiplexing layers are not required. 118 * (so this api could slash overhead if used on the host side...) 119 * 120 * note that device side usb controllers commonly differ in how many 121 * endpoints they support, as well as their capabilities. 122 */ 123struct usb_ep_ops { 124 int (*enable) (struct usb_ep *ep, 125 const struct usb_endpoint_descriptor *desc); 126 int (*disable) (struct usb_ep *ep); 127 128 struct usb_request *(*alloc_request) (struct usb_ep *ep, 129 gfp_t gfp_flags); 130 void (*free_request) (struct usb_ep *ep, struct usb_request *req); 131 132 int (*queue) (struct usb_ep *ep, struct usb_request *req, 133 gfp_t gfp_flags); 134 int (*dequeue) (struct usb_ep *ep, struct usb_request *req); 135 136 int (*set_halt) (struct usb_ep *ep, int value); 137 int (*set_wedge) (struct usb_ep *ep); 138 139 int (*fifo_status) (struct usb_ep *ep); 140 void (*fifo_flush) (struct usb_ep *ep); 141}; 142 143/** 144 * struct usb_ep - device side representation of USB endpoint 145 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk" 146 * @ops: Function pointers used to access hardware-specific operations. 147 * @ep_list:the gadget's ep_list holds all of its endpoints 148 * @maxpacket:The maximum packet size used on this endpoint. The initial 149 * value can sometimes be reduced (hardware allowing), according to 150 * the endpoint descriptor used to configure the endpoint. 151 * @maxpacket_limit:The maximum packet size value which can be handled by this 152 * endpoint. It's set once by UDC driver when endpoint is initialized, and 153 * should not be changed. Should not be confused with maxpacket. 154 * @max_streams: The maximum number of streams supported 155 * by this EP (0 - 16, actual number is 2^n) 156 * @mult: multiplier, 'mult' value for SS Isoc EPs 157 * @maxburst: the maximum number of bursts supported by this EP (for usb3) 158 * @driver_data:for use by the gadget driver. 159 * @address: used to identify the endpoint when finding descriptor that 160 * matches connection speed 161 * @desc: endpoint descriptor. This pointer is set before the endpoint is 162 * enabled and remains valid until the endpoint is disabled. 163 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion 164 * descriptor that is used to configure the endpoint 165 * 166 * the bus controller driver lists all the general purpose endpoints in 167 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list, 168 * and is accessed only in response to a driver setup() callback. 169 */ 170struct usb_ep { 171 void *driver_data; 172 173 const char *name; 174 const struct usb_ep_ops *ops; 175 struct list_head ep_list; 176 unsigned maxpacket:16; 177 unsigned maxpacket_limit:16; 178 unsigned max_streams:16; 179 unsigned mult:2; 180 unsigned maxburst:5; 181 u8 address; 182 const struct usb_endpoint_descriptor *desc; 183 const struct usb_ss_ep_comp_descriptor *comp_desc; 184}; 185 186/*-------------------------------------------------------------------------*/ 187 188/** 189 * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint 190 * @ep:the endpoint being configured 191 * @maxpacket_limit:value of maximum packet size limit 192 * 193 * This function should be used only in UDC drivers to initialize endpoint 194 * (usually in probe function). 195 */ 196static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep, 197 unsigned maxpacket_limit) 198{ 199 ep->maxpacket_limit = maxpacket_limit; 200 ep->maxpacket = maxpacket_limit; 201} 202 203/** 204 * usb_ep_enable - configure endpoint, making it usable 205 * @ep:the endpoint being configured. may not be the endpoint named "ep0". 206 * drivers discover endpoints through the ep_list of a usb_gadget. 207 * 208 * When configurations are set, or when interface settings change, the driver 209 * will enable or disable the relevant endpoints. while it is enabled, an 210 * endpoint may be used for i/o until the driver receives a disconnect() from 211 * the host or until the endpoint is disabled. 212 * 213 * the ep0 implementation (which calls this routine) must ensure that the 214 * hardware capabilities of each endpoint match the descriptor provided 215 * for it. for example, an endpoint named "ep2in-bulk" would be usable 216 * for interrupt transfers as well as bulk, but it likely couldn't be used 217 * for iso transfers or for endpoint 14. some endpoints are fully 218 * configurable, with more generic names like "ep-a". (remember that for 219 * USB, "in" means "towards the USB master".) 220 * 221 * returns zero, or a negative error code. 222 */ 223static inline int usb_ep_enable(struct usb_ep *ep) 224{ 225 return ep->ops->enable(ep, ep->desc); 226} 227 228/** 229 * usb_ep_disable - endpoint is no longer usable 230 * @ep:the endpoint being unconfigured. may not be the endpoint named "ep0". 231 * 232 * no other task may be using this endpoint when this is called. 233 * any pending and uncompleted requests will complete with status 234 * indicating disconnect (-ESHUTDOWN) before this call returns. 235 * gadget drivers must call usb_ep_enable() again before queueing 236 * requests to the endpoint. 237 * 238 * returns zero, or a negative error code. 239 */ 240static inline int usb_ep_disable(struct usb_ep *ep) 241{ 242 return ep->ops->disable(ep); 243} 244 245/** 246 * usb_ep_alloc_request - allocate a request object to use with this endpoint 247 * @ep:the endpoint to be used with with the request 248 * @gfp_flags:GFP_* flags to use 249 * 250 * Request objects must be allocated with this call, since they normally 251 * need controller-specific setup and may even need endpoint-specific 252 * resources such as allocation of DMA descriptors. 253 * Requests may be submitted with usb_ep_queue(), and receive a single 254 * completion callback. Free requests with usb_ep_free_request(), when 255 * they are no longer needed. 256 * 257 * Returns the request, or null if one could not be allocated. 258 */ 259static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, 260 gfp_t gfp_flags) 261{ 262 return ep->ops->alloc_request(ep, gfp_flags); 263} 264 265/** 266 * usb_ep_free_request - frees a request object 267 * @ep:the endpoint associated with the request 268 * @req:the request being freed 269 * 270 * Reverses the effect of usb_ep_alloc_request(). 271 * Caller guarantees the request is not queued, and that it will 272 * no longer be requeued (or otherwise used). 273 */ 274static inline void usb_ep_free_request(struct usb_ep *ep, 275 struct usb_request *req) 276{ 277 ep->ops->free_request(ep, req); 278} 279 280/** 281 * usb_ep_queue - queues (submits) an I/O request to an endpoint. 282 * @ep:the endpoint associated with the request 283 * @req:the request being submitted 284 * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't 285 * pre-allocate all necessary memory with the request. 286 * 287 * This tells the device controller to perform the specified request through 288 * that endpoint (reading or writing a buffer). When the request completes, 289 * including being canceled by usb_ep_dequeue(), the request's completion 290 * routine is called to return the request to the driver. Any endpoint 291 * (except control endpoints like ep0) may have more than one transfer 292 * request queued; they complete in FIFO order. Once a gadget driver 293 * submits a request, that request may not be examined or modified until it 294 * is given back to that driver through the completion callback. 295 * 296 * Each request is turned into one or more packets. The controller driver 297 * never merges adjacent requests into the same packet. OUT transfers 298 * will sometimes use data that's already buffered in the hardware. 299 * Drivers can rely on the fact that the first byte of the request's buffer 300 * always corresponds to the first byte of some USB packet, for both 301 * IN and OUT transfers. 302 * 303 * Bulk endpoints can queue any amount of data; the transfer is packetized 304 * automatically. The last packet will be short if the request doesn't fill it 305 * out completely. Zero length packets (ZLPs) should be avoided in portable 306 * protocols since not all usb hardware can successfully handle zero length 307 * packets. (ZLPs may be explicitly written, and may be implicitly written if 308 * the request 'zero' flag is set.) Bulk endpoints may also be used 309 * for interrupt transfers; but the reverse is not true, and some endpoints 310 * won't support every interrupt transfer. (Such as 768 byte packets.) 311 * 312 * Interrupt-only endpoints are less functional than bulk endpoints, for 313 * example by not supporting queueing or not handling buffers that are 314 * larger than the endpoint's maxpacket size. They may also treat data 315 * toggle differently. 316 * 317 * Control endpoints ... after getting a setup() callback, the driver queues 318 * one response (even if it would be zero length). That enables the 319 * status ack, after transferring data as specified in the response. Setup 320 * functions may return negative error codes to generate protocol stalls. 321 * (Note that some USB device controllers disallow protocol stall responses 322 * in some cases.) When control responses are deferred (the response is 323 * written after the setup callback returns), then usb_ep_set_halt() may be 324 * used on ep0 to trigger protocol stalls. Depending on the controller, 325 * it may not be possible to trigger a status-stage protocol stall when the 326 * data stage is over, that is, from within the response's completion 327 * routine. 328 * 329 * For periodic endpoints, like interrupt or isochronous ones, the usb host 330 * arranges to poll once per interval, and the gadget driver usually will 331 * have queued some data to transfer at that time. 332 * 333 * Returns zero, or a negative error code. Endpoints that are not enabled 334 * report errors; errors will also be 335 * reported when the usb peripheral is disconnected. 336 */ 337static inline int usb_ep_queue(struct usb_ep *ep, 338 struct usb_request *req, gfp_t gfp_flags) 339{ 340 return ep->ops->queue(ep, req, gfp_flags); 341} 342 343/** 344 * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint 345 * @ep:the endpoint associated with the request 346 * @req:the request being canceled 347 * 348 * If the request is still active on the endpoint, it is dequeued and its 349 * completion routine is called (with status -ECONNRESET); else a negative 350 * error code is returned. This is guaranteed to happen before the call to 351 * usb_ep_dequeue() returns. 352 * 353 * Note that some hardware can't clear out write fifos (to unlink the request 354 * at the head of the queue) except as part of disconnecting from usb. Such 355 * restrictions prevent drivers from supporting configuration changes, 356 * even to configuration zero (a "chapter 9" requirement). 357 */ 358static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req) 359{ 360 return ep->ops->dequeue(ep, req); 361} 362 363/** 364 * usb_ep_set_halt - sets the endpoint halt feature. 365 * @ep: the non-isochronous endpoint being stalled 366 * 367 * Use this to stall an endpoint, perhaps as an error report. 368 * Except for control endpoints, 369 * the endpoint stays halted (will not stream any data) until the host 370 * clears this feature; drivers may need to empty the endpoint's request 371 * queue first, to make sure no inappropriate transfers happen. 372 * 373 * Note that while an endpoint CLEAR_FEATURE will be invisible to the 374 * gadget driver, a SET_INTERFACE will not be. To reset endpoints for the 375 * current altsetting, see usb_ep_clear_halt(). When switching altsettings, 376 * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints. 377 * 378 * Returns zero, or a negative error code. On success, this call sets 379 * underlying hardware state that blocks data transfers. 380 * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any 381 * transfer requests are still queued, or if the controller hardware 382 * (usually a FIFO) still holds bytes that the host hasn't collected. 383 */ 384static inline int usb_ep_set_halt(struct usb_ep *ep) 385{ 386 return ep->ops->set_halt(ep, 1); 387} 388 389/** 390 * usb_ep_clear_halt - clears endpoint halt, and resets toggle 391 * @ep:the bulk or interrupt endpoint being reset 392 * 393 * Use this when responding to the standard usb "set interface" request, 394 * for endpoints that aren't reconfigured, after clearing any other state 395 * in the endpoint's i/o queue. 396 * 397 * Returns zero, or a negative error code. On success, this call clears 398 * the underlying hardware state reflecting endpoint halt and data toggle. 399 * Note that some hardware can't support this request (like pxa2xx_udc), 400 * and accordingly can't correctly implement interface altsettings. 401 */ 402static inline int usb_ep_clear_halt(struct usb_ep *ep) 403{ 404 return ep->ops->set_halt(ep, 0); 405} 406 407/** 408 * usb_ep_set_wedge - sets the halt feature and ignores clear requests 409 * @ep: the endpoint being wedged 410 * 411 * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT) 412 * requests. If the gadget driver clears the halt status, it will 413 * automatically unwedge the endpoint. 414 * 415 * Returns zero on success, else negative errno. 416 */ 417static inline int 418usb_ep_set_wedge(struct usb_ep *ep) 419{ 420 if (ep->ops->set_wedge) 421 return ep->ops->set_wedge(ep); 422 else 423 return ep->ops->set_halt(ep, 1); 424} 425 426/** 427 * usb_ep_fifo_status - returns number of bytes in fifo, or error 428 * @ep: the endpoint whose fifo status is being checked. 429 * 430 * FIFO endpoints may have "unclaimed data" in them in certain cases, 431 * such as after aborted transfers. Hosts may not have collected all 432 * the IN data written by the gadget driver (and reported by a request 433 * completion). The gadget driver may not have collected all the data 434 * written OUT to it by the host. Drivers that need precise handling for 435 * fault reporting or recovery may need to use this call. 436 * 437 * This returns the number of such bytes in the fifo, or a negative 438 * errno if the endpoint doesn't use a FIFO or doesn't support such 439 * precise handling. 440 */ 441static inline int usb_ep_fifo_status(struct usb_ep *ep) 442{ 443 if (ep->ops->fifo_status) 444 return ep->ops->fifo_status(ep); 445 else 446 return -EOPNOTSUPP; 447} 448 449/** 450 * usb_ep_fifo_flush - flushes contents of a fifo 451 * @ep: the endpoint whose fifo is being flushed. 452 * 453 * This call may be used to flush the "unclaimed data" that may exist in 454 * an endpoint fifo after abnormal transaction terminations. The call 455 * must never be used except when endpoint is not being used for any 456 * protocol translation. 457 */ 458static inline void usb_ep_fifo_flush(struct usb_ep *ep) 459{ 460 if (ep->ops->fifo_flush) 461 ep->ops->fifo_flush(ep); 462} 463 464 465/*-------------------------------------------------------------------------*/ 466 467struct usb_dcd_config_params { 468 __u8 bU1devExitLat; /* U1 Device exit Latency */ 469#define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */ 470 __le16 bU2DevExitLat; /* U2 Device exit Latency */ 471#define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */ 472}; 473 474 475struct usb_gadget; 476struct usb_gadget_driver; 477struct usb_udc; 478 479/* the rest of the api to the controller hardware: device operations, 480 * which don't involve endpoints (or i/o). 481 */ 482struct usb_gadget_ops { 483 int (*get_frame)(struct usb_gadget *); 484 int (*wakeup)(struct usb_gadget *); 485 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered); 486 int (*vbus_session) (struct usb_gadget *, int is_active); 487 int (*vbus_draw) (struct usb_gadget *, unsigned mA); 488 int (*pullup) (struct usb_gadget *, int is_on); 489 int (*ioctl)(struct usb_gadget *, 490 unsigned code, unsigned long param); 491 void (*get_config_params)(struct usb_dcd_config_params *); 492 int (*udc_start)(struct usb_gadget *, 493 struct usb_gadget_driver *); 494 int (*udc_stop)(struct usb_gadget *); 495}; 496 497/** 498 * struct usb_gadget - represents a usb slave device 499 * @work: (internal use) Workqueue to be used for sysfs_notify() 500 * @udc: struct usb_udc pointer for this gadget 501 * @ops: Function pointers used to access hardware-specific operations. 502 * @ep0: Endpoint zero, used when reading or writing responses to 503 * driver setup() requests 504 * @ep_list: List of other endpoints supported by the device. 505 * @speed: Speed of current connection to USB host. 506 * @max_speed: Maximal speed the UDC can handle. UDC must support this 507 * and all slower speeds. 508 * @state: the state we are now (attached, suspended, configured, etc) 509 * @name: Identifies the controller hardware type. Used in diagnostics 510 * and sometimes configuration. 511 * @dev: Driver model state for this abstract device. 512 * @out_epnum: last used out ep number 513 * @in_epnum: last used in ep number 514 * @sg_supported: true if we can handle scatter-gather 515 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the 516 * gadget driver must provide a USB OTG descriptor. 517 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable 518 * is in the Mini-AB jack, and HNP has been used to switch roles 519 * so that the "A" device currently acts as A-Peripheral, not A-Host. 520 * @a_hnp_support: OTG device feature flag, indicating that the A-Host 521 * supports HNP at this port. 522 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host 523 * only supports HNP on a different root port. 524 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host 525 * enabled HNP support. 526 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to 527 * MaxPacketSize. 528 * @is_selfpowered: if the gadget is self-powered. 529 * 530 * Gadgets have a mostly-portable "gadget driver" implementing device 531 * functions, handling all usb configurations and interfaces. Gadget 532 * drivers talk to hardware-specific code indirectly, through ops vectors. 533 * That insulates the gadget driver from hardware details, and packages 534 * the hardware endpoints through generic i/o queues. The "usb_gadget" 535 * and "usb_ep" interfaces provide that insulation from the hardware. 536 * 537 * Except for the driver data, all fields in this structure are 538 * read-only to the gadget driver. That driver data is part of the 539 * "driver model" infrastructure in 2.6 (and later) kernels, and for 540 * earlier systems is grouped in a similar structure that's not known 541 * to the rest of the kernel. 542 * 543 * Values of the three OTG device feature flags are updated before the 544 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before 545 * driver suspend() calls. They are valid only when is_otg, and when the 546 * device is acting as a B-Peripheral (so is_a_peripheral is false). 547 */ 548struct usb_gadget { 549 struct work_struct work; 550 struct usb_udc *udc; 551 /* readonly to gadget driver */ 552 const struct usb_gadget_ops *ops; 553 struct usb_ep *ep0; 554 struct list_head ep_list; /* of usb_ep */ 555 enum usb_device_speed speed; 556 enum usb_device_speed max_speed; 557 enum usb_device_state state; 558 const char *name; 559 struct device dev; 560 unsigned out_epnum; 561 unsigned in_epnum; 562 563 unsigned sg_supported:1; 564 unsigned is_otg:1; 565 unsigned is_a_peripheral:1; 566 unsigned b_hnp_enable:1; 567 unsigned a_hnp_support:1; 568 unsigned a_alt_hnp_support:1; 569 unsigned quirk_ep_out_aligned_size:1; 570 unsigned is_selfpowered:1; 571}; 572#define work_to_gadget(w) (container_of((w), struct usb_gadget, work)) 573 574static inline void set_gadget_data(struct usb_gadget *gadget, void *data) 575 { dev_set_drvdata(&gadget->dev, data); } 576static inline void *get_gadget_data(struct usb_gadget *gadget) 577 { return dev_get_drvdata(&gadget->dev); } 578static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev) 579{ 580 return container_of(dev, struct usb_gadget, dev); 581} 582 583/* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */ 584#define gadget_for_each_ep(tmp, gadget) \ 585 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list) 586 587 588/** 589 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget 590 * requires quirk_ep_out_aligned_size, otherwise reguens len. 591 * @g: controller to check for quirk 592 * @ep: the endpoint whose maxpacketsize is used to align @len 593 * @len: buffer size's length to align to @ep's maxpacketsize 594 * 595 * This helper is used in case it's required for any reason to check and maybe 596 * align buffer's size to an ep's maxpacketsize. 597 */ 598static inline size_t 599usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len) 600{ 601 return !g->quirk_ep_out_aligned_size ? len : 602 round_up(len, (size_t)ep->desc->wMaxPacketSize); 603} 604 605/** 606 * gadget_is_dualspeed - return true iff the hardware handles high speed 607 * @g: controller that might support both high and full speeds 608 */ 609static inline int gadget_is_dualspeed(struct usb_gadget *g) 610{ 611 return g->max_speed >= USB_SPEED_HIGH; 612} 613 614/** 615 * gadget_is_superspeed() - return true if the hardware handles superspeed 616 * @g: controller that might support superspeed 617 */ 618static inline int gadget_is_superspeed(struct usb_gadget *g) 619{ 620 return g->max_speed >= USB_SPEED_SUPER; 621} 622 623/** 624 * gadget_is_otg - return true iff the hardware is OTG-ready 625 * @g: controller that might have a Mini-AB connector 626 * 627 * This is a runtime test, since kernels with a USB-OTG stack sometimes 628 * run on boards which only have a Mini-B (or Mini-A) connector. 629 */ 630static inline int gadget_is_otg(struct usb_gadget *g) 631{ 632#ifdef CONFIG_USB_OTG 633 return g->is_otg; 634#else 635 return 0; 636#endif 637} 638 639/** 640 * usb_gadget_frame_number - returns the current frame number 641 * @gadget: controller that reports the frame number 642 * 643 * Returns the usb frame number, normally eleven bits from a SOF packet, 644 * or negative errno if this device doesn't support this capability. 645 */ 646static inline int usb_gadget_frame_number(struct usb_gadget *gadget) 647{ 648 return gadget->ops->get_frame(gadget); 649} 650 651/** 652 * usb_gadget_wakeup - tries to wake up the host connected to this gadget 653 * @gadget: controller used to wake up the host 654 * 655 * Returns zero on success, else negative error code if the hardware 656 * doesn't support such attempts, or its support has not been enabled 657 * by the usb host. Drivers must return device descriptors that report 658 * their ability to support this, or hosts won't enable it. 659 * 660 * This may also try to use SRP to wake the host and start enumeration, 661 * even if OTG isn't otherwise in use. OTG devices may also start 662 * remote wakeup even when hosts don't explicitly enable it. 663 */ 664static inline int usb_gadget_wakeup(struct usb_gadget *gadget) 665{ 666 if (!gadget->ops->wakeup) 667 return -EOPNOTSUPP; 668 return gadget->ops->wakeup(gadget); 669} 670 671/** 672 * usb_gadget_set_selfpowered - sets the device selfpowered feature. 673 * @gadget:the device being declared as self-powered 674 * 675 * this affects the device status reported by the hardware driver 676 * to reflect that it now has a local power supply. 677 * 678 * returns zero on success, else negative errno. 679 */ 680static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget) 681{ 682 if (!gadget->ops->set_selfpowered) 683 return -EOPNOTSUPP; 684 return gadget->ops->set_selfpowered(gadget, 1); 685} 686 687/** 688 * usb_gadget_clear_selfpowered - clear the device selfpowered feature. 689 * @gadget:the device being declared as bus-powered 690 * 691 * this affects the device status reported by the hardware driver. 692 * some hardware may not support bus-powered operation, in which 693 * case this feature's value can never change. 694 * 695 * returns zero on success, else negative errno. 696 */ 697static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget) 698{ 699 if (!gadget->ops->set_selfpowered) 700 return -EOPNOTSUPP; 701 return gadget->ops->set_selfpowered(gadget, 0); 702} 703 704/** 705 * usb_gadget_vbus_connect - Notify controller that VBUS is powered 706 * @gadget:The device which now has VBUS power. 707 * Context: can sleep 708 * 709 * This call is used by a driver for an external transceiver (or GPIO) 710 * that detects a VBUS power session starting. Common responses include 711 * resuming the controller, activating the D+ (or D-) pullup to let the 712 * host detect that a USB device is attached, and starting to draw power 713 * (8mA or possibly more, especially after SET_CONFIGURATION). 714 * 715 * Returns zero on success, else negative errno. 716 */ 717static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget) 718{ 719 if (!gadget->ops->vbus_session) 720 return -EOPNOTSUPP; 721 return gadget->ops->vbus_session(gadget, 1); 722} 723 724/** 725 * usb_gadget_vbus_draw - constrain controller's VBUS power usage 726 * @gadget:The device whose VBUS usage is being described 727 * @mA:How much current to draw, in milliAmperes. This should be twice 728 * the value listed in the configuration descriptor bMaxPower field. 729 * 730 * This call is used by gadget drivers during SET_CONFIGURATION calls, 731 * reporting how much power the device may consume. For example, this 732 * could affect how quickly batteries are recharged. 733 * 734 * Returns zero on success, else negative errno. 735 */ 736static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA) 737{ 738 if (!gadget->ops->vbus_draw) 739 return -EOPNOTSUPP; 740 return gadget->ops->vbus_draw(gadget, mA); 741} 742 743/** 744 * usb_gadget_vbus_disconnect - notify controller about VBUS session end 745 * @gadget:the device whose VBUS supply is being described 746 * Context: can sleep 747 * 748 * This call is used by a driver for an external transceiver (or GPIO) 749 * that detects a VBUS power session ending. Common responses include 750 * reversing everything done in usb_gadget_vbus_connect(). 751 * 752 * Returns zero on success, else negative errno. 753 */ 754static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget) 755{ 756 if (!gadget->ops->vbus_session) 757 return -EOPNOTSUPP; 758 return gadget->ops->vbus_session(gadget, 0); 759} 760 761/** 762 * usb_gadget_connect - software-controlled connect to USB host 763 * @gadget:the peripheral being connected 764 * 765 * Enables the D+ (or potentially D-) pullup. The host will start 766 * enumerating this gadget when the pullup is active and a VBUS session 767 * is active (the link is powered). This pullup is always enabled unless 768 * usb_gadget_disconnect() has been used to disable it. 769 * 770 * Returns zero on success, else negative errno. 771 */ 772static inline int usb_gadget_connect(struct usb_gadget *gadget) 773{ 774 if (!gadget->ops->pullup) 775 return -EOPNOTSUPP; 776 return gadget->ops->pullup(gadget, 1); 777} 778 779/** 780 * usb_gadget_disconnect - software-controlled disconnect from USB host 781 * @gadget:the peripheral being disconnected 782 * 783 * Disables the D+ (or potentially D-) pullup, which the host may see 784 * as a disconnect (when a VBUS session is active). Not all systems 785 * support software pullup controls. 786 * 787 * This routine may be used during the gadget driver bind() call to prevent 788 * the peripheral from ever being visible to the USB host, unless later 789 * usb_gadget_connect() is called. For example, user mode components may 790 * need to be activated before the system can talk to hosts. 791 * 792 * Returns zero on success, else negative errno. 793 */ 794static inline int usb_gadget_disconnect(struct usb_gadget *gadget) 795{ 796 if (!gadget->ops->pullup) 797 return -EOPNOTSUPP; 798 return gadget->ops->pullup(gadget, 0); 799} 800 801 802/*-------------------------------------------------------------------------*/ 803 804/** 805 * struct usb_gadget_driver - driver for usb 'slave' devices 806 * @function: String describing the gadget's function 807 * @max_speed: Highest speed the driver handles. 808 * @setup: Invoked for ep0 control requests that aren't handled by 809 * the hardware level driver. Most calls must be handled by 810 * the gadget driver, including descriptor and configuration 811 * management. The 16 bit members of the setup data are in 812 * USB byte order. Called in_interrupt; this may not sleep. Driver 813 * queues a response to ep0, or returns negative to stall. 814 * @disconnect: Invoked after all transfers have been stopped, 815 * when the host is disconnected. May be called in_interrupt; this 816 * may not sleep. Some devices can't detect disconnect, so this might 817 * not be called except as part of controller shutdown. 818 * @bind: the driver's bind callback 819 * @unbind: Invoked when the driver is unbound from a gadget, 820 * usually from rmmod (after a disconnect is reported). 821 * Called in a context that permits sleeping. 822 * @suspend: Invoked on USB suspend. May be called in_interrupt. 823 * @resume: Invoked on USB resume. May be called in_interrupt. 824 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers 825 * and should be called in_interrupt. 826 * @driver: Driver model state for this driver. 827 * 828 * Devices are disabled till a gadget driver successfully bind()s, which 829 * means the driver will handle setup() requests needed to enumerate (and 830 * meet "chapter 9" requirements) then do some useful work. 831 * 832 * If gadget->is_otg is true, the gadget driver must provide an OTG 833 * descriptor during enumeration, or else fail the bind() call. In such 834 * cases, no USB traffic may flow until both bind() returns without 835 * having called usb_gadget_disconnect(), and the USB host stack has 836 * initialized. 837 * 838 * Drivers use hardware-specific knowledge to configure the usb hardware. 839 * endpoint addressing is only one of several hardware characteristics that 840 * are in descriptors the ep0 implementation returns from setup() calls. 841 * 842 * Except for ep0 implementation, most driver code shouldn't need change to 843 * run on top of different usb controllers. It'll use endpoints set up by 844 * that ep0 implementation. 845 * 846 * The usb controller driver handles a few standard usb requests. Those 847 * include set_address, and feature flags for devices, interfaces, and 848 * endpoints (the get_status, set_feature, and clear_feature requests). 849 * 850 * Accordingly, the driver's setup() callback must always implement all 851 * get_descriptor requests, returning at least a device descriptor and 852 * a configuration descriptor. Drivers must make sure the endpoint 853 * descriptors match any hardware constraints. Some hardware also constrains 854 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3). 855 * 856 * The driver's setup() callback must also implement set_configuration, 857 * and should also implement set_interface, get_configuration, and 858 * get_interface. Setting a configuration (or interface) is where 859 * endpoints should be activated or (config 0) shut down. 860 * 861 * (Note that only the default control endpoint is supported. Neither 862 * hosts nor devices generally support control traffic except to ep0.) 863 * 864 * Most devices will ignore USB suspend/resume operations, and so will 865 * not provide those callbacks. However, some may need to change modes 866 * when the host is not longer directing those activities. For example, 867 * local controls (buttons, dials, etc) may need to be re-enabled since 868 * the (remote) host can't do that any longer; or an error state might 869 * be cleared, to make the device behave identically whether or not 870 * power is maintained. 871 */ 872struct usb_gadget_driver { 873 char *function; 874 enum usb_device_speed max_speed; 875 int (*bind)(struct usb_gadget *gadget, 876 struct usb_gadget_driver *driver); 877 void (*unbind)(struct usb_gadget *); 878 int (*setup)(struct usb_gadget *, 879 const struct usb_ctrlrequest *); 880 void (*disconnect)(struct usb_gadget *); 881 void (*suspend)(struct usb_gadget *); 882 void (*resume)(struct usb_gadget *); 883 void (*reset)(struct usb_gadget *); 884 885 /* FIXME support safe rmmod */ 886 struct device_driver driver; 887}; 888 889 890 891/*-------------------------------------------------------------------------*/ 892 893/* driver modules register and unregister, as usual. 894 * these calls must be made in a context that can sleep. 895 * 896 * these will usually be implemented directly by the hardware-dependent 897 * usb bus interface driver, which will only support a single driver. 898 */ 899 900/** 901 * usb_gadget_probe_driver - probe a gadget driver 902 * @driver: the driver being registered 903 * Context: can sleep 904 * 905 * Call this in your gadget driver's module initialization function, 906 * to tell the underlying usb controller driver about your driver. 907 * The @bind() function will be called to bind it to a gadget before this 908 * registration call returns. It's expected that the @bind() function will 909 * be in init sections. 910 */ 911int usb_gadget_probe_driver(struct usb_gadget_driver *driver); 912 913/** 914 * usb_gadget_unregister_driver - unregister a gadget driver 915 * @driver:the driver being unregistered 916 * Context: can sleep 917 * 918 * Call this in your gadget driver's module cleanup function, 919 * to tell the underlying usb controller that your driver is 920 * going away. If the controller is connected to a USB host, 921 * it will first disconnect(). The driver is also requested 922 * to unbind() and clean up any device state, before this procedure 923 * finally returns. It's expected that the unbind() functions 924 * will in in exit sections, so may not be linked in some kernels. 925 */ 926int usb_gadget_unregister_driver(struct usb_gadget_driver *driver); 927 928extern int usb_add_gadget_udc_release(struct device *parent, 929 struct usb_gadget *gadget, void (*release)(struct device *dev)); 930extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget); 931extern void usb_del_gadget_udc(struct usb_gadget *gadget); 932extern int usb_udc_attach_driver(const char *name, 933 struct usb_gadget_driver *driver); 934 935/*-------------------------------------------------------------------------*/ 936 937/* utility to simplify dealing with string descriptors */ 938 939/** 940 * struct usb_string - wraps a C string and its USB id 941 * @id:the (nonzero) ID for this string 942 * @s:the string, in UTF-8 encoding 943 * 944 * If you're using usb_gadget_get_string(), use this to wrap a string 945 * together with its ID. 946 */ 947struct usb_string { 948 u8 id; 949 const char *s; 950}; 951 952/** 953 * struct usb_gadget_strings - a set of USB strings in a given language 954 * @language:identifies the strings' language (0x0409 for en-us) 955 * @strings:array of strings with their ids 956 * 957 * If you're using usb_gadget_get_string(), use this to wrap all the 958 * strings for a given language. 959 */ 960struct usb_gadget_strings { 961 u16 language; /* 0x0409 for en-us */ 962 struct usb_string *strings; 963}; 964 965struct usb_gadget_string_container { 966 struct list_head list; 967 u8 *stash[0]; 968}; 969 970/* put descriptor for string with that id into buf (buflen >= 256) */ 971int usb_gadget_get_string(struct usb_gadget_strings *table, int id, u8 *buf); 972 973/*-------------------------------------------------------------------------*/ 974 975/* utility to simplify managing config descriptors */ 976 977/* write vector of descriptors into buffer */ 978int usb_descriptor_fillbuf(void *, unsigned, 979 const struct usb_descriptor_header **); 980 981/* build config descriptor from single descriptor vector */ 982int usb_gadget_config_buf(const struct usb_config_descriptor *config, 983 void *buf, unsigned buflen, const struct usb_descriptor_header **desc); 984 985/* copy a NULL-terminated vector of descriptors */ 986struct usb_descriptor_header **usb_copy_descriptors( 987 struct usb_descriptor_header **); 988 989/** 990 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors() 991 * @v: vector of descriptors 992 */ 993static inline void usb_free_descriptors(struct usb_descriptor_header **v) 994{ 995 kfree(v); 996} 997 998struct usb_function; 999int usb_assign_descriptors(struct usb_function *f, 1000 struct usb_descriptor_header **fs, 1001 struct usb_descriptor_header **hs, 1002 struct usb_descriptor_header **ss); 1003void usb_free_all_descriptors(struct usb_function *f); 1004 1005/*-------------------------------------------------------------------------*/ 1006 1007/* utility to simplify map/unmap of usb_requests to/from DMA */ 1008 1009extern int usb_gadget_map_request(struct usb_gadget *gadget, 1010 struct usb_request *req, int is_in); 1011 1012extern void usb_gadget_unmap_request(struct usb_gadget *gadget, 1013 struct usb_request *req, int is_in); 1014 1015/*-------------------------------------------------------------------------*/ 1016 1017/* utility to set gadget state properly */ 1018 1019extern void usb_gadget_set_state(struct usb_gadget *gadget, 1020 enum usb_device_state state); 1021 1022/*-------------------------------------------------------------------------*/ 1023 1024/* utility to tell udc core that the bus reset occurs */ 1025extern void usb_gadget_udc_reset(struct usb_gadget *gadget, 1026 struct usb_gadget_driver *driver); 1027 1028/*-------------------------------------------------------------------------*/ 1029 1030/* utility to give requests back to the gadget layer */ 1031 1032extern void usb_gadget_giveback_request(struct usb_ep *ep, 1033 struct usb_request *req); 1034 1035/*-------------------------------------------------------------------------*/ 1036 1037/* utility to update vbus status for udc core, it may be scheduled */ 1038extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status); 1039 1040/*-------------------------------------------------------------------------*/ 1041 1042/* utility wrapping a simple endpoint selection policy */ 1043 1044extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *, 1045 struct usb_endpoint_descriptor *); 1046 1047 1048extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *, 1049 struct usb_endpoint_descriptor *, 1050 struct usb_ss_ep_comp_descriptor *); 1051 1052extern void usb_ep_autoconfig_reset(struct usb_gadget *); 1053 1054#endif /* __LINUX_USB_GADGET_H */ 1055