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_caps - endpoint capabilities description 145 * @type_control:Endpoint supports control type (reserved for ep0). 146 * @type_iso:Endpoint supports isochronous transfers. 147 * @type_bulk:Endpoint supports bulk transfers. 148 * @type_int:Endpoint supports interrupt transfers. 149 * @dir_in:Endpoint supports IN direction. 150 * @dir_out:Endpoint supports OUT direction. 151 */ 152struct usb_ep_caps { 153 unsigned type_control:1; 154 unsigned type_iso:1; 155 unsigned type_bulk:1; 156 unsigned type_int:1; 157 unsigned dir_in:1; 158 unsigned dir_out:1; 159}; 160 161#define USB_EP_CAPS_TYPE_CONTROL 0x01 162#define USB_EP_CAPS_TYPE_ISO 0x02 163#define USB_EP_CAPS_TYPE_BULK 0x04 164#define USB_EP_CAPS_TYPE_INT 0x08 165#define USB_EP_CAPS_TYPE_ALL \ 166 (USB_EP_CAPS_TYPE_ISO | USB_EP_CAPS_TYPE_BULK | USB_EP_CAPS_TYPE_INT) 167#define USB_EP_CAPS_DIR_IN 0x01 168#define USB_EP_CAPS_DIR_OUT 0x02 169#define USB_EP_CAPS_DIR_ALL (USB_EP_CAPS_DIR_IN | USB_EP_CAPS_DIR_OUT) 170 171#define USB_EP_CAPS(_type, _dir) \ 172 { \ 173 .type_control = !!(_type & USB_EP_CAPS_TYPE_CONTROL), \ 174 .type_iso = !!(_type & USB_EP_CAPS_TYPE_ISO), \ 175 .type_bulk = !!(_type & USB_EP_CAPS_TYPE_BULK), \ 176 .type_int = !!(_type & USB_EP_CAPS_TYPE_INT), \ 177 .dir_in = !!(_dir & USB_EP_CAPS_DIR_IN), \ 178 .dir_out = !!(_dir & USB_EP_CAPS_DIR_OUT), \ 179 } 180 181/** 182 * struct usb_ep - device side representation of USB endpoint 183 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk" 184 * @ops: Function pointers used to access hardware-specific operations. 185 * @ep_list:the gadget's ep_list holds all of its endpoints 186 * @caps:The structure describing types and directions supported by endoint. 187 * @maxpacket:The maximum packet size used on this endpoint. The initial 188 * value can sometimes be reduced (hardware allowing), according to 189 * the endpoint descriptor used to configure the endpoint. 190 * @maxpacket_limit:The maximum packet size value which can be handled by this 191 * endpoint. It's set once by UDC driver when endpoint is initialized, and 192 * should not be changed. Should not be confused with maxpacket. 193 * @max_streams: The maximum number of streams supported 194 * by this EP (0 - 16, actual number is 2^n) 195 * @mult: multiplier, 'mult' value for SS Isoc EPs 196 * @maxburst: the maximum number of bursts supported by this EP (for usb3) 197 * @driver_data:for use by the gadget driver. 198 * @address: used to identify the endpoint when finding descriptor that 199 * matches connection speed 200 * @desc: endpoint descriptor. This pointer is set before the endpoint is 201 * enabled and remains valid until the endpoint is disabled. 202 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion 203 * descriptor that is used to configure the endpoint 204 * 205 * the bus controller driver lists all the general purpose endpoints in 206 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list, 207 * and is accessed only in response to a driver setup() callback. 208 */ 209 210struct usb_ep { 211 void *driver_data; 212 213 const char *name; 214 const struct usb_ep_ops *ops; 215 struct list_head ep_list; 216 struct usb_ep_caps caps; 217 bool claimed; 218 unsigned maxpacket:16; 219 unsigned maxpacket_limit:16; 220 unsigned max_streams:16; 221 unsigned mult:2; 222 unsigned maxburst:5; 223 u8 address; 224 const struct usb_endpoint_descriptor *desc; 225 const struct usb_ss_ep_comp_descriptor *comp_desc; 226}; 227 228/*-------------------------------------------------------------------------*/ 229 230/** 231 * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint 232 * @ep:the endpoint being configured 233 * @maxpacket_limit:value of maximum packet size limit 234 * 235 * This function should be used only in UDC drivers to initialize endpoint 236 * (usually in probe function). 237 */ 238static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep, 239 unsigned maxpacket_limit) 240{ 241 ep->maxpacket_limit = maxpacket_limit; 242 ep->maxpacket = maxpacket_limit; 243} 244 245/** 246 * usb_ep_enable - configure endpoint, making it usable 247 * @ep:the endpoint being configured. may not be the endpoint named "ep0". 248 * drivers discover endpoints through the ep_list of a usb_gadget. 249 * 250 * When configurations are set, or when interface settings change, the driver 251 * will enable or disable the relevant endpoints. while it is enabled, an 252 * endpoint may be used for i/o until the driver receives a disconnect() from 253 * the host or until the endpoint is disabled. 254 * 255 * the ep0 implementation (which calls this routine) must ensure that the 256 * hardware capabilities of each endpoint match the descriptor provided 257 * for it. for example, an endpoint named "ep2in-bulk" would be usable 258 * for interrupt transfers as well as bulk, but it likely couldn't be used 259 * for iso transfers or for endpoint 14. some endpoints are fully 260 * configurable, with more generic names like "ep-a". (remember that for 261 * USB, "in" means "towards the USB master".) 262 * 263 * returns zero, or a negative error code. 264 */ 265static inline int usb_ep_enable(struct usb_ep *ep) 266{ 267 return ep->ops->enable(ep, ep->desc); 268} 269 270/** 271 * usb_ep_disable - endpoint is no longer usable 272 * @ep:the endpoint being unconfigured. may not be the endpoint named "ep0". 273 * 274 * no other task may be using this endpoint when this is called. 275 * any pending and uncompleted requests will complete with status 276 * indicating disconnect (-ESHUTDOWN) before this call returns. 277 * gadget drivers must call usb_ep_enable() again before queueing 278 * requests to the endpoint. 279 * 280 * returns zero, or a negative error code. 281 */ 282static inline int usb_ep_disable(struct usb_ep *ep) 283{ 284 return ep->ops->disable(ep); 285} 286 287/** 288 * usb_ep_alloc_request - allocate a request object to use with this endpoint 289 * @ep:the endpoint to be used with with the request 290 * @gfp_flags:GFP_* flags to use 291 * 292 * Request objects must be allocated with this call, since they normally 293 * need controller-specific setup and may even need endpoint-specific 294 * resources such as allocation of DMA descriptors. 295 * Requests may be submitted with usb_ep_queue(), and receive a single 296 * completion callback. Free requests with usb_ep_free_request(), when 297 * they are no longer needed. 298 * 299 * Returns the request, or null if one could not be allocated. 300 */ 301static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, 302 gfp_t gfp_flags) 303{ 304 return ep->ops->alloc_request(ep, gfp_flags); 305} 306 307/** 308 * usb_ep_free_request - frees a request object 309 * @ep:the endpoint associated with the request 310 * @req:the request being freed 311 * 312 * Reverses the effect of usb_ep_alloc_request(). 313 * Caller guarantees the request is not queued, and that it will 314 * no longer be requeued (or otherwise used). 315 */ 316static inline void usb_ep_free_request(struct usb_ep *ep, 317 struct usb_request *req) 318{ 319 ep->ops->free_request(ep, req); 320} 321 322/** 323 * usb_ep_queue - queues (submits) an I/O request to an endpoint. 324 * @ep:the endpoint associated with the request 325 * @req:the request being submitted 326 * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't 327 * pre-allocate all necessary memory with the request. 328 * 329 * This tells the device controller to perform the specified request through 330 * that endpoint (reading or writing a buffer). When the request completes, 331 * including being canceled by usb_ep_dequeue(), the request's completion 332 * routine is called to return the request to the driver. Any endpoint 333 * (except control endpoints like ep0) may have more than one transfer 334 * request queued; they complete in FIFO order. Once a gadget driver 335 * submits a request, that request may not be examined or modified until it 336 * is given back to that driver through the completion callback. 337 * 338 * Each request is turned into one or more packets. The controller driver 339 * never merges adjacent requests into the same packet. OUT transfers 340 * will sometimes use data that's already buffered in the hardware. 341 * Drivers can rely on the fact that the first byte of the request's buffer 342 * always corresponds to the first byte of some USB packet, for both 343 * IN and OUT transfers. 344 * 345 * Bulk endpoints can queue any amount of data; the transfer is packetized 346 * automatically. The last packet will be short if the request doesn't fill it 347 * out completely. Zero length packets (ZLPs) should be avoided in portable 348 * protocols since not all usb hardware can successfully handle zero length 349 * packets. (ZLPs may be explicitly written, and may be implicitly written if 350 * the request 'zero' flag is set.) Bulk endpoints may also be used 351 * for interrupt transfers; but the reverse is not true, and some endpoints 352 * won't support every interrupt transfer. (Such as 768 byte packets.) 353 * 354 * Interrupt-only endpoints are less functional than bulk endpoints, for 355 * example by not supporting queueing or not handling buffers that are 356 * larger than the endpoint's maxpacket size. They may also treat data 357 * toggle differently. 358 * 359 * Control endpoints ... after getting a setup() callback, the driver queues 360 * one response (even if it would be zero length). That enables the 361 * status ack, after transferring data as specified in the response. Setup 362 * functions may return negative error codes to generate protocol stalls. 363 * (Note that some USB device controllers disallow protocol stall responses 364 * in some cases.) When control responses are deferred (the response is 365 * written after the setup callback returns), then usb_ep_set_halt() may be 366 * used on ep0 to trigger protocol stalls. Depending on the controller, 367 * it may not be possible to trigger a status-stage protocol stall when the 368 * data stage is over, that is, from within the response's completion 369 * routine. 370 * 371 * For periodic endpoints, like interrupt or isochronous ones, the usb host 372 * arranges to poll once per interval, and the gadget driver usually will 373 * have queued some data to transfer at that time. 374 * 375 * Returns zero, or a negative error code. Endpoints that are not enabled 376 * report errors; errors will also be 377 * reported when the usb peripheral is disconnected. 378 */ 379static inline int usb_ep_queue(struct usb_ep *ep, 380 struct usb_request *req, gfp_t gfp_flags) 381{ 382 return ep->ops->queue(ep, req, gfp_flags); 383} 384 385/** 386 * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint 387 * @ep:the endpoint associated with the request 388 * @req:the request being canceled 389 * 390 * If the request is still active on the endpoint, it is dequeued and its 391 * completion routine is called (with status -ECONNRESET); else a negative 392 * error code is returned. This is guaranteed to happen before the call to 393 * usb_ep_dequeue() returns. 394 * 395 * Note that some hardware can't clear out write fifos (to unlink the request 396 * at the head of the queue) except as part of disconnecting from usb. Such 397 * restrictions prevent drivers from supporting configuration changes, 398 * even to configuration zero (a "chapter 9" requirement). 399 */ 400static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req) 401{ 402 return ep->ops->dequeue(ep, req); 403} 404 405/** 406 * usb_ep_set_halt - sets the endpoint halt feature. 407 * @ep: the non-isochronous endpoint being stalled 408 * 409 * Use this to stall an endpoint, perhaps as an error report. 410 * Except for control endpoints, 411 * the endpoint stays halted (will not stream any data) until the host 412 * clears this feature; drivers may need to empty the endpoint's request 413 * queue first, to make sure no inappropriate transfers happen. 414 * 415 * Note that while an endpoint CLEAR_FEATURE will be invisible to the 416 * gadget driver, a SET_INTERFACE will not be. To reset endpoints for the 417 * current altsetting, see usb_ep_clear_halt(). When switching altsettings, 418 * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints. 419 * 420 * Returns zero, or a negative error code. On success, this call sets 421 * underlying hardware state that blocks data transfers. 422 * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any 423 * transfer requests are still queued, or if the controller hardware 424 * (usually a FIFO) still holds bytes that the host hasn't collected. 425 */ 426static inline int usb_ep_set_halt(struct usb_ep *ep) 427{ 428 return ep->ops->set_halt(ep, 1); 429} 430 431/** 432 * usb_ep_clear_halt - clears endpoint halt, and resets toggle 433 * @ep:the bulk or interrupt endpoint being reset 434 * 435 * Use this when responding to the standard usb "set interface" request, 436 * for endpoints that aren't reconfigured, after clearing any other state 437 * in the endpoint's i/o queue. 438 * 439 * Returns zero, or a negative error code. On success, this call clears 440 * the underlying hardware state reflecting endpoint halt and data toggle. 441 * Note that some hardware can't support this request (like pxa2xx_udc), 442 * and accordingly can't correctly implement interface altsettings. 443 */ 444static inline int usb_ep_clear_halt(struct usb_ep *ep) 445{ 446 return ep->ops->set_halt(ep, 0); 447} 448 449/** 450 * usb_ep_set_wedge - sets the halt feature and ignores clear requests 451 * @ep: the endpoint being wedged 452 * 453 * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT) 454 * requests. If the gadget driver clears the halt status, it will 455 * automatically unwedge the endpoint. 456 * 457 * Returns zero on success, else negative errno. 458 */ 459static inline int 460usb_ep_set_wedge(struct usb_ep *ep) 461{ 462 if (ep->ops->set_wedge) 463 return ep->ops->set_wedge(ep); 464 else 465 return ep->ops->set_halt(ep, 1); 466} 467 468/** 469 * usb_ep_fifo_status - returns number of bytes in fifo, or error 470 * @ep: the endpoint whose fifo status is being checked. 471 * 472 * FIFO endpoints may have "unclaimed data" in them in certain cases, 473 * such as after aborted transfers. Hosts may not have collected all 474 * the IN data written by the gadget driver (and reported by a request 475 * completion). The gadget driver may not have collected all the data 476 * written OUT to it by the host. Drivers that need precise handling for 477 * fault reporting or recovery may need to use this call. 478 * 479 * This returns the number of such bytes in the fifo, or a negative 480 * errno if the endpoint doesn't use a FIFO or doesn't support such 481 * precise handling. 482 */ 483static inline int usb_ep_fifo_status(struct usb_ep *ep) 484{ 485 if (ep->ops->fifo_status) 486 return ep->ops->fifo_status(ep); 487 else 488 return -EOPNOTSUPP; 489} 490 491/** 492 * usb_ep_fifo_flush - flushes contents of a fifo 493 * @ep: the endpoint whose fifo is being flushed. 494 * 495 * This call may be used to flush the "unclaimed data" that may exist in 496 * an endpoint fifo after abnormal transaction terminations. The call 497 * must never be used except when endpoint is not being used for any 498 * protocol translation. 499 */ 500static inline void usb_ep_fifo_flush(struct usb_ep *ep) 501{ 502 if (ep->ops->fifo_flush) 503 ep->ops->fifo_flush(ep); 504} 505 506 507/*-------------------------------------------------------------------------*/ 508 509struct usb_dcd_config_params { 510 __u8 bU1devExitLat; /* U1 Device exit Latency */ 511#define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */ 512 __le16 bU2DevExitLat; /* U2 Device exit Latency */ 513#define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */ 514}; 515 516 517struct usb_gadget; 518struct usb_gadget_driver; 519struct usb_udc; 520 521/* the rest of the api to the controller hardware: device operations, 522 * which don't involve endpoints (or i/o). 523 */ 524struct usb_gadget_ops { 525 int (*get_frame)(struct usb_gadget *); 526 int (*wakeup)(struct usb_gadget *); 527 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered); 528 int (*vbus_session) (struct usb_gadget *, int is_active); 529 int (*vbus_draw) (struct usb_gadget *, unsigned mA); 530 int (*pullup) (struct usb_gadget *, int is_on); 531 int (*ioctl)(struct usb_gadget *, 532 unsigned code, unsigned long param); 533 void (*get_config_params)(struct usb_dcd_config_params *); 534 int (*udc_start)(struct usb_gadget *, 535 struct usb_gadget_driver *); 536 int (*udc_stop)(struct usb_gadget *); 537 struct usb_ep *(*match_ep)(struct usb_gadget *, 538 struct usb_endpoint_descriptor *, 539 struct usb_ss_ep_comp_descriptor *); 540}; 541 542/** 543 * struct usb_gadget - represents a usb slave device 544 * @work: (internal use) Workqueue to be used for sysfs_notify() 545 * @udc: struct usb_udc pointer for this gadget 546 * @ops: Function pointers used to access hardware-specific operations. 547 * @ep0: Endpoint zero, used when reading or writing responses to 548 * driver setup() requests 549 * @ep_list: List of other endpoints supported by the device. 550 * @speed: Speed of current connection to USB host. 551 * @max_speed: Maximal speed the UDC can handle. UDC must support this 552 * and all slower speeds. 553 * @state: the state we are now (attached, suspended, configured, etc) 554 * @name: Identifies the controller hardware type. Used in diagnostics 555 * and sometimes configuration. 556 * @dev: Driver model state for this abstract device. 557 * @out_epnum: last used out ep number 558 * @in_epnum: last used in ep number 559 * @otg_caps: OTG capabilities of this gadget. 560 * @sg_supported: true if we can handle scatter-gather 561 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the 562 * gadget driver must provide a USB OTG descriptor. 563 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable 564 * is in the Mini-AB jack, and HNP has been used to switch roles 565 * so that the "A" device currently acts as A-Peripheral, not A-Host. 566 * @a_hnp_support: OTG device feature flag, indicating that the A-Host 567 * supports HNP at this port. 568 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host 569 * only supports HNP on a different root port. 570 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host 571 * enabled HNP support. 572 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to 573 * MaxPacketSize. 574 * @is_selfpowered: if the gadget is self-powered. 575 * @deactivated: True if gadget is deactivated - in deactivated state it cannot 576 * be connected. 577 * @connected: True if gadget is connected. 578 * 579 * Gadgets have a mostly-portable "gadget driver" implementing device 580 * functions, handling all usb configurations and interfaces. Gadget 581 * drivers talk to hardware-specific code indirectly, through ops vectors. 582 * That insulates the gadget driver from hardware details, and packages 583 * the hardware endpoints through generic i/o queues. The "usb_gadget" 584 * and "usb_ep" interfaces provide that insulation from the hardware. 585 * 586 * Except for the driver data, all fields in this structure are 587 * read-only to the gadget driver. That driver data is part of the 588 * "driver model" infrastructure in 2.6 (and later) kernels, and for 589 * earlier systems is grouped in a similar structure that's not known 590 * to the rest of the kernel. 591 * 592 * Values of the three OTG device feature flags are updated before the 593 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before 594 * driver suspend() calls. They are valid only when is_otg, and when the 595 * device is acting as a B-Peripheral (so is_a_peripheral is false). 596 */ 597struct usb_gadget { 598 struct work_struct work; 599 struct usb_udc *udc; 600 /* readonly to gadget driver */ 601 const struct usb_gadget_ops *ops; 602 struct usb_ep *ep0; 603 struct list_head ep_list; /* of usb_ep */ 604 enum usb_device_speed speed; 605 enum usb_device_speed max_speed; 606 enum usb_device_state state; 607 const char *name; 608 struct device dev; 609 unsigned out_epnum; 610 unsigned in_epnum; 611 struct usb_otg_caps *otg_caps; 612 613 unsigned sg_supported:1; 614 unsigned is_otg:1; 615 unsigned is_a_peripheral:1; 616 unsigned b_hnp_enable:1; 617 unsigned a_hnp_support:1; 618 unsigned a_alt_hnp_support:1; 619 unsigned quirk_ep_out_aligned_size:1; 620 unsigned quirk_altset_not_supp:1; 621 unsigned quirk_stall_not_supp:1; 622 unsigned quirk_zlp_not_supp:1; 623 unsigned is_selfpowered:1; 624 unsigned deactivated:1; 625 unsigned connected:1; 626}; 627#define work_to_gadget(w) (container_of((w), struct usb_gadget, work)) 628 629static inline void set_gadget_data(struct usb_gadget *gadget, void *data) 630 { dev_set_drvdata(&gadget->dev, data); } 631static inline void *get_gadget_data(struct usb_gadget *gadget) 632 { return dev_get_drvdata(&gadget->dev); } 633static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev) 634{ 635 return container_of(dev, struct usb_gadget, dev); 636} 637 638/* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */ 639#define gadget_for_each_ep(tmp, gadget) \ 640 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list) 641 642/** 643 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget 644 * requires quirk_ep_out_aligned_size, otherwise reguens len. 645 * @g: controller to check for quirk 646 * @ep: the endpoint whose maxpacketsize is used to align @len 647 * @len: buffer size's length to align to @ep's maxpacketsize 648 * 649 * This helper is used in case it's required for any reason to check and maybe 650 * align buffer's size to an ep's maxpacketsize. 651 */ 652static inline size_t 653usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len) 654{ 655 return !g->quirk_ep_out_aligned_size ? len : 656 round_up(len, (size_t)ep->desc->wMaxPacketSize); 657} 658 659/** 660 * gadget_is_altset_supported - return true iff the hardware supports 661 * altsettings 662 * @g: controller to check for quirk 663 */ 664static inline int gadget_is_altset_supported(struct usb_gadget *g) 665{ 666 return !g->quirk_altset_not_supp; 667} 668 669/** 670 * gadget_is_stall_supported - return true iff the hardware supports stalling 671 * @g: controller to check for quirk 672 */ 673static inline int gadget_is_stall_supported(struct usb_gadget *g) 674{ 675 return !g->quirk_stall_not_supp; 676} 677 678/** 679 * gadget_is_zlp_supported - return true iff the hardware supports zlp 680 * @g: controller to check for quirk 681 */ 682static inline int gadget_is_zlp_supported(struct usb_gadget *g) 683{ 684 return !g->quirk_zlp_not_supp; 685} 686 687/** 688 * gadget_is_dualspeed - return true iff the hardware handles high speed 689 * @g: controller that might support both high and full speeds 690 */ 691static inline int gadget_is_dualspeed(struct usb_gadget *g) 692{ 693 return g->max_speed >= USB_SPEED_HIGH; 694} 695 696/** 697 * gadget_is_superspeed() - return true if the hardware handles superspeed 698 * @g: controller that might support superspeed 699 */ 700static inline int gadget_is_superspeed(struct usb_gadget *g) 701{ 702 return g->max_speed >= USB_SPEED_SUPER; 703} 704 705/** 706 * gadget_is_otg - return true iff the hardware is OTG-ready 707 * @g: controller that might have a Mini-AB connector 708 * 709 * This is a runtime test, since kernels with a USB-OTG stack sometimes 710 * run on boards which only have a Mini-B (or Mini-A) connector. 711 */ 712static inline int gadget_is_otg(struct usb_gadget *g) 713{ 714#ifdef CONFIG_USB_OTG 715 return g->is_otg; 716#else 717 return 0; 718#endif 719} 720 721/** 722 * usb_gadget_frame_number - returns the current frame number 723 * @gadget: controller that reports the frame number 724 * 725 * Returns the usb frame number, normally eleven bits from a SOF packet, 726 * or negative errno if this device doesn't support this capability. 727 */ 728static inline int usb_gadget_frame_number(struct usb_gadget *gadget) 729{ 730 return gadget->ops->get_frame(gadget); 731} 732 733/** 734 * usb_gadget_wakeup - tries to wake up the host connected to this gadget 735 * @gadget: controller used to wake up the host 736 * 737 * Returns zero on success, else negative error code if the hardware 738 * doesn't support such attempts, or its support has not been enabled 739 * by the usb host. Drivers must return device descriptors that report 740 * their ability to support this, or hosts won't enable it. 741 * 742 * This may also try to use SRP to wake the host and start enumeration, 743 * even if OTG isn't otherwise in use. OTG devices may also start 744 * remote wakeup even when hosts don't explicitly enable it. 745 */ 746static inline int usb_gadget_wakeup(struct usb_gadget *gadget) 747{ 748 if (!gadget->ops->wakeup) 749 return -EOPNOTSUPP; 750 return gadget->ops->wakeup(gadget); 751} 752 753/** 754 * usb_gadget_set_selfpowered - sets the device selfpowered feature. 755 * @gadget:the device being declared as self-powered 756 * 757 * this affects the device status reported by the hardware driver 758 * to reflect that it now has a local power supply. 759 * 760 * returns zero on success, else negative errno. 761 */ 762static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget) 763{ 764 if (!gadget->ops->set_selfpowered) 765 return -EOPNOTSUPP; 766 return gadget->ops->set_selfpowered(gadget, 1); 767} 768 769/** 770 * usb_gadget_clear_selfpowered - clear the device selfpowered feature. 771 * @gadget:the device being declared as bus-powered 772 * 773 * this affects the device status reported by the hardware driver. 774 * some hardware may not support bus-powered operation, in which 775 * case this feature's value can never change. 776 * 777 * returns zero on success, else negative errno. 778 */ 779static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget) 780{ 781 if (!gadget->ops->set_selfpowered) 782 return -EOPNOTSUPP; 783 return gadget->ops->set_selfpowered(gadget, 0); 784} 785 786/** 787 * usb_gadget_vbus_connect - Notify controller that VBUS is powered 788 * @gadget:The device which now has VBUS power. 789 * Context: can sleep 790 * 791 * This call is used by a driver for an external transceiver (or GPIO) 792 * that detects a VBUS power session starting. Common responses include 793 * resuming the controller, activating the D+ (or D-) pullup to let the 794 * host detect that a USB device is attached, and starting to draw power 795 * (8mA or possibly more, especially after SET_CONFIGURATION). 796 * 797 * Returns zero on success, else negative errno. 798 */ 799static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget) 800{ 801 if (!gadget->ops->vbus_session) 802 return -EOPNOTSUPP; 803 return gadget->ops->vbus_session(gadget, 1); 804} 805 806/** 807 * usb_gadget_vbus_draw - constrain controller's VBUS power usage 808 * @gadget:The device whose VBUS usage is being described 809 * @mA:How much current to draw, in milliAmperes. This should be twice 810 * the value listed in the configuration descriptor bMaxPower field. 811 * 812 * This call is used by gadget drivers during SET_CONFIGURATION calls, 813 * reporting how much power the device may consume. For example, this 814 * could affect how quickly batteries are recharged. 815 * 816 * Returns zero on success, else negative errno. 817 */ 818static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA) 819{ 820 if (!gadget->ops->vbus_draw) 821 return -EOPNOTSUPP; 822 return gadget->ops->vbus_draw(gadget, mA); 823} 824 825/** 826 * usb_gadget_vbus_disconnect - notify controller about VBUS session end 827 * @gadget:the device whose VBUS supply is being described 828 * Context: can sleep 829 * 830 * This call is used by a driver for an external transceiver (or GPIO) 831 * that detects a VBUS power session ending. Common responses include 832 * reversing everything done in usb_gadget_vbus_connect(). 833 * 834 * Returns zero on success, else negative errno. 835 */ 836static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget) 837{ 838 if (!gadget->ops->vbus_session) 839 return -EOPNOTSUPP; 840 return gadget->ops->vbus_session(gadget, 0); 841} 842 843/** 844 * usb_gadget_connect - software-controlled connect to USB host 845 * @gadget:the peripheral being connected 846 * 847 * Enables the D+ (or potentially D-) pullup. The host will start 848 * enumerating this gadget when the pullup is active and a VBUS session 849 * is active (the link is powered). This pullup is always enabled unless 850 * usb_gadget_disconnect() has been used to disable it. 851 * 852 * Returns zero on success, else negative errno. 853 */ 854static inline int usb_gadget_connect(struct usb_gadget *gadget) 855{ 856 int ret; 857 858 if (!gadget->ops->pullup) 859 return -EOPNOTSUPP; 860 861 if (gadget->deactivated) { 862 /* 863 * If gadget is deactivated we only save new state. 864 * Gadget will be connected automatically after activation. 865 */ 866 gadget->connected = true; 867 return 0; 868 } 869 870 ret = gadget->ops->pullup(gadget, 1); 871 if (!ret) 872 gadget->connected = 1; 873 return ret; 874} 875 876/** 877 * usb_gadget_disconnect - software-controlled disconnect from USB host 878 * @gadget:the peripheral being disconnected 879 * 880 * Disables the D+ (or potentially D-) pullup, which the host may see 881 * as a disconnect (when a VBUS session is active). Not all systems 882 * support software pullup controls. 883 * 884 * Returns zero on success, else negative errno. 885 */ 886static inline int usb_gadget_disconnect(struct usb_gadget *gadget) 887{ 888 int ret; 889 890 if (!gadget->ops->pullup) 891 return -EOPNOTSUPP; 892 893 if (gadget->deactivated) { 894 /* 895 * If gadget is deactivated we only save new state. 896 * Gadget will stay disconnected after activation. 897 */ 898 gadget->connected = false; 899 return 0; 900 } 901 902 ret = gadget->ops->pullup(gadget, 0); 903 if (!ret) 904 gadget->connected = 0; 905 return ret; 906} 907 908/** 909 * usb_gadget_deactivate - deactivate function which is not ready to work 910 * @gadget: the peripheral being deactivated 911 * 912 * This routine may be used during the gadget driver bind() call to prevent 913 * the peripheral from ever being visible to the USB host, unless later 914 * usb_gadget_activate() is called. For example, user mode components may 915 * need to be activated before the system can talk to hosts. 916 * 917 * Returns zero on success, else negative errno. 918 */ 919static inline int usb_gadget_deactivate(struct usb_gadget *gadget) 920{ 921 int ret; 922 923 if (gadget->deactivated) 924 return 0; 925 926 if (gadget->connected) { 927 ret = usb_gadget_disconnect(gadget); 928 if (ret) 929 return ret; 930 /* 931 * If gadget was being connected before deactivation, we want 932 * to reconnect it in usb_gadget_activate(). 933 */ 934 gadget->connected = true; 935 } 936 gadget->deactivated = true; 937 938 return 0; 939} 940 941/** 942 * usb_gadget_activate - activate function which is not ready to work 943 * @gadget: the peripheral being activated 944 * 945 * This routine activates gadget which was previously deactivated with 946 * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed. 947 * 948 * Returns zero on success, else negative errno. 949 */ 950static inline int usb_gadget_activate(struct usb_gadget *gadget) 951{ 952 if (!gadget->deactivated) 953 return 0; 954 955 gadget->deactivated = false; 956 957 /* 958 * If gadget has been connected before deactivation, or became connected 959 * while it was being deactivated, we call usb_gadget_connect(). 960 */ 961 if (gadget->connected) 962 return usb_gadget_connect(gadget); 963 964 return 0; 965} 966 967/*-------------------------------------------------------------------------*/ 968 969/** 970 * struct usb_gadget_driver - driver for usb 'slave' devices 971 * @function: String describing the gadget's function 972 * @max_speed: Highest speed the driver handles. 973 * @setup: Invoked for ep0 control requests that aren't handled by 974 * the hardware level driver. Most calls must be handled by 975 * the gadget driver, including descriptor and configuration 976 * management. The 16 bit members of the setup data are in 977 * USB byte order. Called in_interrupt; this may not sleep. Driver 978 * queues a response to ep0, or returns negative to stall. 979 * @disconnect: Invoked after all transfers have been stopped, 980 * when the host is disconnected. May be called in_interrupt; this 981 * may not sleep. Some devices can't detect disconnect, so this might 982 * not be called except as part of controller shutdown. 983 * @bind: the driver's bind callback 984 * @unbind: Invoked when the driver is unbound from a gadget, 985 * usually from rmmod (after a disconnect is reported). 986 * Called in a context that permits sleeping. 987 * @suspend: Invoked on USB suspend. May be called in_interrupt. 988 * @resume: Invoked on USB resume. May be called in_interrupt. 989 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers 990 * and should be called in_interrupt. 991 * @driver: Driver model state for this driver. 992 * 993 * Devices are disabled till a gadget driver successfully bind()s, which 994 * means the driver will handle setup() requests needed to enumerate (and 995 * meet "chapter 9" requirements) then do some useful work. 996 * 997 * If gadget->is_otg is true, the gadget driver must provide an OTG 998 * descriptor during enumeration, or else fail the bind() call. In such 999 * cases, no USB traffic may flow until both bind() returns without 1000 * having called usb_gadget_disconnect(), and the USB host stack has
1001 * initialized. 1002 * 1003 * Drivers use hardware-specific knowledge to configure the usb hardware. 1004 * endpoint addressing is only one of several hardware characteristics that 1005 * are in descriptors the ep0 implementation returns from setup() calls. 1006 * 1007 * Except for ep0 implementation, most driver code shouldn't need change to 1008 * run on top of different usb controllers. It'll use endpoints set up by 1009 * that ep0 implementation. 1010 * 1011 * The usb controller driver handles a few standard usb requests. Those 1012 * include set_address, and feature flags for devices, interfaces, and 1013 * endpoints (the get_status, set_feature, and clear_feature requests). 1014 * 1015 * Accordingly, the driver's setup() callback must always implement all 1016 * get_descriptor requests, returning at least a device descriptor and 1017 * a configuration descriptor. Drivers must make sure the endpoint 1018 * descriptors match any hardware constraints. Some hardware also constrains 1019 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3). 1020 * 1021 * The driver's setup() callback must also implement set_configuration, 1022 * and should also implement set_interface, get_configuration, and 1023 * get_interface. Setting a configuration (or interface) is where 1024 * endpoints should be activated or (config 0) shut down. 1025 * 1026 * (Note that only the default control endpoint is supported. Neither 1027 * hosts nor devices generally support control traffic except to ep0.) 1028 * 1029 * Most devices will ignore USB suspend/resume operations, and so will 1030 * not provide those callbacks. However, some may need to change modes 1031 * when the host is not longer directing those activities. For example, 1032 * local controls (buttons, dials, etc) may need to be re-enabled since 1033 * the (remote) host can't do that any longer; or an error state might 1034 * be cleared, to make the device behave identically whether or not 1035 * power is maintained. 1036 */ 1037struct usb_gadget_driver { 1038 char *function; 1039 enum usb_device_speed max_speed; 1040 int (*bind)(struct usb_gadget *gadget, 1041 struct usb_gadget_driver *driver); 1042 void (*unbind)(struct usb_gadget *); 1043 int (*setup)(struct usb_gadget *, 1044 const struct usb_ctrlrequest *); 1045 void (*disconnect)(struct usb_gadget *); 1046 void (*suspend)(struct usb_gadget *); 1047 void (*resume)(struct usb_gadget *); 1048 void (*reset)(struct usb_gadget *); 1049 1050 /* FIXME support safe rmmod */ 1051 struct device_driver driver; 1052}; 1053 1054 1055 1056/*-------------------------------------------------------------------------*/ 1057 1058/* driver modules register and unregister, as usual. 1059 * these calls must be made in a context that can sleep. 1060 * 1061 * these will usually be implemented directly by the hardware-dependent 1062 * usb bus interface driver, which will only support a single driver. 1063 */ 1064 1065/** 1066 * usb_gadget_probe_driver - probe a gadget driver 1067 * @driver: the driver being registered 1068 * Context: can sleep 1069 * 1070 * Call this in your gadget driver's module initialization function, 1071 * to tell the underlying usb controller driver about your driver. 1072 * The @bind() function will be called to bind it to a gadget before this 1073 * registration call returns. It's expected that the @bind() function will 1074 * be in init sections. 1075 */ 1076int usb_gadget_probe_driver(struct usb_gadget_driver *driver); 1077 1078/** 1079 * usb_gadget_unregister_driver - unregister a gadget driver 1080 * @driver:the driver being unregistered 1081 * Context: can sleep 1082 * 1083 * Call this in your gadget driver's module cleanup function, 1084 * to tell the underlying usb controller that your driver is 1085 * going away. If the controller is connected to a USB host, 1086 * it will first disconnect(). The driver is also requested 1087 * to unbind() and clean up any device state, before this procedure 1088 * finally returns. It's expected that the unbind() functions 1089 * will in in exit sections, so may not be linked in some kernels. 1090 */ 1091int usb_gadget_unregister_driver(struct usb_gadget_driver *driver); 1092 1093extern int usb_add_gadget_udc_release(struct device *parent, 1094 struct usb_gadget *gadget, void (*release)(struct device *dev)); 1095extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget); 1096extern void usb_del_gadget_udc(struct usb_gadget *gadget); 1097extern int usb_udc_attach_driver(const char *name, 1098 struct usb_gadget_driver *driver); 1099 1100/*-------------------------------------------------------------------------*/ 1101 1102/* utility to simplify dealing with string descriptors */ 1103 1104/** 1105 * struct usb_string - wraps a C string and its USB id 1106 * @id:the (nonzero) ID for this string 1107 * @s:the string, in UTF-8 encoding 1108 * 1109 * If you're using usb_gadget_get_string(), use this to wrap a string 1110 * together with its ID. 1111 */ 1112struct usb_string { 1113 u8 id; 1114 const char *s; 1115}; 1116 1117/** 1118 * struct usb_gadget_strings - a set of USB strings in a given language 1119 * @language:identifies the strings' language (0x0409 for en-us) 1120 * @strings:array of strings with their ids 1121 * 1122 * If you're using usb_gadget_get_string(), use this to wrap all the 1123 * strings for a given language. 1124 */ 1125struct usb_gadget_strings { 1126 u16 language; /* 0x0409 for en-us */ 1127 struct usb_string *strings; 1128}; 1129 1130struct usb_gadget_string_container { 1131 struct list_head list; 1132 u8 *stash[0]; 1133}; 1134 1135/* put descriptor for string with that id into buf (buflen >= 256) */ 1136int usb_gadget_get_string(struct usb_gadget_strings *table, int id, u8 *buf); 1137 1138/*-------------------------------------------------------------------------*/ 1139 1140/* utility to simplify managing config descriptors */ 1141 1142/* write vector of descriptors into buffer */ 1143int usb_descriptor_fillbuf(void *, unsigned, 1144 const struct usb_descriptor_header **); 1145 1146/* build config descriptor from single descriptor vector */ 1147int usb_gadget_config_buf(const struct usb_config_descriptor *config, 1148 void *buf, unsigned buflen, const struct usb_descriptor_header **desc); 1149 1150/* copy a NULL-terminated vector of descriptors */ 1151struct usb_descriptor_header **usb_copy_descriptors( 1152 struct usb_descriptor_header **); 1153 1154/** 1155 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors() 1156 * @v: vector of descriptors 1157 */ 1158static inline void usb_free_descriptors(struct usb_descriptor_header **v) 1159{ 1160 kfree(v); 1161} 1162 1163struct usb_function; 1164int usb_assign_descriptors(struct usb_function *f, 1165 struct usb_descriptor_header **fs, 1166 struct usb_descriptor_header **hs, 1167 struct usb_descriptor_header **ss); 1168void usb_free_all_descriptors(struct usb_function *f); 1169 1170struct usb_descriptor_header *usb_otg_descriptor_alloc( 1171 struct usb_gadget *gadget); 1172int usb_otg_descriptor_init(struct usb_gadget *gadget, 1173 struct usb_descriptor_header *otg_desc); 1174/*-------------------------------------------------------------------------*/ 1175 1176/* utility to simplify map/unmap of usb_requests to/from DMA */ 1177 1178extern int usb_gadget_map_request(struct usb_gadget *gadget, 1179 struct usb_request *req, int is_in); 1180 1181extern void usb_gadget_unmap_request(struct usb_gadget *gadget, 1182 struct usb_request *req, int is_in); 1183 1184/*-------------------------------------------------------------------------*/ 1185 1186/* utility to set gadget state properly */ 1187 1188extern void usb_gadget_set_state(struct usb_gadget *gadget, 1189 enum usb_device_state state); 1190 1191/*-------------------------------------------------------------------------*/ 1192 1193/* utility to tell udc core that the bus reset occurs */ 1194extern void usb_gadget_udc_reset(struct usb_gadget *gadget, 1195 struct usb_gadget_driver *driver); 1196 1197/*-------------------------------------------------------------------------*/ 1198 1199/* utility to give requests back to the gadget layer */ 1200 1201extern void usb_gadget_giveback_request(struct usb_ep *ep, 1202 struct usb_request *req); 1203 1204/*-------------------------------------------------------------------------*/ 1205 1206/* utility to find endpoint by name */ 1207 1208extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g, 1209 const char *name); 1210 1211/*-------------------------------------------------------------------------*/ 1212 1213/* utility to check if endpoint caps match descriptor needs */ 1214 1215extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget, 1216 struct usb_ep *ep, struct usb_endpoint_descriptor *desc, 1217 struct usb_ss_ep_comp_descriptor *ep_comp); 1218 1219/*-------------------------------------------------------------------------*/ 1220 1221/* utility to update vbus status for udc core, it may be scheduled */ 1222extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status); 1223 1224/*-------------------------------------------------------------------------*/ 1225 1226/* utility wrapping a simple endpoint selection policy */ 1227 1228extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *, 1229 struct usb_endpoint_descriptor *); 1230 1231 1232extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *, 1233 struct usb_endpoint_descriptor *, 1234 struct usb_ss_ep_comp_descriptor *); 1235 1236extern void usb_ep_autoconfig_reset(struct usb_gadget *); 1237 1238#endif /* __LINUX_USB_GADGET_H */ 1239