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 28 struct 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 91 struct 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 */ 123 struct 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 */ 170 struct 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 shoud be used only in UDC drivers to initialize endpoint 194 * (usually in probe function). 195 */ 196 static 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 */ 223 static 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 */ 240 static 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 */ 259 static 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 */ 274 static 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 */ 337 static 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 */ 358 static 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 */ 384 static 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 */ 402 static 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 */ 417 static inline int 418 usb_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 */ 441 static 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 */ 458 static 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 /*-------------------------------------------------------------------------*/ 466 467 struct 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 }; 473 474 475 struct usb_gadget; 476 struct usb_gadget_driver; 477 478 /* the rest of the api to the controller hardware: device operations, 479 * which don't involve endpoints (or i/o). 480 */ 481 struct usb_gadget_ops { 482 int (*get_frame)(struct usb_gadget *); 483 int (*wakeup)(struct usb_gadget *); 484 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered); 485 int (*vbus_session) (struct usb_gadget *, int is_active); 486 int (*vbus_draw) (struct usb_gadget *, unsigned mA); 487 int (*pullup) (struct usb_gadget *, int is_on); 488 int (*ioctl)(struct usb_gadget *, 489 unsigned code, unsigned long param); 490 void (*get_config_params)(struct usb_dcd_config_params *); 491 int (*udc_start)(struct usb_gadget *, 492 struct usb_gadget_driver *); 493 int (*udc_stop)(struct usb_gadget *); 494 }; 495 496 /** 497 * struct usb_gadget - represents a usb slave device 498 * @work: (internal use) Workqueue to be used for sysfs_notify() 499 * @ops: Function pointers used to access hardware-specific operations. 500 * @ep0: Endpoint zero, used when reading or writing responses to 501 * driver setup() requests 502 * @ep_list: List of other endpoints supported by the device. 503 * @speed: Speed of current connection to USB host. 504 * @max_speed: Maximal speed the UDC can handle. UDC must support this 505 * and all slower speeds. 506 * @state: the state we are now (attached, suspended, configured, etc) 507 * @name: Identifies the controller hardware type. Used in diagnostics 508 * and sometimes configuration. 509 * @dev: Driver model state for this abstract device. 510 * @out_epnum: last used out ep number 511 * @in_epnum: last used in ep number 512 * @sg_supported: true if we can handle scatter-gather 513 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the 514 * gadget driver must provide a USB OTG descriptor. 515 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable 516 * is in the Mini-AB jack, and HNP has been used to switch roles 517 * so that the "A" device currently acts as A-Peripheral, not A-Host. 518 * @a_hnp_support: OTG device feature flag, indicating that the A-Host 519 * supports HNP at this port. 520 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host 521 * only supports HNP on a different root port. 522 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host 523 * enabled HNP support. 524 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to 525 * MaxPacketSize. 526 * @is_selfpowered: if the gadget is self-powered. 527 * 528 * Gadgets have a mostly-portable "gadget driver" implementing device 529 * functions, handling all usb configurations and interfaces. Gadget 530 * drivers talk to hardware-specific code indirectly, through ops vectors. 531 * That insulates the gadget driver from hardware details, and packages 532 * the hardware endpoints through generic i/o queues. The "usb_gadget" 533 * and "usb_ep" interfaces provide that insulation from the hardware. 534 * 535 * Except for the driver data, all fields in this structure are 536 * read-only to the gadget driver. That driver data is part of the 537 * "driver model" infrastructure in 2.6 (and later) kernels, and for 538 * earlier systems is grouped in a similar structure that's not known 539 * to the rest of the kernel. 540 * 541 * Values of the three OTG device feature flags are updated before the 542 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before 543 * driver suspend() calls. They are valid only when is_otg, and when the 544 * device is acting as a B-Peripheral (so is_a_peripheral is false). 545 */ 546 struct usb_gadget { 547 struct work_struct work; 548 /* readonly to gadget driver */ 549 const struct usb_gadget_ops *ops; 550 struct usb_ep *ep0; 551 struct list_head ep_list; /* of usb_ep */ 552 enum usb_device_speed speed; 553 enum usb_device_speed max_speed; 554 enum usb_device_state state; 555 const char *name; 556 struct device dev; 557 unsigned out_epnum; 558 unsigned in_epnum; 559 560 unsigned sg_supported:1; 561 unsigned is_otg:1; 562 unsigned is_a_peripheral:1; 563 unsigned b_hnp_enable:1; 564 unsigned a_hnp_support:1; 565 unsigned a_alt_hnp_support:1; 566 unsigned quirk_ep_out_aligned_size:1; 567 unsigned is_selfpowered:1; 568 }; 569 #define work_to_gadget(w) (container_of((w), struct usb_gadget, work)) 570 571 static inline void set_gadget_data(struct usb_gadget *gadget, void *data) 572 { dev_set_drvdata(&gadget->dev, data); } 573 static inline void *get_gadget_data(struct usb_gadget *gadget) 574 { return dev_get_drvdata(&gadget->dev); } 575 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev) 576 { 577 return container_of(dev, struct usb_gadget, dev); 578 } 579 580 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */ 581 #define gadget_for_each_ep(tmp, gadget) \ 582 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list) 583 584 585 /** 586 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget 587 * requires quirk_ep_out_aligned_size, otherwise reguens len. 588 * @g: controller to check for quirk 589 * @ep: the endpoint whose maxpacketsize is used to align @len 590 * @len: buffer size's length to align to @ep's maxpacketsize 591 * 592 * This helper is used in case it's required for any reason to check and maybe 593 * align buffer's size to an ep's maxpacketsize. 594 */ 595 static inline size_t 596 usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len) 597 { 598 return !g->quirk_ep_out_aligned_size ? len : 599 round_up(len, (size_t)ep->desc->wMaxPacketSize); 600 } 601 602 /** 603 * gadget_is_dualspeed - return true iff the hardware handles high speed 604 * @g: controller that might support both high and full speeds 605 */ 606 static inline int gadget_is_dualspeed(struct usb_gadget *g) 607 { 608 return g->max_speed >= USB_SPEED_HIGH; 609 } 610 611 /** 612 * gadget_is_superspeed() - return true if the hardware handles superspeed 613 * @g: controller that might support superspeed 614 */ 615 static inline int gadget_is_superspeed(struct usb_gadget *g) 616 { 617 return g->max_speed >= USB_SPEED_SUPER; 618 } 619 620 /** 621 * gadget_is_otg - return true iff the hardware is OTG-ready 622 * @g: controller that might have a Mini-AB connector 623 * 624 * This is a runtime test, since kernels with a USB-OTG stack sometimes 625 * run on boards which only have a Mini-B (or Mini-A) connector. 626 */ 627 static inline int gadget_is_otg(struct usb_gadget *g) 628 { 629 #ifdef CONFIG_USB_OTG 630 return g->is_otg; 631 #else 632 return 0; 633 #endif 634 } 635 636 /** 637 * usb_gadget_frame_number - returns the current frame number 638 * @gadget: controller that reports the frame number 639 * 640 * Returns the usb frame number, normally eleven bits from a SOF packet, 641 * or negative errno if this device doesn't support this capability. 642 */ 643 static inline int usb_gadget_frame_number(struct usb_gadget *gadget) 644 { 645 return gadget->ops->get_frame(gadget); 646 } 647 648 /** 649 * usb_gadget_wakeup - tries to wake up the host connected to this gadget 650 * @gadget: controller used to wake up the host 651 * 652 * Returns zero on success, else negative error code if the hardware 653 * doesn't support such attempts, or its support has not been enabled 654 * by the usb host. Drivers must return device descriptors that report 655 * their ability to support this, or hosts won't enable it. 656 * 657 * This may also try to use SRP to wake the host and start enumeration, 658 * even if OTG isn't otherwise in use. OTG devices may also start 659 * remote wakeup even when hosts don't explicitly enable it. 660 */ 661 static inline int usb_gadget_wakeup(struct usb_gadget *gadget) 662 { 663 if (!gadget->ops->wakeup) 664 return -EOPNOTSUPP; 665 return gadget->ops->wakeup(gadget); 666 } 667 668 /** 669 * usb_gadget_set_selfpowered - sets the device selfpowered feature. 670 * @gadget:the device being declared as self-powered 671 * 672 * this affects the device status reported by the hardware driver 673 * to reflect that it now has a local power supply. 674 * 675 * returns zero on success, else negative errno. 676 */ 677 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget) 678 { 679 if (!gadget->ops->set_selfpowered) 680 return -EOPNOTSUPP; 681 return gadget->ops->set_selfpowered(gadget, 1); 682 } 683 684 /** 685 * usb_gadget_clear_selfpowered - clear the device selfpowered feature. 686 * @gadget:the device being declared as bus-powered 687 * 688 * this affects the device status reported by the hardware driver. 689 * some hardware may not support bus-powered operation, in which 690 * case this feature's value can never change. 691 * 692 * returns zero on success, else negative errno. 693 */ 694 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget) 695 { 696 if (!gadget->ops->set_selfpowered) 697 return -EOPNOTSUPP; 698 return gadget->ops->set_selfpowered(gadget, 0); 699 } 700 701 /** 702 * usb_gadget_vbus_connect - Notify controller that VBUS is powered 703 * @gadget:The device which now has VBUS power. 704 * Context: can sleep 705 * 706 * This call is used by a driver for an external transceiver (or GPIO) 707 * that detects a VBUS power session starting. Common responses include 708 * resuming the controller, activating the D+ (or D-) pullup to let the 709 * host detect that a USB device is attached, and starting to draw power 710 * (8mA or possibly more, especially after SET_CONFIGURATION). 711 * 712 * Returns zero on success, else negative errno. 713 */ 714 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget) 715 { 716 if (!gadget->ops->vbus_session) 717 return -EOPNOTSUPP; 718 return gadget->ops->vbus_session(gadget, 1); 719 } 720 721 /** 722 * usb_gadget_vbus_draw - constrain controller's VBUS power usage 723 * @gadget:The device whose VBUS usage is being described 724 * @mA:How much current to draw, in milliAmperes. This should be twice 725 * the value listed in the configuration descriptor bMaxPower field. 726 * 727 * This call is used by gadget drivers during SET_CONFIGURATION calls, 728 * reporting how much power the device may consume. For example, this 729 * could affect how quickly batteries are recharged. 730 * 731 * Returns zero on success, else negative errno. 732 */ 733 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA) 734 { 735 if (!gadget->ops->vbus_draw) 736 return -EOPNOTSUPP; 737 return gadget->ops->vbus_draw(gadget, mA); 738 } 739 740 /** 741 * usb_gadget_vbus_disconnect - notify controller about VBUS session end 742 * @gadget:the device whose VBUS supply is being described 743 * Context: can sleep 744 * 745 * This call is used by a driver for an external transceiver (or GPIO) 746 * that detects a VBUS power session ending. Common responses include 747 * reversing everything done in usb_gadget_vbus_connect(). 748 * 749 * Returns zero on success, else negative errno. 750 */ 751 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget) 752 { 753 if (!gadget->ops->vbus_session) 754 return -EOPNOTSUPP; 755 return gadget->ops->vbus_session(gadget, 0); 756 } 757 758 /** 759 * usb_gadget_connect - software-controlled connect to USB host 760 * @gadget:the peripheral being connected 761 * 762 * Enables the D+ (or potentially D-) pullup. The host will start 763 * enumerating this gadget when the pullup is active and a VBUS session 764 * is active (the link is powered). This pullup is always enabled unless 765 * usb_gadget_disconnect() has been used to disable it. 766 * 767 * Returns zero on success, else negative errno. 768 */ 769 static inline int usb_gadget_connect(struct usb_gadget *gadget) 770 { 771 if (!gadget->ops->pullup) 772 return -EOPNOTSUPP; 773 return gadget->ops->pullup(gadget, 1); 774 } 775 776 /** 777 * usb_gadget_disconnect - software-controlled disconnect from USB host 778 * @gadget:the peripheral being disconnected 779 * 780 * Disables the D+ (or potentially D-) pullup, which the host may see 781 * as a disconnect (when a VBUS session is active). Not all systems 782 * support software pullup controls. 783 * 784 * This routine may be used during the gadget driver bind() call to prevent 785 * the peripheral from ever being visible to the USB host, unless later 786 * usb_gadget_connect() is called. For example, user mode components may 787 * need to be activated before the system can talk to hosts. 788 * 789 * Returns zero on success, else negative errno. 790 */ 791 static inline int usb_gadget_disconnect(struct usb_gadget *gadget) 792 { 793 if (!gadget->ops->pullup) 794 return -EOPNOTSUPP; 795 return gadget->ops->pullup(gadget, 0); 796 } 797 798 799 /*-------------------------------------------------------------------------*/ 800 801 /** 802 * struct usb_gadget_driver - driver for usb 'slave' devices 803 * @function: String describing the gadget's function 804 * @max_speed: Highest speed the driver handles. 805 * @setup: Invoked for ep0 control requests that aren't handled by 806 * the hardware level driver. Most calls must be handled by 807 * the gadget driver, including descriptor and configuration 808 * management. The 16 bit members of the setup data are in 809 * USB byte order. Called in_interrupt; this may not sleep. Driver 810 * queues a response to ep0, or returns negative to stall. 811 * @disconnect: Invoked after all transfers have been stopped, 812 * when the host is disconnected. May be called in_interrupt; this 813 * may not sleep. Some devices can't detect disconnect, so this might 814 * not be called except as part of controller shutdown. 815 * @bind: the driver's bind callback 816 * @unbind: Invoked when the driver is unbound from a gadget, 817 * usually from rmmod (after a disconnect is reported). 818 * Called in a context that permits sleeping. 819 * @suspend: Invoked on USB suspend. May be called in_interrupt. 820 * @resume: Invoked on USB resume. May be called in_interrupt. 821 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers 822 * and should be called in_interrupt. 823 * @driver: Driver model state for this driver. 824 * 825 * Devices are disabled till a gadget driver successfully bind()s, which 826 * means the driver will handle setup() requests needed to enumerate (and 827 * meet "chapter 9" requirements) then do some useful work. 828 * 829 * If gadget->is_otg is true, the gadget driver must provide an OTG 830 * descriptor during enumeration, or else fail the bind() call. In such 831 * cases, no USB traffic may flow until both bind() returns without 832 * having called usb_gadget_disconnect(), and the USB host stack has 833 * initialized. 834 * 835 * Drivers use hardware-specific knowledge to configure the usb hardware. 836 * endpoint addressing is only one of several hardware characteristics that 837 * are in descriptors the ep0 implementation returns from setup() calls. 838 * 839 * Except for ep0 implementation, most driver code shouldn't need change to 840 * run on top of different usb controllers. It'll use endpoints set up by 841 * that ep0 implementation. 842 * 843 * The usb controller driver handles a few standard usb requests. Those 844 * include set_address, and feature flags for devices, interfaces, and 845 * endpoints (the get_status, set_feature, and clear_feature requests). 846 * 847 * Accordingly, the driver's setup() callback must always implement all 848 * get_descriptor requests, returning at least a device descriptor and 849 * a configuration descriptor. Drivers must make sure the endpoint 850 * descriptors match any hardware constraints. Some hardware also constrains 851 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3). 852 * 853 * The driver's setup() callback must also implement set_configuration, 854 * and should also implement set_interface, get_configuration, and 855 * get_interface. Setting a configuration (or interface) is where 856 * endpoints should be activated or (config 0) shut down. 857 * 858 * (Note that only the default control endpoint is supported. Neither 859 * hosts nor devices generally support control traffic except to ep0.) 860 * 861 * Most devices will ignore USB suspend/resume operations, and so will 862 * not provide those callbacks. However, some may need to change modes 863 * when the host is not longer directing those activities. For example, 864 * local controls (buttons, dials, etc) may need to be re-enabled since 865 * the (remote) host can't do that any longer; or an error state might 866 * be cleared, to make the device behave identically whether or not 867 * power is maintained. 868 */ 869 struct usb_gadget_driver { 870 char *function; 871 enum usb_device_speed max_speed; 872 int (*bind)(struct usb_gadget *gadget, 873 struct usb_gadget_driver *driver); 874 void (*unbind)(struct usb_gadget *); 875 int (*setup)(struct usb_gadget *, 876 const struct usb_ctrlrequest *); 877 void (*disconnect)(struct usb_gadget *); 878 void (*suspend)(struct usb_gadget *); 879 void (*resume)(struct usb_gadget *); 880 void (*reset)(struct usb_gadget *); 881 882 /* FIXME support safe rmmod */ 883 struct device_driver driver; 884 }; 885 886 887 888 /*-------------------------------------------------------------------------*/ 889 890 /* driver modules register and unregister, as usual. 891 * these calls must be made in a context that can sleep. 892 * 893 * these will usually be implemented directly by the hardware-dependent 894 * usb bus interface driver, which will only support a single driver. 895 */ 896 897 /** 898 * usb_gadget_probe_driver - probe a gadget driver 899 * @driver: the driver being registered 900 * Context: can sleep 901 * 902 * Call this in your gadget driver's module initialization function, 903 * to tell the underlying usb controller driver about your driver. 904 * The @bind() function will be called to bind it to a gadget before this 905 * registration call returns. It's expected that the @bind() function will 906 * be in init sections. 907 */ 908 int usb_gadget_probe_driver(struct usb_gadget_driver *driver); 909 910 /** 911 * usb_gadget_unregister_driver - unregister a gadget driver 912 * @driver:the driver being unregistered 913 * Context: can sleep 914 * 915 * Call this in your gadget driver's module cleanup function, 916 * to tell the underlying usb controller that your driver is 917 * going away. If the controller is connected to a USB host, 918 * it will first disconnect(). The driver is also requested 919 * to unbind() and clean up any device state, before this procedure 920 * finally returns. It's expected that the unbind() functions 921 * will in in exit sections, so may not be linked in some kernels. 922 */ 923 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver); 924 925 extern int usb_add_gadget_udc_release(struct device *parent, 926 struct usb_gadget *gadget, void (*release)(struct device *dev)); 927 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget); 928 extern void usb_del_gadget_udc(struct usb_gadget *gadget); 929 extern int usb_udc_attach_driver(const char *name, 930 struct usb_gadget_driver *driver); 931 932 /*-------------------------------------------------------------------------*/ 933 934 /* utility to simplify dealing with string descriptors */ 935 936 /** 937 * struct usb_string - wraps a C string and its USB id 938 * @id:the (nonzero) ID for this string 939 * @s:the string, in UTF-8 encoding 940 * 941 * If you're using usb_gadget_get_string(), use this to wrap a string 942 * together with its ID. 943 */ 944 struct usb_string { 945 u8 id; 946 const char *s; 947 }; 948 949 /** 950 * struct usb_gadget_strings - a set of USB strings in a given language 951 * @language:identifies the strings' language (0x0409 for en-us) 952 * @strings:array of strings with their ids 953 * 954 * If you're using usb_gadget_get_string(), use this to wrap all the 955 * strings for a given language. 956 */ 957 struct usb_gadget_strings { 958 u16 language; /* 0x0409 for en-us */ 959 struct usb_string *strings; 960 }; 961 962 struct usb_gadget_string_container { 963 struct list_head list; 964 u8 *stash[0]; 965 }; 966 967 /* put descriptor for string with that id into buf (buflen >= 256) */ 968 int usb_gadget_get_string(struct usb_gadget_strings *table, int id, u8 *buf); 969 970 /*-------------------------------------------------------------------------*/ 971 972 /* utility to simplify managing config descriptors */ 973 974 /* write vector of descriptors into buffer */ 975 int usb_descriptor_fillbuf(void *, unsigned, 976 const struct usb_descriptor_header **); 977 978 /* build config descriptor from single descriptor vector */ 979 int usb_gadget_config_buf(const struct usb_config_descriptor *config, 980 void *buf, unsigned buflen, const struct usb_descriptor_header **desc); 981 982 /* copy a NULL-terminated vector of descriptors */ 983 struct usb_descriptor_header **usb_copy_descriptors( 984 struct usb_descriptor_header **); 985 986 /** 987 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors() 988 * @v: vector of descriptors 989 */ 990 static inline void usb_free_descriptors(struct usb_descriptor_header **v) 991 { 992 kfree(v); 993 } 994 995 struct usb_function; 996 int usb_assign_descriptors(struct usb_function *f, 997 struct usb_descriptor_header **fs, 998 struct usb_descriptor_header **hs, 999 struct usb_descriptor_header **ss); 1000 void usb_free_all_descriptors(struct usb_function *f); 1001 1002 /*-------------------------------------------------------------------------*/ 1003 1004 /* utility to simplify map/unmap of usb_requests to/from DMA */ 1005 1006 extern int usb_gadget_map_request(struct usb_gadget *gadget, 1007 struct usb_request *req, int is_in); 1008 1009 extern void usb_gadget_unmap_request(struct usb_gadget *gadget, 1010 struct usb_request *req, int is_in); 1011 1012 /*-------------------------------------------------------------------------*/ 1013 1014 /* utility to set gadget state properly */ 1015 1016 extern void usb_gadget_set_state(struct usb_gadget *gadget, 1017 enum usb_device_state state); 1018 1019 /*-------------------------------------------------------------------------*/ 1020 1021 /* utility to tell udc core that the bus reset occurs */ 1022 extern void usb_gadget_udc_reset(struct usb_gadget *gadget, 1023 struct usb_gadget_driver *driver); 1024 1025 /*-------------------------------------------------------------------------*/ 1026 1027 /* utility to give requests back to the gadget layer */ 1028 1029 extern void usb_gadget_giveback_request(struct usb_ep *ep, 1030 struct usb_request *req); 1031 1032 1033 /*-------------------------------------------------------------------------*/ 1034 1035 /* utility wrapping a simple endpoint selection policy */ 1036 1037 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *, 1038 struct usb_endpoint_descriptor *); 1039 1040 1041 extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *, 1042 struct usb_endpoint_descriptor *, 1043 struct usb_ss_ep_comp_descriptor *); 1044 1045 extern void usb_ep_autoconfig_reset(struct usb_gadget *); 1046 1047 #endif /* __LINUX_USB_GADGET_H */ 1048