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   1// SPDX-License-Identifier: GPL-2.0
   2/**
   3 * udc.c - Core UDC Framework
   4 *
   5 * Copyright (C) 2010 Texas Instruments
   6 * Author: Felipe Balbi <balbi@ti.com>
   7 */
   8
   9#include <linux/kernel.h>
  10#include <linux/module.h>
  11#include <linux/device.h>
  12#include <linux/list.h>
  13#include <linux/err.h>
  14#include <linux/dma-mapping.h>
  15#include <linux/sched/task_stack.h>
  16#include <linux/workqueue.h>
  17
  18#include <linux/usb/ch9.h>
  19#include <linux/usb/gadget.h>
  20#include <linux/usb.h>
  21
  22#include "trace.h"
  23
  24/**
  25 * struct usb_udc - describes one usb device controller
  26 * @driver - the gadget driver pointer. For use by the class code
  27 * @dev - the child device to the actual controller
  28 * @gadget - the gadget. For use by the class code
  29 * @list - for use by the udc class driver
  30 * @vbus - for udcs who care about vbus status, this value is real vbus status;
  31 * for udcs who do not care about vbus status, this value is always true
  32 *
  33 * This represents the internal data structure which is used by the UDC-class
  34 * to hold information about udc driver and gadget together.
  35 */
  36struct usb_udc {
  37	struct usb_gadget_driver	*driver;
  38	struct usb_gadget		*gadget;
  39	struct device			dev;
  40	struct list_head		list;
  41	bool				vbus;
  42};
  43
  44static struct class *udc_class;
  45static LIST_HEAD(udc_list);
  46static LIST_HEAD(gadget_driver_pending_list);
  47static DEFINE_MUTEX(udc_lock);
  48
  49static int udc_bind_to_driver(struct usb_udc *udc,
  50		struct usb_gadget_driver *driver);
  51
  52/* ------------------------------------------------------------------------- */
  53
  54/**
  55 * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
  56 * @ep:the endpoint being configured
  57 * @maxpacket_limit:value of maximum packet size limit
  58 *
  59 * This function should be used only in UDC drivers to initialize endpoint
  60 * (usually in probe function).
  61 */
  62void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
  63					      unsigned maxpacket_limit)
  64{
  65	ep->maxpacket_limit = maxpacket_limit;
  66	ep->maxpacket = maxpacket_limit;
  67
  68	trace_usb_ep_set_maxpacket_limit(ep, 0);
  69}
  70EXPORT_SYMBOL_GPL(usb_ep_set_maxpacket_limit);
  71
  72/**
  73 * usb_ep_enable - configure endpoint, making it usable
  74 * @ep:the endpoint being configured.  may not be the endpoint named "ep0".
  75 *	drivers discover endpoints through the ep_list of a usb_gadget.
  76 *
  77 * When configurations are set, or when interface settings change, the driver
  78 * will enable or disable the relevant endpoints.  while it is enabled, an
  79 * endpoint may be used for i/o until the driver receives a disconnect() from
  80 * the host or until the endpoint is disabled.
  81 *
  82 * the ep0 implementation (which calls this routine) must ensure that the
  83 * hardware capabilities of each endpoint match the descriptor provided
  84 * for it.  for example, an endpoint named "ep2in-bulk" would be usable
  85 * for interrupt transfers as well as bulk, but it likely couldn't be used
  86 * for iso transfers or for endpoint 14.  some endpoints are fully
  87 * configurable, with more generic names like "ep-a".  (remember that for
  88 * USB, "in" means "towards the USB master".)
  89 *
  90 * This routine must be called in process context.
  91 *
  92 * returns zero, or a negative error code.
  93 */
  94int usb_ep_enable(struct usb_ep *ep)
  95{
  96	int ret = 0;
  97
  98	if (ep->enabled)
  99		goto out;
 100
 101	/* UDC drivers can't handle endpoints with maxpacket size 0 */
 102	if (usb_endpoint_maxp(ep->desc) == 0) {
 103		/*
 104		 * We should log an error message here, but we can't call
 105		 * dev_err() because there's no way to find the gadget
 106		 * given only ep.
 107		 */
 108		ret = -EINVAL;
 109		goto out;
 110	}
 111
 112	ret = ep->ops->enable(ep, ep->desc);
 113	if (ret)
 114		goto out;
 115
 116	ep->enabled = true;
 117
 118out:
 119	trace_usb_ep_enable(ep, ret);
 120
 121	return ret;
 122}
 123EXPORT_SYMBOL_GPL(usb_ep_enable);
 124
 125/**
 126 * usb_ep_disable - endpoint is no longer usable
 127 * @ep:the endpoint being unconfigured.  may not be the endpoint named "ep0".
 128 *
 129 * no other task may be using this endpoint when this is called.
 130 * any pending and uncompleted requests will complete with status
 131 * indicating disconnect (-ESHUTDOWN) before this call returns.
 132 * gadget drivers must call usb_ep_enable() again before queueing
 133 * requests to the endpoint.
 134 *
 135 * This routine must be called in process context.
 136 *
 137 * returns zero, or a negative error code.
 138 */
 139int usb_ep_disable(struct usb_ep *ep)
 140{
 141	int ret = 0;
 142
 143	if (!ep->enabled)
 144		goto out;
 145
 146	ret = ep->ops->disable(ep);
 147	if (ret)
 148		goto out;
 149
 150	ep->enabled = false;
 151
 152out:
 153	trace_usb_ep_disable(ep, ret);
 154
 155	return ret;
 156}
 157EXPORT_SYMBOL_GPL(usb_ep_disable);
 158
 159/**
 160 * usb_ep_alloc_request - allocate a request object to use with this endpoint
 161 * @ep:the endpoint to be used with with the request
 162 * @gfp_flags:GFP_* flags to use
 163 *
 164 * Request objects must be allocated with this call, since they normally
 165 * need controller-specific setup and may even need endpoint-specific
 166 * resources such as allocation of DMA descriptors.
 167 * Requests may be submitted with usb_ep_queue(), and receive a single
 168 * completion callback.  Free requests with usb_ep_free_request(), when
 169 * they are no longer needed.
 170 *
 171 * Returns the request, or null if one could not be allocated.
 172 */
 173struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
 174						       gfp_t gfp_flags)
 175{
 176	struct usb_request *req = NULL;
 177
 178	req = ep->ops->alloc_request(ep, gfp_flags);
 179
 180	trace_usb_ep_alloc_request(ep, req, req ? 0 : -ENOMEM);
 181
 182	return req;
 183}
 184EXPORT_SYMBOL_GPL(usb_ep_alloc_request);
 185
 186/**
 187 * usb_ep_free_request - frees a request object
 188 * @ep:the endpoint associated with the request
 189 * @req:the request being freed
 190 *
 191 * Reverses the effect of usb_ep_alloc_request().
 192 * Caller guarantees the request is not queued, and that it will
 193 * no longer be requeued (or otherwise used).
 194 */
 195void usb_ep_free_request(struct usb_ep *ep,
 196				       struct usb_request *req)
 197{
 198	trace_usb_ep_free_request(ep, req, 0);
 199	ep->ops->free_request(ep, req);
 200}
 201EXPORT_SYMBOL_GPL(usb_ep_free_request);
 202
 203/**
 204 * usb_ep_queue - queues (submits) an I/O request to an endpoint.
 205 * @ep:the endpoint associated with the request
 206 * @req:the request being submitted
 207 * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
 208 *	pre-allocate all necessary memory with the request.
 209 *
 210 * This tells the device controller to perform the specified request through
 211 * that endpoint (reading or writing a buffer).  When the request completes,
 212 * including being canceled by usb_ep_dequeue(), the request's completion
 213 * routine is called to return the request to the driver.  Any endpoint
 214 * (except control endpoints like ep0) may have more than one transfer
 215 * request queued; they complete in FIFO order.  Once a gadget driver
 216 * submits a request, that request may not be examined or modified until it
 217 * is given back to that driver through the completion callback.
 218 *
 219 * Each request is turned into one or more packets.  The controller driver
 220 * never merges adjacent requests into the same packet.  OUT transfers
 221 * will sometimes use data that's already buffered in the hardware.
 222 * Drivers can rely on the fact that the first byte of the request's buffer
 223 * always corresponds to the first byte of some USB packet, for both
 224 * IN and OUT transfers.
 225 *
 226 * Bulk endpoints can queue any amount of data; the transfer is packetized
 227 * automatically.  The last packet will be short if the request doesn't fill it
 228 * out completely.  Zero length packets (ZLPs) should be avoided in portable
 229 * protocols since not all usb hardware can successfully handle zero length
 230 * packets.  (ZLPs may be explicitly written, and may be implicitly written if
 231 * the request 'zero' flag is set.)  Bulk endpoints may also be used
 232 * for interrupt transfers; but the reverse is not true, and some endpoints
 233 * won't support every interrupt transfer.  (Such as 768 byte packets.)
 234 *
 235 * Interrupt-only endpoints are less functional than bulk endpoints, for
 236 * example by not supporting queueing or not handling buffers that are
 237 * larger than the endpoint's maxpacket size.  They may also treat data
 238 * toggle differently.
 239 *
 240 * Control endpoints ... after getting a setup() callback, the driver queues
 241 * one response (even if it would be zero length).  That enables the
 242 * status ack, after transferring data as specified in the response.  Setup
 243 * functions may return negative error codes to generate protocol stalls.
 244 * (Note that some USB device controllers disallow protocol stall responses
 245 * in some cases.)  When control responses are deferred (the response is
 246 * written after the setup callback returns), then usb_ep_set_halt() may be
 247 * used on ep0 to trigger protocol stalls.  Depending on the controller,
 248 * it may not be possible to trigger a status-stage protocol stall when the
 249 * data stage is over, that is, from within the response's completion
 250 * routine.
 251 *
 252 * For periodic endpoints, like interrupt or isochronous ones, the usb host
 253 * arranges to poll once per interval, and the gadget driver usually will
 254 * have queued some data to transfer at that time.
 255 *
 256 * Note that @req's ->complete() callback must never be called from
 257 * within usb_ep_queue() as that can create deadlock situations.
 258 *
 259 * This routine may be called in interrupt context.
 260 *
 261 * Returns zero, or a negative error code.  Endpoints that are not enabled
 262 * report errors; errors will also be
 263 * reported when the usb peripheral is disconnected.
 264 *
 265 * If and only if @req is successfully queued (the return value is zero),
 266 * @req->complete() will be called exactly once, when the Gadget core and
 267 * UDC are finished with the request.  When the completion function is called,
 268 * control of the request is returned to the device driver which submitted it.
 269 * The completion handler may then immediately free or reuse @req.
 270 */
 271int usb_ep_queue(struct usb_ep *ep,
 272			       struct usb_request *req, gfp_t gfp_flags)
 273{
 274	int ret = 0;
 275
 276	if (WARN_ON_ONCE(!ep->enabled && ep->address)) {
 277		ret = -ESHUTDOWN;
 278		goto out;
 279	}
 280
 281	ret = ep->ops->queue(ep, req, gfp_flags);
 282
 283out:
 284	trace_usb_ep_queue(ep, req, ret);
 285
 286	return ret;
 287}
 288EXPORT_SYMBOL_GPL(usb_ep_queue);
 289
 290/**
 291 * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
 292 * @ep:the endpoint associated with the request
 293 * @req:the request being canceled
 294 *
 295 * If the request is still active on the endpoint, it is dequeued and
 296 * eventually its completion routine is called (with status -ECONNRESET);
 297 * else a negative error code is returned.  This routine is asynchronous,
 298 * that is, it may return before the completion routine runs.
 299 *
 300 * Note that some hardware can't clear out write fifos (to unlink the request
 301 * at the head of the queue) except as part of disconnecting from usb. Such
 302 * restrictions prevent drivers from supporting configuration changes,
 303 * even to configuration zero (a "chapter 9" requirement).
 304 *
 305 * This routine may be called in interrupt context.
 306 */
 307int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
 308{
 309	int ret;
 310
 311	ret = ep->ops->dequeue(ep, req);
 312	trace_usb_ep_dequeue(ep, req, ret);
 313
 314	return ret;
 315}
 316EXPORT_SYMBOL_GPL(usb_ep_dequeue);
 317
 318/**
 319 * usb_ep_set_halt - sets the endpoint halt feature.
 320 * @ep: the non-isochronous endpoint being stalled
 321 *
 322 * Use this to stall an endpoint, perhaps as an error report.
 323 * Except for control endpoints,
 324 * the endpoint stays halted (will not stream any data) until the host
 325 * clears this feature; drivers may need to empty the endpoint's request
 326 * queue first, to make sure no inappropriate transfers happen.
 327 *
 328 * Note that while an endpoint CLEAR_FEATURE will be invisible to the
 329 * gadget driver, a SET_INTERFACE will not be.  To reset endpoints for the
 330 * current altsetting, see usb_ep_clear_halt().  When switching altsettings,
 331 * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
 332 *
 333 * This routine may be called in interrupt context.
 334 *
 335 * Returns zero, or a negative error code.  On success, this call sets
 336 * underlying hardware state that blocks data transfers.
 337 * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
 338 * transfer requests are still queued, or if the controller hardware
 339 * (usually a FIFO) still holds bytes that the host hasn't collected.
 340 */
 341int usb_ep_set_halt(struct usb_ep *ep)
 342{
 343	int ret;
 344
 345	ret = ep->ops->set_halt(ep, 1);
 346	trace_usb_ep_set_halt(ep, ret);
 347
 348	return ret;
 349}
 350EXPORT_SYMBOL_GPL(usb_ep_set_halt);
 351
 352/**
 353 * usb_ep_clear_halt - clears endpoint halt, and resets toggle
 354 * @ep:the bulk or interrupt endpoint being reset
 355 *
 356 * Use this when responding to the standard usb "set interface" request,
 357 * for endpoints that aren't reconfigured, after clearing any other state
 358 * in the endpoint's i/o queue.
 359 *
 360 * This routine may be called in interrupt context.
 361 *
 362 * Returns zero, or a negative error code.  On success, this call clears
 363 * the underlying hardware state reflecting endpoint halt and data toggle.
 364 * Note that some hardware can't support this request (like pxa2xx_udc),
 365 * and accordingly can't correctly implement interface altsettings.
 366 */
 367int usb_ep_clear_halt(struct usb_ep *ep)
 368{
 369	int ret;
 370
 371	ret = ep->ops->set_halt(ep, 0);
 372	trace_usb_ep_clear_halt(ep, ret);
 373
 374	return ret;
 375}
 376EXPORT_SYMBOL_GPL(usb_ep_clear_halt);
 377
 378/**
 379 * usb_ep_set_wedge - sets the halt feature and ignores clear requests
 380 * @ep: the endpoint being wedged
 381 *
 382 * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT)
 383 * requests. If the gadget driver clears the halt status, it will
 384 * automatically unwedge the endpoint.
 385 *
 386 * This routine may be called in interrupt context.
 387 *
 388 * Returns zero on success, else negative errno.
 389 */
 390int usb_ep_set_wedge(struct usb_ep *ep)
 391{
 392	int ret;
 393
 394	if (ep->ops->set_wedge)
 395		ret = ep->ops->set_wedge(ep);
 396	else
 397		ret = ep->ops->set_halt(ep, 1);
 398
 399	trace_usb_ep_set_wedge(ep, ret);
 400
 401	return ret;
 402}
 403EXPORT_SYMBOL_GPL(usb_ep_set_wedge);
 404
 405/**
 406 * usb_ep_fifo_status - returns number of bytes in fifo, or error
 407 * @ep: the endpoint whose fifo status is being checked.
 408 *
 409 * FIFO endpoints may have "unclaimed data" in them in certain cases,
 410 * such as after aborted transfers.  Hosts may not have collected all
 411 * the IN data written by the gadget driver (and reported by a request
 412 * completion).  The gadget driver may not have collected all the data
 413 * written OUT to it by the host.  Drivers that need precise handling for
 414 * fault reporting or recovery may need to use this call.
 415 *
 416 * This routine may be called in interrupt context.
 417 *
 418 * This returns the number of such bytes in the fifo, or a negative
 419 * errno if the endpoint doesn't use a FIFO or doesn't support such
 420 * precise handling.
 421 */
 422int usb_ep_fifo_status(struct usb_ep *ep)
 423{
 424	int ret;
 425
 426	if (ep->ops->fifo_status)
 427		ret = ep->ops->fifo_status(ep);
 428	else
 429		ret = -EOPNOTSUPP;
 430
 431	trace_usb_ep_fifo_status(ep, ret);
 432
 433	return ret;
 434}
 435EXPORT_SYMBOL_GPL(usb_ep_fifo_status);
 436
 437/**
 438 * usb_ep_fifo_flush - flushes contents of a fifo
 439 * @ep: the endpoint whose fifo is being flushed.
 440 *
 441 * This call may be used to flush the "unclaimed data" that may exist in
 442 * an endpoint fifo after abnormal transaction terminations.  The call
 443 * must never be used except when endpoint is not being used for any
 444 * protocol translation.
 445 *
 446 * This routine may be called in interrupt context.
 447 */
 448void usb_ep_fifo_flush(struct usb_ep *ep)
 449{
 450	if (ep->ops->fifo_flush)
 451		ep->ops->fifo_flush(ep);
 452
 453	trace_usb_ep_fifo_flush(ep, 0);
 454}
 455EXPORT_SYMBOL_GPL(usb_ep_fifo_flush);
 456
 457/* ------------------------------------------------------------------------- */
 458
 459/**
 460 * usb_gadget_frame_number - returns the current frame number
 461 * @gadget: controller that reports the frame number
 462 *
 463 * Returns the usb frame number, normally eleven bits from a SOF packet,
 464 * or negative errno if this device doesn't support this capability.
 465 */
 466int usb_gadget_frame_number(struct usb_gadget *gadget)
 467{
 468	int ret;
 469
 470	ret = gadget->ops->get_frame(gadget);
 471
 472	trace_usb_gadget_frame_number(gadget, ret);
 473
 474	return ret;
 475}
 476EXPORT_SYMBOL_GPL(usb_gadget_frame_number);
 477
 478/**
 479 * usb_gadget_wakeup - tries to wake up the host connected to this gadget
 480 * @gadget: controller used to wake up the host
 481 *
 482 * Returns zero on success, else negative error code if the hardware
 483 * doesn't support such attempts, or its support has not been enabled
 484 * by the usb host.  Drivers must return device descriptors that report
 485 * their ability to support this, or hosts won't enable it.
 486 *
 487 * This may also try to use SRP to wake the host and start enumeration,
 488 * even if OTG isn't otherwise in use.  OTG devices may also start
 489 * remote wakeup even when hosts don't explicitly enable it.
 490 */
 491int usb_gadget_wakeup(struct usb_gadget *gadget)
 492{
 493	int ret = 0;
 494
 495	if (!gadget->ops->wakeup) {
 496		ret = -EOPNOTSUPP;
 497		goto out;
 498	}
 499
 500	ret = gadget->ops->wakeup(gadget);
 501
 502out:
 503	trace_usb_gadget_wakeup(gadget, ret);
 504
 505	return ret;
 506}
 507EXPORT_SYMBOL_GPL(usb_gadget_wakeup);
 508
 509/**
 510 * usb_gadget_set_selfpowered - sets the device selfpowered feature.
 511 * @gadget:the device being declared as self-powered
 512 *
 513 * this affects the device status reported by the hardware driver
 514 * to reflect that it now has a local power supply.
 515 *
 516 * returns zero on success, else negative errno.
 517 */
 518int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
 519{
 520	int ret = 0;
 521
 522	if (!gadget->ops->set_selfpowered) {
 523		ret = -EOPNOTSUPP;
 524		goto out;
 525	}
 526
 527	ret = gadget->ops->set_selfpowered(gadget, 1);
 528
 529out:
 530	trace_usb_gadget_set_selfpowered(gadget, ret);
 531
 532	return ret;
 533}
 534EXPORT_SYMBOL_GPL(usb_gadget_set_selfpowered);
 535
 536/**
 537 * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
 538 * @gadget:the device being declared as bus-powered
 539 *
 540 * this affects the device status reported by the hardware driver.
 541 * some hardware may not support bus-powered operation, in which
 542 * case this feature's value can never change.
 543 *
 544 * returns zero on success, else negative errno.
 545 */
 546int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
 547{
 548	int ret = 0;
 549
 550	if (!gadget->ops->set_selfpowered) {
 551		ret = -EOPNOTSUPP;
 552		goto out;
 553	}
 554
 555	ret = gadget->ops->set_selfpowered(gadget, 0);
 556
 557out:
 558	trace_usb_gadget_clear_selfpowered(gadget, ret);
 559
 560	return ret;
 561}
 562EXPORT_SYMBOL_GPL(usb_gadget_clear_selfpowered);
 563
 564/**
 565 * usb_gadget_vbus_connect - Notify controller that VBUS is powered
 566 * @gadget:The device which now has VBUS power.
 567 * Context: can sleep
 568 *
 569 * This call is used by a driver for an external transceiver (or GPIO)
 570 * that detects a VBUS power session starting.  Common responses include
 571 * resuming the controller, activating the D+ (or D-) pullup to let the
 572 * host detect that a USB device is attached, and starting to draw power
 573 * (8mA or possibly more, especially after SET_CONFIGURATION).
 574 *
 575 * Returns zero on success, else negative errno.
 576 */
 577int usb_gadget_vbus_connect(struct usb_gadget *gadget)
 578{
 579	int ret = 0;
 580
 581	if (!gadget->ops->vbus_session) {
 582		ret = -EOPNOTSUPP;
 583		goto out;
 584	}
 585
 586	ret = gadget->ops->vbus_session(gadget, 1);
 587
 588out:
 589	trace_usb_gadget_vbus_connect(gadget, ret);
 590
 591	return ret;
 592}
 593EXPORT_SYMBOL_GPL(usb_gadget_vbus_connect);
 594
 595/**
 596 * usb_gadget_vbus_draw - constrain controller's VBUS power usage
 597 * @gadget:The device whose VBUS usage is being described
 598 * @mA:How much current to draw, in milliAmperes.  This should be twice
 599 *	the value listed in the configuration descriptor bMaxPower field.
 600 *
 601 * This call is used by gadget drivers during SET_CONFIGURATION calls,
 602 * reporting how much power the device may consume.  For example, this
 603 * could affect how quickly batteries are recharged.
 604 *
 605 * Returns zero on success, else negative errno.
 606 */
 607int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
 608{
 609	int ret = 0;
 610
 611	if (!gadget->ops->vbus_draw) {
 612		ret = -EOPNOTSUPP;
 613		goto out;
 614	}
 615
 616	ret = gadget->ops->vbus_draw(gadget, mA);
 617	if (!ret)
 618		gadget->mA = mA;
 619
 620out:
 621	trace_usb_gadget_vbus_draw(gadget, ret);
 622
 623	return ret;
 624}
 625EXPORT_SYMBOL_GPL(usb_gadget_vbus_draw);
 626
 627/**
 628 * usb_gadget_vbus_disconnect - notify controller about VBUS session end
 629 * @gadget:the device whose VBUS supply is being described
 630 * Context: can sleep
 631 *
 632 * This call is used by a driver for an external transceiver (or GPIO)
 633 * that detects a VBUS power session ending.  Common responses include
 634 * reversing everything done in usb_gadget_vbus_connect().
 635 *
 636 * Returns zero on success, else negative errno.
 637 */
 638int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
 639{
 640	int ret = 0;
 641
 642	if (!gadget->ops->vbus_session) {
 643		ret = -EOPNOTSUPP;
 644		goto out;
 645	}
 646
 647	ret = gadget->ops->vbus_session(gadget, 0);
 648
 649out:
 650	trace_usb_gadget_vbus_disconnect(gadget, ret);
 651
 652	return ret;
 653}
 654EXPORT_SYMBOL_GPL(usb_gadget_vbus_disconnect);
 655
 656/**
 657 * usb_gadget_connect - software-controlled connect to USB host
 658 * @gadget:the peripheral being connected
 659 *
 660 * Enables the D+ (or potentially D-) pullup.  The host will start
 661 * enumerating this gadget when the pullup is active and a VBUS session
 662 * is active (the link is powered).  This pullup is always enabled unless
 663 * usb_gadget_disconnect() has been used to disable it.
 664 *
 665 * Returns zero on success, else negative errno.
 666 */
 667int usb_gadget_connect(struct usb_gadget *gadget)
 668{
 669	int ret = 0;
 670
 671	if (!gadget->ops->pullup) {
 672		ret = -EOPNOTSUPP;
 673		goto out;
 674	}
 675
 676	if (gadget->deactivated) {
 677		/*
 678		 * If gadget is deactivated we only save new state.
 679		 * Gadget will be connected automatically after activation.
 680		 */
 681		gadget->connected = true;
 682		goto out;
 683	}
 684
 685	ret = gadget->ops->pullup(gadget, 1);
 686	if (!ret)
 687		gadget->connected = 1;
 688
 689out:
 690	trace_usb_gadget_connect(gadget, ret);
 691
 692	return ret;
 693}
 694EXPORT_SYMBOL_GPL(usb_gadget_connect);
 695
 696/**
 697 * usb_gadget_disconnect - software-controlled disconnect from USB host
 698 * @gadget:the peripheral being disconnected
 699 *
 700 * Disables the D+ (or potentially D-) pullup, which the host may see
 701 * as a disconnect (when a VBUS session is active).  Not all systems
 702 * support software pullup controls.
 703 *
 704 * Following a successful disconnect, invoke the ->disconnect() callback
 705 * for the current gadget driver so that UDC drivers don't need to.
 706 *
 707 * Returns zero on success, else negative errno.
 708 */
 709int usb_gadget_disconnect(struct usb_gadget *gadget)
 710{
 711	int ret = 0;
 712
 713	if (!gadget->ops->pullup) {
 714		ret = -EOPNOTSUPP;
 715		goto out;
 716	}
 717
 718	if (gadget->deactivated) {
 719		/*
 720		 * If gadget is deactivated we only save new state.
 721		 * Gadget will stay disconnected after activation.
 722		 */
 723		gadget->connected = false;
 724		goto out;
 725	}
 726
 727	ret = gadget->ops->pullup(gadget, 0);
 728	if (!ret) {
 729		gadget->connected = 0;
 730		gadget->udc->driver->disconnect(gadget);
 731	}
 732
 733out:
 734	trace_usb_gadget_disconnect(gadget, ret);
 735
 736	return ret;
 737}
 738EXPORT_SYMBOL_GPL(usb_gadget_disconnect);
 739
 740/**
 741 * usb_gadget_deactivate - deactivate function which is not ready to work
 742 * @gadget: the peripheral being deactivated
 743 *
 744 * This routine may be used during the gadget driver bind() call to prevent
 745 * the peripheral from ever being visible to the USB host, unless later
 746 * usb_gadget_activate() is called.  For example, user mode components may
 747 * need to be activated before the system can talk to hosts.
 748 *
 749 * Returns zero on success, else negative errno.
 750 */
 751int usb_gadget_deactivate(struct usb_gadget *gadget)
 752{
 753	int ret = 0;
 754
 755	if (gadget->deactivated)
 756		goto out;
 757
 758	if (gadget->connected) {
 759		ret = usb_gadget_disconnect(gadget);
 760		if (ret)
 761			goto out;
 762
 763		/*
 764		 * If gadget was being connected before deactivation, we want
 765		 * to reconnect it in usb_gadget_activate().
 766		 */
 767		gadget->connected = true;
 768	}
 769	gadget->deactivated = true;
 770
 771out:
 772	trace_usb_gadget_deactivate(gadget, ret);
 773
 774	return ret;
 775}
 776EXPORT_SYMBOL_GPL(usb_gadget_deactivate);
 777
 778/**
 779 * usb_gadget_activate - activate function which is not ready to work
 780 * @gadget: the peripheral being activated
 781 *
 782 * This routine activates gadget which was previously deactivated with
 783 * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed.
 784 *
 785 * Returns zero on success, else negative errno.
 786 */
 787int usb_gadget_activate(struct usb_gadget *gadget)
 788{
 789	int ret = 0;
 790
 791	if (!gadget->deactivated)
 792		goto out;
 793
 794	gadget->deactivated = false;
 795
 796	/*
 797	 * If gadget has been connected before deactivation, or became connected
 798	 * while it was being deactivated, we call usb_gadget_connect().
 799	 */
 800	if (gadget->connected)
 801		ret = usb_gadget_connect(gadget);
 802
 803out:
 804	trace_usb_gadget_activate(gadget, ret);
 805
 806	return ret;
 807}
 808EXPORT_SYMBOL_GPL(usb_gadget_activate);
 809
 810/* ------------------------------------------------------------------------- */
 811
 812#ifdef	CONFIG_HAS_DMA
 813
 814int usb_gadget_map_request_by_dev(struct device *dev,
 815		struct usb_request *req, int is_in)
 816{
 817	if (req->length == 0)
 818		return 0;
 819
 820	if (req->num_sgs) {
 821		int     mapped;
 822
 823		mapped = dma_map_sg(dev, req->sg, req->num_sgs,
 824				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 825		if (mapped == 0) {
 826			dev_err(dev, "failed to map SGs\n");
 827			return -EFAULT;
 828		}
 829
 830		req->num_mapped_sgs = mapped;
 831	} else {
 832		if (is_vmalloc_addr(req->buf)) {
 833			dev_err(dev, "buffer is not dma capable\n");
 834			return -EFAULT;
 835		} else if (object_is_on_stack(req->buf)) {
 836			dev_err(dev, "buffer is on stack\n");
 837			return -EFAULT;
 838		}
 839
 840		req->dma = dma_map_single(dev, req->buf, req->length,
 841				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 842
 843		if (dma_mapping_error(dev, req->dma)) {
 844			dev_err(dev, "failed to map buffer\n");
 845			return -EFAULT;
 846		}
 847
 848		req->dma_mapped = 1;
 849	}
 850
 851	return 0;
 852}
 853EXPORT_SYMBOL_GPL(usb_gadget_map_request_by_dev);
 854
 855int usb_gadget_map_request(struct usb_gadget *gadget,
 856		struct usb_request *req, int is_in)
 857{
 858	return usb_gadget_map_request_by_dev(gadget->dev.parent, req, is_in);
 859}
 860EXPORT_SYMBOL_GPL(usb_gadget_map_request);
 861
 862void usb_gadget_unmap_request_by_dev(struct device *dev,
 863		struct usb_request *req, int is_in)
 864{
 865	if (req->length == 0)
 866		return;
 867
 868	if (req->num_mapped_sgs) {
 869		dma_unmap_sg(dev, req->sg, req->num_sgs,
 870				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 871
 872		req->num_mapped_sgs = 0;
 873	} else if (req->dma_mapped) {
 874		dma_unmap_single(dev, req->dma, req->length,
 875				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 876		req->dma_mapped = 0;
 877	}
 878}
 879EXPORT_SYMBOL_GPL(usb_gadget_unmap_request_by_dev);
 880
 881void usb_gadget_unmap_request(struct usb_gadget *gadget,
 882		struct usb_request *req, int is_in)
 883{
 884	usb_gadget_unmap_request_by_dev(gadget->dev.parent, req, is_in);
 885}
 886EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);
 887
 888#endif	/* CONFIG_HAS_DMA */
 889
 890/* ------------------------------------------------------------------------- */
 891
 892/**
 893 * usb_gadget_giveback_request - give the request back to the gadget layer
 894 * Context: in_interrupt()
 895 *
 896 * This is called by device controller drivers in order to return the
 897 * completed request back to the gadget layer.
 898 */
 899void usb_gadget_giveback_request(struct usb_ep *ep,
 900		struct usb_request *req)
 901{
 902	if (likely(req->status == 0))
 903		usb_led_activity(USB_LED_EVENT_GADGET);
 904
 905	trace_usb_gadget_giveback_request(ep, req, 0);
 906
 907	req->complete(ep, req);
 908}
 909EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
 910
 911/* ------------------------------------------------------------------------- */
 912
 913/**
 914 * gadget_find_ep_by_name - returns ep whose name is the same as sting passed
 915 *	in second parameter or NULL if searched endpoint not found
 916 * @g: controller to check for quirk
 917 * @name: name of searched endpoint
 918 */
 919struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g, const char *name)
 920{
 921	struct usb_ep *ep;
 922
 923	gadget_for_each_ep(ep, g) {
 924		if (!strcmp(ep->name, name))
 925			return ep;
 926	}
 927
 928	return NULL;
 929}
 930EXPORT_SYMBOL_GPL(gadget_find_ep_by_name);
 931
 932/* ------------------------------------------------------------------------- */
 933
 934int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
 935		struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
 936		struct usb_ss_ep_comp_descriptor *ep_comp)
 937{
 938	u8		type;
 939	u16		max;
 940	int		num_req_streams = 0;
 941
 942	/* endpoint already claimed? */
 943	if (ep->claimed)
 944		return 0;
 945
 946	type = usb_endpoint_type(desc);
 947	max = usb_endpoint_maxp(desc);
 948
 949	if (usb_endpoint_dir_in(desc) && !ep->caps.dir_in)
 950		return 0;
 951	if (usb_endpoint_dir_out(desc) && !ep->caps.dir_out)
 952		return 0;
 953
 954	if (max > ep->maxpacket_limit)
 955		return 0;
 956
 957	/* "high bandwidth" works only at high speed */
 958	if (!gadget_is_dualspeed(gadget) && usb_endpoint_maxp_mult(desc) > 1)
 959		return 0;
 960
 961	switch (type) {
 962	case USB_ENDPOINT_XFER_CONTROL:
 963		/* only support ep0 for portable CONTROL traffic */
 964		return 0;
 965	case USB_ENDPOINT_XFER_ISOC:
 966		if (!ep->caps.type_iso)
 967			return 0;
 968		/* ISO:  limit 1023 bytes full speed, 1024 high/super speed */
 969		if (!gadget_is_dualspeed(gadget) && max > 1023)
 970			return 0;
 971		break;
 972	case USB_ENDPOINT_XFER_BULK:
 973		if (!ep->caps.type_bulk)
 974			return 0;
 975		if (ep_comp && gadget_is_superspeed(gadget)) {
 976			/* Get the number of required streams from the
 977			 * EP companion descriptor and see if the EP
 978			 * matches it
 979			 */
 980			num_req_streams = ep_comp->bmAttributes & 0x1f;
 981			if (num_req_streams > ep->max_streams)
 982				return 0;
 983		}
 984		break;
 985	case USB_ENDPOINT_XFER_INT:
 986		/* Bulk endpoints handle interrupt transfers,
 987		 * except the toggle-quirky iso-synch kind
 988		 */
 989		if (!ep->caps.type_int && !ep->caps.type_bulk)
 990			return 0;
 991		/* INT:  limit 64 bytes full speed, 1024 high/super speed */
 992		if (!gadget_is_dualspeed(gadget) && max > 64)
 993			return 0;
 994		break;
 995	}
 996
 997	return 1;
 998}
 999EXPORT_SYMBOL_GPL(usb_gadget_ep_match_desc);
1000
1001/* ------------------------------------------------------------------------- */
1002
1003static void usb_gadget_state_work(struct work_struct *work)
1004{
1005	struct usb_gadget *gadget = work_to_gadget(work);
1006	struct usb_udc *udc = gadget->udc;
1007
1008	if (udc)
1009		sysfs_notify(&udc->dev.kobj, NULL, "state");
1010}
1011
1012void usb_gadget_set_state(struct usb_gadget *gadget,
1013		enum usb_device_state state)
1014{
1015	gadget->state = state;
1016	schedule_work(&gadget->work);
1017}
1018EXPORT_SYMBOL_GPL(usb_gadget_set_state);
1019
1020/* ------------------------------------------------------------------------- */
1021
1022static void usb_udc_connect_control(struct usb_udc *udc)
1023{
1024	if (udc->vbus)
1025		usb_gadget_connect(udc->gadget);
1026	else
1027		usb_gadget_disconnect(udc->gadget);
1028}
1029
1030/**
1031 * usb_udc_vbus_handler - updates the udc core vbus status, and try to
1032 * connect or disconnect gadget
1033 * @gadget: The gadget which vbus change occurs
1034 * @status: The vbus status
1035 *
1036 * The udc driver calls it when it wants to connect or disconnect gadget
1037 * according to vbus status.
1038 */
1039void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status)
1040{
1041	struct usb_udc *udc = gadget->udc;
1042
1043	if (udc) {
1044		udc->vbus = status;
1045		usb_udc_connect_control(udc);
1046	}
1047}
1048EXPORT_SYMBOL_GPL(usb_udc_vbus_handler);
1049
1050/**
1051 * usb_gadget_udc_reset - notifies the udc core that bus reset occurs
1052 * @gadget: The gadget which bus reset occurs
1053 * @driver: The gadget driver we want to notify
1054 *
1055 * If the udc driver has bus reset handler, it needs to call this when the bus
1056 * reset occurs, it notifies the gadget driver that the bus reset occurs as
1057 * well as updates gadget state.
1058 */
1059void usb_gadget_udc_reset(struct usb_gadget *gadget,
1060		struct usb_gadget_driver *driver)
1061{
1062	driver->reset(gadget);
1063	usb_gadget_set_state(gadget, USB_STATE_DEFAULT);
1064}
1065EXPORT_SYMBOL_GPL(usb_gadget_udc_reset);
1066
1067/**
1068 * usb_gadget_udc_start - tells usb device controller to start up
1069 * @udc: The UDC to be started
1070 *
1071 * This call is issued by the UDC Class driver when it's about
1072 * to register a gadget driver to the device controller, before
1073 * calling gadget driver's bind() method.
1074 *
1075 * It allows the controller to be powered off until strictly
1076 * necessary to have it powered on.
1077 *
1078 * Returns zero on success, else negative errno.
1079 */
1080static inline int usb_gadget_udc_start(struct usb_udc *udc)
1081{
1082	return udc->gadget->ops->udc_start(udc->gadget, udc->driver);
1083}
1084
1085/**
1086 * usb_gadget_udc_stop - tells usb device controller we don't need it anymore
1087 * @gadget: The device we want to stop activity
1088 * @driver: The driver to unbind from @gadget
1089 *
1090 * This call is issued by the UDC Class driver after calling
1091 * gadget driver's unbind() method.
1092 *
1093 * The details are implementation specific, but it can go as
1094 * far as powering off UDC completely and disable its data
1095 * line pullups.
1096 */
1097static inline void usb_gadget_udc_stop(struct usb_udc *udc)
1098{
1099	udc->gadget->ops->udc_stop(udc->gadget);
1100}
1101
1102/**
1103 * usb_gadget_udc_set_speed - tells usb device controller speed supported by
1104 *    current driver
1105 * @udc: The device we want to set maximum speed
1106 * @speed: The maximum speed to allowed to run
1107 *
1108 * This call is issued by the UDC Class driver before calling
1109 * usb_gadget_udc_start() in order to make sure that we don't try to
1110 * connect on speeds the gadget driver doesn't support.
1111 */
1112static inline void usb_gadget_udc_set_speed(struct usb_udc *udc,
1113					    enum usb_device_speed speed)
1114{
1115	if (udc->gadget->ops->udc_set_speed) {
1116		enum usb_device_speed s;
1117
1118		s = min(speed, udc->gadget->max_speed);
1119		udc->gadget->ops->udc_set_speed(udc->gadget, s);
1120	}
1121}
1122
1123/**
1124 * usb_udc_release - release the usb_udc struct
1125 * @dev: the dev member within usb_udc
1126 *
1127 * This is called by driver's core in order to free memory once the last
1128 * reference is released.
1129 */
1130static void usb_udc_release(struct device *dev)
1131{
1132	struct usb_udc *udc;
1133
1134	udc = container_of(dev, struct usb_udc, dev);
1135	dev_dbg(dev, "releasing '%s'\n", dev_name(dev));
1136	kfree(udc);
1137}
1138
1139static const struct attribute_group *usb_udc_attr_groups[];
1140
1141static void usb_udc_nop_release(struct device *dev)
1142{
1143	dev_vdbg(dev, "%s\n", __func__);
1144}
1145
1146/* should be called with udc_lock held */
1147static int check_pending_gadget_drivers(struct usb_udc *udc)
1148{
1149	struct usb_gadget_driver *driver;
1150	int ret = 0;
1151
1152	list_for_each_entry(driver, &gadget_driver_pending_list, pending)
1153		if (!driver->udc_name || strcmp(driver->udc_name,
1154						dev_name(&udc->dev)) == 0) {
1155			ret = udc_bind_to_driver(udc, driver);
1156			if (ret != -EPROBE_DEFER)
1157				list_del_init(&driver->pending);
1158			break;
1159		}
1160
1161	return ret;
1162}
1163
1164/**
1165 * usb_add_gadget_udc_release - adds a new gadget to the udc class driver list
1166 * @parent: the parent device to this udc. Usually the controller driver's
1167 * device.
1168 * @gadget: the gadget to be added to the list.
1169 * @release: a gadget release function.
1170 *
1171 * Returns zero on success, negative errno otherwise.
1172 * Calls the gadget release function in the latter case.
1173 */
1174int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
1175		void (*release)(struct device *dev))
1176{
1177	struct usb_udc		*udc;
1178	int			ret = -ENOMEM;
1179
1180	dev_set_name(&gadget->dev, "gadget");
1181	INIT_WORK(&gadget->work, usb_gadget_state_work);
1182	gadget->dev.parent = parent;
1183
1184	if (release)
1185		gadget->dev.release = release;
1186	else
1187		gadget->dev.release = usb_udc_nop_release;
1188
1189	device_initialize(&gadget->dev);
1190
1191	udc = kzalloc(sizeof(*udc), GFP_KERNEL);
1192	if (!udc)
1193		goto err_put_gadget;
1194
1195	device_initialize(&udc->dev);
1196	udc->dev.release = usb_udc_release;
1197	udc->dev.class = udc_class;
1198	udc->dev.groups = usb_udc_attr_groups;
1199	udc->dev.parent = parent;
1200	ret = dev_set_name(&udc->dev, "%s", kobject_name(&parent->kobj));
1201	if (ret)
1202		goto err_put_udc;
1203
1204	ret = device_add(&gadget->dev);
1205	if (ret)
1206		goto err_put_udc;
1207
1208	udc->gadget = gadget;
1209	gadget->udc = udc;
1210
1211	mutex_lock(&udc_lock);
1212	list_add_tail(&udc->list, &udc_list);
1213
1214	ret = device_add(&udc->dev);
1215	if (ret)
1216		goto err_unlist_udc;
1217
1218	usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
1219	udc->vbus = true;
1220
1221	/* pick up one of pending gadget drivers */
1222	ret = check_pending_gadget_drivers(udc);
1223	if (ret)
1224		goto err_del_udc;
1225
1226	mutex_unlock(&udc_lock);
1227
1228	return 0;
1229
1230 err_del_udc:
1231	device_del(&udc->dev);
1232
1233 err_unlist_udc:
1234	list_del(&udc->list);
1235	mutex_unlock(&udc_lock);
1236
1237	device_del(&gadget->dev);
1238
1239 err_put_udc:
1240	put_device(&udc->dev);
1241
1242 err_put_gadget:
1243	put_device(&gadget->dev);
1244	return ret;
1245}
1246EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release);
1247
1248/**
1249 * usb_get_gadget_udc_name - get the name of the first UDC controller
1250 * This functions returns the name of the first UDC controller in the system.
1251 * Please note that this interface is usefull only for legacy drivers which
1252 * assume that there is only one UDC controller in the system and they need to
1253 * get its name before initialization. There is no guarantee that the UDC
1254 * of the returned name will be still available, when gadget driver registers
1255 * itself.
1256 *
1257 * Returns pointer to string with UDC controller name on success, NULL
1258 * otherwise. Caller should kfree() returned string.
1259 */
1260char *usb_get_gadget_udc_name(void)
1261{
1262	struct usb_udc *udc;
1263	char *name = NULL;
1264
1265	/* For now we take the first available UDC */
1266	mutex_lock(&udc_lock);
1267	list_for_each_entry(udc, &udc_list, list) {
1268		if (!udc->driver) {
1269			name = kstrdup(udc->gadget->name, GFP_KERNEL);
1270			break;
1271		}
1272	}
1273	mutex_unlock(&udc_lock);
1274	return name;
1275}
1276EXPORT_SYMBOL_GPL(usb_get_gadget_udc_name);
1277
1278/**
1279 * usb_add_gadget_udc - adds a new gadget to the udc class driver list
1280 * @parent: the parent device to this udc. Usually the controller
1281 * driver's device.
1282 * @gadget: the gadget to be added to the list
1283 *
1284 * Returns zero on success, negative errno otherwise.
1285 */
1286int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
1287{
1288	return usb_add_gadget_udc_release(parent, gadget, NULL);
1289}
1290EXPORT_SYMBOL_GPL(usb_add_gadget_udc);
1291
1292static void usb_gadget_remove_driver(struct usb_udc *udc)
1293{
1294	dev_dbg(&udc->dev, "unregistering UDC driver [%s]\n",
1295			udc->driver->function);
1296
1297	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
1298
1299	usb_gadget_disconnect(udc->gadget);
1300	udc->driver->unbind(udc->gadget);
1301	usb_gadget_udc_stop(udc);
1302
1303	udc->driver = NULL;
1304	udc->dev.driver = NULL;
1305	udc->gadget->dev.driver = NULL;
1306}
1307
1308/**
1309 * usb_del_gadget_udc - deletes @udc from udc_list
1310 * @gadget: the gadget to be removed.
1311 *
1312 * This, will call usb_gadget_unregister_driver() if
1313 * the @udc is still busy.
1314 */
1315void usb_del_gadget_udc(struct usb_gadget *gadget)
1316{
1317	struct usb_udc *udc = gadget->udc;
1318
1319	if (!udc)
1320		return;
1321
1322	dev_vdbg(gadget->dev.parent, "unregistering gadget\n");
1323
1324	mutex_lock(&udc_lock);
1325	list_del(&udc->list);
1326
1327	if (udc->driver) {
1328		struct usb_gadget_driver *driver = udc->driver;
1329
1330		usb_gadget_remove_driver(udc);
1331		list_add(&driver->pending, &gadget_driver_pending_list);
1332	}
1333	mutex_unlock(&udc_lock);
1334
1335	kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
1336	flush_work(&gadget->work);
1337	device_unregister(&udc->dev);
1338	device_unregister(&gadget->dev);
1339	memset(&gadget->dev, 0x00, sizeof(gadget->dev));
1340}
1341EXPORT_SYMBOL_GPL(usb_del_gadget_udc);
1342
1343/* ------------------------------------------------------------------------- */
1344
1345static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *driver)
1346{
1347	int ret;
1348
1349	dev_dbg(&udc->dev, "registering UDC driver [%s]\n",
1350			driver->function);
1351
1352	udc->driver = driver;
1353	udc->dev.driver = &driver->driver;
1354	udc->gadget->dev.driver = &driver->driver;
1355
1356	usb_gadget_udc_set_speed(udc, driver->max_speed);
1357
1358	ret = driver->bind(udc->gadget, driver);
1359	if (ret)
1360		goto err1;
1361	ret = usb_gadget_udc_start(udc);
1362	if (ret) {
1363		driver->unbind(udc->gadget);
1364		goto err1;
1365	}
1366	usb_udc_connect_control(udc);
1367
1368	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
1369	return 0;
1370err1:
1371	if (ret != -EISNAM)
1372		dev_err(&udc->dev, "failed to start %s: %d\n",
1373			udc->driver->function, ret);
1374	udc->driver = NULL;
1375	udc->dev.driver = NULL;
1376	udc->gadget->dev.driver = NULL;
1377	return ret;
1378}
1379
1380int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
1381{
1382	struct usb_udc		*udc = NULL;
1383	int			ret = -ENODEV;
1384
1385	if (!driver || !driver->bind || !driver->setup)
1386		return -EINVAL;
1387
1388	mutex_lock(&udc_lock);
1389	if (driver->udc_name) {
1390		list_for_each_entry(udc, &udc_list, list) {
1391			ret = strcmp(driver->udc_name, dev_name(&udc->dev));
1392			if (!ret)
1393				break;
1394		}
1395		if (ret)
1396			ret = -ENODEV;
1397		else if (udc->driver)
1398			ret = -EBUSY;
1399		else
1400			goto found;
1401	} else {
1402		list_for_each_entry(udc, &udc_list, list) {
1403			/* For now we take the first one */
1404			if (!udc->driver)
1405				goto found;
1406		}
1407	}
1408
1409	if (!driver->match_existing_only) {
1410		list_add_tail(&driver->pending, &gadget_driver_pending_list);
1411		pr_info("udc-core: couldn't find an available UDC - added [%s] to list of pending drivers\n",
1412			driver->function);
1413		ret = 0;
1414	}
1415
1416	mutex_unlock(&udc_lock);
1417	return ret;
1418found:
1419	ret = udc_bind_to_driver(udc, driver);
1420	mutex_unlock(&udc_lock);
1421	return ret;
1422}
1423EXPORT_SYMBOL_GPL(usb_gadget_probe_driver);
1424
1425int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
1426{
1427	struct usb_udc		*udc = NULL;
1428	int			ret = -ENODEV;
1429
1430	if (!driver || !driver->unbind)
1431		return -EINVAL;
1432
1433	mutex_lock(&udc_lock);
1434	list_for_each_entry(udc, &udc_list, list) {
1435		if (udc->driver == driver) {
1436			usb_gadget_remove_driver(udc);
1437			usb_gadget_set_state(udc->gadget,
1438					     USB_STATE_NOTATTACHED);
1439
1440			/* Maybe there is someone waiting for this UDC? */
1441			check_pending_gadget_drivers(udc);
1442			/*
1443			 * For now we ignore bind errors as probably it's
1444			 * not a valid reason to fail other's gadget unbind
1445			 */
1446			ret = 0;
1447			break;
1448		}
1449	}
1450
1451	if (ret) {
1452		list_del(&driver->pending);
1453		ret = 0;
1454	}
1455	mutex_unlock(&udc_lock);
1456	return ret;
1457}
1458EXPORT_SYMBOL_GPL(usb_gadget_unregister_driver);
1459
1460/* ------------------------------------------------------------------------- */
1461
1462static ssize_t srp_store(struct device *dev,
1463		struct device_attribute *attr, const char *buf, size_t n)
1464{
1465	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
1466
1467	if (sysfs_streq(buf, "1"))
1468		usb_gadget_wakeup(udc->gadget);
1469
1470	return n;
1471}
1472static DEVICE_ATTR_WO(srp);
1473
1474static ssize_t soft_connect_store(struct device *dev,
1475		struct device_attribute *attr, const char *buf, size_t n)
1476{
1477	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
1478
1479	if (!udc->driver) {
1480		dev_err(dev, "soft-connect without a gadget driver\n");
1481		return -EOPNOTSUPP;
1482	}
1483
1484	if (sysfs_streq(buf, "connect")) {
1485		usb_gadget_udc_start(udc);
1486		usb_gadget_connect(udc->gadget);
1487	} else if (sysfs_streq(buf, "disconnect")) {
1488		usb_gadget_disconnect(udc->gadget);
1489		usb_gadget_udc_stop(udc);
1490	} else {
1491		dev_err(dev, "unsupported command '%s'\n", buf);
1492		return -EINVAL;
1493	}
1494
1495	return n;
1496}
1497static DEVICE_ATTR_WO(soft_connect);
1498
1499static ssize_t state_show(struct device *dev, struct device_attribute *attr,
1500			  char *buf)
1501{
1502	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
1503	struct usb_gadget	*gadget = udc->gadget;
1504
1505	return sprintf(buf, "%s\n", usb_state_string(gadget->state));
1506}
1507static DEVICE_ATTR_RO(state);
1508
1509static ssize_t function_show(struct device *dev, struct device_attribute *attr,
1510			     char *buf)
1511{
1512	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
1513	struct usb_gadget_driver *drv = udc->driver;
1514
1515	if (!drv || !drv->function)
1516		return 0;
1517	return scnprintf(buf, PAGE_SIZE, "%s\n", drv->function);
1518}
1519static DEVICE_ATTR_RO(function);
1520
1521#define USB_UDC_SPEED_ATTR(name, param)					\
1522ssize_t name##_show(struct device *dev,					\
1523		struct device_attribute *attr, char *buf)		\
1524{									\
1525	struct usb_udc *udc = container_of(dev, struct usb_udc, dev);	\
1526	return scnprintf(buf, PAGE_SIZE, "%s\n",			\
1527			usb_speed_string(udc->gadget->param));		\
1528}									\
1529static DEVICE_ATTR_RO(name)
1530
1531static USB_UDC_SPEED_ATTR(current_speed, speed);
1532static USB_UDC_SPEED_ATTR(maximum_speed, max_speed);
1533
1534#define USB_UDC_ATTR(name)					\
1535ssize_t name##_show(struct device *dev,				\
1536		struct device_attribute *attr, char *buf)	\
1537{								\
1538	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev); \
1539	struct usb_gadget	*gadget = udc->gadget;		\
1540								\
1541	return scnprintf(buf, PAGE_SIZE, "%d\n", gadget->name);	\
1542}								\
1543static DEVICE_ATTR_RO(name)
1544
1545static USB_UDC_ATTR(is_otg);
1546static USB_UDC_ATTR(is_a_peripheral);
1547static USB_UDC_ATTR(b_hnp_enable);
1548static USB_UDC_ATTR(a_hnp_support);
1549static USB_UDC_ATTR(a_alt_hnp_support);
1550static USB_UDC_ATTR(is_selfpowered);
1551
1552static struct attribute *usb_udc_attrs[] = {
1553	&dev_attr_srp.attr,
1554	&dev_attr_soft_connect.attr,
1555	&dev_attr_state.attr,
1556	&dev_attr_function.attr,
1557	&dev_attr_current_speed.attr,
1558	&dev_attr_maximum_speed.attr,
1559
1560	&dev_attr_is_otg.attr,
1561	&dev_attr_is_a_peripheral.attr,
1562	&dev_attr_b_hnp_enable.attr,
1563	&dev_attr_a_hnp_support.attr,
1564	&dev_attr_a_alt_hnp_support.attr,
1565	&dev_attr_is_selfpowered.attr,
1566	NULL,
1567};
1568
1569static const struct attribute_group usb_udc_attr_group = {
1570	.attrs = usb_udc_attrs,
1571};
1572
1573static const struct attribute_group *usb_udc_attr_groups[] = {
1574	&usb_udc_attr_group,
1575	NULL,
1576};
1577
1578static int usb_udc_uevent(struct device *dev, struct kobj_uevent_env *env)
1579{
1580	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
1581	int			ret;
1582
1583	ret = add_uevent_var(env, "USB_UDC_NAME=%s", udc->gadget->name);
1584	if (ret) {
1585		dev_err(dev, "failed to add uevent USB_UDC_NAME\n");
1586		return ret;
1587	}
1588
1589	if (udc->driver) {
1590		ret = add_uevent_var(env, "USB_UDC_DRIVER=%s",
1591				udc->driver->function);
1592		if (ret) {
1593			dev_err(dev, "failed to add uevent USB_UDC_DRIVER\n");
1594			return ret;
1595		}
1596	}
1597
1598	return 0;
1599}
1600
1601static int __init usb_udc_init(void)
1602{
1603	udc_class = class_create(THIS_MODULE, "udc");
1604	if (IS_ERR(udc_class)) {
1605		pr_err("failed to create udc class --> %ld\n",
1606				PTR_ERR(udc_class));
1607		return PTR_ERR(udc_class);
1608	}
1609
1610	udc_class->dev_uevent = usb_udc_uevent;
1611	return 0;
1612}
1613subsys_initcall(usb_udc_init);
1614
1615static void __exit usb_udc_exit(void)
1616{
1617	class_destroy(udc_class);
1618}
1619module_exit(usb_udc_exit);
1620
1621MODULE_DESCRIPTION("UDC Framework");
1622MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
1623MODULE_LICENSE("GPL v2");