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