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 * @started: the UDC's started state. True if the UDC had started.
  33 *
  34 * This represents the internal data structure which is used by the UDC-class
  35 * to hold information about udc driver and gadget together.
  36 */
  37struct usb_udc {
  38        struct usb_gadget_driver        *driver;
  39        struct usb_gadget               *gadget;
  40        struct device                   dev;
  41        struct list_head                list;
  42        bool                            vbus;
  43        bool                            started;
  44};
  45
  46static struct class *udc_class;
  47static LIST_HEAD(udc_list);
  48static LIST_HEAD(gadget_driver_pending_list);
  49static DEFINE_MUTEX(udc_lock);
  50
  51static int udc_bind_to_driver(struct usb_udc *udc,
  52                struct usb_gadget_driver *driver);
  53
  54/* ------------------------------------------------------------------------- */
  55
  56/**
  57 * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
  58 * @ep:the endpoint being configured
  59 * @maxpacket_limit:value of maximum packet size limit
  60 *
  61 * This function should be used only in UDC drivers to initialize endpoint
  62 * (usually in probe function).
  63 */
  64void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
  65                                              unsigned maxpacket_limit)
  66{
  67        ep->maxpacket_limit = maxpacket_limit;
  68        ep->maxpacket = maxpacket_limit;
  69
  70        trace_usb_ep_set_maxpacket_limit(ep, 0);
  71}
  72EXPORT_SYMBOL_GPL(usb_ep_set_maxpacket_limit);
  73
  74/**
  75 * usb_ep_enable - configure endpoint, making it usable
  76 * @ep:the endpoint being configured.  may not be the endpoint named "ep0".
  77 *      drivers discover endpoints through the ep_list of a usb_gadget.
  78 *
  79 * When configurations are set, or when interface settings change, the driver
  80 * will enable or disable the relevant endpoints.  while it is enabled, an
  81 * endpoint may be used for i/o until the driver receives a disconnect() from
  82 * the host or until the endpoint is disabled.
  83 *
  84 * the ep0 implementation (which calls this routine) must ensure that the
  85 * hardware capabilities of each endpoint match the descriptor provided
  86 * for it.  for example, an endpoint named "ep2in-bulk" would be usable
  87 * for interrupt transfers as well as bulk, but it likely couldn't be used
  88 * for iso transfers or for endpoint 14.  some endpoints are fully
  89 * configurable, with more generic names like "ep-a".  (remember that for
  90 * USB, "in" means "towards the USB host".)
  91 *
  92 * This routine must be called in process context.
  93 *
  94 * returns zero, or a negative error code.
  95 */
  96int usb_ep_enable(struct usb_ep *ep)
  97{
  98        int ret = 0;
  99
 100        if (ep->enabled)
 101                goto out;
 102
 103        /* UDC drivers can't handle endpoints with maxpacket size 0 */
 104        if (usb_endpoint_maxp(ep->desc) == 0) {
 105                /*
 106                 * We should log an error message here, but we can't call
 107                 * dev_err() because there's no way to find the gadget
 108                 * given only ep.
 109                 */
 110                ret = -EINVAL;
 111                goto out;
 112        }
 113
 114        ret = ep->ops->enable(ep, ep->desc);
 115        if (ret)
 116                goto out;
 117
 118        ep->enabled = true;
 119
 120out:
 121        trace_usb_ep_enable(ep, ret);
 122
 123        return ret;
 124}
 125EXPORT_SYMBOL_GPL(usb_ep_enable);
 126
 127/**
 128 * usb_ep_disable - endpoint is no longer usable
 129 * @ep:the endpoint being unconfigured.  may not be the endpoint named "ep0".
 130 *
 131 * no other task may be using this endpoint when this is called.
 132 * any pending and uncompleted requests will complete with status
 133 * indicating disconnect (-ESHUTDOWN) before this call returns.
 134 * gadget drivers must call usb_ep_enable() again before queueing
 135 * requests to the endpoint.
 136 *
 137 * This routine must be called in process context.
 138 *
 139 * returns zero, or a negative error code.
 140 */
 141int usb_ep_disable(struct usb_ep *ep)
 142{
 143        int ret = 0;
 144
 145        if (!ep->enabled)
 146                goto out;
 147
 148        ret = ep->ops->disable(ep);
 149        if (ret)
 150                goto out;
 151
 152        ep->enabled = false;
 153
 154out:
 155        trace_usb_ep_disable(ep, ret);
 156
 157        return ret;
 158}
 159EXPORT_SYMBOL_GPL(usb_ep_disable);
 160
 161/**
 162 * usb_ep_alloc_request - allocate a request object to use with this endpoint
 163 * @ep:the endpoint to be used with with the request
 164 * @gfp_flags:GFP_* flags to use
 165 *
 166 * Request objects must be allocated with this call, since they normally
 167 * need controller-specific setup and may even need endpoint-specific
 168 * resources such as allocation of DMA descriptors.
 169 * Requests may be submitted with usb_ep_queue(), and receive a single
 170 * completion callback.  Free requests with usb_ep_free_request(), when
 171 * they are no longer needed.
 172 *
 173 * Returns the request, or null if one could not be allocated.
 174 */
 175struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
 176                                                       gfp_t gfp_flags)
 177{
 178        struct usb_request *req = NULL;
 179
 180        req = ep->ops->alloc_request(ep, gfp_flags);
 181
 182        trace_usb_ep_alloc_request(ep, req, req ? 0 : -ENOMEM);
 183
 184        return req;
 185}
 186EXPORT_SYMBOL_GPL(usb_ep_alloc_request);
 187
 188/**
 189 * usb_ep_free_request - frees a request object
 190 * @ep:the endpoint associated with the request
 191 * @req:the request being freed
 192 *
 193 * Reverses the effect of usb_ep_alloc_request().
 194 * Caller guarantees the request is not queued, and that it will
 195 * no longer be requeued (or otherwise used).
 196 */
 197void usb_ep_free_request(struct usb_ep *ep,
 198                                       struct usb_request *req)
 199{
 200        trace_usb_ep_free_request(ep, req, 0);
 201        ep->ops->free_request(ep, req);
 202}
 203EXPORT_SYMBOL_GPL(usb_ep_free_request);
 204
 205/**
 206 * usb_ep_queue - queues (submits) an I/O request to an endpoint.
 207 * @ep:the endpoint associated with the request
 208 * @req:the request being submitted
 209 * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
 210 *      pre-allocate all necessary memory with the request.
 211 *
 212 * This tells the device controller to perform the specified request through
 213 * that endpoint (reading or writing a buffer).  When the request completes,
 214 * including being canceled by usb_ep_dequeue(), the request's completion
 215 * routine is called to return the request to the driver.  Any endpoint
 216 * (except control endpoints like ep0) may have more than one transfer
 217 * request queued; they complete in FIFO order.  Once a gadget driver
 218 * submits a request, that request may not be examined or modified until it
 219 * is given back to that driver through the completion callback.
 220 *
 221 * Each request is turned into one or more packets.  The controller driver
 222 * never merges adjacent requests into the same packet.  OUT transfers
 223 * will sometimes use data that's already buffered in the hardware.
 224 * Drivers can rely on the fact that the first byte of the request's buffer
 225 * always corresponds to the first byte of some USB packet, for both
 226 * IN and OUT transfers.
 227 *
 228 * Bulk endpoints can queue any amount of data; the transfer is packetized
 229 * automatically.  The last packet will be short if the request doesn't fill it
 230 * out completely.  Zero length packets (ZLPs) should be avoided in portable
 231 * protocols since not all usb hardware can successfully handle zero length
 232 * packets.  (ZLPs may be explicitly written, and may be implicitly written if
 233 * the request 'zero' flag is set.)  Bulk endpoints may also be used
 234 * for interrupt transfers; but the reverse is not true, and some endpoints
 235 * won't support every interrupt transfer.  (Such as 768 byte packets.)
 236 *
 237 * Interrupt-only endpoints are less functional than bulk endpoints, for
 238 * example by not supporting queueing or not handling buffers that are
 239 * larger than the endpoint's maxpacket size.  They may also treat data
 240 * toggle differently.
 241 *
 242 * Control endpoints ... after getting a setup() callback, the driver queues
 243 * one response (even if it would be zero length).  That enables the
 244 * status ack, after transferring data as specified in the response.  Setup
 245 * functions may return negative error codes to generate protocol stalls.
 246 * (Note that some USB device controllers disallow protocol stall responses
 247 * in some cases.)  When control responses are deferred (the response is
 248 * written after the setup callback returns), then usb_ep_set_halt() may be
 249 * used on ep0 to trigger protocol stalls.  Depending on the controller,
 250 * it may not be possible to trigger a status-stage protocol stall when the
 251 * data stage is over, that is, from within the response's completion
 252 * routine.
 253 *
 254 * For periodic endpoints, like interrupt or isochronous ones, the usb host
 255 * arranges to poll once per interval, and the gadget driver usually will
 256 * have queued some data to transfer at that time.
 257 *
 258 * Note that @req's ->complete() callback must never be called from
 259 * within usb_ep_queue() as that can create deadlock situations.
 260 *
 261 * This routine may be called in interrupt context.
 262 *
 263 * Returns zero, or a negative error code.  Endpoints that are not enabled
 264 * report errors; errors will also be
 265 * reported when the usb peripheral is disconnected.
 266 *
 267 * If and only if @req is successfully queued (the return value is zero),
 268 * @req->complete() will be called exactly once, when the Gadget core and
 269 * UDC are finished with the request.  When the completion function is called,
 270 * control of the request is returned to the device driver which submitted it.
 271 * The completion handler may then immediately free or reuse @req.
 272 */
 273int usb_ep_queue(struct usb_ep *ep,
 274                               struct usb_request *req, gfp_t gfp_flags)
 275{
 276        int ret = 0;
 277
 278        if (WARN_ON_ONCE(!ep->enabled && ep->address)) {
 279                ret = -ESHUTDOWN;
 280                goto out;
 281        }
 282
 283        ret = ep->ops->queue(ep, req, gfp_flags);
 284
 285out:
 286        trace_usb_ep_queue(ep, req, ret);
 287
 288        return ret;
 289}
 290EXPORT_SYMBOL_GPL(usb_ep_queue);
 291
 292/**
 293 * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
 294 * @ep:the endpoint associated with the request
 295 * @req:the request being canceled
 296 *
 297 * If the request is still active on the endpoint, it is dequeued and
 298 * eventually its completion routine is called (with status -ECONNRESET);
 299 * else a negative error code is returned.  This routine is asynchronous,
 300 * that is, it may return before the completion routine runs.
 301 *
 302 * Note that some hardware can't clear out write fifos (to unlink the request
 303 * at the head of the queue) except as part of disconnecting from usb. Such
 304 * restrictions prevent drivers from supporting configuration changes,
 305 * even to configuration zero (a "chapter 9" requirement).
 306 *
 307 * This routine may be called in interrupt context.
 308 */
 309int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
 310{
 311        int ret;
 312
 313        ret = ep->ops->dequeue(ep, req);
 314        trace_usb_ep_dequeue(ep, req, ret);
 315
 316        return ret;
 317}
 318EXPORT_SYMBOL_GPL(usb_ep_dequeue);
 319
 320/**
 321 * usb_ep_set_halt - sets the endpoint halt feature.
 322 * @ep: the non-isochronous endpoint being stalled
 323 *
 324 * Use this to stall an endpoint, perhaps as an error report.
 325 * Except for control endpoints,
 326 * the endpoint stays halted (will not stream any data) until the host
 327 * clears this feature; drivers may need to empty the endpoint's request
 328 * queue first, to make sure no inappropriate transfers happen.
 329 *
 330 * Note that while an endpoint CLEAR_FEATURE will be invisible to the
 331 * gadget driver, a SET_INTERFACE will not be.  To reset endpoints for the
 332 * current altsetting, see usb_ep_clear_halt().  When switching altsettings,
 333 * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
 334 *
 335 * This routine may be called in interrupt context.
 336 *
 337 * Returns zero, or a negative error code.  On success, this call sets
 338 * underlying hardware state that blocks data transfers.
 339 * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
 340 * transfer requests are still queued, or if the controller hardware
 341 * (usually a FIFO) still holds bytes that the host hasn't collected.
 342 */
 343int usb_ep_set_halt(struct usb_ep *ep)
 344{
 345        int ret;
 346
 347        ret = ep->ops->set_halt(ep, 1);
 348        trace_usb_ep_set_halt(ep, ret);
 349
 350        return ret;
 351}
 352EXPORT_SYMBOL_GPL(usb_ep_set_halt);
 353
 354/**
 355 * usb_ep_clear_halt - clears endpoint halt, and resets toggle
 356 * @ep:the bulk or interrupt endpoint being reset
 357 *
 358 * Use this when responding to the standard usb "set interface" request,
 359 * for endpoints that aren't reconfigured, after clearing any other state
 360 * in the endpoint's i/o queue.
 361 *
 362 * This routine may be called in interrupt context.
 363 *
 364 * Returns zero, or a negative error code.  On success, this call clears
 365 * the underlying hardware state reflecting endpoint halt and data toggle.
 366 * Note that some hardware can't support this request (like pxa2xx_udc),
 367 * and accordingly can't correctly implement interface altsettings.
 368 */
 369int usb_ep_clear_halt(struct usb_ep *ep)
 370{
 371        int ret;
 372
 373        ret = ep->ops->set_halt(ep, 0);
 374        trace_usb_ep_clear_halt(ep, ret);
 375
 376        return ret;
 377}
 378EXPORT_SYMBOL_GPL(usb_ep_clear_halt);
 379
 380/**
 381 * usb_ep_set_wedge - sets the halt feature and ignores clear requests
 382 * @ep: the endpoint being wedged
 383 *
 384 * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT)
 385 * requests. If the gadget driver clears the halt status, it will
 386 * automatically unwedge the endpoint.
 387 *
 388 * This routine may be called in interrupt context.
 389 *
 390 * Returns zero on success, else negative errno.
 391 */
 392int usb_ep_set_wedge(struct usb_ep *ep)
 393{
 394        int ret;
 395
 396        if (ep->ops->set_wedge)
 397                ret = ep->ops->set_wedge(ep);
 398        else
 399                ret = ep->ops->set_halt(ep, 1);
 400
 401        trace_usb_ep_set_wedge(ep, ret);
 402
 403        return ret;
 404}
 405EXPORT_SYMBOL_GPL(usb_ep_set_wedge);
 406
 407/**
 408 * usb_ep_fifo_status - returns number of bytes in fifo, or error
 409 * @ep: the endpoint whose fifo status is being checked.
 410 *
 411 * FIFO endpoints may have "unclaimed data" in them in certain cases,
 412 * such as after aborted transfers.  Hosts may not have collected all
 413 * the IN data written by the gadget driver (and reported by a request
 414 * completion).  The gadget driver may not have collected all the data
 415 * written OUT to it by the host.  Drivers that need precise handling for
 416 * fault reporting or recovery may need to use this call.
 417 *
 418 * This routine may be called in interrupt context.
 419 *
 420 * This returns the number of such bytes in the fifo, or a negative
 421 * errno if the endpoint doesn't use a FIFO or doesn't support such
 422 * precise handling.
 423 */
 424int usb_ep_fifo_status(struct usb_ep *ep)
 425{
 426        int ret;
 427
 428        if (ep->ops->fifo_status)
 429                ret = ep->ops->fifo_status(ep);
 430        else
 431                ret = -EOPNOTSUPP;
 432
 433        trace_usb_ep_fifo_status(ep, ret);
 434
 435        return ret;
 436}
 437EXPORT_SYMBOL_GPL(usb_ep_fifo_status);
 438
 439/**
 440 * usb_ep_fifo_flush - flushes contents of a fifo
 441 * @ep: the endpoint whose fifo is being flushed.
 442 *
 443 * This call may be used to flush the "unclaimed data" that may exist in
 444 * an endpoint fifo after abnormal transaction terminations.  The call
 445 * must never be used except when endpoint is not being used for any
 446 * protocol translation.
 447 *
 448 * This routine may be called in interrupt context.
 449 */
 450void usb_ep_fifo_flush(struct usb_ep *ep)
 451{
 452        if (ep->ops->fifo_flush)
 453                ep->ops->fifo_flush(ep);
 454
 455        trace_usb_ep_fifo_flush(ep, 0);
 456}
 457EXPORT_SYMBOL_GPL(usb_ep_fifo_flush);
 458
 459/* ------------------------------------------------------------------------- */
 460
 461/**
 462 * usb_gadget_frame_number - returns the current frame number
 463 * @gadget: controller that reports the frame number
 464 *
 465 * Returns the usb frame number, normally eleven bits from a SOF packet,
 466 * or negative errno if this device doesn't support this capability.
 467 */
 468int usb_gadget_frame_number(struct usb_gadget *gadget)
 469{
 470        int ret;
 471
 472        ret = gadget->ops->get_frame(gadget);
 473
 474        trace_usb_gadget_frame_number(gadget, ret);
 475
 476        return ret;
 477}
 478EXPORT_SYMBOL_GPL(usb_gadget_frame_number);
 479
 480/**
 481 * usb_gadget_wakeup - tries to wake up the host connected to this gadget
 482 * @gadget: controller used to wake up the host
 483 *
 484 * Returns zero on success, else negative error code if the hardware
 485 * doesn't support such attempts, or its support has not been enabled
 486 * by the usb host.  Drivers must return device descriptors that report
 487 * their ability to support this, or hosts won't enable it.
 488 *
 489 * This may also try to use SRP to wake the host and start enumeration,
 490 * even if OTG isn't otherwise in use.  OTG devices may also start
 491 * remote wakeup even when hosts don't explicitly enable it.
 492 */
 493int usb_gadget_wakeup(struct usb_gadget *gadget)
 494{
 495        int ret = 0;
 496
 497        if (!gadget->ops->wakeup) {
 498                ret = -EOPNOTSUPP;
 499                goto out;
 500        }
 501
 502        ret = gadget->ops->wakeup(gadget);
 503
 504out:
 505        trace_usb_gadget_wakeup(gadget, ret);
 506
 507        return ret;
 508}
 509EXPORT_SYMBOL_GPL(usb_gadget_wakeup);
 510
 511/**
 512 * usb_gadget_set_selfpowered - sets the device selfpowered feature.
 513 * @gadget:the device being declared as self-powered
 514 *
 515 * this affects the device status reported by the hardware driver
 516 * to reflect that it now has a local power supply.
 517 *
 518 * returns zero on success, else negative errno.
 519 */
 520int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
 521{
 522        int ret = 0;
 523
 524        if (!gadget->ops->set_selfpowered) {
 525                ret = -EOPNOTSUPP;
 526                goto out;
 527        }
 528
 529        ret = gadget->ops->set_selfpowered(gadget, 1);
 530
 531out:
 532        trace_usb_gadget_set_selfpowered(gadget, ret);
 533
 534        return ret;
 535}
 536EXPORT_SYMBOL_GPL(usb_gadget_set_selfpowered);
 537
 538/**
 539 * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
 540 * @gadget:the device being declared as bus-powered
 541 *
 542 * this affects the device status reported by the hardware driver.
 543 * some hardware may not support bus-powered operation, in which
 544 * case this feature's value can never change.
 545 *
 546 * returns zero on success, else negative errno.
 547 */
 548int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
 549{
 550        int ret = 0;
 551
 552        if (!gadget->ops->set_selfpowered) {
 553                ret = -EOPNOTSUPP;
 554                goto out;
 555        }
 556
 557        ret = gadget->ops->set_selfpowered(gadget, 0);
 558
 559out:
 560        trace_usb_gadget_clear_selfpowered(gadget, ret);
 561
 562        return ret;
 563}
 564EXPORT_SYMBOL_GPL(usb_gadget_clear_selfpowered);
 565
 566/**
 567 * usb_gadget_vbus_connect - Notify controller that VBUS is powered
 568 * @gadget:The device which now has VBUS power.
 569 * Context: can sleep
 570 *
 571 * This call is used by a driver for an external transceiver (or GPIO)
 572 * that detects a VBUS power session starting.  Common responses include
 573 * resuming the controller, activating the D+ (or D-) pullup to let the
 574 * host detect that a USB device is attached, and starting to draw power
 575 * (8mA or possibly more, especially after SET_CONFIGURATION).
 576 *
 577 * Returns zero on success, else negative errno.
 578 */
 579int usb_gadget_vbus_connect(struct usb_gadget *gadget)
 580{
 581        int ret = 0;
 582
 583        if (!gadget->ops->vbus_session) {
 584                ret = -EOPNOTSUPP;
 585                goto out;
 586        }
 587
 588        ret = gadget->ops->vbus_session(gadget, 1);
 589
 590out:
 591        trace_usb_gadget_vbus_connect(gadget, ret);
 592
 593        return ret;
 594}
 595EXPORT_SYMBOL_GPL(usb_gadget_vbus_connect);
 596
 597/**
 598 * usb_gadget_vbus_draw - constrain controller's VBUS power usage
 599 * @gadget:The device whose VBUS usage is being described
 600 * @mA:How much current to draw, in milliAmperes.  This should be twice
 601 *      the value listed in the configuration descriptor bMaxPower field.
 602 *
 603 * This call is used by gadget drivers during SET_CONFIGURATION calls,
 604 * reporting how much power the device may consume.  For example, this
 605 * could affect how quickly batteries are recharged.
 606 *
 607 * Returns zero on success, else negative errno.
 608 */
 609int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
 610{
 611        int ret = 0;
 612
 613        if (!gadget->ops->vbus_draw) {
 614                ret = -EOPNOTSUPP;
 615                goto out;
 616        }
 617
 618        ret = gadget->ops->vbus_draw(gadget, mA);
 619        if (!ret)
 620                gadget->mA = mA;
 621
 622out:
 623        trace_usb_gadget_vbus_draw(gadget, ret);
 624
 625        return ret;
 626}
 627EXPORT_SYMBOL_GPL(usb_gadget_vbus_draw);
 628
 629/**
 630 * usb_gadget_vbus_disconnect - notify controller about VBUS session end
 631 * @gadget:the device whose VBUS supply is being described
 632 * Context: can sleep
 633 *
 634 * This call is used by a driver for an external transceiver (or GPIO)
 635 * that detects a VBUS power session ending.  Common responses include
 636 * reversing everything done in usb_gadget_vbus_connect().
 637 *
 638 * Returns zero on success, else negative errno.
 639 */
 640int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
 641{
 642        int ret = 0;
 643
 644        if (!gadget->ops->vbus_session) {
 645                ret = -EOPNOTSUPP;
 646                goto out;
 647        }
 648
 649        ret = gadget->ops->vbus_session(gadget, 0);
 650
 651out:
 652        trace_usb_gadget_vbus_disconnect(gadget, ret);
 653
 654        return ret;
 655}
 656EXPORT_SYMBOL_GPL(usb_gadget_vbus_disconnect);
 657
 658/**
 659 * usb_gadget_connect - software-controlled connect to USB host
 660 * @gadget:the peripheral being connected
 661 *
 662 * Enables the D+ (or potentially D-) pullup.  The host will start
 663 * enumerating this gadget when the pullup is active and a VBUS session
 664 * is active (the link is powered).
 665 *
 666 * Returns zero on success, else negative errno.
 667 */
 668int usb_gadget_connect(struct usb_gadget *gadget)
 669{
 670        int ret = 0;
 671
 672        if (!gadget->ops->pullup) {
 673                ret = -EOPNOTSUPP;
 674                goto out;
 675        }
 676
 677        if (gadget->deactivated) {
 678                /*
 679                 * If gadget is deactivated we only save new state.
 680                 * Gadget will be connected automatically after activation.
 681                 */
 682                gadget->connected = true;
 683                goto out;
 684        }
 685
 686        ret = gadget->ops->pullup(gadget, 1);
 687        if (!ret)
 688                gadget->connected = 1;
 689
 690out:
 691        trace_usb_gadget_connect(gadget, ret);
 692
 693        return ret;
 694}
 695EXPORT_SYMBOL_GPL(usb_gadget_connect);
 696
 697/**
 698 * usb_gadget_disconnect - software-controlled disconnect from USB host
 699 * @gadget:the peripheral being disconnected
 700 *
 701 * Disables the D+ (or potentially D-) pullup, which the host may see
 702 * as a disconnect (when a VBUS session is active).  Not all systems
 703 * support software pullup controls.
 704 *
 705 * Following a successful disconnect, invoke the ->disconnect() callback
 706 * for the current gadget driver so that UDC drivers don't need to.
 707 *
 708 * Returns zero on success, else negative errno.
 709 */
 710int usb_gadget_disconnect(struct usb_gadget *gadget)
 711{
 712        int ret = 0;
 713
 714        if (!gadget->ops->pullup) {
 715                ret = -EOPNOTSUPP;
 716                goto out;
 717        }
 718
 719        if (!gadget->connected)
 720                goto out;
 721
 722        if (gadget->deactivated) {
 723                /*
 724                 * If gadget is deactivated we only save new state.
 725                 * Gadget will stay disconnected after activation.
 726                 */
 727                gadget->connected = false;
 728                goto out;
 729        }
 730
 731        ret = gadget->ops->pullup(gadget, 0);
 732        if (!ret) {
 733                gadget->connected = 0;
 734                gadget->udc->driver->disconnect(gadget);
 735        }
 736
 737out:
 738        trace_usb_gadget_disconnect(gadget, ret);
 739
 740        return ret;
 741}
 742EXPORT_SYMBOL_GPL(usb_gadget_disconnect);
 743
 744/**
 745 * usb_gadget_deactivate - deactivate function which is not ready to work
 746 * @gadget: the peripheral being deactivated
 747 *
 748 * This routine may be used during the gadget driver bind() call to prevent
 749 * the peripheral from ever being visible to the USB host, unless later
 750 * usb_gadget_activate() is called.  For example, user mode components may
 751 * need to be activated before the system can talk to hosts.
 752 *
 753 * Returns zero on success, else negative errno.
 754 */
 755int usb_gadget_deactivate(struct usb_gadget *gadget)
 756{
 757        int ret = 0;
 758
 759        if (gadget->deactivated)
 760                goto out;
 761
 762        if (gadget->connected) {
 763                ret = usb_gadget_disconnect(gadget);
 764                if (ret)
 765                        goto out;
 766
 767                /*
 768                 * If gadget was being connected before deactivation, we want
 769                 * to reconnect it in usb_gadget_activate().
 770                 */
 771                gadget->connected = true;
 772        }
 773        gadget->deactivated = true;
 774
 775out:
 776        trace_usb_gadget_deactivate(gadget, ret);
 777
 778        return ret;
 779}
 780EXPORT_SYMBOL_GPL(usb_gadget_deactivate);
 781
 782/**
 783 * usb_gadget_activate - activate function which is not ready to work
 784 * @gadget: the peripheral being activated
 785 *
 786 * This routine activates gadget which was previously deactivated with
 787 * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed.
 788 *
 789 * Returns zero on success, else negative errno.
 790 */
 791int usb_gadget_activate(struct usb_gadget *gadget)
 792{
 793        int ret = 0;
 794
 795        if (!gadget->deactivated)
 796                goto out;
 797
 798        gadget->deactivated = false;
 799
 800        /*
 801         * If gadget has been connected before deactivation, or became connected
 802         * while it was being deactivated, we call usb_gadget_connect().
 803         */
 804        if (gadget->connected)
 805                ret = usb_gadget_connect(gadget);
 806
 807out:
 808        trace_usb_gadget_activate(gadget, ret);
 809
 810        return ret;
 811}
 812EXPORT_SYMBOL_GPL(usb_gadget_activate);
 813
 814/* ------------------------------------------------------------------------- */
 815
 816#ifdef  CONFIG_HAS_DMA
 817
 818int usb_gadget_map_request_by_dev(struct device *dev,
 819                struct usb_request *req, int is_in)
 820{
 821        if (req->length == 0)
 822                return 0;
 823
 824        if (req->num_sgs) {
 825                int     mapped;
 826
 827                mapped = dma_map_sg(dev, req->sg, req->num_sgs,
 828                                is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 829                if (mapped == 0) {
 830                        dev_err(dev, "failed to map SGs\n");
 831                        return -EFAULT;
 832                }
 833
 834                req->num_mapped_sgs = mapped;
 835        } else {
 836                if (is_vmalloc_addr(req->buf)) {
 837                        dev_err(dev, "buffer is not dma capable\n");
 838                        return -EFAULT;
 839                } else if (object_is_on_stack(req->buf)) {
 840                        dev_err(dev, "buffer is on stack\n");
 841                        return -EFAULT;
 842                }
 843
 844                req->dma = dma_map_single(dev, req->buf, req->length,
 845                                is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 846
 847                if (dma_mapping_error(dev, req->dma)) {
 848                        dev_err(dev, "failed to map buffer\n");
 849                        return -EFAULT;
 850                }
 851
 852                req->dma_mapped = 1;
 853        }
 854
 855        return 0;
 856}
 857EXPORT_SYMBOL_GPL(usb_gadget_map_request_by_dev);
 858
 859int usb_gadget_map_request(struct usb_gadget *gadget,
 860                struct usb_request *req, int is_in)
 861{
 862        return usb_gadget_map_request_by_dev(gadget->dev.parent, req, is_in);
 863}
 864EXPORT_SYMBOL_GPL(usb_gadget_map_request);
 865
 866void usb_gadget_unmap_request_by_dev(struct device *dev,
 867                struct usb_request *req, int is_in)
 868{
 869        if (req->length == 0)
 870                return;
 871
 872        if (req->num_mapped_sgs) {
 873                dma_unmap_sg(dev, req->sg, req->num_sgs,
 874                                is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 875
 876                req->num_mapped_sgs = 0;
 877        } else if (req->dma_mapped) {
 878                dma_unmap_single(dev, req->dma, req->length,
 879                                is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 880                req->dma_mapped = 0;
 881        }
 882}
 883EXPORT_SYMBOL_GPL(usb_gadget_unmap_request_by_dev);
 884
 885void usb_gadget_unmap_request(struct usb_gadget *gadget,
 886                struct usb_request *req, int is_in)
 887{
 888        usb_gadget_unmap_request_by_dev(gadget->dev.parent, req, is_in);
 889}
 890EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);
 891
 892#endif  /* CONFIG_HAS_DMA */
 893
 894/* ------------------------------------------------------------------------- */
 895
 896/**
 897 * usb_gadget_giveback_request - give the request back to the gadget layer
 898 * @ep: the endpoint to be used with with the request
 899 * @req: the request being given back
 900 *
 901 * This is called by device controller drivers in order to return the
 902 * completed request back to the gadget layer.
 903 */
 904void usb_gadget_giveback_request(struct usb_ep *ep,
 905                struct usb_request *req)
 906{
 907        if (likely(req->status == 0))
 908                usb_led_activity(USB_LED_EVENT_GADGET);
 909
 910        trace_usb_gadget_giveback_request(ep, req, 0);
 911
 912        req->complete(ep, req);
 913}
 914EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
 915
 916/* ------------------------------------------------------------------------- */
 917
 918/**
 919 * gadget_find_ep_by_name - returns ep whose name is the same as sting passed
 920 *      in second parameter or NULL if searched endpoint not found
 921 * @g: controller to check for quirk
 922 * @name: name of searched endpoint
 923 */
 924struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g, const char *name)
 925{
 926        struct usb_ep *ep;
 927
 928        gadget_for_each_ep(ep, g) {
 929                if (!strcmp(ep->name, name))
 930                        return ep;
 931        }
 932
 933        return NULL;
 934}
 935EXPORT_SYMBOL_GPL(gadget_find_ep_by_name);
 936
 937/* ------------------------------------------------------------------------- */
 938
 939int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
 940                struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
 941                struct usb_ss_ep_comp_descriptor *ep_comp)
 942{
 943        u8              type;
 944        u16             max;
 945        int             num_req_streams = 0;
 946
 947        /* endpoint already claimed? */
 948        if (ep->claimed)
 949                return 0;
 950
 951        type = usb_endpoint_type(desc);
 952        max = usb_endpoint_maxp(desc);
 953
 954        if (usb_endpoint_dir_in(desc) && !ep->caps.dir_in)
 955                return 0;
 956        if (usb_endpoint_dir_out(desc) && !ep->caps.dir_out)
 957                return 0;
 958
 959        if (max > ep->maxpacket_limit)
 960                return 0;
 961
 962        /* "high bandwidth" works only at high speed */
 963        if (!gadget_is_dualspeed(gadget) && usb_endpoint_maxp_mult(desc) > 1)
 964                return 0;
 965
 966        switch (type) {
 967        case USB_ENDPOINT_XFER_CONTROL:
 968                /* only support ep0 for portable CONTROL traffic */
 969                return 0;
 970        case USB_ENDPOINT_XFER_ISOC:
 971                if (!ep->caps.type_iso)
 972                        return 0;
 973                /* ISO:  limit 1023 bytes full speed, 1024 high/super speed */
 974                if (!gadget_is_dualspeed(gadget) && max > 1023)
 975                        return 0;
 976                break;
 977        case USB_ENDPOINT_XFER_BULK:
 978                if (!ep->caps.type_bulk)
 979                        return 0;
 980                if (ep_comp && gadget_is_superspeed(gadget)) {
 981                        /* Get the number of required streams from the
 982                         * EP companion descriptor and see if the EP
 983                         * matches it
 984                         */
 985                        num_req_streams = ep_comp->bmAttributes & 0x1f;
 986                        if (num_req_streams > ep->max_streams)
 987                                return 0;
 988                }
 989                break;
 990        case USB_ENDPOINT_XFER_INT:
 991                /* Bulk endpoints handle interrupt transfers,
 992                 * except the toggle-quirky iso-synch kind
 993                 */
 994                if (!ep->caps.type_int && !ep->caps.type_bulk)
 995                        return 0;
 996                /* INT:  limit 64 bytes full speed, 1024 high/super speed */
 997                if (!gadget_is_dualspeed(gadget) && max > 64)
 998                        return 0;
 999                break;
1000        }
1001
1002        return 1;
1003}
1004EXPORT_SYMBOL_GPL(usb_gadget_ep_match_desc);
1005
1006/* ------------------------------------------------------------------------- */
1007
1008static void usb_gadget_state_work(struct work_struct *work)
1009{
1010        struct usb_gadget *gadget = work_to_gadget(work);
1011        struct usb_udc *udc = gadget->udc;
1012
1013        if (udc)
1014                sysfs_notify(&udc->dev.kobj, NULL, "state");
1015}
1016
1017void usb_gadget_set_state(struct usb_gadget *gadget,
1018                enum usb_device_state state)
1019{
1020        gadget->state = state;
1021        schedule_work(&gadget->work);
1022}
1023EXPORT_SYMBOL_GPL(usb_gadget_set_state);
1024
1025/* ------------------------------------------------------------------------- */
1026
1027static void usb_udc_connect_control(struct usb_udc *udc)
1028{
1029        if (udc->vbus)
1030                usb_gadget_connect(udc->gadget);
1031        else
1032                usb_gadget_disconnect(udc->gadget);
1033}
1034
1035/**
1036 * usb_udc_vbus_handler - updates the udc core vbus status, and try to
1037 * connect or disconnect gadget
1038 * @gadget: The gadget which vbus change occurs
1039 * @status: The vbus status
1040 *
1041 * The udc driver calls it when it wants to connect or disconnect gadget
1042 * according to vbus status.
1043 */
1044void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status)
1045{
1046        struct usb_udc *udc = gadget->udc;
1047
1048        if (udc) {
1049                udc->vbus = status;
1050                usb_udc_connect_control(udc);
1051        }
1052}
1053EXPORT_SYMBOL_GPL(usb_udc_vbus_handler);
1054
1055/**
1056 * usb_gadget_udc_reset - notifies the udc core that bus reset occurs
1057 * @gadget: The gadget which bus reset occurs
1058 * @driver: The gadget driver we want to notify
1059 *
1060 * If the udc driver has bus reset handler, it needs to call this when the bus
1061 * reset occurs, it notifies the gadget driver that the bus reset occurs as
1062 * well as updates gadget state.
1063 */
1064void usb_gadget_udc_reset(struct usb_gadget *gadget,
1065                struct usb_gadget_driver *driver)
1066{
1067        driver->reset(gadget);
1068        usb_gadget_set_state(gadget, USB_STATE_DEFAULT);
1069}
1070EXPORT_SYMBOL_GPL(usb_gadget_udc_reset);
1071
1072/**
1073 * usb_gadget_udc_start - tells usb device controller to start up
1074 * @udc: The UDC to be started
1075 *
1076 * This call is issued by the UDC Class driver when it's about
1077 * to register a gadget driver to the device controller, before
1078 * calling gadget driver's bind() method.
1079 *
1080 * It allows the controller to be powered off until strictly
1081 * necessary to have it powered on.
1082 *
1083 * Returns zero on success, else negative errno.
1084 */
1085static inline int usb_gadget_udc_start(struct usb_udc *udc)
1086{
1087        int ret;
1088
1089        if (udc->started) {
1090                dev_err(&udc->dev, "UDC had already started\n");
1091                return -EBUSY;
1092        }
1093
1094        ret = udc->gadget->ops->udc_start(udc->gadget, udc->driver);
1095        if (!ret)
1096                udc->started = true;
1097
1098        return ret;
1099}
1100
1101/**
1102 * usb_gadget_udc_stop - tells usb device controller we don't need it anymore
1103 * @udc: The UDC to be stopped
1104 *
1105 * This call is issued by the UDC Class driver after calling
1106 * gadget driver's unbind() method.
1107 *
1108 * The details are implementation specific, but it can go as
1109 * far as powering off UDC completely and disable its data
1110 * line pullups.
1111 */
1112static inline void usb_gadget_udc_stop(struct usb_udc *udc)
1113{
1114        if (!udc->started) {
1115                dev_err(&udc->dev, "UDC had already stopped\n");
1116                return;
1117        }
1118
1119        udc->gadget->ops->udc_stop(udc->gadget);
1120        udc->started = false;
1121}
1122
1123/**
1124 * usb_gadget_udc_set_speed - tells usb device controller speed supported by
1125 *    current driver
1126 * @udc: The device we want to set maximum speed
1127 * @speed: The maximum speed to allowed to run
1128 *
1129 * This call is issued by the UDC Class driver before calling
1130 * usb_gadget_udc_start() in order to make sure that we don't try to
1131 * connect on speeds the gadget driver doesn't support.
1132 */
1133static inline void usb_gadget_udc_set_speed(struct usb_udc *udc,
1134                                            enum usb_device_speed speed)
1135{
1136        struct usb_gadget *gadget = udc->gadget;
1137        enum usb_device_speed s;
1138
1139        if (speed == USB_SPEED_UNKNOWN)
1140                s = gadget->max_speed;
1141        else
1142                s = min(speed, gadget->max_speed);
1143
1144        if (s == USB_SPEED_SUPER_PLUS && gadget->ops->udc_set_ssp_rate)
1145                gadget->ops->udc_set_ssp_rate(gadget, gadget->max_ssp_rate);
1146        else if (gadget->ops->udc_set_speed)
1147                gadget->ops->udc_set_speed(gadget, s);
1148}
1149
1150/**
1151 * usb_gadget_enable_async_callbacks - tell usb device controller to enable asynchronous callbacks
1152 * @udc: The UDC which should enable async callbacks
1153 *
1154 * This routine is used when binding gadget drivers.  It undoes the effect
1155 * of usb_gadget_disable_async_callbacks(); the UDC driver should enable IRQs
1156 * (if necessary) and resume issuing callbacks.
1157 *
1158 * This routine will always be called in process context.
1159 */
1160static inline void usb_gadget_enable_async_callbacks(struct usb_udc *udc)
1161{
1162        struct usb_gadget *gadget = udc->gadget;
1163
1164        if (gadget->ops->udc_async_callbacks)
1165                gadget->ops->udc_async_callbacks(gadget, true);
1166}
1167
1168/**
1169 * usb_gadget_disable_async_callbacks - tell usb device controller to disable asynchronous callbacks
1170 * @udc: The UDC which should disable async callbacks
1171 *
1172 * This routine is used when unbinding gadget drivers.  It prevents a race:
1173 * The UDC driver doesn't know when the gadget driver's ->unbind callback
1174 * runs, so unless it is told to disable asynchronous callbacks, it might
1175 * issue a callback (such as ->disconnect) after the unbind has completed.
1176 *
1177 * After this function runs, the UDC driver must suppress all ->suspend,
1178 * ->resume, ->disconnect, ->reset, and ->setup callbacks to the gadget driver
1179 * until async callbacks are again enabled.  A simple-minded but effective
1180 * way to accomplish this is to tell the UDC hardware not to generate any
1181 * more IRQs.
1182 *
1183 * Request completion callbacks must still be issued.  However, it's okay
1184 * to defer them until the request is cancelled, since the pull-up will be
1185 * turned off during the time period when async callbacks are disabled.
1186 *
1187 * This routine will always be called in process context.
1188 */
1189static inline void usb_gadget_disable_async_callbacks(struct usb_udc *udc)
1190{
1191        struct usb_gadget *gadget = udc->gadget;
1192
1193        if (gadget->ops->udc_async_callbacks)
1194                gadget->ops->udc_async_callbacks(gadget, false);
1195}
1196
1197/**
1198 * usb_udc_release - release the usb_udc struct
1199 * @dev: the dev member within usb_udc
1200 *
1201 * This is called by driver's core in order to free memory once the last
1202 * reference is released.
1203 */
1204static void usb_udc_release(struct device *dev)
1205{
1206        struct usb_udc *udc;
1207
1208        udc = container_of(dev, struct usb_udc, dev);
1209        dev_dbg(dev, "releasing '%s'\n", dev_name(dev));
1210        kfree(udc);
1211}
1212
1213static const struct attribute_group *usb_udc_attr_groups[];
1214
1215static void usb_udc_nop_release(struct device *dev)
1216{
1217        dev_vdbg(dev, "%s\n", __func__);
1218}
1219
1220/* should be called with udc_lock held */
1221static int check_pending_gadget_drivers(struct usb_udc *udc)
1222{
1223        struct usb_gadget_driver *driver;
1224        int ret = 0;
1225
1226        list_for_each_entry(driver, &gadget_driver_pending_list, pending)
1227                if (!driver->udc_name || strcmp(driver->udc_name,
1228                                                dev_name(&udc->dev)) == 0) {
1229                        ret = udc_bind_to_driver(udc, driver);
1230                        if (ret != -EPROBE_DEFER)
1231                                list_del_init(&driver->pending);
1232                        break;
1233                }
1234
1235        return ret;
1236}
1237
1238/**
1239 * usb_initialize_gadget - initialize a gadget and its embedded struct device
1240 * @parent: the parent device to this udc. Usually the controller driver's
1241 * device.
1242 * @gadget: the gadget to be initialized.
1243 * @release: a gadget release function.
1244 *
1245 * Returns zero on success, negative errno otherwise.
1246 * Calls the gadget release function in the latter case.
1247 */
1248void usb_initialize_gadget(struct device *parent, struct usb_gadget *gadget,
1249                void (*release)(struct device *dev))
1250{
1251        dev_set_name(&gadget->dev, "gadget");
1252        INIT_WORK(&gadget->work, usb_gadget_state_work);
1253        gadget->dev.parent = parent;
1254
1255        if (release)
1256                gadget->dev.release = release;
1257        else
1258                gadget->dev.release = usb_udc_nop_release;
1259
1260        device_initialize(&gadget->dev);
1261}
1262EXPORT_SYMBOL_GPL(usb_initialize_gadget);
1263
1264/**
1265 * usb_add_gadget - adds a new gadget to the udc class driver list
1266 * @gadget: the gadget to be added to the list.
1267 *
1268 * Returns zero on success, negative errno otherwise.
1269 * Does not do a final usb_put_gadget() if an error occurs.
1270 */
1271int usb_add_gadget(struct usb_gadget *gadget)
1272{
1273        struct usb_udc          *udc;
1274        int                     ret = -ENOMEM;
1275
1276        udc = kzalloc(sizeof(*udc), GFP_KERNEL);
1277        if (!udc)
1278                goto error;
1279
1280        device_initialize(&udc->dev);
1281        udc->dev.release = usb_udc_release;
1282        udc->dev.class = udc_class;
1283        udc->dev.groups = usb_udc_attr_groups;
1284        udc->dev.parent = gadget->dev.parent;
1285        ret = dev_set_name(&udc->dev, "%s",
1286                        kobject_name(&gadget->dev.parent->kobj));
1287        if (ret)
1288                goto err_put_udc;
1289
1290        ret = device_add(&gadget->dev);
1291        if (ret)
1292                goto err_put_udc;
1293
1294        udc->gadget = gadget;
1295        gadget->udc = udc;
1296
1297        udc->started = false;
1298
1299        mutex_lock(&udc_lock);
1300        list_add_tail(&udc->list, &udc_list);
1301
1302        ret = device_add(&udc->dev);
1303        if (ret)
1304                goto err_unlist_udc;
1305
1306        usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
1307        udc->vbus = true;
1308
1309        /* pick up one of pending gadget drivers */
1310        ret = check_pending_gadget_drivers(udc);
1311        if (ret)
1312                goto err_del_udc;
1313
1314        mutex_unlock(&udc_lock);
1315
1316        return 0;
1317
1318 err_del_udc:
1319        flush_work(&gadget->work);
1320        device_del(&udc->dev);
1321
1322 err_unlist_udc:
1323        list_del(&udc->list);
1324        mutex_unlock(&udc_lock);
1325
1326        device_del(&gadget->dev);
1327
1328 err_put_udc:
1329        put_device(&udc->dev);
1330
1331 error:
1332        return ret;
1333}
1334EXPORT_SYMBOL_GPL(usb_add_gadget);
1335
1336/**
1337 * usb_add_gadget_udc_release - adds a new gadget to the udc class driver list
1338 * @parent: the parent device to this udc. Usually the controller driver's
1339 * device.
1340 * @gadget: the gadget to be added to the list.
1341 * @release: a gadget release function.
1342 *
1343 * Returns zero on success, negative errno otherwise.
1344 * Calls the gadget release function in the latter case.
1345 */
1346int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
1347                void (*release)(struct device *dev))
1348{
1349        int     ret;
1350
1351        usb_initialize_gadget(parent, gadget, release);
1352        ret = usb_add_gadget(gadget);
1353        if (ret)
1354                usb_put_gadget(gadget);
1355        return ret;
1356}
1357EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release);
1358
1359/**
1360 * usb_get_gadget_udc_name - get the name of the first UDC controller
1361 * This functions returns the name of the first UDC controller in the system.
1362 * Please note that this interface is usefull only for legacy drivers which
1363 * assume that there is only one UDC controller in the system and they need to
1364 * get its name before initialization. There is no guarantee that the UDC
1365 * of the returned name will be still available, when gadget driver registers
1366 * itself.
1367 *
1368 * Returns pointer to string with UDC controller name on success, NULL
1369 * otherwise. Caller should kfree() returned string.
1370 */
1371char *usb_get_gadget_udc_name(void)
1372{
1373        struct usb_udc *udc;
1374        char *name = NULL;
1375
1376        /* For now we take the first available UDC */
1377        mutex_lock(&udc_lock);
1378        list_for_each_entry(udc, &udc_list, list) {
1379                if (!udc->driver) {
1380                        name = kstrdup(udc->gadget->name, GFP_KERNEL);
1381                        break;
1382                }
1383        }
1384        mutex_unlock(&udc_lock);
1385        return name;
1386}
1387EXPORT_SYMBOL_GPL(usb_get_gadget_udc_name);
1388
1389/**
1390 * usb_add_gadget_udc - adds a new gadget to the udc class driver list
1391 * @parent: the parent device to this udc. Usually the controller
1392 * driver's device.
1393 * @gadget: the gadget to be added to the list
1394 *
1395 * Returns zero on success, negative errno otherwise.
1396 */
1397int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
1398{
1399        return usb_add_gadget_udc_release(parent, gadget, NULL);
1400}
1401EXPORT_SYMBOL_GPL(usb_add_gadget_udc);
1402
1403static void usb_gadget_remove_driver(struct usb_udc *udc)
1404{
1405        dev_dbg(&udc->dev, "unregistering UDC driver [%s]\n",
1406                        udc->driver->function);
1407
1408        kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
1409
1410        usb_gadget_disconnect(udc->gadget);
1411        usb_gadget_disable_async_callbacks(udc);
1412        if (udc->gadget->irq)
1413                synchronize_irq(udc->gadget->irq);
1414        udc->driver->unbind(udc->gadget);
1415        usb_gadget_udc_stop(udc);
1416
1417        udc->driver = NULL;
1418        udc->dev.driver = NULL;
1419        udc->gadget->dev.driver = NULL;
1420}
1421
1422/**
1423 * usb_del_gadget - deletes @udc from udc_list
1424 * @gadget: the gadget to be removed.
1425 *
1426 * This will call usb_gadget_unregister_driver() if
1427 * the @udc is still busy.
1428 * It will not do a final usb_put_gadget().
1429 */
1430void usb_del_gadget(struct usb_gadget *gadget)
1431{
1432        struct usb_udc *udc = gadget->udc;
1433
1434        if (!udc)
1435                return;
1436
1437        dev_vdbg(gadget->dev.parent, "unregistering gadget\n");
1438
1439        mutex_lock(&udc_lock);
1440        list_del(&udc->list);
1441
1442        if (udc->driver) {
1443                struct usb_gadget_driver *driver = udc->driver;
1444
1445                usb_gadget_remove_driver(udc);
1446                list_add(&driver->pending, &gadget_driver_pending_list);
1447        }
1448        mutex_unlock(&udc_lock);
1449
1450        kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
1451        flush_work(&gadget->work);
1452        device_unregister(&udc->dev);
1453        device_del(&gadget->dev);
1454}
1455EXPORT_SYMBOL_GPL(usb_del_gadget);
1456
1457/**
1458 * usb_del_gadget_udc - deletes @udc from udc_list
1459 * @gadget: the gadget to be removed.
1460 *
1461 * Calls usb_del_gadget() and does a final usb_put_gadget().
1462 */
1463void usb_del_gadget_udc(struct usb_gadget *gadget)
1464{
1465        usb_del_gadget(gadget);
1466        usb_put_gadget(gadget);
1467}
1468EXPORT_SYMBOL_GPL(usb_del_gadget_udc);
1469
1470/* ------------------------------------------------------------------------- */
1471
1472static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *driver)
1473{
1474        int ret;
1475
1476        dev_dbg(&udc->dev, "registering UDC driver [%s]\n",
1477                        driver->function);
1478
1479        udc->driver = driver;
1480        udc->dev.driver = &driver->driver;
1481        udc->gadget->dev.driver = &driver->driver;
1482
1483        usb_gadget_udc_set_speed(udc, driver->max_speed);
1484
1485        ret = driver->bind(udc->gadget, driver);
1486        if (ret)
1487                goto err1;
1488        ret = usb_gadget_udc_start(udc);
1489        if (ret) {
1490                driver->unbind(udc->gadget);
1491                goto err1;
1492        }
1493        usb_gadget_enable_async_callbacks(udc);
1494        usb_udc_connect_control(udc);
1495
1496        kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
1497        return 0;
1498err1:
1499        if (ret != -EISNAM)
1500                dev_err(&udc->dev, "failed to start %s: %d\n",
1501                        udc->driver->function, ret);
1502        udc->driver = NULL;
1503        udc->dev.driver = NULL;
1504        udc->gadget->dev.driver = NULL;
1505        return ret;
1506}
1507
1508int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
1509{
1510        struct usb_udc          *udc = NULL;
1511        int                     ret = -ENODEV;
1512
1513        if (!driver || !driver->bind || !driver->setup)
1514                return -EINVAL;
1515
1516        mutex_lock(&udc_lock);
1517        if (driver->udc_name) {
1518                list_for_each_entry(udc, &udc_list, list) {
1519                        ret = strcmp(driver->udc_name, dev_name(&udc->dev));
1520                        if (!ret)
1521                                break;
1522                }
1523                if (ret)
1524                        ret = -ENODEV;
1525                else if (udc->driver)
1526                        ret = -EBUSY;
1527                else
1528                        goto found;
1529        } else {
1530                list_for_each_entry(udc, &udc_list, list) {
1531                        /* For now we take the first one */
1532                        if (!udc->driver)
1533                                goto found;
1534                }
1535        }
1536
1537        if (!driver->match_existing_only) {
1538                list_add_tail(&driver->pending, &gadget_driver_pending_list);
1539                pr_info("udc-core: couldn't find an available UDC - added [%s] to list of pending drivers\n",
1540                        driver->function);
1541                ret = 0;
1542        }
1543
1544        mutex_unlock(&udc_lock);
1545        if (ret)
1546                pr_warn("udc-core: couldn't find an available UDC or it's busy\n");
1547        return ret;
1548found:
1549        ret = udc_bind_to_driver(udc, driver);
1550        mutex_unlock(&udc_lock);
1551        return ret;
1552}
1553EXPORT_SYMBOL_GPL(usb_gadget_probe_driver);
1554
1555int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
1556{
1557        struct usb_udc          *udc = NULL;
1558        int                     ret = -ENODEV;
1559
1560        if (!driver || !driver->unbind)
1561                return -EINVAL;
1562
1563        mutex_lock(&udc_lock);
1564        list_for_each_entry(udc, &udc_list, list) {
1565                if (udc->driver == driver) {
1566                        usb_gadget_remove_driver(udc);
1567                        usb_gadget_set_state(udc->gadget,
1568                                             USB_STATE_NOTATTACHED);
1569
1570                        /* Maybe there is someone waiting for this UDC? */
1571                        check_pending_gadget_drivers(udc);
1572                        /*
1573                         * For now we ignore bind errors as probably it's
1574                         * not a valid reason to fail other's gadget unbind
1575                         */
1576                        ret = 0;
1577                        break;
1578                }
1579        }
1580
1581        if (ret) {
1582                list_del(&driver->pending);
1583                ret = 0;
1584        }
1585        mutex_unlock(&udc_lock);
1586        return ret;
1587}
1588EXPORT_SYMBOL_GPL(usb_gadget_unregister_driver);
1589
1590/* ------------------------------------------------------------------------- */
1591
1592static ssize_t srp_store(struct device *dev,
1593                struct device_attribute *attr, const char *buf, size_t n)
1594{
1595        struct usb_udc          *udc = container_of(dev, struct usb_udc, dev);
1596
1597        if (sysfs_streq(buf, "1"))
1598                usb_gadget_wakeup(udc->gadget);
1599
1600        return n;
1601}
1602static DEVICE_ATTR_WO(srp);
1603
1604static ssize_t soft_connect_store(struct device *dev,
1605                struct device_attribute *attr, const char *buf, size_t n)
1606{
1607        struct usb_udc          *udc = container_of(dev, struct usb_udc, dev);
1608        ssize_t                 ret;
1609
1610        mutex_lock(&udc_lock);
1611        if (!udc->driver) {
1612                dev_err(dev, "soft-connect without a gadget driver\n");
1613                ret = -EOPNOTSUPP;
1614                goto out;
1615        }
1616
1617        if (sysfs_streq(buf, "connect")) {
1618                usb_gadget_udc_start(udc);
1619                usb_gadget_connect(udc->gadget);
1620        } else if (sysfs_streq(buf, "disconnect")) {
1621                usb_gadget_disconnect(udc->gadget);
1622                usb_gadget_udc_stop(udc);
1623        } else {
1624                dev_err(dev, "unsupported command '%s'\n", buf);
1625                ret = -EINVAL;
1626                goto out;
1627        }
1628
1629        ret = n;
1630out:
1631        mutex_unlock(&udc_lock);
1632        return ret;
1633}
1634static DEVICE_ATTR_WO(soft_connect);
1635
1636static ssize_t state_show(struct device *dev, struct device_attribute *attr,
1637                          char *buf)
1638{
1639        struct usb_udc          *udc = container_of(dev, struct usb_udc, dev);
1640        struct usb_gadget       *gadget = udc->gadget;
1641
1642        return sprintf(buf, "%s\n", usb_state_string(gadget->state));
1643}
1644static DEVICE_ATTR_RO(state);
1645
1646static ssize_t function_show(struct device *dev, struct device_attribute *attr,
1647                             char *buf)
1648{
1649        struct usb_udc          *udc = container_of(dev, struct usb_udc, dev);
1650        struct usb_gadget_driver *drv = udc->driver;
1651
1652        if (!drv || !drv->function)
1653                return 0;
1654        return scnprintf(buf, PAGE_SIZE, "%s\n", drv->function);
1655}
1656static DEVICE_ATTR_RO(function);
1657
1658#define USB_UDC_SPEED_ATTR(name, param)                                 \
1659ssize_t name##_show(struct device *dev,                                 \
1660                struct device_attribute *attr, char *buf)               \
1661{                                                                       \
1662        struct usb_udc *udc = container_of(dev, struct usb_udc, dev);   \
1663        return scnprintf(buf, PAGE_SIZE, "%s\n",                        \
1664                        usb_speed_string(udc->gadget->param));          \
1665}                                                                       \
1666static DEVICE_ATTR_RO(name)
1667
1668static USB_UDC_SPEED_ATTR(current_speed, speed);
1669static USB_UDC_SPEED_ATTR(maximum_speed, max_speed);
1670
1671#define USB_UDC_ATTR(name)                                      \
1672ssize_t name##_show(struct device *dev,                         \
1673                struct device_attribute *attr, char *buf)       \
1674{                                                               \
1675        struct usb_udc          *udc = container_of(dev, struct usb_udc, dev); \
1676        struct usb_gadget       *gadget = udc->gadget;          \
1677                                                                \
1678        return scnprintf(buf, PAGE_SIZE, "%d\n", gadget->name); \
1679}                                                               \
1680static DEVICE_ATTR_RO(name)
1681
1682static USB_UDC_ATTR(is_otg);
1683static USB_UDC_ATTR(is_a_peripheral);
1684static USB_UDC_ATTR(b_hnp_enable);
1685static USB_UDC_ATTR(a_hnp_support);
1686static USB_UDC_ATTR(a_alt_hnp_support);
1687static USB_UDC_ATTR(is_selfpowered);
1688
1689static struct attribute *usb_udc_attrs[] = {
1690        &dev_attr_srp.attr,
1691        &dev_attr_soft_connect.attr,
1692        &dev_attr_state.attr,
1693        &dev_attr_function.attr,
1694        &dev_attr_current_speed.attr,
1695        &dev_attr_maximum_speed.attr,
1696
1697        &dev_attr_is_otg.attr,
1698        &dev_attr_is_a_peripheral.attr,
1699        &dev_attr_b_hnp_enable.attr,
1700        &dev_attr_a_hnp_support.attr,
1701        &dev_attr_a_alt_hnp_support.attr,
1702        &dev_attr_is_selfpowered.attr,
1703        NULL,
1704};
1705
1706static const struct attribute_group usb_udc_attr_group = {
1707        .attrs = usb_udc_attrs,
1708};
1709
1710static const struct attribute_group *usb_udc_attr_groups[] = {
1711        &usb_udc_attr_group,
1712        NULL,
1713};
1714
1715static int usb_udc_uevent(struct device *dev, struct kobj_uevent_env *env)
1716{
1717        struct usb_udc          *udc = container_of(dev, struct usb_udc, dev);
1718        int                     ret;
1719
1720        ret = add_uevent_var(env, "USB_UDC_NAME=%s", udc->gadget->name);
1721        if (ret) {
1722                dev_err(dev, "failed to add uevent USB_UDC_NAME\n");
1723                return ret;
1724        }
1725
1726        if (udc->driver) {
1727                ret = add_uevent_var(env, "USB_UDC_DRIVER=%s",
1728                                udc->driver->function);
1729                if (ret) {
1730                        dev_err(dev, "failed to add uevent USB_UDC_DRIVER\n");
1731                        return ret;
1732                }
1733        }
1734
1735        return 0;
1736}
1737
1738static int __init usb_udc_init(void)
1739{
1740        udc_class = class_create(THIS_MODULE, "udc");
1741        if (IS_ERR(udc_class)) {
1742                pr_err("failed to create udc class --> %ld\n",
1743                                PTR_ERR(udc_class));
1744                return PTR_ERR(udc_class);
1745        }
1746
1747        udc_class->dev_uevent = usb_udc_uevent;
1748        return 0;
1749}
1750subsys_initcall(usb_udc_init);
1751
1752static void __exit usb_udc_exit(void)
1753{
1754        class_destroy(udc_class);
1755}
1756module_exit(usb_udc_exit);
1757
1758MODULE_DESCRIPTION("UDC Framework");
1759MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
1760MODULE_LICENSE("GPL v2");
1761