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#define pr_fmt(fmt)	"UDC core: " fmt
  10
  11#include <linux/kernel.h>
  12#include <linux/module.h>
  13#include <linux/device.h>
  14#include <linux/list.h>
  15#include <linux/idr.h>
  16#include <linux/err.h>
  17#include <linux/dma-mapping.h>
  18#include <linux/sched/task_stack.h>
  19#include <linux/workqueue.h>
  20
  21#include <linux/usb/ch9.h>
  22#include <linux/usb/gadget.h>
  23#include <linux/usb.h>
  24
  25#include "trace.h"
  26
  27static DEFINE_IDA(gadget_id_numbers);
  28
  29static const struct bus_type gadget_bus_type;
  30
  31/**
  32 * struct usb_udc - describes one usb device controller
  33 * @driver: the gadget driver pointer. For use by the class code
  34 * @dev: the child device to the actual controller
  35 * @gadget: the gadget. For use by the class code
  36 * @list: for use by the udc class driver
  37 * @vbus: for udcs who care about vbus status, this value is real vbus status;
  38 * for udcs who do not care about vbus status, this value is always true
  39 * @started: the UDC's started state. True if the UDC had started.
  40 * @allow_connect: Indicates whether UDC is allowed to be pulled up.
  41 * Set/cleared by gadget_(un)bind_driver() after gadget driver is bound or
  42 * unbound.
  43 * @vbus_work: work routine to handle VBUS status change notifications.
  44 * @connect_lock: protects udc->started, gadget->connect,
  45 * gadget->allow_connect and gadget->deactivate. The routines
  46 * usb_gadget_connect_locked(), usb_gadget_disconnect_locked(),
  47 * usb_udc_connect_control_locked(), usb_gadget_udc_start_locked() and
  48 * usb_gadget_udc_stop_locked() are called with this lock held.
  49 *
  50 * This represents the internal data structure which is used by the UDC-class
  51 * to hold information about udc driver and gadget together.
  52 */
  53struct usb_udc {
  54	struct usb_gadget_driver	*driver;
  55	struct usb_gadget		*gadget;
  56	struct device			dev;
  57	struct list_head		list;
  58	bool				vbus;
  59	bool				started;
  60	bool				allow_connect;
  61	struct work_struct		vbus_work;
  62	struct mutex			connect_lock;
  63};
  64
  65static const struct class udc_class;
  66static LIST_HEAD(udc_list);
  67
  68/* Protects udc_list, udc->driver, driver->is_bound, and related calls */
  69static DEFINE_MUTEX(udc_lock);
  70
  71/* ------------------------------------------------------------------------- */
  72
  73/**
  74 * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
  75 * @ep:the endpoint being configured
  76 * @maxpacket_limit:value of maximum packet size limit
  77 *
  78 * This function should be used only in UDC drivers to initialize endpoint
  79 * (usually in probe function).
  80 */
  81void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
  82					      unsigned maxpacket_limit)
  83{
  84	ep->maxpacket_limit = maxpacket_limit;
  85	ep->maxpacket = maxpacket_limit;
  86
  87	trace_usb_ep_set_maxpacket_limit(ep, 0);
  88}
  89EXPORT_SYMBOL_GPL(usb_ep_set_maxpacket_limit);
  90
  91/**
  92 * usb_ep_enable - configure endpoint, making it usable
  93 * @ep:the endpoint being configured.  may not be the endpoint named "ep0".
  94 *	drivers discover endpoints through the ep_list of a usb_gadget.
  95 *
  96 * When configurations are set, or when interface settings change, the driver
  97 * will enable or disable the relevant endpoints.  while it is enabled, an
  98 * endpoint may be used for i/o until the driver receives a disconnect() from
  99 * the host or until the endpoint is disabled.
 100 *
 101 * the ep0 implementation (which calls this routine) must ensure that the
 102 * hardware capabilities of each endpoint match the descriptor provided
 103 * for it.  for example, an endpoint named "ep2in-bulk" would be usable
 104 * for interrupt transfers as well as bulk, but it likely couldn't be used
 105 * for iso transfers or for endpoint 14.  some endpoints are fully
 106 * configurable, with more generic names like "ep-a".  (remember that for
 107 * USB, "in" means "towards the USB host".)
 108 *
 109 * This routine may be called in an atomic (interrupt) context.
 110 *
 111 * returns zero, or a negative error code.
 112 */
 113int usb_ep_enable(struct usb_ep *ep)
 114{
 115	int ret = 0;
 116
 117	if (ep->enabled)
 118		goto out;
 119
 120	/* UDC drivers can't handle endpoints with maxpacket size 0 */
 121	if (usb_endpoint_maxp(ep->desc) == 0) {
 122		/*
 123		 * We should log an error message here, but we can't call
 124		 * dev_err() because there's no way to find the gadget
 125		 * given only ep.
 126		 */
 127		ret = -EINVAL;
 128		goto out;
 129	}
 130
 131	ret = ep->ops->enable(ep, ep->desc);
 132	if (ret)
 133		goto out;
 134
 135	ep->enabled = true;
 136
 137out:
 138	trace_usb_ep_enable(ep, ret);
 139
 140	return ret;
 141}
 142EXPORT_SYMBOL_GPL(usb_ep_enable);
 143
 144/**
 145 * usb_ep_disable - endpoint is no longer usable
 146 * @ep:the endpoint being unconfigured.  may not be the endpoint named "ep0".
 147 *
 148 * no other task may be using this endpoint when this is called.
 149 * any pending and uncompleted requests will complete with status
 150 * indicating disconnect (-ESHUTDOWN) before this call returns.
 151 * gadget drivers must call usb_ep_enable() again before queueing
 152 * requests to the endpoint.
 153 *
 154 * This routine may be called in an atomic (interrupt) context.
 155 *
 156 * returns zero, or a negative error code.
 157 */
 158int usb_ep_disable(struct usb_ep *ep)
 159{
 160	int ret = 0;
 161
 162	if (!ep->enabled)
 163		goto out;
 164
 165	ret = ep->ops->disable(ep);
 166	if (ret)
 167		goto out;
 168
 169	ep->enabled = false;
 170
 171out:
 172	trace_usb_ep_disable(ep, ret);
 173
 174	return ret;
 175}
 176EXPORT_SYMBOL_GPL(usb_ep_disable);
 177
 178/**
 179 * usb_ep_alloc_request - allocate a request object to use with this endpoint
 180 * @ep:the endpoint to be used with with the request
 181 * @gfp_flags:GFP_* flags to use
 182 *
 183 * Request objects must be allocated with this call, since they normally
 184 * need controller-specific setup and may even need endpoint-specific
 185 * resources such as allocation of DMA descriptors.
 186 * Requests may be submitted with usb_ep_queue(), and receive a single
 187 * completion callback.  Free requests with usb_ep_free_request(), when
 188 * they are no longer needed.
 189 *
 190 * Returns the request, or null if one could not be allocated.
 191 */
 192struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
 193						       gfp_t gfp_flags)
 194{
 195	struct usb_request *req = NULL;
 196
 197	req = ep->ops->alloc_request(ep, gfp_flags);
 198
 199	trace_usb_ep_alloc_request(ep, req, req ? 0 : -ENOMEM);
 200
 201	return req;
 202}
 203EXPORT_SYMBOL_GPL(usb_ep_alloc_request);
 204
 205/**
 206 * usb_ep_free_request - frees a request object
 207 * @ep:the endpoint associated with the request
 208 * @req:the request being freed
 209 *
 210 * Reverses the effect of usb_ep_alloc_request().
 211 * Caller guarantees the request is not queued, and that it will
 212 * no longer be requeued (or otherwise used).
 213 */
 214void usb_ep_free_request(struct usb_ep *ep,
 215				       struct usb_request *req)
 216{
 217	trace_usb_ep_free_request(ep, req, 0);
 218	ep->ops->free_request(ep, req);
 219}
 220EXPORT_SYMBOL_GPL(usb_ep_free_request);
 221
 222/**
 223 * usb_ep_queue - queues (submits) an I/O request to an endpoint.
 224 * @ep:the endpoint associated with the request
 225 * @req:the request being submitted
 226 * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
 227 *	pre-allocate all necessary memory with the request.
 228 *
 229 * This tells the device controller to perform the specified request through
 230 * that endpoint (reading or writing a buffer).  When the request completes,
 231 * including being canceled by usb_ep_dequeue(), the request's completion
 232 * routine is called to return the request to the driver.  Any endpoint
 233 * (except control endpoints like ep0) may have more than one transfer
 234 * request queued; they complete in FIFO order.  Once a gadget driver
 235 * submits a request, that request may not be examined or modified until it
 236 * is given back to that driver through the completion callback.
 237 *
 238 * Each request is turned into one or more packets.  The controller driver
 239 * never merges adjacent requests into the same packet.  OUT transfers
 240 * will sometimes use data that's already buffered in the hardware.
 241 * Drivers can rely on the fact that the first byte of the request's buffer
 242 * always corresponds to the first byte of some USB packet, for both
 243 * IN and OUT transfers.
 244 *
 245 * Bulk endpoints can queue any amount of data; the transfer is packetized
 246 * automatically.  The last packet will be short if the request doesn't fill it
 247 * out completely.  Zero length packets (ZLPs) should be avoided in portable
 248 * protocols since not all usb hardware can successfully handle zero length
 249 * packets.  (ZLPs may be explicitly written, and may be implicitly written if
 250 * the request 'zero' flag is set.)  Bulk endpoints may also be used
 251 * for interrupt transfers; but the reverse is not true, and some endpoints
 252 * won't support every interrupt transfer.  (Such as 768 byte packets.)
 253 *
 254 * Interrupt-only endpoints are less functional than bulk endpoints, for
 255 * example by not supporting queueing or not handling buffers that are
 256 * larger than the endpoint's maxpacket size.  They may also treat data
 257 * toggle differently.
 258 *
 259 * Control endpoints ... after getting a setup() callback, the driver queues
 260 * one response (even if it would be zero length).  That enables the
 261 * status ack, after transferring data as specified in the response.  Setup
 262 * functions may return negative error codes to generate protocol stalls.
 263 * (Note that some USB device controllers disallow protocol stall responses
 264 * in some cases.)  When control responses are deferred (the response is
 265 * written after the setup callback returns), then usb_ep_set_halt() may be
 266 * used on ep0 to trigger protocol stalls.  Depending on the controller,
 267 * it may not be possible to trigger a status-stage protocol stall when the
 268 * data stage is over, that is, from within the response's completion
 269 * routine.
 270 *
 271 * For periodic endpoints, like interrupt or isochronous ones, the usb host
 272 * arranges to poll once per interval, and the gadget driver usually will
 273 * have queued some data to transfer at that time.
 274 *
 275 * Note that @req's ->complete() callback must never be called from
 276 * within usb_ep_queue() as that can create deadlock situations.
 277 *
 278 * This routine may be called in interrupt context.
 279 *
 280 * Returns zero, or a negative error code.  Endpoints that are not enabled
 281 * report errors; errors will also be
 282 * reported when the usb peripheral is disconnected.
 283 *
 284 * If and only if @req is successfully queued (the return value is zero),
 285 * @req->complete() will be called exactly once, when the Gadget core and
 286 * UDC are finished with the request.  When the completion function is called,
 287 * control of the request is returned to the device driver which submitted it.
 288 * The completion handler may then immediately free or reuse @req.
 289 */
 290int usb_ep_queue(struct usb_ep *ep,
 291			       struct usb_request *req, gfp_t gfp_flags)
 292{
 293	int ret = 0;
 294
 295	if (WARN_ON_ONCE(!ep->enabled && ep->address)) {
 296		ret = -ESHUTDOWN;
 297		goto out;
 298	}
 299
 300	ret = ep->ops->queue(ep, req, gfp_flags);
 301
 302out:
 303	trace_usb_ep_queue(ep, req, ret);
 304
 305	return ret;
 306}
 307EXPORT_SYMBOL_GPL(usb_ep_queue);
 308
 309/**
 310 * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
 311 * @ep:the endpoint associated with the request
 312 * @req:the request being canceled
 313 *
 314 * If the request is still active on the endpoint, it is dequeued and
 315 * eventually its completion routine is called (with status -ECONNRESET);
 316 * else a negative error code is returned.  This routine is asynchronous,
 317 * that is, it may return before the completion routine runs.
 318 *
 319 * Note that some hardware can't clear out write fifos (to unlink the request
 320 * at the head of the queue) except as part of disconnecting from usb. Such
 321 * restrictions prevent drivers from supporting configuration changes,
 322 * even to configuration zero (a "chapter 9" requirement).
 323 *
 324 * This routine may be called in interrupt context.
 325 */
 326int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
 327{
 328	int ret;
 329
 330	ret = ep->ops->dequeue(ep, req);
 331	trace_usb_ep_dequeue(ep, req, ret);
 332
 333	return ret;
 334}
 335EXPORT_SYMBOL_GPL(usb_ep_dequeue);
 336
 337/**
 338 * usb_ep_set_halt - sets the endpoint halt feature.
 339 * @ep: the non-isochronous endpoint being stalled
 340 *
 341 * Use this to stall an endpoint, perhaps as an error report.
 342 * Except for control endpoints,
 343 * the endpoint stays halted (will not stream any data) until the host
 344 * clears this feature; drivers may need to empty the endpoint's request
 345 * queue first, to make sure no inappropriate transfers happen.
 346 *
 347 * Note that while an endpoint CLEAR_FEATURE will be invisible to the
 348 * gadget driver, a SET_INTERFACE will not be.  To reset endpoints for the
 349 * current altsetting, see usb_ep_clear_halt().  When switching altsettings,
 350 * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
 351 *
 352 * This routine may be called in interrupt context.
 353 *
 354 * Returns zero, or a negative error code.  On success, this call sets
 355 * underlying hardware state that blocks data transfers.
 356 * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
 357 * transfer requests are still queued, or if the controller hardware
 358 * (usually a FIFO) still holds bytes that the host hasn't collected.
 359 */
 360int usb_ep_set_halt(struct usb_ep *ep)
 361{
 362	int ret;
 363
 364	ret = ep->ops->set_halt(ep, 1);
 365	trace_usb_ep_set_halt(ep, ret);
 366
 367	return ret;
 368}
 369EXPORT_SYMBOL_GPL(usb_ep_set_halt);
 370
 371/**
 372 * usb_ep_clear_halt - clears endpoint halt, and resets toggle
 373 * @ep:the bulk or interrupt endpoint being reset
 374 *
 375 * Use this when responding to the standard usb "set interface" request,
 376 * for endpoints that aren't reconfigured, after clearing any other state
 377 * in the endpoint's i/o queue.
 378 *
 379 * This routine may be called in interrupt context.
 380 *
 381 * Returns zero, or a negative error code.  On success, this call clears
 382 * the underlying hardware state reflecting endpoint halt and data toggle.
 383 * Note that some hardware can't support this request (like pxa2xx_udc),
 384 * and accordingly can't correctly implement interface altsettings.
 385 */
 386int usb_ep_clear_halt(struct usb_ep *ep)
 387{
 388	int ret;
 389
 390	ret = ep->ops->set_halt(ep, 0);
 391	trace_usb_ep_clear_halt(ep, ret);
 392
 393	return ret;
 394}
 395EXPORT_SYMBOL_GPL(usb_ep_clear_halt);
 396
 397/**
 398 * usb_ep_set_wedge - sets the halt feature and ignores clear requests
 399 * @ep: the endpoint being wedged
 400 *
 401 * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT)
 402 * requests. If the gadget driver clears the halt status, it will
 403 * automatically unwedge the endpoint.
 404 *
 405 * This routine may be called in interrupt context.
 406 *
 407 * Returns zero on success, else negative errno.
 408 */
 409int usb_ep_set_wedge(struct usb_ep *ep)
 410{
 411	int ret;
 412
 413	if (ep->ops->set_wedge)
 414		ret = ep->ops->set_wedge(ep);
 415	else
 416		ret = ep->ops->set_halt(ep, 1);
 417
 418	trace_usb_ep_set_wedge(ep, ret);
 419
 420	return ret;
 421}
 422EXPORT_SYMBOL_GPL(usb_ep_set_wedge);
 423
 424/**
 425 * usb_ep_fifo_status - returns number of bytes in fifo, or error
 426 * @ep: the endpoint whose fifo status is being checked.
 427 *
 428 * FIFO endpoints may have "unclaimed data" in them in certain cases,
 429 * such as after aborted transfers.  Hosts may not have collected all
 430 * the IN data written by the gadget driver (and reported by a request
 431 * completion).  The gadget driver may not have collected all the data
 432 * written OUT to it by the host.  Drivers that need precise handling for
 433 * fault reporting or recovery may need to use this call.
 434 *
 435 * This routine may be called in interrupt context.
 436 *
 437 * This returns the number of such bytes in the fifo, or a negative
 438 * errno if the endpoint doesn't use a FIFO or doesn't support such
 439 * precise handling.
 440 */
 441int usb_ep_fifo_status(struct usb_ep *ep)
 442{
 443	int ret;
 444
 445	if (ep->ops->fifo_status)
 446		ret = ep->ops->fifo_status(ep);
 447	else
 448		ret = -EOPNOTSUPP;
 449
 450	trace_usb_ep_fifo_status(ep, ret);
 451
 452	return ret;
 453}
 454EXPORT_SYMBOL_GPL(usb_ep_fifo_status);
 455
 456/**
 457 * usb_ep_fifo_flush - flushes contents of a fifo
 458 * @ep: the endpoint whose fifo is being flushed.
 459 *
 460 * This call may be used to flush the "unclaimed data" that may exist in
 461 * an endpoint fifo after abnormal transaction terminations.  The call
 462 * must never be used except when endpoint is not being used for any
 463 * protocol translation.
 464 *
 465 * This routine may be called in interrupt context.
 466 */
 467void usb_ep_fifo_flush(struct usb_ep *ep)
 468{
 469	if (ep->ops->fifo_flush)
 470		ep->ops->fifo_flush(ep);
 471
 472	trace_usb_ep_fifo_flush(ep, 0);
 473}
 474EXPORT_SYMBOL_GPL(usb_ep_fifo_flush);
 475
 476/* ------------------------------------------------------------------------- */
 477
 478/**
 479 * usb_gadget_frame_number - returns the current frame number
 480 * @gadget: controller that reports the frame number
 481 *
 482 * Returns the usb frame number, normally eleven bits from a SOF packet,
 483 * or negative errno if this device doesn't support this capability.
 484 */
 485int usb_gadget_frame_number(struct usb_gadget *gadget)
 486{
 487	int ret;
 488
 489	ret = gadget->ops->get_frame(gadget);
 490
 491	trace_usb_gadget_frame_number(gadget, ret);
 492
 493	return ret;
 494}
 495EXPORT_SYMBOL_GPL(usb_gadget_frame_number);
 496
 497/**
 498 * usb_gadget_wakeup - tries to wake up the host connected to this gadget
 499 * @gadget: controller used to wake up the host
 500 *
 501 * Returns zero on success, else negative error code if the hardware
 502 * doesn't support such attempts, or its support has not been enabled
 503 * by the usb host.  Drivers must return device descriptors that report
 504 * their ability to support this, or hosts won't enable it.
 505 *
 506 * This may also try to use SRP to wake the host and start enumeration,
 507 * even if OTG isn't otherwise in use.  OTG devices may also start
 508 * remote wakeup even when hosts don't explicitly enable it.
 509 */
 510int usb_gadget_wakeup(struct usb_gadget *gadget)
 511{
 512	int ret = 0;
 513
 514	if (!gadget->ops->wakeup) {
 515		ret = -EOPNOTSUPP;
 516		goto out;
 517	}
 518
 519	ret = gadget->ops->wakeup(gadget);
 520
 521out:
 522	trace_usb_gadget_wakeup(gadget, ret);
 523
 524	return ret;
 525}
 526EXPORT_SYMBOL_GPL(usb_gadget_wakeup);
 527
 528/**
 529 * usb_gadget_set_remote_wakeup - configures the device remote wakeup feature.
 530 * @gadget:the device being configured for remote wakeup
 531 * @set:value to be configured.
 532 *
 533 * set to one to enable remote wakeup feature and zero to disable it.
 534 *
 535 * returns zero on success, else negative errno.
 536 */
 537int usb_gadget_set_remote_wakeup(struct usb_gadget *gadget, int set)
 538{
 539	int ret = 0;
 540
 541	if (!gadget->ops->set_remote_wakeup) {
 542		ret = -EOPNOTSUPP;
 543		goto out;
 544	}
 545
 546	ret = gadget->ops->set_remote_wakeup(gadget, set);
 547
 548out:
 549	trace_usb_gadget_set_remote_wakeup(gadget, ret);
 550
 551	return ret;
 552}
 553EXPORT_SYMBOL_GPL(usb_gadget_set_remote_wakeup);
 554
 555/**
 556 * usb_gadget_set_selfpowered - sets the device selfpowered feature.
 557 * @gadget:the device being declared as self-powered
 558 *
 559 * this affects the device status reported by the hardware driver
 560 * to reflect that it now has a local power supply.
 561 *
 562 * returns zero on success, else negative errno.
 563 */
 564int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
 565{
 566	int ret = 0;
 567
 568	if (!gadget->ops->set_selfpowered) {
 569		ret = -EOPNOTSUPP;
 570		goto out;
 571	}
 572
 573	ret = gadget->ops->set_selfpowered(gadget, 1);
 574
 575out:
 576	trace_usb_gadget_set_selfpowered(gadget, ret);
 577
 578	return ret;
 579}
 580EXPORT_SYMBOL_GPL(usb_gadget_set_selfpowered);
 581
 582/**
 583 * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
 584 * @gadget:the device being declared as bus-powered
 585 *
 586 * this affects the device status reported by the hardware driver.
 587 * some hardware may not support bus-powered operation, in which
 588 * case this feature's value can never change.
 589 *
 590 * returns zero on success, else negative errno.
 591 */
 592int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
 593{
 594	int ret = 0;
 595
 596	if (!gadget->ops->set_selfpowered) {
 597		ret = -EOPNOTSUPP;
 598		goto out;
 599	}
 600
 601	ret = gadget->ops->set_selfpowered(gadget, 0);
 602
 603out:
 604	trace_usb_gadget_clear_selfpowered(gadget, ret);
 605
 606	return ret;
 607}
 608EXPORT_SYMBOL_GPL(usb_gadget_clear_selfpowered);
 609
 610/**
 611 * usb_gadget_vbus_connect - Notify controller that VBUS is powered
 612 * @gadget:The device which now has VBUS power.
 613 * Context: can sleep
 614 *
 615 * This call is used by a driver for an external transceiver (or GPIO)
 616 * that detects a VBUS power session starting.  Common responses include
 617 * resuming the controller, activating the D+ (or D-) pullup to let the
 618 * host detect that a USB device is attached, and starting to draw power
 619 * (8mA or possibly more, especially after SET_CONFIGURATION).
 620 *
 621 * Returns zero on success, else negative errno.
 622 */
 623int usb_gadget_vbus_connect(struct usb_gadget *gadget)
 624{
 625	int ret = 0;
 626
 627	if (!gadget->ops->vbus_session) {
 628		ret = -EOPNOTSUPP;
 629		goto out;
 630	}
 631
 632	ret = gadget->ops->vbus_session(gadget, 1);
 633
 634out:
 635	trace_usb_gadget_vbus_connect(gadget, ret);
 636
 637	return ret;
 638}
 639EXPORT_SYMBOL_GPL(usb_gadget_vbus_connect);
 640
 641/**
 642 * usb_gadget_vbus_draw - constrain controller's VBUS power usage
 643 * @gadget:The device whose VBUS usage is being described
 644 * @mA:How much current to draw, in milliAmperes.  This should be twice
 645 *	the value listed in the configuration descriptor bMaxPower field.
 646 *
 647 * This call is used by gadget drivers during SET_CONFIGURATION calls,
 648 * reporting how much power the device may consume.  For example, this
 649 * could affect how quickly batteries are recharged.
 650 *
 651 * Returns zero on success, else negative errno.
 652 */
 653int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
 654{
 655	int ret = 0;
 656
 657	if (!gadget->ops->vbus_draw) {
 658		ret = -EOPNOTSUPP;
 659		goto out;
 660	}
 661
 662	ret = gadget->ops->vbus_draw(gadget, mA);
 663	if (!ret)
 664		gadget->mA = mA;
 665
 666out:
 667	trace_usb_gadget_vbus_draw(gadget, ret);
 668
 669	return ret;
 670}
 671EXPORT_SYMBOL_GPL(usb_gadget_vbus_draw);
 672
 673/**
 674 * usb_gadget_vbus_disconnect - notify controller about VBUS session end
 675 * @gadget:the device whose VBUS supply is being described
 676 * Context: can sleep
 677 *
 678 * This call is used by a driver for an external transceiver (or GPIO)
 679 * that detects a VBUS power session ending.  Common responses include
 680 * reversing everything done in usb_gadget_vbus_connect().
 681 *
 682 * Returns zero on success, else negative errno.
 683 */
 684int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
 685{
 686	int ret = 0;
 687
 688	if (!gadget->ops->vbus_session) {
 689		ret = -EOPNOTSUPP;
 690		goto out;
 691	}
 692
 693	ret = gadget->ops->vbus_session(gadget, 0);
 694
 695out:
 696	trace_usb_gadget_vbus_disconnect(gadget, ret);
 697
 698	return ret;
 699}
 700EXPORT_SYMBOL_GPL(usb_gadget_vbus_disconnect);
 701
 702static int usb_gadget_connect_locked(struct usb_gadget *gadget)
 703	__must_hold(&gadget->udc->connect_lock)
 
 
 
 
 
 
 
 
 
 704{
 705	int ret = 0;
 706
 707	if (!gadget->ops->pullup) {
 708		ret = -EOPNOTSUPP;
 709		goto out;
 710	}
 711
 712	if (gadget->deactivated || !gadget->udc->allow_connect || !gadget->udc->started) {
 713		/*
 714		 * If the gadget isn't usable (because it is deactivated,
 715		 * unbound, or not yet started), we only save the new state.
 716		 * The gadget will be connected automatically when it is
 717		 * activated/bound/started.
 718		 */
 719		gadget->connected = true;
 720		goto out;
 721	}
 722
 723	ret = gadget->ops->pullup(gadget, 1);
 724	if (!ret)
 725		gadget->connected = 1;
 726
 727out:
 728	trace_usb_gadget_connect(gadget, ret);
 729
 730	return ret;
 731}
 
 732
 733/**
 734 * usb_gadget_connect - software-controlled connect to USB host
 735 * @gadget:the peripheral being connected
 736 *
 737 * Enables the D+ (or potentially D-) pullup.  The host will start
 738 * enumerating this gadget when the pullup is active and a VBUS session
 739 * is active (the link is powered).
 
 
 
 740 *
 741 * Returns zero on success, else negative errno.
 742 */
 743int usb_gadget_connect(struct usb_gadget *gadget)
 744{
 745	int ret;
 746
 747	mutex_lock(&gadget->udc->connect_lock);
 748	ret = usb_gadget_connect_locked(gadget);
 749	mutex_unlock(&gadget->udc->connect_lock);
 750
 751	return ret;
 752}
 753EXPORT_SYMBOL_GPL(usb_gadget_connect);
 754
 755static int usb_gadget_disconnect_locked(struct usb_gadget *gadget)
 756	__must_hold(&gadget->udc->connect_lock)
 757{
 758	int ret = 0;
 759
 760	if (!gadget->ops->pullup) {
 761		ret = -EOPNOTSUPP;
 762		goto out;
 763	}
 764
 765	if (!gadget->connected)
 766		goto out;
 767
 768	if (gadget->deactivated || !gadget->udc->started) {
 769		/*
 770		 * If gadget is deactivated we only save new state.
 771		 * Gadget will stay disconnected after activation.
 772		 */
 773		gadget->connected = false;
 774		goto out;
 775	}
 776
 777	ret = gadget->ops->pullup(gadget, 0);
 778	if (!ret)
 779		gadget->connected = 0;
 780
 781	mutex_lock(&udc_lock);
 782	if (gadget->udc->driver)
 783		gadget->udc->driver->disconnect(gadget);
 784	mutex_unlock(&udc_lock);
 785
 786out:
 787	trace_usb_gadget_disconnect(gadget, ret);
 788
 789	return ret;
 790}
 791
 792/**
 793 * usb_gadget_disconnect - software-controlled disconnect from USB host
 794 * @gadget:the peripheral being disconnected
 795 *
 796 * Disables the D+ (or potentially D-) pullup, which the host may see
 797 * as a disconnect (when a VBUS session is active).  Not all systems
 798 * support software pullup controls.
 799 *
 800 * Following a successful disconnect, invoke the ->disconnect() callback
 801 * for the current gadget driver so that UDC drivers don't need to.
 802 *
 803 * Returns zero on success, else negative errno.
 804 */
 805int usb_gadget_disconnect(struct usb_gadget *gadget)
 806{
 807	int ret;
 808
 809	mutex_lock(&gadget->udc->connect_lock);
 810	ret = usb_gadget_disconnect_locked(gadget);
 811	mutex_unlock(&gadget->udc->connect_lock);
 812
 813	return ret;
 814}
 815EXPORT_SYMBOL_GPL(usb_gadget_disconnect);
 816
 817/**
 818 * usb_gadget_deactivate - deactivate function which is not ready to work
 819 * @gadget: the peripheral being deactivated
 820 *
 821 * This routine may be used during the gadget driver bind() call to prevent
 822 * the peripheral from ever being visible to the USB host, unless later
 823 * usb_gadget_activate() is called.  For example, user mode components may
 824 * need to be activated before the system can talk to hosts.
 825 *
 826 * This routine may sleep; it must not be called in interrupt context
 827 * (such as from within a gadget driver's disconnect() callback).
 828 *
 829 * Returns zero on success, else negative errno.
 830 */
 831int usb_gadget_deactivate(struct usb_gadget *gadget)
 832{
 833	int ret = 0;
 834
 835	mutex_lock(&gadget->udc->connect_lock);
 836	if (gadget->deactivated)
 837		goto unlock;
 838
 839	if (gadget->connected) {
 840		ret = usb_gadget_disconnect_locked(gadget);
 841		if (ret)
 842			goto unlock;
 843
 844		/*
 845		 * If gadget was being connected before deactivation, we want
 846		 * to reconnect it in usb_gadget_activate().
 847		 */
 848		gadget->connected = true;
 849	}
 850	gadget->deactivated = true;
 851
 852unlock:
 853	mutex_unlock(&gadget->udc->connect_lock);
 854	trace_usb_gadget_deactivate(gadget, ret);
 855
 856	return ret;
 857}
 858EXPORT_SYMBOL_GPL(usb_gadget_deactivate);
 859
 860/**
 861 * usb_gadget_activate - activate function which is not ready to work
 862 * @gadget: the peripheral being activated
 863 *
 864 * This routine activates gadget which was previously deactivated with
 865 * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed.
 866 *
 867 * This routine may sleep; it must not be called in interrupt context.
 868 *
 869 * Returns zero on success, else negative errno.
 870 */
 871int usb_gadget_activate(struct usb_gadget *gadget)
 872{
 873	int ret = 0;
 874
 875	mutex_lock(&gadget->udc->connect_lock);
 876	if (!gadget->deactivated)
 877		goto unlock;
 878
 879	gadget->deactivated = false;
 880
 881	/*
 882	 * If gadget has been connected before deactivation, or became connected
 883	 * while it was being deactivated, we call usb_gadget_connect().
 884	 */
 885	if (gadget->connected)
 886		ret = usb_gadget_connect_locked(gadget);
 887
 888unlock:
 889	mutex_unlock(&gadget->udc->connect_lock);
 890	trace_usb_gadget_activate(gadget, ret);
 891
 892	return ret;
 893}
 894EXPORT_SYMBOL_GPL(usb_gadget_activate);
 895
 896/* ------------------------------------------------------------------------- */
 897
 898#ifdef	CONFIG_HAS_DMA
 899
 900int usb_gadget_map_request_by_dev(struct device *dev,
 901		struct usb_request *req, int is_in)
 902{
 903	if (req->length == 0)
 904		return 0;
 905
 906	if (req->num_sgs) {
 907		int     mapped;
 908
 909		mapped = dma_map_sg(dev, req->sg, req->num_sgs,
 910				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 911		if (mapped == 0) {
 912			dev_err(dev, "failed to map SGs\n");
 913			return -EFAULT;
 914		}
 915
 916		req->num_mapped_sgs = mapped;
 917	} else {
 918		if (is_vmalloc_addr(req->buf)) {
 919			dev_err(dev, "buffer is not dma capable\n");
 920			return -EFAULT;
 921		} else if (object_is_on_stack(req->buf)) {
 922			dev_err(dev, "buffer is on stack\n");
 923			return -EFAULT;
 924		}
 925
 926		req->dma = dma_map_single(dev, req->buf, req->length,
 927				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 928
 929		if (dma_mapping_error(dev, req->dma)) {
 930			dev_err(dev, "failed to map buffer\n");
 931			return -EFAULT;
 932		}
 933
 934		req->dma_mapped = 1;
 935	}
 936
 937	return 0;
 938}
 939EXPORT_SYMBOL_GPL(usb_gadget_map_request_by_dev);
 940
 941int usb_gadget_map_request(struct usb_gadget *gadget,
 942		struct usb_request *req, int is_in)
 943{
 944	return usb_gadget_map_request_by_dev(gadget->dev.parent, req, is_in);
 945}
 946EXPORT_SYMBOL_GPL(usb_gadget_map_request);
 947
 948void usb_gadget_unmap_request_by_dev(struct device *dev,
 949		struct usb_request *req, int is_in)
 950{
 951	if (req->length == 0)
 952		return;
 953
 954	if (req->num_mapped_sgs) {
 955		dma_unmap_sg(dev, req->sg, req->num_sgs,
 956				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 957
 958		req->num_mapped_sgs = 0;
 959	} else if (req->dma_mapped) {
 960		dma_unmap_single(dev, req->dma, req->length,
 961				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 962		req->dma_mapped = 0;
 963	}
 964}
 965EXPORT_SYMBOL_GPL(usb_gadget_unmap_request_by_dev);
 966
 967void usb_gadget_unmap_request(struct usb_gadget *gadget,
 968		struct usb_request *req, int is_in)
 969{
 970	usb_gadget_unmap_request_by_dev(gadget->dev.parent, req, is_in);
 971}
 972EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);
 973
 974#endif	/* CONFIG_HAS_DMA */
 975
 976/* ------------------------------------------------------------------------- */
 977
 978/**
 979 * usb_gadget_giveback_request - give the request back to the gadget layer
 980 * @ep: the endpoint to be used with with the request
 981 * @req: the request being given back
 982 *
 983 * This is called by device controller drivers in order to return the
 984 * completed request back to the gadget layer.
 985 */
 986void usb_gadget_giveback_request(struct usb_ep *ep,
 987		struct usb_request *req)
 988{
 989	if (likely(req->status == 0))
 990		usb_led_activity(USB_LED_EVENT_GADGET);
 991
 992	trace_usb_gadget_giveback_request(ep, req, 0);
 993
 994	req->complete(ep, req);
 995}
 996EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
 997
 998/* ------------------------------------------------------------------------- */
 999
1000/**
1001 * gadget_find_ep_by_name - returns ep whose name is the same as sting passed
1002 *	in second parameter or NULL if searched endpoint not found
1003 * @g: controller to check for quirk
1004 * @name: name of searched endpoint
1005 */
1006struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g, const char *name)
1007{
1008	struct usb_ep *ep;
1009
1010	gadget_for_each_ep(ep, g) {
1011		if (!strcmp(ep->name, name))
1012			return ep;
1013	}
1014
1015	return NULL;
1016}
1017EXPORT_SYMBOL_GPL(gadget_find_ep_by_name);
1018
1019/* ------------------------------------------------------------------------- */
1020
1021int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
1022		struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
1023		struct usb_ss_ep_comp_descriptor *ep_comp)
1024{
1025	u8		type;
1026	u16		max;
1027	int		num_req_streams = 0;
1028
1029	/* endpoint already claimed? */
1030	if (ep->claimed)
1031		return 0;
1032
1033	type = usb_endpoint_type(desc);
1034	max = usb_endpoint_maxp(desc);
1035
1036	if (usb_endpoint_dir_in(desc) && !ep->caps.dir_in)
1037		return 0;
1038	if (usb_endpoint_dir_out(desc) && !ep->caps.dir_out)
1039		return 0;
1040
1041	if (max > ep->maxpacket_limit)
1042		return 0;
1043
1044	/* "high bandwidth" works only at high speed */
1045	if (!gadget_is_dualspeed(gadget) && usb_endpoint_maxp_mult(desc) > 1)
1046		return 0;
1047
1048	switch (type) {
1049	case USB_ENDPOINT_XFER_CONTROL:
1050		/* only support ep0 for portable CONTROL traffic */
1051		return 0;
1052	case USB_ENDPOINT_XFER_ISOC:
1053		if (!ep->caps.type_iso)
1054			return 0;
1055		/* ISO:  limit 1023 bytes full speed, 1024 high/super speed */
1056		if (!gadget_is_dualspeed(gadget) && max > 1023)
1057			return 0;
1058		break;
1059	case USB_ENDPOINT_XFER_BULK:
1060		if (!ep->caps.type_bulk)
1061			return 0;
1062		if (ep_comp && gadget_is_superspeed(gadget)) {
1063			/* Get the number of required streams from the
1064			 * EP companion descriptor and see if the EP
1065			 * matches it
1066			 */
1067			num_req_streams = ep_comp->bmAttributes & 0x1f;
1068			if (num_req_streams > ep->max_streams)
1069				return 0;
1070		}
1071		break;
1072	case USB_ENDPOINT_XFER_INT:
1073		/* Bulk endpoints handle interrupt transfers,
1074		 * except the toggle-quirky iso-synch kind
1075		 */
1076		if (!ep->caps.type_int && !ep->caps.type_bulk)
1077			return 0;
1078		/* INT:  limit 64 bytes full speed, 1024 high/super speed */
1079		if (!gadget_is_dualspeed(gadget) && max > 64)
1080			return 0;
1081		break;
1082	}
1083
1084	return 1;
1085}
1086EXPORT_SYMBOL_GPL(usb_gadget_ep_match_desc);
1087
1088/**
1089 * usb_gadget_check_config - checks if the UDC can support the binded
1090 *	configuration
1091 * @gadget: controller to check the USB configuration
1092 *
1093 * Ensure that a UDC is able to support the requested resources by a
1094 * configuration, and that there are no resource limitations, such as
1095 * internal memory allocated to all requested endpoints.
1096 *
1097 * Returns zero on success, else a negative errno.
1098 */
1099int usb_gadget_check_config(struct usb_gadget *gadget)
1100{
1101	if (gadget->ops->check_config)
1102		return gadget->ops->check_config(gadget);
1103	return 0;
1104}
1105EXPORT_SYMBOL_GPL(usb_gadget_check_config);
1106
1107/* ------------------------------------------------------------------------- */
1108
1109static void usb_gadget_state_work(struct work_struct *work)
1110{
1111	struct usb_gadget *gadget = work_to_gadget(work);
1112	struct usb_udc *udc = gadget->udc;
1113
1114	if (udc)
1115		sysfs_notify(&udc->dev.kobj, NULL, "state");
1116}
1117
1118void usb_gadget_set_state(struct usb_gadget *gadget,
1119		enum usb_device_state state)
1120{
1121	gadget->state = state;
1122	schedule_work(&gadget->work);
1123}
1124EXPORT_SYMBOL_GPL(usb_gadget_set_state);
1125
1126/* ------------------------------------------------------------------------- */
1127
1128/* Acquire connect_lock before calling this function. */
1129static int usb_udc_connect_control_locked(struct usb_udc *udc) __must_hold(&udc->connect_lock)
1130{
1131	if (udc->vbus)
1132		return usb_gadget_connect_locked(udc->gadget);
1133	else
1134		return usb_gadget_disconnect_locked(udc->gadget);
1135}
1136
1137static void vbus_event_work(struct work_struct *work)
1138{
1139	struct usb_udc *udc = container_of(work, struct usb_udc, vbus_work);
1140
1141	mutex_lock(&udc->connect_lock);
1142	usb_udc_connect_control_locked(udc);
1143	mutex_unlock(&udc->connect_lock);
1144}
1145
1146/**
1147 * usb_udc_vbus_handler - updates the udc core vbus status, and try to
1148 * connect or disconnect gadget
1149 * @gadget: The gadget which vbus change occurs
1150 * @status: The vbus status
1151 *
1152 * The udc driver calls it when it wants to connect or disconnect gadget
1153 * according to vbus status.
1154 *
1155 * This function can be invoked from interrupt context by irq handlers of
1156 * the gadget drivers, however, usb_udc_connect_control() has to run in
1157 * non-atomic context due to the following:
1158 * a. Some of the gadget driver implementations expect the ->pullup
1159 * callback to be invoked in non-atomic context.
1160 * b. usb_gadget_disconnect() acquires udc_lock which is a mutex.
1161 * Hence offload invocation of usb_udc_connect_control() to workqueue.
1162 */
1163void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status)
1164{
1165	struct usb_udc *udc = gadget->udc;
1166
1167	if (udc) {
1168		udc->vbus = status;
1169		schedule_work(&udc->vbus_work);
1170	}
1171}
1172EXPORT_SYMBOL_GPL(usb_udc_vbus_handler);
1173
1174/**
1175 * usb_gadget_udc_reset - notifies the udc core that bus reset occurs
1176 * @gadget: The gadget which bus reset occurs
1177 * @driver: The gadget driver we want to notify
1178 *
1179 * If the udc driver has bus reset handler, it needs to call this when the bus
1180 * reset occurs, it notifies the gadget driver that the bus reset occurs as
1181 * well as updates gadget state.
1182 */
1183void usb_gadget_udc_reset(struct usb_gadget *gadget,
1184		struct usb_gadget_driver *driver)
1185{
1186	driver->reset(gadget);
1187	usb_gadget_set_state(gadget, USB_STATE_DEFAULT);
1188}
1189EXPORT_SYMBOL_GPL(usb_gadget_udc_reset);
1190
1191/**
1192 * usb_gadget_udc_start_locked - tells usb device controller to start up
1193 * @udc: The UDC to be started
1194 *
1195 * This call is issued by the UDC Class driver when it's about
1196 * to register a gadget driver to the device controller, before
1197 * calling gadget driver's bind() method.
1198 *
1199 * It allows the controller to be powered off until strictly
1200 * necessary to have it powered on.
1201 *
1202 * Returns zero on success, else negative errno.
1203 *
1204 * Caller should acquire connect_lock before invoking this function.
1205 */
1206static inline int usb_gadget_udc_start_locked(struct usb_udc *udc)
1207	__must_hold(&udc->connect_lock)
1208{
1209	int ret;
1210
1211	if (udc->started) {
1212		dev_err(&udc->dev, "UDC had already started\n");
1213		return -EBUSY;
1214	}
1215
1216	ret = udc->gadget->ops->udc_start(udc->gadget, udc->driver);
1217	if (!ret)
1218		udc->started = true;
1219
1220	return ret;
1221}
1222
1223/**
1224 * usb_gadget_udc_stop_locked - tells usb device controller we don't need it anymore
1225 * @udc: The UDC to be stopped
1226 *
1227 * This call is issued by the UDC Class driver after calling
1228 * gadget driver's unbind() method.
1229 *
1230 * The details are implementation specific, but it can go as
1231 * far as powering off UDC completely and disable its data
1232 * line pullups.
1233 *
1234 * Caller should acquire connect lock before invoking this function.
1235 */
1236static inline void usb_gadget_udc_stop_locked(struct usb_udc *udc)
1237	__must_hold(&udc->connect_lock)
1238{
1239	if (!udc->started) {
1240		dev_err(&udc->dev, "UDC had already stopped\n");
1241		return;
1242	}
1243
1244	udc->gadget->ops->udc_stop(udc->gadget);
1245	udc->started = false;
1246}
1247
1248/**
1249 * usb_gadget_udc_set_speed - tells usb device controller speed supported by
1250 *    current driver
1251 * @udc: The device we want to set maximum speed
1252 * @speed: The maximum speed to allowed to run
1253 *
1254 * This call is issued by the UDC Class driver before calling
1255 * usb_gadget_udc_start() in order to make sure that we don't try to
1256 * connect on speeds the gadget driver doesn't support.
1257 */
1258static inline void usb_gadget_udc_set_speed(struct usb_udc *udc,
1259					    enum usb_device_speed speed)
1260{
1261	struct usb_gadget *gadget = udc->gadget;
1262	enum usb_device_speed s;
1263
1264	if (speed == USB_SPEED_UNKNOWN)
1265		s = gadget->max_speed;
1266	else
1267		s = min(speed, gadget->max_speed);
1268
1269	if (s == USB_SPEED_SUPER_PLUS && gadget->ops->udc_set_ssp_rate)
1270		gadget->ops->udc_set_ssp_rate(gadget, gadget->max_ssp_rate);
1271	else if (gadget->ops->udc_set_speed)
1272		gadget->ops->udc_set_speed(gadget, s);
1273}
1274
1275/**
1276 * usb_gadget_enable_async_callbacks - tell usb device controller to enable asynchronous callbacks
1277 * @udc: The UDC which should enable async callbacks
1278 *
1279 * This routine is used when binding gadget drivers.  It undoes the effect
1280 * of usb_gadget_disable_async_callbacks(); the UDC driver should enable IRQs
1281 * (if necessary) and resume issuing callbacks.
1282 *
1283 * This routine will always be called in process context.
1284 */
1285static inline void usb_gadget_enable_async_callbacks(struct usb_udc *udc)
1286{
1287	struct usb_gadget *gadget = udc->gadget;
1288
1289	if (gadget->ops->udc_async_callbacks)
1290		gadget->ops->udc_async_callbacks(gadget, true);
1291}
1292
1293/**
1294 * usb_gadget_disable_async_callbacks - tell usb device controller to disable asynchronous callbacks
1295 * @udc: The UDC which should disable async callbacks
1296 *
1297 * This routine is used when unbinding gadget drivers.  It prevents a race:
1298 * The UDC driver doesn't know when the gadget driver's ->unbind callback
1299 * runs, so unless it is told to disable asynchronous callbacks, it might
1300 * issue a callback (such as ->disconnect) after the unbind has completed.
1301 *
1302 * After this function runs, the UDC driver must suppress all ->suspend,
1303 * ->resume, ->disconnect, ->reset, and ->setup callbacks to the gadget driver
1304 * until async callbacks are again enabled.  A simple-minded but effective
1305 * way to accomplish this is to tell the UDC hardware not to generate any
1306 * more IRQs.
1307 *
1308 * Request completion callbacks must still be issued.  However, it's okay
1309 * to defer them until the request is cancelled, since the pull-up will be
1310 * turned off during the time period when async callbacks are disabled.
1311 *
1312 * This routine will always be called in process context.
1313 */
1314static inline void usb_gadget_disable_async_callbacks(struct usb_udc *udc)
1315{
1316	struct usb_gadget *gadget = udc->gadget;
1317
1318	if (gadget->ops->udc_async_callbacks)
1319		gadget->ops->udc_async_callbacks(gadget, false);
1320}
1321
1322/**
1323 * usb_udc_release - release the usb_udc struct
1324 * @dev: the dev member within usb_udc
1325 *
1326 * This is called by driver's core in order to free memory once the last
1327 * reference is released.
1328 */
1329static void usb_udc_release(struct device *dev)
1330{
1331	struct usb_udc *udc;
1332
1333	udc = container_of(dev, struct usb_udc, dev);
1334	dev_dbg(dev, "releasing '%s'\n", dev_name(dev));
1335	kfree(udc);
1336}
1337
1338static const struct attribute_group *usb_udc_attr_groups[];
1339
1340static void usb_udc_nop_release(struct device *dev)
1341{
1342	dev_vdbg(dev, "%s\n", __func__);
1343}
1344
1345/**
1346 * usb_initialize_gadget - initialize a gadget and its embedded struct device
1347 * @parent: the parent device to this udc. Usually the controller driver's
1348 * device.
1349 * @gadget: the gadget to be initialized.
1350 * @release: a gadget release function.
1351 */
1352void usb_initialize_gadget(struct device *parent, struct usb_gadget *gadget,
1353		void (*release)(struct device *dev))
1354{
1355	INIT_WORK(&gadget->work, usb_gadget_state_work);
1356	gadget->dev.parent = parent;
1357
1358	if (release)
1359		gadget->dev.release = release;
1360	else
1361		gadget->dev.release = usb_udc_nop_release;
1362
1363	device_initialize(&gadget->dev);
1364	gadget->dev.bus = &gadget_bus_type;
1365}
1366EXPORT_SYMBOL_GPL(usb_initialize_gadget);
1367
1368/**
1369 * usb_add_gadget - adds a new gadget to the udc class driver list
1370 * @gadget: the gadget to be added to the list.
1371 *
1372 * Returns zero on success, negative errno otherwise.
1373 * Does not do a final usb_put_gadget() if an error occurs.
1374 */
1375int usb_add_gadget(struct usb_gadget *gadget)
1376{
1377	struct usb_udc		*udc;
1378	int			ret = -ENOMEM;
1379
1380	udc = kzalloc(sizeof(*udc), GFP_KERNEL);
1381	if (!udc)
1382		goto error;
1383
1384	device_initialize(&udc->dev);
1385	udc->dev.release = usb_udc_release;
1386	udc->dev.class = &udc_class;
1387	udc->dev.groups = usb_udc_attr_groups;
1388	udc->dev.parent = gadget->dev.parent;
1389	ret = dev_set_name(&udc->dev, "%s",
1390			kobject_name(&gadget->dev.parent->kobj));
1391	if (ret)
1392		goto err_put_udc;
1393
1394	udc->gadget = gadget;
1395	gadget->udc = udc;
1396	mutex_init(&udc->connect_lock);
1397
1398	udc->started = false;
1399
1400	mutex_lock(&udc_lock);
1401	list_add_tail(&udc->list, &udc_list);
1402	mutex_unlock(&udc_lock);
1403	INIT_WORK(&udc->vbus_work, vbus_event_work);
1404
1405	ret = device_add(&udc->dev);
1406	if (ret)
1407		goto err_unlist_udc;
1408
1409	usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
1410	udc->vbus = true;
1411
1412	ret = ida_alloc(&gadget_id_numbers, GFP_KERNEL);
1413	if (ret < 0)
1414		goto err_del_udc;
1415	gadget->id_number = ret;
1416	dev_set_name(&gadget->dev, "gadget.%d", ret);
1417
1418	ret = device_add(&gadget->dev);
1419	if (ret)
1420		goto err_free_id;
1421
1422	return 0;
1423
1424 err_free_id:
1425	ida_free(&gadget_id_numbers, gadget->id_number);
1426
1427 err_del_udc:
1428	flush_work(&gadget->work);
1429	device_del(&udc->dev);
1430
1431 err_unlist_udc:
1432	mutex_lock(&udc_lock);
1433	list_del(&udc->list);
1434	mutex_unlock(&udc_lock);
1435
1436 err_put_udc:
1437	put_device(&udc->dev);
1438
1439 error:
1440	return ret;
1441}
1442EXPORT_SYMBOL_GPL(usb_add_gadget);
1443
1444/**
1445 * usb_add_gadget_udc_release - adds a new gadget to the udc class driver list
1446 * @parent: the parent device to this udc. Usually the controller driver's
1447 * device.
1448 * @gadget: the gadget to be added to the list.
1449 * @release: a gadget release function.
1450 *
1451 * Returns zero on success, negative errno otherwise.
1452 * Calls the gadget release function in the latter case.
1453 */
1454int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
1455		void (*release)(struct device *dev))
1456{
1457	int	ret;
1458
1459	usb_initialize_gadget(parent, gadget, release);
1460	ret = usb_add_gadget(gadget);
1461	if (ret)
1462		usb_put_gadget(gadget);
1463	return ret;
1464}
1465EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release);
1466
1467/**
1468 * usb_get_gadget_udc_name - get the name of the first UDC controller
1469 * This functions returns the name of the first UDC controller in the system.
1470 * Please note that this interface is usefull only for legacy drivers which
1471 * assume that there is only one UDC controller in the system and they need to
1472 * get its name before initialization. There is no guarantee that the UDC
1473 * of the returned name will be still available, when gadget driver registers
1474 * itself.
1475 *
1476 * Returns pointer to string with UDC controller name on success, NULL
1477 * otherwise. Caller should kfree() returned string.
1478 */
1479char *usb_get_gadget_udc_name(void)
1480{
1481	struct usb_udc *udc;
1482	char *name = NULL;
1483
1484	/* For now we take the first available UDC */
1485	mutex_lock(&udc_lock);
1486	list_for_each_entry(udc, &udc_list, list) {
1487		if (!udc->driver) {
1488			name = kstrdup(udc->gadget->name, GFP_KERNEL);
1489			break;
1490		}
1491	}
1492	mutex_unlock(&udc_lock);
1493	return name;
1494}
1495EXPORT_SYMBOL_GPL(usb_get_gadget_udc_name);
1496
1497/**
1498 * usb_add_gadget_udc - adds a new gadget to the udc class driver list
1499 * @parent: the parent device to this udc. Usually the controller
1500 * driver's device.
1501 * @gadget: the gadget to be added to the list
1502 *
1503 * Returns zero on success, negative errno otherwise.
1504 */
1505int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
1506{
1507	return usb_add_gadget_udc_release(parent, gadget, NULL);
1508}
1509EXPORT_SYMBOL_GPL(usb_add_gadget_udc);
1510
1511/**
1512 * usb_del_gadget - deletes a gadget and unregisters its udc
1513 * @gadget: the gadget to be deleted.
1514 *
1515 * This will unbind @gadget, if it is bound.
1516 * It will not do a final usb_put_gadget().
1517 */
1518void usb_del_gadget(struct usb_gadget *gadget)
1519{
1520	struct usb_udc *udc = gadget->udc;
1521
1522	if (!udc)
1523		return;
1524
1525	dev_vdbg(gadget->dev.parent, "unregistering gadget\n");
1526
1527	mutex_lock(&udc_lock);
1528	list_del(&udc->list);
1529	mutex_unlock(&udc_lock);
1530
1531	kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
1532	flush_work(&gadget->work);
1533	device_del(&gadget->dev);
1534	ida_free(&gadget_id_numbers, gadget->id_number);
1535	cancel_work_sync(&udc->vbus_work);
1536	device_unregister(&udc->dev);
1537}
1538EXPORT_SYMBOL_GPL(usb_del_gadget);
1539
1540/**
1541 * usb_del_gadget_udc - unregisters a gadget
1542 * @gadget: the gadget to be unregistered.
1543 *
1544 * Calls usb_del_gadget() and does a final usb_put_gadget().
1545 */
1546void usb_del_gadget_udc(struct usb_gadget *gadget)
1547{
1548	usb_del_gadget(gadget);
1549	usb_put_gadget(gadget);
1550}
1551EXPORT_SYMBOL_GPL(usb_del_gadget_udc);
1552
1553/* ------------------------------------------------------------------------- */
1554
1555static int gadget_match_driver(struct device *dev, struct device_driver *drv)
1556{
1557	struct usb_gadget *gadget = dev_to_usb_gadget(dev);
1558	struct usb_udc *udc = gadget->udc;
1559	struct usb_gadget_driver *driver = container_of(drv,
1560			struct usb_gadget_driver, driver);
1561
1562	/* If the driver specifies a udc_name, it must match the UDC's name */
1563	if (driver->udc_name &&
1564			strcmp(driver->udc_name, dev_name(&udc->dev)) != 0)
1565		return 0;
1566
1567	/* If the driver is already bound to a gadget, it doesn't match */
1568	if (driver->is_bound)
1569		return 0;
1570
1571	/* Otherwise any gadget driver matches any UDC */
1572	return 1;
1573}
1574
1575static int gadget_bind_driver(struct device *dev)
1576{
1577	struct usb_gadget *gadget = dev_to_usb_gadget(dev);
1578	struct usb_udc *udc = gadget->udc;
1579	struct usb_gadget_driver *driver = container_of(dev->driver,
1580			struct usb_gadget_driver, driver);
1581	int ret = 0;
1582
1583	mutex_lock(&udc_lock);
1584	if (driver->is_bound) {
1585		mutex_unlock(&udc_lock);
1586		return -ENXIO;		/* Driver binds to only one gadget */
1587	}
1588	driver->is_bound = true;
1589	udc->driver = driver;
1590	mutex_unlock(&udc_lock);
1591
1592	dev_dbg(&udc->dev, "binding gadget driver [%s]\n", driver->function);
1593
1594	usb_gadget_udc_set_speed(udc, driver->max_speed);
1595
1596	ret = driver->bind(udc->gadget, driver);
1597	if (ret)
1598		goto err_bind;
1599
1600	mutex_lock(&udc->connect_lock);
1601	ret = usb_gadget_udc_start_locked(udc);
1602	if (ret) {
1603		mutex_unlock(&udc->connect_lock);
1604		goto err_start;
1605	}
1606	usb_gadget_enable_async_callbacks(udc);
1607	udc->allow_connect = true;
1608	ret = usb_udc_connect_control_locked(udc);
1609	if (ret)
1610		goto err_connect_control;
1611
1612	mutex_unlock(&udc->connect_lock);
1613
1614	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
1615	return 0;
1616
1617 err_connect_control:
1618	udc->allow_connect = false;
1619	usb_gadget_disable_async_callbacks(udc);
1620	if (gadget->irq)
1621		synchronize_irq(gadget->irq);
1622	usb_gadget_udc_stop_locked(udc);
1623	mutex_unlock(&udc->connect_lock);
1624
1625 err_start:
1626	driver->unbind(udc->gadget);
1627
1628 err_bind:
1629	if (ret != -EISNAM)
1630		dev_err(&udc->dev, "failed to start %s: %d\n",
1631			driver->function, ret);
1632
1633	mutex_lock(&udc_lock);
1634	udc->driver = NULL;
1635	driver->is_bound = false;
1636	mutex_unlock(&udc_lock);
1637
1638	return ret;
1639}
1640
1641static void gadget_unbind_driver(struct device *dev)
1642{
1643	struct usb_gadget *gadget = dev_to_usb_gadget(dev);
1644	struct usb_udc *udc = gadget->udc;
1645	struct usb_gadget_driver *driver = udc->driver;
1646
1647	dev_dbg(&udc->dev, "unbinding gadget driver [%s]\n", driver->function);
1648
1649	udc->allow_connect = false;
1650	cancel_work_sync(&udc->vbus_work);
1651	mutex_lock(&udc->connect_lock);
1652	usb_gadget_disconnect_locked(gadget);
1653	usb_gadget_disable_async_callbacks(udc);
1654	if (gadget->irq)
1655		synchronize_irq(gadget->irq);
1656	mutex_unlock(&udc->connect_lock);
1657
1658	udc->driver->unbind(gadget);
1659
1660	mutex_lock(&udc->connect_lock);
1661	usb_gadget_udc_stop_locked(udc);
1662	mutex_unlock(&udc->connect_lock);
1663
1664	mutex_lock(&udc_lock);
1665	driver->is_bound = false;
1666	udc->driver = NULL;
1667	mutex_unlock(&udc_lock);
1668
1669	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
1670}
1671
1672/* ------------------------------------------------------------------------- */
1673
1674int usb_gadget_register_driver_owner(struct usb_gadget_driver *driver,
1675		struct module *owner, const char *mod_name)
1676{
1677	int ret;
1678
1679	if (!driver || !driver->bind || !driver->setup)
1680		return -EINVAL;
1681
1682	driver->driver.bus = &gadget_bus_type;
1683	driver->driver.owner = owner;
1684	driver->driver.mod_name = mod_name;
1685	ret = driver_register(&driver->driver);
1686	if (ret) {
1687		pr_warn("%s: driver registration failed: %d\n",
1688				driver->function, ret);
1689		return ret;
1690	}
1691
1692	mutex_lock(&udc_lock);
1693	if (!driver->is_bound) {
1694		if (driver->match_existing_only) {
1695			pr_warn("%s: couldn't find an available UDC or it's busy\n",
1696					driver->function);
1697			ret = -EBUSY;
1698		} else {
1699			pr_info("%s: couldn't find an available UDC\n",
1700					driver->function);
1701			ret = 0;
1702		}
1703	}
1704	mutex_unlock(&udc_lock);
1705
1706	if (ret)
1707		driver_unregister(&driver->driver);
1708	return ret;
1709}
1710EXPORT_SYMBOL_GPL(usb_gadget_register_driver_owner);
1711
1712int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
1713{
1714	if (!driver || !driver->unbind)
1715		return -EINVAL;
1716
1717	driver_unregister(&driver->driver);
1718	return 0;
1719}
1720EXPORT_SYMBOL_GPL(usb_gadget_unregister_driver);
1721
1722/* ------------------------------------------------------------------------- */
1723
1724static ssize_t srp_store(struct device *dev,
1725		struct device_attribute *attr, const char *buf, size_t n)
1726{
1727	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
1728
1729	if (sysfs_streq(buf, "1"))
1730		usb_gadget_wakeup(udc->gadget);
1731
1732	return n;
1733}
1734static DEVICE_ATTR_WO(srp);
1735
1736static ssize_t soft_connect_store(struct device *dev,
1737		struct device_attribute *attr, const char *buf, size_t n)
1738{
1739	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
1740	ssize_t			ret;
1741
1742	device_lock(&udc->gadget->dev);
1743	if (!udc->driver) {
1744		dev_err(dev, "soft-connect without a gadget driver\n");
1745		ret = -EOPNOTSUPP;
1746		goto out;
1747	}
1748
1749	if (sysfs_streq(buf, "connect")) {
1750		mutex_lock(&udc->connect_lock);
1751		usb_gadget_udc_start_locked(udc);
1752		usb_gadget_connect_locked(udc->gadget);
1753		mutex_unlock(&udc->connect_lock);
1754	} else if (sysfs_streq(buf, "disconnect")) {
1755		mutex_lock(&udc->connect_lock);
1756		usb_gadget_disconnect_locked(udc->gadget);
1757		usb_gadget_udc_stop_locked(udc);
1758		mutex_unlock(&udc->connect_lock);
1759	} else {
1760		dev_err(dev, "unsupported command '%s'\n", buf);
1761		ret = -EINVAL;
1762		goto out;
1763	}
1764
1765	ret = n;
1766out:
1767	device_unlock(&udc->gadget->dev);
1768	return ret;
1769}
1770static DEVICE_ATTR_WO(soft_connect);
1771
1772static ssize_t state_show(struct device *dev, struct device_attribute *attr,
1773			  char *buf)
1774{
1775	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
1776	struct usb_gadget	*gadget = udc->gadget;
1777
1778	return sprintf(buf, "%s\n", usb_state_string(gadget->state));
1779}
1780static DEVICE_ATTR_RO(state);
1781
1782static ssize_t function_show(struct device *dev, struct device_attribute *attr,
1783			     char *buf)
1784{
1785	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
1786	struct usb_gadget_driver *drv;
1787	int			rc = 0;
1788
1789	mutex_lock(&udc_lock);
1790	drv = udc->driver;
1791	if (drv && drv->function)
1792		rc = scnprintf(buf, PAGE_SIZE, "%s\n", drv->function);
1793	mutex_unlock(&udc_lock);
1794	return rc;
1795}
1796static DEVICE_ATTR_RO(function);
1797
1798#define USB_UDC_SPEED_ATTR(name, param)					\
1799ssize_t name##_show(struct device *dev,					\
1800		struct device_attribute *attr, char *buf)		\
1801{									\
1802	struct usb_udc *udc = container_of(dev, struct usb_udc, dev);	\
1803	return scnprintf(buf, PAGE_SIZE, "%s\n",			\
1804			usb_speed_string(udc->gadget->param));		\
1805}									\
1806static DEVICE_ATTR_RO(name)
1807
1808static USB_UDC_SPEED_ATTR(current_speed, speed);
1809static USB_UDC_SPEED_ATTR(maximum_speed, max_speed);
1810
1811#define USB_UDC_ATTR(name)					\
1812ssize_t name##_show(struct device *dev,				\
1813		struct device_attribute *attr, char *buf)	\
1814{								\
1815	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev); \
1816	struct usb_gadget	*gadget = udc->gadget;		\
1817								\
1818	return scnprintf(buf, PAGE_SIZE, "%d\n", gadget->name);	\
1819}								\
1820static DEVICE_ATTR_RO(name)
1821
1822static USB_UDC_ATTR(is_otg);
1823static USB_UDC_ATTR(is_a_peripheral);
1824static USB_UDC_ATTR(b_hnp_enable);
1825static USB_UDC_ATTR(a_hnp_support);
1826static USB_UDC_ATTR(a_alt_hnp_support);
1827static USB_UDC_ATTR(is_selfpowered);
1828
1829static struct attribute *usb_udc_attrs[] = {
1830	&dev_attr_srp.attr,
1831	&dev_attr_soft_connect.attr,
1832	&dev_attr_state.attr,
1833	&dev_attr_function.attr,
1834	&dev_attr_current_speed.attr,
1835	&dev_attr_maximum_speed.attr,
1836
1837	&dev_attr_is_otg.attr,
1838	&dev_attr_is_a_peripheral.attr,
1839	&dev_attr_b_hnp_enable.attr,
1840	&dev_attr_a_hnp_support.attr,
1841	&dev_attr_a_alt_hnp_support.attr,
1842	&dev_attr_is_selfpowered.attr,
1843	NULL,
1844};
1845
1846static const struct attribute_group usb_udc_attr_group = {
1847	.attrs = usb_udc_attrs,
1848};
1849
1850static const struct attribute_group *usb_udc_attr_groups[] = {
1851	&usb_udc_attr_group,
1852	NULL,
1853};
1854
1855static int usb_udc_uevent(const struct device *dev, struct kobj_uevent_env *env)
1856{
1857	const struct usb_udc	*udc = container_of(dev, struct usb_udc, dev);
1858	int			ret;
1859
1860	ret = add_uevent_var(env, "USB_UDC_NAME=%s", udc->gadget->name);
1861	if (ret) {
1862		dev_err(dev, "failed to add uevent USB_UDC_NAME\n");
1863		return ret;
1864	}
1865
1866	mutex_lock(&udc_lock);
1867	if (udc->driver)
1868		ret = add_uevent_var(env, "USB_UDC_DRIVER=%s",
1869				udc->driver->function);
1870	mutex_unlock(&udc_lock);
1871	if (ret) {
1872		dev_err(dev, "failed to add uevent USB_UDC_DRIVER\n");
1873		return ret;
1874	}
1875
1876	return 0;
1877}
1878
1879static const struct class udc_class = {
1880	.name		= "udc",
1881	.dev_uevent	= usb_udc_uevent,
1882};
1883
1884static const struct bus_type gadget_bus_type = {
1885	.name = "gadget",
1886	.probe = gadget_bind_driver,
1887	.remove = gadget_unbind_driver,
1888	.match = gadget_match_driver,
1889};
1890
1891static int __init usb_udc_init(void)
1892{
1893	int rc;
1894
1895	rc = class_register(&udc_class);
1896	if (rc)
1897		return rc;
 
 
 
 
 
1898
1899	rc = bus_register(&gadget_bus_type);
1900	if (rc)
1901		class_unregister(&udc_class);
1902	return rc;
1903}
1904subsys_initcall(usb_udc_init);
1905
1906static void __exit usb_udc_exit(void)
1907{
1908	bus_unregister(&gadget_bus_type);
1909	class_unregister(&udc_class);
1910}
1911module_exit(usb_udc_exit);
1912
1913MODULE_DESCRIPTION("UDC Framework");
1914MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
1915MODULE_LICENSE("GPL v2");