core.c

   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 (!ep->desc || usb_endpoint_maxp(ep->desc) == 0) {
 122		WARN_ONCE(1, "%s: ep%d (%s) has %s\n", __func__, ep->address, ep->name,
 123			  (!ep->desc) ? "NULL descriptor" : "maxpacket 0");
 124
 125		ret = -EINVAL;
 126		goto out;
 127	}
 128
 129	ret = ep->ops->enable(ep, ep->desc);
 130	if (ret)
 131		goto out;
 132
 133	ep->enabled = true;
 134
 135out:
 136	trace_usb_ep_enable(ep, ret);
 137
 138	return ret;
 139}
 140EXPORT_SYMBOL_GPL(usb_ep_enable);
 141
 142/**
 143 * usb_ep_disable - endpoint is no longer usable
 144 * @ep:the endpoint being unconfigured.  may not be the endpoint named "ep0".
 145 *
 146 * no other task may be using this endpoint when this is called.
 147 * any pending and uncompleted requests will complete with status
 148 * indicating disconnect (-ESHUTDOWN) before this call returns.
 149 * gadget drivers must call usb_ep_enable() again before queueing
 150 * requests to the endpoint.
 151 *
 152 * This routine may be called in an atomic (interrupt) context.
 153 *
 154 * returns zero, or a negative error code.
 155 */
 156int usb_ep_disable(struct usb_ep *ep)
 157{
 158	int ret = 0;
 159
 160	if (!ep->enabled)
 161		goto out;
 162
 163	ret = ep->ops->disable(ep);
 164	if (ret)
 165		goto out;
 166
 167	ep->enabled = false;
 168
 169out:
 170	trace_usb_ep_disable(ep, ret);
 171
 172	return ret;
 173}
 174EXPORT_SYMBOL_GPL(usb_ep_disable);
 175
 176/**
 177 * usb_ep_alloc_request - allocate a request object to use with this endpoint
 178 * @ep:the endpoint to be used with with the request
 179 * @gfp_flags:GFP_* flags to use
 180 *
 181 * Request objects must be allocated with this call, since they normally
 182 * need controller-specific setup and may even need endpoint-specific
 183 * resources such as allocation of DMA descriptors.
 184 * Requests may be submitted with usb_ep_queue(), and receive a single
 185 * completion callback.  Free requests with usb_ep_free_request(), when
 186 * they are no longer needed.
 187 *
 188 * Returns the request, or null if one could not be allocated.
 189 */
 190struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
 191						       gfp_t gfp_flags)
 192{
 193	struct usb_request *req = NULL;
 194
 195	req = ep->ops->alloc_request(ep, gfp_flags);
 196
 197	if (req)
 198		req->ep = ep;
 199
 200	trace_usb_ep_alloc_request(ep, req, req ? 0 : -ENOMEM);
 201
 202	return req;
 203}
 204EXPORT_SYMBOL_GPL(usb_ep_alloc_request);
 205
 206/**
 207 * usb_ep_free_request - frees a request object
 208 * @ep:the endpoint associated with the request
 209 * @req:the request being freed
 210 *
 211 * Reverses the effect of usb_ep_alloc_request().
 212 * Caller guarantees the request is not queued, and that it will
 213 * no longer be requeued (or otherwise used).
 214 */
 215void usb_ep_free_request(struct usb_ep *ep,
 216				       struct usb_request *req)
 217{
 218	trace_usb_ep_free_request(ep, req, 0);
 219	ep->ops->free_request(ep, req);
 220}
 221EXPORT_SYMBOL_GPL(usb_ep_free_request);
 222
 223/**
 224 * usb_ep_queue - queues (submits) an I/O request to an endpoint.
 225 * @ep:the endpoint associated with the request
 226 * @req:the request being submitted
 227 * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
 228 *	pre-allocate all necessary memory with the request.
 229 *
 230 * This tells the device controller to perform the specified request through
 231 * that endpoint (reading or writing a buffer).  When the request completes,
 232 * including being canceled by usb_ep_dequeue(), the request's completion
 233 * routine is called to return the request to the driver.  Any endpoint
 234 * (except control endpoints like ep0) may have more than one transfer
 235 * request queued; they complete in FIFO order.  Once a gadget driver
 236 * submits a request, that request may not be examined or modified until it
 237 * is given back to that driver through the completion callback.
 238 *
 239 * Each request is turned into one or more packets.  The controller driver
 240 * never merges adjacent requests into the same packet.  OUT transfers
 241 * will sometimes use data that's already buffered in the hardware.
 242 * Drivers can rely on the fact that the first byte of the request's buffer
 243 * always corresponds to the first byte of some USB packet, for both
 244 * IN and OUT transfers.
 245 *
 246 * Bulk endpoints can queue any amount of data; the transfer is packetized
 247 * automatically.  The last packet will be short if the request doesn't fill it
 248 * out completely.  Zero length packets (ZLPs) should be avoided in portable
 249 * protocols since not all usb hardware can successfully handle zero length
 250 * packets.  (ZLPs may be explicitly written, and may be implicitly written if
 251 * the request 'zero' flag is set.)  Bulk endpoints may also be used
 252 * for interrupt transfers; but the reverse is not true, and some endpoints
 253 * won't support every interrupt transfer.  (Such as 768 byte packets.)
 254 *
 255 * Interrupt-only endpoints are less functional than bulk endpoints, for
 256 * example by not supporting queueing or not handling buffers that are
 257 * larger than the endpoint's maxpacket size.  They may also treat data
 258 * toggle differently.
 259 *
 260 * Control endpoints ... after getting a setup() callback, the driver queues
 261 * one response (even if it would be zero length).  That enables the
 262 * status ack, after transferring data as specified in the response.  Setup
 263 * functions may return negative error codes to generate protocol stalls.
 264 * (Note that some USB device controllers disallow protocol stall responses
 265 * in some cases.)  When control responses are deferred (the response is
 266 * written after the setup callback returns), then usb_ep_set_halt() may be
 267 * used on ep0 to trigger protocol stalls.  Depending on the controller,
 268 * it may not be possible to trigger a status-stage protocol stall when the
 269 * data stage is over, that is, from within the response's completion
 270 * routine.
 271 *
 272 * For periodic endpoints, like interrupt or isochronous ones, the usb host
 273 * arranges to poll once per interval, and the gadget driver usually will
 274 * have queued some data to transfer at that time.
 275 *
 276 * Note that @req's ->complete() callback must never be called from
 277 * within usb_ep_queue() as that can create deadlock situations.
 278 *
 279 * This routine may be called in interrupt context.
 280 *
 281 * Returns zero, or a negative error code.  Endpoints that are not enabled
 282 * report errors; errors will also be
 283 * reported when the usb peripheral is disconnected.
 284 *
 285 * If and only if @req is successfully queued (the return value is zero),
 286 * @req->complete() will be called exactly once, when the Gadget core and
 287 * UDC are finished with the request.  When the completion function is called,
 288 * control of the request is returned to the device driver which submitted it.
 289 * The completion handler may then immediately free or reuse @req.
 290 */
 291int usb_ep_queue(struct usb_ep *ep,
 292			       struct usb_request *req, gfp_t gfp_flags)
 293{
 294	int ret = 0;
 295
 296	if (!ep->enabled && ep->address) {
 297		pr_debug("USB gadget: queue request to disabled ep 0x%x (%s)\n",
 298				 ep->address, ep->name);
 299		ret = -ESHUTDOWN;
 300		goto out;
 301	}
 302
 303	ret = ep->ops->queue(ep, req, gfp_flags);
 304
 305out:
 306	trace_usb_ep_queue(ep, req, ret);
 307
 308	return ret;
 309}
 310EXPORT_SYMBOL_GPL(usb_ep_queue);
 311
 312/**
 313 * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
 314 * @ep:the endpoint associated with the request
 315 * @req:the request being canceled
 316 *
 317 * If the request is still active on the endpoint, it is dequeued and
 318 * eventually its completion routine is called (with status -ECONNRESET);
 319 * else a negative error code is returned.  This routine is asynchronous,
 320 * that is, it may return before the completion routine runs.
 321 *
 322 * Note that some hardware can't clear out write fifos (to unlink the request
 323 * at the head of the queue) except as part of disconnecting from usb. Such
 324 * restrictions prevent drivers from supporting configuration changes,
 325 * even to configuration zero (a "chapter 9" requirement).
 326 *
 327 * This routine may be called in interrupt context.
 328 */
 329int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
 330{
 331	int ret;
 332
 333	ret = ep->ops->dequeue(ep, req);
 334	trace_usb_ep_dequeue(ep, req, ret);
 335
 336	return ret;
 337}
 338EXPORT_SYMBOL_GPL(usb_ep_dequeue);
 339
 340/**
 341 * usb_ep_set_halt - sets the endpoint halt feature.
 342 * @ep: the non-isochronous endpoint being stalled
 343 *
 344 * Use this to stall an endpoint, perhaps as an error report.
 345 * Except for control endpoints,
 346 * the endpoint stays halted (will not stream any data) until the host
 347 * clears this feature; drivers may need to empty the endpoint's request
 348 * queue first, to make sure no inappropriate transfers happen.
 349 *
 350 * Note that while an endpoint CLEAR_FEATURE will be invisible to the
 351 * gadget driver, a SET_INTERFACE will not be.  To reset endpoints for the
 352 * current altsetting, see usb_ep_clear_halt().  When switching altsettings,
 353 * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
 354 *
 355 * This routine may be called in interrupt context.
 356 *
 357 * Returns zero, or a negative error code.  On success, this call sets
 358 * underlying hardware state that blocks data transfers.
 359 * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
 360 * transfer requests are still queued, or if the controller hardware
 361 * (usually a FIFO) still holds bytes that the host hasn't collected.
 362 */
 363int usb_ep_set_halt(struct usb_ep *ep)
 364{
 365	int ret;
 366
 367	ret = ep->ops->set_halt(ep, 1);
 368	trace_usb_ep_set_halt(ep, ret);
 369
 370	return ret;
 371}
 372EXPORT_SYMBOL_GPL(usb_ep_set_halt);
 373
 374/**
 375 * usb_ep_clear_halt - clears endpoint halt, and resets toggle
 376 * @ep:the bulk or interrupt endpoint being reset
 377 *
 378 * Use this when responding to the standard usb "set interface" request,
 379 * for endpoints that aren't reconfigured, after clearing any other state
 380 * in the endpoint's i/o queue.
 381 *
 382 * This routine may be called in interrupt context.
 383 *
 384 * Returns zero, or a negative error code.  On success, this call clears
 385 * the underlying hardware state reflecting endpoint halt and data toggle.
 386 * Note that some hardware can't support this request (like pxa2xx_udc),
 387 * and accordingly can't correctly implement interface altsettings.
 388 */
 389int usb_ep_clear_halt(struct usb_ep *ep)
 390{
 391	int ret;
 392
 393	ret = ep->ops->set_halt(ep, 0);
 394	trace_usb_ep_clear_halt(ep, ret);
 395
 396	return ret;
 397}
 398EXPORT_SYMBOL_GPL(usb_ep_clear_halt);
 399
 400/**
 401 * usb_ep_set_wedge - sets the halt feature and ignores clear requests
 402 * @ep: the endpoint being wedged
 403 *
 404 * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT)
 405 * requests. If the gadget driver clears the halt status, it will
 406 * automatically unwedge the endpoint.
 407 *
 408 * This routine may be called in interrupt context.
 409 *
 410 * Returns zero on success, else negative errno.
 411 */
 412int usb_ep_set_wedge(struct usb_ep *ep)
 413{
 414	int ret;
 415
 416	if (ep->ops->set_wedge)
 417		ret = ep->ops->set_wedge(ep);
 418	else
 419		ret = ep->ops->set_halt(ep, 1);
 420
 421	trace_usb_ep_set_wedge(ep, ret);
 422
 423	return ret;
 424}
 425EXPORT_SYMBOL_GPL(usb_ep_set_wedge);
 426
 427/**
 428 * usb_ep_fifo_status - returns number of bytes in fifo, or error
 429 * @ep: the endpoint whose fifo status is being checked.
 430 *
 431 * FIFO endpoints may have "unclaimed data" in them in certain cases,
 432 * such as after aborted transfers.  Hosts may not have collected all
 433 * the IN data written by the gadget driver (and reported by a request
 434 * completion).  The gadget driver may not have collected all the data
 435 * written OUT to it by the host.  Drivers that need precise handling for
 436 * fault reporting or recovery may need to use this call.
 437 *
 438 * This routine may be called in interrupt context.
 439 *
 440 * This returns the number of such bytes in the fifo, or a negative
 441 * errno if the endpoint doesn't use a FIFO or doesn't support such
 442 * precise handling.
 443 */
 444int usb_ep_fifo_status(struct usb_ep *ep)
 445{
 446	int ret;
 447
 448	if (ep->ops->fifo_status)
 449		ret = ep->ops->fifo_status(ep);
 450	else
 451		ret = -EOPNOTSUPP;
 452
 453	trace_usb_ep_fifo_status(ep, ret);
 454
 455	return ret;
 456}
 457EXPORT_SYMBOL_GPL(usb_ep_fifo_status);
 458
 459/**
 460 * usb_ep_fifo_flush - flushes contents of a fifo
 461 * @ep: the endpoint whose fifo is being flushed.
 462 *
 463 * This call may be used to flush the "unclaimed data" that may exist in
 464 * an endpoint fifo after abnormal transaction terminations.  The call
 465 * must never be used except when endpoint is not being used for any
 466 * protocol translation.
 467 *
 468 * This routine may be called in interrupt context.
 469 */
 470void usb_ep_fifo_flush(struct usb_ep *ep)
 471{
 472	if (ep->ops->fifo_flush)
 473		ep->ops->fifo_flush(ep);
 474
 475	trace_usb_ep_fifo_flush(ep, 0);
 476}
 477EXPORT_SYMBOL_GPL(usb_ep_fifo_flush);
 478
 479/* ------------------------------------------------------------------------- */
 480
 481/**
 482 * usb_gadget_frame_number - returns the current frame number
 483 * @gadget: controller that reports the frame number
 484 *
 485 * Returns the usb frame number, normally eleven bits from a SOF packet,
 486 * or negative errno if this device doesn't support this capability.
 487 */
 488int usb_gadget_frame_number(struct usb_gadget *gadget)
 489{
 490	int ret;
 491
 492	ret = gadget->ops->get_frame(gadget);
 493
 494	trace_usb_gadget_frame_number(gadget, ret);
 495
 496	return ret;
 497}
 498EXPORT_SYMBOL_GPL(usb_gadget_frame_number);
 499
 500/**
 501 * usb_gadget_wakeup - tries to wake up the host connected to this gadget
 502 * @gadget: controller used to wake up the host
 503 *
 504 * Returns zero on success, else negative error code if the hardware
 505 * doesn't support such attempts, or its support has not been enabled
 506 * by the usb host.  Drivers must return device descriptors that report
 507 * their ability to support this, or hosts won't enable it.
 508 *
 509 * This may also try to use SRP to wake the host and start enumeration,
 510 * even if OTG isn't otherwise in use.  OTG devices may also start
 511 * remote wakeup even when hosts don't explicitly enable it.
 512 */
 513int usb_gadget_wakeup(struct usb_gadget *gadget)
 514{
 515	int ret = 0;
 516
 517	if (!gadget->ops->wakeup) {
 518		ret = -EOPNOTSUPP;
 519		goto out;
 520	}
 521
 522	ret = gadget->ops->wakeup(gadget);
 523
 524out:
 525	trace_usb_gadget_wakeup(gadget, ret);
 526
 527	return ret;
 528}
 529EXPORT_SYMBOL_GPL(usb_gadget_wakeup);
 530
 531/**
 532 * usb_gadget_set_remote_wakeup - configures the device remote wakeup feature.
 533 * @gadget:the device being configured for remote wakeup
 534 * @set:value to be configured.
 535 *
 536 * set to one to enable remote wakeup feature and zero to disable it.
 537 *
 538 * returns zero on success, else negative errno.
 539 */
 540int usb_gadget_set_remote_wakeup(struct usb_gadget *gadget, int set)
 541{
 542	int ret = 0;
 543
 544	if (!gadget->ops->set_remote_wakeup) {
 545		ret = -EOPNOTSUPP;
 546		goto out;
 547	}
 548
 549	ret = gadget->ops->set_remote_wakeup(gadget, set);
 550
 551out:
 552	trace_usb_gadget_set_remote_wakeup(gadget, ret);
 553
 554	return ret;
 555}
 556EXPORT_SYMBOL_GPL(usb_gadget_set_remote_wakeup);
 557
 558/**
 559 * usb_gadget_set_selfpowered - sets the device selfpowered feature.
 560 * @gadget:the device being declared as self-powered
 561 *
 562 * this affects the device status reported by the hardware driver
 563 * to reflect that it now has a local power supply.
 564 *
 565 * returns zero on success, else negative errno.
 566 */
 567int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
 568{
 569	int ret = 0;
 570
 571	if (!gadget->ops->set_selfpowered) {
 572		ret = -EOPNOTSUPP;
 573		goto out;
 574	}
 575
 576	ret = gadget->ops->set_selfpowered(gadget, 1);
 577
 578out:
 579	trace_usb_gadget_set_selfpowered(gadget, ret);
 580
 581	return ret;
 582}
 583EXPORT_SYMBOL_GPL(usb_gadget_set_selfpowered);
 584
 585/**
 586 * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
 587 * @gadget:the device being declared as bus-powered
 588 *
 589 * this affects the device status reported by the hardware driver.
 590 * some hardware may not support bus-powered operation, in which
 591 * case this feature's value can never change.
 592 *
 593 * returns zero on success, else negative errno.
 594 */
 595int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
 596{
 597	int ret = 0;
 598
 599	if (!gadget->ops->set_selfpowered) {
 600		ret = -EOPNOTSUPP;
 601		goto out;
 602	}
 603
 604	ret = gadget->ops->set_selfpowered(gadget, 0);
 605
 606out:
 607	trace_usb_gadget_clear_selfpowered(gadget, ret);
 608
 609	return ret;
 610}
 611EXPORT_SYMBOL_GPL(usb_gadget_clear_selfpowered);
 612
 613/**
 614 * usb_gadget_vbus_connect - Notify controller that VBUS is powered
 615 * @gadget:The device which now has VBUS power.
 616 * Context: can sleep
 617 *
 618 * This call is used by a driver for an external transceiver (or GPIO)
 619 * that detects a VBUS power session starting.  Common responses include
 620 * resuming the controller, activating the D+ (or D-) pullup to let the
 621 * host detect that a USB device is attached, and starting to draw power
 622 * (8mA or possibly more, especially after SET_CONFIGURATION).
 623 *
 624 * Returns zero on success, else negative errno.
 625 */
 626int usb_gadget_vbus_connect(struct usb_gadget *gadget)
 627{
 628	int ret = 0;
 629
 630	if (!gadget->ops->vbus_session) {
 631		ret = -EOPNOTSUPP;
 632		goto out;
 633	}
 634
 635	ret = gadget->ops->vbus_session(gadget, 1);
 636
 637out:
 638	trace_usb_gadget_vbus_connect(gadget, ret);
 639
 640	return ret;
 641}
 642EXPORT_SYMBOL_GPL(usb_gadget_vbus_connect);
 643
 644/**
 645 * usb_gadget_vbus_draw - constrain controller's VBUS power usage
 646 * @gadget:The device whose VBUS usage is being described
 647 * @mA:How much current to draw, in milliAmperes.  This should be twice
 648 *	the value listed in the configuration descriptor bMaxPower field.
 649 *
 650 * This call is used by gadget drivers during SET_CONFIGURATION calls,
 651 * reporting how much power the device may consume.  For example, this
 652 * could affect how quickly batteries are recharged.
 653 *
 654 * Returns zero on success, else negative errno.
 655 */
 656int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
 657{
 658	int ret = 0;
 659
 660	if (!gadget->ops->vbus_draw) {
 661		ret = -EOPNOTSUPP;
 662		goto out;
 663	}
 664
 665	ret = gadget->ops->vbus_draw(gadget, mA);
 666	if (!ret)
 667		gadget->mA = mA;
 668
 669out:
 670	trace_usb_gadget_vbus_draw(gadget, ret);
 671
 672	return ret;
 673}
 674EXPORT_SYMBOL_GPL(usb_gadget_vbus_draw);
 675
 676/**
 677 * usb_gadget_vbus_disconnect - notify controller about VBUS session end
 678 * @gadget:the device whose VBUS supply is being described
 679 * Context: can sleep
 680 *
 681 * This call is used by a driver for an external transceiver (or GPIO)
 682 * that detects a VBUS power session ending.  Common responses include
 683 * reversing everything done in usb_gadget_vbus_connect().
 684 *
 685 * Returns zero on success, else negative errno.
 686 */
 687int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
 688{
 689	int ret = 0;
 690
 691	if (!gadget->ops->vbus_session) {
 692		ret = -EOPNOTSUPP;
 693		goto out;
 694	}
 695
 696	ret = gadget->ops->vbus_session(gadget, 0);
 697
 698out:
 699	trace_usb_gadget_vbus_disconnect(gadget, ret);
 700
 701	return ret;
 702}
 703EXPORT_SYMBOL_GPL(usb_gadget_vbus_disconnect);
 704
 705static int usb_gadget_connect_locked(struct usb_gadget *gadget)
 706	__must_hold(&gadget->udc->connect_lock)
 707{
 708	int ret = 0;
 709
 710	if (!gadget->ops->pullup) {
 711		ret = -EOPNOTSUPP;
 712		goto out;
 713	}
 714
 715	if (gadget->deactivated || !gadget->udc->allow_connect || !gadget->udc->started) {
 716		/*
 717		 * If the gadget isn't usable (because it is deactivated,
 718		 * unbound, or not yet started), we only save the new state.
 719		 * The gadget will be connected automatically when it is
 720		 * activated/bound/started.
 721		 */
 722		gadget->connected = true;
 723		goto out;
 724	}
 725
 726	ret = gadget->ops->pullup(gadget, 1);
 727	if (!ret)
 728		gadget->connected = 1;
 729
 730out:
 731	trace_usb_gadget_connect(gadget, ret);
 732
 733	return ret;
 734}
 735
 736/**
 737 * usb_gadget_connect - software-controlled connect to USB host
 738 * @gadget:the peripheral being connected
 739 *
 740 * Enables the D+ (or potentially D-) pullup.  The host will start
 741 * enumerating this gadget when the pullup is active and a VBUS session
 742 * is active (the link is powered).
 743 *
 744 * Returns zero on success, else negative errno.
 745 */
 746int usb_gadget_connect(struct usb_gadget *gadget)
 747{
 748	int ret;
 749
 750	mutex_lock(&gadget->udc->connect_lock);
 751	ret = usb_gadget_connect_locked(gadget);
 752	mutex_unlock(&gadget->udc->connect_lock);
 753
 754	return ret;
 755}
 756EXPORT_SYMBOL_GPL(usb_gadget_connect);
 757
 758static int usb_gadget_disconnect_locked(struct usb_gadget *gadget)
 759	__must_hold(&gadget->udc->connect_lock)
 760{
 761	int ret = 0;
 762
 763	if (!gadget->ops->pullup) {
 764		ret = -EOPNOTSUPP;
 765		goto out;
 766	}
 767
 768	if (!gadget->connected)
 769		goto out;
 770
 771	if (gadget->deactivated || !gadget->udc->started) {
 772		/*
 773		 * If gadget is deactivated we only save new state.
 774		 * Gadget will stay disconnected after activation.
 775		 */
 776		gadget->connected = false;
 777		goto out;
 778	}
 779
 780	ret = gadget->ops->pullup(gadget, 0);
 781	if (!ret)
 782		gadget->connected = 0;
 783
 784	mutex_lock(&udc_lock);
 785	if (gadget->udc->driver)
 786		gadget->udc->driver->disconnect(gadget);
 787	mutex_unlock(&udc_lock);
 788
 789out:
 790	trace_usb_gadget_disconnect(gadget, ret);
 791
 792	return ret;
 793}
 794
 795/**
 796 * usb_gadget_disconnect - software-controlled disconnect from USB host
 797 * @gadget:the peripheral being disconnected
 798 *
 799 * Disables the D+ (or potentially D-) pullup, which the host may see
 800 * as a disconnect (when a VBUS session is active).  Not all systems
 801 * support software pullup controls.
 802 *
 803 * Following a successful disconnect, invoke the ->disconnect() callback
 804 * for the current gadget driver so that UDC drivers don't need to.
 805 *
 806 * Returns zero on success, else negative errno.
 807 */
 808int usb_gadget_disconnect(struct usb_gadget *gadget)
 809{
 810	int ret;
 811
 812	mutex_lock(&gadget->udc->connect_lock);
 813	ret = usb_gadget_disconnect_locked(gadget);
 814	mutex_unlock(&gadget->udc->connect_lock);
 815
 816	return ret;
 817}
 818EXPORT_SYMBOL_GPL(usb_gadget_disconnect);
 819
 820/**
 821 * usb_gadget_deactivate - deactivate function which is not ready to work
 822 * @gadget: the peripheral being deactivated
 823 *
 824 * This routine may be used during the gadget driver bind() call to prevent
 825 * the peripheral from ever being visible to the USB host, unless later
 826 * usb_gadget_activate() is called.  For example, user mode components may
 827 * need to be activated before the system can talk to hosts.
 828 *
 829 * This routine may sleep; it must not be called in interrupt context
 830 * (such as from within a gadget driver's disconnect() callback).
 831 *
 832 * Returns zero on success, else negative errno.
 833 */
 834int usb_gadget_deactivate(struct usb_gadget *gadget)
 835{
 836	int ret = 0;
 837
 838	mutex_lock(&gadget->udc->connect_lock);
 839	if (gadget->deactivated)
 840		goto unlock;
 841
 842	if (gadget->connected) {
 843		ret = usb_gadget_disconnect_locked(gadget);
 844		if (ret)
 845			goto unlock;
 846
 847		/*
 848		 * If gadget was being connected before deactivation, we want
 849		 * to reconnect it in usb_gadget_activate().
 850		 */
 851		gadget->connected = true;
 852	}
 853	gadget->deactivated = true;
 854
 855unlock:
 856	mutex_unlock(&gadget->udc->connect_lock);
 857	trace_usb_gadget_deactivate(gadget, ret);
 858
 859	return ret;
 860}
 861EXPORT_SYMBOL_GPL(usb_gadget_deactivate);
 862
 863/**
 864 * usb_gadget_activate - activate function which is not ready to work
 865 * @gadget: the peripheral being activated
 866 *
 867 * This routine activates gadget which was previously deactivated with
 868 * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed.
 869 *
 870 * This routine may sleep; it must not be called in interrupt context.
 871 *
 872 * Returns zero on success, else negative errno.
 873 */
 874int usb_gadget_activate(struct usb_gadget *gadget)
 875{
 876	int ret = 0;
 877
 878	mutex_lock(&gadget->udc->connect_lock);
 879	if (!gadget->deactivated)
 880		goto unlock;
 881
 882	gadget->deactivated = false;
 883
 884	/*
 885	 * If gadget has been connected before deactivation, or became connected
 886	 * while it was being deactivated, we call usb_gadget_connect().
 887	 */
 888	if (gadget->connected)
 889		ret = usb_gadget_connect_locked(gadget);
 890
 891unlock:
 892	mutex_unlock(&gadget->udc->connect_lock);
 893	trace_usb_gadget_activate(gadget, ret);
 894
 895	return ret;
 896}
 897EXPORT_SYMBOL_GPL(usb_gadget_activate);
 898
 899/* ------------------------------------------------------------------------- */
 900
 901#ifdef	CONFIG_HAS_DMA
 902
 903int usb_gadget_map_request_by_dev(struct device *dev,
 904		struct usb_request *req, int is_in)
 905{
 906	if (req->length == 0)
 907		return 0;
 908
 909	if (req->sg_was_mapped) {
 910		req->num_mapped_sgs = req->num_sgs;
 911		return 0;
 912	}
 913
 914	if (req->num_sgs) {
 915		int     mapped;
 916
 917		mapped = dma_map_sg(dev, req->sg, req->num_sgs,
 918				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 919		if (mapped == 0) {
 920			dev_err(dev, "failed to map SGs\n");
 921			return -EFAULT;
 922		}
 923
 924		req->num_mapped_sgs = mapped;
 925	} else {
 926		if (is_vmalloc_addr(req->buf)) {
 927			dev_err(dev, "buffer is not dma capable\n");
 928			return -EFAULT;
 929		} else if (object_is_on_stack(req->buf)) {
 930			dev_err(dev, "buffer is on stack\n");
 931			return -EFAULT;
 932		}
 933
 934		req->dma = dma_map_single(dev, req->buf, req->length,
 935				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 936
 937		if (dma_mapping_error(dev, req->dma)) {
 938			dev_err(dev, "failed to map buffer\n");
 939			return -EFAULT;
 940		}
 941
 942		req->dma_mapped = 1;
 943	}
 944
 945	return 0;
 946}
 947EXPORT_SYMBOL_GPL(usb_gadget_map_request_by_dev);
 948
 949int usb_gadget_map_request(struct usb_gadget *gadget,
 950		struct usb_request *req, int is_in)
 951{
 952	return usb_gadget_map_request_by_dev(gadget->dev.parent, req, is_in);
 953}
 954EXPORT_SYMBOL_GPL(usb_gadget_map_request);
 955
 956void usb_gadget_unmap_request_by_dev(struct device *dev,
 957		struct usb_request *req, int is_in)
 958{
 959	if (req->length == 0 || req->sg_was_mapped)
 960		return;
 961
 962	if (req->num_mapped_sgs) {
 963		dma_unmap_sg(dev, req->sg, req->num_sgs,
 964				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 965
 966		req->num_mapped_sgs = 0;
 967	} else if (req->dma_mapped) {
 968		dma_unmap_single(dev, req->dma, req->length,
 969				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 970		req->dma_mapped = 0;
 971	}
 972}
 973EXPORT_SYMBOL_GPL(usb_gadget_unmap_request_by_dev);
 974
 975void usb_gadget_unmap_request(struct usb_gadget *gadget,
 976		struct usb_request *req, int is_in)
 977{
 978	usb_gadget_unmap_request_by_dev(gadget->dev.parent, req, is_in);
 979}
 980EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);
 981
 982#endif	/* CONFIG_HAS_DMA */
 983
 984/* ------------------------------------------------------------------------- */
 985
 986/**
 987 * usb_gadget_giveback_request - give the request back to the gadget layer
 988 * @ep: the endpoint to be used with with the request
 989 * @req: the request being given back
 990 *
 991 * This is called by device controller drivers in order to return the
 992 * completed request back to the gadget layer.
 993 */
 994void usb_gadget_giveback_request(struct usb_ep *ep,
 995		struct usb_request *req)
 996{
 997	if (likely(req->status == 0))
 998		usb_led_activity(USB_LED_EVENT_GADGET);
 999
1000	trace_usb_gadget_giveback_request(ep, req, 0);
1001
1002	req->complete(ep, req);
1003}
1004EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
1005
1006/* ------------------------------------------------------------------------- */
1007
1008/**
1009 * gadget_find_ep_by_name - returns ep whose name is the same as sting passed
1010 *	in second parameter or NULL if searched endpoint not found
1011 * @g: controller to check for quirk
1012 * @name: name of searched endpoint
1013 */
1014struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g, const char *name)
1015{
1016	struct usb_ep *ep;
1017
1018	gadget_for_each_ep(ep, g) {
1019		if (!strcmp(ep->name, name))
1020			return ep;
1021	}
1022
1023	return NULL;
1024}
1025EXPORT_SYMBOL_GPL(gadget_find_ep_by_name);
1026
1027/* ------------------------------------------------------------------------- */
1028
1029int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
1030		struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
1031		struct usb_ss_ep_comp_descriptor *ep_comp)
1032{
1033	u8		type;
1034	u16		max;
1035	int		num_req_streams = 0;
1036
1037	/* endpoint already claimed? */
1038	if (ep->claimed)
1039		return 0;
1040
1041	type = usb_endpoint_type(desc);
1042	max = usb_endpoint_maxp(desc);
1043
1044	if (usb_endpoint_dir_in(desc) && !ep->caps.dir_in)
1045		return 0;
1046	if (usb_endpoint_dir_out(desc) && !ep->caps.dir_out)
1047		return 0;
1048
1049	if (max > ep->maxpacket_limit)
1050		return 0;
1051
1052	/* "high bandwidth" works only at high speed */
1053	if (!gadget_is_dualspeed(gadget) && usb_endpoint_maxp_mult(desc) > 1)
1054		return 0;
1055
1056	switch (type) {
1057	case USB_ENDPOINT_XFER_CONTROL:
1058		/* only support ep0 for portable CONTROL traffic */
1059		return 0;
1060	case USB_ENDPOINT_XFER_ISOC:
1061		if (!ep->caps.type_iso)
1062			return 0;
1063		/* ISO:  limit 1023 bytes full speed, 1024 high/super speed */
1064		if (!gadget_is_dualspeed(gadget) && max > 1023)
1065			return 0;
1066		break;
1067	case USB_ENDPOINT_XFER_BULK:
1068		if (!ep->caps.type_bulk)
1069			return 0;
1070		if (ep_comp && gadget_is_superspeed(gadget)) {
1071			/* Get the number of required streams from the
1072			 * EP companion descriptor and see if the EP
1073			 * matches it
1074			 */
1075			num_req_streams = ep_comp->bmAttributes & 0x1f;
1076			if (num_req_streams > ep->max_streams)
1077				return 0;
1078		}
1079		break;
1080	case USB_ENDPOINT_XFER_INT:
1081		/* Bulk endpoints handle interrupt transfers,
1082		 * except the toggle-quirky iso-synch kind
1083		 */
1084		if (!ep->caps.type_int && !ep->caps.type_bulk)
1085			return 0;
1086		/* INT:  limit 64 bytes full speed, 1024 high/super speed */
1087		if (!gadget_is_dualspeed(gadget) && max > 64)
1088			return 0;
1089		break;
1090	}
1091
1092	return 1;
1093}
1094EXPORT_SYMBOL_GPL(usb_gadget_ep_match_desc);
1095
1096/**
1097 * usb_gadget_check_config - checks if the UDC can support the binded
1098 *	configuration
1099 * @gadget: controller to check the USB configuration
1100 *
1101 * Ensure that a UDC is able to support the requested resources by a
1102 * configuration, and that there are no resource limitations, such as
1103 * internal memory allocated to all requested endpoints.
1104 *
1105 * Returns zero on success, else a negative errno.
1106 */
1107int usb_gadget_check_config(struct usb_gadget *gadget)
1108{
1109	if (gadget->ops->check_config)
1110		return gadget->ops->check_config(gadget);
1111	return 0;
1112}
1113EXPORT_SYMBOL_GPL(usb_gadget_check_config);
1114
1115/* ------------------------------------------------------------------------- */
1116
1117static void usb_gadget_state_work(struct work_struct *work)
1118{
1119	struct usb_gadget *gadget = work_to_gadget(work);
1120	struct usb_udc *udc = gadget->udc;
1121
1122	if (udc)
1123		sysfs_notify(&udc->dev.kobj, NULL, "state");
1124}
1125
1126void usb_gadget_set_state(struct usb_gadget *gadget,
1127		enum usb_device_state state)
1128{
1129	unsigned long flags;
1130
1131	spin_lock_irqsave(&gadget->state_lock, flags);
1132	gadget->state = state;
1133	if (!gadget->teardown)
1134		schedule_work(&gadget->work);
1135	spin_unlock_irqrestore(&gadget->state_lock, flags);
1136	trace_usb_gadget_set_state(gadget, 0);
1137}
1138EXPORT_SYMBOL_GPL(usb_gadget_set_state);
1139
1140/* ------------------------------------------------------------------------- */
1141
1142/* Acquire connect_lock before calling this function. */
1143static int usb_udc_connect_control_locked(struct usb_udc *udc) __must_hold(&udc->connect_lock)
1144{
1145	if (udc->vbus)
1146		return usb_gadget_connect_locked(udc->gadget);
1147	else
1148		return usb_gadget_disconnect_locked(udc->gadget);
1149}
1150
1151static void vbus_event_work(struct work_struct *work)
1152{
1153	struct usb_udc *udc = container_of(work, struct usb_udc, vbus_work);
1154
1155	mutex_lock(&udc->connect_lock);
1156	usb_udc_connect_control_locked(udc);
1157	mutex_unlock(&udc->connect_lock);
1158}
1159
1160/**
1161 * usb_udc_vbus_handler - updates the udc core vbus status, and try to
1162 * connect or disconnect gadget
1163 * @gadget: The gadget which vbus change occurs
1164 * @status: The vbus status
1165 *
1166 * The udc driver calls it when it wants to connect or disconnect gadget
1167 * according to vbus status.
1168 *
1169 * This function can be invoked from interrupt context by irq handlers of
1170 * the gadget drivers, however, usb_udc_connect_control() has to run in
1171 * non-atomic context due to the following:
1172 * a. Some of the gadget driver implementations expect the ->pullup
1173 * callback to be invoked in non-atomic context.
1174 * b. usb_gadget_disconnect() acquires udc_lock which is a mutex.
1175 * Hence offload invocation of usb_udc_connect_control() to workqueue.
1176 */
1177void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status)
1178{
1179	struct usb_udc *udc = gadget->udc;
1180
1181	if (udc) {
1182		udc->vbus = status;
1183		schedule_work(&udc->vbus_work);
1184	}
1185}
1186EXPORT_SYMBOL_GPL(usb_udc_vbus_handler);
1187
1188/**
1189 * usb_gadget_udc_reset - notifies the udc core that bus reset occurs
1190 * @gadget: The gadget which bus reset occurs
1191 * @driver: The gadget driver we want to notify
1192 *
1193 * If the udc driver has bus reset handler, it needs to call this when the bus
1194 * reset occurs, it notifies the gadget driver that the bus reset occurs as
1195 * well as updates gadget state.
1196 */
1197void usb_gadget_udc_reset(struct usb_gadget *gadget,
1198		struct usb_gadget_driver *driver)
1199{
1200	driver->reset(gadget);
1201	usb_gadget_set_state(gadget, USB_STATE_DEFAULT);
1202}
1203EXPORT_SYMBOL_GPL(usb_gadget_udc_reset);
1204
1205/**
1206 * usb_gadget_udc_start_locked - tells usb device controller to start up
1207 * @udc: The UDC to be started
1208 *
1209 * This call is issued by the UDC Class driver when it's about
1210 * to register a gadget driver to the device controller, before
1211 * calling gadget driver's bind() method.
1212 *
1213 * It allows the controller to be powered off until strictly
1214 * necessary to have it powered on.
1215 *
1216 * Returns zero on success, else negative errno.
1217 *
1218 * Caller should acquire connect_lock before invoking this function.
1219 */
1220static inline int usb_gadget_udc_start_locked(struct usb_udc *udc)
1221	__must_hold(&udc->connect_lock)
1222{
1223	int ret;
1224
1225	if (udc->started) {
1226		dev_err(&udc->dev, "UDC had already started\n");
1227		return -EBUSY;
1228	}
1229
1230	ret = udc->gadget->ops->udc_start(udc->gadget, udc->driver);
1231	if (!ret)
1232		udc->started = true;
1233
1234	return ret;
1235}
1236
1237/**
1238 * usb_gadget_udc_stop_locked - tells usb device controller we don't need it anymore
1239 * @udc: The UDC to be stopped
1240 *
1241 * This call is issued by the UDC Class driver after calling
1242 * gadget driver's unbind() method.
1243 *
1244 * The details are implementation specific, but it can go as
1245 * far as powering off UDC completely and disable its data
1246 * line pullups.
1247 *
1248 * Caller should acquire connect lock before invoking this function.
1249 */
1250static inline void usb_gadget_udc_stop_locked(struct usb_udc *udc)
1251	__must_hold(&udc->connect_lock)
1252{
1253	if (!udc->started) {
1254		dev_err(&udc->dev, "UDC had already stopped\n");
1255		return;
1256	}
1257
1258	udc->gadget->ops->udc_stop(udc->gadget);
1259	udc->started = false;
1260}
1261
1262/**
1263 * usb_gadget_udc_set_speed - tells usb device controller speed supported by
1264 *    current driver
1265 * @udc: The device we want to set maximum speed
1266 * @speed: The maximum speed to allowed to run
1267 *
1268 * This call is issued by the UDC Class driver before calling
1269 * usb_gadget_udc_start() in order to make sure that we don't try to
1270 * connect on speeds the gadget driver doesn't support.
1271 */
1272static inline void usb_gadget_udc_set_speed(struct usb_udc *udc,
1273					    enum usb_device_speed speed)
1274{
1275	struct usb_gadget *gadget = udc->gadget;
1276	enum usb_device_speed s;
1277
1278	if (speed == USB_SPEED_UNKNOWN)
1279		s = gadget->max_speed;
1280	else
1281		s = min(speed, gadget->max_speed);
1282
1283	if (s == USB_SPEED_SUPER_PLUS && gadget->ops->udc_set_ssp_rate)
1284		gadget->ops->udc_set_ssp_rate(gadget, gadget->max_ssp_rate);
1285	else if (gadget->ops->udc_set_speed)
1286		gadget->ops->udc_set_speed(gadget, s);
1287}
1288
1289/**
1290 * usb_gadget_enable_async_callbacks - tell usb device controller to enable asynchronous callbacks
1291 * @udc: The UDC which should enable async callbacks
1292 *
1293 * This routine is used when binding gadget drivers.  It undoes the effect
1294 * of usb_gadget_disable_async_callbacks(); the UDC driver should enable IRQs
1295 * (if necessary) and resume issuing callbacks.
1296 *
1297 * This routine will always be called in process context.
1298 */
1299static inline void usb_gadget_enable_async_callbacks(struct usb_udc *udc)
1300{
1301	struct usb_gadget *gadget = udc->gadget;
1302
1303	if (gadget->ops->udc_async_callbacks)
1304		gadget->ops->udc_async_callbacks(gadget, true);
1305}
1306
1307/**
1308 * usb_gadget_disable_async_callbacks - tell usb device controller to disable asynchronous callbacks
1309 * @udc: The UDC which should disable async callbacks
1310 *
1311 * This routine is used when unbinding gadget drivers.  It prevents a race:
1312 * The UDC driver doesn't know when the gadget driver's ->unbind callback
1313 * runs, so unless it is told to disable asynchronous callbacks, it might
1314 * issue a callback (such as ->disconnect) after the unbind has completed.
1315 *
1316 * After this function runs, the UDC driver must suppress all ->suspend,
1317 * ->resume, ->disconnect, ->reset, and ->setup callbacks to the gadget driver
1318 * until async callbacks are again enabled.  A simple-minded but effective
1319 * way to accomplish this is to tell the UDC hardware not to generate any
1320 * more IRQs.
1321 *
1322 * Request completion callbacks must still be issued.  However, it's okay
1323 * to defer them until the request is cancelled, since the pull-up will be
1324 * turned off during the time period when async callbacks are disabled.
1325 *
1326 * This routine will always be called in process context.
1327 */
1328static inline void usb_gadget_disable_async_callbacks(struct usb_udc *udc)
1329{
1330	struct usb_gadget *gadget = udc->gadget;
1331
1332	if (gadget->ops->udc_async_callbacks)
1333		gadget->ops->udc_async_callbacks(gadget, false);
1334}
1335
1336/**
1337 * usb_udc_release - release the usb_udc struct
1338 * @dev: the dev member within usb_udc
1339 *
1340 * This is called by driver's core in order to free memory once the last
1341 * reference is released.
1342 */
1343static void usb_udc_release(struct device *dev)
1344{
1345	struct usb_udc *udc;
1346
1347	udc = container_of(dev, struct usb_udc, dev);
1348	dev_dbg(dev, "releasing '%s'\n", dev_name(dev));
1349	kfree(udc);
1350}
1351
1352static const struct attribute_group *usb_udc_attr_groups[];
1353
1354static void usb_udc_nop_release(struct device *dev)
1355{
1356	dev_vdbg(dev, "%s\n", __func__);
1357}
1358
1359/**
1360 * usb_initialize_gadget - initialize a gadget and its embedded struct device
1361 * @parent: the parent device to this udc. Usually the controller driver's
1362 * device.
1363 * @gadget: the gadget to be initialized.
1364 * @release: a gadget release function.
1365 */
1366void usb_initialize_gadget(struct device *parent, struct usb_gadget *gadget,
1367		void (*release)(struct device *dev))
1368{
1369	spin_lock_init(&gadget->state_lock);
1370	gadget->teardown = false;
1371	INIT_WORK(&gadget->work, usb_gadget_state_work);
1372	gadget->dev.parent = parent;
1373
1374	if (release)
1375		gadget->dev.release = release;
1376	else
1377		gadget->dev.release = usb_udc_nop_release;
1378
1379	device_initialize(&gadget->dev);
1380	gadget->dev.bus = &gadget_bus_type;
1381}
1382EXPORT_SYMBOL_GPL(usb_initialize_gadget);
1383
1384/**
1385 * usb_add_gadget - adds a new gadget to the udc class driver list
1386 * @gadget: the gadget to be added to the list.
1387 *
1388 * Returns zero on success, negative errno otherwise.
1389 * Does not do a final usb_put_gadget() if an error occurs.
1390 */
1391int usb_add_gadget(struct usb_gadget *gadget)
1392{
1393	struct usb_udc		*udc;
1394	int			ret = -ENOMEM;
1395
1396	udc = kzalloc(sizeof(*udc), GFP_KERNEL);
1397	if (!udc)
1398		goto error;
1399
1400	device_initialize(&udc->dev);
1401	udc->dev.release = usb_udc_release;
1402	udc->dev.class = &udc_class;
1403	udc->dev.groups = usb_udc_attr_groups;
1404	udc->dev.parent = gadget->dev.parent;
1405	ret = dev_set_name(&udc->dev, "%s",
1406			kobject_name(&gadget->dev.parent->kobj));
1407	if (ret)
1408		goto err_put_udc;
1409
1410	udc->gadget = gadget;
1411	gadget->udc = udc;
1412	mutex_init(&udc->connect_lock);
1413
1414	udc->started = false;
1415
1416	mutex_lock(&udc_lock);
1417	list_add_tail(&udc->list, &udc_list);
1418	mutex_unlock(&udc_lock);
1419	INIT_WORK(&udc->vbus_work, vbus_event_work);
1420
1421	ret = device_add(&udc->dev);
1422	if (ret)
1423		goto err_unlist_udc;
1424
1425	usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
1426	udc->vbus = true;
1427
1428	ret = ida_alloc(&gadget_id_numbers, GFP_KERNEL);
1429	if (ret < 0)
1430		goto err_del_udc;
1431	gadget->id_number = ret;
1432	dev_set_name(&gadget->dev, "gadget.%d", ret);
1433
1434	ret = device_add(&gadget->dev);
1435	if (ret)
1436		goto err_free_id;
1437
1438	ret = sysfs_create_link(&udc->dev.kobj,
1439				&gadget->dev.kobj, "gadget");
1440	if (ret)
1441		goto err_del_gadget;
1442
1443	return 0;
1444
1445 err_del_gadget:
1446	device_del(&gadget->dev);
1447
1448 err_free_id:
1449	ida_free(&gadget_id_numbers, gadget->id_number);
1450
1451 err_del_udc:
1452	flush_work(&gadget->work);
1453	device_del(&udc->dev);
1454
1455 err_unlist_udc:
1456	mutex_lock(&udc_lock);
1457	list_del(&udc->list);
1458	mutex_unlock(&udc_lock);
1459
1460 err_put_udc:
1461	put_device(&udc->dev);
1462
1463 error:
1464	return ret;
1465}
1466EXPORT_SYMBOL_GPL(usb_add_gadget);
1467
1468/**
1469 * usb_add_gadget_udc_release - adds a new gadget to the udc class driver list
1470 * @parent: the parent device to this udc. Usually the controller driver's
1471 * device.
1472 * @gadget: the gadget to be added to the list.
1473 * @release: a gadget release function.
1474 *
1475 * Returns zero on success, negative errno otherwise.
1476 * Calls the gadget release function in the latter case.
1477 */
1478int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
1479		void (*release)(struct device *dev))
1480{
1481	int	ret;
1482
1483	usb_initialize_gadget(parent, gadget, release);
1484	ret = usb_add_gadget(gadget);
1485	if (ret)
1486		usb_put_gadget(gadget);
1487	return ret;
1488}
1489EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release);
1490
1491/**
1492 * usb_get_gadget_udc_name - get the name of the first UDC controller
1493 * This functions returns the name of the first UDC controller in the system.
1494 * Please note that this interface is usefull only for legacy drivers which
1495 * assume that there is only one UDC controller in the system and they need to
1496 * get its name before initialization. There is no guarantee that the UDC
1497 * of the returned name will be still available, when gadget driver registers
1498 * itself.
1499 *
1500 * Returns pointer to string with UDC controller name on success, NULL
1501 * otherwise. Caller should kfree() returned string.
1502 */
1503char *usb_get_gadget_udc_name(void)
1504{
1505	struct usb_udc *udc;
1506	char *name = NULL;
1507
1508	/* For now we take the first available UDC */
1509	mutex_lock(&udc_lock);
1510	list_for_each_entry(udc, &udc_list, list) {
1511		if (!udc->driver) {
1512			name = kstrdup(udc->gadget->name, GFP_KERNEL);
1513			break;
1514		}
1515	}
1516	mutex_unlock(&udc_lock);
1517	return name;
1518}
1519EXPORT_SYMBOL_GPL(usb_get_gadget_udc_name);
1520
1521/**
1522 * usb_add_gadget_udc - adds a new gadget to the udc class driver list
1523 * @parent: the parent device to this udc. Usually the controller
1524 * driver's device.
1525 * @gadget: the gadget to be added to the list
1526 *
1527 * Returns zero on success, negative errno otherwise.
1528 */
1529int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
1530{
1531	return usb_add_gadget_udc_release(parent, gadget, NULL);
1532}
1533EXPORT_SYMBOL_GPL(usb_add_gadget_udc);
1534
1535/**
1536 * usb_del_gadget - deletes a gadget and unregisters its udc
1537 * @gadget: the gadget to be deleted.
1538 *
1539 * This will unbind @gadget, if it is bound.
1540 * It will not do a final usb_put_gadget().
1541 */
1542void usb_del_gadget(struct usb_gadget *gadget)
1543{
1544	struct usb_udc *udc = gadget->udc;
1545	unsigned long flags;
1546
1547	if (!udc)
1548		return;
1549
1550	dev_vdbg(gadget->dev.parent, "unregistering gadget\n");
1551
1552	mutex_lock(&udc_lock);
1553	list_del(&udc->list);
1554	mutex_unlock(&udc_lock);
1555
1556	kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
1557	sysfs_remove_link(&udc->dev.kobj, "gadget");
1558	device_del(&gadget->dev);
1559	/*
1560	 * Set the teardown flag before flushing the work to prevent new work
1561	 * from being scheduled while we are cleaning up.
1562	 */
1563	spin_lock_irqsave(&gadget->state_lock, flags);
1564	gadget->teardown = true;
1565	spin_unlock_irqrestore(&gadget->state_lock, flags);
1566	flush_work(&gadget->work);
1567	ida_free(&gadget_id_numbers, gadget->id_number);
1568	cancel_work_sync(&udc->vbus_work);
1569	device_unregister(&udc->dev);
1570}
1571EXPORT_SYMBOL_GPL(usb_del_gadget);
1572
1573/**
1574 * usb_del_gadget_udc - unregisters a gadget
1575 * @gadget: the gadget to be unregistered.
1576 *
1577 * Calls usb_del_gadget() and does a final usb_put_gadget().
1578 */
1579void usb_del_gadget_udc(struct usb_gadget *gadget)
1580{
1581	usb_del_gadget(gadget);
1582	usb_put_gadget(gadget);
1583}
1584EXPORT_SYMBOL_GPL(usb_del_gadget_udc);
1585
1586/* ------------------------------------------------------------------------- */
1587
1588static int gadget_match_driver(struct device *dev, const struct device_driver *drv)
1589{
1590	struct usb_gadget *gadget = dev_to_usb_gadget(dev);
1591	struct usb_udc *udc = gadget->udc;
1592	const struct usb_gadget_driver *driver = container_of(drv,
1593			struct usb_gadget_driver, driver);
1594
1595	/* If the driver specifies a udc_name, it must match the UDC's name */
1596	if (driver->udc_name &&
1597			strcmp(driver->udc_name, dev_name(&udc->dev)) != 0)
1598		return 0;
1599
1600	/* If the driver is already bound to a gadget, it doesn't match */
1601	if (driver->is_bound)
1602		return 0;
1603
1604	/* Otherwise any gadget driver matches any UDC */
1605	return 1;
1606}
1607
1608static int gadget_bind_driver(struct device *dev)
1609{
1610	struct usb_gadget *gadget = dev_to_usb_gadget(dev);
1611	struct usb_udc *udc = gadget->udc;
1612	struct usb_gadget_driver *driver = container_of(dev->driver,
1613			struct usb_gadget_driver, driver);
1614	int ret = 0;
1615
1616	mutex_lock(&udc_lock);
1617	if (driver->is_bound) {
1618		mutex_unlock(&udc_lock);
1619		return -ENXIO;		/* Driver binds to only one gadget */
1620	}
1621	driver->is_bound = true;
1622	udc->driver = driver;
1623	mutex_unlock(&udc_lock);
1624
1625	dev_dbg(&udc->dev, "binding gadget driver [%s]\n", driver->function);
1626
1627	usb_gadget_udc_set_speed(udc, driver->max_speed);
1628
1629	ret = driver->bind(udc->gadget, driver);
1630	if (ret)
1631		goto err_bind;
1632
1633	mutex_lock(&udc->connect_lock);
1634	ret = usb_gadget_udc_start_locked(udc);
1635	if (ret) {
1636		mutex_unlock(&udc->connect_lock);
1637		goto err_start;
1638	}
1639	usb_gadget_enable_async_callbacks(udc);
1640	udc->allow_connect = true;
1641	ret = usb_udc_connect_control_locked(udc);
1642	if (ret)
1643		goto err_connect_control;
1644
1645	mutex_unlock(&udc->connect_lock);
1646
1647	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
1648	return 0;
1649
1650 err_connect_control:
1651	udc->allow_connect = false;
1652	usb_gadget_disable_async_callbacks(udc);
1653	if (gadget->irq)
1654		synchronize_irq(gadget->irq);
1655	usb_gadget_udc_stop_locked(udc);
1656	mutex_unlock(&udc->connect_lock);
1657
1658 err_start:
1659	driver->unbind(udc->gadget);
1660
1661 err_bind:
1662	if (ret != -EISNAM)
1663		dev_err(&udc->dev, "failed to start %s: %d\n",
1664			driver->function, ret);
1665
1666	mutex_lock(&udc_lock);
1667	udc->driver = NULL;
1668	driver->is_bound = false;
1669	mutex_unlock(&udc_lock);
1670
1671	return ret;
1672}
1673
1674static void gadget_unbind_driver(struct device *dev)
1675{
1676	struct usb_gadget *gadget = dev_to_usb_gadget(dev);
1677	struct usb_udc *udc = gadget->udc;
1678	struct usb_gadget_driver *driver = udc->driver;
1679
1680	dev_dbg(&udc->dev, "unbinding gadget driver [%s]\n", driver->function);
1681
1682	udc->allow_connect = false;
1683	cancel_work_sync(&udc->vbus_work);
1684	mutex_lock(&udc->connect_lock);
1685	usb_gadget_disconnect_locked(gadget);
1686	usb_gadget_disable_async_callbacks(udc);
1687	if (gadget->irq)
1688		synchronize_irq(gadget->irq);
1689	mutex_unlock(&udc->connect_lock);
1690
1691	udc->driver->unbind(gadget);
1692
1693	mutex_lock(&udc->connect_lock);
1694	usb_gadget_udc_stop_locked(udc);
1695	mutex_unlock(&udc->connect_lock);
1696
1697	mutex_lock(&udc_lock);
1698	driver->is_bound = false;
1699	udc->driver = NULL;
1700	mutex_unlock(&udc_lock);
1701
1702	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
1703}
1704
1705/* ------------------------------------------------------------------------- */
1706
1707int usb_gadget_register_driver_owner(struct usb_gadget_driver *driver,
1708		struct module *owner, const char *mod_name)
1709{
1710	int ret;
1711
1712	if (!driver || !driver->bind || !driver->setup)
1713		return -EINVAL;
1714
1715	driver->driver.bus = &gadget_bus_type;
1716	driver->driver.owner = owner;
1717	driver->driver.mod_name = mod_name;
1718	driver->driver.probe_type = PROBE_FORCE_SYNCHRONOUS;
1719	ret = driver_register(&driver->driver);
1720	if (ret) {
1721		pr_warn("%s: driver registration failed: %d\n",
1722				driver->function, ret);
1723		return ret;
1724	}
1725
1726	mutex_lock(&udc_lock);
1727	if (!driver->is_bound) {
1728		if (driver->match_existing_only) {
1729			pr_warn("%s: couldn't find an available UDC or it's busy\n",
1730					driver->function);
1731			ret = -EBUSY;
1732		} else {
1733			pr_info("%s: couldn't find an available UDC\n",
1734					driver->function);
1735			ret = 0;
1736		}
1737	}
1738	mutex_unlock(&udc_lock);
1739
1740	if (ret)
1741		driver_unregister(&driver->driver);
1742	return ret;
1743}
1744EXPORT_SYMBOL_GPL(usb_gadget_register_driver_owner);
1745
1746int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
1747{
1748	if (!driver || !driver->unbind)
1749		return -EINVAL;
1750
1751	driver_unregister(&driver->driver);
1752	return 0;
1753}
1754EXPORT_SYMBOL_GPL(usb_gadget_unregister_driver);
1755
1756/* ------------------------------------------------------------------------- */
1757
1758static ssize_t srp_store(struct device *dev,
1759		struct device_attribute *attr, const char *buf, size_t n)
1760{
1761	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
1762
1763	if (sysfs_streq(buf, "1"))
1764		usb_gadget_wakeup(udc->gadget);
1765
1766	return n;
1767}
1768static DEVICE_ATTR_WO(srp);
1769
1770static ssize_t soft_connect_store(struct device *dev,
1771		struct device_attribute *attr, const char *buf, size_t n)
1772{
1773	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
1774	ssize_t			ret;
1775
1776	device_lock(&udc->gadget->dev);
1777	if (!udc->driver) {
1778		dev_err(dev, "soft-connect without a gadget driver\n");
1779		ret = -EOPNOTSUPP;
1780		goto out;
1781	}
1782
1783	if (sysfs_streq(buf, "connect")) {
1784		mutex_lock(&udc->connect_lock);
1785		usb_gadget_udc_start_locked(udc);
1786		usb_gadget_connect_locked(udc->gadget);
1787		mutex_unlock(&udc->connect_lock);
1788	} else if (sysfs_streq(buf, "disconnect")) {
1789		mutex_lock(&udc->connect_lock);
1790		usb_gadget_disconnect_locked(udc->gadget);
1791		usb_gadget_udc_stop_locked(udc);
1792		mutex_unlock(&udc->connect_lock);
1793	} else {
1794		dev_err(dev, "unsupported command '%s'\n", buf);
1795		ret = -EINVAL;
1796		goto out;
1797	}
1798
1799	ret = n;
1800out:
1801	device_unlock(&udc->gadget->dev);
1802	return ret;
1803}
1804static DEVICE_ATTR_WO(soft_connect);
1805
1806static ssize_t state_show(struct device *dev, struct device_attribute *attr,
1807			  char *buf)
1808{
1809	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
1810	struct usb_gadget	*gadget = udc->gadget;
1811
1812	return sprintf(buf, "%s\n", usb_state_string(gadget->state));
1813}
1814static DEVICE_ATTR_RO(state);
1815
1816static ssize_t function_show(struct device *dev, struct device_attribute *attr,
1817			     char *buf)
1818{
1819	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
1820	struct usb_gadget_driver *drv;
1821	int			rc = 0;
1822
1823	mutex_lock(&udc_lock);
1824	drv = udc->driver;
1825	if (drv && drv->function)
1826		rc = scnprintf(buf, PAGE_SIZE, "%s\n", drv->function);
1827	mutex_unlock(&udc_lock);
1828	return rc;
1829}
1830static DEVICE_ATTR_RO(function);
1831
1832#define USB_UDC_SPEED_ATTR(name, param)					\
1833ssize_t name##_show(struct device *dev,					\
1834		struct device_attribute *attr, char *buf)		\
1835{									\
1836	struct usb_udc *udc = container_of(dev, struct usb_udc, dev);	\
1837	return scnprintf(buf, PAGE_SIZE, "%s\n",			\
1838			usb_speed_string(udc->gadget->param));		\
1839}									\
1840static DEVICE_ATTR_RO(name)
1841
1842static USB_UDC_SPEED_ATTR(current_speed, speed);
1843static USB_UDC_SPEED_ATTR(maximum_speed, max_speed);
1844
1845#define USB_UDC_ATTR(name)					\
1846ssize_t name##_show(struct device *dev,				\
1847		struct device_attribute *attr, char *buf)	\
1848{								\
1849	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev); \
1850	struct usb_gadget	*gadget = udc->gadget;		\
1851								\
1852	return scnprintf(buf, PAGE_SIZE, "%d\n", gadget->name);	\
1853}								\
1854static DEVICE_ATTR_RO(name)
1855
1856static USB_UDC_ATTR(is_otg);
1857static USB_UDC_ATTR(is_a_peripheral);
1858static USB_UDC_ATTR(b_hnp_enable);
1859static USB_UDC_ATTR(a_hnp_support);
1860static USB_UDC_ATTR(a_alt_hnp_support);
1861static USB_UDC_ATTR(is_selfpowered);
1862
1863static struct attribute *usb_udc_attrs[] = {
1864	&dev_attr_srp.attr,
1865	&dev_attr_soft_connect.attr,
1866	&dev_attr_state.attr,
1867	&dev_attr_function.attr,
1868	&dev_attr_current_speed.attr,
1869	&dev_attr_maximum_speed.attr,
1870
1871	&dev_attr_is_otg.attr,
1872	&dev_attr_is_a_peripheral.attr,
1873	&dev_attr_b_hnp_enable.attr,
1874	&dev_attr_a_hnp_support.attr,
1875	&dev_attr_a_alt_hnp_support.attr,
1876	&dev_attr_is_selfpowered.attr,
1877	NULL,
1878};
1879
1880static const struct attribute_group usb_udc_attr_group = {
1881	.attrs = usb_udc_attrs,
1882};
1883
1884static const struct attribute_group *usb_udc_attr_groups[] = {
1885	&usb_udc_attr_group,
1886	NULL,
1887};
1888
1889static int usb_udc_uevent(const struct device *dev, struct kobj_uevent_env *env)
1890{
1891	const struct usb_udc	*udc = container_of(dev, struct usb_udc, dev);
1892	int			ret;
1893
1894	ret = add_uevent_var(env, "USB_UDC_NAME=%s", udc->gadget->name);
1895	if (ret) {
1896		dev_err(dev, "failed to add uevent USB_UDC_NAME\n");
1897		return ret;
1898	}
1899
1900	mutex_lock(&udc_lock);
1901	if (udc->driver)
1902		ret = add_uevent_var(env, "USB_UDC_DRIVER=%s",
1903				udc->driver->function);
1904	mutex_unlock(&udc_lock);
1905	if (ret) {
1906		dev_err(dev, "failed to add uevent USB_UDC_DRIVER\n");
1907		return ret;
1908	}
1909
1910	return 0;
1911}
1912
1913static const struct class udc_class = {
1914	.name		= "udc",
1915	.dev_uevent	= usb_udc_uevent,
1916};
1917
1918static const struct bus_type gadget_bus_type = {
1919	.name = "gadget",
1920	.probe = gadget_bind_driver,
1921	.remove = gadget_unbind_driver,
1922	.match = gadget_match_driver,
1923};
1924
1925static int __init usb_udc_init(void)
1926{
1927	int rc;
1928
1929	rc = class_register(&udc_class);
1930	if (rc)
1931		return rc;
1932
1933	rc = bus_register(&gadget_bus_type);
1934	if (rc)
1935		class_unregister(&udc_class);
1936	return rc;
1937}
1938subsys_initcall(usb_udc_init);
1939
1940static void __exit usb_udc_exit(void)
1941{
1942	bus_unregister(&gadget_bus_type);
1943	class_unregister(&udc_class);
1944}
1945module_exit(usb_udc_exit);
1946
1947MODULE_DESCRIPTION("UDC Framework");
1948MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
1949MODULE_LICENSE("GPL v2");