cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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core.c (49823B)


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