1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * udc.c - Core UDC Framework
4 *
5 * Copyright (C) 2010 Texas Instruments
6 * Author: Felipe Balbi <balbi@ti.com>
7 */
8
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/device.h>
12 #include <linux/list.h>
13 #include <linux/err.h>
14 #include <linux/dma-mapping.h>
15 #include <linux/sched/task_stack.h>
16 #include <linux/workqueue.h>
17
18 #include <linux/usb/ch9.h>
19 #include <linux/usb/gadget.h>
20 #include <linux/usb.h>
21
22 #include "trace.h"
23
24 /**
25 * struct usb_udc - describes one usb device controller
26 * @driver: the gadget driver pointer. For use by the class code
27 * @dev: the child device to the actual controller
28 * @gadget: the gadget. For use by the class code
29 * @list: for use by the udc class driver
30 * @vbus: for udcs who care about vbus status, this value is real vbus status;
31 * for udcs who do not care about vbus status, this value is always true
32 *
33 * This represents the internal data structure which is used by the UDC-class
34 * to hold information about udc driver and gadget together.
35 */
36 struct usb_udc {
37 struct usb_gadget_driver *driver;
38 struct usb_gadget *gadget;
39 struct device dev;
40 struct list_head list;
41 bool vbus;
42 };
43
44 static struct class *udc_class;
45 static LIST_HEAD(udc_list);
46 static LIST_HEAD(gadget_driver_pending_list);
47 static DEFINE_MUTEX(udc_lock);
48
49 static int udc_bind_to_driver(struct usb_udc *udc,
50 struct usb_gadget_driver *driver);
51
52 /* ------------------------------------------------------------------------- */
53
54 /**
55 * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
56 * @ep:the endpoint being configured
57 * @maxpacket_limit:value of maximum packet size limit
58 *
59 * This function should be used only in UDC drivers to initialize endpoint
60 * (usually in probe function).
61 */
usb_ep_set_maxpacket_limit(struct usb_ep * ep,unsigned maxpacket_limit)62 void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
63 unsigned maxpacket_limit)
64 {
65 ep->maxpacket_limit = maxpacket_limit;
66 ep->maxpacket = maxpacket_limit;
67
68 trace_usb_ep_set_maxpacket_limit(ep, 0);
69 }
70 EXPORT_SYMBOL_GPL(usb_ep_set_maxpacket_limit);
71
72 /**
73 * usb_ep_enable - configure endpoint, making it usable
74 * @ep:the endpoint being configured. may not be the endpoint named "ep0".
75 * drivers discover endpoints through the ep_list of a usb_gadget.
76 *
77 * When configurations are set, or when interface settings change, the driver
78 * will enable or disable the relevant endpoints. while it is enabled, an
79 * endpoint may be used for i/o until the driver receives a disconnect() from
80 * the host or until the endpoint is disabled.
81 *
82 * the ep0 implementation (which calls this routine) must ensure that the
83 * hardware capabilities of each endpoint match the descriptor provided
84 * for it. for example, an endpoint named "ep2in-bulk" would be usable
85 * for interrupt transfers as well as bulk, but it likely couldn't be used
86 * for iso transfers or for endpoint 14. some endpoints are fully
87 * configurable, with more generic names like "ep-a". (remember that for
88 * USB, "in" means "towards the USB host".)
89 *
90 * This routine must be called in process context.
91 *
92 * returns zero, or a negative error code.
93 */
usb_ep_enable(struct usb_ep * ep)94 int usb_ep_enable(struct usb_ep *ep)
95 {
96 int ret = 0;
97
98 if (ep->enabled)
99 goto out;
100
101 /* UDC drivers can't handle endpoints with maxpacket size 0 */
102 if (usb_endpoint_maxp(ep->desc) == 0) {
103 /*
104 * We should log an error message here, but we can't call
105 * dev_err() because there's no way to find the gadget
106 * given only ep.
107 */
108 ret = -EINVAL;
109 goto out;
110 }
111
112 ret = ep->ops->enable(ep, ep->desc);
113 if (ret)
114 goto out;
115
116 ep->enabled = true;
117
118 out:
119 trace_usb_ep_enable(ep, ret);
120
121 return ret;
122 }
123 EXPORT_SYMBOL_GPL(usb_ep_enable);
124
125 /**
126 * usb_ep_disable - endpoint is no longer usable
127 * @ep:the endpoint being unconfigured. may not be the endpoint named "ep0".
128 *
129 * no other task may be using this endpoint when this is called.
130 * any pending and uncompleted requests will complete with status
131 * indicating disconnect (-ESHUTDOWN) before this call returns.
132 * gadget drivers must call usb_ep_enable() again before queueing
133 * requests to the endpoint.
134 *
135 * This routine must be called in process context.
136 *
137 * returns zero, or a negative error code.
138 */
usb_ep_disable(struct usb_ep * ep)139 int usb_ep_disable(struct usb_ep *ep)
140 {
141 int ret = 0;
142
143 if (!ep->enabled)
144 goto out;
145
146 ret = ep->ops->disable(ep);
147 if (ret)
148 goto out;
149
150 ep->enabled = false;
151
152 out:
153 trace_usb_ep_disable(ep, ret);
154
155 return ret;
156 }
157 EXPORT_SYMBOL_GPL(usb_ep_disable);
158
159 /**
160 * usb_ep_alloc_request - allocate a request object to use with this endpoint
161 * @ep:the endpoint to be used with with the request
162 * @gfp_flags:GFP_* flags to use
163 *
164 * Request objects must be allocated with this call, since they normally
165 * need controller-specific setup and may even need endpoint-specific
166 * resources such as allocation of DMA descriptors.
167 * Requests may be submitted with usb_ep_queue(), and receive a single
168 * completion callback. Free requests with usb_ep_free_request(), when
169 * they are no longer needed.
170 *
171 * Returns the request, or null if one could not be allocated.
172 */
usb_ep_alloc_request(struct usb_ep * ep,gfp_t gfp_flags)173 struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
174 gfp_t gfp_flags)
175 {
176 struct usb_request *req = NULL;
177
178 req = ep->ops->alloc_request(ep, gfp_flags);
179
180 trace_usb_ep_alloc_request(ep, req, req ? 0 : -ENOMEM);
181
182 return req;
183 }
184 EXPORT_SYMBOL_GPL(usb_ep_alloc_request);
185
186 /**
187 * usb_ep_free_request - frees a request object
188 * @ep:the endpoint associated with the request
189 * @req:the request being freed
190 *
191 * Reverses the effect of usb_ep_alloc_request().
192 * Caller guarantees the request is not queued, and that it will
193 * no longer be requeued (or otherwise used).
194 */
usb_ep_free_request(struct usb_ep * ep,struct usb_request * req)195 void usb_ep_free_request(struct usb_ep *ep,
196 struct usb_request *req)
197 {
198 trace_usb_ep_free_request(ep, req, 0);
199 ep->ops->free_request(ep, req);
200 }
201 EXPORT_SYMBOL_GPL(usb_ep_free_request);
202
203 /**
204 * usb_ep_queue - queues (submits) an I/O request to an endpoint.
205 * @ep:the endpoint associated with the request
206 * @req:the request being submitted
207 * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
208 * pre-allocate all necessary memory with the request.
209 *
210 * This tells the device controller to perform the specified request through
211 * that endpoint (reading or writing a buffer). When the request completes,
212 * including being canceled by usb_ep_dequeue(), the request's completion
213 * routine is called to return the request to the driver. Any endpoint
214 * (except control endpoints like ep0) may have more than one transfer
215 * request queued; they complete in FIFO order. Once a gadget driver
216 * submits a request, that request may not be examined or modified until it
217 * is given back to that driver through the completion callback.
218 *
219 * Each request is turned into one or more packets. The controller driver
220 * never merges adjacent requests into the same packet. OUT transfers
221 * will sometimes use data that's already buffered in the hardware.
222 * Drivers can rely on the fact that the first byte of the request's buffer
223 * always corresponds to the first byte of some USB packet, for both
224 * IN and OUT transfers.
225 *
226 * Bulk endpoints can queue any amount of data; the transfer is packetized
227 * automatically. The last packet will be short if the request doesn't fill it
228 * out completely. Zero length packets (ZLPs) should be avoided in portable
229 * protocols since not all usb hardware can successfully handle zero length
230 * packets. (ZLPs may be explicitly written, and may be implicitly written if
231 * the request 'zero' flag is set.) Bulk endpoints may also be used
232 * for interrupt transfers; but the reverse is not true, and some endpoints
233 * won't support every interrupt transfer. (Such as 768 byte packets.)
234 *
235 * Interrupt-only endpoints are less functional than bulk endpoints, for
236 * example by not supporting queueing or not handling buffers that are
237 * larger than the endpoint's maxpacket size. They may also treat data
238 * toggle differently.
239 *
240 * Control endpoints ... after getting a setup() callback, the driver queues
241 * one response (even if it would be zero length). That enables the
242 * status ack, after transferring data as specified in the response. Setup
243 * functions may return negative error codes to generate protocol stalls.
244 * (Note that some USB device controllers disallow protocol stall responses
245 * in some cases.) When control responses are deferred (the response is
246 * written after the setup callback returns), then usb_ep_set_halt() may be
247 * used on ep0 to trigger protocol stalls. Depending on the controller,
248 * it may not be possible to trigger a status-stage protocol stall when the
249 * data stage is over, that is, from within the response's completion
250 * routine.
251 *
252 * For periodic endpoints, like interrupt or isochronous ones, the usb host
253 * arranges to poll once per interval, and the gadget driver usually will
254 * have queued some data to transfer at that time.
255 *
256 * Note that @req's ->complete() callback must never be called from
257 * within usb_ep_queue() as that can create deadlock situations.
258 *
259 * This routine may be called in interrupt context.
260 *
261 * Returns zero, or a negative error code. Endpoints that are not enabled
262 * report errors; errors will also be
263 * reported when the usb peripheral is disconnected.
264 *
265 * If and only if @req is successfully queued (the return value is zero),
266 * @req->complete() will be called exactly once, when the Gadget core and
267 * UDC are finished with the request. When the completion function is called,
268 * control of the request is returned to the device driver which submitted it.
269 * The completion handler may then immediately free or reuse @req.
270 */
usb_ep_queue(struct usb_ep * ep,struct usb_request * req,gfp_t gfp_flags)271 int usb_ep_queue(struct usb_ep *ep,
272 struct usb_request *req, gfp_t gfp_flags)
273 {
274 int ret = 0;
275
276 if (WARN_ON_ONCE(!ep->enabled && ep->address)) {
277 ret = -ESHUTDOWN;
278 goto out;
279 }
280
281 ret = ep->ops->queue(ep, req, gfp_flags);
282
283 out:
284 trace_usb_ep_queue(ep, req, ret);
285
286 return ret;
287 }
288 EXPORT_SYMBOL_GPL(usb_ep_queue);
289
290 /**
291 * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
292 * @ep:the endpoint associated with the request
293 * @req:the request being canceled
294 *
295 * If the request is still active on the endpoint, it is dequeued and
296 * eventually its completion routine is called (with status -ECONNRESET);
297 * else a negative error code is returned. This routine is asynchronous,
298 * that is, it may return before the completion routine runs.
299 *
300 * Note that some hardware can't clear out write fifos (to unlink the request
301 * at the head of the queue) except as part of disconnecting from usb. Such
302 * restrictions prevent drivers from supporting configuration changes,
303 * even to configuration zero (a "chapter 9" requirement).
304 *
305 * This routine may be called in interrupt context.
306 */
usb_ep_dequeue(struct usb_ep * ep,struct usb_request * req)307 int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
308 {
309 int ret;
310
311 ret = ep->ops->dequeue(ep, req);
312 trace_usb_ep_dequeue(ep, req, ret);
313
314 return ret;
315 }
316 EXPORT_SYMBOL_GPL(usb_ep_dequeue);
317
318 /**
319 * usb_ep_set_halt - sets the endpoint halt feature.
320 * @ep: the non-isochronous endpoint being stalled
321 *
322 * Use this to stall an endpoint, perhaps as an error report.
323 * Except for control endpoints,
324 * the endpoint stays halted (will not stream any data) until the host
325 * clears this feature; drivers may need to empty the endpoint's request
326 * queue first, to make sure no inappropriate transfers happen.
327 *
328 * Note that while an endpoint CLEAR_FEATURE will be invisible to the
329 * gadget driver, a SET_INTERFACE will not be. To reset endpoints for the
330 * current altsetting, see usb_ep_clear_halt(). When switching altsettings,
331 * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
332 *
333 * This routine may be called in interrupt context.
334 *
335 * Returns zero, or a negative error code. On success, this call sets
336 * underlying hardware state that blocks data transfers.
337 * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
338 * transfer requests are still queued, or if the controller hardware
339 * (usually a FIFO) still holds bytes that the host hasn't collected.
340 */
usb_ep_set_halt(struct usb_ep * ep)341 int usb_ep_set_halt(struct usb_ep *ep)
342 {
343 int ret;
344
345 ret = ep->ops->set_halt(ep, 1);
346 trace_usb_ep_set_halt(ep, ret);
347
348 return ret;
349 }
350 EXPORT_SYMBOL_GPL(usb_ep_set_halt);
351
352 /**
353 * usb_ep_clear_halt - clears endpoint halt, and resets toggle
354 * @ep:the bulk or interrupt endpoint being reset
355 *
356 * Use this when responding to the standard usb "set interface" request,
357 * for endpoints that aren't reconfigured, after clearing any other state
358 * in the endpoint's i/o queue.
359 *
360 * This routine may be called in interrupt context.
361 *
362 * Returns zero, or a negative error code. On success, this call clears
363 * the underlying hardware state reflecting endpoint halt and data toggle.
364 * Note that some hardware can't support this request (like pxa2xx_udc),
365 * and accordingly can't correctly implement interface altsettings.
366 */
usb_ep_clear_halt(struct usb_ep * ep)367 int usb_ep_clear_halt(struct usb_ep *ep)
368 {
369 int ret;
370
371 ret = ep->ops->set_halt(ep, 0);
372 trace_usb_ep_clear_halt(ep, ret);
373
374 return ret;
375 }
376 EXPORT_SYMBOL_GPL(usb_ep_clear_halt);
377
378 /**
379 * usb_ep_set_wedge - sets the halt feature and ignores clear requests
380 * @ep: the endpoint being wedged
381 *
382 * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT)
383 * requests. If the gadget driver clears the halt status, it will
384 * automatically unwedge the endpoint.
385 *
386 * This routine may be called in interrupt context.
387 *
388 * Returns zero on success, else negative errno.
389 */
usb_ep_set_wedge(struct usb_ep * ep)390 int usb_ep_set_wedge(struct usb_ep *ep)
391 {
392 int ret;
393
394 if (ep->ops->set_wedge)
395 ret = ep->ops->set_wedge(ep);
396 else
397 ret = ep->ops->set_halt(ep, 1);
398
399 trace_usb_ep_set_wedge(ep, ret);
400
401 return ret;
402 }
403 EXPORT_SYMBOL_GPL(usb_ep_set_wedge);
404
405 /**
406 * usb_ep_fifo_status - returns number of bytes in fifo, or error
407 * @ep: the endpoint whose fifo status is being checked.
408 *
409 * FIFO endpoints may have "unclaimed data" in them in certain cases,
410 * such as after aborted transfers. Hosts may not have collected all
411 * the IN data written by the gadget driver (and reported by a request
412 * completion). The gadget driver may not have collected all the data
413 * written OUT to it by the host. Drivers that need precise handling for
414 * fault reporting or recovery may need to use this call.
415 *
416 * This routine may be called in interrupt context.
417 *
418 * This returns the number of such bytes in the fifo, or a negative
419 * errno if the endpoint doesn't use a FIFO or doesn't support such
420 * precise handling.
421 */
usb_ep_fifo_status(struct usb_ep * ep)422 int usb_ep_fifo_status(struct usb_ep *ep)
423 {
424 int ret;
425
426 if (ep->ops->fifo_status)
427 ret = ep->ops->fifo_status(ep);
428 else
429 ret = -EOPNOTSUPP;
430
431 trace_usb_ep_fifo_status(ep, ret);
432
433 return ret;
434 }
435 EXPORT_SYMBOL_GPL(usb_ep_fifo_status);
436
437 /**
438 * usb_ep_fifo_flush - flushes contents of a fifo
439 * @ep: the endpoint whose fifo is being flushed.
440 *
441 * This call may be used to flush the "unclaimed data" that may exist in
442 * an endpoint fifo after abnormal transaction terminations. The call
443 * must never be used except when endpoint is not being used for any
444 * protocol translation.
445 *
446 * This routine may be called in interrupt context.
447 */
usb_ep_fifo_flush(struct usb_ep * ep)448 void usb_ep_fifo_flush(struct usb_ep *ep)
449 {
450 if (ep->ops->fifo_flush)
451 ep->ops->fifo_flush(ep);
452
453 trace_usb_ep_fifo_flush(ep, 0);
454 }
455 EXPORT_SYMBOL_GPL(usb_ep_fifo_flush);
456
457 /* ------------------------------------------------------------------------- */
458
459 /**
460 * usb_gadget_frame_number - returns the current frame number
461 * @gadget: controller that reports the frame number
462 *
463 * Returns the usb frame number, normally eleven bits from a SOF packet,
464 * or negative errno if this device doesn't support this capability.
465 */
usb_gadget_frame_number(struct usb_gadget * gadget)466 int usb_gadget_frame_number(struct usb_gadget *gadget)
467 {
468 int ret;
469
470 ret = gadget->ops->get_frame(gadget);
471
472 trace_usb_gadget_frame_number(gadget, ret);
473
474 return ret;
475 }
476 EXPORT_SYMBOL_GPL(usb_gadget_frame_number);
477
478 /**
479 * usb_gadget_wakeup - tries to wake up the host connected to this gadget
480 * @gadget: controller used to wake up the host
481 *
482 * Returns zero on success, else negative error code if the hardware
483 * doesn't support such attempts, or its support has not been enabled
484 * by the usb host. Drivers must return device descriptors that report
485 * their ability to support this, or hosts won't enable it.
486 *
487 * This may also try to use SRP to wake the host and start enumeration,
488 * even if OTG isn't otherwise in use. OTG devices may also start
489 * remote wakeup even when hosts don't explicitly enable it.
490 */
usb_gadget_wakeup(struct usb_gadget * gadget)491 int usb_gadget_wakeup(struct usb_gadget *gadget)
492 {
493 int ret = 0;
494
495 if (!gadget->ops->wakeup) {
496 ret = -EOPNOTSUPP;
497 goto out;
498 }
499
500 ret = gadget->ops->wakeup(gadget);
501
502 out:
503 trace_usb_gadget_wakeup(gadget, ret);
504
505 return ret;
506 }
507 EXPORT_SYMBOL_GPL(usb_gadget_wakeup);
508
509 /**
510 * usb_gadget_set_selfpowered - sets the device selfpowered feature.
511 * @gadget:the device being declared as self-powered
512 *
513 * this affects the device status reported by the hardware driver
514 * to reflect that it now has a local power supply.
515 *
516 * returns zero on success, else negative errno.
517 */
usb_gadget_set_selfpowered(struct usb_gadget * gadget)518 int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
519 {
520 int ret = 0;
521
522 if (!gadget->ops->set_selfpowered) {
523 ret = -EOPNOTSUPP;
524 goto out;
525 }
526
527 ret = gadget->ops->set_selfpowered(gadget, 1);
528
529 out:
530 trace_usb_gadget_set_selfpowered(gadget, ret);
531
532 return ret;
533 }
534 EXPORT_SYMBOL_GPL(usb_gadget_set_selfpowered);
535
536 /**
537 * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
538 * @gadget:the device being declared as bus-powered
539 *
540 * this affects the device status reported by the hardware driver.
541 * some hardware may not support bus-powered operation, in which
542 * case this feature's value can never change.
543 *
544 * returns zero on success, else negative errno.
545 */
usb_gadget_clear_selfpowered(struct usb_gadget * gadget)546 int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
547 {
548 int ret = 0;
549
550 if (!gadget->ops->set_selfpowered) {
551 ret = -EOPNOTSUPP;
552 goto out;
553 }
554
555 ret = gadget->ops->set_selfpowered(gadget, 0);
556
557 out:
558 trace_usb_gadget_clear_selfpowered(gadget, ret);
559
560 return ret;
561 }
562 EXPORT_SYMBOL_GPL(usb_gadget_clear_selfpowered);
563
564 /**
565 * usb_gadget_vbus_connect - Notify controller that VBUS is powered
566 * @gadget:The device which now has VBUS power.
567 * Context: can sleep
568 *
569 * This call is used by a driver for an external transceiver (or GPIO)
570 * that detects a VBUS power session starting. Common responses include
571 * resuming the controller, activating the D+ (or D-) pullup to let the
572 * host detect that a USB device is attached, and starting to draw power
573 * (8mA or possibly more, especially after SET_CONFIGURATION).
574 *
575 * Returns zero on success, else negative errno.
576 */
usb_gadget_vbus_connect(struct usb_gadget * gadget)577 int usb_gadget_vbus_connect(struct usb_gadget *gadget)
578 {
579 int ret = 0;
580
581 if (!gadget->ops->vbus_session) {
582 ret = -EOPNOTSUPP;
583 goto out;
584 }
585
586 ret = gadget->ops->vbus_session(gadget, 1);
587
588 out:
589 trace_usb_gadget_vbus_connect(gadget, ret);
590
591 return ret;
592 }
593 EXPORT_SYMBOL_GPL(usb_gadget_vbus_connect);
594
595 /**
596 * usb_gadget_vbus_draw - constrain controller's VBUS power usage
597 * @gadget:The device whose VBUS usage is being described
598 * @mA:How much current to draw, in milliAmperes. This should be twice
599 * the value listed in the configuration descriptor bMaxPower field.
600 *
601 * This call is used by gadget drivers during SET_CONFIGURATION calls,
602 * reporting how much power the device may consume. For example, this
603 * could affect how quickly batteries are recharged.
604 *
605 * Returns zero on success, else negative errno.
606 */
usb_gadget_vbus_draw(struct usb_gadget * gadget,unsigned mA)607 int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
608 {
609 int ret = 0;
610
611 if (!gadget->ops->vbus_draw) {
612 ret = -EOPNOTSUPP;
613 goto out;
614 }
615
616 ret = gadget->ops->vbus_draw(gadget, mA);
617 if (!ret)
618 gadget->mA = mA;
619
620 out:
621 trace_usb_gadget_vbus_draw(gadget, ret);
622
623 return ret;
624 }
625 EXPORT_SYMBOL_GPL(usb_gadget_vbus_draw);
626
627 /**
628 * usb_gadget_vbus_disconnect - notify controller about VBUS session end
629 * @gadget:the device whose VBUS supply is being described
630 * Context: can sleep
631 *
632 * This call is used by a driver for an external transceiver (or GPIO)
633 * that detects a VBUS power session ending. Common responses include
634 * reversing everything done in usb_gadget_vbus_connect().
635 *
636 * Returns zero on success, else negative errno.
637 */
usb_gadget_vbus_disconnect(struct usb_gadget * gadget)638 int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
639 {
640 int ret = 0;
641
642 if (!gadget->ops->vbus_session) {
643 ret = -EOPNOTSUPP;
644 goto out;
645 }
646
647 ret = gadget->ops->vbus_session(gadget, 0);
648
649 out:
650 trace_usb_gadget_vbus_disconnect(gadget, ret);
651
652 return ret;
653 }
654 EXPORT_SYMBOL_GPL(usb_gadget_vbus_disconnect);
655
656 /**
657 * usb_gadget_connect - software-controlled connect to USB host
658 * @gadget:the peripheral being connected
659 *
660 * Enables the D+ (or potentially D-) pullup. The host will start
661 * enumerating this gadget when the pullup is active and a VBUS session
662 * is active (the link is powered). This pullup is always enabled unless
663 * usb_gadget_disconnect() has been used to disable it.
664 *
665 * Returns zero on success, else negative errno.
666 */
usb_gadget_connect(struct usb_gadget * gadget)667 int usb_gadget_connect(struct usb_gadget *gadget)
668 {
669 int ret = 0;
670
671 if (!gadget->ops->pullup) {
672 ret = -EOPNOTSUPP;
673 goto out;
674 }
675
676 if (gadget->deactivated) {
677 /*
678 * If gadget is deactivated we only save new state.
679 * Gadget will be connected automatically after activation.
680 */
681 gadget->connected = true;
682 goto out;
683 }
684
685 ret = gadget->ops->pullup(gadget, 1);
686 if (!ret)
687 gadget->connected = 1;
688
689 out:
690 trace_usb_gadget_connect(gadget, ret);
691
692 return ret;
693 }
694 EXPORT_SYMBOL_GPL(usb_gadget_connect);
695
696 /**
697 * usb_gadget_disconnect - software-controlled disconnect from USB host
698 * @gadget:the peripheral being disconnected
699 *
700 * Disables the D+ (or potentially D-) pullup, which the host may see
701 * as a disconnect (when a VBUS session is active). Not all systems
702 * support software pullup controls.
703 *
704 * Following a successful disconnect, invoke the ->disconnect() callback
705 * for the current gadget driver so that UDC drivers don't need to.
706 *
707 * Returns zero on success, else negative errno.
708 */
usb_gadget_disconnect(struct usb_gadget * gadget)709 int usb_gadget_disconnect(struct usb_gadget *gadget)
710 {
711 int ret = 0;
712
713 if (!gadget->ops->pullup) {
714 ret = -EOPNOTSUPP;
715 goto out;
716 }
717
718 if (!gadget->connected)
719 goto out;
720
721 if (gadget->deactivated) {
722 /*
723 * If gadget is deactivated we only save new state.
724 * Gadget will stay disconnected after activation.
725 */
726 gadget->connected = false;
727 goto out;
728 }
729
730 ret = gadget->ops->pullup(gadget, 0);
731 if (!ret) {
732 gadget->connected = 0;
733 gadget->udc->driver->disconnect(gadget);
734 }
735
736 out:
737 trace_usb_gadget_disconnect(gadget, ret);
738
739 return ret;
740 }
741 EXPORT_SYMBOL_GPL(usb_gadget_disconnect);
742
743 /**
744 * usb_gadget_deactivate - deactivate function which is not ready to work
745 * @gadget: the peripheral being deactivated
746 *
747 * This routine may be used during the gadget driver bind() call to prevent
748 * the peripheral from ever being visible to the USB host, unless later
749 * usb_gadget_activate() is called. For example, user mode components may
750 * need to be activated before the system can talk to hosts.
751 *
752 * Returns zero on success, else negative errno.
753 */
usb_gadget_deactivate(struct usb_gadget * gadget)754 int usb_gadget_deactivate(struct usb_gadget *gadget)
755 {
756 int ret = 0;
757
758 if (gadget->deactivated)
759 goto out;
760
761 if (gadget->connected) {
762 ret = usb_gadget_disconnect(gadget);
763 if (ret)
764 goto out;
765
766 /*
767 * If gadget was being connected before deactivation, we want
768 * to reconnect it in usb_gadget_activate().
769 */
770 gadget->connected = true;
771 }
772 gadget->deactivated = true;
773
774 out:
775 trace_usb_gadget_deactivate(gadget, ret);
776
777 return ret;
778 }
779 EXPORT_SYMBOL_GPL(usb_gadget_deactivate);
780
781 /**
782 * usb_gadget_activate - activate function which is not ready to work
783 * @gadget: the peripheral being activated
784 *
785 * This routine activates gadget which was previously deactivated with
786 * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed.
787 *
788 * Returns zero on success, else negative errno.
789 */
usb_gadget_activate(struct usb_gadget * gadget)790 int usb_gadget_activate(struct usb_gadget *gadget)
791 {
792 int ret = 0;
793
794 if (!gadget->deactivated)
795 goto out;
796
797 gadget->deactivated = false;
798
799 /*
800 * If gadget has been connected before deactivation, or became connected
801 * while it was being deactivated, we call usb_gadget_connect().
802 */
803 if (gadget->connected)
804 ret = usb_gadget_connect(gadget);
805
806 out:
807 trace_usb_gadget_activate(gadget, ret);
808
809 return ret;
810 }
811 EXPORT_SYMBOL_GPL(usb_gadget_activate);
812
813 /* ------------------------------------------------------------------------- */
814
815 #ifdef CONFIG_HAS_DMA
816
usb_gadget_map_request_by_dev(struct device * dev,struct usb_request * req,int is_in)817 int usb_gadget_map_request_by_dev(struct device *dev,
818 struct usb_request *req, int is_in)
819 {
820 if (req->length == 0)
821 return 0;
822
823 if (req->num_sgs) {
824 int mapped;
825
826 mapped = dma_map_sg(dev, req->sg, req->num_sgs,
827 is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
828 if (mapped == 0) {
829 dev_err(dev, "failed to map SGs\n");
830 return -EFAULT;
831 }
832
833 req->num_mapped_sgs = mapped;
834 } else {
835 if (is_vmalloc_addr(req->buf)) {
836 dev_err(dev, "buffer is not dma capable\n");
837 return -EFAULT;
838 } else if (object_is_on_stack(req->buf)) {
839 dev_err(dev, "buffer is on stack\n");
840 return -EFAULT;
841 }
842
843 req->dma = dma_map_single(dev, req->buf, req->length,
844 is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
845
846 if (dma_mapping_error(dev, req->dma)) {
847 dev_err(dev, "failed to map buffer\n");
848 return -EFAULT;
849 }
850
851 req->dma_mapped = 1;
852 }
853
854 return 0;
855 }
856 EXPORT_SYMBOL_GPL(usb_gadget_map_request_by_dev);
857
usb_gadget_map_request(struct usb_gadget * gadget,struct usb_request * req,int is_in)858 int usb_gadget_map_request(struct usb_gadget *gadget,
859 struct usb_request *req, int is_in)
860 {
861 return usb_gadget_map_request_by_dev(gadget->dev.parent, req, is_in);
862 }
863 EXPORT_SYMBOL_GPL(usb_gadget_map_request);
864
usb_gadget_unmap_request_by_dev(struct device * dev,struct usb_request * req,int is_in)865 void usb_gadget_unmap_request_by_dev(struct device *dev,
866 struct usb_request *req, int is_in)
867 {
868 if (req->length == 0)
869 return;
870
871 if (req->num_mapped_sgs) {
872 dma_unmap_sg(dev, req->sg, req->num_sgs,
873 is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
874
875 req->num_mapped_sgs = 0;
876 } else if (req->dma_mapped) {
877 dma_unmap_single(dev, req->dma, req->length,
878 is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
879 req->dma_mapped = 0;
880 }
881 }
882 EXPORT_SYMBOL_GPL(usb_gadget_unmap_request_by_dev);
883
usb_gadget_unmap_request(struct usb_gadget * gadget,struct usb_request * req,int is_in)884 void usb_gadget_unmap_request(struct usb_gadget *gadget,
885 struct usb_request *req, int is_in)
886 {
887 usb_gadget_unmap_request_by_dev(gadget->dev.parent, req, is_in);
888 }
889 EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);
890
891 #endif /* CONFIG_HAS_DMA */
892
893 /* ------------------------------------------------------------------------- */
894
895 /**
896 * usb_gadget_giveback_request - give the request back to the gadget layer
897 * @ep: the endpoint to be used with with the request
898 * @req: the request being given back
899 *
900 * Context: in_interrupt()
901 *
902 * This is called by device controller drivers in order to return the
903 * completed request back to the gadget layer.
904 */
usb_gadget_giveback_request(struct usb_ep * ep,struct usb_request * req)905 void usb_gadget_giveback_request(struct usb_ep *ep,
906 struct usb_request *req)
907 {
908 if (likely(req->status == 0))
909 usb_led_activity(USB_LED_EVENT_GADGET);
910
911 trace_usb_gadget_giveback_request(ep, req, 0);
912
913 req->complete(ep, req);
914 }
915 EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
916
917 /* ------------------------------------------------------------------------- */
918
919 /**
920 * gadget_find_ep_by_name - returns ep whose name is the same as sting passed
921 * in second parameter or NULL if searched endpoint not found
922 * @g: controller to check for quirk
923 * @name: name of searched endpoint
924 */
gadget_find_ep_by_name(struct usb_gadget * g,const char * name)925 struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g, const char *name)
926 {
927 struct usb_ep *ep;
928
929 gadget_for_each_ep(ep, g) {
930 if (!strcmp(ep->name, name))
931 return ep;
932 }
933
934 return NULL;
935 }
936 EXPORT_SYMBOL_GPL(gadget_find_ep_by_name);
937
938 /* ------------------------------------------------------------------------- */
939
usb_gadget_ep_match_desc(struct usb_gadget * gadget,struct usb_ep * ep,struct usb_endpoint_descriptor * desc,struct usb_ss_ep_comp_descriptor * ep_comp)940 int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
941 struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
942 struct usb_ss_ep_comp_descriptor *ep_comp)
943 {
944 u8 type;
945 u16 max;
946 int num_req_streams = 0;
947
948 /* endpoint already claimed? */
949 if (ep->claimed)
950 return 0;
951
952 type = usb_endpoint_type(desc);
953 max = usb_endpoint_maxp(desc);
954
955 if (usb_endpoint_dir_in(desc) && !ep->caps.dir_in)
956 return 0;
957 if (usb_endpoint_dir_out(desc) && !ep->caps.dir_out)
958 return 0;
959
960 if (max > ep->maxpacket_limit)
961 return 0;
962
963 /* "high bandwidth" works only at high speed */
964 if (!gadget_is_dualspeed(gadget) && usb_endpoint_maxp_mult(desc) > 1)
965 return 0;
966
967 switch (type) {
968 case USB_ENDPOINT_XFER_CONTROL:
969 /* only support ep0 for portable CONTROL traffic */
970 return 0;
971 case USB_ENDPOINT_XFER_ISOC:
972 if (!ep->caps.type_iso)
973 return 0;
974 /* ISO: limit 1023 bytes full speed, 1024 high/super speed */
975 if (!gadget_is_dualspeed(gadget) && max > 1023)
976 return 0;
977 break;
978 case USB_ENDPOINT_XFER_BULK:
979 if (!ep->caps.type_bulk)
980 return 0;
981 if (ep_comp && gadget_is_superspeed(gadget)) {
982 /* Get the number of required streams from the
983 * EP companion descriptor and see if the EP
984 * matches it
985 */
986 num_req_streams = ep_comp->bmAttributes & 0x1f;
987 if (num_req_streams > ep->max_streams)
988 return 0;
989 }
990 break;
991 case USB_ENDPOINT_XFER_INT:
992 /* Bulk endpoints handle interrupt transfers,
993 * except the toggle-quirky iso-synch kind
994 */
995 if (!ep->caps.type_int && !ep->caps.type_bulk)
996 return 0;
997 /* INT: limit 64 bytes full speed, 1024 high/super speed */
998 if (!gadget_is_dualspeed(gadget) && max > 64)
999 return 0;
1000 break;
1001 }
1002
1003 return 1;
1004 }
1005 EXPORT_SYMBOL_GPL(usb_gadget_ep_match_desc);
1006
1007 /* ------------------------------------------------------------------------- */
1008
usb_gadget_state_work(struct work_struct * work)1009 static void usb_gadget_state_work(struct work_struct *work)
1010 {
1011 struct usb_gadget *gadget = work_to_gadget(work);
1012 struct usb_udc *udc = gadget->udc;
1013
1014 if (udc)
1015 sysfs_notify(&udc->dev.kobj, NULL, "state");
1016 }
1017
usb_gadget_set_state(struct usb_gadget * gadget,enum usb_device_state state)1018 void usb_gadget_set_state(struct usb_gadget *gadget,
1019 enum usb_device_state state)
1020 {
1021 gadget->state = state;
1022 schedule_work(&gadget->work);
1023 }
1024 EXPORT_SYMBOL_GPL(usb_gadget_set_state);
1025
1026 /* ------------------------------------------------------------------------- */
1027
usb_udc_connect_control(struct usb_udc * udc)1028 static void usb_udc_connect_control(struct usb_udc *udc)
1029 {
1030 if (udc->vbus)
1031 usb_gadget_connect(udc->gadget);
1032 else
1033 usb_gadget_disconnect(udc->gadget);
1034 }
1035
1036 /**
1037 * usb_udc_vbus_handler - updates the udc core vbus status, and try to
1038 * connect or disconnect gadget
1039 * @gadget: The gadget which vbus change occurs
1040 * @status: The vbus status
1041 *
1042 * The udc driver calls it when it wants to connect or disconnect gadget
1043 * according to vbus status.
1044 */
usb_udc_vbus_handler(struct usb_gadget * gadget,bool status)1045 void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status)
1046 {
1047 struct usb_udc *udc = gadget->udc;
1048
1049 if (udc) {
1050 udc->vbus = status;
1051 usb_udc_connect_control(udc);
1052 }
1053 }
1054 EXPORT_SYMBOL_GPL(usb_udc_vbus_handler);
1055
1056 /**
1057 * usb_gadget_udc_reset - notifies the udc core that bus reset occurs
1058 * @gadget: The gadget which bus reset occurs
1059 * @driver: The gadget driver we want to notify
1060 *
1061 * If the udc driver has bus reset handler, it needs to call this when the bus
1062 * reset occurs, it notifies the gadget driver that the bus reset occurs as
1063 * well as updates gadget state.
1064 */
usb_gadget_udc_reset(struct usb_gadget * gadget,struct usb_gadget_driver * driver)1065 void usb_gadget_udc_reset(struct usb_gadget *gadget,
1066 struct usb_gadget_driver *driver)
1067 {
1068 driver->reset(gadget);
1069 usb_gadget_set_state(gadget, USB_STATE_DEFAULT);
1070 }
1071 EXPORT_SYMBOL_GPL(usb_gadget_udc_reset);
1072
1073 /**
1074 * usb_gadget_udc_start - tells usb device controller to start up
1075 * @udc: The UDC to be started
1076 *
1077 * This call is issued by the UDC Class driver when it's about
1078 * to register a gadget driver to the device controller, before
1079 * calling gadget driver's bind() method.
1080 *
1081 * It allows the controller to be powered off until strictly
1082 * necessary to have it powered on.
1083 *
1084 * Returns zero on success, else negative errno.
1085 */
usb_gadget_udc_start(struct usb_udc * udc)1086 static inline int usb_gadget_udc_start(struct usb_udc *udc)
1087 {
1088 return udc->gadget->ops->udc_start(udc->gadget, udc->driver);
1089 }
1090
1091 /**
1092 * usb_gadget_udc_stop - tells usb device controller we don't need it anymore
1093 * @udc: The UDC to be stopped
1094 *
1095 * This call is issued by the UDC Class driver after calling
1096 * gadget driver's unbind() method.
1097 *
1098 * The details are implementation specific, but it can go as
1099 * far as powering off UDC completely and disable its data
1100 * line pullups.
1101 */
usb_gadget_udc_stop(struct usb_udc * udc)1102 static inline void usb_gadget_udc_stop(struct usb_udc *udc)
1103 {
1104 udc->gadget->ops->udc_stop(udc->gadget);
1105 }
1106
1107 /**
1108 * usb_gadget_udc_set_speed - tells usb device controller speed supported by
1109 * current driver
1110 * @udc: The device we want to set maximum speed
1111 * @speed: The maximum speed to allowed to run
1112 *
1113 * This call is issued by the UDC Class driver before calling
1114 * usb_gadget_udc_start() in order to make sure that we don't try to
1115 * connect on speeds the gadget driver doesn't support.
1116 */
usb_gadget_udc_set_speed(struct usb_udc * udc,enum usb_device_speed speed)1117 static inline void usb_gadget_udc_set_speed(struct usb_udc *udc,
1118 enum usb_device_speed speed)
1119 {
1120 if (udc->gadget->ops->udc_set_speed) {
1121 enum usb_device_speed s;
1122
1123 s = min(speed, udc->gadget->max_speed);
1124 udc->gadget->ops->udc_set_speed(udc->gadget, s);
1125 }
1126 }
1127
1128 /**
1129 * usb_udc_release - release the usb_udc struct
1130 * @dev: the dev member within usb_udc
1131 *
1132 * This is called by driver's core in order to free memory once the last
1133 * reference is released.
1134 */
usb_udc_release(struct device * dev)1135 static void usb_udc_release(struct device *dev)
1136 {
1137 struct usb_udc *udc;
1138
1139 udc = container_of(dev, struct usb_udc, dev);
1140 dev_dbg(dev, "releasing '%s'\n", dev_name(dev));
1141 kfree(udc);
1142 }
1143
1144 static const struct attribute_group *usb_udc_attr_groups[];
1145
usb_udc_nop_release(struct device * dev)1146 static void usb_udc_nop_release(struct device *dev)
1147 {
1148 dev_vdbg(dev, "%s\n", __func__);
1149 }
1150
1151 /* should be called with udc_lock held */
check_pending_gadget_drivers(struct usb_udc * udc)1152 static int check_pending_gadget_drivers(struct usb_udc *udc)
1153 {
1154 struct usb_gadget_driver *driver;
1155 int ret = 0;
1156
1157 list_for_each_entry(driver, &gadget_driver_pending_list, pending)
1158 if (!driver->udc_name || strcmp(driver->udc_name,
1159 dev_name(&udc->dev)) == 0) {
1160 ret = udc_bind_to_driver(udc, driver);
1161 if (ret != -EPROBE_DEFER)
1162 list_del_init(&driver->pending);
1163 break;
1164 }
1165
1166 return ret;
1167 }
1168
1169 /**
1170 * usb_initialize_gadget - initialize a gadget and its embedded struct device
1171 * @parent: the parent device to this udc. Usually the controller driver's
1172 * device.
1173 * @gadget: the gadget to be initialized.
1174 * @release: a gadget release function.
1175 *
1176 * Returns zero on success, negative errno otherwise.
1177 * Calls the gadget release function in the latter case.
1178 */
usb_initialize_gadget(struct device * parent,struct usb_gadget * gadget,void (* release)(struct device * dev))1179 void usb_initialize_gadget(struct device *parent, struct usb_gadget *gadget,
1180 void (*release)(struct device *dev))
1181 {
1182 dev_set_name(&gadget->dev, "gadget");
1183 INIT_WORK(&gadget->work, usb_gadget_state_work);
1184 gadget->dev.parent = parent;
1185
1186 if (release)
1187 gadget->dev.release = release;
1188 else
1189 gadget->dev.release = usb_udc_nop_release;
1190
1191 device_initialize(&gadget->dev);
1192 }
1193 EXPORT_SYMBOL_GPL(usb_initialize_gadget);
1194
1195 /**
1196 * usb_add_gadget - adds a new gadget to the udc class driver list
1197 * @gadget: the gadget to be added to the list.
1198 *
1199 * Returns zero on success, negative errno otherwise.
1200 * Does not do a final usb_put_gadget() if an error occurs.
1201 */
usb_add_gadget(struct usb_gadget * gadget)1202 int usb_add_gadget(struct usb_gadget *gadget)
1203 {
1204 struct usb_udc *udc;
1205 int ret = -ENOMEM;
1206
1207 udc = kzalloc(sizeof(*udc), GFP_KERNEL);
1208 if (!udc)
1209 goto error;
1210
1211 device_initialize(&udc->dev);
1212 udc->dev.release = usb_udc_release;
1213 udc->dev.class = udc_class;
1214 udc->dev.groups = usb_udc_attr_groups;
1215 udc->dev.parent = gadget->dev.parent;
1216 ret = dev_set_name(&udc->dev, "%s",
1217 kobject_name(&gadget->dev.parent->kobj));
1218 if (ret)
1219 goto err_put_udc;
1220
1221 ret = device_add(&gadget->dev);
1222 if (ret)
1223 goto err_put_udc;
1224
1225 udc->gadget = gadget;
1226 gadget->udc = udc;
1227
1228 mutex_lock(&udc_lock);
1229 list_add_tail(&udc->list, &udc_list);
1230
1231 ret = device_add(&udc->dev);
1232 if (ret)
1233 goto err_unlist_udc;
1234
1235 usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
1236 udc->vbus = true;
1237
1238 /* pick up one of pending gadget drivers */
1239 ret = check_pending_gadget_drivers(udc);
1240 if (ret)
1241 goto err_del_udc;
1242
1243 mutex_unlock(&udc_lock);
1244
1245 return 0;
1246
1247 err_del_udc:
1248 flush_work(&gadget->work);
1249 device_del(&udc->dev);
1250
1251 err_unlist_udc:
1252 list_del(&udc->list);
1253 mutex_unlock(&udc_lock);
1254
1255 device_del(&gadget->dev);
1256
1257 err_put_udc:
1258 put_device(&udc->dev);
1259
1260 error:
1261 return ret;
1262 }
1263 EXPORT_SYMBOL_GPL(usb_add_gadget);
1264
1265 /**
1266 * usb_add_gadget_udc_release - adds a new gadget to the udc class driver list
1267 * @parent: the parent device to this udc. Usually the controller driver's
1268 * device.
1269 * @gadget: the gadget to be added to the list.
1270 * @release: a gadget release function.
1271 *
1272 * Returns zero on success, negative errno otherwise.
1273 * Calls the gadget release function in the latter case.
1274 */
usb_add_gadget_udc_release(struct device * parent,struct usb_gadget * gadget,void (* release)(struct device * dev))1275 int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
1276 void (*release)(struct device *dev))
1277 {
1278 int ret;
1279
1280 usb_initialize_gadget(parent, gadget, release);
1281 ret = usb_add_gadget(gadget);
1282 if (ret)
1283 usb_put_gadget(gadget);
1284 return ret;
1285 }
1286 EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release);
1287
1288 /**
1289 * usb_get_gadget_udc_name - get the name of the first UDC controller
1290 * This functions returns the name of the first UDC controller in the system.
1291 * Please note that this interface is usefull only for legacy drivers which
1292 * assume that there is only one UDC controller in the system and they need to
1293 * get its name before initialization. There is no guarantee that the UDC
1294 * of the returned name will be still available, when gadget driver registers
1295 * itself.
1296 *
1297 * Returns pointer to string with UDC controller name on success, NULL
1298 * otherwise. Caller should kfree() returned string.
1299 */
usb_get_gadget_udc_name(void)1300 char *usb_get_gadget_udc_name(void)
1301 {
1302 struct usb_udc *udc;
1303 char *name = NULL;
1304
1305 /* For now we take the first available UDC */
1306 mutex_lock(&udc_lock);
1307 list_for_each_entry(udc, &udc_list, list) {
1308 if (!udc->driver) {
1309 name = kstrdup(udc->gadget->name, GFP_KERNEL);
1310 break;
1311 }
1312 }
1313 mutex_unlock(&udc_lock);
1314 return name;
1315 }
1316 EXPORT_SYMBOL_GPL(usb_get_gadget_udc_name);
1317
1318 /**
1319 * usb_add_gadget_udc - adds a new gadget to the udc class driver list
1320 * @parent: the parent device to this udc. Usually the controller
1321 * driver's device.
1322 * @gadget: the gadget to be added to the list
1323 *
1324 * Returns zero on success, negative errno otherwise.
1325 */
usb_add_gadget_udc(struct device * parent,struct usb_gadget * gadget)1326 int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
1327 {
1328 return usb_add_gadget_udc_release(parent, gadget, NULL);
1329 }
1330 EXPORT_SYMBOL_GPL(usb_add_gadget_udc);
1331
usb_gadget_remove_driver(struct usb_udc * udc)1332 static void usb_gadget_remove_driver(struct usb_udc *udc)
1333 {
1334 dev_dbg(&udc->dev, "unregistering UDC driver [%s]\n",
1335 udc->driver->function);
1336
1337 kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
1338
1339 usb_gadget_disconnect(udc->gadget);
1340 if (udc->gadget->irq)
1341 synchronize_irq(udc->gadget->irq);
1342 udc->driver->unbind(udc->gadget);
1343 usb_gadget_udc_stop(udc);
1344
1345 udc->driver = NULL;
1346 udc->dev.driver = NULL;
1347 udc->gadget->dev.driver = NULL;
1348 }
1349
1350 /**
1351 * usb_del_gadget - deletes @udc from udc_list
1352 * @gadget: the gadget to be removed.
1353 *
1354 * This will call usb_gadget_unregister_driver() if
1355 * the @udc is still busy.
1356 * It will not do a final usb_put_gadget().
1357 */
usb_del_gadget(struct usb_gadget * gadget)1358 void usb_del_gadget(struct usb_gadget *gadget)
1359 {
1360 struct usb_udc *udc = gadget->udc;
1361
1362 if (!udc)
1363 return;
1364
1365 dev_vdbg(gadget->dev.parent, "unregistering gadget\n");
1366
1367 mutex_lock(&udc_lock);
1368 list_del(&udc->list);
1369
1370 if (udc->driver) {
1371 struct usb_gadget_driver *driver = udc->driver;
1372
1373 usb_gadget_remove_driver(udc);
1374 list_add(&driver->pending, &gadget_driver_pending_list);
1375 }
1376 mutex_unlock(&udc_lock);
1377
1378 kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
1379 flush_work(&gadget->work);
1380 device_unregister(&udc->dev);
1381 device_del(&gadget->dev);
1382 }
1383 EXPORT_SYMBOL_GPL(usb_del_gadget);
1384
1385 /**
1386 * usb_del_gadget_udc - deletes @udc from udc_list
1387 * @gadget: the gadget to be removed.
1388 *
1389 * Calls usb_del_gadget() and does a final usb_put_gadget().
1390 */
usb_del_gadget_udc(struct usb_gadget * gadget)1391 void usb_del_gadget_udc(struct usb_gadget *gadget)
1392 {
1393 usb_del_gadget(gadget);
1394 usb_put_gadget(gadget);
1395 }
1396 EXPORT_SYMBOL_GPL(usb_del_gadget_udc);
1397
1398 /* ------------------------------------------------------------------------- */
1399
udc_bind_to_driver(struct usb_udc * udc,struct usb_gadget_driver * driver)1400 static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *driver)
1401 {
1402 int ret;
1403
1404 dev_dbg(&udc->dev, "registering UDC driver [%s]\n",
1405 driver->function);
1406
1407 udc->driver = driver;
1408 udc->dev.driver = &driver->driver;
1409 udc->gadget->dev.driver = &driver->driver;
1410
1411 usb_gadget_udc_set_speed(udc, driver->max_speed);
1412
1413 ret = driver->bind(udc->gadget, driver);
1414 if (ret)
1415 goto err1;
1416 ret = usb_gadget_udc_start(udc);
1417 if (ret) {
1418 driver->unbind(udc->gadget);
1419 goto err1;
1420 }
1421 usb_udc_connect_control(udc);
1422
1423 kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
1424 return 0;
1425 err1:
1426 if (ret != -EISNAM)
1427 dev_err(&udc->dev, "failed to start %s: %d\n",
1428 udc->driver->function, ret);
1429 udc->driver = NULL;
1430 udc->dev.driver = NULL;
1431 udc->gadget->dev.driver = NULL;
1432 return ret;
1433 }
1434
usb_gadget_probe_driver(struct usb_gadget_driver * driver)1435 int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
1436 {
1437 struct usb_udc *udc = NULL;
1438 int ret = -ENODEV;
1439
1440 if (!driver || !driver->bind || !driver->setup)
1441 return -EINVAL;
1442
1443 mutex_lock(&udc_lock);
1444 if (driver->udc_name) {
1445 list_for_each_entry(udc, &udc_list, list) {
1446 ret = strcmp(driver->udc_name, dev_name(&udc->dev));
1447 if (!ret)
1448 break;
1449 }
1450 if (ret)
1451 ret = -ENODEV;
1452 else if (udc->driver)
1453 ret = -EBUSY;
1454 else
1455 goto found;
1456 } else {
1457 list_for_each_entry(udc, &udc_list, list) {
1458 /* For now we take the first one */
1459 if (!udc->driver)
1460 goto found;
1461 }
1462 }
1463
1464 if (!driver->match_existing_only) {
1465 list_add_tail(&driver->pending, &gadget_driver_pending_list);
1466 pr_info("udc-core: couldn't find an available UDC - added [%s] to list of pending drivers\n",
1467 driver->function);
1468 ret = 0;
1469 }
1470
1471 mutex_unlock(&udc_lock);
1472 if (ret)
1473 pr_warn("udc-core: couldn't find an available UDC or it's busy\n");
1474 return ret;
1475 found:
1476 ret = udc_bind_to_driver(udc, driver);
1477 mutex_unlock(&udc_lock);
1478 return ret;
1479 }
1480 EXPORT_SYMBOL_GPL(usb_gadget_probe_driver);
1481
usb_gadget_unregister_driver(struct usb_gadget_driver * driver)1482 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
1483 {
1484 struct usb_udc *udc = NULL;
1485 int ret = -ENODEV;
1486
1487 if (!driver || !driver->unbind)
1488 return -EINVAL;
1489
1490 mutex_lock(&udc_lock);
1491 list_for_each_entry(udc, &udc_list, list) {
1492 if (udc->driver == driver) {
1493 usb_gadget_remove_driver(udc);
1494 usb_gadget_set_state(udc->gadget,
1495 USB_STATE_NOTATTACHED);
1496
1497 /* Maybe there is someone waiting for this UDC? */
1498 check_pending_gadget_drivers(udc);
1499 /*
1500 * For now we ignore bind errors as probably it's
1501 * not a valid reason to fail other's gadget unbind
1502 */
1503 ret = 0;
1504 break;
1505 }
1506 }
1507
1508 if (ret) {
1509 list_del(&driver->pending);
1510 ret = 0;
1511 }
1512 mutex_unlock(&udc_lock);
1513 return ret;
1514 }
1515 EXPORT_SYMBOL_GPL(usb_gadget_unregister_driver);
1516
1517 /* ------------------------------------------------------------------------- */
1518
srp_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t n)1519 static ssize_t srp_store(struct device *dev,
1520 struct device_attribute *attr, const char *buf, size_t n)
1521 {
1522 struct usb_udc *udc = container_of(dev, struct usb_udc, dev);
1523
1524 if (sysfs_streq(buf, "1"))
1525 usb_gadget_wakeup(udc->gadget);
1526
1527 return n;
1528 }
1529 static DEVICE_ATTR_WO(srp);
1530
soft_connect_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t n)1531 static ssize_t soft_connect_store(struct device *dev,
1532 struct device_attribute *attr, const char *buf, size_t n)
1533 {
1534 struct usb_udc *udc = container_of(dev, struct usb_udc, dev);
1535 ssize_t ret;
1536
1537 mutex_lock(&udc_lock);
1538 if (!udc->driver) {
1539 dev_err(dev, "soft-connect without a gadget driver\n");
1540 ret = -EOPNOTSUPP;
1541 goto out;
1542 }
1543
1544 if (sysfs_streq(buf, "connect")) {
1545 usb_gadget_udc_start(udc);
1546 usb_gadget_connect(udc->gadget);
1547 } else if (sysfs_streq(buf, "disconnect")) {
1548 usb_gadget_disconnect(udc->gadget);
1549 usb_gadget_udc_stop(udc);
1550 } else {
1551 dev_err(dev, "unsupported command '%s'\n", buf);
1552 ret = -EINVAL;
1553 goto out;
1554 }
1555
1556 ret = n;
1557 out:
1558 mutex_unlock(&udc_lock);
1559 return ret;
1560 }
1561 static DEVICE_ATTR_WO(soft_connect);
1562
state_show(struct device * dev,struct device_attribute * attr,char * buf)1563 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
1564 char *buf)
1565 {
1566 struct usb_udc *udc = container_of(dev, struct usb_udc, dev);
1567 struct usb_gadget *gadget = udc->gadget;
1568
1569 return sprintf(buf, "%s\n", usb_state_string(gadget->state));
1570 }
1571 static DEVICE_ATTR_RO(state);
1572
function_show(struct device * dev,struct device_attribute * attr,char * buf)1573 static ssize_t function_show(struct device *dev, struct device_attribute *attr,
1574 char *buf)
1575 {
1576 struct usb_udc *udc = container_of(dev, struct usb_udc, dev);
1577 struct usb_gadget_driver *drv = udc->driver;
1578
1579 if (!drv || !drv->function)
1580 return 0;
1581 return scnprintf(buf, PAGE_SIZE, "%s\n", drv->function);
1582 }
1583 static DEVICE_ATTR_RO(function);
1584
1585 #define USB_UDC_SPEED_ATTR(name, param) \
1586 ssize_t name##_show(struct device *dev, \
1587 struct device_attribute *attr, char *buf) \
1588 { \
1589 struct usb_udc *udc = container_of(dev, struct usb_udc, dev); \
1590 return scnprintf(buf, PAGE_SIZE, "%s\n", \
1591 usb_speed_string(udc->gadget->param)); \
1592 } \
1593 static DEVICE_ATTR_RO(name)
1594
1595 static USB_UDC_SPEED_ATTR(current_speed, speed);
1596 static USB_UDC_SPEED_ATTR(maximum_speed, max_speed);
1597
1598 #define USB_UDC_ATTR(name) \
1599 ssize_t name##_show(struct device *dev, \
1600 struct device_attribute *attr, char *buf) \
1601 { \
1602 struct usb_udc *udc = container_of(dev, struct usb_udc, dev); \
1603 struct usb_gadget *gadget = udc->gadget; \
1604 \
1605 return scnprintf(buf, PAGE_SIZE, "%d\n", gadget->name); \
1606 } \
1607 static DEVICE_ATTR_RO(name)
1608
1609 static USB_UDC_ATTR(is_otg);
1610 static USB_UDC_ATTR(is_a_peripheral);
1611 static USB_UDC_ATTR(b_hnp_enable);
1612 static USB_UDC_ATTR(a_hnp_support);
1613 static USB_UDC_ATTR(a_alt_hnp_support);
1614 static USB_UDC_ATTR(is_selfpowered);
1615
1616 static struct attribute *usb_udc_attrs[] = {
1617 &dev_attr_srp.attr,
1618 &dev_attr_soft_connect.attr,
1619 &dev_attr_state.attr,
1620 &dev_attr_function.attr,
1621 &dev_attr_current_speed.attr,
1622 &dev_attr_maximum_speed.attr,
1623
1624 &dev_attr_is_otg.attr,
1625 &dev_attr_is_a_peripheral.attr,
1626 &dev_attr_b_hnp_enable.attr,
1627 &dev_attr_a_hnp_support.attr,
1628 &dev_attr_a_alt_hnp_support.attr,
1629 &dev_attr_is_selfpowered.attr,
1630 NULL,
1631 };
1632
1633 static const struct attribute_group usb_udc_attr_group = {
1634 .attrs = usb_udc_attrs,
1635 };
1636
1637 static const struct attribute_group *usb_udc_attr_groups[] = {
1638 &usb_udc_attr_group,
1639 NULL,
1640 };
1641
usb_udc_uevent(struct device * dev,struct kobj_uevent_env * env)1642 static int usb_udc_uevent(struct device *dev, struct kobj_uevent_env *env)
1643 {
1644 struct usb_udc *udc = container_of(dev, struct usb_udc, dev);
1645 int ret;
1646
1647 ret = add_uevent_var(env, "USB_UDC_NAME=%s", udc->gadget->name);
1648 if (ret) {
1649 dev_err(dev, "failed to add uevent USB_UDC_NAME\n");
1650 return ret;
1651 }
1652
1653 if (udc->driver) {
1654 ret = add_uevent_var(env, "USB_UDC_DRIVER=%s",
1655 udc->driver->function);
1656 if (ret) {
1657 dev_err(dev, "failed to add uevent USB_UDC_DRIVER\n");
1658 return ret;
1659 }
1660 }
1661
1662 return 0;
1663 }
1664
usb_udc_init(void)1665 static int __init usb_udc_init(void)
1666 {
1667 udc_class = class_create(THIS_MODULE, "udc");
1668 if (IS_ERR(udc_class)) {
1669 pr_err("failed to create udc class --> %ld\n",
1670 PTR_ERR(udc_class));
1671 return PTR_ERR(udc_class);
1672 }
1673
1674 udc_class->dev_uevent = usb_udc_uevent;
1675 return 0;
1676 }
1677 subsys_initcall(usb_udc_init);
1678
usb_udc_exit(void)1679 static void __exit usb_udc_exit(void)
1680 {
1681 class_destroy(udc_class);
1682 }
1683 module_exit(usb_udc_exit);
1684
1685 MODULE_DESCRIPTION("UDC Framework");
1686 MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
1687 MODULE_LICENSE("GPL v2");
1688