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 
27 static DEFINE_IDA(gadget_id_numbers);
28 
29 static 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  */
44 struct 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 
53 static struct class *udc_class;
54 static LIST_HEAD(udc_list);
55 
56 /* Protects udc_list, udc->driver, driver->is_bound, and related calls */
57 static 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  */
usb_ep_set_maxpacket_limit(struct usb_ep * ep,unsigned maxpacket_limit)69 void 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 }
77 EXPORT_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  */
usb_ep_enable(struct usb_ep * ep)101 int 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 
125 out:
126 	trace_usb_ep_enable(ep, ret);
127 
128 	return ret;
129 }
130 EXPORT_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  */
usb_ep_disable(struct usb_ep * ep)146 int 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 
159 out:
160 	trace_usb_ep_disable(ep, ret);
161 
162 	return ret;
163 }
164 EXPORT_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  */
usb_ep_alloc_request(struct usb_ep * ep,gfp_t gfp_flags)180 struct 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 }
191 EXPORT_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  */
usb_ep_free_request(struct usb_ep * ep,struct usb_request * req)202 void 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 }
208 EXPORT_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  */
usb_ep_queue(struct usb_ep * ep,struct usb_request * req,gfp_t gfp_flags)278 int 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 
290 out:
291 	trace_usb_ep_queue(ep, req, ret);
292 
293 	return ret;
294 }
295 EXPORT_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  */
usb_ep_dequeue(struct usb_ep * ep,struct usb_request * req)314 int 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 }
323 EXPORT_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  */
usb_ep_set_halt(struct usb_ep * ep)348 int 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 }
357 EXPORT_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  */
usb_ep_clear_halt(struct usb_ep * ep)374 int 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 }
383 EXPORT_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  */
usb_ep_set_wedge(struct usb_ep * ep)397 int 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 }
410 EXPORT_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  */
usb_ep_fifo_status(struct usb_ep * ep)429 int 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 }
442 EXPORT_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  */
usb_ep_fifo_flush(struct usb_ep * ep)455 void 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 }
462 EXPORT_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  */
usb_gadget_frame_number(struct usb_gadget * gadget)473 int 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 }
483 EXPORT_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  */
usb_gadget_wakeup(struct usb_gadget * gadget)498 int 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 
509 out:
510 	trace_usb_gadget_wakeup(gadget, ret);
511 
512 	return ret;
513 }
514 EXPORT_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  */
usb_gadget_set_selfpowered(struct usb_gadget * gadget)525 int 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 
536 out:
537 	trace_usb_gadget_set_selfpowered(gadget, ret);
538 
539 	return ret;
540 }
541 EXPORT_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  */
usb_gadget_clear_selfpowered(struct usb_gadget * gadget)553 int 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 
564 out:
565 	trace_usb_gadget_clear_selfpowered(gadget, ret);
566 
567 	return ret;
568 }
569 EXPORT_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  */
usb_gadget_vbus_connect(struct usb_gadget * gadget)584 int 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 
595 out:
596 	trace_usb_gadget_vbus_connect(gadget, ret);
597 
598 	return ret;
599 }
600 EXPORT_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  */
usb_gadget_vbus_draw(struct usb_gadget * gadget,unsigned mA)614 int 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 
627 out:
628 	trace_usb_gadget_vbus_draw(gadget, ret);
629 
630 	return ret;
631 }
632 EXPORT_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  */
usb_gadget_vbus_disconnect(struct usb_gadget * gadget)645 int 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 
656 out:
657 	trace_usb_gadget_vbus_disconnect(gadget, ret);
658 
659 	return ret;
660 }
661 EXPORT_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  */
usb_gadget_connect(struct usb_gadget * gadget)673 int 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 
695 out:
696 	trace_usb_gadget_connect(gadget, ret);
697 
698 	return ret;
699 }
700 EXPORT_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  */
usb_gadget_disconnect(struct usb_gadget * gadget)715 int 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 		mutex_lock(&udc_lock);
740 		if (gadget->udc->driver)
741 			gadget->udc->driver->disconnect(gadget);
742 		mutex_unlock(&udc_lock);
743 	}
744 
745 out:
746 	trace_usb_gadget_disconnect(gadget, ret);
747 
748 	return ret;
749 }
750 EXPORT_SYMBOL_GPL(usb_gadget_disconnect);
751 
752 /**
753  * usb_gadget_deactivate - deactivate function which is not ready to work
754  * @gadget: the peripheral being deactivated
755  *
756  * This routine may be used during the gadget driver bind() call to prevent
757  * the peripheral from ever being visible to the USB host, unless later
758  * usb_gadget_activate() is called.  For example, user mode components may
759  * need to be activated before the system can talk to hosts.
760  *
761  * Returns zero on success, else negative errno.
762  */
usb_gadget_deactivate(struct usb_gadget * gadget)763 int usb_gadget_deactivate(struct usb_gadget *gadget)
764 {
765 	int ret = 0;
766 
767 	if (gadget->deactivated)
768 		goto out;
769 
770 	if (gadget->connected) {
771 		ret = usb_gadget_disconnect(gadget);
772 		if (ret)
773 			goto out;
774 
775 		/*
776 		 * If gadget was being connected before deactivation, we want
777 		 * to reconnect it in usb_gadget_activate().
778 		 */
779 		gadget->connected = true;
780 	}
781 	gadget->deactivated = true;
782 
783 out:
784 	trace_usb_gadget_deactivate(gadget, ret);
785 
786 	return ret;
787 }
788 EXPORT_SYMBOL_GPL(usb_gadget_deactivate);
789 
790 /**
791  * usb_gadget_activate - activate function which is not ready to work
792  * @gadget: the peripheral being activated
793  *
794  * This routine activates gadget which was previously deactivated with
795  * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed.
796  *
797  * Returns zero on success, else negative errno.
798  */
usb_gadget_activate(struct usb_gadget * gadget)799 int usb_gadget_activate(struct usb_gadget *gadget)
800 {
801 	int ret = 0;
802 
803 	if (!gadget->deactivated)
804 		goto out;
805 
806 	gadget->deactivated = false;
807 
808 	/*
809 	 * If gadget has been connected before deactivation, or became connected
810 	 * while it was being deactivated, we call usb_gadget_connect().
811 	 */
812 	if (gadget->connected)
813 		ret = usb_gadget_connect(gadget);
814 
815 out:
816 	trace_usb_gadget_activate(gadget, ret);
817 
818 	return ret;
819 }
820 EXPORT_SYMBOL_GPL(usb_gadget_activate);
821 
822 /* ------------------------------------------------------------------------- */
823 
824 #ifdef	CONFIG_HAS_DMA
825 
usb_gadget_map_request_by_dev(struct device * dev,struct usb_request * req,int is_in)826 int usb_gadget_map_request_by_dev(struct device *dev,
827 		struct usb_request *req, int is_in)
828 {
829 	if (req->length == 0)
830 		return 0;
831 
832 	if (req->num_sgs) {
833 		int     mapped;
834 
835 		mapped = dma_map_sg(dev, req->sg, req->num_sgs,
836 				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
837 		if (mapped == 0) {
838 			dev_err(dev, "failed to map SGs\n");
839 			return -EFAULT;
840 		}
841 
842 		req->num_mapped_sgs = mapped;
843 	} else {
844 		if (is_vmalloc_addr(req->buf)) {
845 			dev_err(dev, "buffer is not dma capable\n");
846 			return -EFAULT;
847 		} else if (object_is_on_stack(req->buf)) {
848 			dev_err(dev, "buffer is on stack\n");
849 			return -EFAULT;
850 		}
851 
852 		req->dma = dma_map_single(dev, req->buf, req->length,
853 				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
854 
855 		if (dma_mapping_error(dev, req->dma)) {
856 			dev_err(dev, "failed to map buffer\n");
857 			return -EFAULT;
858 		}
859 
860 		req->dma_mapped = 1;
861 	}
862 
863 	return 0;
864 }
865 EXPORT_SYMBOL_GPL(usb_gadget_map_request_by_dev);
866 
usb_gadget_map_request(struct usb_gadget * gadget,struct usb_request * req,int is_in)867 int usb_gadget_map_request(struct usb_gadget *gadget,
868 		struct usb_request *req, int is_in)
869 {
870 	return usb_gadget_map_request_by_dev(gadget->dev.parent, req, is_in);
871 }
872 EXPORT_SYMBOL_GPL(usb_gadget_map_request);
873 
usb_gadget_unmap_request_by_dev(struct device * dev,struct usb_request * req,int is_in)874 void usb_gadget_unmap_request_by_dev(struct device *dev,
875 		struct usb_request *req, int is_in)
876 {
877 	if (req->length == 0)
878 		return;
879 
880 	if (req->num_mapped_sgs) {
881 		dma_unmap_sg(dev, req->sg, req->num_sgs,
882 				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
883 
884 		req->num_mapped_sgs = 0;
885 	} else if (req->dma_mapped) {
886 		dma_unmap_single(dev, req->dma, req->length,
887 				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
888 		req->dma_mapped = 0;
889 	}
890 }
891 EXPORT_SYMBOL_GPL(usb_gadget_unmap_request_by_dev);
892 
usb_gadget_unmap_request(struct usb_gadget * gadget,struct usb_request * req,int is_in)893 void usb_gadget_unmap_request(struct usb_gadget *gadget,
894 		struct usb_request *req, int is_in)
895 {
896 	usb_gadget_unmap_request_by_dev(gadget->dev.parent, req, is_in);
897 }
898 EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);
899 
900 #endif	/* CONFIG_HAS_DMA */
901 
902 /* ------------------------------------------------------------------------- */
903 
904 /**
905  * usb_gadget_giveback_request - give the request back to the gadget layer
906  * @ep: the endpoint to be used with with the request
907  * @req: the request being given back
908  *
909  * This is called by device controller drivers in order to return the
910  * completed request back to the gadget layer.
911  */
usb_gadget_giveback_request(struct usb_ep * ep,struct usb_request * req)912 void usb_gadget_giveback_request(struct usb_ep *ep,
913 		struct usb_request *req)
914 {
915 	if (likely(req->status == 0))
916 		usb_led_activity(USB_LED_EVENT_GADGET);
917 
918 	trace_usb_gadget_giveback_request(ep, req, 0);
919 
920 	req->complete(ep, req);
921 }
922 EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
923 
924 /* ------------------------------------------------------------------------- */
925 
926 /**
927  * gadget_find_ep_by_name - returns ep whose name is the same as sting passed
928  *	in second parameter or NULL if searched endpoint not found
929  * @g: controller to check for quirk
930  * @name: name of searched endpoint
931  */
gadget_find_ep_by_name(struct usb_gadget * g,const char * name)932 struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g, const char *name)
933 {
934 	struct usb_ep *ep;
935 
936 	gadget_for_each_ep(ep, g) {
937 		if (!strcmp(ep->name, name))
938 			return ep;
939 	}
940 
941 	return NULL;
942 }
943 EXPORT_SYMBOL_GPL(gadget_find_ep_by_name);
944 
945 /* ------------------------------------------------------------------------- */
946 
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)947 int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
948 		struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
949 		struct usb_ss_ep_comp_descriptor *ep_comp)
950 {
951 	u8		type;
952 	u16		max;
953 	int		num_req_streams = 0;
954 
955 	/* endpoint already claimed? */
956 	if (ep->claimed)
957 		return 0;
958 
959 	type = usb_endpoint_type(desc);
960 	max = usb_endpoint_maxp(desc);
961 
962 	if (usb_endpoint_dir_in(desc) && !ep->caps.dir_in)
963 		return 0;
964 	if (usb_endpoint_dir_out(desc) && !ep->caps.dir_out)
965 		return 0;
966 
967 	if (max > ep->maxpacket_limit)
968 		return 0;
969 
970 	/* "high bandwidth" works only at high speed */
971 	if (!gadget_is_dualspeed(gadget) && usb_endpoint_maxp_mult(desc) > 1)
972 		return 0;
973 
974 	switch (type) {
975 	case USB_ENDPOINT_XFER_CONTROL:
976 		/* only support ep0 for portable CONTROL traffic */
977 		return 0;
978 	case USB_ENDPOINT_XFER_ISOC:
979 		if (!ep->caps.type_iso)
980 			return 0;
981 		/* ISO:  limit 1023 bytes full speed, 1024 high/super speed */
982 		if (!gadget_is_dualspeed(gadget) && max > 1023)
983 			return 0;
984 		break;
985 	case USB_ENDPOINT_XFER_BULK:
986 		if (!ep->caps.type_bulk)
987 			return 0;
988 		if (ep_comp && gadget_is_superspeed(gadget)) {
989 			/* Get the number of required streams from the
990 			 * EP companion descriptor and see if the EP
991 			 * matches it
992 			 */
993 			num_req_streams = ep_comp->bmAttributes & 0x1f;
994 			if (num_req_streams > ep->max_streams)
995 				return 0;
996 		}
997 		break;
998 	case USB_ENDPOINT_XFER_INT:
999 		/* Bulk endpoints handle interrupt transfers,
1000 		 * except the toggle-quirky iso-synch kind
1001 		 */
1002 		if (!ep->caps.type_int && !ep->caps.type_bulk)
1003 			return 0;
1004 		/* INT:  limit 64 bytes full speed, 1024 high/super speed */
1005 		if (!gadget_is_dualspeed(gadget) && max > 64)
1006 			return 0;
1007 		break;
1008 	}
1009 
1010 	return 1;
1011 }
1012 EXPORT_SYMBOL_GPL(usb_gadget_ep_match_desc);
1013 
1014 /**
1015  * usb_gadget_check_config - checks if the UDC can support the binded
1016  *	configuration
1017  * @gadget: controller to check the USB configuration
1018  *
1019  * Ensure that a UDC is able to support the requested resources by a
1020  * configuration, and that there are no resource limitations, such as
1021  * internal memory allocated to all requested endpoints.
1022  *
1023  * Returns zero on success, else a negative errno.
1024  */
usb_gadget_check_config(struct usb_gadget * gadget)1025 int usb_gadget_check_config(struct usb_gadget *gadget)
1026 {
1027 	if (gadget->ops->check_config)
1028 		return gadget->ops->check_config(gadget);
1029 	return 0;
1030 }
1031 EXPORT_SYMBOL_GPL(usb_gadget_check_config);
1032 
1033 /* ------------------------------------------------------------------------- */
1034 
usb_gadget_state_work(struct work_struct * work)1035 static void usb_gadget_state_work(struct work_struct *work)
1036 {
1037 	struct usb_gadget *gadget = work_to_gadget(work);
1038 	struct usb_udc *udc = gadget->udc;
1039 
1040 	if (udc)
1041 		sysfs_notify(&udc->dev.kobj, NULL, "state");
1042 }
1043 
usb_gadget_set_state(struct usb_gadget * gadget,enum usb_device_state state)1044 void usb_gadget_set_state(struct usb_gadget *gadget,
1045 		enum usb_device_state state)
1046 {
1047 	gadget->state = state;
1048 	schedule_work(&gadget->work);
1049 }
1050 EXPORT_SYMBOL_GPL(usb_gadget_set_state);
1051 
1052 /* ------------------------------------------------------------------------- */
1053 
usb_udc_connect_control(struct usb_udc * udc)1054 static void usb_udc_connect_control(struct usb_udc *udc)
1055 {
1056 	if (udc->vbus)
1057 		usb_gadget_connect(udc->gadget);
1058 	else
1059 		usb_gadget_disconnect(udc->gadget);
1060 }
1061 
1062 /**
1063  * usb_udc_vbus_handler - updates the udc core vbus status, and try to
1064  * connect or disconnect gadget
1065  * @gadget: The gadget which vbus change occurs
1066  * @status: The vbus status
1067  *
1068  * The udc driver calls it when it wants to connect or disconnect gadget
1069  * according to vbus status.
1070  */
usb_udc_vbus_handler(struct usb_gadget * gadget,bool status)1071 void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status)
1072 {
1073 	struct usb_udc *udc = gadget->udc;
1074 
1075 	if (udc) {
1076 		udc->vbus = status;
1077 		usb_udc_connect_control(udc);
1078 	}
1079 }
1080 EXPORT_SYMBOL_GPL(usb_udc_vbus_handler);
1081 
1082 /**
1083  * usb_gadget_udc_reset - notifies the udc core that bus reset occurs
1084  * @gadget: The gadget which bus reset occurs
1085  * @driver: The gadget driver we want to notify
1086  *
1087  * If the udc driver has bus reset handler, it needs to call this when the bus
1088  * reset occurs, it notifies the gadget driver that the bus reset occurs as
1089  * well as updates gadget state.
1090  */
usb_gadget_udc_reset(struct usb_gadget * gadget,struct usb_gadget_driver * driver)1091 void usb_gadget_udc_reset(struct usb_gadget *gadget,
1092 		struct usb_gadget_driver *driver)
1093 {
1094 	driver->reset(gadget);
1095 	usb_gadget_set_state(gadget, USB_STATE_DEFAULT);
1096 }
1097 EXPORT_SYMBOL_GPL(usb_gadget_udc_reset);
1098 
1099 /**
1100  * usb_gadget_udc_start - tells usb device controller to start up
1101  * @udc: The UDC to be started
1102  *
1103  * This call is issued by the UDC Class driver when it's about
1104  * to register a gadget driver to the device controller, before
1105  * calling gadget driver's bind() method.
1106  *
1107  * It allows the controller to be powered off until strictly
1108  * necessary to have it powered on.
1109  *
1110  * Returns zero on success, else negative errno.
1111  */
usb_gadget_udc_start(struct usb_udc * udc)1112 static inline int usb_gadget_udc_start(struct usb_udc *udc)
1113 {
1114 	int ret;
1115 
1116 	if (udc->started) {
1117 		dev_err(&udc->dev, "UDC had already started\n");
1118 		return -EBUSY;
1119 	}
1120 
1121 	ret = udc->gadget->ops->udc_start(udc->gadget, udc->driver);
1122 	if (!ret)
1123 		udc->started = true;
1124 
1125 	return ret;
1126 }
1127 
1128 /**
1129  * usb_gadget_udc_stop - tells usb device controller we don't need it anymore
1130  * @udc: The UDC to be stopped
1131  *
1132  * This call is issued by the UDC Class driver after calling
1133  * gadget driver's unbind() method.
1134  *
1135  * The details are implementation specific, but it can go as
1136  * far as powering off UDC completely and disable its data
1137  * line pullups.
1138  */
usb_gadget_udc_stop(struct usb_udc * udc)1139 static inline void usb_gadget_udc_stop(struct usb_udc *udc)
1140 {
1141 	if (!udc->started) {
1142 		dev_err(&udc->dev, "UDC had already stopped\n");
1143 		return;
1144 	}
1145 
1146 	udc->gadget->ops->udc_stop(udc->gadget);
1147 	udc->started = false;
1148 }
1149 
1150 /**
1151  * usb_gadget_udc_set_speed - tells usb device controller speed supported by
1152  *    current driver
1153  * @udc: The device we want to set maximum speed
1154  * @speed: The maximum speed to allowed to run
1155  *
1156  * This call is issued by the UDC Class driver before calling
1157  * usb_gadget_udc_start() in order to make sure that we don't try to
1158  * connect on speeds the gadget driver doesn't support.
1159  */
usb_gadget_udc_set_speed(struct usb_udc * udc,enum usb_device_speed speed)1160 static inline void usb_gadget_udc_set_speed(struct usb_udc *udc,
1161 					    enum usb_device_speed speed)
1162 {
1163 	struct usb_gadget *gadget = udc->gadget;
1164 	enum usb_device_speed s;
1165 
1166 	if (speed == USB_SPEED_UNKNOWN)
1167 		s = gadget->max_speed;
1168 	else
1169 		s = min(speed, gadget->max_speed);
1170 
1171 	if (s == USB_SPEED_SUPER_PLUS && gadget->ops->udc_set_ssp_rate)
1172 		gadget->ops->udc_set_ssp_rate(gadget, gadget->max_ssp_rate);
1173 	else if (gadget->ops->udc_set_speed)
1174 		gadget->ops->udc_set_speed(gadget, s);
1175 }
1176 
1177 /**
1178  * usb_gadget_enable_async_callbacks - tell usb device controller to enable asynchronous callbacks
1179  * @udc: The UDC which should enable async callbacks
1180  *
1181  * This routine is used when binding gadget drivers.  It undoes the effect
1182  * of usb_gadget_disable_async_callbacks(); the UDC driver should enable IRQs
1183  * (if necessary) and resume issuing callbacks.
1184  *
1185  * This routine will always be called in process context.
1186  */
usb_gadget_enable_async_callbacks(struct usb_udc * udc)1187 static inline void usb_gadget_enable_async_callbacks(struct usb_udc *udc)
1188 {
1189 	struct usb_gadget *gadget = udc->gadget;
1190 
1191 	if (gadget->ops->udc_async_callbacks)
1192 		gadget->ops->udc_async_callbacks(gadget, true);
1193 }
1194 
1195 /**
1196  * usb_gadget_disable_async_callbacks - tell usb device controller to disable asynchronous callbacks
1197  * @udc: The UDC which should disable async callbacks
1198  *
1199  * This routine is used when unbinding gadget drivers.  It prevents a race:
1200  * The UDC driver doesn't know when the gadget driver's ->unbind callback
1201  * runs, so unless it is told to disable asynchronous callbacks, it might
1202  * issue a callback (such as ->disconnect) after the unbind has completed.
1203  *
1204  * After this function runs, the UDC driver must suppress all ->suspend,
1205  * ->resume, ->disconnect, ->reset, and ->setup callbacks to the gadget driver
1206  * until async callbacks are again enabled.  A simple-minded but effective
1207  * way to accomplish this is to tell the UDC hardware not to generate any
1208  * more IRQs.
1209  *
1210  * Request completion callbacks must still be issued.  However, it's okay
1211  * to defer them until the request is cancelled, since the pull-up will be
1212  * turned off during the time period when async callbacks are disabled.
1213  *
1214  * This routine will always be called in process context.
1215  */
usb_gadget_disable_async_callbacks(struct usb_udc * udc)1216 static inline void usb_gadget_disable_async_callbacks(struct usb_udc *udc)
1217 {
1218 	struct usb_gadget *gadget = udc->gadget;
1219 
1220 	if (gadget->ops->udc_async_callbacks)
1221 		gadget->ops->udc_async_callbacks(gadget, false);
1222 }
1223 
1224 /**
1225  * usb_udc_release - release the usb_udc struct
1226  * @dev: the dev member within usb_udc
1227  *
1228  * This is called by driver's core in order to free memory once the last
1229  * reference is released.
1230  */
usb_udc_release(struct device * dev)1231 static void usb_udc_release(struct device *dev)
1232 {
1233 	struct usb_udc *udc;
1234 
1235 	udc = container_of(dev, struct usb_udc, dev);
1236 	dev_dbg(dev, "releasing '%s'\n", dev_name(dev));
1237 	kfree(udc);
1238 }
1239 
1240 static const struct attribute_group *usb_udc_attr_groups[];
1241 
usb_udc_nop_release(struct device * dev)1242 static void usb_udc_nop_release(struct device *dev)
1243 {
1244 	dev_vdbg(dev, "%s\n", __func__);
1245 }
1246 
1247 /**
1248  * usb_initialize_gadget - initialize a gadget and its embedded struct device
1249  * @parent: the parent device to this udc. Usually the controller driver's
1250  * device.
1251  * @gadget: the gadget to be initialized.
1252  * @release: a gadget release function.
1253  */
usb_initialize_gadget(struct device * parent,struct usb_gadget * gadget,void (* release)(struct device * dev))1254 void usb_initialize_gadget(struct device *parent, struct usb_gadget *gadget,
1255 		void (*release)(struct device *dev))
1256 {
1257 	INIT_WORK(&gadget->work, usb_gadget_state_work);
1258 	gadget->dev.parent = parent;
1259 
1260 	if (release)
1261 		gadget->dev.release = release;
1262 	else
1263 		gadget->dev.release = usb_udc_nop_release;
1264 
1265 	device_initialize(&gadget->dev);
1266 	gadget->dev.bus = &gadget_bus_type;
1267 }
1268 EXPORT_SYMBOL_GPL(usb_initialize_gadget);
1269 
1270 /**
1271  * usb_add_gadget - adds a new gadget to the udc class driver list
1272  * @gadget: the gadget to be added to the list.
1273  *
1274  * Returns zero on success, negative errno otherwise.
1275  * Does not do a final usb_put_gadget() if an error occurs.
1276  */
usb_add_gadget(struct usb_gadget * gadget)1277 int usb_add_gadget(struct usb_gadget *gadget)
1278 {
1279 	struct usb_udc		*udc;
1280 	int			ret = -ENOMEM;
1281 
1282 	udc = kzalloc(sizeof(*udc), GFP_KERNEL);
1283 	if (!udc)
1284 		goto error;
1285 
1286 	device_initialize(&udc->dev);
1287 	udc->dev.release = usb_udc_release;
1288 	udc->dev.class = udc_class;
1289 	udc->dev.groups = usb_udc_attr_groups;
1290 	udc->dev.parent = gadget->dev.parent;
1291 	ret = dev_set_name(&udc->dev, "%s",
1292 			kobject_name(&gadget->dev.parent->kobj));
1293 	if (ret)
1294 		goto err_put_udc;
1295 
1296 	udc->gadget = gadget;
1297 	gadget->udc = udc;
1298 
1299 	udc->started = false;
1300 
1301 	mutex_lock(&udc_lock);
1302 	list_add_tail(&udc->list, &udc_list);
1303 	mutex_unlock(&udc_lock);
1304 
1305 	ret = device_add(&udc->dev);
1306 	if (ret)
1307 		goto err_unlist_udc;
1308 
1309 	usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
1310 	udc->vbus = true;
1311 
1312 	ret = ida_alloc(&gadget_id_numbers, GFP_KERNEL);
1313 	if (ret < 0)
1314 		goto err_del_udc;
1315 	gadget->id_number = ret;
1316 	dev_set_name(&gadget->dev, "gadget.%d", ret);
1317 
1318 	ret = device_add(&gadget->dev);
1319 	if (ret)
1320 		goto err_free_id;
1321 
1322 	return 0;
1323 
1324  err_free_id:
1325 	ida_free(&gadget_id_numbers, gadget->id_number);
1326 
1327  err_del_udc:
1328 	flush_work(&gadget->work);
1329 	device_del(&udc->dev);
1330 
1331  err_unlist_udc:
1332 	mutex_lock(&udc_lock);
1333 	list_del(&udc->list);
1334 	mutex_unlock(&udc_lock);
1335 
1336  err_put_udc:
1337 	put_device(&udc->dev);
1338 
1339  error:
1340 	return ret;
1341 }
1342 EXPORT_SYMBOL_GPL(usb_add_gadget);
1343 
1344 /**
1345  * usb_add_gadget_udc_release - adds a new gadget to the udc class driver list
1346  * @parent: the parent device to this udc. Usually the controller driver's
1347  * device.
1348  * @gadget: the gadget to be added to the list.
1349  * @release: a gadget release function.
1350  *
1351  * Returns zero on success, negative errno otherwise.
1352  * Calls the gadget release function in the latter case.
1353  */
usb_add_gadget_udc_release(struct device * parent,struct usb_gadget * gadget,void (* release)(struct device * dev))1354 int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
1355 		void (*release)(struct device *dev))
1356 {
1357 	int	ret;
1358 
1359 	usb_initialize_gadget(parent, gadget, release);
1360 	ret = usb_add_gadget(gadget);
1361 	if (ret)
1362 		usb_put_gadget(gadget);
1363 	return ret;
1364 }
1365 EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release);
1366 
1367 /**
1368  * usb_get_gadget_udc_name - get the name of the first UDC controller
1369  * This functions returns the name of the first UDC controller in the system.
1370  * Please note that this interface is usefull only for legacy drivers which
1371  * assume that there is only one UDC controller in the system and they need to
1372  * get its name before initialization. There is no guarantee that the UDC
1373  * of the returned name will be still available, when gadget driver registers
1374  * itself.
1375  *
1376  * Returns pointer to string with UDC controller name on success, NULL
1377  * otherwise. Caller should kfree() returned string.
1378  */
usb_get_gadget_udc_name(void)1379 char *usb_get_gadget_udc_name(void)
1380 {
1381 	struct usb_udc *udc;
1382 	char *name = NULL;
1383 
1384 	/* For now we take the first available UDC */
1385 	mutex_lock(&udc_lock);
1386 	list_for_each_entry(udc, &udc_list, list) {
1387 		if (!udc->driver) {
1388 			name = kstrdup(udc->gadget->name, GFP_KERNEL);
1389 			break;
1390 		}
1391 	}
1392 	mutex_unlock(&udc_lock);
1393 	return name;
1394 }
1395 EXPORT_SYMBOL_GPL(usb_get_gadget_udc_name);
1396 
1397 /**
1398  * usb_add_gadget_udc - adds a new gadget to the udc class driver list
1399  * @parent: the parent device to this udc. Usually the controller
1400  * driver's device.
1401  * @gadget: the gadget to be added to the list
1402  *
1403  * Returns zero on success, negative errno otherwise.
1404  */
usb_add_gadget_udc(struct device * parent,struct usb_gadget * gadget)1405 int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
1406 {
1407 	return usb_add_gadget_udc_release(parent, gadget, NULL);
1408 }
1409 EXPORT_SYMBOL_GPL(usb_add_gadget_udc);
1410 
1411 /**
1412  * usb_del_gadget - deletes a gadget and unregisters its udc
1413  * @gadget: the gadget to be deleted.
1414  *
1415  * This will unbind @gadget, if it is bound.
1416  * It will not do a final usb_put_gadget().
1417  */
usb_del_gadget(struct usb_gadget * gadget)1418 void usb_del_gadget(struct usb_gadget *gadget)
1419 {
1420 	struct usb_udc *udc = gadget->udc;
1421 
1422 	if (!udc)
1423 		return;
1424 
1425 	dev_vdbg(gadget->dev.parent, "unregistering gadget\n");
1426 
1427 	mutex_lock(&udc_lock);
1428 	list_del(&udc->list);
1429 	mutex_unlock(&udc_lock);
1430 
1431 	kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
1432 	flush_work(&gadget->work);
1433 	device_del(&gadget->dev);
1434 	ida_free(&gadget_id_numbers, gadget->id_number);
1435 	device_unregister(&udc->dev);
1436 }
1437 EXPORT_SYMBOL_GPL(usb_del_gadget);
1438 
1439 /**
1440  * usb_del_gadget_udc - unregisters a gadget
1441  * @gadget: the gadget to be unregistered.
1442  *
1443  * Calls usb_del_gadget() and does a final usb_put_gadget().
1444  */
usb_del_gadget_udc(struct usb_gadget * gadget)1445 void usb_del_gadget_udc(struct usb_gadget *gadget)
1446 {
1447 	usb_del_gadget(gadget);
1448 	usb_put_gadget(gadget);
1449 }
1450 EXPORT_SYMBOL_GPL(usb_del_gadget_udc);
1451 
1452 /* ------------------------------------------------------------------------- */
1453 
gadget_match_driver(struct device * dev,struct device_driver * drv)1454 static int gadget_match_driver(struct device *dev, struct device_driver *drv)
1455 {
1456 	struct usb_gadget *gadget = dev_to_usb_gadget(dev);
1457 	struct usb_udc *udc = gadget->udc;
1458 	struct usb_gadget_driver *driver = container_of(drv,
1459 			struct usb_gadget_driver, driver);
1460 
1461 	/* If the driver specifies a udc_name, it must match the UDC's name */
1462 	if (driver->udc_name &&
1463 			strcmp(driver->udc_name, dev_name(&udc->dev)) != 0)
1464 		return 0;
1465 
1466 	/* If the driver is already bound to a gadget, it doesn't match */
1467 	if (driver->is_bound)
1468 		return 0;
1469 
1470 	/* Otherwise any gadget driver matches any UDC */
1471 	return 1;
1472 }
1473 
gadget_bind_driver(struct device * dev)1474 static int gadget_bind_driver(struct device *dev)
1475 {
1476 	struct usb_gadget *gadget = dev_to_usb_gadget(dev);
1477 	struct usb_udc *udc = gadget->udc;
1478 	struct usb_gadget_driver *driver = container_of(dev->driver,
1479 			struct usb_gadget_driver, driver);
1480 	int ret = 0;
1481 
1482 	mutex_lock(&udc_lock);
1483 	if (driver->is_bound) {
1484 		mutex_unlock(&udc_lock);
1485 		return -ENXIO;		/* Driver binds to only one gadget */
1486 	}
1487 	driver->is_bound = true;
1488 	udc->driver = driver;
1489 	mutex_unlock(&udc_lock);
1490 
1491 	dev_dbg(&udc->dev, "binding gadget driver [%s]\n", driver->function);
1492 
1493 	usb_gadget_udc_set_speed(udc, driver->max_speed);
1494 
1495 	ret = driver->bind(udc->gadget, driver);
1496 	if (ret)
1497 		goto err_bind;
1498 
1499 	ret = usb_gadget_udc_start(udc);
1500 	if (ret)
1501 		goto err_start;
1502 	usb_gadget_enable_async_callbacks(udc);
1503 	usb_udc_connect_control(udc);
1504 
1505 	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
1506 	return 0;
1507 
1508  err_start:
1509 	driver->unbind(udc->gadget);
1510 
1511  err_bind:
1512 	if (ret != -EISNAM)
1513 		dev_err(&udc->dev, "failed to start %s: %d\n",
1514 			driver->function, ret);
1515 
1516 	mutex_lock(&udc_lock);
1517 	udc->driver = NULL;
1518 	driver->is_bound = false;
1519 	mutex_unlock(&udc_lock);
1520 
1521 	return ret;
1522 }
1523 
gadget_unbind_driver(struct device * dev)1524 static void gadget_unbind_driver(struct device *dev)
1525 {
1526 	struct usb_gadget *gadget = dev_to_usb_gadget(dev);
1527 	struct usb_udc *udc = gadget->udc;
1528 	struct usb_gadget_driver *driver = udc->driver;
1529 
1530 	dev_dbg(&udc->dev, "unbinding gadget driver [%s]\n", driver->function);
1531 
1532 	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
1533 
1534 	usb_gadget_disconnect(gadget);
1535 	usb_gadget_disable_async_callbacks(udc);
1536 	if (gadget->irq)
1537 		synchronize_irq(gadget->irq);
1538 	udc->driver->unbind(gadget);
1539 	usb_gadget_udc_stop(udc);
1540 
1541 	mutex_lock(&udc_lock);
1542 	driver->is_bound = false;
1543 	udc->driver = NULL;
1544 	mutex_unlock(&udc_lock);
1545 }
1546 
1547 /* ------------------------------------------------------------------------- */
1548 
usb_gadget_register_driver_owner(struct usb_gadget_driver * driver,struct module * owner,const char * mod_name)1549 int usb_gadget_register_driver_owner(struct usb_gadget_driver *driver,
1550 		struct module *owner, const char *mod_name)
1551 {
1552 	int ret;
1553 
1554 	if (!driver || !driver->bind || !driver->setup)
1555 		return -EINVAL;
1556 
1557 	driver->driver.bus = &gadget_bus_type;
1558 	driver->driver.owner = owner;
1559 	driver->driver.mod_name = mod_name;
1560 	ret = driver_register(&driver->driver);
1561 	if (ret) {
1562 		pr_warn("%s: driver registration failed: %d\n",
1563 				driver->function, ret);
1564 		return ret;
1565 	}
1566 
1567 	mutex_lock(&udc_lock);
1568 	if (!driver->is_bound) {
1569 		if (driver->match_existing_only) {
1570 			pr_warn("%s: couldn't find an available UDC or it's busy\n",
1571 					driver->function);
1572 			ret = -EBUSY;
1573 		} else {
1574 			pr_info("%s: couldn't find an available UDC\n",
1575 					driver->function);
1576 			ret = 0;
1577 		}
1578 	}
1579 	mutex_unlock(&udc_lock);
1580 
1581 	if (ret)
1582 		driver_unregister(&driver->driver);
1583 	return ret;
1584 }
1585 EXPORT_SYMBOL_GPL(usb_gadget_register_driver_owner);
1586 
usb_gadget_unregister_driver(struct usb_gadget_driver * driver)1587 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
1588 {
1589 	if (!driver || !driver->unbind)
1590 		return -EINVAL;
1591 
1592 	driver_unregister(&driver->driver);
1593 	return 0;
1594 }
1595 EXPORT_SYMBOL_GPL(usb_gadget_unregister_driver);
1596 
1597 /* ------------------------------------------------------------------------- */
1598 
srp_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t n)1599 static ssize_t srp_store(struct device *dev,
1600 		struct device_attribute *attr, const char *buf, size_t n)
1601 {
1602 	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
1603 
1604 	if (sysfs_streq(buf, "1"))
1605 		usb_gadget_wakeup(udc->gadget);
1606 
1607 	return n;
1608 }
1609 static DEVICE_ATTR_WO(srp);
1610 
soft_connect_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t n)1611 static ssize_t soft_connect_store(struct device *dev,
1612 		struct device_attribute *attr, const char *buf, size_t n)
1613 {
1614 	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
1615 	ssize_t			ret;
1616 
1617 	device_lock(&udc->gadget->dev);
1618 	if (!udc->driver) {
1619 		dev_err(dev, "soft-connect without a gadget driver\n");
1620 		ret = -EOPNOTSUPP;
1621 		goto out;
1622 	}
1623 
1624 	if (sysfs_streq(buf, "connect")) {
1625 		usb_gadget_udc_start(udc);
1626 		usb_gadget_connect(udc->gadget);
1627 	} else if (sysfs_streq(buf, "disconnect")) {
1628 		usb_gadget_disconnect(udc->gadget);
1629 		usb_gadget_udc_stop(udc);
1630 	} else {
1631 		dev_err(dev, "unsupported command '%s'\n", buf);
1632 		ret = -EINVAL;
1633 		goto out;
1634 	}
1635 
1636 	ret = n;
1637 out:
1638 	device_unlock(&udc->gadget->dev);
1639 	return ret;
1640 }
1641 static DEVICE_ATTR_WO(soft_connect);
1642 
state_show(struct device * dev,struct device_attribute * attr,char * buf)1643 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
1644 			  char *buf)
1645 {
1646 	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
1647 	struct usb_gadget	*gadget = udc->gadget;
1648 
1649 	return sprintf(buf, "%s\n", usb_state_string(gadget->state));
1650 }
1651 static DEVICE_ATTR_RO(state);
1652 
function_show(struct device * dev,struct device_attribute * attr,char * buf)1653 static ssize_t function_show(struct device *dev, struct device_attribute *attr,
1654 			     char *buf)
1655 {
1656 	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
1657 	struct usb_gadget_driver *drv;
1658 	int			rc = 0;
1659 
1660 	mutex_lock(&udc_lock);
1661 	drv = udc->driver;
1662 	if (drv && drv->function)
1663 		rc = scnprintf(buf, PAGE_SIZE, "%s\n", drv->function);
1664 	mutex_unlock(&udc_lock);
1665 	return rc;
1666 }
1667 static DEVICE_ATTR_RO(function);
1668 
1669 #define USB_UDC_SPEED_ATTR(name, param)					\
1670 ssize_t name##_show(struct device *dev,					\
1671 		struct device_attribute *attr, char *buf)		\
1672 {									\
1673 	struct usb_udc *udc = container_of(dev, struct usb_udc, dev);	\
1674 	return scnprintf(buf, PAGE_SIZE, "%s\n",			\
1675 			usb_speed_string(udc->gadget->param));		\
1676 }									\
1677 static DEVICE_ATTR_RO(name)
1678 
1679 static USB_UDC_SPEED_ATTR(current_speed, speed);
1680 static USB_UDC_SPEED_ATTR(maximum_speed, max_speed);
1681 
1682 #define USB_UDC_ATTR(name)					\
1683 ssize_t name##_show(struct device *dev,				\
1684 		struct device_attribute *attr, char *buf)	\
1685 {								\
1686 	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev); \
1687 	struct usb_gadget	*gadget = udc->gadget;		\
1688 								\
1689 	return scnprintf(buf, PAGE_SIZE, "%d\n", gadget->name);	\
1690 }								\
1691 static DEVICE_ATTR_RO(name)
1692 
1693 static USB_UDC_ATTR(is_otg);
1694 static USB_UDC_ATTR(is_a_peripheral);
1695 static USB_UDC_ATTR(b_hnp_enable);
1696 static USB_UDC_ATTR(a_hnp_support);
1697 static USB_UDC_ATTR(a_alt_hnp_support);
1698 static USB_UDC_ATTR(is_selfpowered);
1699 
1700 static struct attribute *usb_udc_attrs[] = {
1701 	&dev_attr_srp.attr,
1702 	&dev_attr_soft_connect.attr,
1703 	&dev_attr_state.attr,
1704 	&dev_attr_function.attr,
1705 	&dev_attr_current_speed.attr,
1706 	&dev_attr_maximum_speed.attr,
1707 
1708 	&dev_attr_is_otg.attr,
1709 	&dev_attr_is_a_peripheral.attr,
1710 	&dev_attr_b_hnp_enable.attr,
1711 	&dev_attr_a_hnp_support.attr,
1712 	&dev_attr_a_alt_hnp_support.attr,
1713 	&dev_attr_is_selfpowered.attr,
1714 	NULL,
1715 };
1716 
1717 static const struct attribute_group usb_udc_attr_group = {
1718 	.attrs = usb_udc_attrs,
1719 };
1720 
1721 static const struct attribute_group *usb_udc_attr_groups[] = {
1722 	&usb_udc_attr_group,
1723 	NULL,
1724 };
1725 
usb_udc_uevent(struct device * dev,struct kobj_uevent_env * env)1726 static int usb_udc_uevent(struct device *dev, struct kobj_uevent_env *env)
1727 {
1728 	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
1729 	int			ret;
1730 
1731 	ret = add_uevent_var(env, "USB_UDC_NAME=%s", udc->gadget->name);
1732 	if (ret) {
1733 		dev_err(dev, "failed to add uevent USB_UDC_NAME\n");
1734 		return ret;
1735 	}
1736 
1737 	mutex_lock(&udc_lock);
1738 	if (udc->driver)
1739 		ret = add_uevent_var(env, "USB_UDC_DRIVER=%s",
1740 				udc->driver->function);
1741 	mutex_unlock(&udc_lock);
1742 	if (ret) {
1743 		dev_err(dev, "failed to add uevent USB_UDC_DRIVER\n");
1744 		return ret;
1745 	}
1746 
1747 	return 0;
1748 }
1749 
1750 static struct bus_type gadget_bus_type = {
1751 	.name = "gadget",
1752 	.probe = gadget_bind_driver,
1753 	.remove = gadget_unbind_driver,
1754 	.match = gadget_match_driver,
1755 };
1756 
usb_udc_init(void)1757 static int __init usb_udc_init(void)
1758 {
1759 	int rc;
1760 
1761 	udc_class = class_create(THIS_MODULE, "udc");
1762 	if (IS_ERR(udc_class)) {
1763 		pr_err("failed to create udc class --> %ld\n",
1764 				PTR_ERR(udc_class));
1765 		return PTR_ERR(udc_class);
1766 	}
1767 
1768 	udc_class->dev_uevent = usb_udc_uevent;
1769 
1770 	rc = bus_register(&gadget_bus_type);
1771 	if (rc)
1772 		class_destroy(udc_class);
1773 	return rc;
1774 }
1775 subsys_initcall(usb_udc_init);
1776 
usb_udc_exit(void)1777 static void __exit usb_udc_exit(void)
1778 {
1779 	bus_unregister(&gadget_bus_type);
1780 	class_destroy(udc_class);
1781 }
1782 module_exit(usb_udc_exit);
1783 
1784 MODULE_DESCRIPTION("UDC Framework");
1785 MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
1786 MODULE_LICENSE("GPL v2");
1787