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