1 /*
2 * <linux/usb/gadget.h>
3 *
4 * We call the USB code inside a Linux-based peripheral device a "gadget"
5 * driver, except for the hardware-specific bus glue. One USB host can
6 * master many USB gadgets, but the gadgets are only slaved to one host.
7 *
8 *
9 * (C) Copyright 2002-2004 by David Brownell
10 * All Rights Reserved.
11 *
12 * This software is licensed under the GNU GPL version 2.
13 *
14 * Ported to U-Boot by: Thomas Smits <ts.smits@gmail.com> and
15 * Remy Bohmer <linux@bohmer.net>
16 */
17
18 #ifndef __LINUX_USB_GADGET_H
19 #define __LINUX_USB_GADGET_H
20
21 #include <errno.h>
22 #include <usb.h>
23 #include <linux/compat.h>
24 #include <linux/list.h>
25
26 struct usb_ep;
27
28 /**
29 * struct usb_request - describes one i/o request
30 * @buf: Buffer used for data. Always provide this; some controllers
31 * only use PIO, or don't use DMA for some endpoints.
32 * @dma: DMA address corresponding to 'buf'. If you don't set this
33 * field, and the usb controller needs one, it is responsible
34 * for mapping and unmapping the buffer.
35 * @stream_id: The stream id, when USB3.0 bulk streams are being used
36 * @length: Length of that data
37 * @no_interrupt: If true, hints that no completion irq is needed.
38 * Helpful sometimes with deep request queues that are handled
39 * directly by DMA controllers.
40 * @zero: If true, when writing data, makes the last packet be "short"
41 * by adding a zero length packet as needed;
42 * @short_not_ok: When reading data, makes short packets be
43 * treated as errors (queue stops advancing till cleanup).
44 * @complete: Function called when request completes, so this request and
45 * its buffer may be re-used.
46 * Reads terminate with a short packet, or when the buffer fills,
47 * whichever comes first. When writes terminate, some data bytes
48 * will usually still be in flight (often in a hardware fifo).
49 * Errors (for reads or writes) stop the queue from advancing
50 * until the completion function returns, so that any transfers
51 * invalidated by the error may first be dequeued.
52 * @context: For use by the completion callback
53 * @list: For use by the gadget driver.
54 * @status: Reports completion code, zero or a negative errno.
55 * Normally, faults block the transfer queue from advancing until
56 * the completion callback returns.
57 * Code "-ESHUTDOWN" indicates completion caused by device disconnect,
58 * or when the driver disabled the endpoint.
59 * @actual: Reports bytes transferred to/from the buffer. For reads (OUT
60 * transfers) this may be less than the requested length. If the
61 * short_not_ok flag is set, short reads are treated as errors
62 * even when status otherwise indicates successful completion.
63 * Note that for writes (IN transfers) some data bytes may still
64 * reside in a device-side FIFO when the request is reported as
65 * complete.
66 *
67 * These are allocated/freed through the endpoint they're used with. The
68 * hardware's driver can add extra per-request data to the memory it returns,
69 * which often avoids separate memory allocations (potential failures),
70 * later when the request is queued.
71 *
72 * Request flags affect request handling, such as whether a zero length
73 * packet is written (the "zero" flag), whether a short read should be
74 * treated as an error (blocking request queue advance, the "short_not_ok"
75 * flag), or hinting that an interrupt is not required (the "no_interrupt"
76 * flag, for use with deep request queues).
77 *
78 * Bulk endpoints can use any size buffers, and can also be used for interrupt
79 * transfers. interrupt-only endpoints can be much less functional.
80 *
81 * NOTE: this is analagous to 'struct urb' on the host side, except that
82 * it's thinner and promotes more pre-allocation.
83 */
84
85 struct usb_request {
86 void *buf;
87 unsigned length;
88 dma_addr_t dma;
89
90 unsigned stream_id:16;
91 unsigned no_interrupt:1;
92 unsigned zero:1;
93 unsigned short_not_ok:1;
94
95 void (*complete)(struct usb_ep *ep,
96 struct usb_request *req);
97 void *context;
98 struct list_head list;
99
100 int status;
101 unsigned actual;
102 };
103
104 /*-------------------------------------------------------------------------*/
105
106 /* endpoint-specific parts of the api to the usb controller hardware.
107 * unlike the urb model, (de)multiplexing layers are not required.
108 * (so this api could slash overhead if used on the host side...)
109 *
110 * note that device side usb controllers commonly differ in how many
111 * endpoints they support, as well as their capabilities.
112 */
113 struct usb_ep_ops {
114 int (*enable) (struct usb_ep *ep,
115 const struct usb_endpoint_descriptor *desc);
116 int (*disable) (struct usb_ep *ep);
117
118 struct usb_request *(*alloc_request) (struct usb_ep *ep,
119 gfp_t gfp_flags);
120 void (*free_request) (struct usb_ep *ep, struct usb_request *req);
121
122 int (*queue) (struct usb_ep *ep, struct usb_request *req,
123 gfp_t gfp_flags);
124 int (*dequeue) (struct usb_ep *ep, struct usb_request *req);
125
126 int (*set_halt) (struct usb_ep *ep, int value);
127 int (*set_wedge)(struct usb_ep *ep);
128 int (*fifo_status) (struct usb_ep *ep);
129 void (*fifo_flush) (struct usb_ep *ep);
130 };
131
132 /**
133 * struct usb_ep_caps - endpoint capabilities description
134 * @type_control:Endpoint supports control type (reserved for ep0).
135 * @type_iso:Endpoint supports isochronous transfers.
136 * @type_bulk:Endpoint supports bulk transfers.
137 * @type_int:Endpoint supports interrupt transfers.
138 * @dir_in:Endpoint supports IN direction.
139 * @dir_out:Endpoint supports OUT direction.
140 */
141 struct usb_ep_caps {
142 unsigned type_control:1;
143 unsigned type_iso:1;
144 unsigned type_bulk:1;
145 unsigned type_int:1;
146 unsigned dir_in:1;
147 unsigned dir_out:1;
148 };
149
150 /**
151 * struct usb_ep - device side representation of USB endpoint
152 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk"
153 * @ops: Function pointers used to access hardware-specific operations.
154 * @ep_list:the gadget's ep_list holds all of its endpoints
155 * @caps:The structure describing types and directions supported by endoint.
156 * @maxpacket:The maximum packet size used on this endpoint. The initial
157 * value can sometimes be reduced (hardware allowing), according to
158 * the endpoint descriptor used to configure the endpoint.
159 * @maxpacket_limit:The maximum packet size value which can be handled by this
160 * endpoint. It's set once by UDC driver when endpoint is initialized, and
161 * should not be changed. Should not be confused with maxpacket.
162 * @max_streams: The maximum number of streams supported
163 * by this EP (0 - 16, actual number is 2^n)
164 * @maxburst: the maximum number of bursts supported by this EP (for usb3)
165 * @driver_data:for use by the gadget driver. all other fields are
166 * read-only to gadget drivers.
167 * @desc: endpoint descriptor. This pointer is set before the endpoint is
168 * enabled and remains valid until the endpoint is disabled.
169 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion
170 * descriptor that is used to configure the endpoint
171 *
172 * the bus controller driver lists all the general purpose endpoints in
173 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list,
174 * and is accessed only in response to a driver setup() callback.
175 */
176 struct usb_ep {
177 void *driver_data;
178 const char *name;
179 const struct usb_ep_ops *ops;
180 struct list_head ep_list;
181 struct usb_ep_caps caps;
182 unsigned maxpacket:16;
183 unsigned maxpacket_limit:16;
184 unsigned max_streams:16;
185 unsigned maxburst:5;
186 const struct usb_endpoint_descriptor *desc;
187 const struct usb_ss_ep_comp_descriptor *comp_desc;
188 };
189
190 /*-------------------------------------------------------------------------*/
191
192 /**
193 * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
194 * @ep:the endpoint being configured
195 * @maxpacket_limit:value of maximum packet size limit
196 *
197 * This function shoud be used only in UDC drivers to initialize endpoint
198 * (usually in probe function).
199 */
usb_ep_set_maxpacket_limit(struct usb_ep * ep,unsigned maxpacket_limit)200 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
201 unsigned maxpacket_limit)
202 {
203 ep->maxpacket_limit = maxpacket_limit;
204 ep->maxpacket = maxpacket_limit;
205 }
206
207 /**
208 * usb_ep_enable - configure endpoint, making it usable
209 * @ep:the endpoint being configured. may not be the endpoint named "ep0".
210 * drivers discover endpoints through the ep_list of a usb_gadget.
211 * @desc:descriptor for desired behavior. caller guarantees this pointer
212 * remains valid until the endpoint is disabled; the data byte order
213 * is little-endian (usb-standard).
214 *
215 * when configurations are set, or when interface settings change, the driver
216 * will enable or disable the relevant endpoints. while it is enabled, an
217 * endpoint may be used for i/o until the driver receives a disconnect() from
218 * the host or until the endpoint is disabled.
219 *
220 * the ep0 implementation (which calls this routine) must ensure that the
221 * hardware capabilities of each endpoint match the descriptor provided
222 * for it. for example, an endpoint named "ep2in-bulk" would be usable
223 * for interrupt transfers as well as bulk, but it likely couldn't be used
224 * for iso transfers or for endpoint 14. some endpoints are fully
225 * configurable, with more generic names like "ep-a". (remember that for
226 * USB, "in" means "towards the USB master".)
227 *
228 * returns zero, or a negative error code.
229 */
usb_ep_enable(struct usb_ep * ep,const struct usb_endpoint_descriptor * desc)230 static inline int usb_ep_enable(struct usb_ep *ep,
231 const struct usb_endpoint_descriptor *desc)
232 {
233 return ep->ops->enable(ep, desc);
234 }
235
236 /**
237 * usb_ep_disable - endpoint is no longer usable
238 * @ep:the endpoint being unconfigured. may not be the endpoint named "ep0".
239 *
240 * no other task may be using this endpoint when this is called.
241 * any pending and uncompleted requests will complete with status
242 * indicating disconnect (-ESHUTDOWN) before this call returns.
243 * gadget drivers must call usb_ep_enable() again before queueing
244 * requests to the endpoint.
245 *
246 * returns zero, or a negative error code.
247 */
usb_ep_disable(struct usb_ep * ep)248 static inline int usb_ep_disable(struct usb_ep *ep)
249 {
250 return ep->ops->disable(ep);
251 }
252
253 /**
254 * usb_ep_alloc_request - allocate a request object to use with this endpoint
255 * @ep:the endpoint to be used with with the request
256 * @gfp_flags:GFP_* flags to use
257 *
258 * Request objects must be allocated with this call, since they normally
259 * need controller-specific setup and may even need endpoint-specific
260 * resources such as allocation of DMA descriptors.
261 * Requests may be submitted with usb_ep_queue(), and receive a single
262 * completion callback. Free requests with usb_ep_free_request(), when
263 * they are no longer needed.
264 *
265 * Returns the request, or null if one could not be allocated.
266 */
usb_ep_alloc_request(struct usb_ep * ep,gfp_t gfp_flags)267 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
268 gfp_t gfp_flags)
269 {
270 return ep->ops->alloc_request(ep, gfp_flags);
271 }
272
273 /**
274 * usb_ep_free_request - frees a request object
275 * @ep:the endpoint associated with the request
276 * @req:the request being freed
277 *
278 * Reverses the effect of usb_ep_alloc_request().
279 * Caller guarantees the request is not queued, and that it will
280 * no longer be requeued (or otherwise used).
281 */
usb_ep_free_request(struct usb_ep * ep,struct usb_request * req)282 static inline void usb_ep_free_request(struct usb_ep *ep,
283 struct usb_request *req)
284 {
285 ep->ops->free_request(ep, req);
286 }
287
288 /**
289 * usb_ep_queue - queues (submits) an I/O request to an endpoint.
290 * @ep:the endpoint associated with the request
291 * @req:the request being submitted
292 * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
293 * pre-allocate all necessary memory with the request.
294 *
295 * This tells the device controller to perform the specified request through
296 * that endpoint (reading or writing a buffer). When the request completes,
297 * including being canceled by usb_ep_dequeue(), the request's completion
298 * routine is called to return the request to the driver. Any endpoint
299 * (except control endpoints like ep0) may have more than one transfer
300 * request queued; they complete in FIFO order. Once a gadget driver
301 * submits a request, that request may not be examined or modified until it
302 * is given back to that driver through the completion callback.
303 *
304 * Each request is turned into one or more packets. The controller driver
305 * never merges adjacent requests into the same packet. OUT transfers
306 * will sometimes use data that's already buffered in the hardware.
307 * Drivers can rely on the fact that the first byte of the request's buffer
308 * always corresponds to the first byte of some USB packet, for both
309 * IN and OUT transfers.
310 *
311 * Bulk endpoints can queue any amount of data; the transfer is packetized
312 * automatically. The last packet will be short if the request doesn't fill it
313 * out completely. Zero length packets (ZLPs) should be avoided in portable
314 * protocols since not all usb hardware can successfully handle zero length
315 * packets. (ZLPs may be explicitly written, and may be implicitly written if
316 * the request 'zero' flag is set.) Bulk endpoints may also be used
317 * for interrupt transfers; but the reverse is not true, and some endpoints
318 * won't support every interrupt transfer. (Such as 768 byte packets.)
319 *
320 * Interrupt-only endpoints are less functional than bulk endpoints, for
321 * example by not supporting queueing or not handling buffers that are
322 * larger than the endpoint's maxpacket size. They may also treat data
323 * toggle differently.
324 *
325 * Control endpoints ... after getting a setup() callback, the driver queues
326 * one response (even if it would be zero length). That enables the
327 * status ack, after transfering data as specified in the response. Setup
328 * functions may return negative error codes to generate protocol stalls.
329 * (Note that some USB device controllers disallow protocol stall responses
330 * in some cases.) When control responses are deferred (the response is
331 * written after the setup callback returns), then usb_ep_set_halt() may be
332 * used on ep0 to trigger protocol stalls.
333 *
334 * For periodic endpoints, like interrupt or isochronous ones, the usb host
335 * arranges to poll once per interval, and the gadget driver usually will
336 * have queued some data to transfer at that time.
337 *
338 * Returns zero, or a negative error code. Endpoints that are not enabled
339 * report errors; errors will also be
340 * reported when the usb peripheral is disconnected.
341 */
usb_ep_queue(struct usb_ep * ep,struct usb_request * req,gfp_t gfp_flags)342 static inline int usb_ep_queue(struct usb_ep *ep,
343 struct usb_request *req, gfp_t gfp_flags)
344 {
345 return ep->ops->queue(ep, req, gfp_flags);
346 }
347
348 /**
349 * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
350 * @ep:the endpoint associated with the request
351 * @req:the request being canceled
352 *
353 * if the request is still active on the endpoint, it is dequeued and its
354 * completion routine is called (with status -ECONNRESET); else a negative
355 * error code is returned.
356 *
357 * note that some hardware can't clear out write fifos (to unlink the request
358 * at the head of the queue) except as part of disconnecting from usb. such
359 * restrictions prevent drivers from supporting configuration changes,
360 * even to configuration zero (a "chapter 9" requirement).
361 */
usb_ep_dequeue(struct usb_ep * ep,struct usb_request * req)362 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
363 {
364 return ep->ops->dequeue(ep, req);
365 }
366
367 /**
368 * usb_ep_set_halt - sets the endpoint halt feature.
369 * @ep: the non-isochronous endpoint being stalled
370 *
371 * Use this to stall an endpoint, perhaps as an error report.
372 * Except for control endpoints,
373 * the endpoint stays halted (will not stream any data) until the host
374 * clears this feature; drivers may need to empty the endpoint's request
375 * queue first, to make sure no inappropriate transfers happen.
376 *
377 * Note that while an endpoint CLEAR_FEATURE will be invisible to the
378 * gadget driver, a SET_INTERFACE will not be. To reset endpoints for the
379 * current altsetting, see usb_ep_clear_halt(). When switching altsettings,
380 * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
381 *
382 * Returns zero, or a negative error code. On success, this call sets
383 * underlying hardware state that blocks data transfers.
384 * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
385 * transfer requests are still queued, or if the controller hardware
386 * (usually a FIFO) still holds bytes that the host hasn't collected.
387 */
usb_ep_set_halt(struct usb_ep * ep)388 static inline int usb_ep_set_halt(struct usb_ep *ep)
389 {
390 return ep->ops->set_halt(ep, 1);
391 }
392
393 /**
394 * usb_ep_clear_halt - clears endpoint halt, and resets toggle
395 * @ep:the bulk or interrupt endpoint being reset
396 *
397 * Use this when responding to the standard usb "set interface" request,
398 * for endpoints that aren't reconfigured, after clearing any other state
399 * in the endpoint's i/o queue.
400 *
401 * Returns zero, or a negative error code. On success, this call clears
402 * the underlying hardware state reflecting endpoint halt and data toggle.
403 * Note that some hardware can't support this request (like pxa2xx_udc),
404 * and accordingly can't correctly implement interface altsettings.
405 */
usb_ep_clear_halt(struct usb_ep * ep)406 static inline int usb_ep_clear_halt(struct usb_ep *ep)
407 {
408 return ep->ops->set_halt(ep, 0);
409 }
410
411 /**
412 * usb_ep_fifo_status - returns number of bytes in fifo, or error
413 * @ep: the endpoint whose fifo status is being checked.
414 *
415 * FIFO endpoints may have "unclaimed data" in them in certain cases,
416 * such as after aborted transfers. Hosts may not have collected all
417 * the IN data written by the gadget driver (and reported by a request
418 * completion). The gadget driver may not have collected all the data
419 * written OUT to it by the host. Drivers that need precise handling for
420 * fault reporting or recovery may need to use this call.
421 *
422 * This returns the number of such bytes in the fifo, or a negative
423 * errno if the endpoint doesn't use a FIFO or doesn't support such
424 * precise handling.
425 */
usb_ep_fifo_status(struct usb_ep * ep)426 static inline int usb_ep_fifo_status(struct usb_ep *ep)
427 {
428 if (ep->ops->fifo_status)
429 return ep->ops->fifo_status(ep);
430 else
431 return -EOPNOTSUPP;
432 }
433
434 /**
435 * usb_ep_fifo_flush - flushes contents of a fifo
436 * @ep: the endpoint whose fifo is being flushed.
437 *
438 * This call may be used to flush the "unclaimed data" that may exist in
439 * an endpoint fifo after abnormal transaction terminations. The call
440 * must never be used except when endpoint is not being used for any
441 * protocol translation.
442 */
usb_ep_fifo_flush(struct usb_ep * ep)443 static inline void usb_ep_fifo_flush(struct usb_ep *ep)
444 {
445 if (ep->ops->fifo_flush)
446 ep->ops->fifo_flush(ep);
447 }
448
449
450 /*-------------------------------------------------------------------------*/
451
452 struct usb_gadget;
453 struct usb_gadget_driver;
454
455 /* the rest of the api to the controller hardware: device operations,
456 * which don't involve endpoints (or i/o).
457 */
458 struct usb_gadget_ops {
459 int (*get_frame)(struct usb_gadget *);
460 int (*wakeup)(struct usb_gadget *);
461 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
462 int (*vbus_session) (struct usb_gadget *, int is_active);
463 int (*vbus_draw) (struct usb_gadget *, unsigned mA);
464 int (*pullup) (struct usb_gadget *, int is_on);
465 int (*ioctl)(struct usb_gadget *,
466 unsigned code, unsigned long param);
467 int (*udc_start)(struct usb_gadget *,
468 struct usb_gadget_driver *);
469 int (*udc_stop)(struct usb_gadget *);
470 struct usb_ep *(*match_ep)(struct usb_gadget *,
471 struct usb_endpoint_descriptor *,
472 struct usb_ss_ep_comp_descriptor *);
473 void (*udc_set_speed)(struct usb_gadget *gadget,
474 enum usb_device_speed);
475 };
476
477 /**
478 * struct usb_gadget - represents a usb slave device
479 * @ops: Function pointers used to access hardware-specific operations.
480 * @ep0: Endpoint zero, used when reading or writing responses to
481 * driver setup() requests
482 * @ep_list: List of other endpoints supported by the device.
483 * @speed: Speed of current connection to USB host.
484 * @max_speed: Maximal speed the UDC can handle. UDC must support this
485 * and all slower speeds.
486 * @is_dualspeed: true if the controller supports both high and full speed
487 * operation. If it does, the gadget driver must also support both.
488 * @is_otg: true if the USB device port uses a Mini-AB jack, so that the
489 * gadget driver must provide a USB OTG descriptor.
490 * @is_a_peripheral: false unless is_otg, the "A" end of a USB cable
491 * is in the Mini-AB jack, and HNP has been used to switch roles
492 * so that the "A" device currently acts as A-Peripheral, not A-Host.
493 * @a_hnp_support: OTG device feature flag, indicating that the A-Host
494 * supports HNP at this port.
495 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
496 * only supports HNP on a different root port.
497 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
498 * enabled HNP support.
499 * @name: Identifies the controller hardware type. Used in diagnostics
500 * and sometimes configuration.
501 * @dev: Driver model state for this abstract device.
502 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
503 * MaxPacketSize.
504 *
505 * Gadgets have a mostly-portable "gadget driver" implementing device
506 * functions, handling all usb configurations and interfaces. Gadget
507 * drivers talk to hardware-specific code indirectly, through ops vectors.
508 * That insulates the gadget driver from hardware details, and packages
509 * the hardware endpoints through generic i/o queues. The "usb_gadget"
510 * and "usb_ep" interfaces provide that insulation from the hardware.
511 *
512 * Except for the driver data, all fields in this structure are
513 * read-only to the gadget driver. That driver data is part of the
514 * "driver model" infrastructure in 2.6 (and later) kernels, and for
515 * earlier systems is grouped in a similar structure that's not known
516 * to the rest of the kernel.
517 *
518 * Values of the three OTG device feature flags are updated before the
519 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
520 * driver suspend() calls. They are valid only when is_otg, and when the
521 * device is acting as a B-Peripheral (so is_a_peripheral is false).
522 */
523 struct usb_gadget {
524 /* readonly to gadget driver */
525 const struct usb_gadget_ops *ops;
526 struct usb_ep *ep0;
527 struct list_head ep_list; /* of usb_ep */
528 enum usb_device_speed speed;
529 enum usb_device_speed max_speed;
530 enum usb_device_state state;
531 unsigned is_dualspeed:1;
532 unsigned is_otg:1;
533 unsigned is_a_peripheral:1;
534 unsigned b_hnp_enable:1;
535 unsigned a_hnp_support:1;
536 unsigned a_alt_hnp_support:1;
537 const char *name;
538 struct device dev;
539 unsigned quirk_ep_out_aligned_size:1;
540 };
541
set_gadget_data(struct usb_gadget * gadget,void * data)542 static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
543 {
544 gadget->dev.driver_data = data;
545 }
546
get_gadget_data(struct usb_gadget * gadget)547 static inline void *get_gadget_data(struct usb_gadget *gadget)
548 {
549 return gadget->dev.driver_data;
550 }
551
dev_to_usb_gadget(struct device * dev)552 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
553 {
554 return container_of(dev, struct usb_gadget, dev);
555 }
556
557 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
558 #define gadget_for_each_ep(tmp, gadget) \
559 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
560
561
562 /**
563 * gadget_is_dualspeed - return true iff the hardware handles high speed
564 * @g: controller that might support both high and full speeds
565 */
gadget_is_dualspeed(struct usb_gadget * g)566 static inline int gadget_is_dualspeed(struct usb_gadget *g)
567 {
568 #ifdef CONFIG_USB_GADGET_DUALSPEED
569 /* runtime test would check "g->is_dualspeed" ... that might be
570 * useful to work around hardware bugs, but is mostly pointless
571 */
572 return 1;
573 #else
574 return 0;
575 #endif
576 }
577
578 /**
579 * gadget_is_otg - return true iff the hardware is OTG-ready
580 * @g: controller that might have a Mini-AB connector
581 *
582 * This is a runtime test, since kernels with a USB-OTG stack sometimes
583 * run on boards which only have a Mini-B (or Mini-A) connector.
584 */
gadget_is_otg(struct usb_gadget * g)585 static inline int gadget_is_otg(struct usb_gadget *g)
586 {
587 #ifdef CONFIG_USB_OTG
588 return g->is_otg;
589 #else
590 return 0;
591 #endif
592 }
593
594 /**
595 * gadget_is_superspeed() - return true if the hardware handles superspeed
596 * @g: controller that might support superspeed
597 */
gadget_is_superspeed(struct usb_gadget * g)598 static inline int gadget_is_superspeed(struct usb_gadget *g)
599 {
600 return g->max_speed >= USB_SPEED_SUPER;
601 }
602
603 /**
604 * usb_gadget_frame_number - returns the current frame number
605 * @gadget: controller that reports the frame number
606 *
607 * Returns the usb frame number, normally eleven bits from a SOF packet,
608 * or negative errno if this device doesn't support this capability.
609 */
usb_gadget_frame_number(struct usb_gadget * gadget)610 static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
611 {
612 return gadget->ops->get_frame(gadget);
613 }
614
615 /**
616 * usb_gadget_wakeup - tries to wake up the host connected to this gadget
617 * @gadget: controller used to wake up the host
618 *
619 * Returns zero on success, else negative error code if the hardware
620 * doesn't support such attempts, or its support has not been enabled
621 * by the usb host. Drivers must return device descriptors that report
622 * their ability to support this, or hosts won't enable it.
623 *
624 * This may also try to use SRP to wake the host and start enumeration,
625 * even if OTG isn't otherwise in use. OTG devices may also start
626 * remote wakeup even when hosts don't explicitly enable it.
627 */
usb_gadget_wakeup(struct usb_gadget * gadget)628 static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
629 {
630 if (!gadget->ops->wakeup)
631 return -EOPNOTSUPP;
632 return gadget->ops->wakeup(gadget);
633 }
634
635 /**
636 * usb_gadget_set_selfpowered - sets the device selfpowered feature.
637 * @gadget:the device being declared as self-powered
638 *
639 * this affects the device status reported by the hardware driver
640 * to reflect that it now has a local power supply.
641 *
642 * returns zero on success, else negative errno.
643 */
usb_gadget_set_selfpowered(struct usb_gadget * gadget)644 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
645 {
646 if (!gadget->ops->set_selfpowered)
647 return -EOPNOTSUPP;
648 return gadget->ops->set_selfpowered(gadget, 1);
649 }
650
651 /**
652 * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
653 * @gadget:the device being declared as bus-powered
654 *
655 * this affects the device status reported by the hardware driver.
656 * some hardware may not support bus-powered operation, in which
657 * case this feature's value can never change.
658 *
659 * returns zero on success, else negative errno.
660 */
usb_gadget_clear_selfpowered(struct usb_gadget * gadget)661 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
662 {
663 if (!gadget->ops->set_selfpowered)
664 return -EOPNOTSUPP;
665 return gadget->ops->set_selfpowered(gadget, 0);
666 }
667
668 /**
669 * usb_gadget_vbus_connect - Notify controller that VBUS is powered
670 * @gadget:The device which now has VBUS power.
671 *
672 * This call is used by a driver for an external transceiver (or GPIO)
673 * that detects a VBUS power session starting. Common responses include
674 * resuming the controller, activating the D+ (or D-) pullup to let the
675 * host detect that a USB device is attached, and starting to draw power
676 * (8mA or possibly more, especially after SET_CONFIGURATION).
677 *
678 * Returns zero on success, else negative errno.
679 */
usb_gadget_vbus_connect(struct usb_gadget * gadget)680 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
681 {
682 if (!gadget->ops->vbus_session)
683 return -EOPNOTSUPP;
684 return gadget->ops->vbus_session(gadget, 1);
685 }
686
687 /**
688 * usb_gadget_vbus_draw - constrain controller's VBUS power usage
689 * @gadget:The device whose VBUS usage is being described
690 * @mA:How much current to draw, in milliAmperes. This should be twice
691 * the value listed in the configuration descriptor bMaxPower field.
692 *
693 * This call is used by gadget drivers during SET_CONFIGURATION calls,
694 * reporting how much power the device may consume. For example, this
695 * could affect how quickly batteries are recharged.
696 *
697 * Returns zero on success, else negative errno.
698 */
usb_gadget_vbus_draw(struct usb_gadget * gadget,unsigned mA)699 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
700 {
701 if (!gadget->ops->vbus_draw)
702 return -EOPNOTSUPP;
703 return gadget->ops->vbus_draw(gadget, mA);
704 }
705
706 /**
707 * usb_gadget_vbus_disconnect - notify controller about VBUS session end
708 * @gadget:the device whose VBUS supply is being described
709 *
710 * This call is used by a driver for an external transceiver (or GPIO)
711 * that detects a VBUS power session ending. Common responses include
712 * reversing everything done in usb_gadget_vbus_connect().
713 *
714 * Returns zero on success, else negative errno.
715 */
usb_gadget_vbus_disconnect(struct usb_gadget * gadget)716 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
717 {
718 if (!gadget->ops->vbus_session)
719 return -EOPNOTSUPP;
720 return gadget->ops->vbus_session(gadget, 0);
721 }
722
723 /**
724 * usb_gadget_connect - software-controlled connect to USB host
725 * @gadget:the peripheral being connected
726 *
727 * Enables the D+ (or potentially D-) pullup. The host will start
728 * enumerating this gadget when the pullup is active and a VBUS session
729 * is active (the link is powered). This pullup is always enabled unless
730 * usb_gadget_disconnect() has been used to disable it.
731 *
732 * Returns zero on success, else negative errno.
733 */
usb_gadget_connect(struct usb_gadget * gadget)734 static inline int usb_gadget_connect(struct usb_gadget *gadget)
735 {
736 if (!gadget->ops->pullup)
737 return -EOPNOTSUPP;
738 return gadget->ops->pullup(gadget, 1);
739 }
740
741 /**
742 * usb_gadget_disconnect - software-controlled disconnect from USB host
743 * @gadget:the peripheral being disconnected
744 *
745 * Disables the D+ (or potentially D-) pullup, which the host may see
746 * as a disconnect (when a VBUS session is active). Not all systems
747 * support software pullup controls.
748 *
749 * This routine may be used during the gadget driver bind() call to prevent
750 * the peripheral from ever being visible to the USB host, unless later
751 * usb_gadget_connect() is called. For example, user mode components may
752 * need to be activated before the system can talk to hosts.
753 *
754 * Returns zero on success, else negative errno.
755 */
usb_gadget_disconnect(struct usb_gadget * gadget)756 static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
757 {
758 if (!gadget->ops->pullup)
759 return -EOPNOTSUPP;
760 return gadget->ops->pullup(gadget, 0);
761 }
762
763
764 /*-------------------------------------------------------------------------*/
765
766 /**
767 * struct usb_gadget_driver - driver for usb 'slave' devices
768 * @function: String describing the gadget's function
769 * @speed: Highest speed the driver handles.
770 * @bind: Invoked when the driver is bound to a gadget, usually
771 * after registering the driver.
772 * At that point, ep0 is fully initialized, and ep_list holds
773 * the currently-available endpoints.
774 * Called in a context that permits sleeping.
775 * @setup: Invoked for ep0 control requests that aren't handled by
776 * the hardware level driver. Most calls must be handled by
777 * the gadget driver, including descriptor and configuration
778 * management. The 16 bit members of the setup data are in
779 * USB byte order. Called in_interrupt; this may not sleep. Driver
780 * queues a response to ep0, or returns negative to stall.
781 * @disconnect: Invoked after all transfers have been stopped,
782 * when the host is disconnected. May be called in_interrupt; this
783 * may not sleep. Some devices can't detect disconnect, so this might
784 * not be called except as part of controller shutdown.
785 * @unbind: Invoked when the driver is unbound from a gadget,
786 * usually from rmmod (after a disconnect is reported).
787 * Called in a context that permits sleeping.
788 * @suspend: Invoked on USB suspend. May be called in_interrupt.
789 * @resume: Invoked on USB resume. May be called in_interrupt.
790 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers
791 * and should be called in_interrupt.
792 *
793 * Devices are disabled till a gadget driver successfully bind()s, which
794 * means the driver will handle setup() requests needed to enumerate (and
795 * meet "chapter 9" requirements) then do some useful work.
796 *
797 * If gadget->is_otg is true, the gadget driver must provide an OTG
798 * descriptor during enumeration, or else fail the bind() call. In such
799 * cases, no USB traffic may flow until both bind() returns without
800 * having called usb_gadget_disconnect(), and the USB host stack has
801 * initialized.
802 *
803 * Drivers use hardware-specific knowledge to configure the usb hardware.
804 * endpoint addressing is only one of several hardware characteristics that
805 * are in descriptors the ep0 implementation returns from setup() calls.
806 *
807 * Except for ep0 implementation, most driver code shouldn't need change to
808 * run on top of different usb controllers. It'll use endpoints set up by
809 * that ep0 implementation.
810 *
811 * The usb controller driver handles a few standard usb requests. Those
812 * include set_address, and feature flags for devices, interfaces, and
813 * endpoints (the get_status, set_feature, and clear_feature requests).
814 *
815 * Accordingly, the driver's setup() callback must always implement all
816 * get_descriptor requests, returning at least a device descriptor and
817 * a configuration descriptor. Drivers must make sure the endpoint
818 * descriptors match any hardware constraints. Some hardware also constrains
819 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
820 *
821 * The driver's setup() callback must also implement set_configuration,
822 * and should also implement set_interface, get_configuration, and
823 * get_interface. Setting a configuration (or interface) is where
824 * endpoints should be activated or (config 0) shut down.
825 *
826 * (Note that only the default control endpoint is supported. Neither
827 * hosts nor devices generally support control traffic except to ep0.)
828 *
829 * Most devices will ignore USB suspend/resume operations, and so will
830 * not provide those callbacks. However, some may need to change modes
831 * when the host is not longer directing those activities. For example,
832 * local controls (buttons, dials, etc) may need to be re-enabled since
833 * the (remote) host can't do that any longer; or an error state might
834 * be cleared, to make the device behave identically whether or not
835 * power is maintained.
836 */
837 struct usb_gadget_driver {
838 char *function;
839 enum usb_device_speed speed;
840 int (*bind)(struct usb_gadget *);
841 void (*unbind)(struct usb_gadget *);
842 int (*setup)(struct usb_gadget *,
843 const struct usb_ctrlrequest *);
844 void (*disconnect)(struct usb_gadget *);
845 void (*suspend)(struct usb_gadget *);
846 void (*resume)(struct usb_gadget *);
847 void (*reset)(struct usb_gadget *);
848 };
849
850
851 /*-------------------------------------------------------------------------*/
852
853 /* driver modules register and unregister, as usual.
854 * these calls must be made in a context that can sleep.
855 *
856 * these will usually be implemented directly by the hardware-dependent
857 * usb bus interface driver, which will only support a single driver.
858 */
859
860 /**
861 * usb_gadget_register_driver - register a gadget driver
862 * @driver:the driver being registered
863 *
864 * Call this in your gadget driver's module initialization function,
865 * to tell the underlying usb controller driver about your driver.
866 * The driver's bind() function will be called to bind it to a
867 * gadget before this registration call returns. It's expected that
868 * the bind() functions will be in init sections.
869 * This function must be called in a context that can sleep.
870 */
871 int usb_gadget_register_driver(struct usb_gadget_driver *driver);
872
873 /**
874 * usb_gadget_unregister_driver - unregister a gadget driver
875 * @driver:the driver being unregistered
876 *
877 * Call this in your gadget driver's module cleanup function,
878 * to tell the underlying usb controller that your driver is
879 * going away. If the controller is connected to a USB host,
880 * it will first disconnect(). The driver is also requested
881 * to unbind() and clean up any device state, before this procedure
882 * finally returns. It's expected that the unbind() functions
883 * will in in exit sections, so may not be linked in some kernels.
884 * This function must be called in a context that can sleep.
885 */
886 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
887
888 int usb_add_gadget_udc_release(struct device *parent,
889 struct usb_gadget *gadget, void (*release)(struct device *dev));
890 int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
891 void usb_del_gadget_udc(struct usb_gadget *gadget);
892 /*-------------------------------------------------------------------------*/
893
894 /* utility to simplify dealing with string descriptors */
895
896 /**
897 * struct usb_gadget_strings - a set of USB strings in a given language
898 * @language:identifies the strings' language (0x0409 for en-us)
899 * @strings:array of strings with their ids
900 *
901 * If you're using usb_gadget_get_string(), use this to wrap all the
902 * strings for a given language.
903 */
904 struct usb_gadget_strings {
905 u16 language; /* 0x0409 for en-us */
906 struct usb_string *strings;
907 };
908
909 /* put descriptor for string with that id into buf (buflen >= 256) */
910 int usb_gadget_get_string(struct usb_gadget_strings *table, int id, u8 *buf);
911
912 /*-------------------------------------------------------------------------*/
913
914 /* utility to simplify managing config descriptors */
915
916 /* write vector of descriptors into buffer */
917 int usb_descriptor_fillbuf(void *, unsigned,
918 const struct usb_descriptor_header **);
919
920 /* build config descriptor from single descriptor vector */
921 int usb_gadget_config_buf(const struct usb_config_descriptor *config,
922 void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
923
924 /*-------------------------------------------------------------------------*/
925 /* utility to simplify map/unmap of usb_requests to/from DMA */
926
927 extern int usb_gadget_map_request(struct usb_gadget *gadget,
928 struct usb_request *req, int is_in);
929
930 extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
931 struct usb_request *req, int is_in);
932
933 /*-------------------------------------------------------------------------*/
934
935 /* utility to set gadget state properly */
936
937 extern void usb_gadget_set_state(struct usb_gadget *gadget,
938 enum usb_device_state state);
939
940 /*-------------------------------------------------------------------------*/
941
942 /* utility to tell udc core that the bus reset occurs */
943 extern void usb_gadget_udc_reset(struct usb_gadget *gadget,
944 struct usb_gadget_driver *driver);
945
946 /*-------------------------------------------------------------------------*/
947
948 /* utility to give requests back to the gadget layer */
949
950 extern void usb_gadget_giveback_request(struct usb_ep *ep,
951 struct usb_request *req);
952
953 /*-------------------------------------------------------------------------*/
954
955 /* utility wrapping a simple endpoint selection policy */
956
957 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
958 struct usb_endpoint_descriptor *);
959
960 extern void usb_ep_autoconfig_reset(struct usb_gadget *);
961
962 extern int usb_gadget_handle_interrupts(int index);
963
964 #if CONFIG_IS_ENABLED(DM_USB_GADGET)
965 int usb_gadget_initialize(int index);
966 int usb_gadget_release(int index);
967 int dm_usb_gadget_handle_interrupts(struct udevice *dev);
968 #else
969 #include <usb.h>
usb_gadget_initialize(int index)970 static inline int usb_gadget_initialize(int index)
971 {
972 return board_usb_init(index, USB_INIT_DEVICE);
973 }
974
usb_gadget_release(int index)975 static inline int usb_gadget_release(int index)
976 {
977 return board_usb_cleanup(index, USB_INIT_DEVICE);
978 }
979 #endif
980
981 #endif /* __LINUX_USB_GADGET_H */
982