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_dcd_config_params {
453 	__u8  bU1devExitLat;	/* U1 Device exit Latency */
454 	__le16 bU2DevExitLat;	/* U2 Device exit Latency */
455 };
456 
457 struct usb_gadget;
458 struct usb_gadget_driver;
459 
460 /* the rest of the api to the controller hardware: device operations,
461  * which don't involve endpoints (or i/o).
462  */
463 struct usb_gadget_ops {
464 	int	(*get_frame)(struct usb_gadget *);
465 	int	(*wakeup)(struct usb_gadget *);
466 	int	(*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
467 	int	(*vbus_session) (struct usb_gadget *, int is_active);
468 	int	(*vbus_draw) (struct usb_gadget *, unsigned mA);
469 	int	(*pullup) (struct usb_gadget *, int is_on);
470 	int	(*ioctl)(struct usb_gadget *,
471 				unsigned code, unsigned long param);
472 	void	(*get_config_params)(struct usb_dcd_config_params *);
473 	int	(*udc_start)(struct usb_gadget *,
474 			     struct usb_gadget_driver *);
475 	int	(*udc_stop)(struct usb_gadget *);
476 	struct usb_ep *(*match_ep)(struct usb_gadget *,
477 			struct usb_endpoint_descriptor *,
478 			struct usb_ss_ep_comp_descriptor *);
479 	int   (*ep_conf)(struct usb_gadget *,
480 			struct usb_ep *,
481 			struct usb_endpoint_descriptor *);
482 	void	(*udc_set_speed)(struct usb_gadget *gadget,
483 				 enum usb_device_speed);
484 };
485 
486 /**
487  * struct usb_gadget - represents a usb slave device
488  * @ops: Function pointers used to access hardware-specific operations.
489  * @ep0: Endpoint zero, used when reading or writing responses to
490  *	driver setup() requests
491  * @ep_list: List of other endpoints supported by the device.
492  * @speed: Speed of current connection to USB host.
493  * @max_speed: Maximal speed the UDC can handle.  UDC must support this
494  *      and all slower speeds.
495  * @is_dualspeed: true if the controller supports both high and full speed
496  *	operation.  If it does, the gadget driver must also support both.
497  * @is_otg: true if the USB device port uses a Mini-AB jack, so that the
498  *	gadget driver must provide a USB OTG descriptor.
499  * @is_a_peripheral: false unless is_otg, the "A" end of a USB cable
500  *	is in the Mini-AB jack, and HNP has been used to switch roles
501  *	so that the "A" device currently acts as A-Peripheral, not A-Host.
502  * @a_hnp_support: OTG device feature flag, indicating that the A-Host
503  *	supports HNP at this port.
504  * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
505  *	only supports HNP on a different root port.
506  * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
507  *	enabled HNP support.
508  * @name: Identifies the controller hardware type.  Used in diagnostics
509  *	and sometimes configuration.
510  * @dev: Driver model state for this abstract device.
511  * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
512  *	MaxPacketSize.
513  *
514  * Gadgets have a mostly-portable "gadget driver" implementing device
515  * functions, handling all usb configurations and interfaces.  Gadget
516  * drivers talk to hardware-specific code indirectly, through ops vectors.
517  * That insulates the gadget driver from hardware details, and packages
518  * the hardware endpoints through generic i/o queues.  The "usb_gadget"
519  * and "usb_ep" interfaces provide that insulation from the hardware.
520  *
521  * Except for the driver data, all fields in this structure are
522  * read-only to the gadget driver.  That driver data is part of the
523  * "driver model" infrastructure in 2.6 (and later) kernels, and for
524  * earlier systems is grouped in a similar structure that's not known
525  * to the rest of the kernel.
526  *
527  * Values of the three OTG device feature flags are updated before the
528  * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
529  * driver suspend() calls.  They are valid only when is_otg, and when the
530  * device is acting as a B-Peripheral (so is_a_peripheral is false).
531  */
532 struct usb_gadget {
533 	/* readonly to gadget driver */
534 	const struct usb_gadget_ops	*ops;
535 	struct usb_ep			*ep0;
536 	struct list_head		ep_list;	/* of usb_ep */
537 	enum usb_device_speed		speed;
538 	enum usb_device_speed		max_speed;
539 	enum usb_device_state		state;
540 	unsigned			is_dualspeed:1;
541 	unsigned			is_otg:1;
542 	unsigned			is_a_peripheral:1;
543 	unsigned			b_hnp_enable:1;
544 	unsigned			a_hnp_support:1;
545 	unsigned			a_alt_hnp_support:1;
546 	const char			*name;
547 	struct device			dev;
548 	unsigned			quirk_ep_out_aligned_size:1;
549 };
550 
set_gadget_data(struct usb_gadget * gadget,void * data)551 static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
552 {
553 	gadget->dev.driver_data = data;
554 }
555 
get_gadget_data(struct usb_gadget * gadget)556 static inline void *get_gadget_data(struct usb_gadget *gadget)
557 {
558 	return gadget->dev.driver_data;
559 }
560 
dev_to_usb_gadget(struct device * dev)561 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
562 {
563 	return container_of(dev, struct usb_gadget, dev);
564 }
565 
566 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
567 #define gadget_for_each_ep(tmp, gadget) \
568 	list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
569 
570 
571 /**
572  * gadget_is_dualspeed - return true iff the hardware handles high speed
573  * @g: controller that might support both high and full speeds
574  */
gadget_is_dualspeed(struct usb_gadget * g)575 static inline int gadget_is_dualspeed(struct usb_gadget *g)
576 {
577 #ifdef CONFIG_USB_GADGET_DUALSPEED
578 	/* runtime test would check "g->is_dualspeed" ... that might be
579 	 * useful to work around hardware bugs, but is mostly pointless
580 	 */
581 	return 1;
582 #else
583 	return 0;
584 #endif
585 }
586 
587 /**
588  * gadget_is_otg - return true iff the hardware is OTG-ready
589  * @g: controller that might have a Mini-AB connector
590  *
591  * This is a runtime test, since kernels with a USB-OTG stack sometimes
592  * run on boards which only have a Mini-B (or Mini-A) connector.
593  */
gadget_is_otg(struct usb_gadget * g)594 static inline int gadget_is_otg(struct usb_gadget *g)
595 {
596 #ifdef CONFIG_USB_OTG
597 	return g->is_otg;
598 #else
599 	return 0;
600 #endif
601 }
602 
603 /**
604  * gadget_is_superspeed() - return true if the hardware handles superspeed
605  * @g: controller that might support superspeed
606  */
gadget_is_superspeed(struct usb_gadget * g)607 static inline int gadget_is_superspeed(struct usb_gadget *g)
608 {
609 	return g->max_speed >= USB_SPEED_SUPER;
610 }
611 
612 /**
613  * usb_gadget_frame_number - returns the current frame number
614  * @gadget: controller that reports the frame number
615  *
616  * Returns the usb frame number, normally eleven bits from a SOF packet,
617  * or negative errno if this device doesn't support this capability.
618  */
usb_gadget_frame_number(struct usb_gadget * gadget)619 static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
620 {
621 	return gadget->ops->get_frame(gadget);
622 }
623 
624 /**
625  * usb_gadget_wakeup - tries to wake up the host connected to this gadget
626  * @gadget: controller used to wake up the host
627  *
628  * Returns zero on success, else negative error code if the hardware
629  * doesn't support such attempts, or its support has not been enabled
630  * by the usb host.  Drivers must return device descriptors that report
631  * their ability to support this, or hosts won't enable it.
632  *
633  * This may also try to use SRP to wake the host and start enumeration,
634  * even if OTG isn't otherwise in use.  OTG devices may also start
635  * remote wakeup even when hosts don't explicitly enable it.
636  */
usb_gadget_wakeup(struct usb_gadget * gadget)637 static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
638 {
639 	if (!gadget->ops->wakeup)
640 		return -EOPNOTSUPP;
641 	return gadget->ops->wakeup(gadget);
642 }
643 
644 /**
645  * usb_gadget_set_selfpowered - sets the device selfpowered feature.
646  * @gadget:the device being declared as self-powered
647  *
648  * this affects the device status reported by the hardware driver
649  * to reflect that it now has a local power supply.
650  *
651  * returns zero on success, else negative errno.
652  */
usb_gadget_set_selfpowered(struct usb_gadget * gadget)653 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
654 {
655 	if (!gadget->ops->set_selfpowered)
656 		return -EOPNOTSUPP;
657 	return gadget->ops->set_selfpowered(gadget, 1);
658 }
659 
660 /**
661  * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
662  * @gadget:the device being declared as bus-powered
663  *
664  * this affects the device status reported by the hardware driver.
665  * some hardware may not support bus-powered operation, in which
666  * case this feature's value can never change.
667  *
668  * returns zero on success, else negative errno.
669  */
usb_gadget_clear_selfpowered(struct usb_gadget * gadget)670 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
671 {
672 	if (!gadget->ops->set_selfpowered)
673 		return -EOPNOTSUPP;
674 	return gadget->ops->set_selfpowered(gadget, 0);
675 }
676 
677 /**
678  * usb_gadget_vbus_connect - Notify controller that VBUS is powered
679  * @gadget:The device which now has VBUS power.
680  *
681  * This call is used by a driver for an external transceiver (or GPIO)
682  * that detects a VBUS power session starting.  Common responses include
683  * resuming the controller, activating the D+ (or D-) pullup to let the
684  * host detect that a USB device is attached, and starting to draw power
685  * (8mA or possibly more, especially after SET_CONFIGURATION).
686  *
687  * Returns zero on success, else negative errno.
688  */
usb_gadget_vbus_connect(struct usb_gadget * gadget)689 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
690 {
691 	if (!gadget->ops->vbus_session)
692 		return -EOPNOTSUPP;
693 	return gadget->ops->vbus_session(gadget, 1);
694 }
695 
696 /**
697  * usb_gadget_vbus_draw - constrain controller's VBUS power usage
698  * @gadget:The device whose VBUS usage is being described
699  * @mA:How much current to draw, in milliAmperes.  This should be twice
700  *	the value listed in the configuration descriptor bMaxPower field.
701  *
702  * This call is used by gadget drivers during SET_CONFIGURATION calls,
703  * reporting how much power the device may consume.  For example, this
704  * could affect how quickly batteries are recharged.
705  *
706  * Returns zero on success, else negative errno.
707  */
usb_gadget_vbus_draw(struct usb_gadget * gadget,unsigned mA)708 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
709 {
710 	if (!gadget->ops->vbus_draw)
711 		return -EOPNOTSUPP;
712 	return gadget->ops->vbus_draw(gadget, mA);
713 }
714 
715 /**
716  * usb_gadget_vbus_disconnect - notify controller about VBUS session end
717  * @gadget:the device whose VBUS supply is being described
718  *
719  * This call is used by a driver for an external transceiver (or GPIO)
720  * that detects a VBUS power session ending.  Common responses include
721  * reversing everything done in usb_gadget_vbus_connect().
722  *
723  * Returns zero on success, else negative errno.
724  */
usb_gadget_vbus_disconnect(struct usb_gadget * gadget)725 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
726 {
727 	if (!gadget->ops->vbus_session)
728 		return -EOPNOTSUPP;
729 	return gadget->ops->vbus_session(gadget, 0);
730 }
731 
732 /**
733  * usb_gadget_connect - software-controlled connect to USB host
734  * @gadget:the peripheral being connected
735  *
736  * Enables the D+ (or potentially D-) pullup.  The host will start
737  * enumerating this gadget when the pullup is active and a VBUS session
738  * is active (the link is powered).  This pullup is always enabled unless
739  * usb_gadget_disconnect() has been used to disable it.
740  *
741  * Returns zero on success, else negative errno.
742  */
usb_gadget_connect(struct usb_gadget * gadget)743 static inline int usb_gadget_connect(struct usb_gadget *gadget)
744 {
745 	if (!gadget->ops->pullup)
746 		return -EOPNOTSUPP;
747 	return gadget->ops->pullup(gadget, 1);
748 }
749 
750 /**
751  * usb_gadget_disconnect - software-controlled disconnect from USB host
752  * @gadget:the peripheral being disconnected
753  *
754  * Disables the D+ (or potentially D-) pullup, which the host may see
755  * as a disconnect (when a VBUS session is active).  Not all systems
756  * support software pullup controls.
757  *
758  * This routine may be used during the gadget driver bind() call to prevent
759  * the peripheral from ever being visible to the USB host, unless later
760  * usb_gadget_connect() is called.  For example, user mode components may
761  * need to be activated before the system can talk to hosts.
762  *
763  * Returns zero on success, else negative errno.
764  */
usb_gadget_disconnect(struct usb_gadget * gadget)765 static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
766 {
767 	if (!gadget->ops->pullup)
768 		return -EOPNOTSUPP;
769 	return gadget->ops->pullup(gadget, 0);
770 }
771 
772 
773 /*-------------------------------------------------------------------------*/
774 
775 /**
776  * struct usb_gadget_driver - driver for usb 'slave' devices
777  * @function: String describing the gadget's function
778  * @speed: Highest speed the driver handles.
779  * @bind: Invoked when the driver is bound to a gadget, usually
780  *	after registering the driver.
781  *	At that point, ep0 is fully initialized, and ep_list holds
782  *	the currently-available endpoints.
783  *	Called in a context that permits sleeping.
784  * @setup: Invoked for ep0 control requests that aren't handled by
785  *	the hardware level driver. Most calls must be handled by
786  *	the gadget driver, including descriptor and configuration
787  *	management.  The 16 bit members of the setup data are in
788  *	USB byte order. Called in_interrupt; this may not sleep.  Driver
789  *	queues a response to ep0, or returns negative to stall.
790  * @disconnect: Invoked after all transfers have been stopped,
791  *	when the host is disconnected.  May be called in_interrupt; this
792  *	may not sleep.  Some devices can't detect disconnect, so this might
793  *	not be called except as part of controller shutdown.
794  * @unbind: Invoked when the driver is unbound from a gadget,
795  *	usually from rmmod (after a disconnect is reported).
796  *	Called in a context that permits sleeping.
797  * @suspend: Invoked on USB suspend.  May be called in_interrupt.
798  * @resume: Invoked on USB resume.  May be called in_interrupt.
799  * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers
800  *	and should be called in_interrupt.
801  *
802  * Devices are disabled till a gadget driver successfully bind()s, which
803  * means the driver will handle setup() requests needed to enumerate (and
804  * meet "chapter 9" requirements) then do some useful work.
805  *
806  * If gadget->is_otg is true, the gadget driver must provide an OTG
807  * descriptor during enumeration, or else fail the bind() call.  In such
808  * cases, no USB traffic may flow until both bind() returns without
809  * having called usb_gadget_disconnect(), and the USB host stack has
810  * initialized.
811  *
812  * Drivers use hardware-specific knowledge to configure the usb hardware.
813  * endpoint addressing is only one of several hardware characteristics that
814  * are in descriptors the ep0 implementation returns from setup() calls.
815  *
816  * Except for ep0 implementation, most driver code shouldn't need change to
817  * run on top of different usb controllers.  It'll use endpoints set up by
818  * that ep0 implementation.
819  *
820  * The usb controller driver handles a few standard usb requests.  Those
821  * include set_address, and feature flags for devices, interfaces, and
822  * endpoints (the get_status, set_feature, and clear_feature requests).
823  *
824  * Accordingly, the driver's setup() callback must always implement all
825  * get_descriptor requests, returning at least a device descriptor and
826  * a configuration descriptor.  Drivers must make sure the endpoint
827  * descriptors match any hardware constraints. Some hardware also constrains
828  * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
829  *
830  * The driver's setup() callback must also implement set_configuration,
831  * and should also implement set_interface, get_configuration, and
832  * get_interface.  Setting a configuration (or interface) is where
833  * endpoints should be activated or (config 0) shut down.
834  *
835  * (Note that only the default control endpoint is supported.  Neither
836  * hosts nor devices generally support control traffic except to ep0.)
837  *
838  * Most devices will ignore USB suspend/resume operations, and so will
839  * not provide those callbacks.  However, some may need to change modes
840  * when the host is not longer directing those activities.  For example,
841  * local controls (buttons, dials, etc) may need to be re-enabled since
842  * the (remote) host can't do that any longer; or an error state might
843  * be cleared, to make the device behave identically whether or not
844  * power is maintained.
845  */
846 struct usb_gadget_driver {
847 	char			*function;
848 	enum usb_device_speed	speed;
849 	int			(*bind)(struct usb_gadget *);
850 	void			(*unbind)(struct usb_gadget *);
851 	int			(*setup)(struct usb_gadget *,
852 					const struct usb_ctrlrequest *);
853 	void			(*disconnect)(struct usb_gadget *);
854 	void			(*suspend)(struct usb_gadget *);
855 	void			(*resume)(struct usb_gadget *);
856 	void			(*reset)(struct usb_gadget *);
857 };
858 
859 
860 /*-------------------------------------------------------------------------*/
861 
862 /* driver modules register and unregister, as usual.
863  * these calls must be made in a context that can sleep.
864  *
865  * these will usually be implemented directly by the hardware-dependent
866  * usb bus interface driver, which will only support a single driver.
867  */
868 
869 /**
870  * usb_gadget_register_driver - register a gadget driver
871  * @driver:the driver being registered
872  *
873  * Call this in your gadget driver's module initialization function,
874  * to tell the underlying usb controller driver about your driver.
875  * The driver's bind() function will be called to bind it to a
876  * gadget before this registration call returns.  It's expected that
877  * the bind() functions will be in init sections.
878  * This function must be called in a context that can sleep.
879  */
880 int usb_gadget_register_driver(struct usb_gadget_driver *driver);
881 
882 /**
883  * usb_gadget_unregister_driver - unregister a gadget driver
884  * @driver:the driver being unregistered
885  *
886  * Call this in your gadget driver's module cleanup function,
887  * to tell the underlying usb controller that your driver is
888  * going away.  If the controller is connected to a USB host,
889  * it will first disconnect().  The driver is also requested
890  * to unbind() and clean up any device state, before this procedure
891  * finally returns.  It's expected that the unbind() functions
892  * will in in exit sections, so may not be linked in some kernels.
893  * This function must be called in a context that can sleep.
894  */
895 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
896 
897 int usb_add_gadget_udc_release(struct device *parent,
898 		struct usb_gadget *gadget, void (*release)(struct device *dev));
899 int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
900 void usb_del_gadget_udc(struct usb_gadget *gadget);
901 /*-------------------------------------------------------------------------*/
902 
903 /* utility to simplify dealing with string descriptors */
904 
905 /**
906  * struct usb_gadget_strings - a set of USB strings in a given language
907  * @language:identifies the strings' language (0x0409 for en-us)
908  * @strings:array of strings with their ids
909  *
910  * If you're using usb_gadget_get_string(), use this to wrap all the
911  * strings for a given language.
912  */
913 struct usb_gadget_strings {
914 	u16			language;	/* 0x0409 for en-us */
915 	struct usb_string	*strings;
916 };
917 
918 /* put descriptor for string with that id into buf (buflen >= 256) */
919 int usb_gadget_get_string(struct usb_gadget_strings *table, int id, u8 *buf);
920 
921 /*-------------------------------------------------------------------------*/
922 
923 /* utility to simplify managing config descriptors */
924 
925 /* write vector of descriptors into buffer */
926 int usb_descriptor_fillbuf(void *, unsigned,
927 		const struct usb_descriptor_header **);
928 
929 /* build config descriptor from single descriptor vector */
930 int usb_gadget_config_buf(const struct usb_config_descriptor *config,
931 	void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
932 
933 /*-------------------------------------------------------------------------*/
934 /* utility to simplify map/unmap of usb_requests to/from DMA */
935 
936 extern int usb_gadget_map_request(struct usb_gadget *gadget,
937 				  struct usb_request *req, int is_in);
938 
939 extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
940 				     struct usb_request *req, int is_in);
941 
942 /*-------------------------------------------------------------------------*/
943 
944 /* utility to set gadget state properly */
945 
946 extern void usb_gadget_set_state(struct usb_gadget *gadget,
947 				 enum usb_device_state state);
948 
949 /*-------------------------------------------------------------------------*/
950 
951 /* utility to tell udc core that the bus reset occurs */
952 extern void usb_gadget_udc_reset(struct usb_gadget *gadget,
953 				 struct usb_gadget_driver *driver);
954 
955 /*-------------------------------------------------------------------------*/
956 
957 /* utility to give requests back to the gadget layer */
958 
959 extern void usb_gadget_giveback_request(struct usb_ep *ep,
960 					struct usb_request *req);
961 
962 /*-------------------------------------------------------------------------*/
963 
964 /* utility wrapping a simple endpoint selection policy */
965 
966 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
967 			struct usb_endpoint_descriptor *);
968 
969 extern void usb_ep_autoconfig_reset(struct usb_gadget *);
970 
971 extern int usb_gadget_handle_interrupts(int index);
972 
973 #if CONFIG_IS_ENABLED(DM_USB_GADGET)
974 int usb_gadget_initialize(int index);
975 int usb_gadget_release(int index);
976 int dm_usb_gadget_handle_interrupts(struct udevice *dev);
977 #else
978 #include <usb.h>
usb_gadget_initialize(int index)979 static inline int usb_gadget_initialize(int index)
980 {
981 	return board_usb_init(index, USB_INIT_DEVICE);
982 }
983 
usb_gadget_release(int index)984 static inline int usb_gadget_release(int index)
985 {
986 	return board_usb_cleanup(index, USB_INIT_DEVICE);
987 }
988 #endif
989 
990 #endif	/* __LINUX_USB_GADGET_H */
991