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Remy Bohmer23cd1382009-07-29 18:18:43 +02001/*
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 *
Bin Menga1875592016-02-05 19:30:11 -080014 * Ported to U-Boot by: Thomas Smits <ts.smits@gmail.com> and
Remy Bohmer23cd1382009-07-29 18:18:43 +020015 * Remy Bohmer <linux@bohmer.net>
16 */
17
18#ifndef __LINUX_USB_GADGET_H
19#define __LINUX_USB_GADGET_H
20
Lukasz Majewski69d6cbe2013-09-17 15:58:22 +020021#include <errno.h>
Heiko Schocher0c06db52014-06-24 10:10:03 +020022#include <linux/compat.h>
Remy Bohmer23cd1382009-07-29 18:18:43 +020023#include <linux/list.h>
24
25struct usb_ep;
26
27/**
28 * struct usb_request - describes one i/o request
29 * @buf: Buffer used for data. Always provide this; some controllers
30 * only use PIO, or don't use DMA for some endpoints.
31 * @dma: DMA address corresponding to 'buf'. If you don't set this
32 * field, and the usb controller needs one, it is responsible
33 * for mapping and unmapping the buffer.
Kishon Vijay Abraham I747a0a52015-02-23 18:39:58 +053034 * @stream_id: The stream id, when USB3.0 bulk streams are being used
Remy Bohmer23cd1382009-07-29 18:18:43 +020035 * @length: Length of that data
36 * @no_interrupt: If true, hints that no completion irq is needed.
37 * Helpful sometimes with deep request queues that are handled
38 * directly by DMA controllers.
39 * @zero: If true, when writing data, makes the last packet be "short"
40 * by adding a zero length packet as needed;
41 * @short_not_ok: When reading data, makes short packets be
42 * treated as errors (queue stops advancing till cleanup).
43 * @complete: Function called when request completes, so this request and
44 * its buffer may be re-used.
45 * Reads terminate with a short packet, or when the buffer fills,
46 * whichever comes first. When writes terminate, some data bytes
47 * will usually still be in flight (often in a hardware fifo).
48 * Errors (for reads or writes) stop the queue from advancing
49 * until the completion function returns, so that any transfers
50 * invalidated by the error may first be dequeued.
51 * @context: For use by the completion callback
52 * @list: For use by the gadget driver.
53 * @status: Reports completion code, zero or a negative errno.
54 * Normally, faults block the transfer queue from advancing until
55 * the completion callback returns.
56 * Code "-ESHUTDOWN" indicates completion caused by device disconnect,
57 * or when the driver disabled the endpoint.
58 * @actual: Reports bytes transferred to/from the buffer. For reads (OUT
59 * transfers) this may be less than the requested length. If the
60 * short_not_ok flag is set, short reads are treated as errors
61 * even when status otherwise indicates successful completion.
62 * Note that for writes (IN transfers) some data bytes may still
63 * reside in a device-side FIFO when the request is reported as
64 * complete.
65 *
66 * These are allocated/freed through the endpoint they're used with. The
67 * hardware's driver can add extra per-request data to the memory it returns,
68 * which often avoids separate memory allocations (potential failures),
69 * later when the request is queued.
70 *
71 * Request flags affect request handling, such as whether a zero length
72 * packet is written (the "zero" flag), whether a short read should be
73 * treated as an error (blocking request queue advance, the "short_not_ok"
74 * flag), or hinting that an interrupt is not required (the "no_interrupt"
75 * flag, for use with deep request queues).
76 *
77 * Bulk endpoints can use any size buffers, and can also be used for interrupt
78 * transfers. interrupt-only endpoints can be much less functional.
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +040079 *
80 * NOTE: this is analagous to 'struct urb' on the host side, except that
81 * it's thinner and promotes more pre-allocation.
Remy Bohmer23cd1382009-07-29 18:18:43 +020082 */
Remy Bohmer23cd1382009-07-29 18:18:43 +020083
84struct usb_request {
85 void *buf;
86 unsigned length;
87 dma_addr_t dma;
88
Kishon Vijay Abraham I747a0a52015-02-23 18:39:58 +053089 unsigned stream_id:16;
Remy Bohmer23cd1382009-07-29 18:18:43 +020090 unsigned no_interrupt:1;
91 unsigned zero:1;
92 unsigned short_not_ok:1;
93
94 void (*complete)(struct usb_ep *ep,
95 struct usb_request *req);
96 void *context;
97 struct list_head list;
98
99 int status;
100 unsigned actual;
101};
102
103/*-------------------------------------------------------------------------*/
104
105/* endpoint-specific parts of the api to the usb controller hardware.
106 * unlike the urb model, (de)multiplexing layers are not required.
107 * (so this api could slash overhead if used on the host side...)
108 *
109 * note that device side usb controllers commonly differ in how many
110 * endpoints they support, as well as their capabilities.
111 */
112struct usb_ep_ops {
113 int (*enable) (struct usb_ep *ep,
114 const struct usb_endpoint_descriptor *desc);
115 int (*disable) (struct usb_ep *ep);
116
117 struct usb_request *(*alloc_request) (struct usb_ep *ep,
118 gfp_t gfp_flags);
119 void (*free_request) (struct usb_ep *ep, struct usb_request *req);
120
121 int (*queue) (struct usb_ep *ep, struct usb_request *req,
122 gfp_t gfp_flags);
123 int (*dequeue) (struct usb_ep *ep, struct usb_request *req);
124
125 int (*set_halt) (struct usb_ep *ep, int value);
Kishon Vijay Abraham I747a0a52015-02-23 18:39:58 +0530126 int (*set_wedge)(struct usb_ep *ep);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200127 int (*fifo_status) (struct usb_ep *ep);
128 void (*fifo_flush) (struct usb_ep *ep);
129};
130
131/**
132 * struct usb_ep - device side representation of USB endpoint
133 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk"
134 * @ops: Function pointers used to access hardware-specific operations.
135 * @ep_list:the gadget's ep_list holds all of its endpoints
136 * @maxpacket:The maximum packet size used on this endpoint. The initial
137 * value can sometimes be reduced (hardware allowing), according to
138 * the endpoint descriptor used to configure the endpoint.
Kishon Vijay Abraham I747a0a52015-02-23 18:39:58 +0530139 * @maxpacket_limit:The maximum packet size value which can be handled by this
140 * endpoint. It's set once by UDC driver when endpoint is initialized, and
141 * should not be changed. Should not be confused with maxpacket.
142 * @max_streams: The maximum number of streams supported
143 * by this EP (0 - 16, actual number is 2^n)
144 * @maxburst: the maximum number of bursts supported by this EP (for usb3)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200145 * @driver_data:for use by the gadget driver. all other fields are
146 * read-only to gadget drivers.
Kishon Vijay Abraham I747a0a52015-02-23 18:39:58 +0530147 * @desc: endpoint descriptor. This pointer is set before the endpoint is
148 * enabled and remains valid until the endpoint is disabled.
149 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion
150 * descriptor that is used to configure the endpoint
Remy Bohmer23cd1382009-07-29 18:18:43 +0200151 *
152 * the bus controller driver lists all the general purpose endpoints in
153 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list,
154 * and is accessed only in response to a driver setup() callback.
155 */
156struct usb_ep {
157 void *driver_data;
158 const char *name;
159 const struct usb_ep_ops *ops;
160 struct list_head ep_list;
161 unsigned maxpacket:16;
Kishon Vijay Abraham I747a0a52015-02-23 18:39:58 +0530162 unsigned maxpacket_limit:16;
163 unsigned max_streams:16;
164 unsigned maxburst:5;
165 const struct usb_endpoint_descriptor *desc;
166 const struct usb_ss_ep_comp_descriptor *comp_desc;
Remy Bohmer23cd1382009-07-29 18:18:43 +0200167};
168
169/*-------------------------------------------------------------------------*/
170
171/**
Kishon Vijay Abraham I747a0a52015-02-23 18:39:58 +0530172 * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
173 * @ep:the endpoint being configured
174 * @maxpacket_limit:value of maximum packet size limit
175 *
176 * This function shoud be used only in UDC drivers to initialize endpoint
177 * (usually in probe function).
178 */
179static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
180 unsigned maxpacket_limit)
181{
182 ep->maxpacket_limit = maxpacket_limit;
183 ep->maxpacket = maxpacket_limit;
184}
185
186/**
Remy Bohmer23cd1382009-07-29 18:18:43 +0200187 * usb_ep_enable - configure endpoint, making it usable
188 * @ep:the endpoint being configured. may not be the endpoint named "ep0".
189 * drivers discover endpoints through the ep_list of a usb_gadget.
190 * @desc:descriptor for desired behavior. caller guarantees this pointer
191 * remains valid until the endpoint is disabled; the data byte order
192 * is little-endian (usb-standard).
193 *
194 * when configurations are set, or when interface settings change, the driver
195 * will enable or disable the relevant endpoints. while it is enabled, an
196 * endpoint may be used for i/o until the driver receives a disconnect() from
197 * the host or until the endpoint is disabled.
198 *
199 * the ep0 implementation (which calls this routine) must ensure that the
200 * hardware capabilities of each endpoint match the descriptor provided
201 * for it. for example, an endpoint named "ep2in-bulk" would be usable
202 * for interrupt transfers as well as bulk, but it likely couldn't be used
203 * for iso transfers or for endpoint 14. some endpoints are fully
204 * configurable, with more generic names like "ep-a". (remember that for
205 * USB, "in" means "towards the USB master".)
206 *
207 * returns zero, or a negative error code.
208 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400209static inline int usb_ep_enable(struct usb_ep *ep,
210 const struct usb_endpoint_descriptor *desc)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200211{
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400212 return ep->ops->enable(ep, desc);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200213}
214
215/**
216 * usb_ep_disable - endpoint is no longer usable
217 * @ep:the endpoint being unconfigured. may not be the endpoint named "ep0".
218 *
219 * no other task may be using this endpoint when this is called.
220 * any pending and uncompleted requests will complete with status
221 * indicating disconnect (-ESHUTDOWN) before this call returns.
222 * gadget drivers must call usb_ep_enable() again before queueing
223 * requests to the endpoint.
224 *
225 * returns zero, or a negative error code.
226 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400227static inline int usb_ep_disable(struct usb_ep *ep)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200228{
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400229 return ep->ops->disable(ep);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200230}
231
232/**
233 * usb_ep_alloc_request - allocate a request object to use with this endpoint
234 * @ep:the endpoint to be used with with the request
235 * @gfp_flags:GFP_* flags to use
236 *
237 * Request objects must be allocated with this call, since they normally
238 * need controller-specific setup and may even need endpoint-specific
239 * resources such as allocation of DMA descriptors.
240 * Requests may be submitted with usb_ep_queue(), and receive a single
241 * completion callback. Free requests with usb_ep_free_request(), when
242 * they are no longer needed.
243 *
244 * Returns the request, or null if one could not be allocated.
245 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400246static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
247 gfp_t gfp_flags)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200248{
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400249 return ep->ops->alloc_request(ep, gfp_flags);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200250}
251
252/**
253 * usb_ep_free_request - frees a request object
254 * @ep:the endpoint associated with the request
255 * @req:the request being freed
256 *
257 * Reverses the effect of usb_ep_alloc_request().
258 * Caller guarantees the request is not queued, and that it will
259 * no longer be requeued (or otherwise used).
260 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400261static inline void usb_ep_free_request(struct usb_ep *ep,
262 struct usb_request *req)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200263{
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400264 ep->ops->free_request(ep, req);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200265}
266
267/**
268 * usb_ep_queue - queues (submits) an I/O request to an endpoint.
269 * @ep:the endpoint associated with the request
270 * @req:the request being submitted
271 * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
272 * pre-allocate all necessary memory with the request.
273 *
274 * This tells the device controller to perform the specified request through
275 * that endpoint (reading or writing a buffer). When the request completes,
276 * including being canceled by usb_ep_dequeue(), the request's completion
277 * routine is called to return the request to the driver. Any endpoint
278 * (except control endpoints like ep0) may have more than one transfer
279 * request queued; they complete in FIFO order. Once a gadget driver
280 * submits a request, that request may not be examined or modified until it
281 * is given back to that driver through the completion callback.
282 *
283 * Each request is turned into one or more packets. The controller driver
284 * never merges adjacent requests into the same packet. OUT transfers
285 * will sometimes use data that's already buffered in the hardware.
286 * Drivers can rely on the fact that the first byte of the request's buffer
287 * always corresponds to the first byte of some USB packet, for both
288 * IN and OUT transfers.
289 *
290 * Bulk endpoints can queue any amount of data; the transfer is packetized
291 * automatically. The last packet will be short if the request doesn't fill it
292 * out completely. Zero length packets (ZLPs) should be avoided in portable
293 * protocols since not all usb hardware can successfully handle zero length
294 * packets. (ZLPs may be explicitly written, and may be implicitly written if
295 * the request 'zero' flag is set.) Bulk endpoints may also be used
296 * for interrupt transfers; but the reverse is not true, and some endpoints
297 * won't support every interrupt transfer. (Such as 768 byte packets.)
298 *
299 * Interrupt-only endpoints are less functional than bulk endpoints, for
300 * example by not supporting queueing or not handling buffers that are
301 * larger than the endpoint's maxpacket size. They may also treat data
302 * toggle differently.
303 *
304 * Control endpoints ... after getting a setup() callback, the driver queues
305 * one response (even if it would be zero length). That enables the
306 * status ack, after transfering data as specified in the response. Setup
307 * functions may return negative error codes to generate protocol stalls.
308 * (Note that some USB device controllers disallow protocol stall responses
309 * in some cases.) When control responses are deferred (the response is
310 * written after the setup callback returns), then usb_ep_set_halt() may be
311 * used on ep0 to trigger protocol stalls.
312 *
313 * For periodic endpoints, like interrupt or isochronous ones, the usb host
314 * arranges to poll once per interval, and the gadget driver usually will
315 * have queued some data to transfer at that time.
316 *
317 * Returns zero, or a negative error code. Endpoints that are not enabled
318 * report errors; errors will also be
319 * reported when the usb peripheral is disconnected.
320 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400321static inline int usb_ep_queue(struct usb_ep *ep,
322 struct usb_request *req, gfp_t gfp_flags)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200323{
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400324 return ep->ops->queue(ep, req, gfp_flags);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200325}
326
327/**
328 * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
329 * @ep:the endpoint associated with the request
330 * @req:the request being canceled
331 *
332 * if the request is still active on the endpoint, it is dequeued and its
333 * completion routine is called (with status -ECONNRESET); else a negative
334 * error code is returned.
335 *
336 * note that some hardware can't clear out write fifos (to unlink the request
337 * at the head of the queue) except as part of disconnecting from usb. such
338 * restrictions prevent drivers from supporting configuration changes,
339 * even to configuration zero (a "chapter 9" requirement).
340 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400341static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200342{
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400343 return ep->ops->dequeue(ep, req);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200344}
345
346/**
347 * usb_ep_set_halt - sets the endpoint halt feature.
348 * @ep: the non-isochronous endpoint being stalled
349 *
350 * Use this to stall an endpoint, perhaps as an error report.
351 * Except for control endpoints,
352 * the endpoint stays halted (will not stream any data) until the host
353 * clears this feature; drivers may need to empty the endpoint's request
354 * queue first, to make sure no inappropriate transfers happen.
355 *
356 * Note that while an endpoint CLEAR_FEATURE will be invisible to the
357 * gadget driver, a SET_INTERFACE will not be. To reset endpoints for the
358 * current altsetting, see usb_ep_clear_halt(). When switching altsettings,
359 * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
360 *
361 * Returns zero, or a negative error code. On success, this call sets
362 * underlying hardware state that blocks data transfers.
363 * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
364 * transfer requests are still queued, or if the controller hardware
365 * (usually a FIFO) still holds bytes that the host hasn't collected.
366 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400367static inline int usb_ep_set_halt(struct usb_ep *ep)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200368{
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400369 return ep->ops->set_halt(ep, 1);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200370}
371
372/**
373 * usb_ep_clear_halt - clears endpoint halt, and resets toggle
374 * @ep:the bulk or interrupt endpoint being reset
375 *
376 * Use this when responding to the standard usb "set interface" request,
377 * for endpoints that aren't reconfigured, after clearing any other state
378 * in the endpoint's i/o queue.
379 *
380 * Returns zero, or a negative error code. On success, this call clears
381 * the underlying hardware state reflecting endpoint halt and data toggle.
382 * Note that some hardware can't support this request (like pxa2xx_udc),
383 * and accordingly can't correctly implement interface altsettings.
384 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400385static inline int usb_ep_clear_halt(struct usb_ep *ep)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200386{
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400387 return ep->ops->set_halt(ep, 0);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200388}
389
390/**
391 * usb_ep_fifo_status - returns number of bytes in fifo, or error
392 * @ep: the endpoint whose fifo status is being checked.
393 *
394 * FIFO endpoints may have "unclaimed data" in them in certain cases,
395 * such as after aborted transfers. Hosts may not have collected all
396 * the IN data written by the gadget driver (and reported by a request
397 * completion). The gadget driver may not have collected all the data
398 * written OUT to it by the host. Drivers that need precise handling for
399 * fault reporting or recovery may need to use this call.
400 *
401 * This returns the number of such bytes in the fifo, or a negative
402 * errno if the endpoint doesn't use a FIFO or doesn't support such
403 * precise handling.
404 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400405static inline int usb_ep_fifo_status(struct usb_ep *ep)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200406{
407 if (ep->ops->fifo_status)
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400408 return ep->ops->fifo_status(ep);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200409 else
410 return -EOPNOTSUPP;
411}
412
413/**
414 * usb_ep_fifo_flush - flushes contents of a fifo
415 * @ep: the endpoint whose fifo is being flushed.
416 *
417 * This call may be used to flush the "unclaimed data" that may exist in
418 * an endpoint fifo after abnormal transaction terminations. The call
419 * must never be used except when endpoint is not being used for any
420 * protocol translation.
421 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400422static inline void usb_ep_fifo_flush(struct usb_ep *ep)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200423{
424 if (ep->ops->fifo_flush)
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400425 ep->ops->fifo_flush(ep);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200426}
427
428
429/*-------------------------------------------------------------------------*/
430
431struct usb_gadget;
Kishon Vijay Abraham I45d93372015-02-23 18:39:47 +0530432struct usb_gadget_driver;
Remy Bohmer23cd1382009-07-29 18:18:43 +0200433
434/* the rest of the api to the controller hardware: device operations,
435 * which don't involve endpoints (or i/o).
436 */
437struct usb_gadget_ops {
438 int (*get_frame)(struct usb_gadget *);
439 int (*wakeup)(struct usb_gadget *);
440 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
441 int (*vbus_session) (struct usb_gadget *, int is_active);
442 int (*vbus_draw) (struct usb_gadget *, unsigned mA);
443 int (*pullup) (struct usb_gadget *, int is_on);
444 int (*ioctl)(struct usb_gadget *,
445 unsigned code, unsigned long param);
Kishon Vijay Abraham I45d93372015-02-23 18:39:47 +0530446 int (*udc_start)(struct usb_gadget *,
447 struct usb_gadget_driver *);
448 int (*udc_stop)(struct usb_gadget *);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200449};
450
Remy Bohmer23cd1382009-07-29 18:18:43 +0200451/**
452 * struct usb_gadget - represents a usb slave device
453 * @ops: Function pointers used to access hardware-specific operations.
454 * @ep0: Endpoint zero, used when reading or writing responses to
455 * driver setup() requests
456 * @ep_list: List of other endpoints supported by the device.
457 * @speed: Speed of current connection to USB host.
Kishon Vijay Abraham I747a0a52015-02-23 18:39:58 +0530458 * @max_speed: Maximal speed the UDC can handle. UDC must support this
459 * and all slower speeds.
York Sun472d5462013-04-01 11:29:11 -0700460 * @is_dualspeed: true if the controller supports both high and full speed
Remy Bohmer23cd1382009-07-29 18:18:43 +0200461 * operation. If it does, the gadget driver must also support both.
York Sun472d5462013-04-01 11:29:11 -0700462 * @is_otg: true if the USB device port uses a Mini-AB jack, so that the
Remy Bohmer23cd1382009-07-29 18:18:43 +0200463 * gadget driver must provide a USB OTG descriptor.
York Sun472d5462013-04-01 11:29:11 -0700464 * @is_a_peripheral: false unless is_otg, the "A" end of a USB cable
Remy Bohmer23cd1382009-07-29 18:18:43 +0200465 * is in the Mini-AB jack, and HNP has been used to switch roles
466 * so that the "A" device currently acts as A-Peripheral, not A-Host.
467 * @a_hnp_support: OTG device feature flag, indicating that the A-Host
468 * supports HNP at this port.
469 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
470 * only supports HNP on a different root port.
471 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
472 * enabled HNP support.
473 * @name: Identifies the controller hardware type. Used in diagnostics
474 * and sometimes configuration.
475 * @dev: Driver model state for this abstract device.
Kishon Vijay Abraham I747a0a52015-02-23 18:39:58 +0530476 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
477 * MaxPacketSize.
Remy Bohmer23cd1382009-07-29 18:18:43 +0200478 *
479 * Gadgets have a mostly-portable "gadget driver" implementing device
480 * functions, handling all usb configurations and interfaces. Gadget
481 * drivers talk to hardware-specific code indirectly, through ops vectors.
482 * That insulates the gadget driver from hardware details, and packages
483 * the hardware endpoints through generic i/o queues. The "usb_gadget"
484 * and "usb_ep" interfaces provide that insulation from the hardware.
485 *
486 * Except for the driver data, all fields in this structure are
487 * read-only to the gadget driver. That driver data is part of the
488 * "driver model" infrastructure in 2.6 (and later) kernels, and for
489 * earlier systems is grouped in a similar structure that's not known
490 * to the rest of the kernel.
491 *
492 * Values of the three OTG device feature flags are updated before the
493 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
494 * driver suspend() calls. They are valid only when is_otg, and when the
495 * device is acting as a B-Peripheral (so is_a_peripheral is false).
496 */
497struct usb_gadget {
498 /* readonly to gadget driver */
499 const struct usb_gadget_ops *ops;
500 struct usb_ep *ep0;
501 struct list_head ep_list; /* of usb_ep */
502 enum usb_device_speed speed;
Kishon Vijay Abraham I747a0a52015-02-23 18:39:58 +0530503 enum usb_device_speed max_speed;
Kishon Vijay Abraham I45d93372015-02-23 18:39:47 +0530504 enum usb_device_state state;
Remy Bohmer23cd1382009-07-29 18:18:43 +0200505 unsigned is_dualspeed:1;
506 unsigned is_otg:1;
507 unsigned is_a_peripheral:1;
508 unsigned b_hnp_enable:1;
509 unsigned a_hnp_support:1;
510 unsigned a_alt_hnp_support:1;
511 const char *name;
512 struct device dev;
Kishon Vijay Abraham I747a0a52015-02-23 18:39:58 +0530513 unsigned quirk_ep_out_aligned_size:1;
Remy Bohmer23cd1382009-07-29 18:18:43 +0200514};
515
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400516static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200517{
518 gadget->dev.driver_data = data;
519}
520
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400521static inline void *get_gadget_data(struct usb_gadget *gadget)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200522{
523 return gadget->dev.driver_data;
524}
525
Lukasz Majewski4eec44d2012-05-02 13:11:37 +0200526static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
527{
528 return container_of(dev, struct usb_gadget, dev);
529}
530
Remy Bohmer23cd1382009-07-29 18:18:43 +0200531/* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400532#define gadget_for_each_ep(tmp, gadget) \
Remy Bohmer23cd1382009-07-29 18:18:43 +0200533 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
534
535
536/**
537 * gadget_is_dualspeed - return true iff the hardware handles high speed
538 * @g: controller that might support both high and full speeds
539 */
540static inline int gadget_is_dualspeed(struct usb_gadget *g)
541{
542#ifdef CONFIG_USB_GADGET_DUALSPEED
543 /* runtime test would check "g->is_dualspeed" ... that might be
544 * useful to work around hardware bugs, but is mostly pointless
545 */
546 return 1;
547#else
548 return 0;
549#endif
550}
551
552/**
553 * gadget_is_otg - return true iff the hardware is OTG-ready
554 * @g: controller that might have a Mini-AB connector
555 *
556 * This is a runtime test, since kernels with a USB-OTG stack sometimes
557 * run on boards which only have a Mini-B (or Mini-A) connector.
558 */
559static inline int gadget_is_otg(struct usb_gadget *g)
560{
561#ifdef CONFIG_USB_OTG
562 return g->is_otg;
563#else
564 return 0;
565#endif
566}
567
Remy Bohmer23cd1382009-07-29 18:18:43 +0200568/**
569 * usb_gadget_frame_number - returns the current frame number
570 * @gadget: controller that reports the frame number
571 *
572 * Returns the usb frame number, normally eleven bits from a SOF packet,
573 * or negative errno if this device doesn't support this capability.
574 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400575static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200576{
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400577 return gadget->ops->get_frame(gadget);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200578}
579
580/**
581 * usb_gadget_wakeup - tries to wake up the host connected to this gadget
582 * @gadget: controller used to wake up the host
583 *
584 * Returns zero on success, else negative error code if the hardware
585 * doesn't support such attempts, or its support has not been enabled
586 * by the usb host. Drivers must return device descriptors that report
587 * their ability to support this, or hosts won't enable it.
588 *
589 * This may also try to use SRP to wake the host and start enumeration,
590 * even if OTG isn't otherwise in use. OTG devices may also start
591 * remote wakeup even when hosts don't explicitly enable it.
592 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400593static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200594{
595 if (!gadget->ops->wakeup)
596 return -EOPNOTSUPP;
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400597 return gadget->ops->wakeup(gadget);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200598}
599
600/**
601 * usb_gadget_set_selfpowered - sets the device selfpowered feature.
602 * @gadget:the device being declared as self-powered
603 *
604 * this affects the device status reported by the hardware driver
605 * to reflect that it now has a local power supply.
606 *
607 * returns zero on success, else negative errno.
608 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400609static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200610{
611 if (!gadget->ops->set_selfpowered)
612 return -EOPNOTSUPP;
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400613 return gadget->ops->set_selfpowered(gadget, 1);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200614}
615
616/**
617 * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
618 * @gadget:the device being declared as bus-powered
619 *
620 * this affects the device status reported by the hardware driver.
621 * some hardware may not support bus-powered operation, in which
622 * case this feature's value can never change.
623 *
624 * returns zero on success, else negative errno.
625 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400626static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200627{
628 if (!gadget->ops->set_selfpowered)
629 return -EOPNOTSUPP;
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400630 return gadget->ops->set_selfpowered(gadget, 0);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200631}
632
633/**
634 * usb_gadget_vbus_connect - Notify controller that VBUS is powered
635 * @gadget:The device which now has VBUS power.
636 *
637 * This call is used by a driver for an external transceiver (or GPIO)
638 * that detects a VBUS power session starting. Common responses include
639 * resuming the controller, activating the D+ (or D-) pullup to let the
640 * host detect that a USB device is attached, and starting to draw power
641 * (8mA or possibly more, especially after SET_CONFIGURATION).
642 *
643 * Returns zero on success, else negative errno.
644 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400645static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200646{
647 if (!gadget->ops->vbus_session)
648 return -EOPNOTSUPP;
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400649 return gadget->ops->vbus_session(gadget, 1);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200650}
651
652/**
653 * usb_gadget_vbus_draw - constrain controller's VBUS power usage
654 * @gadget:The device whose VBUS usage is being described
655 * @mA:How much current to draw, in milliAmperes. This should be twice
656 * the value listed in the configuration descriptor bMaxPower field.
657 *
658 * This call is used by gadget drivers during SET_CONFIGURATION calls,
659 * reporting how much power the device may consume. For example, this
660 * could affect how quickly batteries are recharged.
661 *
662 * Returns zero on success, else negative errno.
663 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400664static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200665{
666 if (!gadget->ops->vbus_draw)
667 return -EOPNOTSUPP;
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400668 return gadget->ops->vbus_draw(gadget, mA);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200669}
670
671/**
672 * usb_gadget_vbus_disconnect - notify controller about VBUS session end
673 * @gadget:the device whose VBUS supply is being described
674 *
675 * This call is used by a driver for an external transceiver (or GPIO)
676 * that detects a VBUS power session ending. Common responses include
677 * reversing everything done in usb_gadget_vbus_connect().
678 *
679 * Returns zero on success, else negative errno.
680 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400681static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200682{
683 if (!gadget->ops->vbus_session)
684 return -EOPNOTSUPP;
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400685 return gadget->ops->vbus_session(gadget, 0);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200686}
687
688/**
689 * usb_gadget_connect - software-controlled connect to USB host
690 * @gadget:the peripheral being connected
691 *
692 * Enables the D+ (or potentially D-) pullup. The host will start
693 * enumerating this gadget when the pullup is active and a VBUS session
694 * is active (the link is powered). This pullup is always enabled unless
695 * usb_gadget_disconnect() has been used to disable it.
696 *
697 * Returns zero on success, else negative errno.
698 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400699static inline int usb_gadget_connect(struct usb_gadget *gadget)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200700{
701 if (!gadget->ops->pullup)
702 return -EOPNOTSUPP;
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400703 return gadget->ops->pullup(gadget, 1);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200704}
705
706/**
707 * usb_gadget_disconnect - software-controlled disconnect from USB host
708 * @gadget:the peripheral being disconnected
709 *
710 * Disables the D+ (or potentially D-) pullup, which the host may see
711 * as a disconnect (when a VBUS session is active). Not all systems
712 * support software pullup controls.
713 *
714 * This routine may be used during the gadget driver bind() call to prevent
715 * the peripheral from ever being visible to the USB host, unless later
716 * usb_gadget_connect() is called. For example, user mode components may
717 * need to be activated before the system can talk to hosts.
718 *
719 * Returns zero on success, else negative errno.
720 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400721static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
Remy Bohmer23cd1382009-07-29 18:18:43 +0200722{
723 if (!gadget->ops->pullup)
724 return -EOPNOTSUPP;
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400725 return gadget->ops->pullup(gadget, 0);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200726}
727
728
Remy Bohmer23cd1382009-07-29 18:18:43 +0200729/*-------------------------------------------------------------------------*/
730
731/**
732 * struct usb_gadget_driver - driver for usb 'slave' devices
Kishon Vijay Abraham I45d93372015-02-23 18:39:47 +0530733 * @function: String describing the gadget's function
Remy Bohmer23cd1382009-07-29 18:18:43 +0200734 * @speed: Highest speed the driver handles.
735 * @bind: Invoked when the driver is bound to a gadget, usually
736 * after registering the driver.
737 * At that point, ep0 is fully initialized, and ep_list holds
738 * the currently-available endpoints.
739 * Called in a context that permits sleeping.
740 * @setup: Invoked for ep0 control requests that aren't handled by
741 * the hardware level driver. Most calls must be handled by
742 * the gadget driver, including descriptor and configuration
743 * management. The 16 bit members of the setup data are in
744 * USB byte order. Called in_interrupt; this may not sleep. Driver
745 * queues a response to ep0, or returns negative to stall.
746 * @disconnect: Invoked after all transfers have been stopped,
747 * when the host is disconnected. May be called in_interrupt; this
748 * may not sleep. Some devices can't detect disconnect, so this might
749 * not be called except as part of controller shutdown.
750 * @unbind: Invoked when the driver is unbound from a gadget,
751 * usually from rmmod (after a disconnect is reported).
752 * Called in a context that permits sleeping.
753 * @suspend: Invoked on USB suspend. May be called in_interrupt.
754 * @resume: Invoked on USB resume. May be called in_interrupt.
Kishon Vijay Abraham I45d93372015-02-23 18:39:47 +0530755 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers
756 * and should be called in_interrupt.
Remy Bohmer23cd1382009-07-29 18:18:43 +0200757 *
758 * Devices are disabled till a gadget driver successfully bind()s, which
759 * means the driver will handle setup() requests needed to enumerate (and
760 * meet "chapter 9" requirements) then do some useful work.
761 *
762 * If gadget->is_otg is true, the gadget driver must provide an OTG
763 * descriptor during enumeration, or else fail the bind() call. In such
764 * cases, no USB traffic may flow until both bind() returns without
765 * having called usb_gadget_disconnect(), and the USB host stack has
766 * initialized.
767 *
768 * Drivers use hardware-specific knowledge to configure the usb hardware.
769 * endpoint addressing is only one of several hardware characteristics that
770 * are in descriptors the ep0 implementation returns from setup() calls.
771 *
772 * Except for ep0 implementation, most driver code shouldn't need change to
773 * run on top of different usb controllers. It'll use endpoints set up by
774 * that ep0 implementation.
775 *
776 * The usb controller driver handles a few standard usb requests. Those
777 * include set_address, and feature flags for devices, interfaces, and
778 * endpoints (the get_status, set_feature, and clear_feature requests).
779 *
780 * Accordingly, the driver's setup() callback must always implement all
781 * get_descriptor requests, returning at least a device descriptor and
782 * a configuration descriptor. Drivers must make sure the endpoint
783 * descriptors match any hardware constraints. Some hardware also constrains
784 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
785 *
786 * The driver's setup() callback must also implement set_configuration,
787 * and should also implement set_interface, get_configuration, and
788 * get_interface. Setting a configuration (or interface) is where
789 * endpoints should be activated or (config 0) shut down.
790 *
791 * (Note that only the default control endpoint is supported. Neither
792 * hosts nor devices generally support control traffic except to ep0.)
793 *
794 * Most devices will ignore USB suspend/resume operations, and so will
795 * not provide those callbacks. However, some may need to change modes
796 * when the host is not longer directing those activities. For example,
797 * local controls (buttons, dials, etc) may need to be re-enabled since
798 * the (remote) host can't do that any longer; or an error state might
799 * be cleared, to make the device behave identically whether or not
800 * power is maintained.
801 */
802struct usb_gadget_driver {
Kishon Vijay Abraham I45d93372015-02-23 18:39:47 +0530803 char *function;
Remy Bohmer23cd1382009-07-29 18:18:43 +0200804 enum usb_device_speed speed;
805 int (*bind)(struct usb_gadget *);
806 void (*unbind)(struct usb_gadget *);
807 int (*setup)(struct usb_gadget *,
808 const struct usb_ctrlrequest *);
809 void (*disconnect)(struct usb_gadget *);
810 void (*suspend)(struct usb_gadget *);
811 void (*resume)(struct usb_gadget *);
Kishon Vijay Abraham I45d93372015-02-23 18:39:47 +0530812 void (*reset)(struct usb_gadget *);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200813};
814
815
Remy Bohmer23cd1382009-07-29 18:18:43 +0200816/*-------------------------------------------------------------------------*/
817
818/* driver modules register and unregister, as usual.
819 * these calls must be made in a context that can sleep.
820 *
821 * these will usually be implemented directly by the hardware-dependent
822 * usb bus interface driver, which will only support a single driver.
823 */
824
825/**
826 * usb_gadget_register_driver - register a gadget driver
827 * @driver:the driver being registered
828 *
829 * Call this in your gadget driver's module initialization function,
830 * to tell the underlying usb controller driver about your driver.
831 * The driver's bind() function will be called to bind it to a
832 * gadget before this registration call returns. It's expected that
833 * the bind() functions will be in init sections.
834 * This function must be called in a context that can sleep.
835 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400836int usb_gadget_register_driver(struct usb_gadget_driver *driver);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200837
838/**
839 * usb_gadget_unregister_driver - unregister a gadget driver
840 * @driver:the driver being unregistered
841 *
842 * Call this in your gadget driver's module cleanup function,
843 * to tell the underlying usb controller that your driver is
844 * going away. If the controller is connected to a USB host,
845 * it will first disconnect(). The driver is also requested
846 * to unbind() and clean up any device state, before this procedure
847 * finally returns. It's expected that the unbind() functions
848 * will in in exit sections, so may not be linked in some kernels.
849 * This function must be called in a context that can sleep.
850 */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400851int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200852
Kishon Vijay Abraham I45d93372015-02-23 18:39:47 +0530853int usb_add_gadget_udc_release(struct device *parent,
854 struct usb_gadget *gadget, void (*release)(struct device *dev));
855int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
856void usb_del_gadget_udc(struct usb_gadget *gadget);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200857/*-------------------------------------------------------------------------*/
858
859/* utility to simplify dealing with string descriptors */
860
861/**
Remy Bohmer23cd1382009-07-29 18:18:43 +0200862 * struct usb_gadget_strings - a set of USB strings in a given language
863 * @language:identifies the strings' language (0x0409 for en-us)
864 * @strings:array of strings with their ids
865 *
866 * If you're using usb_gadget_get_string(), use this to wrap all the
867 * strings for a given language.
868 */
869struct usb_gadget_strings {
870 u16 language; /* 0x0409 for en-us */
871 struct usb_string *strings;
872};
873
874/* put descriptor for string with that id into buf (buflen >= 256) */
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400875int usb_gadget_get_string(struct usb_gadget_strings *table, int id, u8 *buf);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200876
877/*-------------------------------------------------------------------------*/
878
879/* utility to simplify managing config descriptors */
880
881/* write vector of descriptors into buffer */
882int usb_descriptor_fillbuf(void *, unsigned,
883 const struct usb_descriptor_header **);
884
885/* build config descriptor from single descriptor vector */
886int usb_gadget_config_buf(const struct usb_config_descriptor *config,
887 void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
888
889/*-------------------------------------------------------------------------*/
Kishon Vijay Abraham I45d93372015-02-23 18:39:47 +0530890/* utility to simplify map/unmap of usb_requests to/from DMA */
891
892extern int usb_gadget_map_request(struct usb_gadget *gadget,
893 struct usb_request *req, int is_in);
894
895extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
896 struct usb_request *req, int is_in);
897
898/*-------------------------------------------------------------------------*/
899
900/* utility to set gadget state properly */
901
902extern void usb_gadget_set_state(struct usb_gadget *gadget,
903 enum usb_device_state state);
904
905/*-------------------------------------------------------------------------*/
906
907/* utility to tell udc core that the bus reset occurs */
908extern void usb_gadget_udc_reset(struct usb_gadget *gadget,
909 struct usb_gadget_driver *driver);
910
911/*-------------------------------------------------------------------------*/
912
913/* utility to give requests back to the gadget layer */
914
915extern void usb_gadget_giveback_request(struct usb_ep *ep,
916 struct usb_request *req);
917
918/*-------------------------------------------------------------------------*/
Remy Bohmer23cd1382009-07-29 18:18:43 +0200919
920/* utility wrapping a simple endpoint selection policy */
921
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400922extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
Remy Bohmer23cd1382009-07-29 18:18:43 +0200923 struct usb_endpoint_descriptor *);
924
Vitaly Kuzmichev6142e0a2010-09-13 18:37:11 +0400925extern void usb_ep_autoconfig_reset(struct usb_gadget *);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200926
Kishon Vijay Abraham I2d48aa62015-02-23 18:40:23 +0530927extern int usb_gadget_handle_interrupts(int index);
Remy Bohmer23cd1382009-07-29 18:18:43 +0200928
929#endif /* __LINUX_USB_GADGET_H */