Merge tag 'for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/kishon/linux...
[deliverable/linux.git] / include / linux / usb / gadget.h
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
15 #ifndef __LINUX_USB_GADGET_H
16 #define __LINUX_USB_GADGET_H
17
18 #include <linux/device.h>
19 #include <linux/errno.h>
20 #include <linux/init.h>
21 #include <linux/list.h>
22 #include <linux/slab.h>
23 #include <linux/scatterlist.h>
24 #include <linux/types.h>
25 #include <linux/workqueue.h>
26 #include <linux/usb/ch9.h>
27
28 struct usb_ep;
29
30 /**
31 * struct usb_request - describes one i/o request
32 * @buf: Buffer used for data. Always provide this; some controllers
33 * only use PIO, or don't use DMA for some endpoints.
34 * @dma: DMA address corresponding to 'buf'. If you don't set this
35 * field, and the usb controller needs one, it is responsible
36 * for mapping and unmapping the buffer.
37 * @sg: a scatterlist for SG-capable controllers.
38 * @num_sgs: number of SG entries
39 * @num_mapped_sgs: number of SG entries mapped to DMA (internal)
40 * @length: Length of that data
41 * @stream_id: The stream id, when USB3.0 bulk streams are being used
42 * @no_interrupt: If true, hints that no completion irq is needed.
43 * Helpful sometimes with deep request queues that are handled
44 * directly by DMA controllers.
45 * @zero: If true, when writing data, makes the last packet be "short"
46 * by adding a zero length packet as needed;
47 * @short_not_ok: When reading data, makes short packets be
48 * treated as errors (queue stops advancing till cleanup).
49 * @complete: Function called when request completes, so this request and
50 * its buffer may be re-used. The function will always be called with
51 * interrupts disabled, and it must not sleep.
52 * Reads terminate with a short packet, or when the buffer fills,
53 * whichever comes first. When writes terminate, some data bytes
54 * will usually still be in flight (often in a hardware fifo).
55 * Errors (for reads or writes) stop the queue from advancing
56 * until the completion function returns, so that any transfers
57 * invalidated by the error may first be dequeued.
58 * @context: For use by the completion callback
59 * @list: For use by the gadget driver.
60 * @status: Reports completion code, zero or a negative errno.
61 * Normally, faults block the transfer queue from advancing until
62 * the completion callback returns.
63 * Code "-ESHUTDOWN" indicates completion caused by device disconnect,
64 * or when the driver disabled the endpoint.
65 * @actual: Reports bytes transferred to/from the buffer. For reads (OUT
66 * transfers) this may be less than the requested length. If the
67 * short_not_ok flag is set, short reads are treated as errors
68 * even when status otherwise indicates successful completion.
69 * Note that for writes (IN transfers) some data bytes may still
70 * reside in a device-side FIFO when the request is reported as
71 * complete.
72 *
73 * These are allocated/freed through the endpoint they're used with. The
74 * hardware's driver can add extra per-request data to the memory it returns,
75 * which often avoids separate memory allocations (potential failures),
76 * later when the request is queued.
77 *
78 * Request flags affect request handling, such as whether a zero length
79 * packet is written (the "zero" flag), whether a short read should be
80 * treated as an error (blocking request queue advance, the "short_not_ok"
81 * flag), or hinting that an interrupt is not required (the "no_interrupt"
82 * flag, for use with deep request queues).
83 *
84 * Bulk endpoints can use any size buffers, and can also be used for interrupt
85 * transfers. interrupt-only endpoints can be much less functional.
86 *
87 * NOTE: this is analogous to 'struct urb' on the host side, except that
88 * it's thinner and promotes more pre-allocation.
89 */
90
91 struct usb_request {
92 void *buf;
93 unsigned length;
94 dma_addr_t dma;
95
96 struct scatterlist *sg;
97 unsigned num_sgs;
98 unsigned num_mapped_sgs;
99
100 unsigned stream_id:16;
101 unsigned no_interrupt:1;
102 unsigned zero:1;
103 unsigned short_not_ok:1;
104
105 void (*complete)(struct usb_ep *ep,
106 struct usb_request *req);
107 void *context;
108 struct list_head list;
109
110 int status;
111 unsigned actual;
112 };
113
114 /*-------------------------------------------------------------------------*/
115
116 /* endpoint-specific parts of the api to the usb controller hardware.
117 * unlike the urb model, (de)multiplexing layers are not required.
118 * (so this api could slash overhead if used on the host side...)
119 *
120 * note that device side usb controllers commonly differ in how many
121 * endpoints they support, as well as their capabilities.
122 */
123 struct usb_ep_ops {
124 int (*enable) (struct usb_ep *ep,
125 const struct usb_endpoint_descriptor *desc);
126 int (*disable) (struct usb_ep *ep);
127
128 struct usb_request *(*alloc_request) (struct usb_ep *ep,
129 gfp_t gfp_flags);
130 void (*free_request) (struct usb_ep *ep, struct usb_request *req);
131
132 int (*queue) (struct usb_ep *ep, struct usb_request *req,
133 gfp_t gfp_flags);
134 int (*dequeue) (struct usb_ep *ep, struct usb_request *req);
135
136 int (*set_halt) (struct usb_ep *ep, int value);
137 int (*set_wedge) (struct usb_ep *ep);
138
139 int (*fifo_status) (struct usb_ep *ep);
140 void (*fifo_flush) (struct usb_ep *ep);
141 };
142
143 /**
144 * struct usb_ep - device side representation of USB endpoint
145 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk"
146 * @ops: Function pointers used to access hardware-specific operations.
147 * @ep_list:the gadget's ep_list holds all of its endpoints
148 * @maxpacket:The maximum packet size used on this endpoint. The initial
149 * value can sometimes be reduced (hardware allowing), according to
150 * the endpoint descriptor used to configure the endpoint.
151 * @maxpacket_limit:The maximum packet size value which can be handled by this
152 * endpoint. It's set once by UDC driver when endpoint is initialized, and
153 * should not be changed. Should not be confused with maxpacket.
154 * @max_streams: The maximum number of streams supported
155 * by this EP (0 - 16, actual number is 2^n)
156 * @mult: multiplier, 'mult' value for SS Isoc EPs
157 * @maxburst: the maximum number of bursts supported by this EP (for usb3)
158 * @driver_data:for use by the gadget driver.
159 * @address: used to identify the endpoint when finding descriptor that
160 * matches connection speed
161 * @desc: endpoint descriptor. This pointer is set before the endpoint is
162 * enabled and remains valid until the endpoint is disabled.
163 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion
164 * descriptor that is used to configure the endpoint
165 *
166 * the bus controller driver lists all the general purpose endpoints in
167 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list,
168 * and is accessed only in response to a driver setup() callback.
169 */
170 struct usb_ep {
171 void *driver_data;
172
173 const char *name;
174 const struct usb_ep_ops *ops;
175 struct list_head ep_list;
176 unsigned maxpacket:16;
177 unsigned maxpacket_limit:16;
178 unsigned max_streams:16;
179 unsigned mult:2;
180 unsigned maxburst:5;
181 u8 address;
182 const struct usb_endpoint_descriptor *desc;
183 const struct usb_ss_ep_comp_descriptor *comp_desc;
184 };
185
186 /*-------------------------------------------------------------------------*/
187
188 /**
189 * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
190 * @ep:the endpoint being configured
191 * @maxpacket_limit:value of maximum packet size limit
192 *
193 * This function should be used only in UDC drivers to initialize endpoint
194 * (usually in probe function).
195 */
196 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
197 unsigned maxpacket_limit)
198 {
199 ep->maxpacket_limit = maxpacket_limit;
200 ep->maxpacket = maxpacket_limit;
201 }
202
203 /**
204 * usb_ep_enable - configure endpoint, making it usable
205 * @ep:the endpoint being configured. may not be the endpoint named "ep0".
206 * drivers discover endpoints through the ep_list of a usb_gadget.
207 *
208 * When configurations are set, or when interface settings change, the driver
209 * will enable or disable the relevant endpoints. while it is enabled, an
210 * endpoint may be used for i/o until the driver receives a disconnect() from
211 * the host or until the endpoint is disabled.
212 *
213 * the ep0 implementation (which calls this routine) must ensure that the
214 * hardware capabilities of each endpoint match the descriptor provided
215 * for it. for example, an endpoint named "ep2in-bulk" would be usable
216 * for interrupt transfers as well as bulk, but it likely couldn't be used
217 * for iso transfers or for endpoint 14. some endpoints are fully
218 * configurable, with more generic names like "ep-a". (remember that for
219 * USB, "in" means "towards the USB master".)
220 *
221 * returns zero, or a negative error code.
222 */
223 static inline int usb_ep_enable(struct usb_ep *ep)
224 {
225 return ep->ops->enable(ep, ep->desc);
226 }
227
228 /**
229 * usb_ep_disable - endpoint is no longer usable
230 * @ep:the endpoint being unconfigured. may not be the endpoint named "ep0".
231 *
232 * no other task may be using this endpoint when this is called.
233 * any pending and uncompleted requests will complete with status
234 * indicating disconnect (-ESHUTDOWN) before this call returns.
235 * gadget drivers must call usb_ep_enable() again before queueing
236 * requests to the endpoint.
237 *
238 * returns zero, or a negative error code.
239 */
240 static inline int usb_ep_disable(struct usb_ep *ep)
241 {
242 return ep->ops->disable(ep);
243 }
244
245 /**
246 * usb_ep_alloc_request - allocate a request object to use with this endpoint
247 * @ep:the endpoint to be used with with the request
248 * @gfp_flags:GFP_* flags to use
249 *
250 * Request objects must be allocated with this call, since they normally
251 * need controller-specific setup and may even need endpoint-specific
252 * resources such as allocation of DMA descriptors.
253 * Requests may be submitted with usb_ep_queue(), and receive a single
254 * completion callback. Free requests with usb_ep_free_request(), when
255 * they are no longer needed.
256 *
257 * Returns the request, or null if one could not be allocated.
258 */
259 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
260 gfp_t gfp_flags)
261 {
262 return ep->ops->alloc_request(ep, gfp_flags);
263 }
264
265 /**
266 * usb_ep_free_request - frees a request object
267 * @ep:the endpoint associated with the request
268 * @req:the request being freed
269 *
270 * Reverses the effect of usb_ep_alloc_request().
271 * Caller guarantees the request is not queued, and that it will
272 * no longer be requeued (or otherwise used).
273 */
274 static inline void usb_ep_free_request(struct usb_ep *ep,
275 struct usb_request *req)
276 {
277 ep->ops->free_request(ep, req);
278 }
279
280 /**
281 * usb_ep_queue - queues (submits) an I/O request to an endpoint.
282 * @ep:the endpoint associated with the request
283 * @req:the request being submitted
284 * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
285 * pre-allocate all necessary memory with the request.
286 *
287 * This tells the device controller to perform the specified request through
288 * that endpoint (reading or writing a buffer). When the request completes,
289 * including being canceled by usb_ep_dequeue(), the request's completion
290 * routine is called to return the request to the driver. Any endpoint
291 * (except control endpoints like ep0) may have more than one transfer
292 * request queued; they complete in FIFO order. Once a gadget driver
293 * submits a request, that request may not be examined or modified until it
294 * is given back to that driver through the completion callback.
295 *
296 * Each request is turned into one or more packets. The controller driver
297 * never merges adjacent requests into the same packet. OUT transfers
298 * will sometimes use data that's already buffered in the hardware.
299 * Drivers can rely on the fact that the first byte of the request's buffer
300 * always corresponds to the first byte of some USB packet, for both
301 * IN and OUT transfers.
302 *
303 * Bulk endpoints can queue any amount of data; the transfer is packetized
304 * automatically. The last packet will be short if the request doesn't fill it
305 * out completely. Zero length packets (ZLPs) should be avoided in portable
306 * protocols since not all usb hardware can successfully handle zero length
307 * packets. (ZLPs may be explicitly written, and may be implicitly written if
308 * the request 'zero' flag is set.) Bulk endpoints may also be used
309 * for interrupt transfers; but the reverse is not true, and some endpoints
310 * won't support every interrupt transfer. (Such as 768 byte packets.)
311 *
312 * Interrupt-only endpoints are less functional than bulk endpoints, for
313 * example by not supporting queueing or not handling buffers that are
314 * larger than the endpoint's maxpacket size. They may also treat data
315 * toggle differently.
316 *
317 * Control endpoints ... after getting a setup() callback, the driver queues
318 * one response (even if it would be zero length). That enables the
319 * status ack, after transferring data as specified in the response. Setup
320 * functions may return negative error codes to generate protocol stalls.
321 * (Note that some USB device controllers disallow protocol stall responses
322 * in some cases.) When control responses are deferred (the response is
323 * written after the setup callback returns), then usb_ep_set_halt() may be
324 * used on ep0 to trigger protocol stalls. Depending on the controller,
325 * it may not be possible to trigger a status-stage protocol stall when the
326 * data stage is over, that is, from within the response's completion
327 * routine.
328 *
329 * For periodic endpoints, like interrupt or isochronous ones, the usb host
330 * arranges to poll once per interval, and the gadget driver usually will
331 * have queued some data to transfer at that time.
332 *
333 * Returns zero, or a negative error code. Endpoints that are not enabled
334 * report errors; errors will also be
335 * reported when the usb peripheral is disconnected.
336 */
337 static inline int usb_ep_queue(struct usb_ep *ep,
338 struct usb_request *req, gfp_t gfp_flags)
339 {
340 return ep->ops->queue(ep, req, gfp_flags);
341 }
342
343 /**
344 * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
345 * @ep:the endpoint associated with the request
346 * @req:the request being canceled
347 *
348 * If the request is still active on the endpoint, it is dequeued and its
349 * completion routine is called (with status -ECONNRESET); else a negative
350 * error code is returned. This is guaranteed to happen before the call to
351 * usb_ep_dequeue() returns.
352 *
353 * Note that some hardware can't clear out write fifos (to unlink the request
354 * at the head of the queue) except as part of disconnecting from usb. Such
355 * restrictions prevent drivers from supporting configuration changes,
356 * even to configuration zero (a "chapter 9" requirement).
357 */
358 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
359 {
360 return ep->ops->dequeue(ep, req);
361 }
362
363 /**
364 * usb_ep_set_halt - sets the endpoint halt feature.
365 * @ep: the non-isochronous endpoint being stalled
366 *
367 * Use this to stall an endpoint, perhaps as an error report.
368 * Except for control endpoints,
369 * the endpoint stays halted (will not stream any data) until the host
370 * clears this feature; drivers may need to empty the endpoint's request
371 * queue first, to make sure no inappropriate transfers happen.
372 *
373 * Note that while an endpoint CLEAR_FEATURE will be invisible to the
374 * gadget driver, a SET_INTERFACE will not be. To reset endpoints for the
375 * current altsetting, see usb_ep_clear_halt(). When switching altsettings,
376 * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
377 *
378 * Returns zero, or a negative error code. On success, this call sets
379 * underlying hardware state that blocks data transfers.
380 * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
381 * transfer requests are still queued, or if the controller hardware
382 * (usually a FIFO) still holds bytes that the host hasn't collected.
383 */
384 static inline int usb_ep_set_halt(struct usb_ep *ep)
385 {
386 return ep->ops->set_halt(ep, 1);
387 }
388
389 /**
390 * usb_ep_clear_halt - clears endpoint halt, and resets toggle
391 * @ep:the bulk or interrupt endpoint being reset
392 *
393 * Use this when responding to the standard usb "set interface" request,
394 * for endpoints that aren't reconfigured, after clearing any other state
395 * in the endpoint's i/o queue.
396 *
397 * Returns zero, or a negative error code. On success, this call clears
398 * the underlying hardware state reflecting endpoint halt and data toggle.
399 * Note that some hardware can't support this request (like pxa2xx_udc),
400 * and accordingly can't correctly implement interface altsettings.
401 */
402 static inline int usb_ep_clear_halt(struct usb_ep *ep)
403 {
404 return ep->ops->set_halt(ep, 0);
405 }
406
407 /**
408 * usb_ep_set_wedge - sets the halt feature and ignores clear requests
409 * @ep: the endpoint being wedged
410 *
411 * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT)
412 * requests. If the gadget driver clears the halt status, it will
413 * automatically unwedge the endpoint.
414 *
415 * Returns zero on success, else negative errno.
416 */
417 static inline int
418 usb_ep_set_wedge(struct usb_ep *ep)
419 {
420 if (ep->ops->set_wedge)
421 return ep->ops->set_wedge(ep);
422 else
423 return ep->ops->set_halt(ep, 1);
424 }
425
426 /**
427 * usb_ep_fifo_status - returns number of bytes in fifo, or error
428 * @ep: the endpoint whose fifo status is being checked.
429 *
430 * FIFO endpoints may have "unclaimed data" in them in certain cases,
431 * such as after aborted transfers. Hosts may not have collected all
432 * the IN data written by the gadget driver (and reported by a request
433 * completion). The gadget driver may not have collected all the data
434 * written OUT to it by the host. Drivers that need precise handling for
435 * fault reporting or recovery may need to use this call.
436 *
437 * This returns the number of such bytes in the fifo, or a negative
438 * errno if the endpoint doesn't use a FIFO or doesn't support such
439 * precise handling.
440 */
441 static inline int usb_ep_fifo_status(struct usb_ep *ep)
442 {
443 if (ep->ops->fifo_status)
444 return ep->ops->fifo_status(ep);
445 else
446 return -EOPNOTSUPP;
447 }
448
449 /**
450 * usb_ep_fifo_flush - flushes contents of a fifo
451 * @ep: the endpoint whose fifo is being flushed.
452 *
453 * This call may be used to flush the "unclaimed data" that may exist in
454 * an endpoint fifo after abnormal transaction terminations. The call
455 * must never be used except when endpoint is not being used for any
456 * protocol translation.
457 */
458 static inline void usb_ep_fifo_flush(struct usb_ep *ep)
459 {
460 if (ep->ops->fifo_flush)
461 ep->ops->fifo_flush(ep);
462 }
463
464
465 /*-------------------------------------------------------------------------*/
466
467 struct usb_dcd_config_params {
468 __u8 bU1devExitLat; /* U1 Device exit Latency */
469 #define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */
470 __le16 bU2DevExitLat; /* U2 Device exit Latency */
471 #define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */
472 };
473
474
475 struct usb_gadget;
476 struct usb_gadget_driver;
477 struct usb_udc;
478
479 /* the rest of the api to the controller hardware: device operations,
480 * which don't involve endpoints (or i/o).
481 */
482 struct usb_gadget_ops {
483 int (*get_frame)(struct usb_gadget *);
484 int (*wakeup)(struct usb_gadget *);
485 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
486 int (*vbus_session) (struct usb_gadget *, int is_active);
487 int (*vbus_draw) (struct usb_gadget *, unsigned mA);
488 int (*pullup) (struct usb_gadget *, int is_on);
489 int (*ioctl)(struct usb_gadget *,
490 unsigned code, unsigned long param);
491 void (*get_config_params)(struct usb_dcd_config_params *);
492 int (*udc_start)(struct usb_gadget *,
493 struct usb_gadget_driver *);
494 int (*udc_stop)(struct usb_gadget *);
495 };
496
497 /**
498 * struct usb_gadget - represents a usb slave device
499 * @work: (internal use) Workqueue to be used for sysfs_notify()
500 * @udc: struct usb_udc pointer for this gadget
501 * @ops: Function pointers used to access hardware-specific operations.
502 * @ep0: Endpoint zero, used when reading or writing responses to
503 * driver setup() requests
504 * @ep_list: List of other endpoints supported by the device.
505 * @speed: Speed of current connection to USB host.
506 * @max_speed: Maximal speed the UDC can handle. UDC must support this
507 * and all slower speeds.
508 * @state: the state we are now (attached, suspended, configured, etc)
509 * @name: Identifies the controller hardware type. Used in diagnostics
510 * and sometimes configuration.
511 * @dev: Driver model state for this abstract device.
512 * @out_epnum: last used out ep number
513 * @in_epnum: last used in ep number
514 * @sg_supported: true if we can handle scatter-gather
515 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
516 * gadget driver must provide a USB OTG descriptor.
517 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable
518 * is in the Mini-AB jack, and HNP has been used to switch roles
519 * so that the "A" device currently acts as A-Peripheral, not A-Host.
520 * @a_hnp_support: OTG device feature flag, indicating that the A-Host
521 * supports HNP at this port.
522 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
523 * only supports HNP on a different root port.
524 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
525 * enabled HNP support.
526 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
527 * MaxPacketSize.
528 * @is_selfpowered: if the gadget is self-powered.
529 *
530 * Gadgets have a mostly-portable "gadget driver" implementing device
531 * functions, handling all usb configurations and interfaces. Gadget
532 * drivers talk to hardware-specific code indirectly, through ops vectors.
533 * That insulates the gadget driver from hardware details, and packages
534 * the hardware endpoints through generic i/o queues. The "usb_gadget"
535 * and "usb_ep" interfaces provide that insulation from the hardware.
536 *
537 * Except for the driver data, all fields in this structure are
538 * read-only to the gadget driver. That driver data is part of the
539 * "driver model" infrastructure in 2.6 (and later) kernels, and for
540 * earlier systems is grouped in a similar structure that's not known
541 * to the rest of the kernel.
542 *
543 * Values of the three OTG device feature flags are updated before the
544 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
545 * driver suspend() calls. They are valid only when is_otg, and when the
546 * device is acting as a B-Peripheral (so is_a_peripheral is false).
547 */
548 struct usb_gadget {
549 struct work_struct work;
550 struct usb_udc *udc;
551 /* readonly to gadget driver */
552 const struct usb_gadget_ops *ops;
553 struct usb_ep *ep0;
554 struct list_head ep_list; /* of usb_ep */
555 enum usb_device_speed speed;
556 enum usb_device_speed max_speed;
557 enum usb_device_state state;
558 const char *name;
559 struct device dev;
560 unsigned out_epnum;
561 unsigned in_epnum;
562
563 unsigned sg_supported:1;
564 unsigned is_otg:1;
565 unsigned is_a_peripheral:1;
566 unsigned b_hnp_enable:1;
567 unsigned a_hnp_support:1;
568 unsigned a_alt_hnp_support:1;
569 unsigned quirk_ep_out_aligned_size:1;
570 unsigned is_selfpowered:1;
571 };
572 #define work_to_gadget(w) (container_of((w), struct usb_gadget, work))
573
574 static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
575 { dev_set_drvdata(&gadget->dev, data); }
576 static inline void *get_gadget_data(struct usb_gadget *gadget)
577 { return dev_get_drvdata(&gadget->dev); }
578 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
579 {
580 return container_of(dev, struct usb_gadget, dev);
581 }
582
583 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
584 #define gadget_for_each_ep(tmp, gadget) \
585 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
586
587
588 /**
589 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget
590 * requires quirk_ep_out_aligned_size, otherwise reguens len.
591 * @g: controller to check for quirk
592 * @ep: the endpoint whose maxpacketsize is used to align @len
593 * @len: buffer size's length to align to @ep's maxpacketsize
594 *
595 * This helper is used in case it's required for any reason to check and maybe
596 * align buffer's size to an ep's maxpacketsize.
597 */
598 static inline size_t
599 usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len)
600 {
601 return !g->quirk_ep_out_aligned_size ? len :
602 round_up(len, (size_t)ep->desc->wMaxPacketSize);
603 }
604
605 /**
606 * gadget_is_dualspeed - return true iff the hardware handles high speed
607 * @g: controller that might support both high and full speeds
608 */
609 static inline int gadget_is_dualspeed(struct usb_gadget *g)
610 {
611 return g->max_speed >= USB_SPEED_HIGH;
612 }
613
614 /**
615 * gadget_is_superspeed() - return true if the hardware handles superspeed
616 * @g: controller that might support superspeed
617 */
618 static inline int gadget_is_superspeed(struct usb_gadget *g)
619 {
620 return g->max_speed >= USB_SPEED_SUPER;
621 }
622
623 /**
624 * gadget_is_otg - return true iff the hardware is OTG-ready
625 * @g: controller that might have a Mini-AB connector
626 *
627 * This is a runtime test, since kernels with a USB-OTG stack sometimes
628 * run on boards which only have a Mini-B (or Mini-A) connector.
629 */
630 static inline int gadget_is_otg(struct usb_gadget *g)
631 {
632 #ifdef CONFIG_USB_OTG
633 return g->is_otg;
634 #else
635 return 0;
636 #endif
637 }
638
639 /**
640 * usb_gadget_frame_number - returns the current frame number
641 * @gadget: controller that reports the frame number
642 *
643 * Returns the usb frame number, normally eleven bits from a SOF packet,
644 * or negative errno if this device doesn't support this capability.
645 */
646 static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
647 {
648 return gadget->ops->get_frame(gadget);
649 }
650
651 /**
652 * usb_gadget_wakeup - tries to wake up the host connected to this gadget
653 * @gadget: controller used to wake up the host
654 *
655 * Returns zero on success, else negative error code if the hardware
656 * doesn't support such attempts, or its support has not been enabled
657 * by the usb host. Drivers must return device descriptors that report
658 * their ability to support this, or hosts won't enable it.
659 *
660 * This may also try to use SRP to wake the host and start enumeration,
661 * even if OTG isn't otherwise in use. OTG devices may also start
662 * remote wakeup even when hosts don't explicitly enable it.
663 */
664 static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
665 {
666 if (!gadget->ops->wakeup)
667 return -EOPNOTSUPP;
668 return gadget->ops->wakeup(gadget);
669 }
670
671 /**
672 * usb_gadget_set_selfpowered - sets the device selfpowered feature.
673 * @gadget:the device being declared as self-powered
674 *
675 * this affects the device status reported by the hardware driver
676 * to reflect that it now has a local power supply.
677 *
678 * returns zero on success, else negative errno.
679 */
680 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
681 {
682 if (!gadget->ops->set_selfpowered)
683 return -EOPNOTSUPP;
684 return gadget->ops->set_selfpowered(gadget, 1);
685 }
686
687 /**
688 * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
689 * @gadget:the device being declared as bus-powered
690 *
691 * this affects the device status reported by the hardware driver.
692 * some hardware may not support bus-powered operation, in which
693 * case this feature's value can never change.
694 *
695 * returns zero on success, else negative errno.
696 */
697 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
698 {
699 if (!gadget->ops->set_selfpowered)
700 return -EOPNOTSUPP;
701 return gadget->ops->set_selfpowered(gadget, 0);
702 }
703
704 /**
705 * usb_gadget_vbus_connect - Notify controller that VBUS is powered
706 * @gadget:The device which now has VBUS power.
707 * Context: can sleep
708 *
709 * This call is used by a driver for an external transceiver (or GPIO)
710 * that detects a VBUS power session starting. Common responses include
711 * resuming the controller, activating the D+ (or D-) pullup to let the
712 * host detect that a USB device is attached, and starting to draw power
713 * (8mA or possibly more, especially after SET_CONFIGURATION).
714 *
715 * Returns zero on success, else negative errno.
716 */
717 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
718 {
719 if (!gadget->ops->vbus_session)
720 return -EOPNOTSUPP;
721 return gadget->ops->vbus_session(gadget, 1);
722 }
723
724 /**
725 * usb_gadget_vbus_draw - constrain controller's VBUS power usage
726 * @gadget:The device whose VBUS usage is being described
727 * @mA:How much current to draw, in milliAmperes. This should be twice
728 * the value listed in the configuration descriptor bMaxPower field.
729 *
730 * This call is used by gadget drivers during SET_CONFIGURATION calls,
731 * reporting how much power the device may consume. For example, this
732 * could affect how quickly batteries are recharged.
733 *
734 * Returns zero on success, else negative errno.
735 */
736 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
737 {
738 if (!gadget->ops->vbus_draw)
739 return -EOPNOTSUPP;
740 return gadget->ops->vbus_draw(gadget, mA);
741 }
742
743 /**
744 * usb_gadget_vbus_disconnect - notify controller about VBUS session end
745 * @gadget:the device whose VBUS supply is being described
746 * Context: can sleep
747 *
748 * This call is used by a driver for an external transceiver (or GPIO)
749 * that detects a VBUS power session ending. Common responses include
750 * reversing everything done in usb_gadget_vbus_connect().
751 *
752 * Returns zero on success, else negative errno.
753 */
754 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
755 {
756 if (!gadget->ops->vbus_session)
757 return -EOPNOTSUPP;
758 return gadget->ops->vbus_session(gadget, 0);
759 }
760
761 /**
762 * usb_gadget_connect - software-controlled connect to USB host
763 * @gadget:the peripheral being connected
764 *
765 * Enables the D+ (or potentially D-) pullup. The host will start
766 * enumerating this gadget when the pullup is active and a VBUS session
767 * is active (the link is powered). This pullup is always enabled unless
768 * usb_gadget_disconnect() has been used to disable it.
769 *
770 * Returns zero on success, else negative errno.
771 */
772 static inline int usb_gadget_connect(struct usb_gadget *gadget)
773 {
774 if (!gadget->ops->pullup)
775 return -EOPNOTSUPP;
776 return gadget->ops->pullup(gadget, 1);
777 }
778
779 /**
780 * usb_gadget_disconnect - software-controlled disconnect from USB host
781 * @gadget:the peripheral being disconnected
782 *
783 * Disables the D+ (or potentially D-) pullup, which the host may see
784 * as a disconnect (when a VBUS session is active). Not all systems
785 * support software pullup controls.
786 *
787 * This routine may be used during the gadget driver bind() call to prevent
788 * the peripheral from ever being visible to the USB host, unless later
789 * usb_gadget_connect() is called. For example, user mode components may
790 * need to be activated before the system can talk to hosts.
791 *
792 * Returns zero on success, else negative errno.
793 */
794 static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
795 {
796 if (!gadget->ops->pullup)
797 return -EOPNOTSUPP;
798 return gadget->ops->pullup(gadget, 0);
799 }
800
801
802 /*-------------------------------------------------------------------------*/
803
804 /**
805 * struct usb_gadget_driver - driver for usb 'slave' devices
806 * @function: String describing the gadget's function
807 * @max_speed: Highest speed the driver handles.
808 * @setup: Invoked for ep0 control requests that aren't handled by
809 * the hardware level driver. Most calls must be handled by
810 * the gadget driver, including descriptor and configuration
811 * management. The 16 bit members of the setup data are in
812 * USB byte order. Called in_interrupt; this may not sleep. Driver
813 * queues a response to ep0, or returns negative to stall.
814 * @disconnect: Invoked after all transfers have been stopped,
815 * when the host is disconnected. May be called in_interrupt; this
816 * may not sleep. Some devices can't detect disconnect, so this might
817 * not be called except as part of controller shutdown.
818 * @bind: the driver's bind callback
819 * @unbind: Invoked when the driver is unbound from a gadget,
820 * usually from rmmod (after a disconnect is reported).
821 * Called in a context that permits sleeping.
822 * @suspend: Invoked on USB suspend. May be called in_interrupt.
823 * @resume: Invoked on USB resume. May be called in_interrupt.
824 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers
825 * and should be called in_interrupt.
826 * @driver: Driver model state for this driver.
827 *
828 * Devices are disabled till a gadget driver successfully bind()s, which
829 * means the driver will handle setup() requests needed to enumerate (and
830 * meet "chapter 9" requirements) then do some useful work.
831 *
832 * If gadget->is_otg is true, the gadget driver must provide an OTG
833 * descriptor during enumeration, or else fail the bind() call. In such
834 * cases, no USB traffic may flow until both bind() returns without
835 * having called usb_gadget_disconnect(), and the USB host stack has
836 * initialized.
837 *
838 * Drivers use hardware-specific knowledge to configure the usb hardware.
839 * endpoint addressing is only one of several hardware characteristics that
840 * are in descriptors the ep0 implementation returns from setup() calls.
841 *
842 * Except for ep0 implementation, most driver code shouldn't need change to
843 * run on top of different usb controllers. It'll use endpoints set up by
844 * that ep0 implementation.
845 *
846 * The usb controller driver handles a few standard usb requests. Those
847 * include set_address, and feature flags for devices, interfaces, and
848 * endpoints (the get_status, set_feature, and clear_feature requests).
849 *
850 * Accordingly, the driver's setup() callback must always implement all
851 * get_descriptor requests, returning at least a device descriptor and
852 * a configuration descriptor. Drivers must make sure the endpoint
853 * descriptors match any hardware constraints. Some hardware also constrains
854 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
855 *
856 * The driver's setup() callback must also implement set_configuration,
857 * and should also implement set_interface, get_configuration, and
858 * get_interface. Setting a configuration (or interface) is where
859 * endpoints should be activated or (config 0) shut down.
860 *
861 * (Note that only the default control endpoint is supported. Neither
862 * hosts nor devices generally support control traffic except to ep0.)
863 *
864 * Most devices will ignore USB suspend/resume operations, and so will
865 * not provide those callbacks. However, some may need to change modes
866 * when the host is not longer directing those activities. For example,
867 * local controls (buttons, dials, etc) may need to be re-enabled since
868 * the (remote) host can't do that any longer; or an error state might
869 * be cleared, to make the device behave identically whether or not
870 * power is maintained.
871 */
872 struct usb_gadget_driver {
873 char *function;
874 enum usb_device_speed max_speed;
875 int (*bind)(struct usb_gadget *gadget,
876 struct usb_gadget_driver *driver);
877 void (*unbind)(struct usb_gadget *);
878 int (*setup)(struct usb_gadget *,
879 const struct usb_ctrlrequest *);
880 void (*disconnect)(struct usb_gadget *);
881 void (*suspend)(struct usb_gadget *);
882 void (*resume)(struct usb_gadget *);
883 void (*reset)(struct usb_gadget *);
884
885 /* FIXME support safe rmmod */
886 struct device_driver driver;
887 };
888
889
890
891 /*-------------------------------------------------------------------------*/
892
893 /* driver modules register and unregister, as usual.
894 * these calls must be made in a context that can sleep.
895 *
896 * these will usually be implemented directly by the hardware-dependent
897 * usb bus interface driver, which will only support a single driver.
898 */
899
900 /**
901 * usb_gadget_probe_driver - probe a gadget driver
902 * @driver: the driver being registered
903 * Context: can sleep
904 *
905 * Call this in your gadget driver's module initialization function,
906 * to tell the underlying usb controller driver about your driver.
907 * The @bind() function will be called to bind it to a gadget before this
908 * registration call returns. It's expected that the @bind() function will
909 * be in init sections.
910 */
911 int usb_gadget_probe_driver(struct usb_gadget_driver *driver);
912
913 /**
914 * usb_gadget_unregister_driver - unregister a gadget driver
915 * @driver:the driver being unregistered
916 * Context: can sleep
917 *
918 * Call this in your gadget driver's module cleanup function,
919 * to tell the underlying usb controller that your driver is
920 * going away. If the controller is connected to a USB host,
921 * it will first disconnect(). The driver is also requested
922 * to unbind() and clean up any device state, before this procedure
923 * finally returns. It's expected that the unbind() functions
924 * will in in exit sections, so may not be linked in some kernels.
925 */
926 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
927
928 extern int usb_add_gadget_udc_release(struct device *parent,
929 struct usb_gadget *gadget, void (*release)(struct device *dev));
930 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
931 extern void usb_del_gadget_udc(struct usb_gadget *gadget);
932 extern int usb_udc_attach_driver(const char *name,
933 struct usb_gadget_driver *driver);
934
935 /*-------------------------------------------------------------------------*/
936
937 /* utility to simplify dealing with string descriptors */
938
939 /**
940 * struct usb_string - wraps a C string and its USB id
941 * @id:the (nonzero) ID for this string
942 * @s:the string, in UTF-8 encoding
943 *
944 * If you're using usb_gadget_get_string(), use this to wrap a string
945 * together with its ID.
946 */
947 struct usb_string {
948 u8 id;
949 const char *s;
950 };
951
952 /**
953 * struct usb_gadget_strings - a set of USB strings in a given language
954 * @language:identifies the strings' language (0x0409 for en-us)
955 * @strings:array of strings with their ids
956 *
957 * If you're using usb_gadget_get_string(), use this to wrap all the
958 * strings for a given language.
959 */
960 struct usb_gadget_strings {
961 u16 language; /* 0x0409 for en-us */
962 struct usb_string *strings;
963 };
964
965 struct usb_gadget_string_container {
966 struct list_head list;
967 u8 *stash[0];
968 };
969
970 /* put descriptor for string with that id into buf (buflen >= 256) */
971 int usb_gadget_get_string(struct usb_gadget_strings *table, int id, u8 *buf);
972
973 /*-------------------------------------------------------------------------*/
974
975 /* utility to simplify managing config descriptors */
976
977 /* write vector of descriptors into buffer */
978 int usb_descriptor_fillbuf(void *, unsigned,
979 const struct usb_descriptor_header **);
980
981 /* build config descriptor from single descriptor vector */
982 int usb_gadget_config_buf(const struct usb_config_descriptor *config,
983 void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
984
985 /* copy a NULL-terminated vector of descriptors */
986 struct usb_descriptor_header **usb_copy_descriptors(
987 struct usb_descriptor_header **);
988
989 /**
990 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors()
991 * @v: vector of descriptors
992 */
993 static inline void usb_free_descriptors(struct usb_descriptor_header **v)
994 {
995 kfree(v);
996 }
997
998 struct usb_function;
999 int usb_assign_descriptors(struct usb_function *f,
1000 struct usb_descriptor_header **fs,
1001 struct usb_descriptor_header **hs,
1002 struct usb_descriptor_header **ss);
1003 void usb_free_all_descriptors(struct usb_function *f);
1004
1005 /*-------------------------------------------------------------------------*/
1006
1007 /* utility to simplify map/unmap of usb_requests to/from DMA */
1008
1009 extern int usb_gadget_map_request(struct usb_gadget *gadget,
1010 struct usb_request *req, int is_in);
1011
1012 extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
1013 struct usb_request *req, int is_in);
1014
1015 /*-------------------------------------------------------------------------*/
1016
1017 /* utility to set gadget state properly */
1018
1019 extern void usb_gadget_set_state(struct usb_gadget *gadget,
1020 enum usb_device_state state);
1021
1022 /*-------------------------------------------------------------------------*/
1023
1024 /* utility to tell udc core that the bus reset occurs */
1025 extern void usb_gadget_udc_reset(struct usb_gadget *gadget,
1026 struct usb_gadget_driver *driver);
1027
1028 /*-------------------------------------------------------------------------*/
1029
1030 /* utility to give requests back to the gadget layer */
1031
1032 extern void usb_gadget_giveback_request(struct usb_ep *ep,
1033 struct usb_request *req);
1034
1035 /*-------------------------------------------------------------------------*/
1036
1037 /* utility to update vbus status for udc core, it may be scheduled */
1038 extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status);
1039
1040 /*-------------------------------------------------------------------------*/
1041
1042 /* utility wrapping a simple endpoint selection policy */
1043
1044 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
1045 struct usb_endpoint_descriptor *);
1046
1047
1048 extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *,
1049 struct usb_endpoint_descriptor *,
1050 struct usb_ss_ep_comp_descriptor *);
1051
1052 extern void usb_ep_autoconfig_reset(struct usb_gadget *);
1053
1054 #endif /* __LINUX_USB_GADGET_H */
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