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1da177e4 LT |
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 | #ifdef __KERNEL__ | |
19 | ||
20 | struct usb_ep; | |
21 | ||
22 | /** | |
23 | * struct usb_request - describes one i/o request | |
24 | * @buf: Buffer used for data. Always provide this; some controllers | |
25 | * only use PIO, or don't use DMA for some endpoints. | |
26 | * @dma: DMA address corresponding to 'buf'. If you don't set this | |
27 | * field, and the usb controller needs one, it is responsible | |
28 | * for mapping and unmapping the buffer. | |
29 | * @length: Length of that data | |
30 | * @no_interrupt: If true, hints that no completion irq is needed. | |
31 | * Helpful sometimes with deep request queues that are handled | |
32 | * directly by DMA controllers. | |
33 | * @zero: If true, when writing data, makes the last packet be "short" | |
34 | * by adding a zero length packet as needed; | |
35 | * @short_not_ok: When reading data, makes short packets be | |
36 | * treated as errors (queue stops advancing till cleanup). | |
37 | * @complete: Function called when request completes, so this request and | |
38 | * its buffer may be re-used. | |
39 | * Reads terminate with a short packet, or when the buffer fills, | |
40 | * whichever comes first. When writes terminate, some data bytes | |
41 | * will usually still be in flight (often in a hardware fifo). | |
42 | * Errors (for reads or writes) stop the queue from advancing | |
43 | * until the completion function returns, so that any transfers | |
44 | * invalidated by the error may first be dequeued. | |
45 | * @context: For use by the completion callback | |
46 | * @list: For use by the gadget driver. | |
47 | * @status: Reports completion code, zero or a negative errno. | |
48 | * Normally, faults block the transfer queue from advancing until | |
49 | * the completion callback returns. | |
50 | * Code "-ESHUTDOWN" indicates completion caused by device disconnect, | |
51 | * or when the driver disabled the endpoint. | |
52 | * @actual: Reports bytes transferred to/from the buffer. For reads (OUT | |
53 | * transfers) this may be less than the requested length. If the | |
54 | * short_not_ok flag is set, short reads are treated as errors | |
55 | * even when status otherwise indicates successful completion. | |
56 | * Note that for writes (IN transfers) some data bytes may still | |
57 | * reside in a device-side FIFO when the request is reported as | |
58 | * complete. | |
59 | * | |
60 | * These are allocated/freed through the endpoint they're used with. The | |
61 | * hardware's driver can add extra per-request data to the memory it returns, | |
62 | * which often avoids separate memory allocations (potential failures), | |
63 | * later when the request is queued. | |
64 | * | |
65 | * Request flags affect request handling, such as whether a zero length | |
66 | * packet is written (the "zero" flag), whether a short read should be | |
67 | * treated as an error (blocking request queue advance, the "short_not_ok" | |
68 | * flag), or hinting that an interrupt is not required (the "no_interrupt" | |
69 | * flag, for use with deep request queues). | |
70 | * | |
71 | * Bulk endpoints can use any size buffers, and can also be used for interrupt | |
72 | * transfers. interrupt-only endpoints can be much less functional. | |
73 | */ | |
74 | // NOTE this is analagous to 'struct urb' on the host side, | |
75 | // except that it's thinner and promotes more pre-allocation. | |
76 | ||
77 | struct usb_request { | |
78 | void *buf; | |
79 | unsigned length; | |
80 | dma_addr_t dma; | |
81 | ||
82 | unsigned no_interrupt:1; | |
83 | unsigned zero:1; | |
84 | unsigned short_not_ok:1; | |
85 | ||
86 | void (*complete)(struct usb_ep *ep, | |
87 | struct usb_request *req); | |
88 | void *context; | |
89 | struct list_head list; | |
90 | ||
91 | int status; | |
92 | unsigned actual; | |
93 | }; | |
94 | ||
95 | /*-------------------------------------------------------------------------*/ | |
96 | ||
97 | /* endpoint-specific parts of the api to the usb controller hardware. | |
98 | * unlike the urb model, (de)multiplexing layers are not required. | |
99 | * (so this api could slash overhead if used on the host side...) | |
100 | * | |
101 | * note that device side usb controllers commonly differ in how many | |
102 | * endpoints they support, as well as their capabilities. | |
103 | */ | |
104 | struct usb_ep_ops { | |
105 | int (*enable) (struct usb_ep *ep, | |
106 | const struct usb_endpoint_descriptor *desc); | |
107 | int (*disable) (struct usb_ep *ep); | |
108 | ||
109 | struct usb_request *(*alloc_request) (struct usb_ep *ep, | |
55016f10 | 110 | gfp_t gfp_flags); |
1da177e4 LT |
111 | void (*free_request) (struct usb_ep *ep, struct usb_request *req); |
112 | ||
113 | void *(*alloc_buffer) (struct usb_ep *ep, unsigned bytes, | |
55016f10 | 114 | dma_addr_t *dma, gfp_t gfp_flags); |
1da177e4 LT |
115 | void (*free_buffer) (struct usb_ep *ep, void *buf, dma_addr_t dma, |
116 | unsigned bytes); | |
117 | // NOTE: on 2.6, drivers may also use dma_map() and | |
118 | // dma_sync_single_*() to directly manage dma overhead. | |
119 | ||
120 | int (*queue) (struct usb_ep *ep, struct usb_request *req, | |
55016f10 | 121 | gfp_t gfp_flags); |
1da177e4 LT |
122 | int (*dequeue) (struct usb_ep *ep, struct usb_request *req); |
123 | ||
124 | int (*set_halt) (struct usb_ep *ep, int value); | |
125 | int (*fifo_status) (struct usb_ep *ep); | |
126 | void (*fifo_flush) (struct usb_ep *ep); | |
127 | }; | |
128 | ||
129 | /** | |
130 | * struct usb_ep - device side representation of USB endpoint | |
131 | * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk" | |
132 | * @ops: Function pointers used to access hardware-specific operations. | |
133 | * @ep_list:the gadget's ep_list holds all of its endpoints | |
134 | * @maxpacket:The maximum packet size used on this endpoint. The initial | |
135 | * value can sometimes be reduced (hardware allowing), according to | |
136 | * the endpoint descriptor used to configure the endpoint. | |
137 | * @driver_data:for use by the gadget driver. all other fields are | |
138 | * read-only to gadget drivers. | |
139 | * | |
140 | * the bus controller driver lists all the general purpose endpoints in | |
141 | * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list, | |
142 | * and is accessed only in response to a driver setup() callback. | |
143 | */ | |
144 | struct usb_ep { | |
145 | void *driver_data; | |
146 | ||
147 | const char *name; | |
148 | const struct usb_ep_ops *ops; | |
149 | struct list_head ep_list; | |
150 | unsigned maxpacket:16; | |
151 | }; | |
152 | ||
153 | /*-------------------------------------------------------------------------*/ | |
154 | ||
155 | /** | |
156 | * usb_ep_enable - configure endpoint, making it usable | |
157 | * @ep:the endpoint being configured. may not be the endpoint named "ep0". | |
158 | * drivers discover endpoints through the ep_list of a usb_gadget. | |
159 | * @desc:descriptor for desired behavior. caller guarantees this pointer | |
160 | * remains valid until the endpoint is disabled; the data byte order | |
161 | * is little-endian (usb-standard). | |
162 | * | |
163 | * when configurations are set, or when interface settings change, the driver | |
164 | * will enable or disable the relevant endpoints. while it is enabled, an | |
165 | * endpoint may be used for i/o until the driver receives a disconnect() from | |
166 | * the host or until the endpoint is disabled. | |
167 | * | |
168 | * the ep0 implementation (which calls this routine) must ensure that the | |
169 | * hardware capabilities of each endpoint match the descriptor provided | |
170 | * for it. for example, an endpoint named "ep2in-bulk" would be usable | |
171 | * for interrupt transfers as well as bulk, but it likely couldn't be used | |
172 | * for iso transfers or for endpoint 14. some endpoints are fully | |
173 | * configurable, with more generic names like "ep-a". (remember that for | |
174 | * USB, "in" means "towards the USB master".) | |
175 | * | |
176 | * returns zero, or a negative error code. | |
177 | */ | |
178 | static inline int | |
179 | usb_ep_enable (struct usb_ep *ep, const struct usb_endpoint_descriptor *desc) | |
180 | { | |
181 | return ep->ops->enable (ep, desc); | |
182 | } | |
183 | ||
184 | /** | |
185 | * usb_ep_disable - endpoint is no longer usable | |
186 | * @ep:the endpoint being unconfigured. may not be the endpoint named "ep0". | |
187 | * | |
188 | * no other task may be using this endpoint when this is called. | |
189 | * any pending and uncompleted requests will complete with status | |
190 | * indicating disconnect (-ESHUTDOWN) before this call returns. | |
191 | * gadget drivers must call usb_ep_enable() again before queueing | |
192 | * requests to the endpoint. | |
193 | * | |
194 | * returns zero, or a negative error code. | |
195 | */ | |
196 | static inline int | |
197 | usb_ep_disable (struct usb_ep *ep) | |
198 | { | |
199 | return ep->ops->disable (ep); | |
200 | } | |
201 | ||
202 | /** | |
203 | * usb_ep_alloc_request - allocate a request object to use with this endpoint | |
204 | * @ep:the endpoint to be used with with the request | |
205 | * @gfp_flags:GFP_* flags to use | |
206 | * | |
207 | * Request objects must be allocated with this call, since they normally | |
208 | * need controller-specific setup and may even need endpoint-specific | |
209 | * resources such as allocation of DMA descriptors. | |
210 | * Requests may be submitted with usb_ep_queue(), and receive a single | |
211 | * completion callback. Free requests with usb_ep_free_request(), when | |
212 | * they are no longer needed. | |
213 | * | |
214 | * Returns the request, or null if one could not be allocated. | |
215 | */ | |
216 | static inline struct usb_request * | |
55016f10 | 217 | usb_ep_alloc_request (struct usb_ep *ep, gfp_t gfp_flags) |
1da177e4 LT |
218 | { |
219 | return ep->ops->alloc_request (ep, gfp_flags); | |
220 | } | |
221 | ||
222 | /** | |
223 | * usb_ep_free_request - frees a request object | |
224 | * @ep:the endpoint associated with the request | |
225 | * @req:the request being freed | |
226 | * | |
227 | * Reverses the effect of usb_ep_alloc_request(). | |
228 | * Caller guarantees the request is not queued, and that it will | |
229 | * no longer be requeued (or otherwise used). | |
230 | */ | |
231 | static inline void | |
232 | usb_ep_free_request (struct usb_ep *ep, struct usb_request *req) | |
233 | { | |
234 | ep->ops->free_request (ep, req); | |
235 | } | |
236 | ||
237 | /** | |
238 | * usb_ep_alloc_buffer - allocate an I/O buffer | |
239 | * @ep:the endpoint associated with the buffer | |
240 | * @len:length of the desired buffer | |
241 | * @dma:pointer to the buffer's DMA address; must be valid | |
242 | * @gfp_flags:GFP_* flags to use | |
243 | * | |
244 | * Returns a new buffer, or null if one could not be allocated. | |
245 | * The buffer is suitably aligned for dma, if that endpoint uses DMA, | |
246 | * and the caller won't have to care about dma-inconsistency | |
247 | * or any hidden "bounce buffer" mechanism. No additional per-request | |
248 | * DMA mapping will be required for such buffers. | |
249 | * Free it later with usb_ep_free_buffer(). | |
250 | * | |
251 | * You don't need to use this call to allocate I/O buffers unless you | |
252 | * want to make sure drivers don't incur costs for such "bounce buffer" | |
253 | * copies or per-request DMA mappings. | |
254 | */ | |
255 | static inline void * | |
256 | usb_ep_alloc_buffer (struct usb_ep *ep, unsigned len, dma_addr_t *dma, | |
55016f10 | 257 | gfp_t gfp_flags) |
1da177e4 LT |
258 | { |
259 | return ep->ops->alloc_buffer (ep, len, dma, gfp_flags); | |
260 | } | |
261 | ||
262 | /** | |
263 | * usb_ep_free_buffer - frees an i/o buffer | |
264 | * @ep:the endpoint associated with the buffer | |
265 | * @buf:CPU view address of the buffer | |
266 | * @dma:the buffer's DMA address | |
267 | * @len:length of the buffer | |
268 | * | |
269 | * reverses the effect of usb_ep_alloc_buffer(). | |
270 | * caller guarantees the buffer will no longer be accessed | |
271 | */ | |
272 | static inline void | |
273 | usb_ep_free_buffer (struct usb_ep *ep, void *buf, dma_addr_t dma, unsigned len) | |
274 | { | |
275 | ep->ops->free_buffer (ep, buf, dma, len); | |
276 | } | |
277 | ||
278 | /** | |
279 | * usb_ep_queue - queues (submits) an I/O request to an endpoint. | |
280 | * @ep:the endpoint associated with the request | |
281 | * @req:the request being submitted | |
282 | * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't | |
283 | * pre-allocate all necessary memory with the request. | |
284 | * | |
285 | * This tells the device controller to perform the specified request through | |
286 | * that endpoint (reading or writing a buffer). When the request completes, | |
287 | * including being canceled by usb_ep_dequeue(), the request's completion | |
288 | * routine is called to return the request to the driver. Any endpoint | |
289 | * (except control endpoints like ep0) may have more than one transfer | |
290 | * request queued; they complete in FIFO order. Once a gadget driver | |
291 | * submits a request, that request may not be examined or modified until it | |
292 | * is given back to that driver through the completion callback. | |
293 | * | |
294 | * Each request is turned into one or more packets. The controller driver | |
295 | * never merges adjacent requests into the same packet. OUT transfers | |
296 | * will sometimes use data that's already buffered in the hardware. | |
297 | * Drivers can rely on the fact that the first byte of the request's buffer | |
298 | * always corresponds to the first byte of some USB packet, for both | |
299 | * IN and OUT transfers. | |
300 | * | |
301 | * Bulk endpoints can queue any amount of data; the transfer is packetized | |
302 | * automatically. The last packet will be short if the request doesn't fill it | |
303 | * out completely. Zero length packets (ZLPs) should be avoided in portable | |
304 | * protocols since not all usb hardware can successfully handle zero length | |
305 | * packets. (ZLPs may be explicitly written, and may be implicitly written if | |
306 | * the request 'zero' flag is set.) Bulk endpoints may also be used | |
307 | * for interrupt transfers; but the reverse is not true, and some endpoints | |
308 | * won't support every interrupt transfer. (Such as 768 byte packets.) | |
309 | * | |
310 | * Interrupt-only endpoints are less functional than bulk endpoints, for | |
311 | * example by not supporting queueing or not handling buffers that are | |
312 | * larger than the endpoint's maxpacket size. They may also treat data | |
313 | * toggle differently. | |
314 | * | |
315 | * Control endpoints ... after getting a setup() callback, the driver queues | |
316 | * one response (even if it would be zero length). That enables the | |
317 | * status ack, after transfering data as specified in the response. Setup | |
318 | * functions may return negative error codes to generate protocol stalls. | |
319 | * (Note that some USB device controllers disallow protocol stall responses | |
320 | * in some cases.) When control responses are deferred (the response is | |
321 | * written after the setup callback returns), then usb_ep_set_halt() may be | |
322 | * used on ep0 to trigger protocol stalls. | |
323 | * | |
324 | * For periodic endpoints, like interrupt or isochronous ones, the usb host | |
325 | * arranges to poll once per interval, and the gadget driver usually will | |
326 | * have queued some data to transfer at that time. | |
327 | * | |
328 | * Returns zero, or a negative error code. Endpoints that are not enabled | |
329 | * report errors; errors will also be | |
330 | * reported when the usb peripheral is disconnected. | |
331 | */ | |
332 | static inline int | |
55016f10 | 333 | usb_ep_queue (struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags) |
1da177e4 LT |
334 | { |
335 | return ep->ops->queue (ep, req, gfp_flags); | |
336 | } | |
337 | ||
338 | /** | |
339 | * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint | |
340 | * @ep:the endpoint associated with the request | |
341 | * @req:the request being canceled | |
342 | * | |
343 | * if the request is still active on the endpoint, it is dequeued and its | |
344 | * completion routine is called (with status -ECONNRESET); else a negative | |
345 | * error code is returned. | |
346 | * | |
347 | * note that some hardware can't clear out write fifos (to unlink the request | |
348 | * at the head of the queue) except as part of disconnecting from usb. such | |
349 | * restrictions prevent drivers from supporting configuration changes, | |
350 | * even to configuration zero (a "chapter 9" requirement). | |
351 | */ | |
352 | static inline int usb_ep_dequeue (struct usb_ep *ep, struct usb_request *req) | |
353 | { | |
354 | return ep->ops->dequeue (ep, req); | |
355 | } | |
356 | ||
357 | /** | |
358 | * usb_ep_set_halt - sets the endpoint halt feature. | |
359 | * @ep: the non-isochronous endpoint being stalled | |
360 | * | |
361 | * Use this to stall an endpoint, perhaps as an error report. | |
362 | * Except for control endpoints, | |
363 | * the endpoint stays halted (will not stream any data) until the host | |
364 | * clears this feature; drivers may need to empty the endpoint's request | |
365 | * queue first, to make sure no inappropriate transfers happen. | |
366 | * | |
367 | * Note that while an endpoint CLEAR_FEATURE will be invisible to the | |
368 | * gadget driver, a SET_INTERFACE will not be. To reset endpoints for the | |
369 | * current altsetting, see usb_ep_clear_halt(). When switching altsettings, | |
370 | * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints. | |
371 | * | |
372 | * Returns zero, or a negative error code. On success, this call sets | |
373 | * underlying hardware state that blocks data transfers. | |
374 | * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any | |
375 | * transfer requests are still queued, or if the controller hardware | |
376 | * (usually a FIFO) still holds bytes that the host hasn't collected. | |
377 | */ | |
378 | static inline int | |
379 | usb_ep_set_halt (struct usb_ep *ep) | |
380 | { | |
381 | return ep->ops->set_halt (ep, 1); | |
382 | } | |
383 | ||
384 | /** | |
385 | * usb_ep_clear_halt - clears endpoint halt, and resets toggle | |
386 | * @ep:the bulk or interrupt endpoint being reset | |
387 | * | |
388 | * Use this when responding to the standard usb "set interface" request, | |
389 | * for endpoints that aren't reconfigured, after clearing any other state | |
390 | * in the endpoint's i/o queue. | |
391 | * | |
392 | * Returns zero, or a negative error code. On success, this call clears | |
393 | * the underlying hardware state reflecting endpoint halt and data toggle. | |
394 | * Note that some hardware can't support this request (like pxa2xx_udc), | |
395 | * and accordingly can't correctly implement interface altsettings. | |
396 | */ | |
397 | static inline int | |
398 | usb_ep_clear_halt (struct usb_ep *ep) | |
399 | { | |
400 | return ep->ops->set_halt (ep, 0); | |
401 | } | |
402 | ||
403 | /** | |
404 | * usb_ep_fifo_status - returns number of bytes in fifo, or error | |
405 | * @ep: the endpoint whose fifo status is being checked. | |
406 | * | |
407 | * FIFO endpoints may have "unclaimed data" in them in certain cases, | |
408 | * such as after aborted transfers. Hosts may not have collected all | |
409 | * the IN data written by the gadget driver (and reported by a request | |
410 | * completion). The gadget driver may not have collected all the data | |
411 | * written OUT to it by the host. Drivers that need precise handling for | |
412 | * fault reporting or recovery may need to use this call. | |
413 | * | |
414 | * This returns the number of such bytes in the fifo, or a negative | |
415 | * errno if the endpoint doesn't use a FIFO or doesn't support such | |
416 | * precise handling. | |
417 | */ | |
418 | static inline int | |
419 | usb_ep_fifo_status (struct usb_ep *ep) | |
420 | { | |
421 | if (ep->ops->fifo_status) | |
422 | return ep->ops->fifo_status (ep); | |
423 | else | |
424 | return -EOPNOTSUPP; | |
425 | } | |
426 | ||
427 | /** | |
428 | * usb_ep_fifo_flush - flushes contents of a fifo | |
429 | * @ep: the endpoint whose fifo is being flushed. | |
430 | * | |
431 | * This call may be used to flush the "unclaimed data" that may exist in | |
432 | * an endpoint fifo after abnormal transaction terminations. The call | |
433 | * must never be used except when endpoint is not being used for any | |
434 | * protocol translation. | |
435 | */ | |
436 | static inline void | |
437 | usb_ep_fifo_flush (struct usb_ep *ep) | |
438 | { | |
439 | if (ep->ops->fifo_flush) | |
440 | ep->ops->fifo_flush (ep); | |
441 | } | |
442 | ||
443 | ||
444 | /*-------------------------------------------------------------------------*/ | |
445 | ||
446 | struct usb_gadget; | |
447 | ||
448 | /* the rest of the api to the controller hardware: device operations, | |
449 | * which don't involve endpoints (or i/o). | |
450 | */ | |
451 | struct usb_gadget_ops { | |
452 | int (*get_frame)(struct usb_gadget *); | |
453 | int (*wakeup)(struct usb_gadget *); | |
454 | int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered); | |
455 | int (*vbus_session) (struct usb_gadget *, int is_active); | |
456 | int (*vbus_draw) (struct usb_gadget *, unsigned mA); | |
457 | int (*pullup) (struct usb_gadget *, int is_on); | |
458 | int (*ioctl)(struct usb_gadget *, | |
459 | unsigned code, unsigned long param); | |
460 | }; | |
461 | ||
462 | /** | |
463 | * struct usb_gadget - represents a usb slave device | |
464 | * @ops: Function pointers used to access hardware-specific operations. | |
465 | * @ep0: Endpoint zero, used when reading or writing responses to | |
466 | * driver setup() requests | |
467 | * @ep_list: List of other endpoints supported by the device. | |
468 | * @speed: Speed of current connection to USB host. | |
469 | * @is_dualspeed: True if the controller supports both high and full speed | |
470 | * operation. If it does, the gadget driver must also support both. | |
471 | * @is_otg: True if the USB device port uses a Mini-AB jack, so that the | |
472 | * gadget driver must provide a USB OTG descriptor. | |
473 | * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable | |
474 | * is in the Mini-AB jack, and HNP has been used to switch roles | |
475 | * so that the "A" device currently acts as A-Peripheral, not A-Host. | |
476 | * @a_hnp_support: OTG device feature flag, indicating that the A-Host | |
477 | * supports HNP at this port. | |
478 | * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host | |
479 | * only supports HNP on a different root port. | |
480 | * @b_hnp_enable: OTG device feature flag, indicating that the A-Host | |
481 | * enabled HNP support. | |
482 | * @name: Identifies the controller hardware type. Used in diagnostics | |
483 | * and sometimes configuration. | |
484 | * @dev: Driver model state for this abstract device. | |
485 | * | |
486 | * Gadgets have a mostly-portable "gadget driver" implementing device | |
487 | * functions, handling all usb configurations and interfaces. Gadget | |
488 | * drivers talk to hardware-specific code indirectly, through ops vectors. | |
489 | * That insulates the gadget driver from hardware details, and packages | |
490 | * the hardware endpoints through generic i/o queues. The "usb_gadget" | |
491 | * and "usb_ep" interfaces provide that insulation from the hardware. | |
492 | * | |
493 | * Except for the driver data, all fields in this structure are | |
494 | * read-only to the gadget driver. That driver data is part of the | |
495 | * "driver model" infrastructure in 2.6 (and later) kernels, and for | |
496 | * earlier systems is grouped in a similar structure that's not known | |
497 | * to the rest of the kernel. | |
498 | * | |
499 | * Values of the three OTG device feature flags are updated before the | |
500 | * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before | |
501 | * driver suspend() calls. They are valid only when is_otg, and when the | |
502 | * device is acting as a B-Peripheral (so is_a_peripheral is false). | |
503 | */ | |
504 | struct usb_gadget { | |
505 | /* readonly to gadget driver */ | |
506 | const struct usb_gadget_ops *ops; | |
507 | struct usb_ep *ep0; | |
508 | struct list_head ep_list; /* of usb_ep */ | |
509 | enum usb_device_speed speed; | |
510 | unsigned is_dualspeed:1; | |
511 | unsigned is_otg:1; | |
512 | unsigned is_a_peripheral:1; | |
513 | unsigned b_hnp_enable:1; | |
514 | unsigned a_hnp_support:1; | |
515 | unsigned a_alt_hnp_support:1; | |
516 | const char *name; | |
517 | struct device dev; | |
518 | }; | |
519 | ||
520 | static inline void set_gadget_data (struct usb_gadget *gadget, void *data) | |
521 | { dev_set_drvdata (&gadget->dev, data); } | |
522 | static inline void *get_gadget_data (struct usb_gadget *gadget) | |
523 | { return dev_get_drvdata (&gadget->dev); } | |
524 | ||
525 | /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */ | |
526 | #define gadget_for_each_ep(tmp,gadget) \ | |
527 | list_for_each_entry(tmp, &(gadget)->ep_list, ep_list) | |
528 | ||
529 | ||
530 | /** | |
531 | * usb_gadget_frame_number - returns the current frame number | |
532 | * @gadget: controller that reports the frame number | |
533 | * | |
534 | * Returns the usb frame number, normally eleven bits from a SOF packet, | |
535 | * or negative errno if this device doesn't support this capability. | |
536 | */ | |
537 | static inline int usb_gadget_frame_number (struct usb_gadget *gadget) | |
538 | { | |
539 | return gadget->ops->get_frame (gadget); | |
540 | } | |
541 | ||
542 | /** | |
543 | * usb_gadget_wakeup - tries to wake up the host connected to this gadget | |
544 | * @gadget: controller used to wake up the host | |
545 | * | |
546 | * Returns zero on success, else negative error code if the hardware | |
547 | * doesn't support such attempts, or its support has not been enabled | |
548 | * by the usb host. Drivers must return device descriptors that report | |
549 | * their ability to support this, or hosts won't enable it. | |
550 | * | |
551 | * This may also try to use SRP to wake the host and start enumeration, | |
552 | * even if OTG isn't otherwise in use. OTG devices may also start | |
553 | * remote wakeup even when hosts don't explicitly enable it. | |
554 | */ | |
555 | static inline int usb_gadget_wakeup (struct usb_gadget *gadget) | |
556 | { | |
557 | if (!gadget->ops->wakeup) | |
558 | return -EOPNOTSUPP; | |
559 | return gadget->ops->wakeup (gadget); | |
560 | } | |
561 | ||
562 | /** | |
563 | * usb_gadget_set_selfpowered - sets the device selfpowered feature. | |
564 | * @gadget:the device being declared as self-powered | |
565 | * | |
566 | * this affects the device status reported by the hardware driver | |
567 | * to reflect that it now has a local power supply. | |
568 | * | |
569 | * returns zero on success, else negative errno. | |
570 | */ | |
571 | static inline int | |
572 | usb_gadget_set_selfpowered (struct usb_gadget *gadget) | |
573 | { | |
574 | if (!gadget->ops->set_selfpowered) | |
575 | return -EOPNOTSUPP; | |
576 | return gadget->ops->set_selfpowered (gadget, 1); | |
577 | } | |
578 | ||
579 | /** | |
580 | * usb_gadget_clear_selfpowered - clear the device selfpowered feature. | |
581 | * @gadget:the device being declared as bus-powered | |
582 | * | |
583 | * this affects the device status reported by the hardware driver. | |
584 | * some hardware may not support bus-powered operation, in which | |
585 | * case this feature's value can never change. | |
586 | * | |
587 | * returns zero on success, else negative errno. | |
588 | */ | |
589 | static inline int | |
590 | usb_gadget_clear_selfpowered (struct usb_gadget *gadget) | |
591 | { | |
592 | if (!gadget->ops->set_selfpowered) | |
593 | return -EOPNOTSUPP; | |
594 | return gadget->ops->set_selfpowered (gadget, 0); | |
595 | } | |
596 | ||
597 | /** | |
598 | * usb_gadget_vbus_connect - Notify controller that VBUS is powered | |
599 | * @gadget:The device which now has VBUS power. | |
600 | * | |
601 | * This call is used by a driver for an external transceiver (or GPIO) | |
602 | * that detects a VBUS power session starting. Common responses include | |
603 | * resuming the controller, activating the D+ (or D-) pullup to let the | |
604 | * host detect that a USB device is attached, and starting to draw power | |
605 | * (8mA or possibly more, especially after SET_CONFIGURATION). | |
606 | * | |
607 | * Returns zero on success, else negative errno. | |
608 | */ | |
609 | static inline int | |
610 | usb_gadget_vbus_connect(struct usb_gadget *gadget) | |
611 | { | |
612 | if (!gadget->ops->vbus_session) | |
613 | return -EOPNOTSUPP; | |
614 | return gadget->ops->vbus_session (gadget, 1); | |
615 | } | |
616 | ||
617 | /** | |
618 | * usb_gadget_vbus_draw - constrain controller's VBUS power usage | |
619 | * @gadget:The device whose VBUS usage is being described | |
620 | * @mA:How much current to draw, in milliAmperes. This should be twice | |
621 | * the value listed in the configuration descriptor bMaxPower field. | |
622 | * | |
623 | * This call is used by gadget drivers during SET_CONFIGURATION calls, | |
624 | * reporting how much power the device may consume. For example, this | |
625 | * could affect how quickly batteries are recharged. | |
626 | * | |
627 | * Returns zero on success, else negative errno. | |
628 | */ | |
629 | static inline int | |
630 | usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA) | |
631 | { | |
632 | if (!gadget->ops->vbus_draw) | |
633 | return -EOPNOTSUPP; | |
634 | return gadget->ops->vbus_draw (gadget, mA); | |
635 | } | |
636 | ||
637 | /** | |
638 | * usb_gadget_vbus_disconnect - notify controller about VBUS session end | |
639 | * @gadget:the device whose VBUS supply is being described | |
640 | * | |
641 | * This call is used by a driver for an external transceiver (or GPIO) | |
642 | * that detects a VBUS power session ending. Common responses include | |
643 | * reversing everything done in usb_gadget_vbus_connect(). | |
644 | * | |
645 | * Returns zero on success, else negative errno. | |
646 | */ | |
647 | static inline int | |
648 | usb_gadget_vbus_disconnect(struct usb_gadget *gadget) | |
649 | { | |
650 | if (!gadget->ops->vbus_session) | |
651 | return -EOPNOTSUPP; | |
652 | return gadget->ops->vbus_session (gadget, 0); | |
653 | } | |
654 | ||
655 | /** | |
656 | * usb_gadget_connect - software-controlled connect to USB host | |
657 | * @gadget:the peripheral being connected | |
658 | * | |
659 | * Enables the D+ (or potentially D-) pullup. The host will start | |
660 | * enumerating this gadget when the pullup is active and a VBUS session | |
661 | * is active (the link is powered). This pullup is always enabled unless | |
662 | * usb_gadget_disconnect() has been used to disable it. | |
663 | * | |
664 | * Returns zero on success, else negative errno. | |
665 | */ | |
666 | static inline int | |
667 | usb_gadget_connect (struct usb_gadget *gadget) | |
668 | { | |
669 | if (!gadget->ops->pullup) | |
670 | return -EOPNOTSUPP; | |
671 | return gadget->ops->pullup (gadget, 1); | |
672 | } | |
673 | ||
674 | /** | |
675 | * usb_gadget_disconnect - software-controlled disconnect from USB host | |
676 | * @gadget:the peripheral being disconnected | |
677 | * | |
678 | * Disables the D+ (or potentially D-) pullup, which the host may see | |
679 | * as a disconnect (when a VBUS session is active). Not all systems | |
680 | * support software pullup controls. | |
681 | * | |
682 | * This routine may be used during the gadget driver bind() call to prevent | |
683 | * the peripheral from ever being visible to the USB host, unless later | |
684 | * usb_gadget_connect() is called. For example, user mode components may | |
685 | * need to be activated before the system can talk to hosts. | |
686 | * | |
687 | * Returns zero on success, else negative errno. | |
688 | */ | |
689 | static inline int | |
690 | usb_gadget_disconnect (struct usb_gadget *gadget) | |
691 | { | |
692 | if (!gadget->ops->pullup) | |
693 | return -EOPNOTSUPP; | |
694 | return gadget->ops->pullup (gadget, 0); | |
695 | } | |
696 | ||
697 | ||
698 | ||
699 | /*-------------------------------------------------------------------------*/ | |
700 | ||
701 | /** | |
702 | * struct usb_gadget_driver - driver for usb 'slave' devices | |
703 | * @function: String describing the gadget's function | |
704 | * @speed: Highest speed the driver handles. | |
705 | * @bind: Invoked when the driver is bound to a gadget, usually | |
706 | * after registering the driver. | |
707 | * At that point, ep0 is fully initialized, and ep_list holds | |
708 | * the currently-available endpoints. | |
709 | * Called in a context that permits sleeping. | |
710 | * @setup: Invoked for ep0 control requests that aren't handled by | |
711 | * the hardware level driver. Most calls must be handled by | |
712 | * the gadget driver, including descriptor and configuration | |
713 | * management. The 16 bit members of the setup data are in | |
1bbc1696 | 714 | * USB byte order. Called in_interrupt; this may not sleep. Driver |
1da177e4 LT |
715 | * queues a response to ep0, or returns negative to stall. |
716 | * @disconnect: Invoked after all transfers have been stopped, | |
717 | * when the host is disconnected. May be called in_interrupt; this | |
718 | * may not sleep. Some devices can't detect disconnect, so this might | |
719 | * not be called except as part of controller shutdown. | |
720 | * @unbind: Invoked when the driver is unbound from a gadget, | |
721 | * usually from rmmod (after a disconnect is reported). | |
722 | * Called in a context that permits sleeping. | |
723 | * @suspend: Invoked on USB suspend. May be called in_interrupt. | |
724 | * @resume: Invoked on USB resume. May be called in_interrupt. | |
725 | * @driver: Driver model state for this driver. | |
726 | * | |
727 | * Devices are disabled till a gadget driver successfully bind()s, which | |
728 | * means the driver will handle setup() requests needed to enumerate (and | |
729 | * meet "chapter 9" requirements) then do some useful work. | |
730 | * | |
731 | * If gadget->is_otg is true, the gadget driver must provide an OTG | |
732 | * descriptor during enumeration, or else fail the bind() call. In such | |
733 | * cases, no USB traffic may flow until both bind() returns without | |
734 | * having called usb_gadget_disconnect(), and the USB host stack has | |
735 | * initialized. | |
736 | * | |
737 | * Drivers use hardware-specific knowledge to configure the usb hardware. | |
738 | * endpoint addressing is only one of several hardware characteristics that | |
739 | * are in descriptors the ep0 implementation returns from setup() calls. | |
740 | * | |
741 | * Except for ep0 implementation, most driver code shouldn't need change to | |
742 | * run on top of different usb controllers. It'll use endpoints set up by | |
743 | * that ep0 implementation. | |
744 | * | |
745 | * The usb controller driver handles a few standard usb requests. Those | |
746 | * include set_address, and feature flags for devices, interfaces, and | |
747 | * endpoints (the get_status, set_feature, and clear_feature requests). | |
748 | * | |
749 | * Accordingly, the driver's setup() callback must always implement all | |
750 | * get_descriptor requests, returning at least a device descriptor and | |
751 | * a configuration descriptor. Drivers must make sure the endpoint | |
752 | * descriptors match any hardware constraints. Some hardware also constrains | |
753 | * other descriptors. (The pxa250 allows only configurations 1, 2, or 3). | |
754 | * | |
755 | * The driver's setup() callback must also implement set_configuration, | |
756 | * and should also implement set_interface, get_configuration, and | |
757 | * get_interface. Setting a configuration (or interface) is where | |
758 | * endpoints should be activated or (config 0) shut down. | |
759 | * | |
760 | * (Note that only the default control endpoint is supported. Neither | |
761 | * hosts nor devices generally support control traffic except to ep0.) | |
762 | * | |
763 | * Most devices will ignore USB suspend/resume operations, and so will | |
764 | * not provide those callbacks. However, some may need to change modes | |
765 | * when the host is not longer directing those activities. For example, | |
766 | * local controls (buttons, dials, etc) may need to be re-enabled since | |
767 | * the (remote) host can't do that any longer; or an error state might | |
768 | * be cleared, to make the device behave identically whether or not | |
769 | * power is maintained. | |
770 | */ | |
771 | struct usb_gadget_driver { | |
772 | char *function; | |
773 | enum usb_device_speed speed; | |
774 | int (*bind)(struct usb_gadget *); | |
775 | void (*unbind)(struct usb_gadget *); | |
776 | int (*setup)(struct usb_gadget *, | |
777 | const struct usb_ctrlrequest *); | |
778 | void (*disconnect)(struct usb_gadget *); | |
779 | void (*suspend)(struct usb_gadget *); | |
780 | void (*resume)(struct usb_gadget *); | |
781 | ||
782 | // FIXME support safe rmmod | |
783 | struct device_driver driver; | |
784 | }; | |
785 | ||
786 | ||
787 | ||
788 | /*-------------------------------------------------------------------------*/ | |
789 | ||
790 | /* driver modules register and unregister, as usual. | |
791 | * these calls must be made in a context that can sleep. | |
792 | * | |
793 | * these will usually be implemented directly by the hardware-dependent | |
794 | * usb bus interface driver, which will only support a single driver. | |
795 | */ | |
796 | ||
797 | /** | |
798 | * usb_gadget_register_driver - register a gadget driver | |
799 | * @driver:the driver being registered | |
800 | * | |
801 | * Call this in your gadget driver's module initialization function, | |
802 | * to tell the underlying usb controller driver about your driver. | |
803 | * The driver's bind() function will be called to bind it to a | |
329af28b DB |
804 | * gadget before this registration call returns. It's expected that |
805 | * the bind() functions will be in init sections. | |
806 | * This function must be called in a context that can sleep. | |
1da177e4 LT |
807 | */ |
808 | int usb_gadget_register_driver (struct usb_gadget_driver *driver); | |
809 | ||
810 | /** | |
811 | * usb_gadget_unregister_driver - unregister a gadget driver | |
812 | * @driver:the driver being unregistered | |
813 | * | |
814 | * Call this in your gadget driver's module cleanup function, | |
815 | * to tell the underlying usb controller that your driver is | |
816 | * going away. If the controller is connected to a USB host, | |
817 | * it will first disconnect(). The driver is also requested | |
818 | * to unbind() and clean up any device state, before this procedure | |
329af28b DB |
819 | * finally returns. It's expected that the unbind() functions |
820 | * will in in exit sections, so may not be linked in some kernels. | |
1da177e4 LT |
821 | * This function must be called in a context that can sleep. |
822 | */ | |
823 | int usb_gadget_unregister_driver (struct usb_gadget_driver *driver); | |
824 | ||
825 | /*-------------------------------------------------------------------------*/ | |
826 | ||
827 | /* utility to simplify dealing with string descriptors */ | |
828 | ||
829 | /** | |
830 | * struct usb_string - wraps a C string and its USB id | |
831 | * @id:the (nonzero) ID for this string | |
832 | * @s:the string, in UTF-8 encoding | |
833 | * | |
834 | * If you're using usb_gadget_get_string(), use this to wrap a string | |
835 | * together with its ID. | |
836 | */ | |
837 | struct usb_string { | |
838 | u8 id; | |
839 | const char *s; | |
840 | }; | |
841 | ||
842 | /** | |
843 | * struct usb_gadget_strings - a set of USB strings in a given language | |
844 | * @language:identifies the strings' language (0x0409 for en-us) | |
845 | * @strings:array of strings with their ids | |
846 | * | |
847 | * If you're using usb_gadget_get_string(), use this to wrap all the | |
848 | * strings for a given language. | |
849 | */ | |
850 | struct usb_gadget_strings { | |
851 | u16 language; /* 0x0409 for en-us */ | |
852 | struct usb_string *strings; | |
853 | }; | |
854 | ||
855 | /* put descriptor for string with that id into buf (buflen >= 256) */ | |
856 | int usb_gadget_get_string (struct usb_gadget_strings *table, int id, u8 *buf); | |
857 | ||
858 | /*-------------------------------------------------------------------------*/ | |
859 | ||
860 | /* utility to simplify managing config descriptors */ | |
861 | ||
862 | /* write vector of descriptors into buffer */ | |
863 | int usb_descriptor_fillbuf(void *, unsigned, | |
864 | const struct usb_descriptor_header **); | |
865 | ||
866 | /* build config descriptor from single descriptor vector */ | |
867 | int usb_gadget_config_buf(const struct usb_config_descriptor *config, | |
868 | void *buf, unsigned buflen, const struct usb_descriptor_header **desc); | |
869 | ||
870 | /*-------------------------------------------------------------------------*/ | |
871 | ||
872 | /* utility wrapping a simple endpoint selection policy */ | |
873 | ||
874 | extern struct usb_ep *usb_ep_autoconfig (struct usb_gadget *, | |
875 | struct usb_endpoint_descriptor *) __init; | |
876 | ||
877 | extern void usb_ep_autoconfig_reset (struct usb_gadget *) __init; | |
878 | ||
879 | #endif /* __KERNEL__ */ | |
880 | ||
881 | #endif /* __LINUX_USB_GADGET_H */ |