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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 | ||
1da177e4 LT |
237 | /** |
238 | * usb_ep_queue - queues (submits) an I/O request to an endpoint. | |
239 | * @ep:the endpoint associated with the request | |
240 | * @req:the request being submitted | |
241 | * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't | |
242 | * pre-allocate all necessary memory with the request. | |
243 | * | |
244 | * This tells the device controller to perform the specified request through | |
245 | * that endpoint (reading or writing a buffer). When the request completes, | |
246 | * including being canceled by usb_ep_dequeue(), the request's completion | |
247 | * routine is called to return the request to the driver. Any endpoint | |
248 | * (except control endpoints like ep0) may have more than one transfer | |
249 | * request queued; they complete in FIFO order. Once a gadget driver | |
250 | * submits a request, that request may not be examined or modified until it | |
251 | * is given back to that driver through the completion callback. | |
252 | * | |
253 | * Each request is turned into one or more packets. The controller driver | |
254 | * never merges adjacent requests into the same packet. OUT transfers | |
255 | * will sometimes use data that's already buffered in the hardware. | |
256 | * Drivers can rely on the fact that the first byte of the request's buffer | |
257 | * always corresponds to the first byte of some USB packet, for both | |
258 | * IN and OUT transfers. | |
259 | * | |
260 | * Bulk endpoints can queue any amount of data; the transfer is packetized | |
261 | * automatically. The last packet will be short if the request doesn't fill it | |
262 | * out completely. Zero length packets (ZLPs) should be avoided in portable | |
263 | * protocols since not all usb hardware can successfully handle zero length | |
264 | * packets. (ZLPs may be explicitly written, and may be implicitly written if | |
265 | * the request 'zero' flag is set.) Bulk endpoints may also be used | |
266 | * for interrupt transfers; but the reverse is not true, and some endpoints | |
267 | * won't support every interrupt transfer. (Such as 768 byte packets.) | |
268 | * | |
269 | * Interrupt-only endpoints are less functional than bulk endpoints, for | |
270 | * example by not supporting queueing or not handling buffers that are | |
271 | * larger than the endpoint's maxpacket size. They may also treat data | |
272 | * toggle differently. | |
273 | * | |
274 | * Control endpoints ... after getting a setup() callback, the driver queues | |
275 | * one response (even if it would be zero length). That enables the | |
276 | * status ack, after transfering data as specified in the response. Setup | |
277 | * functions may return negative error codes to generate protocol stalls. | |
278 | * (Note that some USB device controllers disallow protocol stall responses | |
279 | * in some cases.) When control responses are deferred (the response is | |
280 | * written after the setup callback returns), then usb_ep_set_halt() may be | |
281 | * used on ep0 to trigger protocol stalls. | |
282 | * | |
283 | * For periodic endpoints, like interrupt or isochronous ones, the usb host | |
284 | * arranges to poll once per interval, and the gadget driver usually will | |
285 | * have queued some data to transfer at that time. | |
286 | * | |
287 | * Returns zero, or a negative error code. Endpoints that are not enabled | |
288 | * report errors; errors will also be | |
289 | * reported when the usb peripheral is disconnected. | |
290 | */ | |
291 | static inline int | |
55016f10 | 292 | usb_ep_queue (struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags) |
1da177e4 LT |
293 | { |
294 | return ep->ops->queue (ep, req, gfp_flags); | |
295 | } | |
296 | ||
297 | /** | |
298 | * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint | |
299 | * @ep:the endpoint associated with the request | |
300 | * @req:the request being canceled | |
301 | * | |
302 | * if the request is still active on the endpoint, it is dequeued and its | |
303 | * completion routine is called (with status -ECONNRESET); else a negative | |
304 | * error code is returned. | |
305 | * | |
306 | * note that some hardware can't clear out write fifos (to unlink the request | |
307 | * at the head of the queue) except as part of disconnecting from usb. such | |
308 | * restrictions prevent drivers from supporting configuration changes, | |
309 | * even to configuration zero (a "chapter 9" requirement). | |
310 | */ | |
311 | static inline int usb_ep_dequeue (struct usb_ep *ep, struct usb_request *req) | |
312 | { | |
313 | return ep->ops->dequeue (ep, req); | |
314 | } | |
315 | ||
316 | /** | |
317 | * usb_ep_set_halt - sets the endpoint halt feature. | |
318 | * @ep: the non-isochronous endpoint being stalled | |
319 | * | |
320 | * Use this to stall an endpoint, perhaps as an error report. | |
321 | * Except for control endpoints, | |
322 | * the endpoint stays halted (will not stream any data) until the host | |
323 | * clears this feature; drivers may need to empty the endpoint's request | |
324 | * queue first, to make sure no inappropriate transfers happen. | |
325 | * | |
326 | * Note that while an endpoint CLEAR_FEATURE will be invisible to the | |
327 | * gadget driver, a SET_INTERFACE will not be. To reset endpoints for the | |
328 | * current altsetting, see usb_ep_clear_halt(). When switching altsettings, | |
329 | * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints. | |
330 | * | |
331 | * Returns zero, or a negative error code. On success, this call sets | |
332 | * underlying hardware state that blocks data transfers. | |
333 | * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any | |
334 | * transfer requests are still queued, or if the controller hardware | |
335 | * (usually a FIFO) still holds bytes that the host hasn't collected. | |
336 | */ | |
337 | static inline int | |
338 | usb_ep_set_halt (struct usb_ep *ep) | |
339 | { | |
340 | return ep->ops->set_halt (ep, 1); | |
341 | } | |
342 | ||
343 | /** | |
344 | * usb_ep_clear_halt - clears endpoint halt, and resets toggle | |
345 | * @ep:the bulk or interrupt endpoint being reset | |
346 | * | |
347 | * Use this when responding to the standard usb "set interface" request, | |
348 | * for endpoints that aren't reconfigured, after clearing any other state | |
349 | * in the endpoint's i/o queue. | |
350 | * | |
351 | * Returns zero, or a negative error code. On success, this call clears | |
352 | * the underlying hardware state reflecting endpoint halt and data toggle. | |
353 | * Note that some hardware can't support this request (like pxa2xx_udc), | |
354 | * and accordingly can't correctly implement interface altsettings. | |
355 | */ | |
356 | static inline int | |
357 | usb_ep_clear_halt (struct usb_ep *ep) | |
358 | { | |
359 | return ep->ops->set_halt (ep, 0); | |
360 | } | |
361 | ||
362 | /** | |
363 | * usb_ep_fifo_status - returns number of bytes in fifo, or error | |
364 | * @ep: the endpoint whose fifo status is being checked. | |
365 | * | |
366 | * FIFO endpoints may have "unclaimed data" in them in certain cases, | |
367 | * such as after aborted transfers. Hosts may not have collected all | |
368 | * the IN data written by the gadget driver (and reported by a request | |
369 | * completion). The gadget driver may not have collected all the data | |
370 | * written OUT to it by the host. Drivers that need precise handling for | |
371 | * fault reporting or recovery may need to use this call. | |
372 | * | |
373 | * This returns the number of such bytes in the fifo, or a negative | |
374 | * errno if the endpoint doesn't use a FIFO or doesn't support such | |
375 | * precise handling. | |
376 | */ | |
377 | static inline int | |
378 | usb_ep_fifo_status (struct usb_ep *ep) | |
379 | { | |
380 | if (ep->ops->fifo_status) | |
381 | return ep->ops->fifo_status (ep); | |
382 | else | |
383 | return -EOPNOTSUPP; | |
384 | } | |
385 | ||
386 | /** | |
387 | * usb_ep_fifo_flush - flushes contents of a fifo | |
388 | * @ep: the endpoint whose fifo is being flushed. | |
389 | * | |
390 | * This call may be used to flush the "unclaimed data" that may exist in | |
391 | * an endpoint fifo after abnormal transaction terminations. The call | |
392 | * must never be used except when endpoint is not being used for any | |
393 | * protocol translation. | |
394 | */ | |
395 | static inline void | |
396 | usb_ep_fifo_flush (struct usb_ep *ep) | |
397 | { | |
398 | if (ep->ops->fifo_flush) | |
399 | ep->ops->fifo_flush (ep); | |
400 | } | |
401 | ||
402 | ||
403 | /*-------------------------------------------------------------------------*/ | |
404 | ||
405 | struct usb_gadget; | |
406 | ||
407 | /* the rest of the api to the controller hardware: device operations, | |
408 | * which don't involve endpoints (or i/o). | |
409 | */ | |
410 | struct usb_gadget_ops { | |
411 | int (*get_frame)(struct usb_gadget *); | |
412 | int (*wakeup)(struct usb_gadget *); | |
413 | int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered); | |
414 | int (*vbus_session) (struct usb_gadget *, int is_active); | |
415 | int (*vbus_draw) (struct usb_gadget *, unsigned mA); | |
416 | int (*pullup) (struct usb_gadget *, int is_on); | |
417 | int (*ioctl)(struct usb_gadget *, | |
418 | unsigned code, unsigned long param); | |
419 | }; | |
420 | ||
421 | /** | |
422 | * struct usb_gadget - represents a usb slave device | |
423 | * @ops: Function pointers used to access hardware-specific operations. | |
424 | * @ep0: Endpoint zero, used when reading or writing responses to | |
425 | * driver setup() requests | |
426 | * @ep_list: List of other endpoints supported by the device. | |
427 | * @speed: Speed of current connection to USB host. | |
428 | * @is_dualspeed: True if the controller supports both high and full speed | |
429 | * operation. If it does, the gadget driver must also support both. | |
430 | * @is_otg: True if the USB device port uses a Mini-AB jack, so that the | |
431 | * gadget driver must provide a USB OTG descriptor. | |
432 | * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable | |
433 | * is in the Mini-AB jack, and HNP has been used to switch roles | |
434 | * so that the "A" device currently acts as A-Peripheral, not A-Host. | |
435 | * @a_hnp_support: OTG device feature flag, indicating that the A-Host | |
436 | * supports HNP at this port. | |
437 | * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host | |
438 | * only supports HNP on a different root port. | |
439 | * @b_hnp_enable: OTG device feature flag, indicating that the A-Host | |
440 | * enabled HNP support. | |
441 | * @name: Identifies the controller hardware type. Used in diagnostics | |
442 | * and sometimes configuration. | |
443 | * @dev: Driver model state for this abstract device. | |
444 | * | |
445 | * Gadgets have a mostly-portable "gadget driver" implementing device | |
446 | * functions, handling all usb configurations and interfaces. Gadget | |
447 | * drivers talk to hardware-specific code indirectly, through ops vectors. | |
448 | * That insulates the gadget driver from hardware details, and packages | |
449 | * the hardware endpoints through generic i/o queues. The "usb_gadget" | |
450 | * and "usb_ep" interfaces provide that insulation from the hardware. | |
451 | * | |
452 | * Except for the driver data, all fields in this structure are | |
453 | * read-only to the gadget driver. That driver data is part of the | |
454 | * "driver model" infrastructure in 2.6 (and later) kernels, and for | |
455 | * earlier systems is grouped in a similar structure that's not known | |
456 | * to the rest of the kernel. | |
457 | * | |
458 | * Values of the three OTG device feature flags are updated before the | |
459 | * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before | |
460 | * driver suspend() calls. They are valid only when is_otg, and when the | |
461 | * device is acting as a B-Peripheral (so is_a_peripheral is false). | |
462 | */ | |
463 | struct usb_gadget { | |
464 | /* readonly to gadget driver */ | |
465 | const struct usb_gadget_ops *ops; | |
466 | struct usb_ep *ep0; | |
467 | struct list_head ep_list; /* of usb_ep */ | |
468 | enum usb_device_speed speed; | |
469 | unsigned is_dualspeed:1; | |
470 | unsigned is_otg:1; | |
471 | unsigned is_a_peripheral:1; | |
472 | unsigned b_hnp_enable:1; | |
473 | unsigned a_hnp_support:1; | |
474 | unsigned a_alt_hnp_support:1; | |
475 | const char *name; | |
476 | struct device dev; | |
477 | }; | |
478 | ||
479 | static inline void set_gadget_data (struct usb_gadget *gadget, void *data) | |
480 | { dev_set_drvdata (&gadget->dev, data); } | |
481 | static inline void *get_gadget_data (struct usb_gadget *gadget) | |
482 | { return dev_get_drvdata (&gadget->dev); } | |
483 | ||
484 | /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */ | |
485 | #define gadget_for_each_ep(tmp,gadget) \ | |
486 | list_for_each_entry(tmp, &(gadget)->ep_list, ep_list) | |
487 | ||
488 | ||
489 | /** | |
490 | * usb_gadget_frame_number - returns the current frame number | |
491 | * @gadget: controller that reports the frame number | |
492 | * | |
493 | * Returns the usb frame number, normally eleven bits from a SOF packet, | |
494 | * or negative errno if this device doesn't support this capability. | |
495 | */ | |
496 | static inline int usb_gadget_frame_number (struct usb_gadget *gadget) | |
497 | { | |
498 | return gadget->ops->get_frame (gadget); | |
499 | } | |
500 | ||
501 | /** | |
502 | * usb_gadget_wakeup - tries to wake up the host connected to this gadget | |
503 | * @gadget: controller used to wake up the host | |
504 | * | |
505 | * Returns zero on success, else negative error code if the hardware | |
506 | * doesn't support such attempts, or its support has not been enabled | |
507 | * by the usb host. Drivers must return device descriptors that report | |
508 | * their ability to support this, or hosts won't enable it. | |
509 | * | |
510 | * This may also try to use SRP to wake the host and start enumeration, | |
511 | * even if OTG isn't otherwise in use. OTG devices may also start | |
512 | * remote wakeup even when hosts don't explicitly enable it. | |
513 | */ | |
514 | static inline int usb_gadget_wakeup (struct usb_gadget *gadget) | |
515 | { | |
516 | if (!gadget->ops->wakeup) | |
517 | return -EOPNOTSUPP; | |
518 | return gadget->ops->wakeup (gadget); | |
519 | } | |
520 | ||
521 | /** | |
522 | * usb_gadget_set_selfpowered - sets the device selfpowered feature. | |
523 | * @gadget:the device being declared as self-powered | |
524 | * | |
525 | * this affects the device status reported by the hardware driver | |
526 | * to reflect that it now has a local power supply. | |
527 | * | |
528 | * returns zero on success, else negative errno. | |
529 | */ | |
530 | static inline int | |
531 | usb_gadget_set_selfpowered (struct usb_gadget *gadget) | |
532 | { | |
533 | if (!gadget->ops->set_selfpowered) | |
534 | return -EOPNOTSUPP; | |
535 | return gadget->ops->set_selfpowered (gadget, 1); | |
536 | } | |
537 | ||
538 | /** | |
539 | * usb_gadget_clear_selfpowered - clear the device selfpowered feature. | |
540 | * @gadget:the device being declared as bus-powered | |
541 | * | |
542 | * this affects the device status reported by the hardware driver. | |
543 | * some hardware may not support bus-powered operation, in which | |
544 | * case this feature's value can never change. | |
545 | * | |
546 | * returns zero on success, else negative errno. | |
547 | */ | |
548 | static inline int | |
549 | usb_gadget_clear_selfpowered (struct usb_gadget *gadget) | |
550 | { | |
551 | if (!gadget->ops->set_selfpowered) | |
552 | return -EOPNOTSUPP; | |
553 | return gadget->ops->set_selfpowered (gadget, 0); | |
554 | } | |
555 | ||
556 | /** | |
557 | * usb_gadget_vbus_connect - Notify controller that VBUS is powered | |
558 | * @gadget:The device which now has VBUS power. | |
559 | * | |
560 | * This call is used by a driver for an external transceiver (or GPIO) | |
561 | * that detects a VBUS power session starting. Common responses include | |
562 | * resuming the controller, activating the D+ (or D-) pullup to let the | |
563 | * host detect that a USB device is attached, and starting to draw power | |
564 | * (8mA or possibly more, especially after SET_CONFIGURATION). | |
565 | * | |
566 | * Returns zero on success, else negative errno. | |
567 | */ | |
568 | static inline int | |
569 | usb_gadget_vbus_connect(struct usb_gadget *gadget) | |
570 | { | |
571 | if (!gadget->ops->vbus_session) | |
572 | return -EOPNOTSUPP; | |
573 | return gadget->ops->vbus_session (gadget, 1); | |
574 | } | |
575 | ||
576 | /** | |
577 | * usb_gadget_vbus_draw - constrain controller's VBUS power usage | |
578 | * @gadget:The device whose VBUS usage is being described | |
579 | * @mA:How much current to draw, in milliAmperes. This should be twice | |
580 | * the value listed in the configuration descriptor bMaxPower field. | |
581 | * | |
582 | * This call is used by gadget drivers during SET_CONFIGURATION calls, | |
583 | * reporting how much power the device may consume. For example, this | |
584 | * could affect how quickly batteries are recharged. | |
585 | * | |
586 | * Returns zero on success, else negative errno. | |
587 | */ | |
588 | static inline int | |
589 | usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA) | |
590 | { | |
591 | if (!gadget->ops->vbus_draw) | |
592 | return -EOPNOTSUPP; | |
593 | return gadget->ops->vbus_draw (gadget, mA); | |
594 | } | |
595 | ||
596 | /** | |
597 | * usb_gadget_vbus_disconnect - notify controller about VBUS session end | |
598 | * @gadget:the device whose VBUS supply is being described | |
599 | * | |
600 | * This call is used by a driver for an external transceiver (or GPIO) | |
601 | * that detects a VBUS power session ending. Common responses include | |
602 | * reversing everything done in usb_gadget_vbus_connect(). | |
603 | * | |
604 | * Returns zero on success, else negative errno. | |
605 | */ | |
606 | static inline int | |
607 | usb_gadget_vbus_disconnect(struct usb_gadget *gadget) | |
608 | { | |
609 | if (!gadget->ops->vbus_session) | |
610 | return -EOPNOTSUPP; | |
611 | return gadget->ops->vbus_session (gadget, 0); | |
612 | } | |
613 | ||
614 | /** | |
615 | * usb_gadget_connect - software-controlled connect to USB host | |
616 | * @gadget:the peripheral being connected | |
617 | * | |
618 | * Enables the D+ (or potentially D-) pullup. The host will start | |
619 | * enumerating this gadget when the pullup is active and a VBUS session | |
620 | * is active (the link is powered). This pullup is always enabled unless | |
621 | * usb_gadget_disconnect() has been used to disable it. | |
622 | * | |
623 | * Returns zero on success, else negative errno. | |
624 | */ | |
625 | static inline int | |
626 | usb_gadget_connect (struct usb_gadget *gadget) | |
627 | { | |
628 | if (!gadget->ops->pullup) | |
629 | return -EOPNOTSUPP; | |
630 | return gadget->ops->pullup (gadget, 1); | |
631 | } | |
632 | ||
633 | /** | |
634 | * usb_gadget_disconnect - software-controlled disconnect from USB host | |
635 | * @gadget:the peripheral being disconnected | |
636 | * | |
637 | * Disables the D+ (or potentially D-) pullup, which the host may see | |
638 | * as a disconnect (when a VBUS session is active). Not all systems | |
639 | * support software pullup controls. | |
640 | * | |
641 | * This routine may be used during the gadget driver bind() call to prevent | |
642 | * the peripheral from ever being visible to the USB host, unless later | |
643 | * usb_gadget_connect() is called. For example, user mode components may | |
644 | * need to be activated before the system can talk to hosts. | |
645 | * | |
646 | * Returns zero on success, else negative errno. | |
647 | */ | |
648 | static inline int | |
649 | usb_gadget_disconnect (struct usb_gadget *gadget) | |
650 | { | |
651 | if (!gadget->ops->pullup) | |
652 | return -EOPNOTSUPP; | |
653 | return gadget->ops->pullup (gadget, 0); | |
654 | } | |
655 | ||
656 | ||
657 | ||
658 | /*-------------------------------------------------------------------------*/ | |
659 | ||
660 | /** | |
661 | * struct usb_gadget_driver - driver for usb 'slave' devices | |
662 | * @function: String describing the gadget's function | |
663 | * @speed: Highest speed the driver handles. | |
664 | * @bind: Invoked when the driver is bound to a gadget, usually | |
665 | * after registering the driver. | |
666 | * At that point, ep0 is fully initialized, and ep_list holds | |
667 | * the currently-available endpoints. | |
668 | * Called in a context that permits sleeping. | |
669 | * @setup: Invoked for ep0 control requests that aren't handled by | |
670 | * the hardware level driver. Most calls must be handled by | |
671 | * the gadget driver, including descriptor and configuration | |
672 | * management. The 16 bit members of the setup data are in | |
1bbc1696 | 673 | * USB byte order. Called in_interrupt; this may not sleep. Driver |
1da177e4 LT |
674 | * queues a response to ep0, or returns negative to stall. |
675 | * @disconnect: Invoked after all transfers have been stopped, | |
676 | * when the host is disconnected. May be called in_interrupt; this | |
677 | * may not sleep. Some devices can't detect disconnect, so this might | |
678 | * not be called except as part of controller shutdown. | |
679 | * @unbind: Invoked when the driver is unbound from a gadget, | |
680 | * usually from rmmod (after a disconnect is reported). | |
681 | * Called in a context that permits sleeping. | |
682 | * @suspend: Invoked on USB suspend. May be called in_interrupt. | |
683 | * @resume: Invoked on USB resume. May be called in_interrupt. | |
684 | * @driver: Driver model state for this driver. | |
685 | * | |
686 | * Devices are disabled till a gadget driver successfully bind()s, which | |
687 | * means the driver will handle setup() requests needed to enumerate (and | |
688 | * meet "chapter 9" requirements) then do some useful work. | |
689 | * | |
690 | * If gadget->is_otg is true, the gadget driver must provide an OTG | |
691 | * descriptor during enumeration, or else fail the bind() call. In such | |
692 | * cases, no USB traffic may flow until both bind() returns without | |
693 | * having called usb_gadget_disconnect(), and the USB host stack has | |
694 | * initialized. | |
695 | * | |
696 | * Drivers use hardware-specific knowledge to configure the usb hardware. | |
697 | * endpoint addressing is only one of several hardware characteristics that | |
698 | * are in descriptors the ep0 implementation returns from setup() calls. | |
699 | * | |
700 | * Except for ep0 implementation, most driver code shouldn't need change to | |
701 | * run on top of different usb controllers. It'll use endpoints set up by | |
702 | * that ep0 implementation. | |
703 | * | |
704 | * The usb controller driver handles a few standard usb requests. Those | |
705 | * include set_address, and feature flags for devices, interfaces, and | |
706 | * endpoints (the get_status, set_feature, and clear_feature requests). | |
707 | * | |
708 | * Accordingly, the driver's setup() callback must always implement all | |
709 | * get_descriptor requests, returning at least a device descriptor and | |
710 | * a configuration descriptor. Drivers must make sure the endpoint | |
711 | * descriptors match any hardware constraints. Some hardware also constrains | |
712 | * other descriptors. (The pxa250 allows only configurations 1, 2, or 3). | |
713 | * | |
714 | * The driver's setup() callback must also implement set_configuration, | |
715 | * and should also implement set_interface, get_configuration, and | |
716 | * get_interface. Setting a configuration (or interface) is where | |
717 | * endpoints should be activated or (config 0) shut down. | |
718 | * | |
719 | * (Note that only the default control endpoint is supported. Neither | |
720 | * hosts nor devices generally support control traffic except to ep0.) | |
721 | * | |
722 | * Most devices will ignore USB suspend/resume operations, and so will | |
723 | * not provide those callbacks. However, some may need to change modes | |
724 | * when the host is not longer directing those activities. For example, | |
725 | * local controls (buttons, dials, etc) may need to be re-enabled since | |
726 | * the (remote) host can't do that any longer; or an error state might | |
727 | * be cleared, to make the device behave identically whether or not | |
728 | * power is maintained. | |
729 | */ | |
730 | struct usb_gadget_driver { | |
731 | char *function; | |
732 | enum usb_device_speed speed; | |
733 | int (*bind)(struct usb_gadget *); | |
734 | void (*unbind)(struct usb_gadget *); | |
735 | int (*setup)(struct usb_gadget *, | |
736 | const struct usb_ctrlrequest *); | |
737 | void (*disconnect)(struct usb_gadget *); | |
738 | void (*suspend)(struct usb_gadget *); | |
739 | void (*resume)(struct usb_gadget *); | |
740 | ||
741 | // FIXME support safe rmmod | |
742 | struct device_driver driver; | |
743 | }; | |
744 | ||
745 | ||
746 | ||
747 | /*-------------------------------------------------------------------------*/ | |
748 | ||
749 | /* driver modules register and unregister, as usual. | |
750 | * these calls must be made in a context that can sleep. | |
751 | * | |
752 | * these will usually be implemented directly by the hardware-dependent | |
753 | * usb bus interface driver, which will only support a single driver. | |
754 | */ | |
755 | ||
756 | /** | |
757 | * usb_gadget_register_driver - register a gadget driver | |
758 | * @driver:the driver being registered | |
759 | * | |
760 | * Call this in your gadget driver's module initialization function, | |
761 | * to tell the underlying usb controller driver about your driver. | |
762 | * The driver's bind() function will be called to bind it to a | |
329af28b DB |
763 | * gadget before this registration call returns. It's expected that |
764 | * the bind() functions will be in init sections. | |
765 | * This function must be called in a context that can sleep. | |
1da177e4 LT |
766 | */ |
767 | int usb_gadget_register_driver (struct usb_gadget_driver *driver); | |
768 | ||
769 | /** | |
770 | * usb_gadget_unregister_driver - unregister a gadget driver | |
771 | * @driver:the driver being unregistered | |
772 | * | |
773 | * Call this in your gadget driver's module cleanup function, | |
774 | * to tell the underlying usb controller that your driver is | |
775 | * going away. If the controller is connected to a USB host, | |
776 | * it will first disconnect(). The driver is also requested | |
777 | * to unbind() and clean up any device state, before this procedure | |
329af28b DB |
778 | * finally returns. It's expected that the unbind() functions |
779 | * will in in exit sections, so may not be linked in some kernels. | |
1da177e4 LT |
780 | * This function must be called in a context that can sleep. |
781 | */ | |
782 | int usb_gadget_unregister_driver (struct usb_gadget_driver *driver); | |
783 | ||
784 | /*-------------------------------------------------------------------------*/ | |
785 | ||
786 | /* utility to simplify dealing with string descriptors */ | |
787 | ||
788 | /** | |
789 | * struct usb_string - wraps a C string and its USB id | |
790 | * @id:the (nonzero) ID for this string | |
791 | * @s:the string, in UTF-8 encoding | |
792 | * | |
793 | * If you're using usb_gadget_get_string(), use this to wrap a string | |
794 | * together with its ID. | |
795 | */ | |
796 | struct usb_string { | |
797 | u8 id; | |
798 | const char *s; | |
799 | }; | |
800 | ||
801 | /** | |
802 | * struct usb_gadget_strings - a set of USB strings in a given language | |
803 | * @language:identifies the strings' language (0x0409 for en-us) | |
804 | * @strings:array of strings with their ids | |
805 | * | |
806 | * If you're using usb_gadget_get_string(), use this to wrap all the | |
807 | * strings for a given language. | |
808 | */ | |
809 | struct usb_gadget_strings { | |
810 | u16 language; /* 0x0409 for en-us */ | |
811 | struct usb_string *strings; | |
812 | }; | |
813 | ||
814 | /* put descriptor for string with that id into buf (buflen >= 256) */ | |
815 | int usb_gadget_get_string (struct usb_gadget_strings *table, int id, u8 *buf); | |
816 | ||
817 | /*-------------------------------------------------------------------------*/ | |
818 | ||
819 | /* utility to simplify managing config descriptors */ | |
820 | ||
821 | /* write vector of descriptors into buffer */ | |
822 | int usb_descriptor_fillbuf(void *, unsigned, | |
823 | const struct usb_descriptor_header **); | |
824 | ||
825 | /* build config descriptor from single descriptor vector */ | |
826 | int usb_gadget_config_buf(const struct usb_config_descriptor *config, | |
827 | void *buf, unsigned buflen, const struct usb_descriptor_header **desc); | |
828 | ||
829 | /*-------------------------------------------------------------------------*/ | |
830 | ||
831 | /* utility wrapping a simple endpoint selection policy */ | |
832 | ||
833 | extern struct usb_ep *usb_ep_autoconfig (struct usb_gadget *, | |
a353678d | 834 | struct usb_endpoint_descriptor *) __devinit; |
1da177e4 | 835 | |
a353678d | 836 | extern void usb_ep_autoconfig_reset (struct usb_gadget *) __devinit; |
1da177e4 LT |
837 | |
838 | #endif /* __KERNEL__ */ | |
839 | ||
840 | #endif /* __LINUX_USB_GADGET_H */ |