1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * <linux/usb/gadget.h>
4 *
5 * We call the USB code inside a Linux-based peripheral device a "gadget"
6 * driver, except for the hardware-specific bus glue. One USB host can
7 * master many USB gadgets, but the gadgets are only slaved to one host.
8 *
9 *
10 * (C) Copyright 2002-2004 by David Brownell
11 * All Rights Reserved.
12 *
13 * This software is licensed under the GNU GPL version 2.
14 */
15
16 #ifndef __LINUX_USB_GADGET_H
17 #define __LINUX_USB_GADGET_H
18
19 #include <linux/device.h>
20 #include <linux/errno.h>
21 #include <linux/init.h>
22 #include <linux/list.h>
23 #include <linux/slab.h>
24 #include <linux/scatterlist.h>
25 #include <linux/types.h>
26 #include <linux/workqueue.h>
27 #include <linux/usb/ch9.h>
28
29 #define UDC_TRACE_STR_MAX 512
30
31 struct usb_ep;
32
33 /**
34 * struct usb_request - describes one i/o request
35 * @buf: Buffer used for data. Always provide this; some controllers
36 * only use PIO, or don't use DMA for some endpoints.
37 * @dma: DMA address corresponding to 'buf'. If you don't set this
38 * field, and the usb controller needs one, it is responsible
39 * for mapping and unmapping the buffer.
40 * @sg: a scatterlist for SG-capable controllers.
41 * @num_sgs: number of SG entries
42 * @num_mapped_sgs: number of SG entries mapped to DMA (internal)
43 * @length: Length of that data
44 * @stream_id: The stream id, when USB3.0 bulk streams are being used
45 * @no_interrupt: If true, hints that no completion irq is needed.
46 * Helpful sometimes with deep request queues that are handled
47 * directly by DMA controllers.
48 * @zero: If true, when writing data, makes the last packet be "short"
49 * by adding a zero length packet as needed;
50 * @short_not_ok: When reading data, makes short packets be
51 * treated as errors (queue stops advancing till cleanup).
52 * @dma_mapped: Indicates if request has been mapped to DMA (internal)
53 * @complete: Function called when request completes, so this request and
54 * its buffer may be re-used. The function will always be called with
55 * interrupts disabled, and it must not sleep.
56 * Reads terminate with a short packet, or when the buffer fills,
57 * whichever comes first. When writes terminate, some data bytes
58 * will usually still be in flight (often in a hardware fifo).
59 * Errors (for reads or writes) stop the queue from advancing
60 * until the completion function returns, so that any transfers
61 * invalidated by the error may first be dequeued.
62 * @context: For use by the completion callback
63 * @list: For use by the gadget driver.
64 * @frame_number: Reports the interval number in (micro)frame in which the
65 * isochronous transfer was transmitted or received.
66 * @status: Reports completion code, zero or a negative errno.
67 * Normally, faults block the transfer queue from advancing until
68 * the completion callback returns.
69 * Code "-ESHUTDOWN" indicates completion caused by device disconnect,
70 * or when the driver disabled the endpoint.
71 * @actual: Reports bytes transferred to/from the buffer. For reads (OUT
72 * transfers) this may be less than the requested length. If the
73 * short_not_ok flag is set, short reads are treated as errors
74 * even when status otherwise indicates successful completion.
75 * Note that for writes (IN transfers) some data bytes may still
76 * reside in a device-side FIFO when the request is reported as
77 * complete.
78 *
79 * These are allocated/freed through the endpoint they're used with. The
80 * hardware's driver can add extra per-request data to the memory it returns,
81 * which often avoids separate memory allocations (potential failures),
82 * later when the request is queued.
83 *
84 * Request flags affect request handling, such as whether a zero length
85 * packet is written (the "zero" flag), whether a short read should be
86 * treated as an error (blocking request queue advance, the "short_not_ok"
87 * flag), or hinting that an interrupt is not required (the "no_interrupt"
88 * flag, for use with deep request queues).
89 *
90 * Bulk endpoints can use any size buffers, and can also be used for interrupt
91 * transfers. interrupt-only endpoints can be much less functional.
92 *
93 * NOTE: this is analogous to 'struct urb' on the host side, except that
94 * it's thinner and promotes more pre-allocation.
95 */
96
97 struct usb_request {
98 void *buf;
99 unsigned length;
100 dma_addr_t dma;
101
102 struct scatterlist *sg;
103 unsigned num_sgs;
104 unsigned num_mapped_sgs;
105
106 unsigned stream_id:16;
107 unsigned no_interrupt:1;
108 unsigned zero:1;
109 unsigned short_not_ok:1;
110 unsigned dma_mapped:1;
111
112 void (*complete)(struct usb_ep *ep,
113 struct usb_request *req);
114 void *context;
115 struct list_head list;
116
117 unsigned frame_number; /* ISO ONLY */
118
119 int status;
120 unsigned actual;
121 };
122
123 /*-------------------------------------------------------------------------*/
124
125 /* endpoint-specific parts of the api to the usb controller hardware.
126 * unlike the urb model, (de)multiplexing layers are not required.
127 * (so this api could slash overhead if used on the host side...)
128 *
129 * note that device side usb controllers commonly differ in how many
130 * endpoints they support, as well as their capabilities.
131 */
132 struct usb_ep_ops {
133 int (*enable) (struct usb_ep *ep,
134 const struct usb_endpoint_descriptor *desc);
135 int (*disable) (struct usb_ep *ep);
136 void (*dispose) (struct usb_ep *ep);
137
138 struct usb_request *(*alloc_request) (struct usb_ep *ep,
139 gfp_t gfp_flags);
140 void (*free_request) (struct usb_ep *ep, struct usb_request *req);
141
142 int (*queue) (struct usb_ep *ep, struct usb_request *req,
143 gfp_t gfp_flags);
144 int (*dequeue) (struct usb_ep *ep, struct usb_request *req);
145
146 int (*set_halt) (struct usb_ep *ep, int value);
147 int (*set_wedge) (struct usb_ep *ep);
148
149 int (*fifo_status) (struct usb_ep *ep);
150 void (*fifo_flush) (struct usb_ep *ep);
151 };
152
153 /**
154 * struct usb_ep_caps - endpoint capabilities description
155 * @type_control:Endpoint supports control type (reserved for ep0).
156 * @type_iso:Endpoint supports isochronous transfers.
157 * @type_bulk:Endpoint supports bulk transfers.
158 * @type_int:Endpoint supports interrupt transfers.
159 * @dir_in:Endpoint supports IN direction.
160 * @dir_out:Endpoint supports OUT direction.
161 */
162 struct usb_ep_caps {
163 unsigned type_control:1;
164 unsigned type_iso:1;
165 unsigned type_bulk:1;
166 unsigned type_int:1;
167 unsigned dir_in:1;
168 unsigned dir_out:1;
169 };
170
171 #define USB_EP_CAPS_TYPE_CONTROL 0x01
172 #define USB_EP_CAPS_TYPE_ISO 0x02
173 #define USB_EP_CAPS_TYPE_BULK 0x04
174 #define USB_EP_CAPS_TYPE_INT 0x08
175 #define USB_EP_CAPS_TYPE_ALL \
176 (USB_EP_CAPS_TYPE_ISO | USB_EP_CAPS_TYPE_BULK | USB_EP_CAPS_TYPE_INT)
177 #define USB_EP_CAPS_DIR_IN 0x01
178 #define USB_EP_CAPS_DIR_OUT 0x02
179 #define USB_EP_CAPS_DIR_ALL (USB_EP_CAPS_DIR_IN | USB_EP_CAPS_DIR_OUT)
180
181 #define USB_EP_CAPS(_type, _dir) \
182 { \
183 .type_control = !!(_type & USB_EP_CAPS_TYPE_CONTROL), \
184 .type_iso = !!(_type & USB_EP_CAPS_TYPE_ISO), \
185 .type_bulk = !!(_type & USB_EP_CAPS_TYPE_BULK), \
186 .type_int = !!(_type & USB_EP_CAPS_TYPE_INT), \
187 .dir_in = !!(_dir & USB_EP_CAPS_DIR_IN), \
188 .dir_out = !!(_dir & USB_EP_CAPS_DIR_OUT), \
189 }
190
191 /**
192 * struct usb_ep - device side representation of USB endpoint
193 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk"
194 * @ops: Function pointers used to access hardware-specific operations.
195 * @ep_list:the gadget's ep_list holds all of its endpoints
196 * @caps:The structure describing types and directions supported by endoint.
197 * @enabled: The current endpoint enabled/disabled state.
198 * @claimed: True if this endpoint is claimed by a function.
199 * @maxpacket:The maximum packet size used on this endpoint. The initial
200 * value can sometimes be reduced (hardware allowing), according to
201 * the endpoint descriptor used to configure the endpoint.
202 * @maxpacket_limit:The maximum packet size value which can be handled by this
203 * endpoint. It's set once by UDC driver when endpoint is initialized, and
204 * should not be changed. Should not be confused with maxpacket.
205 * @max_streams: The maximum number of streams supported
206 * by this EP (0 - 16, actual number is 2^n)
207 * @mult: multiplier, 'mult' value for SS Isoc EPs
208 * @maxburst: the maximum number of bursts supported by this EP (for usb3)
209 * @driver_data:for use by the gadget driver.
210 * @address: used to identify the endpoint when finding descriptor that
211 * matches connection speed
212 * @desc: endpoint descriptor. This pointer is set before the endpoint is
213 * enabled and remains valid until the endpoint is disabled.
214 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion
215 * descriptor that is used to configure the endpoint
216 *
217 * the bus controller driver lists all the general purpose endpoints in
218 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list,
219 * and is accessed only in response to a driver setup() callback.
220 */
221
222 struct usb_ep {
223 void *driver_data;
224
225 const char *name;
226 const struct usb_ep_ops *ops;
227 struct list_head ep_list;
228 struct usb_ep_caps caps;
229 bool claimed;
230 bool enabled;
231 unsigned maxpacket:16;
232 unsigned maxpacket_limit:16;
233 unsigned max_streams:16;
234 unsigned mult:2;
235 unsigned maxburst:5;
236 u8 address;
237 const struct usb_endpoint_descriptor *desc;
238 const struct usb_ss_ep_comp_descriptor *comp_desc;
239 };
240
241 /*-------------------------------------------------------------------------*/
242
243 #if IS_ENABLED(CONFIG_USB_GADGET)
244 void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit);
245 int usb_ep_enable(struct usb_ep *ep);
246 int usb_ep_disable(struct usb_ep *ep);
247 struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags);
248 void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req);
249 int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags);
250 int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req);
251 int usb_ep_set_halt(struct usb_ep *ep);
252 int usb_ep_clear_halt(struct usb_ep *ep);
253 int usb_ep_set_wedge(struct usb_ep *ep);
254 int usb_ep_fifo_status(struct usb_ep *ep);
255 void usb_ep_fifo_flush(struct usb_ep *ep);
256 #else
257 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
258 unsigned maxpacket_limit)
259 { }
260 static inline int usb_ep_enable(struct usb_ep *ep)
261 { return 0; }
262 static inline int usb_ep_disable(struct usb_ep *ep)
263 { return 0; }
264 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
265 gfp_t gfp_flags)
266 { return NULL; }
267 static inline void usb_ep_free_request(struct usb_ep *ep,
268 struct usb_request *req)
269 { }
270 static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req,
271 gfp_t gfp_flags)
272 { return 0; }
273 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
274 { return 0; }
275 static inline int usb_ep_set_halt(struct usb_ep *ep)
276 { return 0; }
277 static inline int usb_ep_clear_halt(struct usb_ep *ep)
278 { return 0; }
279 static inline int usb_ep_set_wedge(struct usb_ep *ep)
280 { return 0; }
281 static inline int usb_ep_fifo_status(struct usb_ep *ep)
282 { return 0; }
283 static inline void usb_ep_fifo_flush(struct usb_ep *ep)
284 { }
285 #endif /* USB_GADGET */
286
287 /*-------------------------------------------------------------------------*/
288
289 struct usb_dcd_config_params {
290 __u8 bU1devExitLat; /* U1 Device exit Latency */
291 #define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */
292 __le16 bU2DevExitLat; /* U2 Device exit Latency */
293 #define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */
294 __u8 besl_baseline; /* Recommended baseline BESL (0-15) */
295 __u8 besl_deep; /* Recommended deep BESL (0-15) */
296 #define USB_DEFAULT_BESL_UNSPECIFIED 0xFF /* No recommended value */
297 };
298
299
300 struct usb_gadget;
301 struct usb_gadget_driver;
302 struct usb_udc;
303
304 /* the rest of the api to the controller hardware: device operations,
305 * which don't involve endpoints (or i/o).
306 */
307 struct usb_gadget_ops {
308 int (*get_frame)(struct usb_gadget *);
309 int (*wakeup)(struct usb_gadget *);
310 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
311 int (*vbus_session) (struct usb_gadget *, int is_active);
312 int (*vbus_draw) (struct usb_gadget *, unsigned mA);
313 int (*pullup) (struct usb_gadget *, int is_on);
314 int (*ioctl)(struct usb_gadget *,
315 unsigned code, unsigned long param);
316 void (*get_config_params)(struct usb_gadget *,
317 struct usb_dcd_config_params *);
318 int (*udc_start)(struct usb_gadget *,
319 struct usb_gadget_driver *);
320 int (*udc_stop)(struct usb_gadget *);
321 void (*udc_set_speed)(struct usb_gadget *, enum usb_device_speed);
322 struct usb_ep *(*match_ep)(struct usb_gadget *,
323 struct usb_endpoint_descriptor *,
324 struct usb_ss_ep_comp_descriptor *);
325 };
326
327 /**
328 * struct usb_gadget - represents a usb slave device
329 * @work: (internal use) Workqueue to be used for sysfs_notify()
330 * @udc: struct usb_udc pointer for this gadget
331 * @ops: Function pointers used to access hardware-specific operations.
332 * @ep0: Endpoint zero, used when reading or writing responses to
333 * driver setup() requests
334 * @ep_list: List of other endpoints supported by the device.
335 * @speed: Speed of current connection to USB host.
336 * @max_speed: Maximal speed the UDC can handle. UDC must support this
337 * and all slower speeds.
338 * @state: the state we are now (attached, suspended, configured, etc)
339 * @name: Identifies the controller hardware type. Used in diagnostics
340 * and sometimes configuration.
341 * @dev: Driver model state for this abstract device.
342 * @isoch_delay: value from Set Isoch Delay request. Only valid on SS/SSP
343 * @out_epnum: last used out ep number
344 * @in_epnum: last used in ep number
345 * @mA: last set mA value
346 * @otg_caps: OTG capabilities of this gadget.
347 * @sg_supported: true if we can handle scatter-gather
348 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
349 * gadget driver must provide a USB OTG descriptor.
350 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable
351 * is in the Mini-AB jack, and HNP has been used to switch roles
352 * so that the "A" device currently acts as A-Peripheral, not A-Host.
353 * @a_hnp_support: OTG device feature flag, indicating that the A-Host
354 * supports HNP at this port.
355 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
356 * only supports HNP on a different root port.
357 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
358 * enabled HNP support.
359 * @hnp_polling_support: OTG device feature flag, indicating if the OTG device
360 * in peripheral mode can support HNP polling.
361 * @host_request_flag: OTG device feature flag, indicating if A-Peripheral
362 * or B-Peripheral wants to take host role.
363 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
364 * MaxPacketSize.
365 * @quirk_altset_not_supp: UDC controller doesn't support alt settings.
366 * @quirk_stall_not_supp: UDC controller doesn't support stalling.
367 * @quirk_zlp_not_supp: UDC controller doesn't support ZLP.
368 * @quirk_avoids_skb_reserve: udc/platform wants to avoid skb_reserve() in
369 * u_ether.c to improve performance.
370 * @is_selfpowered: if the gadget is self-powered.
371 * @deactivated: True if gadget is deactivated - in deactivated state it cannot
372 * be connected.
373 * @connected: True if gadget is connected.
374 * @lpm_capable: If the gadget max_speed is FULL or HIGH, this flag
375 * indicates that it supports LPM as per the LPM ECN & errata.
376 *
377 * Gadgets have a mostly-portable "gadget driver" implementing device
378 * functions, handling all usb configurations and interfaces. Gadget
379 * drivers talk to hardware-specific code indirectly, through ops vectors.
380 * That insulates the gadget driver from hardware details, and packages
381 * the hardware endpoints through generic i/o queues. The "usb_gadget"
382 * and "usb_ep" interfaces provide that insulation from the hardware.
383 *
384 * Except for the driver data, all fields in this structure are
385 * read-only to the gadget driver. That driver data is part of the
386 * "driver model" infrastructure in 2.6 (and later) kernels, and for
387 * earlier systems is grouped in a similar structure that's not known
388 * to the rest of the kernel.
389 *
390 * Values of the three OTG device feature flags are updated before the
391 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
392 * driver suspend() calls. They are valid only when is_otg, and when the
393 * device is acting as a B-Peripheral (so is_a_peripheral is false).
394 */
395 struct usb_gadget {
396 struct work_struct work;
397 struct usb_udc *udc;
398 /* readonly to gadget driver */
399 const struct usb_gadget_ops *ops;
400 struct usb_ep *ep0;
401 struct list_head ep_list; /* of usb_ep */
402 enum usb_device_speed speed;
403 enum usb_device_speed max_speed;
404 enum usb_device_state state;
405 const char *name;
406 struct device dev;
407 unsigned isoch_delay;
408 unsigned out_epnum;
409 unsigned in_epnum;
410 unsigned mA;
411 struct usb_otg_caps *otg_caps;
412
413 unsigned sg_supported:1;
414 unsigned is_otg:1;
415 unsigned is_a_peripheral:1;
416 unsigned b_hnp_enable:1;
417 unsigned a_hnp_support:1;
418 unsigned a_alt_hnp_support:1;
419 unsigned hnp_polling_support:1;
420 unsigned host_request_flag:1;
421 unsigned quirk_ep_out_aligned_size:1;
422 unsigned quirk_altset_not_supp:1;
423 unsigned quirk_stall_not_supp:1;
424 unsigned quirk_zlp_not_supp:1;
425 unsigned quirk_avoids_skb_reserve:1;
426 unsigned is_selfpowered:1;
427 unsigned deactivated:1;
428 unsigned connected:1;
429 unsigned lpm_capable:1;
430 };
431 #define work_to_gadget(w) (container_of((w), struct usb_gadget, work))
432
433 static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
434 { dev_set_drvdata(&gadget->dev, data); }
435 static inline void *get_gadget_data(struct usb_gadget *gadget)
436 { return dev_get_drvdata(&gadget->dev); }
437 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
438 {
439 return container_of(dev, struct usb_gadget, dev);
440 }
441
442 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
443 #define gadget_for_each_ep(tmp, gadget) \
444 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
445
446 /**
447 * usb_ep_align - returns @len aligned to ep's maxpacketsize.
448 * @ep: the endpoint whose maxpacketsize is used to align @len
449 * @len: buffer size's length to align to @ep's maxpacketsize
450 *
451 * This helper is used to align buffer's size to an ep's maxpacketsize.
452 */
453 static inline size_t usb_ep_align(struct usb_ep *ep, size_t len)
454 {
455 int max_packet_size = (size_t)usb_endpoint_maxp(ep->desc) & 0x7ff;
456
457 return round_up(len, max_packet_size);
458 }
459
460 /**
461 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget
462 * requires quirk_ep_out_aligned_size, otherwise returns len.
463 * @g: controller to check for quirk
464 * @ep: the endpoint whose maxpacketsize is used to align @len
465 * @len: buffer size's length to align to @ep's maxpacketsize
466 *
467 * This helper is used in case it's required for any reason to check and maybe
468 * align buffer's size to an ep's maxpacketsize.
469 */
470 static inline size_t
471 usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len)
472 {
473 return g->quirk_ep_out_aligned_size ? usb_ep_align(ep, len) : len;
474 }
475
476 /**
477 * gadget_is_altset_supported - return true iff the hardware supports
478 * altsettings
479 * @g: controller to check for quirk
480 */
481 static inline int gadget_is_altset_supported(struct usb_gadget *g)
482 {
483 return !g->quirk_altset_not_supp;
484 }
485
486 /**
487 * gadget_is_stall_supported - return true iff the hardware supports stalling
488 * @g: controller to check for quirk
489 */
490 static inline int gadget_is_stall_supported(struct usb_gadget *g)
491 {
492 return !g->quirk_stall_not_supp;
493 }
494
495 /**
496 * gadget_is_zlp_supported - return true iff the hardware supports zlp
497 * @g: controller to check for quirk
498 */
499 static inline int gadget_is_zlp_supported(struct usb_gadget *g)
500 {
501 return !g->quirk_zlp_not_supp;
502 }
503
504 /**
505 * gadget_avoids_skb_reserve - return true iff the hardware would like to avoid
506 * skb_reserve to improve performance.
507 * @g: controller to check for quirk
508 */
509 static inline int gadget_avoids_skb_reserve(struct usb_gadget *g)
510 {
511 return g->quirk_avoids_skb_reserve;
512 }
513
514 /**
515 * gadget_is_dualspeed - return true iff the hardware handles high speed
516 * @g: controller that might support both high and full speeds
517 */
518 static inline int gadget_is_dualspeed(struct usb_gadget *g)
519 {
520 return g->max_speed >= USB_SPEED_HIGH;
521 }
522
523 /**
524 * gadget_is_superspeed() - return true if the hardware handles superspeed
525 * @g: controller that might support superspeed
526 */
527 static inline int gadget_is_superspeed(struct usb_gadget *g)
528 {
529 return g->max_speed >= USB_SPEED_SUPER;
530 }
531
532 /**
533 * gadget_is_superspeed_plus() - return true if the hardware handles
534 * superspeed plus
535 * @g: controller that might support superspeed plus
536 */
537 static inline int gadget_is_superspeed_plus(struct usb_gadget *g)
538 {
539 return g->max_speed >= USB_SPEED_SUPER_PLUS;
540 }
541
542 /**
543 * gadget_is_otg - return true iff the hardware is OTG-ready
544 * @g: controller that might have a Mini-AB connector
545 *
546 * This is a runtime test, since kernels with a USB-OTG stack sometimes
547 * run on boards which only have a Mini-B (or Mini-A) connector.
548 */
549 static inline int gadget_is_otg(struct usb_gadget *g)
550 {
551 #ifdef CONFIG_USB_OTG
552 return g->is_otg;
553 #else
554 return 0;
555 #endif
556 }
557
558 /*-------------------------------------------------------------------------*/
559
560 #if IS_ENABLED(CONFIG_USB_GADGET)
561 int usb_gadget_frame_number(struct usb_gadget *gadget);
562 int usb_gadget_wakeup(struct usb_gadget *gadget);
563 int usb_gadget_set_selfpowered(struct usb_gadget *gadget);
564 int usb_gadget_clear_selfpowered(struct usb_gadget *gadget);
565 int usb_gadget_vbus_connect(struct usb_gadget *gadget);
566 int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA);
567 int usb_gadget_vbus_disconnect(struct usb_gadget *gadget);
568 int usb_gadget_connect(struct usb_gadget *gadget);
569 int usb_gadget_disconnect(struct usb_gadget *gadget);
570 int usb_gadget_deactivate(struct usb_gadget *gadget);
571 int usb_gadget_activate(struct usb_gadget *gadget);
572 #else
573 static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
574 { return 0; }
575 static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
576 { return 0; }
577 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
578 { return 0; }
579 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
580 { return 0; }
581 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
582 { return 0; }
583 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
584 { return 0; }
585 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
586 { return 0; }
587 static inline int usb_gadget_connect(struct usb_gadget *gadget)
588 { return 0; }
589 static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
590 { return 0; }
591 static inline int usb_gadget_deactivate(struct usb_gadget *gadget)
592 { return 0; }
593 static inline int usb_gadget_activate(struct usb_gadget *gadget)
594 { return 0; }
595 #endif /* CONFIG_USB_GADGET */
596
597 /*-------------------------------------------------------------------------*/
598
599 /**
600 * struct usb_gadget_driver - driver for usb 'slave' devices
601 * @function: String describing the gadget's function
602 * @max_speed: Highest speed the driver handles.
603 * @setup: Invoked for ep0 control requests that aren't handled by
604 * the hardware level driver. Most calls must be handled by
605 * the gadget driver, including descriptor and configuration
606 * management. The 16 bit members of the setup data are in
607 * USB byte order. Called in_interrupt; this may not sleep. Driver
608 * queues a response to ep0, or returns negative to stall.
609 * @disconnect: Invoked after all transfers have been stopped,
610 * when the host is disconnected. May be called in_interrupt; this
611 * may not sleep. Some devices can't detect disconnect, so this might
612 * not be called except as part of controller shutdown.
613 * @bind: the driver's bind callback
614 * @unbind: Invoked when the driver is unbound from a gadget,
615 * usually from rmmod (after a disconnect is reported).
616 * Called in a context that permits sleeping.
617 * @suspend: Invoked on USB suspend. May be called in_interrupt.
618 * @resume: Invoked on USB resume. May be called in_interrupt.
619 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers
620 * and should be called in_interrupt.
621 * @driver: Driver model state for this driver.
622 * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL,
623 * this driver will be bound to any available UDC.
624 * @pending: UDC core private data used for deferred probe of this driver.
625 * @match_existing_only: If udc is not found, return an error and don't add this
626 * gadget driver to list of pending driver
627 *
628 * Devices are disabled till a gadget driver successfully bind()s, which
629 * means the driver will handle setup() requests needed to enumerate (and
630 * meet "chapter 9" requirements) then do some useful work.
631 *
632 * If gadget->is_otg is true, the gadget driver must provide an OTG
633 * descriptor during enumeration, or else fail the bind() call. In such
634 * cases, no USB traffic may flow until both bind() returns without
635 * having called usb_gadget_disconnect(), and the USB host stack has
636 * initialized.
637 *
638 * Drivers use hardware-specific knowledge to configure the usb hardware.
639 * endpoint addressing is only one of several hardware characteristics that
640 * are in descriptors the ep0 implementation returns from setup() calls.
641 *
642 * Except for ep0 implementation, most driver code shouldn't need change to
643 * run on top of different usb controllers. It'll use endpoints set up by
644 * that ep0 implementation.
645 *
646 * The usb controller driver handles a few standard usb requests. Those
647 * include set_address, and feature flags for devices, interfaces, and
648 * endpoints (the get_status, set_feature, and clear_feature requests).
649 *
650 * Accordingly, the driver's setup() callback must always implement all
651 * get_descriptor requests, returning at least a device descriptor and
652 * a configuration descriptor. Drivers must make sure the endpoint
653 * descriptors match any hardware constraints. Some hardware also constrains
654 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
655 *
656 * The driver's setup() callback must also implement set_configuration,
657 * and should also implement set_interface, get_configuration, and
658 * get_interface. Setting a configuration (or interface) is where
659 * endpoints should be activated or (config 0) shut down.
660 *
661 * (Note that only the default control endpoint is supported. Neither
662 * hosts nor devices generally support control traffic except to ep0.)
663 *
664 * Most devices will ignore USB suspend/resume operations, and so will
665 * not provide those callbacks. However, some may need to change modes
666 * when the host is not longer directing those activities. For example,
667 * local controls (buttons, dials, etc) may need to be re-enabled since
668 * the (remote) host can't do that any longer; or an error state might
669 * be cleared, to make the device behave identically whether or not
670 * power is maintained.
671 */
672 struct usb_gadget_driver {
673 char *function;
674 enum usb_device_speed max_speed;
675 int (*bind)(struct usb_gadget *gadget,
676 struct usb_gadget_driver *driver);
677 void (*unbind)(struct usb_gadget *);
678 int (*setup)(struct usb_gadget *,
679 const struct usb_ctrlrequest *);
680 void (*disconnect)(struct usb_gadget *);
681 void (*suspend)(struct usb_gadget *);
682 void (*resume)(struct usb_gadget *);
683 void (*reset)(struct usb_gadget *);
684
685 /* FIXME support safe rmmod */
686 struct device_driver driver;
687
688 char *udc_name;
689 struct list_head pending;
690 unsigned match_existing_only:1;
691 };
692
693
694
695 /*-------------------------------------------------------------------------*/
696
697 /* driver modules register and unregister, as usual.
698 * these calls must be made in a context that can sleep.
699 *
700 * these will usually be implemented directly by the hardware-dependent
701 * usb bus interface driver, which will only support a single driver.
702 */
703
704 /**
705 * usb_gadget_probe_driver - probe a gadget driver
706 * @driver: the driver being registered
707 * Context: can sleep
708 *
709 * Call this in your gadget driver's module initialization function,
710 * to tell the underlying usb controller driver about your driver.
711 * The @bind() function will be called to bind it to a gadget before this
712 * registration call returns. It's expected that the @bind() function will
713 * be in init sections.
714 */
715 int usb_gadget_probe_driver(struct usb_gadget_driver *driver);
716
717 /**
718 * usb_gadget_unregister_driver - unregister a gadget driver
719 * @driver:the driver being unregistered
720 * Context: can sleep
721 *
722 * Call this in your gadget driver's module cleanup function,
723 * to tell the underlying usb controller that your driver is
724 * going away. If the controller is connected to a USB host,
725 * it will first disconnect(). The driver is also requested
726 * to unbind() and clean up any device state, before this procedure
727 * finally returns. It's expected that the unbind() functions
728 * will in in exit sections, so may not be linked in some kernels.
729 */
730 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
731
732 extern int usb_add_gadget_udc_release(struct device *parent,
733 struct usb_gadget *gadget, void (*release)(struct device *dev));
734 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
735 extern void usb_del_gadget_udc(struct usb_gadget *gadget);
736 extern char *usb_get_gadget_udc_name(void);
737
738 /*-------------------------------------------------------------------------*/
739
740 /* utility to simplify dealing with string descriptors */
741
742 /**
743 * struct usb_string - wraps a C string and its USB id
744 * @id:the (nonzero) ID for this string
745 * @s:the string, in UTF-8 encoding
746 *
747 * If you're using usb_gadget_get_string(), use this to wrap a string
748 * together with its ID.
749 */
750 struct usb_string {
751 u8 id;
752 const char *s;
753 };
754
755 /**
756 * struct usb_gadget_strings - a set of USB strings in a given language
757 * @language:identifies the strings' language (0x0409 for en-us)
758 * @strings:array of strings with their ids
759 *
760 * If you're using usb_gadget_get_string(), use this to wrap all the
761 * strings for a given language.
762 */
763 struct usb_gadget_strings {
764 u16 language; /* 0x0409 for en-us */
765 struct usb_string *strings;
766 };
767
768 struct usb_gadget_string_container {
769 struct list_head list;
770 u8 *stash[0];
771 };
772
773 /* put descriptor for string with that id into buf (buflen >= 256) */
774 int usb_gadget_get_string(const struct usb_gadget_strings *table, int id, u8 *buf);
775
776 /*-------------------------------------------------------------------------*/
777
778 /* utility to simplify managing config descriptors */
779
780 /* write vector of descriptors into buffer */
781 int usb_descriptor_fillbuf(void *, unsigned,
782 const struct usb_descriptor_header **);
783
784 /* build config descriptor from single descriptor vector */
785 int usb_gadget_config_buf(const struct usb_config_descriptor *config,
786 void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
787
788 /* copy a NULL-terminated vector of descriptors */
789 struct usb_descriptor_header **usb_copy_descriptors(
790 struct usb_descriptor_header **);
791
792 /**
793 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors()
794 * @v: vector of descriptors
795 */
796 static inline void usb_free_descriptors(struct usb_descriptor_header **v)
797 {
798 kfree(v);
799 }
800
801 struct usb_function;
802 int usb_assign_descriptors(struct usb_function *f,
803 struct usb_descriptor_header **fs,
804 struct usb_descriptor_header **hs,
805 struct usb_descriptor_header **ss,
806 struct usb_descriptor_header **ssp);
807 void usb_free_all_descriptors(struct usb_function *f);
808
809 struct usb_descriptor_header *usb_otg_descriptor_alloc(
810 struct usb_gadget *gadget);
811 int usb_otg_descriptor_init(struct usb_gadget *gadget,
812 struct usb_descriptor_header *otg_desc);
813 /*-------------------------------------------------------------------------*/
814
815 /* utility to simplify map/unmap of usb_requests to/from DMA */
816
817 #ifdef CONFIG_HAS_DMA
818 extern int usb_gadget_map_request_by_dev(struct device *dev,
819 struct usb_request *req, int is_in);
820 extern int usb_gadget_map_request(struct usb_gadget *gadget,
821 struct usb_request *req, int is_in);
822
823 extern void usb_gadget_unmap_request_by_dev(struct device *dev,
824 struct usb_request *req, int is_in);
825 extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
826 struct usb_request *req, int is_in);
827 #else /* !CONFIG_HAS_DMA */
828 static inline int usb_gadget_map_request_by_dev(struct device *dev,
829 struct usb_request *req, int is_in) { return -ENOSYS; }
830 static inline int usb_gadget_map_request(struct usb_gadget *gadget,
831 struct usb_request *req, int is_in) { return -ENOSYS; }
832
833 static inline void usb_gadget_unmap_request_by_dev(struct device *dev,
834 struct usb_request *req, int is_in) { }
835 static inline void usb_gadget_unmap_request(struct usb_gadget *gadget,
836 struct usb_request *req, int is_in) { }
837 #endif /* !CONFIG_HAS_DMA */
838
839 /*-------------------------------------------------------------------------*/
840
841 /* utility to set gadget state properly */
842
843 extern void usb_gadget_set_state(struct usb_gadget *gadget,
844 enum usb_device_state state);
845
846 /*-------------------------------------------------------------------------*/
847
848 /* utility to tell udc core that the bus reset occurs */
849 extern void usb_gadget_udc_reset(struct usb_gadget *gadget,
850 struct usb_gadget_driver *driver);
851
852 /*-------------------------------------------------------------------------*/
853
854 /* utility to give requests back to the gadget layer */
855
856 extern void usb_gadget_giveback_request(struct usb_ep *ep,
857 struct usb_request *req);
858
859 /*-------------------------------------------------------------------------*/
860
861 /* utility to find endpoint by name */
862
863 extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g,
864 const char *name);
865
866 /*-------------------------------------------------------------------------*/
867
868 /* utility to check if endpoint caps match descriptor needs */
869
870 extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
871 struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
872 struct usb_ss_ep_comp_descriptor *ep_comp);
873
874 /*-------------------------------------------------------------------------*/
875
876 /* utility to update vbus status for udc core, it may be scheduled */
877 extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status);
878
879 /*-------------------------------------------------------------------------*/
880
881 /* utility wrapping a simple endpoint selection policy */
882
883 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
884 struct usb_endpoint_descriptor *);
885
886
887 extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *,
888 struct usb_endpoint_descriptor *,
889 struct usb_ss_ep_comp_descriptor *);
890
891 extern void usb_ep_autoconfig_release(struct usb_ep *);
892
893 extern void usb_ep_autoconfig_reset(struct usb_gadget *);
894
895 #endif /* __LINUX_USB_GADGET_H */