1 // SPDX-License-Identifier: GPL-2.0
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.
10 * (C) Copyright 2002-2004 by David Brownell
11 * All Rights Reserved.
13 * This software is licensed under the GNU GPL version 2.
16 #ifndef __LINUX_USB_GADGET_H
17 #define __LINUX_USB_GADGET_H
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>
29 #define UDC_TRACE_STR_MAX 512
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
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.
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).
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.
93 * NOTE: this is analogous to 'struct urb' on the host side, except that
94 * it's thinner and promotes more pre-allocation.
102 struct scatterlist *sg;
104 unsigned num_mapped_sgs;
106 unsigned stream_id:16;
107 unsigned no_interrupt:1;
109 unsigned short_not_ok:1;
110 unsigned dma_mapped:1;
112 void (*complete)(struct usb_ep *ep,
113 struct usb_request *req);
115 struct list_head list;
117 unsigned frame_number; /* ISO ONLY */
123 /*-------------------------------------------------------------------------*/
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...)
129 * note that device side usb controllers commonly differ in how many
130 * endpoints they support, as well as their capabilities.
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);
138 struct usb_request *(*alloc_request) (struct usb_ep *ep,
140 void (*free_request) (struct usb_ep *ep, struct usb_request *req);
142 int (*queue) (struct usb_ep *ep, struct usb_request *req,
144 int (*dequeue) (struct usb_ep *ep, struct usb_request *req);
146 int (*set_halt) (struct usb_ep *ep, int value);
147 int (*set_wedge) (struct usb_ep *ep);
149 int (*fifo_status) (struct usb_ep *ep);
150 void (*fifo_flush) (struct usb_ep *ep);
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.
163 unsigned type_control:1;
165 unsigned type_bulk:1;
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)
181 #define USB_EP_CAPS(_type, _dir) \
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), \
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
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.
226 const struct usb_ep_ops *ops;
227 struct list_head ep_list;
228 struct usb_ep_caps caps;
231 unsigned maxpacket:16;
232 unsigned maxpacket_limit:16;
233 unsigned max_streams:16;
237 const struct usb_endpoint_descriptor *desc;
238 const struct usb_ss_ep_comp_descriptor *comp_desc;
241 /*-------------------------------------------------------------------------*/
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);
257 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
258 unsigned maxpacket_limit)
260 static inline int usb_ep_enable(struct usb_ep *ep)
262 static inline int usb_ep_disable(struct usb_ep *ep)
264 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
267 static inline void usb_ep_free_request(struct usb_ep *ep,
268 struct usb_request *req)
270 static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req,
273 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
275 static inline int usb_ep_set_halt(struct usb_ep *ep)
277 static inline int usb_ep_clear_halt(struct usb_ep *ep)
279 static inline int usb_ep_set_wedge(struct usb_ep *ep)
281 static inline int usb_ep_fifo_status(struct usb_ep *ep)
283 static inline void usb_ep_fifo_flush(struct usb_ep *ep)
285 #endif /* USB_GADGET */
287 /*-------------------------------------------------------------------------*/
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 */
298 struct usb_gadget_driver;
301 /* the rest of the api to the controller hardware: device operations,
302 * which don't involve endpoints (or i/o).
304 struct usb_gadget_ops {
305 int (*get_frame)(struct usb_gadget *);
306 int (*wakeup)(struct usb_gadget *);
307 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
308 int (*vbus_session) (struct usb_gadget *, int is_active);
309 int (*vbus_draw) (struct usb_gadget *, unsigned mA);
310 int (*pullup) (struct usb_gadget *, int is_on);
311 int (*ioctl)(struct usb_gadget *,
312 unsigned code, unsigned long param);
313 void (*get_config_params)(struct usb_gadget *,
314 struct usb_dcd_config_params *);
315 int (*udc_start)(struct usb_gadget *,
316 struct usb_gadget_driver *);
317 int (*udc_stop)(struct usb_gadget *);
318 void (*udc_set_speed)(struct usb_gadget *, enum usb_device_speed);
319 struct usb_ep *(*match_ep)(struct usb_gadget *,
320 struct usb_endpoint_descriptor *,
321 struct usb_ss_ep_comp_descriptor *);
325 * struct usb_gadget - represents a usb slave device
326 * @work: (internal use) Workqueue to be used for sysfs_notify()
327 * @udc: struct usb_udc pointer for this gadget
328 * @ops: Function pointers used to access hardware-specific operations.
329 * @ep0: Endpoint zero, used when reading or writing responses to
330 * driver setup() requests
331 * @ep_list: List of other endpoints supported by the device.
332 * @speed: Speed of current connection to USB host.
333 * @max_speed: Maximal speed the UDC can handle. UDC must support this
334 * and all slower speeds.
335 * @state: the state we are now (attached, suspended, configured, etc)
336 * @name: Identifies the controller hardware type. Used in diagnostics
337 * and sometimes configuration.
338 * @dev: Driver model state for this abstract device.
339 * @isoch_delay: value from Set Isoch Delay request. Only valid on SS/SSP
340 * @out_epnum: last used out ep number
341 * @in_epnum: last used in ep number
342 * @mA: last set mA value
343 * @otg_caps: OTG capabilities of this gadget.
344 * @sg_supported: true if we can handle scatter-gather
345 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
346 * gadget driver must provide a USB OTG descriptor.
347 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable
348 * is in the Mini-AB jack, and HNP has been used to switch roles
349 * so that the "A" device currently acts as A-Peripheral, not A-Host.
350 * @a_hnp_support: OTG device feature flag, indicating that the A-Host
351 * supports HNP at this port.
352 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
353 * only supports HNP on a different root port.
354 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
355 * enabled HNP support.
356 * @hnp_polling_support: OTG device feature flag, indicating if the OTG device
357 * in peripheral mode can support HNP polling.
358 * @host_request_flag: OTG device feature flag, indicating if A-Peripheral
359 * or B-Peripheral wants to take host role.
360 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
362 * @quirk_altset_not_supp: UDC controller doesn't support alt settings.
363 * @quirk_stall_not_supp: UDC controller doesn't support stalling.
364 * @quirk_zlp_not_supp: UDC controller doesn't support ZLP.
365 * @quirk_avoids_skb_reserve: udc/platform wants to avoid skb_reserve() in
366 * u_ether.c to improve performance.
367 * @is_selfpowered: if the gadget is self-powered.
368 * @deactivated: True if gadget is deactivated - in deactivated state it cannot
370 * @connected: True if gadget is connected.
371 * @lpm_capable: If the gadget max_speed is FULL or HIGH, this flag
372 * indicates that it supports LPM as per the LPM ECN & errata.
374 * Gadgets have a mostly-portable "gadget driver" implementing device
375 * functions, handling all usb configurations and interfaces. Gadget
376 * drivers talk to hardware-specific code indirectly, through ops vectors.
377 * That insulates the gadget driver from hardware details, and packages
378 * the hardware endpoints through generic i/o queues. The "usb_gadget"
379 * and "usb_ep" interfaces provide that insulation from the hardware.
381 * Except for the driver data, all fields in this structure are
382 * read-only to the gadget driver. That driver data is part of the
383 * "driver model" infrastructure in 2.6 (and later) kernels, and for
384 * earlier systems is grouped in a similar structure that's not known
385 * to the rest of the kernel.
387 * Values of the three OTG device feature flags are updated before the
388 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
389 * driver suspend() calls. They are valid only when is_otg, and when the
390 * device is acting as a B-Peripheral (so is_a_peripheral is false).
393 struct work_struct work;
395 /* readonly to gadget driver */
396 const struct usb_gadget_ops *ops;
398 struct list_head ep_list; /* of usb_ep */
399 enum usb_device_speed speed;
400 enum usb_device_speed max_speed;
401 enum usb_device_state state;
404 unsigned isoch_delay;
408 struct usb_otg_caps *otg_caps;
410 unsigned sg_supported:1;
412 unsigned is_a_peripheral:1;
413 unsigned b_hnp_enable:1;
414 unsigned a_hnp_support:1;
415 unsigned a_alt_hnp_support:1;
416 unsigned hnp_polling_support:1;
417 unsigned host_request_flag:1;
418 unsigned quirk_ep_out_aligned_size:1;
419 unsigned quirk_altset_not_supp:1;
420 unsigned quirk_stall_not_supp:1;
421 unsigned quirk_zlp_not_supp:1;
422 unsigned quirk_avoids_skb_reserve:1;
423 unsigned is_selfpowered:1;
424 unsigned deactivated:1;
425 unsigned connected:1;
426 unsigned lpm_capable:1;
428 #define work_to_gadget(w) (container_of((w), struct usb_gadget, work))
430 static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
431 { dev_set_drvdata(&gadget->dev, data); }
432 static inline void *get_gadget_data(struct usb_gadget *gadget)
433 { return dev_get_drvdata(&gadget->dev); }
434 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
436 return container_of(dev, struct usb_gadget, dev);
439 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
440 #define gadget_for_each_ep(tmp, gadget) \
441 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
444 * usb_ep_align - returns @len aligned to ep's maxpacketsize.
445 * @ep: the endpoint whose maxpacketsize is used to align @len
446 * @len: buffer size's length to align to @ep's maxpacketsize
448 * This helper is used to align buffer's size to an ep's maxpacketsize.
450 static inline size_t usb_ep_align(struct usb_ep *ep, size_t len)
452 int max_packet_size = (size_t)usb_endpoint_maxp(ep->desc) & 0x7ff;
454 return round_up(len, max_packet_size);
458 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget
459 * requires quirk_ep_out_aligned_size, otherwise returns len.
460 * @g: controller to check for quirk
461 * @ep: the endpoint whose maxpacketsize is used to align @len
462 * @len: buffer size's length to align to @ep's maxpacketsize
464 * This helper is used in case it's required for any reason to check and maybe
465 * align buffer's size to an ep's maxpacketsize.
468 usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len)
470 return g->quirk_ep_out_aligned_size ? usb_ep_align(ep, len) : len;
474 * gadget_is_altset_supported - return true iff the hardware supports
476 * @g: controller to check for quirk
478 static inline int gadget_is_altset_supported(struct usb_gadget *g)
480 return !g->quirk_altset_not_supp;
484 * gadget_is_stall_supported - return true iff the hardware supports stalling
485 * @g: controller to check for quirk
487 static inline int gadget_is_stall_supported(struct usb_gadget *g)
489 return !g->quirk_stall_not_supp;
493 * gadget_is_zlp_supported - return true iff the hardware supports zlp
494 * @g: controller to check for quirk
496 static inline int gadget_is_zlp_supported(struct usb_gadget *g)
498 return !g->quirk_zlp_not_supp;
502 * gadget_avoids_skb_reserve - return true iff the hardware would like to avoid
503 * skb_reserve to improve performance.
504 * @g: controller to check for quirk
506 static inline int gadget_avoids_skb_reserve(struct usb_gadget *g)
508 return g->quirk_avoids_skb_reserve;
512 * gadget_is_dualspeed - return true iff the hardware handles high speed
513 * @g: controller that might support both high and full speeds
515 static inline int gadget_is_dualspeed(struct usb_gadget *g)
517 return g->max_speed >= USB_SPEED_HIGH;
521 * gadget_is_superspeed() - return true if the hardware handles superspeed
522 * @g: controller that might support superspeed
524 static inline int gadget_is_superspeed(struct usb_gadget *g)
526 return g->max_speed >= USB_SPEED_SUPER;
530 * gadget_is_superspeed_plus() - return true if the hardware handles
532 * @g: controller that might support superspeed plus
534 static inline int gadget_is_superspeed_plus(struct usb_gadget *g)
536 return g->max_speed >= USB_SPEED_SUPER_PLUS;
540 * gadget_is_otg - return true iff the hardware is OTG-ready
541 * @g: controller that might have a Mini-AB connector
543 * This is a runtime test, since kernels with a USB-OTG stack sometimes
544 * run on boards which only have a Mini-B (or Mini-A) connector.
546 static inline int gadget_is_otg(struct usb_gadget *g)
548 #ifdef CONFIG_USB_OTG
555 /*-------------------------------------------------------------------------*/
557 #if IS_ENABLED(CONFIG_USB_GADGET)
558 int usb_gadget_frame_number(struct usb_gadget *gadget);
559 int usb_gadget_wakeup(struct usb_gadget *gadget);
560 int usb_gadget_set_selfpowered(struct usb_gadget *gadget);
561 int usb_gadget_clear_selfpowered(struct usb_gadget *gadget);
562 int usb_gadget_vbus_connect(struct usb_gadget *gadget);
563 int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA);
564 int usb_gadget_vbus_disconnect(struct usb_gadget *gadget);
565 int usb_gadget_connect(struct usb_gadget *gadget);
566 int usb_gadget_disconnect(struct usb_gadget *gadget);
567 int usb_gadget_deactivate(struct usb_gadget *gadget);
568 int usb_gadget_activate(struct usb_gadget *gadget);
570 static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
572 static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
574 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
576 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
578 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
580 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
582 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
584 static inline int usb_gadget_connect(struct usb_gadget *gadget)
586 static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
588 static inline int usb_gadget_deactivate(struct usb_gadget *gadget)
590 static inline int usb_gadget_activate(struct usb_gadget *gadget)
592 #endif /* CONFIG_USB_GADGET */
594 /*-------------------------------------------------------------------------*/
597 * struct usb_gadget_driver - driver for usb 'slave' devices
598 * @function: String describing the gadget's function
599 * @max_speed: Highest speed the driver handles.
600 * @setup: Invoked for ep0 control requests that aren't handled by
601 * the hardware level driver. Most calls must be handled by
602 * the gadget driver, including descriptor and configuration
603 * management. The 16 bit members of the setup data are in
604 * USB byte order. Called in_interrupt; this may not sleep. Driver
605 * queues a response to ep0, or returns negative to stall.
606 * @disconnect: Invoked after all transfers have been stopped,
607 * when the host is disconnected. May be called in_interrupt; this
608 * may not sleep. Some devices can't detect disconnect, so this might
609 * not be called except as part of controller shutdown.
610 * @bind: the driver's bind callback
611 * @unbind: Invoked when the driver is unbound from a gadget,
612 * usually from rmmod (after a disconnect is reported).
613 * Called in a context that permits sleeping.
614 * @suspend: Invoked on USB suspend. May be called in_interrupt.
615 * @resume: Invoked on USB resume. May be called in_interrupt.
616 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers
617 * and should be called in_interrupt.
618 * @driver: Driver model state for this driver.
619 * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL,
620 * this driver will be bound to any available UDC.
621 * @pending: UDC core private data used for deferred probe of this driver.
622 * @match_existing_only: If udc is not found, return an error and don't add this
623 * gadget driver to list of pending driver
625 * Devices are disabled till a gadget driver successfully bind()s, which
626 * means the driver will handle setup() requests needed to enumerate (and
627 * meet "chapter 9" requirements) then do some useful work.
629 * If gadget->is_otg is true, the gadget driver must provide an OTG
630 * descriptor during enumeration, or else fail the bind() call. In such
631 * cases, no USB traffic may flow until both bind() returns without
632 * having called usb_gadget_disconnect(), and the USB host stack has
635 * Drivers use hardware-specific knowledge to configure the usb hardware.
636 * endpoint addressing is only one of several hardware characteristics that
637 * are in descriptors the ep0 implementation returns from setup() calls.
639 * Except for ep0 implementation, most driver code shouldn't need change to
640 * run on top of different usb controllers. It'll use endpoints set up by
641 * that ep0 implementation.
643 * The usb controller driver handles a few standard usb requests. Those
644 * include set_address, and feature flags for devices, interfaces, and
645 * endpoints (the get_status, set_feature, and clear_feature requests).
647 * Accordingly, the driver's setup() callback must always implement all
648 * get_descriptor requests, returning at least a device descriptor and
649 * a configuration descriptor. Drivers must make sure the endpoint
650 * descriptors match any hardware constraints. Some hardware also constrains
651 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
653 * The driver's setup() callback must also implement set_configuration,
654 * and should also implement set_interface, get_configuration, and
655 * get_interface. Setting a configuration (or interface) is where
656 * endpoints should be activated or (config 0) shut down.
658 * (Note that only the default control endpoint is supported. Neither
659 * hosts nor devices generally support control traffic except to ep0.)
661 * Most devices will ignore USB suspend/resume operations, and so will
662 * not provide those callbacks. However, some may need to change modes
663 * when the host is not longer directing those activities. For example,
664 * local controls (buttons, dials, etc) may need to be re-enabled since
665 * the (remote) host can't do that any longer; or an error state might
666 * be cleared, to make the device behave identically whether or not
667 * power is maintained.
669 struct usb_gadget_driver {
671 enum usb_device_speed max_speed;
672 int (*bind)(struct usb_gadget *gadget,
673 struct usb_gadget_driver *driver);
674 void (*unbind)(struct usb_gadget *);
675 int (*setup)(struct usb_gadget *,
676 const struct usb_ctrlrequest *);
677 void (*disconnect)(struct usb_gadget *);
678 void (*suspend)(struct usb_gadget *);
679 void (*resume)(struct usb_gadget *);
680 void (*reset)(struct usb_gadget *);
682 /* FIXME support safe rmmod */
683 struct device_driver driver;
686 struct list_head pending;
687 unsigned match_existing_only:1;
692 /*-------------------------------------------------------------------------*/
694 /* driver modules register and unregister, as usual.
695 * these calls must be made in a context that can sleep.
697 * these will usually be implemented directly by the hardware-dependent
698 * usb bus interface driver, which will only support a single driver.
702 * usb_gadget_probe_driver - probe a gadget driver
703 * @driver: the driver being registered
706 * Call this in your gadget driver's module initialization function,
707 * to tell the underlying usb controller driver about your driver.
708 * The @bind() function will be called to bind it to a gadget before this
709 * registration call returns. It's expected that the @bind() function will
710 * be in init sections.
712 int usb_gadget_probe_driver(struct usb_gadget_driver *driver);
715 * usb_gadget_unregister_driver - unregister a gadget driver
716 * @driver:the driver being unregistered
719 * Call this in your gadget driver's module cleanup function,
720 * to tell the underlying usb controller that your driver is
721 * going away. If the controller is connected to a USB host,
722 * it will first disconnect(). The driver is also requested
723 * to unbind() and clean up any device state, before this procedure
724 * finally returns. It's expected that the unbind() functions
725 * will in in exit sections, so may not be linked in some kernels.
727 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
729 extern int usb_add_gadget_udc_release(struct device *parent,
730 struct usb_gadget *gadget, void (*release)(struct device *dev));
731 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
732 extern void usb_del_gadget_udc(struct usb_gadget *gadget);
733 extern char *usb_get_gadget_udc_name(void);
735 /*-------------------------------------------------------------------------*/
737 /* utility to simplify dealing with string descriptors */
740 * struct usb_string - wraps a C string and its USB id
741 * @id:the (nonzero) ID for this string
742 * @s:the string, in UTF-8 encoding
744 * If you're using usb_gadget_get_string(), use this to wrap a string
745 * together with its ID.
753 * struct usb_gadget_strings - a set of USB strings in a given language
754 * @language:identifies the strings' language (0x0409 for en-us)
755 * @strings:array of strings with their ids
757 * If you're using usb_gadget_get_string(), use this to wrap all the
758 * strings for a given language.
760 struct usb_gadget_strings {
761 u16 language; /* 0x0409 for en-us */
762 struct usb_string *strings;
765 struct usb_gadget_string_container {
766 struct list_head list;
770 /* put descriptor for string with that id into buf (buflen >= 256) */
771 int usb_gadget_get_string(const struct usb_gadget_strings *table, int id, u8 *buf);
773 /*-------------------------------------------------------------------------*/
775 /* utility to simplify managing config descriptors */
777 /* write vector of descriptors into buffer */
778 int usb_descriptor_fillbuf(void *, unsigned,
779 const struct usb_descriptor_header **);
781 /* build config descriptor from single descriptor vector */
782 int usb_gadget_config_buf(const struct usb_config_descriptor *config,
783 void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
785 /* copy a NULL-terminated vector of descriptors */
786 struct usb_descriptor_header **usb_copy_descriptors(
787 struct usb_descriptor_header **);
790 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors()
791 * @v: vector of descriptors
793 static inline void usb_free_descriptors(struct usb_descriptor_header **v)
799 int usb_assign_descriptors(struct usb_function *f,
800 struct usb_descriptor_header **fs,
801 struct usb_descriptor_header **hs,
802 struct usb_descriptor_header **ss,
803 struct usb_descriptor_header **ssp);
804 void usb_free_all_descriptors(struct usb_function *f);
806 struct usb_descriptor_header *usb_otg_descriptor_alloc(
807 struct usb_gadget *gadget);
808 int usb_otg_descriptor_init(struct usb_gadget *gadget,
809 struct usb_descriptor_header *otg_desc);
810 /*-------------------------------------------------------------------------*/
812 /* utility to simplify map/unmap of usb_requests to/from DMA */
814 #ifdef CONFIG_HAS_DMA
815 extern int usb_gadget_map_request_by_dev(struct device *dev,
816 struct usb_request *req, int is_in);
817 extern int usb_gadget_map_request(struct usb_gadget *gadget,
818 struct usb_request *req, int is_in);
820 extern void usb_gadget_unmap_request_by_dev(struct device *dev,
821 struct usb_request *req, int is_in);
822 extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
823 struct usb_request *req, int is_in);
824 #else /* !CONFIG_HAS_DMA */
825 static inline int usb_gadget_map_request_by_dev(struct device *dev,
826 struct usb_request *req, int is_in) { return -ENOSYS; }
827 static inline int usb_gadget_map_request(struct usb_gadget *gadget,
828 struct usb_request *req, int is_in) { return -ENOSYS; }
830 static inline void usb_gadget_unmap_request_by_dev(struct device *dev,
831 struct usb_request *req, int is_in) { }
832 static inline void usb_gadget_unmap_request(struct usb_gadget *gadget,
833 struct usb_request *req, int is_in) { }
834 #endif /* !CONFIG_HAS_DMA */
836 /*-------------------------------------------------------------------------*/
838 /* utility to set gadget state properly */
840 extern void usb_gadget_set_state(struct usb_gadget *gadget,
841 enum usb_device_state state);
843 /*-------------------------------------------------------------------------*/
845 /* utility to tell udc core that the bus reset occurs */
846 extern void usb_gadget_udc_reset(struct usb_gadget *gadget,
847 struct usb_gadget_driver *driver);
849 /*-------------------------------------------------------------------------*/
851 /* utility to give requests back to the gadget layer */
853 extern void usb_gadget_giveback_request(struct usb_ep *ep,
854 struct usb_request *req);
856 /*-------------------------------------------------------------------------*/
858 /* utility to find endpoint by name */
860 extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g,
863 /*-------------------------------------------------------------------------*/
865 /* utility to check if endpoint caps match descriptor needs */
867 extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
868 struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
869 struct usb_ss_ep_comp_descriptor *ep_comp);
871 /*-------------------------------------------------------------------------*/
873 /* utility to update vbus status for udc core, it may be scheduled */
874 extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status);
876 /*-------------------------------------------------------------------------*/
878 /* utility wrapping a simple endpoint selection policy */
880 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
881 struct usb_endpoint_descriptor *);
884 extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *,
885 struct usb_endpoint_descriptor *,
886 struct usb_ss_ep_comp_descriptor *);
888 extern void usb_ep_autoconfig_release(struct usb_ep *);
890 extern void usb_ep_autoconfig_reset(struct usb_gadget *);
892 #endif /* __LINUX_USB_GADGET_H */