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.
9 * (C) Copyright 2002-2004 by David Brownell
10 * All Rights Reserved.
12 * This software is licensed under the GNU GPL version 2.
15 #ifndef __LINUX_USB_GADGET_H
16 #define __LINUX_USB_GADGET_H
18 #include <linux/device.h>
19 #include <linux/errno.h>
20 #include <linux/init.h>
21 #include <linux/list.h>
22 #include <linux/slab.h>
23 #include <linux/scatterlist.h>
24 #include <linux/types.h>
25 #include <linux/workqueue.h>
26 #include <linux/usb/ch9.h>
28 #define UDC_TRACE_STR_MAX 512
33 * struct usb_request - describes one i/o request
34 * @buf: Buffer used for data. Always provide this; some controllers
35 * only use PIO, or don't use DMA for some endpoints.
36 * @dma: DMA address corresponding to 'buf'. If you don't set this
37 * field, and the usb controller needs one, it is responsible
38 * for mapping and unmapping the buffer.
39 * @sg: a scatterlist for SG-capable controllers.
40 * @num_sgs: number of SG entries
41 * @num_mapped_sgs: number of SG entries mapped to DMA (internal)
42 * @length: Length of that data
43 * @stream_id: The stream id, when USB3.0 bulk streams are being used
44 * @no_interrupt: If true, hints that no completion irq is needed.
45 * Helpful sometimes with deep request queues that are handled
46 * directly by DMA controllers.
47 * @zero: If true, when writing data, makes the last packet be "short"
48 * by adding a zero length packet as needed;
49 * @short_not_ok: When reading data, makes short packets be
50 * treated as errors (queue stops advancing till cleanup).
51 * @complete: Function called when request completes, so this request and
52 * its buffer may be re-used. The function will always be called with
53 * interrupts disabled, and it must not sleep.
54 * Reads terminate with a short packet, or when the buffer fills,
55 * whichever comes first. When writes terminate, some data bytes
56 * will usually still be in flight (often in a hardware fifo).
57 * Errors (for reads or writes) stop the queue from advancing
58 * until the completion function returns, so that any transfers
59 * invalidated by the error may first be dequeued.
60 * @context: For use by the completion callback
61 * @list: For use by the gadget driver.
62 * @status: Reports completion code, zero or a negative errno.
63 * Normally, faults block the transfer queue from advancing until
64 * the completion callback returns.
65 * Code "-ESHUTDOWN" indicates completion caused by device disconnect,
66 * or when the driver disabled the endpoint.
67 * @actual: Reports bytes transferred to/from the buffer. For reads (OUT
68 * transfers) this may be less than the requested length. If the
69 * short_not_ok flag is set, short reads are treated as errors
70 * even when status otherwise indicates successful completion.
71 * Note that for writes (IN transfers) some data bytes may still
72 * reside in a device-side FIFO when the request is reported as
75 * These are allocated/freed through the endpoint they're used with. The
76 * hardware's driver can add extra per-request data to the memory it returns,
77 * which often avoids separate memory allocations (potential failures),
78 * later when the request is queued.
80 * Request flags affect request handling, such as whether a zero length
81 * packet is written (the "zero" flag), whether a short read should be
82 * treated as an error (blocking request queue advance, the "short_not_ok"
83 * flag), or hinting that an interrupt is not required (the "no_interrupt"
84 * flag, for use with deep request queues).
86 * Bulk endpoints can use any size buffers, and can also be used for interrupt
87 * transfers. interrupt-only endpoints can be much less functional.
89 * NOTE: this is analogous to 'struct urb' on the host side, except that
90 * it's thinner and promotes more pre-allocation.
98 struct scatterlist
*sg
;
100 unsigned num_mapped_sgs
;
102 unsigned stream_id
:16;
103 unsigned no_interrupt
:1;
105 unsigned short_not_ok
:1;
107 void (*complete
)(struct usb_ep
*ep
,
108 struct usb_request
*req
);
110 struct list_head list
;
116 /*-------------------------------------------------------------------------*/
118 /* endpoint-specific parts of the api to the usb controller hardware.
119 * unlike the urb model, (de)multiplexing layers are not required.
120 * (so this api could slash overhead if used on the host side...)
122 * note that device side usb controllers commonly differ in how many
123 * endpoints they support, as well as their capabilities.
126 int (*enable
) (struct usb_ep
*ep
,
127 const struct usb_endpoint_descriptor
*desc
);
128 int (*disable
) (struct usb_ep
*ep
);
130 struct usb_request
*(*alloc_request
) (struct usb_ep
*ep
,
132 void (*free_request
) (struct usb_ep
*ep
, struct usb_request
*req
);
134 int (*queue
) (struct usb_ep
*ep
, struct usb_request
*req
,
136 int (*dequeue
) (struct usb_ep
*ep
, struct usb_request
*req
);
138 int (*set_halt
) (struct usb_ep
*ep
, int value
);
139 int (*set_wedge
) (struct usb_ep
*ep
);
141 int (*fifo_status
) (struct usb_ep
*ep
);
142 void (*fifo_flush
) (struct usb_ep
*ep
);
146 * struct usb_ep_caps - endpoint capabilities description
147 * @type_control:Endpoint supports control type (reserved for ep0).
148 * @type_iso:Endpoint supports isochronous transfers.
149 * @type_bulk:Endpoint supports bulk transfers.
150 * @type_int:Endpoint supports interrupt transfers.
151 * @dir_in:Endpoint supports IN direction.
152 * @dir_out:Endpoint supports OUT direction.
155 unsigned type_control
:1;
157 unsigned type_bulk
:1;
163 #define USB_EP_CAPS_TYPE_CONTROL 0x01
164 #define USB_EP_CAPS_TYPE_ISO 0x02
165 #define USB_EP_CAPS_TYPE_BULK 0x04
166 #define USB_EP_CAPS_TYPE_INT 0x08
167 #define USB_EP_CAPS_TYPE_ALL \
168 (USB_EP_CAPS_TYPE_ISO | USB_EP_CAPS_TYPE_BULK | USB_EP_CAPS_TYPE_INT)
169 #define USB_EP_CAPS_DIR_IN 0x01
170 #define USB_EP_CAPS_DIR_OUT 0x02
171 #define USB_EP_CAPS_DIR_ALL (USB_EP_CAPS_DIR_IN | USB_EP_CAPS_DIR_OUT)
173 #define USB_EP_CAPS(_type, _dir) \
175 .type_control = !!(_type & USB_EP_CAPS_TYPE_CONTROL), \
176 .type_iso = !!(_type & USB_EP_CAPS_TYPE_ISO), \
177 .type_bulk = !!(_type & USB_EP_CAPS_TYPE_BULK), \
178 .type_int = !!(_type & USB_EP_CAPS_TYPE_INT), \
179 .dir_in = !!(_dir & USB_EP_CAPS_DIR_IN), \
180 .dir_out = !!(_dir & USB_EP_CAPS_DIR_OUT), \
184 * struct usb_ep - device side representation of USB endpoint
185 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk"
186 * @ops: Function pointers used to access hardware-specific operations.
187 * @ep_list:the gadget's ep_list holds all of its endpoints
188 * @caps:The structure describing types and directions supported by endoint.
189 * @maxpacket:The maximum packet size used on this endpoint. The initial
190 * value can sometimes be reduced (hardware allowing), according to
191 * the endpoint descriptor used to configure the endpoint.
192 * @maxpacket_limit:The maximum packet size value which can be handled by this
193 * endpoint. It's set once by UDC driver when endpoint is initialized, and
194 * should not be changed. Should not be confused with maxpacket.
195 * @max_streams: The maximum number of streams supported
196 * by this EP (0 - 16, actual number is 2^n)
197 * @mult: multiplier, 'mult' value for SS Isoc EPs
198 * @maxburst: the maximum number of bursts supported by this EP (for usb3)
199 * @driver_data:for use by the gadget driver.
200 * @address: used to identify the endpoint when finding descriptor that
201 * matches connection speed
202 * @desc: endpoint descriptor. This pointer is set before the endpoint is
203 * enabled and remains valid until the endpoint is disabled.
204 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion
205 * descriptor that is used to configure the endpoint
207 * the bus controller driver lists all the general purpose endpoints in
208 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list,
209 * and is accessed only in response to a driver setup() callback.
216 const struct usb_ep_ops
*ops
;
217 struct list_head ep_list
;
218 struct usb_ep_caps caps
;
221 unsigned maxpacket
:16;
222 unsigned maxpacket_limit
:16;
223 unsigned max_streams
:16;
227 const struct usb_endpoint_descriptor
*desc
;
228 const struct usb_ss_ep_comp_descriptor
*comp_desc
;
231 /*-------------------------------------------------------------------------*/
233 #if IS_ENABLED(CONFIG_USB_GADGET)
234 void usb_ep_set_maxpacket_limit(struct usb_ep
*ep
, unsigned maxpacket_limit
);
235 int usb_ep_enable(struct usb_ep
*ep
);
236 int usb_ep_disable(struct usb_ep
*ep
);
237 struct usb_request
*usb_ep_alloc_request(struct usb_ep
*ep
, gfp_t gfp_flags
);
238 void usb_ep_free_request(struct usb_ep
*ep
, struct usb_request
*req
);
239 int usb_ep_queue(struct usb_ep
*ep
, struct usb_request
*req
, gfp_t gfp_flags
);
240 int usb_ep_dequeue(struct usb_ep
*ep
, struct usb_request
*req
);
241 int usb_ep_set_halt(struct usb_ep
*ep
);
242 int usb_ep_clear_halt(struct usb_ep
*ep
);
243 int usb_ep_set_wedge(struct usb_ep
*ep
);
244 int usb_ep_fifo_status(struct usb_ep
*ep
);
245 void usb_ep_fifo_flush(struct usb_ep
*ep
);
247 static inline void usb_ep_set_maxpacket_limit(struct usb_ep
*ep
,
248 unsigned maxpacket_limit
)
250 static inline int usb_ep_enable(struct usb_ep
*ep
)
252 static inline int usb_ep_disable(struct usb_ep
*ep
)
254 static inline struct usb_request
*usb_ep_alloc_request(struct usb_ep
*ep
,
257 static inline void usb_ep_free_request(struct usb_ep
*ep
,
258 struct usb_request
*req
)
260 static inline int usb_ep_queue(struct usb_ep
*ep
, struct usb_request
*req
,
263 static inline int usb_ep_dequeue(struct usb_ep
*ep
, struct usb_request
*req
)
265 static inline int usb_ep_set_halt(struct usb_ep
*ep
)
267 static inline int usb_ep_clear_halt(struct usb_ep
*ep
)
269 static inline int usb_ep_set_wedge(struct usb_ep
*ep
)
271 static inline int usb_ep_fifo_status(struct usb_ep
*ep
)
273 static inline void usb_ep_fifo_flush(struct usb_ep
*ep
)
275 #endif /* USB_GADGET */
277 /*-------------------------------------------------------------------------*/
279 struct usb_dcd_config_params
{
280 __u8 bU1devExitLat
; /* U1 Device exit Latency */
281 #define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */
282 __le16 bU2DevExitLat
; /* U2 Device exit Latency */
283 #define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */
288 struct usb_gadget_driver
;
291 /* the rest of the api to the controller hardware: device operations,
292 * which don't involve endpoints (or i/o).
294 struct usb_gadget_ops
{
295 int (*get_frame
)(struct usb_gadget
*);
296 int (*wakeup
)(struct usb_gadget
*);
297 int (*set_selfpowered
) (struct usb_gadget
*, int is_selfpowered
);
298 int (*vbus_session
) (struct usb_gadget
*, int is_active
);
299 int (*vbus_draw
) (struct usb_gadget
*, unsigned mA
);
300 int (*pullup
) (struct usb_gadget
*, int is_on
);
301 int (*ioctl
)(struct usb_gadget
*,
302 unsigned code
, unsigned long param
);
303 void (*get_config_params
)(struct usb_dcd_config_params
*);
304 int (*udc_start
)(struct usb_gadget
*,
305 struct usb_gadget_driver
*);
306 int (*udc_stop
)(struct usb_gadget
*);
307 struct usb_ep
*(*match_ep
)(struct usb_gadget
*,
308 struct usb_endpoint_descriptor
*,
309 struct usb_ss_ep_comp_descriptor
*);
313 * struct usb_gadget - represents a usb slave device
314 * @work: (internal use) Workqueue to be used for sysfs_notify()
315 * @udc: struct usb_udc pointer for this gadget
316 * @ops: Function pointers used to access hardware-specific operations.
317 * @ep0: Endpoint zero, used when reading or writing responses to
318 * driver setup() requests
319 * @ep_list: List of other endpoints supported by the device.
320 * @speed: Speed of current connection to USB host.
321 * @max_speed: Maximal speed the UDC can handle. UDC must support this
322 * and all slower speeds.
323 * @state: the state we are now (attached, suspended, configured, etc)
324 * @name: Identifies the controller hardware type. Used in diagnostics
325 * and sometimes configuration.
326 * @dev: Driver model state for this abstract device.
327 * @out_epnum: last used out ep number
328 * @in_epnum: last used in ep number
329 * @mA: last set mA value
330 * @otg_caps: OTG capabilities of this gadget.
331 * @sg_supported: true if we can handle scatter-gather
332 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
333 * gadget driver must provide a USB OTG descriptor.
334 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable
335 * is in the Mini-AB jack, and HNP has been used to switch roles
336 * so that the "A" device currently acts as A-Peripheral, not A-Host.
337 * @a_hnp_support: OTG device feature flag, indicating that the A-Host
338 * supports HNP at this port.
339 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
340 * only supports HNP on a different root port.
341 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
342 * enabled HNP support.
343 * @hnp_polling_support: OTG device feature flag, indicating if the OTG device
344 * in peripheral mode can support HNP polling.
345 * @host_request_flag: OTG device feature flag, indicating if A-Peripheral
346 * or B-Peripheral wants to take host role.
347 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
349 * @quirk_avoids_skb_reserve: udc/platform wants to avoid skb_reserve() in
350 * u_ether.c to improve performance.
351 * @is_selfpowered: if the gadget is self-powered.
352 * @deactivated: True if gadget is deactivated - in deactivated state it cannot
354 * @connected: True if gadget is connected.
356 * Gadgets have a mostly-portable "gadget driver" implementing device
357 * functions, handling all usb configurations and interfaces. Gadget
358 * drivers talk to hardware-specific code indirectly, through ops vectors.
359 * That insulates the gadget driver from hardware details, and packages
360 * the hardware endpoints through generic i/o queues. The "usb_gadget"
361 * and "usb_ep" interfaces provide that insulation from the hardware.
363 * Except for the driver data, all fields in this structure are
364 * read-only to the gadget driver. That driver data is part of the
365 * "driver model" infrastructure in 2.6 (and later) kernels, and for
366 * earlier systems is grouped in a similar structure that's not known
367 * to the rest of the kernel.
369 * Values of the three OTG device feature flags are updated before the
370 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
371 * driver suspend() calls. They are valid only when is_otg, and when the
372 * device is acting as a B-Peripheral (so is_a_peripheral is false).
375 struct work_struct work
;
377 /* readonly to gadget driver */
378 const struct usb_gadget_ops
*ops
;
380 struct list_head ep_list
; /* of usb_ep */
381 enum usb_device_speed speed
;
382 enum usb_device_speed max_speed
;
383 enum usb_device_state state
;
389 struct usb_otg_caps
*otg_caps
;
391 unsigned sg_supported
:1;
393 unsigned is_a_peripheral
:1;
394 unsigned b_hnp_enable
:1;
395 unsigned a_hnp_support
:1;
396 unsigned a_alt_hnp_support
:1;
397 unsigned hnp_polling_support
:1;
398 unsigned host_request_flag
:1;
399 unsigned quirk_ep_out_aligned_size
:1;
400 unsigned quirk_altset_not_supp
:1;
401 unsigned quirk_stall_not_supp
:1;
402 unsigned quirk_zlp_not_supp
:1;
403 unsigned quirk_avoids_skb_reserve
:1;
404 unsigned is_selfpowered
:1;
405 unsigned deactivated
:1;
406 unsigned connected
:1;
408 #define work_to_gadget(w) (container_of((w), struct usb_gadget, work))
410 static inline void set_gadget_data(struct usb_gadget
*gadget
, void *data
)
411 { dev_set_drvdata(&gadget
->dev
, data
); }
412 static inline void *get_gadget_data(struct usb_gadget
*gadget
)
413 { return dev_get_drvdata(&gadget
->dev
); }
414 static inline struct usb_gadget
*dev_to_usb_gadget(struct device
*dev
)
416 return container_of(dev
, struct usb_gadget
, dev
);
419 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
420 #define gadget_for_each_ep(tmp, gadget) \
421 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
424 * usb_ep_align - returns @len aligned to ep's maxpacketsize.
425 * @ep: the endpoint whose maxpacketsize is used to align @len
426 * @len: buffer size's length to align to @ep's maxpacketsize
428 * This helper is used to align buffer's size to an ep's maxpacketsize.
430 static inline size_t usb_ep_align(struct usb_ep
*ep
, size_t len
)
432 int max_packet_size
= (size_t)usb_endpoint_maxp(ep
->desc
) & 0x7ff;
434 return round_up(len
, max_packet_size
);
438 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget
439 * requires quirk_ep_out_aligned_size, otherwise returns len.
440 * @g: controller to check for quirk
441 * @ep: the endpoint whose maxpacketsize is used to align @len
442 * @len: buffer size's length to align to @ep's maxpacketsize
444 * This helper is used in case it's required for any reason to check and maybe
445 * align buffer's size to an ep's maxpacketsize.
448 usb_ep_align_maybe(struct usb_gadget
*g
, struct usb_ep
*ep
, size_t len
)
450 return g
->quirk_ep_out_aligned_size
? usb_ep_align(ep
, len
) : len
;
454 * gadget_is_altset_supported - return true iff the hardware supports
456 * @g: controller to check for quirk
458 static inline int gadget_is_altset_supported(struct usb_gadget
*g
)
460 return !g
->quirk_altset_not_supp
;
464 * gadget_is_stall_supported - return true iff the hardware supports stalling
465 * @g: controller to check for quirk
467 static inline int gadget_is_stall_supported(struct usb_gadget
*g
)
469 return !g
->quirk_stall_not_supp
;
473 * gadget_is_zlp_supported - return true iff the hardware supports zlp
474 * @g: controller to check for quirk
476 static inline int gadget_is_zlp_supported(struct usb_gadget
*g
)
478 return !g
->quirk_zlp_not_supp
;
482 * gadget_avoids_skb_reserve - return true iff the hardware would like to avoid
483 * skb_reserve to improve performance.
484 * @g: controller to check for quirk
486 static inline int gadget_avoids_skb_reserve(struct usb_gadget
*g
)
488 return g
->quirk_avoids_skb_reserve
;
492 * gadget_is_dualspeed - return true iff the hardware handles high speed
493 * @g: controller that might support both high and full speeds
495 static inline int gadget_is_dualspeed(struct usb_gadget
*g
)
497 return g
->max_speed
>= USB_SPEED_HIGH
;
501 * gadget_is_superspeed() - return true if the hardware handles superspeed
502 * @g: controller that might support superspeed
504 static inline int gadget_is_superspeed(struct usb_gadget
*g
)
506 return g
->max_speed
>= USB_SPEED_SUPER
;
510 * gadget_is_superspeed_plus() - return true if the hardware handles
512 * @g: controller that might support superspeed plus
514 static inline int gadget_is_superspeed_plus(struct usb_gadget
*g
)
516 return g
->max_speed
>= USB_SPEED_SUPER_PLUS
;
520 * gadget_is_otg - return true iff the hardware is OTG-ready
521 * @g: controller that might have a Mini-AB connector
523 * This is a runtime test, since kernels with a USB-OTG stack sometimes
524 * run on boards which only have a Mini-B (or Mini-A) connector.
526 static inline int gadget_is_otg(struct usb_gadget
*g
)
528 #ifdef CONFIG_USB_OTG
535 /*-------------------------------------------------------------------------*/
537 #if IS_ENABLED(CONFIG_USB_GADGET)
538 int usb_gadget_frame_number(struct usb_gadget
*gadget
);
539 int usb_gadget_wakeup(struct usb_gadget
*gadget
);
540 int usb_gadget_set_selfpowered(struct usb_gadget
*gadget
);
541 int usb_gadget_clear_selfpowered(struct usb_gadget
*gadget
);
542 int usb_gadget_vbus_connect(struct usb_gadget
*gadget
);
543 int usb_gadget_vbus_draw(struct usb_gadget
*gadget
, unsigned mA
);
544 int usb_gadget_vbus_disconnect(struct usb_gadget
*gadget
);
545 int usb_gadget_connect(struct usb_gadget
*gadget
);
546 int usb_gadget_disconnect(struct usb_gadget
*gadget
);
547 int usb_gadget_deactivate(struct usb_gadget
*gadget
);
548 int usb_gadget_activate(struct usb_gadget
*gadget
);
550 static inline int usb_gadget_frame_number(struct usb_gadget
*gadget
)
552 static inline int usb_gadget_wakeup(struct usb_gadget
*gadget
)
554 static inline int usb_gadget_set_selfpowered(struct usb_gadget
*gadget
)
556 static inline int usb_gadget_clear_selfpowered(struct usb_gadget
*gadget
)
558 static inline int usb_gadget_vbus_connect(struct usb_gadget
*gadget
)
560 static inline int usb_gadget_vbus_draw(struct usb_gadget
*gadget
, unsigned mA
)
562 static inline int usb_gadget_vbus_disconnect(struct usb_gadget
*gadget
)
564 static inline int usb_gadget_connect(struct usb_gadget
*gadget
)
566 static inline int usb_gadget_disconnect(struct usb_gadget
*gadget
)
568 static inline int usb_gadget_deactivate(struct usb_gadget
*gadget
)
570 static inline int usb_gadget_activate(struct usb_gadget
*gadget
)
572 #endif /* CONFIG_USB_GADGET */
574 /*-------------------------------------------------------------------------*/
577 * struct usb_gadget_driver - driver for usb 'slave' devices
578 * @function: String describing the gadget's function
579 * @max_speed: Highest speed the driver handles.
580 * @setup: Invoked for ep0 control requests that aren't handled by
581 * the hardware level driver. Most calls must be handled by
582 * the gadget driver, including descriptor and configuration
583 * management. The 16 bit members of the setup data are in
584 * USB byte order. Called in_interrupt; this may not sleep. Driver
585 * queues a response to ep0, or returns negative to stall.
586 * @disconnect: Invoked after all transfers have been stopped,
587 * when the host is disconnected. May be called in_interrupt; this
588 * may not sleep. Some devices can't detect disconnect, so this might
589 * not be called except as part of controller shutdown.
590 * @bind: the driver's bind callback
591 * @unbind: Invoked when the driver is unbound from a gadget,
592 * usually from rmmod (after a disconnect is reported).
593 * Called in a context that permits sleeping.
594 * @suspend: Invoked on USB suspend. May be called in_interrupt.
595 * @resume: Invoked on USB resume. May be called in_interrupt.
596 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers
597 * and should be called in_interrupt.
598 * @driver: Driver model state for this driver.
599 * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL,
600 * this driver will be bound to any available UDC.
601 * @pending: UDC core private data used for deferred probe of this driver.
602 * @match_existing_only: If udc is not found, return an error and don't add this
603 * gadget driver to list of pending driver
605 * Devices are disabled till a gadget driver successfully bind()s, which
606 * means the driver will handle setup() requests needed to enumerate (and
607 * meet "chapter 9" requirements) then do some useful work.
609 * If gadget->is_otg is true, the gadget driver must provide an OTG
610 * descriptor during enumeration, or else fail the bind() call. In such
611 * cases, no USB traffic may flow until both bind() returns without
612 * having called usb_gadget_disconnect(), and the USB host stack has
615 * Drivers use hardware-specific knowledge to configure the usb hardware.
616 * endpoint addressing is only one of several hardware characteristics that
617 * are in descriptors the ep0 implementation returns from setup() calls.
619 * Except for ep0 implementation, most driver code shouldn't need change to
620 * run on top of different usb controllers. It'll use endpoints set up by
621 * that ep0 implementation.
623 * The usb controller driver handles a few standard usb requests. Those
624 * include set_address, and feature flags for devices, interfaces, and
625 * endpoints (the get_status, set_feature, and clear_feature requests).
627 * Accordingly, the driver's setup() callback must always implement all
628 * get_descriptor requests, returning at least a device descriptor and
629 * a configuration descriptor. Drivers must make sure the endpoint
630 * descriptors match any hardware constraints. Some hardware also constrains
631 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
633 * The driver's setup() callback must also implement set_configuration,
634 * and should also implement set_interface, get_configuration, and
635 * get_interface. Setting a configuration (or interface) is where
636 * endpoints should be activated or (config 0) shut down.
638 * (Note that only the default control endpoint is supported. Neither
639 * hosts nor devices generally support control traffic except to ep0.)
641 * Most devices will ignore USB suspend/resume operations, and so will
642 * not provide those callbacks. However, some may need to change modes
643 * when the host is not longer directing those activities. For example,
644 * local controls (buttons, dials, etc) may need to be re-enabled since
645 * the (remote) host can't do that any longer; or an error state might
646 * be cleared, to make the device behave identically whether or not
647 * power is maintained.
649 struct usb_gadget_driver
{
651 enum usb_device_speed max_speed
;
652 int (*bind
)(struct usb_gadget
*gadget
,
653 struct usb_gadget_driver
*driver
);
654 void (*unbind
)(struct usb_gadget
*);
655 int (*setup
)(struct usb_gadget
*,
656 const struct usb_ctrlrequest
*);
657 void (*disconnect
)(struct usb_gadget
*);
658 void (*suspend
)(struct usb_gadget
*);
659 void (*resume
)(struct usb_gadget
*);
660 void (*reset
)(struct usb_gadget
*);
662 /* FIXME support safe rmmod */
663 struct device_driver driver
;
666 struct list_head pending
;
667 unsigned match_existing_only
:1;
672 /*-------------------------------------------------------------------------*/
674 /* driver modules register and unregister, as usual.
675 * these calls must be made in a context that can sleep.
677 * these will usually be implemented directly by the hardware-dependent
678 * usb bus interface driver, which will only support a single driver.
682 * usb_gadget_probe_driver - probe a gadget driver
683 * @driver: the driver being registered
686 * Call this in your gadget driver's module initialization function,
687 * to tell the underlying usb controller driver about your driver.
688 * The @bind() function will be called to bind it to a gadget before this
689 * registration call returns. It's expected that the @bind() function will
690 * be in init sections.
692 int usb_gadget_probe_driver(struct usb_gadget_driver
*driver
);
695 * usb_gadget_unregister_driver - unregister a gadget driver
696 * @driver:the driver being unregistered
699 * Call this in your gadget driver's module cleanup function,
700 * to tell the underlying usb controller that your driver is
701 * going away. If the controller is connected to a USB host,
702 * it will first disconnect(). The driver is also requested
703 * to unbind() and clean up any device state, before this procedure
704 * finally returns. It's expected that the unbind() functions
705 * will in in exit sections, so may not be linked in some kernels.
707 int usb_gadget_unregister_driver(struct usb_gadget_driver
*driver
);
709 extern int usb_add_gadget_udc_release(struct device
*parent
,
710 struct usb_gadget
*gadget
, void (*release
)(struct device
*dev
));
711 extern int usb_add_gadget_udc(struct device
*parent
, struct usb_gadget
*gadget
);
712 extern void usb_del_gadget_udc(struct usb_gadget
*gadget
);
713 extern char *usb_get_gadget_udc_name(void);
715 /*-------------------------------------------------------------------------*/
717 /* utility to simplify dealing with string descriptors */
720 * struct usb_string - wraps a C string and its USB id
721 * @id:the (nonzero) ID for this string
722 * @s:the string, in UTF-8 encoding
724 * If you're using usb_gadget_get_string(), use this to wrap a string
725 * together with its ID.
733 * struct usb_gadget_strings - a set of USB strings in a given language
734 * @language:identifies the strings' language (0x0409 for en-us)
735 * @strings:array of strings with their ids
737 * If you're using usb_gadget_get_string(), use this to wrap all the
738 * strings for a given language.
740 struct usb_gadget_strings
{
741 u16 language
; /* 0x0409 for en-us */
742 struct usb_string
*strings
;
745 struct usb_gadget_string_container
{
746 struct list_head list
;
750 /* put descriptor for string with that id into buf (buflen >= 256) */
751 int usb_gadget_get_string(struct usb_gadget_strings
*table
, int id
, u8
*buf
);
753 /*-------------------------------------------------------------------------*/
755 /* utility to simplify managing config descriptors */
757 /* write vector of descriptors into buffer */
758 int usb_descriptor_fillbuf(void *, unsigned,
759 const struct usb_descriptor_header
**);
761 /* build config descriptor from single descriptor vector */
762 int usb_gadget_config_buf(const struct usb_config_descriptor
*config
,
763 void *buf
, unsigned buflen
, const struct usb_descriptor_header
**desc
);
765 /* copy a NULL-terminated vector of descriptors */
766 struct usb_descriptor_header
**usb_copy_descriptors(
767 struct usb_descriptor_header
**);
770 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors()
771 * @v: vector of descriptors
773 static inline void usb_free_descriptors(struct usb_descriptor_header
**v
)
779 int usb_assign_descriptors(struct usb_function
*f
,
780 struct usb_descriptor_header
**fs
,
781 struct usb_descriptor_header
**hs
,
782 struct usb_descriptor_header
**ss
,
783 struct usb_descriptor_header
**ssp
);
784 void usb_free_all_descriptors(struct usb_function
*f
);
786 struct usb_descriptor_header
*usb_otg_descriptor_alloc(
787 struct usb_gadget
*gadget
);
788 int usb_otg_descriptor_init(struct usb_gadget
*gadget
,
789 struct usb_descriptor_header
*otg_desc
);
790 /*-------------------------------------------------------------------------*/
792 /* utility to simplify map/unmap of usb_requests to/from DMA */
794 extern int usb_gadget_map_request_by_dev(struct device
*dev
,
795 struct usb_request
*req
, int is_in
);
796 extern int usb_gadget_map_request(struct usb_gadget
*gadget
,
797 struct usb_request
*req
, int is_in
);
799 extern void usb_gadget_unmap_request_by_dev(struct device
*dev
,
800 struct usb_request
*req
, int is_in
);
801 extern void usb_gadget_unmap_request(struct usb_gadget
*gadget
,
802 struct usb_request
*req
, int is_in
);
804 /*-------------------------------------------------------------------------*/
806 /* utility to set gadget state properly */
808 extern void usb_gadget_set_state(struct usb_gadget
*gadget
,
809 enum usb_device_state state
);
811 /*-------------------------------------------------------------------------*/
813 /* utility to tell udc core that the bus reset occurs */
814 extern void usb_gadget_udc_reset(struct usb_gadget
*gadget
,
815 struct usb_gadget_driver
*driver
);
817 /*-------------------------------------------------------------------------*/
819 /* utility to give requests back to the gadget layer */
821 extern void usb_gadget_giveback_request(struct usb_ep
*ep
,
822 struct usb_request
*req
);
824 /*-------------------------------------------------------------------------*/
826 /* utility to find endpoint by name */
828 extern struct usb_ep
*gadget_find_ep_by_name(struct usb_gadget
*g
,
831 /*-------------------------------------------------------------------------*/
833 /* utility to check if endpoint caps match descriptor needs */
835 extern int usb_gadget_ep_match_desc(struct usb_gadget
*gadget
,
836 struct usb_ep
*ep
, struct usb_endpoint_descriptor
*desc
,
837 struct usb_ss_ep_comp_descriptor
*ep_comp
);
839 /*-------------------------------------------------------------------------*/
841 /* utility to update vbus status for udc core, it may be scheduled */
842 extern void usb_udc_vbus_handler(struct usb_gadget
*gadget
, bool status
);
844 /*-------------------------------------------------------------------------*/
846 /* utility wrapping a simple endpoint selection policy */
848 extern struct usb_ep
*usb_ep_autoconfig(struct usb_gadget
*,
849 struct usb_endpoint_descriptor
*);
852 extern struct usb_ep
*usb_ep_autoconfig_ss(struct usb_gadget
*,
853 struct usb_endpoint_descriptor
*,
854 struct usb_ss_ep_comp_descriptor
*);
856 extern void usb_ep_autoconfig_release(struct usb_ep
*);
858 extern void usb_ep_autoconfig_reset(struct usb_gadget
*);
860 #endif /* __LINUX_USB_GADGET_H */