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 * @dma_mapped: Indicates if request has been mapped to DMA (internal)
52 * @complete: Function called when request completes, so this request and
53 * its buffer may be re-used. The function will always be called with
54 * interrupts disabled, and it must not sleep.
55 * Reads terminate with a short packet, or when the buffer fills,
56 * whichever comes first. When writes terminate, some data bytes
57 * will usually still be in flight (often in a hardware fifo).
58 * Errors (for reads or writes) stop the queue from advancing
59 * until the completion function returns, so that any transfers
60 * invalidated by the error may first be dequeued.
61 * @context: For use by the completion callback
62 * @list: For use by the gadget driver.
63 * @status: Reports completion code, zero or a negative errno.
64 * Normally, faults block the transfer queue from advancing until
65 * the completion callback returns.
66 * Code "-ESHUTDOWN" indicates completion caused by device disconnect,
67 * or when the driver disabled the endpoint.
68 * @actual: Reports bytes transferred to/from the buffer. For reads (OUT
69 * transfers) this may be less than the requested length. If the
70 * short_not_ok flag is set, short reads are treated as errors
71 * even when status otherwise indicates successful completion.
72 * Note that for writes (IN transfers) some data bytes may still
73 * reside in a device-side FIFO when the request is reported as
76 * These are allocated/freed through the endpoint they're used with. The
77 * hardware's driver can add extra per-request data to the memory it returns,
78 * which often avoids separate memory allocations (potential failures),
79 * later when the request is queued.
81 * Request flags affect request handling, such as whether a zero length
82 * packet is written (the "zero" flag), whether a short read should be
83 * treated as an error (blocking request queue advance, the "short_not_ok"
84 * flag), or hinting that an interrupt is not required (the "no_interrupt"
85 * flag, for use with deep request queues).
87 * Bulk endpoints can use any size buffers, and can also be used for interrupt
88 * transfers. interrupt-only endpoints can be much less functional.
90 * NOTE: this is analogous to 'struct urb' on the host side, except that
91 * it's thinner and promotes more pre-allocation.
99 struct scatterlist *sg;
101 unsigned num_mapped_sgs;
103 unsigned stream_id:16;
104 unsigned no_interrupt:1;
106 unsigned short_not_ok:1;
107 unsigned dma_mapped:1;
109 void (*complete)(struct usb_ep *ep,
110 struct usb_request *req);
112 struct list_head list;
118 /*-------------------------------------------------------------------------*/
120 /* endpoint-specific parts of the api to the usb controller hardware.
121 * unlike the urb model, (de)multiplexing layers are not required.
122 * (so this api could slash overhead if used on the host side...)
124 * note that device side usb controllers commonly differ in how many
125 * endpoints they support, as well as their capabilities.
128 int (*enable) (struct usb_ep *ep,
129 const struct usb_endpoint_descriptor *desc);
130 int (*disable) (struct usb_ep *ep);
132 struct usb_request *(*alloc_request) (struct usb_ep *ep,
134 void (*free_request) (struct usb_ep *ep, struct usb_request *req);
136 int (*queue) (struct usb_ep *ep, struct usb_request *req,
138 int (*dequeue) (struct usb_ep *ep, struct usb_request *req);
140 int (*set_halt) (struct usb_ep *ep, int value);
141 int (*set_wedge) (struct usb_ep *ep);
143 int (*fifo_status) (struct usb_ep *ep);
144 void (*fifo_flush) (struct usb_ep *ep);
148 * struct usb_ep_caps - endpoint capabilities description
149 * @type_control:Endpoint supports control type (reserved for ep0).
150 * @type_iso:Endpoint supports isochronous transfers.
151 * @type_bulk:Endpoint supports bulk transfers.
152 * @type_int:Endpoint supports interrupt transfers.
153 * @dir_in:Endpoint supports IN direction.
154 * @dir_out:Endpoint supports OUT direction.
157 unsigned type_control:1;
159 unsigned type_bulk:1;
165 #define USB_EP_CAPS_TYPE_CONTROL 0x01
166 #define USB_EP_CAPS_TYPE_ISO 0x02
167 #define USB_EP_CAPS_TYPE_BULK 0x04
168 #define USB_EP_CAPS_TYPE_INT 0x08
169 #define USB_EP_CAPS_TYPE_ALL \
170 (USB_EP_CAPS_TYPE_ISO | USB_EP_CAPS_TYPE_BULK | USB_EP_CAPS_TYPE_INT)
171 #define USB_EP_CAPS_DIR_IN 0x01
172 #define USB_EP_CAPS_DIR_OUT 0x02
173 #define USB_EP_CAPS_DIR_ALL (USB_EP_CAPS_DIR_IN | USB_EP_CAPS_DIR_OUT)
175 #define USB_EP_CAPS(_type, _dir) \
177 .type_control = !!(_type & USB_EP_CAPS_TYPE_CONTROL), \
178 .type_iso = !!(_type & USB_EP_CAPS_TYPE_ISO), \
179 .type_bulk = !!(_type & USB_EP_CAPS_TYPE_BULK), \
180 .type_int = !!(_type & USB_EP_CAPS_TYPE_INT), \
181 .dir_in = !!(_dir & USB_EP_CAPS_DIR_IN), \
182 .dir_out = !!(_dir & USB_EP_CAPS_DIR_OUT), \
186 * struct usb_ep - device side representation of USB endpoint
187 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk"
188 * @ops: Function pointers used to access hardware-specific operations.
189 * @ep_list:the gadget's ep_list holds all of its endpoints
190 * @caps:The structure describing types and directions supported by endoint.
191 * @maxpacket:The maximum packet size used on this endpoint. The initial
192 * value can sometimes be reduced (hardware allowing), according to
193 * the endpoint descriptor used to configure the endpoint.
194 * @maxpacket_limit:The maximum packet size value which can be handled by this
195 * endpoint. It's set once by UDC driver when endpoint is initialized, and
196 * should not be changed. Should not be confused with maxpacket.
197 * @max_streams: The maximum number of streams supported
198 * by this EP (0 - 16, actual number is 2^n)
199 * @mult: multiplier, 'mult' value for SS Isoc EPs
200 * @maxburst: the maximum number of bursts supported by this EP (for usb3)
201 * @driver_data:for use by the gadget driver.
202 * @address: used to identify the endpoint when finding descriptor that
203 * matches connection speed
204 * @desc: endpoint descriptor. This pointer is set before the endpoint is
205 * enabled and remains valid until the endpoint is disabled.
206 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion
207 * descriptor that is used to configure the endpoint
209 * the bus controller driver lists all the general purpose endpoints in
210 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list,
211 * and is accessed only in response to a driver setup() callback.
218 const struct usb_ep_ops *ops;
219 struct list_head ep_list;
220 struct usb_ep_caps caps;
223 unsigned maxpacket:16;
224 unsigned maxpacket_limit:16;
225 unsigned max_streams:16;
229 const struct usb_endpoint_descriptor *desc;
230 const struct usb_ss_ep_comp_descriptor *comp_desc;
233 /*-------------------------------------------------------------------------*/
235 #if IS_ENABLED(CONFIG_USB_GADGET)
236 void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit);
237 int usb_ep_enable(struct usb_ep *ep);
238 int usb_ep_disable(struct usb_ep *ep);
239 struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags);
240 void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req);
241 int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags);
242 int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req);
243 int usb_ep_set_halt(struct usb_ep *ep);
244 int usb_ep_clear_halt(struct usb_ep *ep);
245 int usb_ep_set_wedge(struct usb_ep *ep);
246 int usb_ep_fifo_status(struct usb_ep *ep);
247 void usb_ep_fifo_flush(struct usb_ep *ep);
249 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
250 unsigned maxpacket_limit)
252 static inline int usb_ep_enable(struct usb_ep *ep)
254 static inline int usb_ep_disable(struct usb_ep *ep)
256 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
259 static inline void usb_ep_free_request(struct usb_ep *ep,
260 struct usb_request *req)
262 static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req,
265 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
267 static inline int usb_ep_set_halt(struct usb_ep *ep)
269 static inline int usb_ep_clear_halt(struct usb_ep *ep)
271 static inline int usb_ep_set_wedge(struct usb_ep *ep)
273 static inline int usb_ep_fifo_status(struct usb_ep *ep)
275 static inline void usb_ep_fifo_flush(struct usb_ep *ep)
277 #endif /* USB_GADGET */
279 /*-------------------------------------------------------------------------*/
281 struct usb_dcd_config_params {
282 __u8 bU1devExitLat; /* U1 Device exit Latency */
283 #define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */
284 __le16 bU2DevExitLat; /* U2 Device exit Latency */
285 #define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */
290 struct usb_gadget_driver;
293 /* the rest of the api to the controller hardware: device operations,
294 * which don't involve endpoints (or i/o).
296 struct usb_gadget_ops {
297 int (*get_frame)(struct usb_gadget *);
298 int (*wakeup)(struct usb_gadget *);
299 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
300 int (*vbus_session) (struct usb_gadget *, int is_active);
301 int (*vbus_draw) (struct usb_gadget *, unsigned mA);
302 int (*pullup) (struct usb_gadget *, int is_on);
303 int (*ioctl)(struct usb_gadget *,
304 unsigned code, unsigned long param);
305 void (*get_config_params)(struct usb_dcd_config_params *);
306 int (*udc_start)(struct usb_gadget *,
307 struct usb_gadget_driver *);
308 int (*udc_stop)(struct usb_gadget *);
309 struct usb_ep *(*match_ep)(struct usb_gadget *,
310 struct usb_endpoint_descriptor *,
311 struct usb_ss_ep_comp_descriptor *);
315 * struct usb_gadget - represents a usb slave device
316 * @work: (internal use) Workqueue to be used for sysfs_notify()
317 * @udc: struct usb_udc pointer for this gadget
318 * @ops: Function pointers used to access hardware-specific operations.
319 * @ep0: Endpoint zero, used when reading or writing responses to
320 * driver setup() requests
321 * @ep_list: List of other endpoints supported by the device.
322 * @speed: Speed of current connection to USB host.
323 * @max_speed: Maximal speed the UDC can handle. UDC must support this
324 * and all slower speeds.
325 * @state: the state we are now (attached, suspended, configured, etc)
326 * @name: Identifies the controller hardware type. Used in diagnostics
327 * and sometimes configuration.
328 * @dev: Driver model state for this abstract device.
329 * @out_epnum: last used out ep number
330 * @in_epnum: last used in ep number
331 * @mA: last set mA value
332 * @otg_caps: OTG capabilities of this gadget.
333 * @sg_supported: true if we can handle scatter-gather
334 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
335 * gadget driver must provide a USB OTG descriptor.
336 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable
337 * is in the Mini-AB jack, and HNP has been used to switch roles
338 * so that the "A" device currently acts as A-Peripheral, not A-Host.
339 * @a_hnp_support: OTG device feature flag, indicating that the A-Host
340 * supports HNP at this port.
341 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
342 * only supports HNP on a different root port.
343 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
344 * enabled HNP support.
345 * @hnp_polling_support: OTG device feature flag, indicating if the OTG device
346 * in peripheral mode can support HNP polling.
347 * @host_request_flag: OTG device feature flag, indicating if A-Peripheral
348 * or B-Peripheral wants to take host role.
349 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
351 * @quirk_avoids_skb_reserve: udc/platform wants to avoid skb_reserve() in
352 * u_ether.c to improve performance.
353 * @is_selfpowered: if the gadget is self-powered.
354 * @deactivated: True if gadget is deactivated - in deactivated state it cannot
356 * @connected: True if gadget is connected.
358 * Gadgets have a mostly-portable "gadget driver" implementing device
359 * functions, handling all usb configurations and interfaces. Gadget
360 * drivers talk to hardware-specific code indirectly, through ops vectors.
361 * That insulates the gadget driver from hardware details, and packages
362 * the hardware endpoints through generic i/o queues. The "usb_gadget"
363 * and "usb_ep" interfaces provide that insulation from the hardware.
365 * Except for the driver data, all fields in this structure are
366 * read-only to the gadget driver. That driver data is part of the
367 * "driver model" infrastructure in 2.6 (and later) kernels, and for
368 * earlier systems is grouped in a similar structure that's not known
369 * to the rest of the kernel.
371 * Values of the three OTG device feature flags are updated before the
372 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
373 * driver suspend() calls. They are valid only when is_otg, and when the
374 * device is acting as a B-Peripheral (so is_a_peripheral is false).
377 struct work_struct work;
379 /* readonly to gadget driver */
380 const struct usb_gadget_ops *ops;
382 struct list_head ep_list; /* of usb_ep */
383 enum usb_device_speed speed;
384 enum usb_device_speed max_speed;
385 enum usb_device_state state;
391 struct usb_otg_caps *otg_caps;
393 unsigned sg_supported:1;
395 unsigned is_a_peripheral:1;
396 unsigned b_hnp_enable:1;
397 unsigned a_hnp_support:1;
398 unsigned a_alt_hnp_support:1;
399 unsigned hnp_polling_support:1;
400 unsigned host_request_flag:1;
401 unsigned quirk_ep_out_aligned_size:1;
402 unsigned quirk_altset_not_supp:1;
403 unsigned quirk_stall_not_supp:1;
404 unsigned quirk_zlp_not_supp:1;
405 unsigned quirk_avoids_skb_reserve:1;
406 unsigned is_selfpowered:1;
407 unsigned deactivated:1;
408 unsigned connected:1;
410 #define work_to_gadget(w) (container_of((w), struct usb_gadget, work))
412 static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
413 { dev_set_drvdata(&gadget->dev, data); }
414 static inline void *get_gadget_data(struct usb_gadget *gadget)
415 { return dev_get_drvdata(&gadget->dev); }
416 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
418 return container_of(dev, struct usb_gadget, dev);
421 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
422 #define gadget_for_each_ep(tmp, gadget) \
423 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
426 * usb_ep_align - returns @len aligned to ep's maxpacketsize.
427 * @ep: the endpoint whose maxpacketsize is used to align @len
428 * @len: buffer size's length to align to @ep's maxpacketsize
430 * This helper is used to align buffer's size to an ep's maxpacketsize.
432 static inline size_t usb_ep_align(struct usb_ep *ep, size_t len)
434 int max_packet_size = (size_t)usb_endpoint_maxp(ep->desc) & 0x7ff;
436 return round_up(len, max_packet_size);
440 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget
441 * requires quirk_ep_out_aligned_size, otherwise returns len.
442 * @g: controller to check for quirk
443 * @ep: the endpoint whose maxpacketsize is used to align @len
444 * @len: buffer size's length to align to @ep's maxpacketsize
446 * This helper is used in case it's required for any reason to check and maybe
447 * align buffer's size to an ep's maxpacketsize.
450 usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len)
452 return g->quirk_ep_out_aligned_size ? usb_ep_align(ep, len) : len;
456 * gadget_is_altset_supported - return true iff the hardware supports
458 * @g: controller to check for quirk
460 static inline int gadget_is_altset_supported(struct usb_gadget *g)
462 return !g->quirk_altset_not_supp;
466 * gadget_is_stall_supported - return true iff the hardware supports stalling
467 * @g: controller to check for quirk
469 static inline int gadget_is_stall_supported(struct usb_gadget *g)
471 return !g->quirk_stall_not_supp;
475 * gadget_is_zlp_supported - return true iff the hardware supports zlp
476 * @g: controller to check for quirk
478 static inline int gadget_is_zlp_supported(struct usb_gadget *g)
480 return !g->quirk_zlp_not_supp;
484 * gadget_avoids_skb_reserve - return true iff the hardware would like to avoid
485 * skb_reserve to improve performance.
486 * @g: controller to check for quirk
488 static inline int gadget_avoids_skb_reserve(struct usb_gadget *g)
490 return g->quirk_avoids_skb_reserve;
494 * gadget_is_dualspeed - return true iff the hardware handles high speed
495 * @g: controller that might support both high and full speeds
497 static inline int gadget_is_dualspeed(struct usb_gadget *g)
499 return g->max_speed >= USB_SPEED_HIGH;
503 * gadget_is_superspeed() - return true if the hardware handles superspeed
504 * @g: controller that might support superspeed
506 static inline int gadget_is_superspeed(struct usb_gadget *g)
508 return g->max_speed >= USB_SPEED_SUPER;
512 * gadget_is_superspeed_plus() - return true if the hardware handles
514 * @g: controller that might support superspeed plus
516 static inline int gadget_is_superspeed_plus(struct usb_gadget *g)
518 return g->max_speed >= USB_SPEED_SUPER_PLUS;
522 * gadget_is_otg - return true iff the hardware is OTG-ready
523 * @g: controller that might have a Mini-AB connector
525 * This is a runtime test, since kernels with a USB-OTG stack sometimes
526 * run on boards which only have a Mini-B (or Mini-A) connector.
528 static inline int gadget_is_otg(struct usb_gadget *g)
530 #ifdef CONFIG_USB_OTG
537 /*-------------------------------------------------------------------------*/
539 #if IS_ENABLED(CONFIG_USB_GADGET)
540 int usb_gadget_frame_number(struct usb_gadget *gadget);
541 int usb_gadget_wakeup(struct usb_gadget *gadget);
542 int usb_gadget_set_selfpowered(struct usb_gadget *gadget);
543 int usb_gadget_clear_selfpowered(struct usb_gadget *gadget);
544 int usb_gadget_vbus_connect(struct usb_gadget *gadget);
545 int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA);
546 int usb_gadget_vbus_disconnect(struct usb_gadget *gadget);
547 int usb_gadget_connect(struct usb_gadget *gadget);
548 int usb_gadget_disconnect(struct usb_gadget *gadget);
549 int usb_gadget_deactivate(struct usb_gadget *gadget);
550 int usb_gadget_activate(struct usb_gadget *gadget);
552 static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
554 static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
556 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
558 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
560 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
562 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
564 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
566 static inline int usb_gadget_connect(struct usb_gadget *gadget)
568 static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
570 static inline int usb_gadget_deactivate(struct usb_gadget *gadget)
572 static inline int usb_gadget_activate(struct usb_gadget *gadget)
574 #endif /* CONFIG_USB_GADGET */
576 /*-------------------------------------------------------------------------*/
579 * struct usb_gadget_driver - driver for usb 'slave' devices
580 * @function: String describing the gadget's function
581 * @max_speed: Highest speed the driver handles.
582 * @setup: Invoked for ep0 control requests that aren't handled by
583 * the hardware level driver. Most calls must be handled by
584 * the gadget driver, including descriptor and configuration
585 * management. The 16 bit members of the setup data are in
586 * USB byte order. Called in_interrupt; this may not sleep. Driver
587 * queues a response to ep0, or returns negative to stall.
588 * @disconnect: Invoked after all transfers have been stopped,
589 * when the host is disconnected. May be called in_interrupt; this
590 * may not sleep. Some devices can't detect disconnect, so this might
591 * not be called except as part of controller shutdown.
592 * @bind: the driver's bind callback
593 * @unbind: Invoked when the driver is unbound from a gadget,
594 * usually from rmmod (after a disconnect is reported).
595 * Called in a context that permits sleeping.
596 * @suspend: Invoked on USB suspend. May be called in_interrupt.
597 * @resume: Invoked on USB resume. May be called in_interrupt.
598 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers
599 * and should be called in_interrupt.
600 * @driver: Driver model state for this driver.
601 * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL,
602 * this driver will be bound to any available UDC.
603 * @pending: UDC core private data used for deferred probe of this driver.
604 * @match_existing_only: If udc is not found, return an error and don't add this
605 * gadget driver to list of pending driver
607 * Devices are disabled till a gadget driver successfully bind()s, which
608 * means the driver will handle setup() requests needed to enumerate (and
609 * meet "chapter 9" requirements) then do some useful work.
611 * If gadget->is_otg is true, the gadget driver must provide an OTG
612 * descriptor during enumeration, or else fail the bind() call. In such
613 * cases, no USB traffic may flow until both bind() returns without
614 * having called usb_gadget_disconnect(), and the USB host stack has
617 * Drivers use hardware-specific knowledge to configure the usb hardware.
618 * endpoint addressing is only one of several hardware characteristics that
619 * are in descriptors the ep0 implementation returns from setup() calls.
621 * Except for ep0 implementation, most driver code shouldn't need change to
622 * run on top of different usb controllers. It'll use endpoints set up by
623 * that ep0 implementation.
625 * The usb controller driver handles a few standard usb requests. Those
626 * include set_address, and feature flags for devices, interfaces, and
627 * endpoints (the get_status, set_feature, and clear_feature requests).
629 * Accordingly, the driver's setup() callback must always implement all
630 * get_descriptor requests, returning at least a device descriptor and
631 * a configuration descriptor. Drivers must make sure the endpoint
632 * descriptors match any hardware constraints. Some hardware also constrains
633 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
635 * The driver's setup() callback must also implement set_configuration,
636 * and should also implement set_interface, get_configuration, and
637 * get_interface. Setting a configuration (or interface) is where
638 * endpoints should be activated or (config 0) shut down.
640 * (Note that only the default control endpoint is supported. Neither
641 * hosts nor devices generally support control traffic except to ep0.)
643 * Most devices will ignore USB suspend/resume operations, and so will
644 * not provide those callbacks. However, some may need to change modes
645 * when the host is not longer directing those activities. For example,
646 * local controls (buttons, dials, etc) may need to be re-enabled since
647 * the (remote) host can't do that any longer; or an error state might
648 * be cleared, to make the device behave identically whether or not
649 * power is maintained.
651 struct usb_gadget_driver {
653 enum usb_device_speed max_speed;
654 int (*bind)(struct usb_gadget *gadget,
655 struct usb_gadget_driver *driver);
656 void (*unbind)(struct usb_gadget *);
657 int (*setup)(struct usb_gadget *,
658 const struct usb_ctrlrequest *);
659 void (*disconnect)(struct usb_gadget *);
660 void (*suspend)(struct usb_gadget *);
661 void (*resume)(struct usb_gadget *);
662 void (*reset)(struct usb_gadget *);
664 /* FIXME support safe rmmod */
665 struct device_driver driver;
668 struct list_head pending;
669 unsigned match_existing_only:1;
674 /*-------------------------------------------------------------------------*/
676 /* driver modules register and unregister, as usual.
677 * these calls must be made in a context that can sleep.
679 * these will usually be implemented directly by the hardware-dependent
680 * usb bus interface driver, which will only support a single driver.
684 * usb_gadget_probe_driver - probe a gadget driver
685 * @driver: the driver being registered
688 * Call this in your gadget driver's module initialization function,
689 * to tell the underlying usb controller driver about your driver.
690 * The @bind() function will be called to bind it to a gadget before this
691 * registration call returns. It's expected that the @bind() function will
692 * be in init sections.
694 int usb_gadget_probe_driver(struct usb_gadget_driver *driver);
697 * usb_gadget_unregister_driver - unregister a gadget driver
698 * @driver:the driver being unregistered
701 * Call this in your gadget driver's module cleanup function,
702 * to tell the underlying usb controller that your driver is
703 * going away. If the controller is connected to a USB host,
704 * it will first disconnect(). The driver is also requested
705 * to unbind() and clean up any device state, before this procedure
706 * finally returns. It's expected that the unbind() functions
707 * will in in exit sections, so may not be linked in some kernels.
709 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
711 extern int usb_add_gadget_udc_release(struct device *parent,
712 struct usb_gadget *gadget, void (*release)(struct device *dev));
713 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
714 extern void usb_del_gadget_udc(struct usb_gadget *gadget);
715 extern char *usb_get_gadget_udc_name(void);
717 /*-------------------------------------------------------------------------*/
719 /* utility to simplify dealing with string descriptors */
722 * struct usb_string - wraps a C string and its USB id
723 * @id:the (nonzero) ID for this string
724 * @s:the string, in UTF-8 encoding
726 * If you're using usb_gadget_get_string(), use this to wrap a string
727 * together with its ID.
735 * struct usb_gadget_strings - a set of USB strings in a given language
736 * @language:identifies the strings' language (0x0409 for en-us)
737 * @strings:array of strings with their ids
739 * If you're using usb_gadget_get_string(), use this to wrap all the
740 * strings for a given language.
742 struct usb_gadget_strings {
743 u16 language; /* 0x0409 for en-us */
744 struct usb_string *strings;
747 struct usb_gadget_string_container {
748 struct list_head list;
752 /* put descriptor for string with that id into buf (buflen >= 256) */
753 int usb_gadget_get_string(struct usb_gadget_strings *table, int id, u8 *buf);
755 /*-------------------------------------------------------------------------*/
757 /* utility to simplify managing config descriptors */
759 /* write vector of descriptors into buffer */
760 int usb_descriptor_fillbuf(void *, unsigned,
761 const struct usb_descriptor_header **);
763 /* build config descriptor from single descriptor vector */
764 int usb_gadget_config_buf(const struct usb_config_descriptor *config,
765 void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
767 /* copy a NULL-terminated vector of descriptors */
768 struct usb_descriptor_header **usb_copy_descriptors(
769 struct usb_descriptor_header **);
772 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors()
773 * @v: vector of descriptors
775 static inline void usb_free_descriptors(struct usb_descriptor_header **v)
781 int usb_assign_descriptors(struct usb_function *f,
782 struct usb_descriptor_header **fs,
783 struct usb_descriptor_header **hs,
784 struct usb_descriptor_header **ss,
785 struct usb_descriptor_header **ssp);
786 void usb_free_all_descriptors(struct usb_function *f);
788 struct usb_descriptor_header *usb_otg_descriptor_alloc(
789 struct usb_gadget *gadget);
790 int usb_otg_descriptor_init(struct usb_gadget *gadget,
791 struct usb_descriptor_header *otg_desc);
792 /*-------------------------------------------------------------------------*/
794 /* utility to simplify map/unmap of usb_requests to/from DMA */
796 extern int usb_gadget_map_request_by_dev(struct device *dev,
797 struct usb_request *req, int is_in);
798 extern int usb_gadget_map_request(struct usb_gadget *gadget,
799 struct usb_request *req, int is_in);
801 extern void usb_gadget_unmap_request_by_dev(struct device *dev,
802 struct usb_request *req, int is_in);
803 extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
804 struct usb_request *req, int is_in);
806 /*-------------------------------------------------------------------------*/
808 /* utility to set gadget state properly */
810 extern void usb_gadget_set_state(struct usb_gadget *gadget,
811 enum usb_device_state state);
813 /*-------------------------------------------------------------------------*/
815 /* utility to tell udc core that the bus reset occurs */
816 extern void usb_gadget_udc_reset(struct usb_gadget *gadget,
817 struct usb_gadget_driver *driver);
819 /*-------------------------------------------------------------------------*/
821 /* utility to give requests back to the gadget layer */
823 extern void usb_gadget_giveback_request(struct usb_ep *ep,
824 struct usb_request *req);
826 /*-------------------------------------------------------------------------*/
828 /* utility to find endpoint by name */
830 extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g,
833 /*-------------------------------------------------------------------------*/
835 /* utility to check if endpoint caps match descriptor needs */
837 extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
838 struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
839 struct usb_ss_ep_comp_descriptor *ep_comp);
841 /*-------------------------------------------------------------------------*/
843 /* utility to update vbus status for udc core, it may be scheduled */
844 extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status);
846 /*-------------------------------------------------------------------------*/
848 /* utility wrapping a simple endpoint selection policy */
850 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
851 struct usb_endpoint_descriptor *);
854 extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *,
855 struct usb_endpoint_descriptor *,
856 struct usb_ss_ep_comp_descriptor *);
858 extern void usb_ep_autoconfig_release(struct usb_ep *);
860 extern void usb_ep_autoconfig_reset(struct usb_gadget *);
862 #endif /* __LINUX_USB_GADGET_H */