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>
31 * struct usb_request - describes one i/o request
32 * @buf: Buffer used for data. Always provide this; some controllers
33 * only use PIO, or don't use DMA for some endpoints.
34 * @dma: DMA address corresponding to 'buf'. If you don't set this
35 * field, and the usb controller needs one, it is responsible
36 * for mapping and unmapping the buffer.
37 * @sg: a scatterlist for SG-capable controllers.
38 * @num_sgs: number of SG entries
39 * @num_mapped_sgs: number of SG entries mapped to DMA (internal)
40 * @length: Length of that data
41 * @stream_id: The stream id, when USB3.0 bulk streams are being used
42 * @no_interrupt: If true, hints that no completion irq is needed.
43 * Helpful sometimes with deep request queues that are handled
44 * directly by DMA controllers.
45 * @zero: If true, when writing data, makes the last packet be "short"
46 * by adding a zero length packet as needed;
47 * @short_not_ok: When reading data, makes short packets be
48 * treated as errors (queue stops advancing till cleanup).
49 * @complete: Function called when request completes, so this request and
50 * its buffer may be re-used. The function will always be called with
51 * interrupts disabled, and it must not sleep.
52 * Reads terminate with a short packet, or when the buffer fills,
53 * whichever comes first. When writes terminate, some data bytes
54 * will usually still be in flight (often in a hardware fifo).
55 * Errors (for reads or writes) stop the queue from advancing
56 * until the completion function returns, so that any transfers
57 * invalidated by the error may first be dequeued.
58 * @context: For use by the completion callback
59 * @list: For use by the gadget driver.
60 * @status: Reports completion code, zero or a negative errno.
61 * Normally, faults block the transfer queue from advancing until
62 * the completion callback returns.
63 * Code "-ESHUTDOWN" indicates completion caused by device disconnect,
64 * or when the driver disabled the endpoint.
65 * @actual: Reports bytes transferred to/from the buffer. For reads (OUT
66 * transfers) this may be less than the requested length. If the
67 * short_not_ok flag is set, short reads are treated as errors
68 * even when status otherwise indicates successful completion.
69 * Note that for writes (IN transfers) some data bytes may still
70 * reside in a device-side FIFO when the request is reported as
73 * These are allocated/freed through the endpoint they're used with. The
74 * hardware's driver can add extra per-request data to the memory it returns,
75 * which often avoids separate memory allocations (potential failures),
76 * later when the request is queued.
78 * Request flags affect request handling, such as whether a zero length
79 * packet is written (the "zero" flag), whether a short read should be
80 * treated as an error (blocking request queue advance, the "short_not_ok"
81 * flag), or hinting that an interrupt is not required (the "no_interrupt"
82 * flag, for use with deep request queues).
84 * Bulk endpoints can use any size buffers, and can also be used for interrupt
85 * transfers. interrupt-only endpoints can be much less functional.
87 * NOTE: this is analogous to 'struct urb' on the host side, except that
88 * it's thinner and promotes more pre-allocation.
96 struct scatterlist *sg;
98 unsigned num_mapped_sgs;
100 unsigned stream_id:16;
101 unsigned no_interrupt:1;
103 unsigned short_not_ok:1;
105 void (*complete)(struct usb_ep *ep,
106 struct usb_request *req);
108 struct list_head list;
114 /*-------------------------------------------------------------------------*/
116 /* endpoint-specific parts of the api to the usb controller hardware.
117 * unlike the urb model, (de)multiplexing layers are not required.
118 * (so this api could slash overhead if used on the host side...)
120 * note that device side usb controllers commonly differ in how many
121 * endpoints they support, as well as their capabilities.
124 int (*enable) (struct usb_ep *ep,
125 const struct usb_endpoint_descriptor *desc);
126 int (*disable) (struct usb_ep *ep);
128 struct usb_request *(*alloc_request) (struct usb_ep *ep,
130 void (*free_request) (struct usb_ep *ep, struct usb_request *req);
132 int (*queue) (struct usb_ep *ep, struct usb_request *req,
134 int (*dequeue) (struct usb_ep *ep, struct usb_request *req);
136 int (*set_halt) (struct usb_ep *ep, int value);
137 int (*set_wedge) (struct usb_ep *ep);
139 int (*fifo_status) (struct usb_ep *ep);
140 void (*fifo_flush) (struct usb_ep *ep);
144 * struct usb_ep_caps - endpoint capabilities description
145 * @type_control:Endpoint supports control type (reserved for ep0).
146 * @type_iso:Endpoint supports isochronous transfers.
147 * @type_bulk:Endpoint supports bulk transfers.
148 * @type_int:Endpoint supports interrupt transfers.
149 * @dir_in:Endpoint supports IN direction.
150 * @dir_out:Endpoint supports OUT direction.
153 unsigned type_control:1;
155 unsigned type_bulk:1;
161 #define USB_EP_CAPS_TYPE_CONTROL 0x01
162 #define USB_EP_CAPS_TYPE_ISO 0x02
163 #define USB_EP_CAPS_TYPE_BULK 0x04
164 #define USB_EP_CAPS_TYPE_INT 0x08
165 #define USB_EP_CAPS_TYPE_ALL \
166 (USB_EP_CAPS_TYPE_ISO | USB_EP_CAPS_TYPE_BULK | USB_EP_CAPS_TYPE_INT)
167 #define USB_EP_CAPS_DIR_IN 0x01
168 #define USB_EP_CAPS_DIR_OUT 0x02
169 #define USB_EP_CAPS_DIR_ALL (USB_EP_CAPS_DIR_IN | USB_EP_CAPS_DIR_OUT)
171 #define USB_EP_CAPS(_type, _dir) \
173 .type_control = !!(_type & USB_EP_CAPS_TYPE_CONTROL), \
174 .type_iso = !!(_type & USB_EP_CAPS_TYPE_ISO), \
175 .type_bulk = !!(_type & USB_EP_CAPS_TYPE_BULK), \
176 .type_int = !!(_type & USB_EP_CAPS_TYPE_INT), \
177 .dir_in = !!(_dir & USB_EP_CAPS_DIR_IN), \
178 .dir_out = !!(_dir & USB_EP_CAPS_DIR_OUT), \
182 * struct usb_ep - device side representation of USB endpoint
183 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk"
184 * @ops: Function pointers used to access hardware-specific operations.
185 * @ep_list:the gadget's ep_list holds all of its endpoints
186 * @caps:The structure describing types and directions supported by endoint.
187 * @maxpacket:The maximum packet size used on this endpoint. The initial
188 * value can sometimes be reduced (hardware allowing), according to
189 * the endpoint descriptor used to configure the endpoint.
190 * @maxpacket_limit:The maximum packet size value which can be handled by this
191 * endpoint. It's set once by UDC driver when endpoint is initialized, and
192 * should not be changed. Should not be confused with maxpacket.
193 * @max_streams: The maximum number of streams supported
194 * by this EP (0 - 16, actual number is 2^n)
195 * @mult: multiplier, 'mult' value for SS Isoc EPs
196 * @maxburst: the maximum number of bursts supported by this EP (for usb3)
197 * @driver_data:for use by the gadget driver.
198 * @address: used to identify the endpoint when finding descriptor that
199 * matches connection speed
200 * @desc: endpoint descriptor. This pointer is set before the endpoint is
201 * enabled and remains valid until the endpoint is disabled.
202 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion
203 * descriptor that is used to configure the endpoint
205 * the bus controller driver lists all the general purpose endpoints in
206 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list,
207 * and is accessed only in response to a driver setup() callback.
214 const struct usb_ep_ops *ops;
215 struct list_head ep_list;
216 struct usb_ep_caps caps;
218 unsigned maxpacket:16;
219 unsigned maxpacket_limit:16;
220 unsigned max_streams:16;
224 const struct usb_endpoint_descriptor *desc;
225 const struct usb_ss_ep_comp_descriptor *comp_desc;
228 /*-------------------------------------------------------------------------*/
231 * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
232 * @ep:the endpoint being configured
233 * @maxpacket_limit:value of maximum packet size limit
235 * This function should be used only in UDC drivers to initialize endpoint
236 * (usually in probe function).
238 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
239 unsigned maxpacket_limit)
241 ep->maxpacket_limit = maxpacket_limit;
242 ep->maxpacket = maxpacket_limit;
246 * usb_ep_enable - configure endpoint, making it usable
247 * @ep:the endpoint being configured. may not be the endpoint named "ep0".
248 * drivers discover endpoints through the ep_list of a usb_gadget.
250 * When configurations are set, or when interface settings change, the driver
251 * will enable or disable the relevant endpoints. while it is enabled, an
252 * endpoint may be used for i/o until the driver receives a disconnect() from
253 * the host or until the endpoint is disabled.
255 * the ep0 implementation (which calls this routine) must ensure that the
256 * hardware capabilities of each endpoint match the descriptor provided
257 * for it. for example, an endpoint named "ep2in-bulk" would be usable
258 * for interrupt transfers as well as bulk, but it likely couldn't be used
259 * for iso transfers or for endpoint 14. some endpoints are fully
260 * configurable, with more generic names like "ep-a". (remember that for
261 * USB, "in" means "towards the USB master".)
263 * returns zero, or a negative error code.
265 static inline int usb_ep_enable(struct usb_ep *ep)
267 return ep->ops->enable(ep, ep->desc);
271 * usb_ep_disable - endpoint is no longer usable
272 * @ep:the endpoint being unconfigured. may not be the endpoint named "ep0".
274 * no other task may be using this endpoint when this is called.
275 * any pending and uncompleted requests will complete with status
276 * indicating disconnect (-ESHUTDOWN) before this call returns.
277 * gadget drivers must call usb_ep_enable() again before queueing
278 * requests to the endpoint.
280 * returns zero, or a negative error code.
282 static inline int usb_ep_disable(struct usb_ep *ep)
284 return ep->ops->disable(ep);
288 * usb_ep_alloc_request - allocate a request object to use with this endpoint
289 * @ep:the endpoint to be used with with the request
290 * @gfp_flags:GFP_* flags to use
292 * Request objects must be allocated with this call, since they normally
293 * need controller-specific setup and may even need endpoint-specific
294 * resources such as allocation of DMA descriptors.
295 * Requests may be submitted with usb_ep_queue(), and receive a single
296 * completion callback. Free requests with usb_ep_free_request(), when
297 * they are no longer needed.
299 * Returns the request, or null if one could not be allocated.
301 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
304 return ep->ops->alloc_request(ep, gfp_flags);
308 * usb_ep_free_request - frees a request object
309 * @ep:the endpoint associated with the request
310 * @req:the request being freed
312 * Reverses the effect of usb_ep_alloc_request().
313 * Caller guarantees the request is not queued, and that it will
314 * no longer be requeued (or otherwise used).
316 static inline void usb_ep_free_request(struct usb_ep *ep,
317 struct usb_request *req)
319 ep->ops->free_request(ep, req);
323 * usb_ep_queue - queues (submits) an I/O request to an endpoint.
324 * @ep:the endpoint associated with the request
325 * @req:the request being submitted
326 * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
327 * pre-allocate all necessary memory with the request.
329 * This tells the device controller to perform the specified request through
330 * that endpoint (reading or writing a buffer). When the request completes,
331 * including being canceled by usb_ep_dequeue(), the request's completion
332 * routine is called to return the request to the driver. Any endpoint
333 * (except control endpoints like ep0) may have more than one transfer
334 * request queued; they complete in FIFO order. Once a gadget driver
335 * submits a request, that request may not be examined or modified until it
336 * is given back to that driver through the completion callback.
338 * Each request is turned into one or more packets. The controller driver
339 * never merges adjacent requests into the same packet. OUT transfers
340 * will sometimes use data that's already buffered in the hardware.
341 * Drivers can rely on the fact that the first byte of the request's buffer
342 * always corresponds to the first byte of some USB packet, for both
343 * IN and OUT transfers.
345 * Bulk endpoints can queue any amount of data; the transfer is packetized
346 * automatically. The last packet will be short if the request doesn't fill it
347 * out completely. Zero length packets (ZLPs) should be avoided in portable
348 * protocols since not all usb hardware can successfully handle zero length
349 * packets. (ZLPs may be explicitly written, and may be implicitly written if
350 * the request 'zero' flag is set.) Bulk endpoints may also be used
351 * for interrupt transfers; but the reverse is not true, and some endpoints
352 * won't support every interrupt transfer. (Such as 768 byte packets.)
354 * Interrupt-only endpoints are less functional than bulk endpoints, for
355 * example by not supporting queueing or not handling buffers that are
356 * larger than the endpoint's maxpacket size. They may also treat data
357 * toggle differently.
359 * Control endpoints ... after getting a setup() callback, the driver queues
360 * one response (even if it would be zero length). That enables the
361 * status ack, after transferring data as specified in the response. Setup
362 * functions may return negative error codes to generate protocol stalls.
363 * (Note that some USB device controllers disallow protocol stall responses
364 * in some cases.) When control responses are deferred (the response is
365 * written after the setup callback returns), then usb_ep_set_halt() may be
366 * used on ep0 to trigger protocol stalls. Depending on the controller,
367 * it may not be possible to trigger a status-stage protocol stall when the
368 * data stage is over, that is, from within the response's completion
371 * For periodic endpoints, like interrupt or isochronous ones, the usb host
372 * arranges to poll once per interval, and the gadget driver usually will
373 * have queued some data to transfer at that time.
375 * Returns zero, or a negative error code. Endpoints that are not enabled
376 * report errors; errors will also be
377 * reported when the usb peripheral is disconnected.
379 static inline int usb_ep_queue(struct usb_ep *ep,
380 struct usb_request *req, gfp_t gfp_flags)
382 return ep->ops->queue(ep, req, gfp_flags);
386 * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
387 * @ep:the endpoint associated with the request
388 * @req:the request being canceled
390 * If the request is still active on the endpoint, it is dequeued and its
391 * completion routine is called (with status -ECONNRESET); else a negative
392 * error code is returned. This is guaranteed to happen before the call to
393 * usb_ep_dequeue() returns.
395 * Note that some hardware can't clear out write fifos (to unlink the request
396 * at the head of the queue) except as part of disconnecting from usb. Such
397 * restrictions prevent drivers from supporting configuration changes,
398 * even to configuration zero (a "chapter 9" requirement).
400 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
402 return ep->ops->dequeue(ep, req);
406 * usb_ep_set_halt - sets the endpoint halt feature.
407 * @ep: the non-isochronous endpoint being stalled
409 * Use this to stall an endpoint, perhaps as an error report.
410 * Except for control endpoints,
411 * the endpoint stays halted (will not stream any data) until the host
412 * clears this feature; drivers may need to empty the endpoint's request
413 * queue first, to make sure no inappropriate transfers happen.
415 * Note that while an endpoint CLEAR_FEATURE will be invisible to the
416 * gadget driver, a SET_INTERFACE will not be. To reset endpoints for the
417 * current altsetting, see usb_ep_clear_halt(). When switching altsettings,
418 * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
420 * Returns zero, or a negative error code. On success, this call sets
421 * underlying hardware state that blocks data transfers.
422 * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
423 * transfer requests are still queued, or if the controller hardware
424 * (usually a FIFO) still holds bytes that the host hasn't collected.
426 static inline int usb_ep_set_halt(struct usb_ep *ep)
428 return ep->ops->set_halt(ep, 1);
432 * usb_ep_clear_halt - clears endpoint halt, and resets toggle
433 * @ep:the bulk or interrupt endpoint being reset
435 * Use this when responding to the standard usb "set interface" request,
436 * for endpoints that aren't reconfigured, after clearing any other state
437 * in the endpoint's i/o queue.
439 * Returns zero, or a negative error code. On success, this call clears
440 * the underlying hardware state reflecting endpoint halt and data toggle.
441 * Note that some hardware can't support this request (like pxa2xx_udc),
442 * and accordingly can't correctly implement interface altsettings.
444 static inline int usb_ep_clear_halt(struct usb_ep *ep)
446 return ep->ops->set_halt(ep, 0);
450 * usb_ep_set_wedge - sets the halt feature and ignores clear requests
451 * @ep: the endpoint being wedged
453 * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT)
454 * requests. If the gadget driver clears the halt status, it will
455 * automatically unwedge the endpoint.
457 * Returns zero on success, else negative errno.
460 usb_ep_set_wedge(struct usb_ep *ep)
462 if (ep->ops->set_wedge)
463 return ep->ops->set_wedge(ep);
465 return ep->ops->set_halt(ep, 1);
469 * usb_ep_fifo_status - returns number of bytes in fifo, or error
470 * @ep: the endpoint whose fifo status is being checked.
472 * FIFO endpoints may have "unclaimed data" in them in certain cases,
473 * such as after aborted transfers. Hosts may not have collected all
474 * the IN data written by the gadget driver (and reported by a request
475 * completion). The gadget driver may not have collected all the data
476 * written OUT to it by the host. Drivers that need precise handling for
477 * fault reporting or recovery may need to use this call.
479 * This returns the number of such bytes in the fifo, or a negative
480 * errno if the endpoint doesn't use a FIFO or doesn't support such
483 static inline int usb_ep_fifo_status(struct usb_ep *ep)
485 if (ep->ops->fifo_status)
486 return ep->ops->fifo_status(ep);
492 * usb_ep_fifo_flush - flushes contents of a fifo
493 * @ep: the endpoint whose fifo is being flushed.
495 * This call may be used to flush the "unclaimed data" that may exist in
496 * an endpoint fifo after abnormal transaction terminations. The call
497 * must never be used except when endpoint is not being used for any
498 * protocol translation.
500 static inline void usb_ep_fifo_flush(struct usb_ep *ep)
502 if (ep->ops->fifo_flush)
503 ep->ops->fifo_flush(ep);
507 /*-------------------------------------------------------------------------*/
509 struct usb_dcd_config_params {
510 __u8 bU1devExitLat; /* U1 Device exit Latency */
511 #define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */
512 __le16 bU2DevExitLat; /* U2 Device exit Latency */
513 #define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */
518 struct usb_gadget_driver;
521 /* the rest of the api to the controller hardware: device operations,
522 * which don't involve endpoints (or i/o).
524 struct usb_gadget_ops {
525 int (*get_frame)(struct usb_gadget *);
526 int (*wakeup)(struct usb_gadget *);
527 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
528 int (*vbus_session) (struct usb_gadget *, int is_active);
529 int (*vbus_draw) (struct usb_gadget *, unsigned mA);
530 int (*pullup) (struct usb_gadget *, int is_on);
531 int (*ioctl)(struct usb_gadget *,
532 unsigned code, unsigned long param);
533 void (*get_config_params)(struct usb_dcd_config_params *);
534 int (*udc_start)(struct usb_gadget *,
535 struct usb_gadget_driver *);
536 int (*udc_stop)(struct usb_gadget *);
537 struct usb_ep *(*match_ep)(struct usb_gadget *,
538 struct usb_endpoint_descriptor *,
539 struct usb_ss_ep_comp_descriptor *);
543 * struct usb_gadget - represents a usb slave device
544 * @work: (internal use) Workqueue to be used for sysfs_notify()
545 * @udc: struct usb_udc pointer for this gadget
546 * @ops: Function pointers used to access hardware-specific operations.
547 * @ep0: Endpoint zero, used when reading or writing responses to
548 * driver setup() requests
549 * @ep_list: List of other endpoints supported by the device.
550 * @speed: Speed of current connection to USB host.
551 * @max_speed: Maximal speed the UDC can handle. UDC must support this
552 * and all slower speeds.
553 * @state: the state we are now (attached, suspended, configured, etc)
554 * @name: Identifies the controller hardware type. Used in diagnostics
555 * and sometimes configuration.
556 * @dev: Driver model state for this abstract device.
557 * @out_epnum: last used out ep number
558 * @in_epnum: last used in ep number
559 * @otg_caps: OTG capabilities of this gadget.
560 * @sg_supported: true if we can handle scatter-gather
561 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
562 * gadget driver must provide a USB OTG descriptor.
563 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable
564 * is in the Mini-AB jack, and HNP has been used to switch roles
565 * so that the "A" device currently acts as A-Peripheral, not A-Host.
566 * @a_hnp_support: OTG device feature flag, indicating that the A-Host
567 * supports HNP at this port.
568 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
569 * only supports HNP on a different root port.
570 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
571 * enabled HNP support.
572 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
574 * @is_selfpowered: if the gadget is self-powered.
575 * @deactivated: True if gadget is deactivated - in deactivated state it cannot
577 * @connected: True if gadget is connected.
579 * Gadgets have a mostly-portable "gadget driver" implementing device
580 * functions, handling all usb configurations and interfaces. Gadget
581 * drivers talk to hardware-specific code indirectly, through ops vectors.
582 * That insulates the gadget driver from hardware details, and packages
583 * the hardware endpoints through generic i/o queues. The "usb_gadget"
584 * and "usb_ep" interfaces provide that insulation from the hardware.
586 * Except for the driver data, all fields in this structure are
587 * read-only to the gadget driver. That driver data is part of the
588 * "driver model" infrastructure in 2.6 (and later) kernels, and for
589 * earlier systems is grouped in a similar structure that's not known
590 * to the rest of the kernel.
592 * Values of the three OTG device feature flags are updated before the
593 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
594 * driver suspend() calls. They are valid only when is_otg, and when the
595 * device is acting as a B-Peripheral (so is_a_peripheral is false).
598 struct work_struct work;
600 /* readonly to gadget driver */
601 const struct usb_gadget_ops *ops;
603 struct list_head ep_list; /* of usb_ep */
604 enum usb_device_speed speed;
605 enum usb_device_speed max_speed;
606 enum usb_device_state state;
611 struct usb_otg_caps *otg_caps;
613 unsigned sg_supported:1;
615 unsigned is_a_peripheral:1;
616 unsigned b_hnp_enable:1;
617 unsigned a_hnp_support:1;
618 unsigned a_alt_hnp_support:1;
619 unsigned quirk_ep_out_aligned_size:1;
620 unsigned quirk_altset_not_supp:1;
621 unsigned quirk_stall_not_supp:1;
622 unsigned quirk_zlp_not_supp:1;
623 unsigned is_selfpowered:1;
624 unsigned deactivated:1;
625 unsigned connected:1;
627 #define work_to_gadget(w) (container_of((w), struct usb_gadget, work))
629 static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
630 { dev_set_drvdata(&gadget->dev, data); }
631 static inline void *get_gadget_data(struct usb_gadget *gadget)
632 { return dev_get_drvdata(&gadget->dev); }
633 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
635 return container_of(dev, struct usb_gadget, dev);
638 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
639 #define gadget_for_each_ep(tmp, gadget) \
640 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
643 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget
644 * requires quirk_ep_out_aligned_size, otherwise reguens len.
645 * @g: controller to check for quirk
646 * @ep: the endpoint whose maxpacketsize is used to align @len
647 * @len: buffer size's length to align to @ep's maxpacketsize
649 * This helper is used in case it's required for any reason to check and maybe
650 * align buffer's size to an ep's maxpacketsize.
653 usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len)
655 return !g->quirk_ep_out_aligned_size ? len :
656 round_up(len, (size_t)ep->desc->wMaxPacketSize);
660 * gadget_is_altset_supported - return true iff the hardware supports
662 * @g: controller to check for quirk
664 static inline int gadget_is_altset_supported(struct usb_gadget *g)
666 return !g->quirk_altset_not_supp;
670 * gadget_is_stall_supported - return true iff the hardware supports stalling
671 * @g: controller to check for quirk
673 static inline int gadget_is_stall_supported(struct usb_gadget *g)
675 return !g->quirk_stall_not_supp;
679 * gadget_is_zlp_supported - return true iff the hardware supports zlp
680 * @g: controller to check for quirk
682 static inline int gadget_is_zlp_supported(struct usb_gadget *g)
684 return !g->quirk_zlp_not_supp;
688 * gadget_is_dualspeed - return true iff the hardware handles high speed
689 * @g: controller that might support both high and full speeds
691 static inline int gadget_is_dualspeed(struct usb_gadget *g)
693 return g->max_speed >= USB_SPEED_HIGH;
697 * gadget_is_superspeed() - return true if the hardware handles superspeed
698 * @g: controller that might support superspeed
700 static inline int gadget_is_superspeed(struct usb_gadget *g)
702 return g->max_speed >= USB_SPEED_SUPER;
706 * gadget_is_otg - return true iff the hardware is OTG-ready
707 * @g: controller that might have a Mini-AB connector
709 * This is a runtime test, since kernels with a USB-OTG stack sometimes
710 * run on boards which only have a Mini-B (or Mini-A) connector.
712 static inline int gadget_is_otg(struct usb_gadget *g)
714 #ifdef CONFIG_USB_OTG
722 * usb_gadget_frame_number - returns the current frame number
723 * @gadget: controller that reports the frame number
725 * Returns the usb frame number, normally eleven bits from a SOF packet,
726 * or negative errno if this device doesn't support this capability.
728 static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
730 return gadget->ops->get_frame(gadget);
734 * usb_gadget_wakeup - tries to wake up the host connected to this gadget
735 * @gadget: controller used to wake up the host
737 * Returns zero on success, else negative error code if the hardware
738 * doesn't support such attempts, or its support has not been enabled
739 * by the usb host. Drivers must return device descriptors that report
740 * their ability to support this, or hosts won't enable it.
742 * This may also try to use SRP to wake the host and start enumeration,
743 * even if OTG isn't otherwise in use. OTG devices may also start
744 * remote wakeup even when hosts don't explicitly enable it.
746 static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
748 if (!gadget->ops->wakeup)
750 return gadget->ops->wakeup(gadget);
754 * usb_gadget_set_selfpowered - sets the device selfpowered feature.
755 * @gadget:the device being declared as self-powered
757 * this affects the device status reported by the hardware driver
758 * to reflect that it now has a local power supply.
760 * returns zero on success, else negative errno.
762 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
764 if (!gadget->ops->set_selfpowered)
766 return gadget->ops->set_selfpowered(gadget, 1);
770 * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
771 * @gadget:the device being declared as bus-powered
773 * this affects the device status reported by the hardware driver.
774 * some hardware may not support bus-powered operation, in which
775 * case this feature's value can never change.
777 * returns zero on success, else negative errno.
779 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
781 if (!gadget->ops->set_selfpowered)
783 return gadget->ops->set_selfpowered(gadget, 0);
787 * usb_gadget_vbus_connect - Notify controller that VBUS is powered
788 * @gadget:The device which now has VBUS power.
791 * This call is used by a driver for an external transceiver (or GPIO)
792 * that detects a VBUS power session starting. Common responses include
793 * resuming the controller, activating the D+ (or D-) pullup to let the
794 * host detect that a USB device is attached, and starting to draw power
795 * (8mA or possibly more, especially after SET_CONFIGURATION).
797 * Returns zero on success, else negative errno.
799 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
801 if (!gadget->ops->vbus_session)
803 return gadget->ops->vbus_session(gadget, 1);
807 * usb_gadget_vbus_draw - constrain controller's VBUS power usage
808 * @gadget:The device whose VBUS usage is being described
809 * @mA:How much current to draw, in milliAmperes. This should be twice
810 * the value listed in the configuration descriptor bMaxPower field.
812 * This call is used by gadget drivers during SET_CONFIGURATION calls,
813 * reporting how much power the device may consume. For example, this
814 * could affect how quickly batteries are recharged.
816 * Returns zero on success, else negative errno.
818 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
820 if (!gadget->ops->vbus_draw)
822 return gadget->ops->vbus_draw(gadget, mA);
826 * usb_gadget_vbus_disconnect - notify controller about VBUS session end
827 * @gadget:the device whose VBUS supply is being described
830 * This call is used by a driver for an external transceiver (or GPIO)
831 * that detects a VBUS power session ending. Common responses include
832 * reversing everything done in usb_gadget_vbus_connect().
834 * Returns zero on success, else negative errno.
836 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
838 if (!gadget->ops->vbus_session)
840 return gadget->ops->vbus_session(gadget, 0);
844 * usb_gadget_connect - software-controlled connect to USB host
845 * @gadget:the peripheral being connected
847 * Enables the D+ (or potentially D-) pullup. The host will start
848 * enumerating this gadget when the pullup is active and a VBUS session
849 * is active (the link is powered). This pullup is always enabled unless
850 * usb_gadget_disconnect() has been used to disable it.
852 * Returns zero on success, else negative errno.
854 static inline int usb_gadget_connect(struct usb_gadget *gadget)
858 if (!gadget->ops->pullup)
861 if (gadget->deactivated) {
863 * If gadget is deactivated we only save new state.
864 * Gadget will be connected automatically after activation.
866 gadget->connected = true;
870 ret = gadget->ops->pullup(gadget, 1);
872 gadget->connected = 1;
877 * usb_gadget_disconnect - software-controlled disconnect from USB host
878 * @gadget:the peripheral being disconnected
880 * Disables the D+ (or potentially D-) pullup, which the host may see
881 * as a disconnect (when a VBUS session is active). Not all systems
882 * support software pullup controls.
884 * Returns zero on success, else negative errno.
886 static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
890 if (!gadget->ops->pullup)
893 if (gadget->deactivated) {
895 * If gadget is deactivated we only save new state.
896 * Gadget will stay disconnected after activation.
898 gadget->connected = false;
902 ret = gadget->ops->pullup(gadget, 0);
904 gadget->connected = 0;
909 * usb_gadget_deactivate - deactivate function which is not ready to work
910 * @gadget: the peripheral being deactivated
912 * This routine may be used during the gadget driver bind() call to prevent
913 * the peripheral from ever being visible to the USB host, unless later
914 * usb_gadget_activate() is called. For example, user mode components may
915 * need to be activated before the system can talk to hosts.
917 * Returns zero on success, else negative errno.
919 static inline int usb_gadget_deactivate(struct usb_gadget *gadget)
923 if (gadget->deactivated)
926 if (gadget->connected) {
927 ret = usb_gadget_disconnect(gadget);
931 * If gadget was being connected before deactivation, we want
932 * to reconnect it in usb_gadget_activate().
934 gadget->connected = true;
936 gadget->deactivated = true;
942 * usb_gadget_activate - activate function which is not ready to work
943 * @gadget: the peripheral being activated
945 * This routine activates gadget which was previously deactivated with
946 * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed.
948 * Returns zero on success, else negative errno.
950 static inline int usb_gadget_activate(struct usb_gadget *gadget)
952 if (!gadget->deactivated)
955 gadget->deactivated = false;
958 * If gadget has been connected before deactivation, or became connected
959 * while it was being deactivated, we call usb_gadget_connect().
961 if (gadget->connected)
962 return usb_gadget_connect(gadget);
967 /*-------------------------------------------------------------------------*/
970 * struct usb_gadget_driver - driver for usb 'slave' devices
971 * @function: String describing the gadget's function
972 * @max_speed: Highest speed the driver handles.
973 * @setup: Invoked for ep0 control requests that aren't handled by
974 * the hardware level driver. Most calls must be handled by
975 * the gadget driver, including descriptor and configuration
976 * management. The 16 bit members of the setup data are in
977 * USB byte order. Called in_interrupt; this may not sleep. Driver
978 * queues a response to ep0, or returns negative to stall.
979 * @disconnect: Invoked after all transfers have been stopped,
980 * when the host is disconnected. May be called in_interrupt; this
981 * may not sleep. Some devices can't detect disconnect, so this might
982 * not be called except as part of controller shutdown.
983 * @bind: the driver's bind callback
984 * @unbind: Invoked when the driver is unbound from a gadget,
985 * usually from rmmod (after a disconnect is reported).
986 * Called in a context that permits sleeping.
987 * @suspend: Invoked on USB suspend. May be called in_interrupt.
988 * @resume: Invoked on USB resume. May be called in_interrupt.
989 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers
990 * and should be called in_interrupt.
991 * @driver: Driver model state for this driver.
993 * Devices are disabled till a gadget driver successfully bind()s, which
994 * means the driver will handle setup() requests needed to enumerate (and
995 * meet "chapter 9" requirements) then do some useful work.
997 * If gadget->is_otg is true, the gadget driver must provide an OTG
998 * descriptor during enumeration, or else fail the bind() call. In such
999 * cases, no USB traffic may flow until both bind() returns without
1000 * having called usb_gadget_disconnect(), and the USB host stack has
1003 * Drivers use hardware-specific knowledge to configure the usb hardware.
1004 * endpoint addressing is only one of several hardware characteristics that
1005 * are in descriptors the ep0 implementation returns from setup() calls.
1007 * Except for ep0 implementation, most driver code shouldn't need change to
1008 * run on top of different usb controllers. It'll use endpoints set up by
1009 * that ep0 implementation.
1011 * The usb controller driver handles a few standard usb requests. Those
1012 * include set_address, and feature flags for devices, interfaces, and
1013 * endpoints (the get_status, set_feature, and clear_feature requests).
1015 * Accordingly, the driver's setup() callback must always implement all
1016 * get_descriptor requests, returning at least a device descriptor and
1017 * a configuration descriptor. Drivers must make sure the endpoint
1018 * descriptors match any hardware constraints. Some hardware also constrains
1019 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
1021 * The driver's setup() callback must also implement set_configuration,
1022 * and should also implement set_interface, get_configuration, and
1023 * get_interface. Setting a configuration (or interface) is where
1024 * endpoints should be activated or (config 0) shut down.
1026 * (Note that only the default control endpoint is supported. Neither
1027 * hosts nor devices generally support control traffic except to ep0.)
1029 * Most devices will ignore USB suspend/resume operations, and so will
1030 * not provide those callbacks. However, some may need to change modes
1031 * when the host is not longer directing those activities. For example,
1032 * local controls (buttons, dials, etc) may need to be re-enabled since
1033 * the (remote) host can't do that any longer; or an error state might
1034 * be cleared, to make the device behave identically whether or not
1035 * power is maintained.
1037 struct usb_gadget_driver {
1039 enum usb_device_speed max_speed;
1040 int (*bind)(struct usb_gadget *gadget,
1041 struct usb_gadget_driver *driver);
1042 void (*unbind)(struct usb_gadget *);
1043 int (*setup)(struct usb_gadget *,
1044 const struct usb_ctrlrequest *);
1045 void (*disconnect)(struct usb_gadget *);
1046 void (*suspend)(struct usb_gadget *);
1047 void (*resume)(struct usb_gadget *);
1048 void (*reset)(struct usb_gadget *);
1050 /* FIXME support safe rmmod */
1051 struct device_driver driver;
1056 /*-------------------------------------------------------------------------*/
1058 /* driver modules register and unregister, as usual.
1059 * these calls must be made in a context that can sleep.
1061 * these will usually be implemented directly by the hardware-dependent
1062 * usb bus interface driver, which will only support a single driver.
1066 * usb_gadget_probe_driver - probe a gadget driver
1067 * @driver: the driver being registered
1068 * Context: can sleep
1070 * Call this in your gadget driver's module initialization function,
1071 * to tell the underlying usb controller driver about your driver.
1072 * The @bind() function will be called to bind it to a gadget before this
1073 * registration call returns. It's expected that the @bind() function will
1074 * be in init sections.
1076 int usb_gadget_probe_driver(struct usb_gadget_driver *driver);
1079 * usb_gadget_unregister_driver - unregister a gadget driver
1080 * @driver:the driver being unregistered
1081 * Context: can sleep
1083 * Call this in your gadget driver's module cleanup function,
1084 * to tell the underlying usb controller that your driver is
1085 * going away. If the controller is connected to a USB host,
1086 * it will first disconnect(). The driver is also requested
1087 * to unbind() and clean up any device state, before this procedure
1088 * finally returns. It's expected that the unbind() functions
1089 * will in in exit sections, so may not be linked in some kernels.
1091 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
1093 extern int usb_add_gadget_udc_release(struct device *parent,
1094 struct usb_gadget *gadget, void (*release)(struct device *dev));
1095 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
1096 extern void usb_del_gadget_udc(struct usb_gadget *gadget);
1097 extern int usb_udc_attach_driver(const char *name,
1098 struct usb_gadget_driver *driver);
1100 /*-------------------------------------------------------------------------*/
1102 /* utility to simplify dealing with string descriptors */
1105 * struct usb_string - wraps a C string and its USB id
1106 * @id:the (nonzero) ID for this string
1107 * @s:the string, in UTF-8 encoding
1109 * If you're using usb_gadget_get_string(), use this to wrap a string
1110 * together with its ID.
1118 * struct usb_gadget_strings - a set of USB strings in a given language
1119 * @language:identifies the strings' language (0x0409 for en-us)
1120 * @strings:array of strings with their ids
1122 * If you're using usb_gadget_get_string(), use this to wrap all the
1123 * strings for a given language.
1125 struct usb_gadget_strings {
1126 u16 language; /* 0x0409 for en-us */
1127 struct usb_string *strings;
1130 struct usb_gadget_string_container {
1131 struct list_head list;
1135 /* put descriptor for string with that id into buf (buflen >= 256) */
1136 int usb_gadget_get_string(struct usb_gadget_strings *table, int id, u8 *buf);
1138 /*-------------------------------------------------------------------------*/
1140 /* utility to simplify managing config descriptors */
1142 /* write vector of descriptors into buffer */
1143 int usb_descriptor_fillbuf(void *, unsigned,
1144 const struct usb_descriptor_header **);
1146 /* build config descriptor from single descriptor vector */
1147 int usb_gadget_config_buf(const struct usb_config_descriptor *config,
1148 void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
1150 /* copy a NULL-terminated vector of descriptors */
1151 struct usb_descriptor_header **usb_copy_descriptors(
1152 struct usb_descriptor_header **);
1155 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors()
1156 * @v: vector of descriptors
1158 static inline void usb_free_descriptors(struct usb_descriptor_header **v)
1163 struct usb_function;
1164 int usb_assign_descriptors(struct usb_function *f,
1165 struct usb_descriptor_header **fs,
1166 struct usb_descriptor_header **hs,
1167 struct usb_descriptor_header **ss);
1168 void usb_free_all_descriptors(struct usb_function *f);
1170 struct usb_descriptor_header *usb_otg_descriptor_alloc(
1171 struct usb_gadget *gadget);
1172 int usb_otg_descriptor_init(struct usb_gadget *gadget,
1173 struct usb_descriptor_header *otg_desc);
1174 /*-------------------------------------------------------------------------*/
1176 /* utility to simplify map/unmap of usb_requests to/from DMA */
1178 extern int usb_gadget_map_request(struct usb_gadget *gadget,
1179 struct usb_request *req, int is_in);
1181 extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
1182 struct usb_request *req, int is_in);
1184 /*-------------------------------------------------------------------------*/
1186 /* utility to set gadget state properly */
1188 extern void usb_gadget_set_state(struct usb_gadget *gadget,
1189 enum usb_device_state state);
1191 /*-------------------------------------------------------------------------*/
1193 /* utility to tell udc core that the bus reset occurs */
1194 extern void usb_gadget_udc_reset(struct usb_gadget *gadget,
1195 struct usb_gadget_driver *driver);
1197 /*-------------------------------------------------------------------------*/
1199 /* utility to give requests back to the gadget layer */
1201 extern void usb_gadget_giveback_request(struct usb_ep *ep,
1202 struct usb_request *req);
1204 /*-------------------------------------------------------------------------*/
1206 /* utility to find endpoint by name */
1208 extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g,
1211 /*-------------------------------------------------------------------------*/
1213 /* utility to check if endpoint caps match descriptor needs */
1215 extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
1216 struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
1217 struct usb_ss_ep_comp_descriptor *ep_comp);
1219 /*-------------------------------------------------------------------------*/
1221 /* utility to update vbus status for udc core, it may be scheduled */
1222 extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status);
1224 /*-------------------------------------------------------------------------*/
1226 /* utility wrapping a simple endpoint selection policy */
1228 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
1229 struct usb_endpoint_descriptor *);
1232 extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *,
1233 struct usb_endpoint_descriptor *,
1234 struct usb_ss_ep_comp_descriptor *);
1236 extern void usb_ep_autoconfig_reset(struct usb_gadget *);
1238 #endif /* __LINUX_USB_GADGET_H */