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TOMOYO Linux Cross Reference
Linux/include/linux/usb/gadget.h

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  1 /*
  2  * <linux/usb/gadget.h>
  3  *
  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.
  7  *
  8  *
  9  * (C) Copyright 2002-2004 by David Brownell
 10  * All Rights Reserved.
 11  *
 12  * This software is licensed under the GNU GPL version 2.
 13  */
 14 
 15 #ifndef __LINUX_USB_GADGET_H
 16 #define __LINUX_USB_GADGET_H
 17 
 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/usb/ch9.h>
 26 
 27 struct usb_ep;
 28 
 29 /**
 30  * struct usb_request - describes one i/o request
 31  * @buf: Buffer used for data.  Always provide this; some controllers
 32  *      only use PIO, or don't use DMA for some endpoints.
 33  * @dma: DMA address corresponding to 'buf'.  If you don't set this
 34  *      field, and the usb controller needs one, it is responsible
 35  *      for mapping and unmapping the buffer.
 36  * @sg: a scatterlist for SG-capable controllers.
 37  * @num_sgs: number of SG entries
 38  * @num_mapped_sgs: number of SG entries mapped to DMA (internal)
 39  * @length: Length of that data
 40  * @stream_id: The stream id, when USB3.0 bulk streams are being used
 41  * @no_interrupt: If true, hints that no completion irq is needed.
 42  *      Helpful sometimes with deep request queues that are handled
 43  *      directly by DMA controllers.
 44  * @zero: If true, when writing data, makes the last packet be "short"
 45  *     by adding a zero length packet as needed;
 46  * @short_not_ok: When reading data, makes short packets be
 47  *     treated as errors (queue stops advancing till cleanup).
 48  * @complete: Function called when request completes, so this request and
 49  *      its buffer may be re-used.  The function will always be called with
 50  *      interrupts disabled, and it must not sleep.
 51  *      Reads terminate with a short packet, or when the buffer fills,
 52  *      whichever comes first.  When writes terminate, some data bytes
 53  *      will usually still be in flight (often in a hardware fifo).
 54  *      Errors (for reads or writes) stop the queue from advancing
 55  *      until the completion function returns, so that any transfers
 56  *      invalidated by the error may first be dequeued.
 57  * @context: For use by the completion callback
 58  * @list: For use by the gadget driver.
 59  * @status: Reports completion code, zero or a negative errno.
 60  *      Normally, faults block the transfer queue from advancing until
 61  *      the completion callback returns.
 62  *      Code "-ESHUTDOWN" indicates completion caused by device disconnect,
 63  *      or when the driver disabled the endpoint.
 64  * @actual: Reports bytes transferred to/from the buffer.  For reads (OUT
 65  *      transfers) this may be less than the requested length.  If the
 66  *      short_not_ok flag is set, short reads are treated as errors
 67  *      even when status otherwise indicates successful completion.
 68  *      Note that for writes (IN transfers) some data bytes may still
 69  *      reside in a device-side FIFO when the request is reported as
 70  *      complete.
 71  *
 72  * These are allocated/freed through the endpoint they're used with.  The
 73  * hardware's driver can add extra per-request data to the memory it returns,
 74  * which often avoids separate memory allocations (potential failures),
 75  * later when the request is queued.
 76  *
 77  * Request flags affect request handling, such as whether a zero length
 78  * packet is written (the "zero" flag), whether a short read should be
 79  * treated as an error (blocking request queue advance, the "short_not_ok"
 80  * flag), or hinting that an interrupt is not required (the "no_interrupt"
 81  * flag, for use with deep request queues).
 82  *
 83  * Bulk endpoints can use any size buffers, and can also be used for interrupt
 84  * transfers. interrupt-only endpoints can be much less functional.
 85  *
 86  * NOTE:  this is analogous to 'struct urb' on the host side, except that
 87  * it's thinner and promotes more pre-allocation.
 88  */
 89 
 90 struct usb_request {
 91         void                    *buf;
 92         unsigned                length;
 93         dma_addr_t              dma;
 94 
 95         struct scatterlist      *sg;
 96         unsigned                num_sgs;
 97         unsigned                num_mapped_sgs;
 98 
 99         unsigned                stream_id:16;
100         unsigned                no_interrupt:1;
101         unsigned                zero:1;
102         unsigned                short_not_ok:1;
103 
104         void                    (*complete)(struct usb_ep *ep,
105                                         struct usb_request *req);
106         void                    *context;
107         struct list_head        list;
108 
109         int                     status;
110         unsigned                actual;
111 };
112 
113 /*-------------------------------------------------------------------------*/
114 
115 /* endpoint-specific parts of the api to the usb controller hardware.
116  * unlike the urb model, (de)multiplexing layers are not required.
117  * (so this api could slash overhead if used on the host side...)
118  *
119  * note that device side usb controllers commonly differ in how many
120  * endpoints they support, as well as their capabilities.
121  */
122 struct usb_ep_ops {
123         int (*enable) (struct usb_ep *ep,
124                 const struct usb_endpoint_descriptor *desc);
125         int (*disable) (struct usb_ep *ep);
126 
127         struct usb_request *(*alloc_request) (struct usb_ep *ep,
128                 gfp_t gfp_flags);
129         void (*free_request) (struct usb_ep *ep, struct usb_request *req);
130 
131         int (*queue) (struct usb_ep *ep, struct usb_request *req,
132                 gfp_t gfp_flags);
133         int (*dequeue) (struct usb_ep *ep, struct usb_request *req);
134 
135         int (*set_halt) (struct usb_ep *ep, int value);
136         int (*set_wedge) (struct usb_ep *ep);
137 
138         int (*fifo_status) (struct usb_ep *ep);
139         void (*fifo_flush) (struct usb_ep *ep);
140 };
141 
142 /**
143  * struct usb_ep - device side representation of USB endpoint
144  * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk"
145  * @ops: Function pointers used to access hardware-specific operations.
146  * @ep_list:the gadget's ep_list holds all of its endpoints
147  * @maxpacket:The maximum packet size used on this endpoint.  The initial
148  *      value can sometimes be reduced (hardware allowing), according to
149  *      the endpoint descriptor used to configure the endpoint.
150  * @max_streams: The maximum number of streams supported
151  *      by this EP (0 - 16, actual number is 2^n)
152  * @mult: multiplier, 'mult' value for SS Isoc EPs
153  * @maxburst: the maximum number of bursts supported by this EP (for usb3)
154  * @driver_data:for use by the gadget driver.
155  * @address: used to identify the endpoint when finding descriptor that
156  *      matches connection speed
157  * @desc: endpoint descriptor.  This pointer is set before the endpoint is
158  *      enabled and remains valid until the endpoint is disabled.
159  * @comp_desc: In case of SuperSpeed support, this is the endpoint companion
160  *      descriptor that is used to configure the endpoint
161  *
162  * the bus controller driver lists all the general purpose endpoints in
163  * gadget->ep_list.  the control endpoint (gadget->ep0) is not in that list,
164  * and is accessed only in response to a driver setup() callback.
165  */
166 struct usb_ep {
167         void                    *driver_data;
168 
169         const char              *name;
170         const struct usb_ep_ops *ops;
171         struct list_head        ep_list;
172         unsigned                maxpacket:16;
173         unsigned                max_streams:16;
174         unsigned                mult:2;
175         unsigned                maxburst:5;
176         u8                      address;
177         const struct usb_endpoint_descriptor    *desc;
178         const struct usb_ss_ep_comp_descriptor  *comp_desc;
179 };
180 
181 /*-------------------------------------------------------------------------*/
182 
183 /**
184  * usb_ep_enable - configure endpoint, making it usable
185  * @ep:the endpoint being configured.  may not be the endpoint named "ep0".
186  *      drivers discover endpoints through the ep_list of a usb_gadget.
187  *
188  * When configurations are set, or when interface settings change, the driver
189  * will enable or disable the relevant endpoints.  while it is enabled, an
190  * endpoint may be used for i/o until the driver receives a disconnect() from
191  * the host or until the endpoint is disabled.
192  *
193  * the ep0 implementation (which calls this routine) must ensure that the
194  * hardware capabilities of each endpoint match the descriptor provided
195  * for it.  for example, an endpoint named "ep2in-bulk" would be usable
196  * for interrupt transfers as well as bulk, but it likely couldn't be used
197  * for iso transfers or for endpoint 14.  some endpoints are fully
198  * configurable, with more generic names like "ep-a".  (remember that for
199  * USB, "in" means "towards the USB master".)
200  *
201  * returns zero, or a negative error code.
202  */
203 static inline int usb_ep_enable(struct usb_ep *ep)
204 {
205         return ep->ops->enable(ep, ep->desc);
206 }
207 
208 /**
209  * usb_ep_disable - endpoint is no longer usable
210  * @ep:the endpoint being unconfigured.  may not be the endpoint named "ep0".
211  *
212  * no other task may be using this endpoint when this is called.
213  * any pending and uncompleted requests will complete with status
214  * indicating disconnect (-ESHUTDOWN) before this call returns.
215  * gadget drivers must call usb_ep_enable() again before queueing
216  * requests to the endpoint.
217  *
218  * returns zero, or a negative error code.
219  */
220 static inline int usb_ep_disable(struct usb_ep *ep)
221 {
222         return ep->ops->disable(ep);
223 }
224 
225 /**
226  * usb_ep_alloc_request - allocate a request object to use with this endpoint
227  * @ep:the endpoint to be used with with the request
228  * @gfp_flags:GFP_* flags to use
229  *
230  * Request objects must be allocated with this call, since they normally
231  * need controller-specific setup and may even need endpoint-specific
232  * resources such as allocation of DMA descriptors.
233  * Requests may be submitted with usb_ep_queue(), and receive a single
234  * completion callback.  Free requests with usb_ep_free_request(), when
235  * they are no longer needed.
236  *
237  * Returns the request, or null if one could not be allocated.
238  */
239 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
240                                                        gfp_t gfp_flags)
241 {
242         return ep->ops->alloc_request(ep, gfp_flags);
243 }
244 
245 /**
246  * usb_ep_free_request - frees a request object
247  * @ep:the endpoint associated with the request
248  * @req:the request being freed
249  *
250  * Reverses the effect of usb_ep_alloc_request().
251  * Caller guarantees the request is not queued, and that it will
252  * no longer be requeued (or otherwise used).
253  */
254 static inline void usb_ep_free_request(struct usb_ep *ep,
255                                        struct usb_request *req)
256 {
257         ep->ops->free_request(ep, req);
258 }
259 
260 /**
261  * usb_ep_queue - queues (submits) an I/O request to an endpoint.
262  * @ep:the endpoint associated with the request
263  * @req:the request being submitted
264  * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
265  *      pre-allocate all necessary memory with the request.
266  *
267  * This tells the device controller to perform the specified request through
268  * that endpoint (reading or writing a buffer).  When the request completes,
269  * including being canceled by usb_ep_dequeue(), the request's completion
270  * routine is called to return the request to the driver.  Any endpoint
271  * (except control endpoints like ep0) may have more than one transfer
272  * request queued; they complete in FIFO order.  Once a gadget driver
273  * submits a request, that request may not be examined or modified until it
274  * is given back to that driver through the completion callback.
275  *
276  * Each request is turned into one or more packets.  The controller driver
277  * never merges adjacent requests into the same packet.  OUT transfers
278  * will sometimes use data that's already buffered in the hardware.
279  * Drivers can rely on the fact that the first byte of the request's buffer
280  * always corresponds to the first byte of some USB packet, for both
281  * IN and OUT transfers.
282  *
283  * Bulk endpoints can queue any amount of data; the transfer is packetized
284  * automatically.  The last packet will be short if the request doesn't fill it
285  * out completely.  Zero length packets (ZLPs) should be avoided in portable
286  * protocols since not all usb hardware can successfully handle zero length
287  * packets.  (ZLPs may be explicitly written, and may be implicitly written if
288  * the request 'zero' flag is set.)  Bulk endpoints may also be used
289  * for interrupt transfers; but the reverse is not true, and some endpoints
290  * won't support every interrupt transfer.  (Such as 768 byte packets.)
291  *
292  * Interrupt-only endpoints are less functional than bulk endpoints, for
293  * example by not supporting queueing or not handling buffers that are
294  * larger than the endpoint's maxpacket size.  They may also treat data
295  * toggle differently.
296  *
297  * Control endpoints ... after getting a setup() callback, the driver queues
298  * one response (even if it would be zero length).  That enables the
299  * status ack, after transferring data as specified in the response.  Setup
300  * functions may return negative error codes to generate protocol stalls.
301  * (Note that some USB device controllers disallow protocol stall responses
302  * in some cases.)  When control responses are deferred (the response is
303  * written after the setup callback returns), then usb_ep_set_halt() may be
304  * used on ep0 to trigger protocol stalls.  Depending on the controller,
305  * it may not be possible to trigger a status-stage protocol stall when the
306  * data stage is over, that is, from within the response's completion
307  * routine.
308  *
309  * For periodic endpoints, like interrupt or isochronous ones, the usb host
310  * arranges to poll once per interval, and the gadget driver usually will
311  * have queued some data to transfer at that time.
312  *
313  * Returns zero, or a negative error code.  Endpoints that are not enabled
314  * report errors; errors will also be
315  * reported when the usb peripheral is disconnected.
316  */
317 static inline int usb_ep_queue(struct usb_ep *ep,
318                                struct usb_request *req, gfp_t gfp_flags)
319 {
320         return ep->ops->queue(ep, req, gfp_flags);
321 }
322 
323 /**
324  * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
325  * @ep:the endpoint associated with the request
326  * @req:the request being canceled
327  *
328  * if the request is still active on the endpoint, it is dequeued and its
329  * completion routine is called (with status -ECONNRESET); else a negative
330  * error code is returned.
331  *
332  * note that some hardware can't clear out write fifos (to unlink the request
333  * at the head of the queue) except as part of disconnecting from usb.  such
334  * restrictions prevent drivers from supporting configuration changes,
335  * even to configuration zero (a "chapter 9" requirement).
336  */
337 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
338 {
339         return ep->ops->dequeue(ep, req);
340 }
341 
342 /**
343  * usb_ep_set_halt - sets the endpoint halt feature.
344  * @ep: the non-isochronous endpoint being stalled
345  *
346  * Use this to stall an endpoint, perhaps as an error report.
347  * Except for control endpoints,
348  * the endpoint stays halted (will not stream any data) until the host
349  * clears this feature; drivers may need to empty the endpoint's request
350  * queue first, to make sure no inappropriate transfers happen.
351  *
352  * Note that while an endpoint CLEAR_FEATURE will be invisible to the
353  * gadget driver, a SET_INTERFACE will not be.  To reset endpoints for the
354  * current altsetting, see usb_ep_clear_halt().  When switching altsettings,
355  * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
356  *
357  * Returns zero, or a negative error code.  On success, this call sets
358  * underlying hardware state that blocks data transfers.
359  * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
360  * transfer requests are still queued, or if the controller hardware
361  * (usually a FIFO) still holds bytes that the host hasn't collected.
362  */
363 static inline int usb_ep_set_halt(struct usb_ep *ep)
364 {
365         return ep->ops->set_halt(ep, 1);
366 }
367 
368 /**
369  * usb_ep_clear_halt - clears endpoint halt, and resets toggle
370  * @ep:the bulk or interrupt endpoint being reset
371  *
372  * Use this when responding to the standard usb "set interface" request,
373  * for endpoints that aren't reconfigured, after clearing any other state
374  * in the endpoint's i/o queue.
375  *
376  * Returns zero, or a negative error code.  On success, this call clears
377  * the underlying hardware state reflecting endpoint halt and data toggle.
378  * Note that some hardware can't support this request (like pxa2xx_udc),
379  * and accordingly can't correctly implement interface altsettings.
380  */
381 static inline int usb_ep_clear_halt(struct usb_ep *ep)
382 {
383         return ep->ops->set_halt(ep, 0);
384 }
385 
386 /**
387  * usb_ep_set_wedge - sets the halt feature and ignores clear requests
388  * @ep: the endpoint being wedged
389  *
390  * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT)
391  * requests. If the gadget driver clears the halt status, it will
392  * automatically unwedge the endpoint.
393  *
394  * Returns zero on success, else negative errno.
395  */
396 static inline int
397 usb_ep_set_wedge(struct usb_ep *ep)
398 {
399         if (ep->ops->set_wedge)
400                 return ep->ops->set_wedge(ep);
401         else
402                 return ep->ops->set_halt(ep, 1);
403 }
404 
405 /**
406  * usb_ep_fifo_status - returns number of bytes in fifo, or error
407  * @ep: the endpoint whose fifo status is being checked.
408  *
409  * FIFO endpoints may have "unclaimed data" in them in certain cases,
410  * such as after aborted transfers.  Hosts may not have collected all
411  * the IN data written by the gadget driver (and reported by a request
412  * completion).  The gadget driver may not have collected all the data
413  * written OUT to it by the host.  Drivers that need precise handling for
414  * fault reporting or recovery may need to use this call.
415  *
416  * This returns the number of such bytes in the fifo, or a negative
417  * errno if the endpoint doesn't use a FIFO or doesn't support such
418  * precise handling.
419  */
420 static inline int usb_ep_fifo_status(struct usb_ep *ep)
421 {
422         if (ep->ops->fifo_status)
423                 return ep->ops->fifo_status(ep);
424         else
425                 return -EOPNOTSUPP;
426 }
427 
428 /**
429  * usb_ep_fifo_flush - flushes contents of a fifo
430  * @ep: the endpoint whose fifo is being flushed.
431  *
432  * This call may be used to flush the "unclaimed data" that may exist in
433  * an endpoint fifo after abnormal transaction terminations.  The call
434  * must never be used except when endpoint is not being used for any
435  * protocol translation.
436  */
437 static inline void usb_ep_fifo_flush(struct usb_ep *ep)
438 {
439         if (ep->ops->fifo_flush)
440                 ep->ops->fifo_flush(ep);
441 }
442 
443 
444 /*-------------------------------------------------------------------------*/
445 
446 struct usb_dcd_config_params {
447         __u8  bU1devExitLat;    /* U1 Device exit Latency */
448 #define USB_DEFAULT_U1_DEV_EXIT_LAT     0x01    /* Less then 1 microsec */
449         __le16 bU2DevExitLat;   /* U2 Device exit Latency */
450 #define USB_DEFAULT_U2_DEV_EXIT_LAT     0x1F4   /* Less then 500 microsec */
451 };
452 
453 
454 struct usb_gadget;
455 struct usb_gadget_driver;
456 
457 /* the rest of the api to the controller hardware: device operations,
458  * which don't involve endpoints (or i/o).
459  */
460 struct usb_gadget_ops {
461         int     (*get_frame)(struct usb_gadget *);
462         int     (*wakeup)(struct usb_gadget *);
463         int     (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
464         int     (*vbus_session) (struct usb_gadget *, int is_active);
465         int     (*vbus_draw) (struct usb_gadget *, unsigned mA);
466         int     (*pullup) (struct usb_gadget *, int is_on);
467         int     (*ioctl)(struct usb_gadget *,
468                                 unsigned code, unsigned long param);
469         void    (*get_config_params)(struct usb_dcd_config_params *);
470         int     (*udc_start)(struct usb_gadget *,
471                         struct usb_gadget_driver *);
472         int     (*udc_stop)(struct usb_gadget *,
473                         struct usb_gadget_driver *);
474 };
475 
476 /**
477  * struct usb_gadget - represents a usb slave device
478  * @ops: Function pointers used to access hardware-specific operations.
479  * @ep0: Endpoint zero, used when reading or writing responses to
480  *      driver setup() requests
481  * @ep_list: List of other endpoints supported by the device.
482  * @speed: Speed of current connection to USB host.
483  * @max_speed: Maximal speed the UDC can handle.  UDC must support this
484  *      and all slower speeds.
485  * @state: the state we are now (attached, suspended, configured, etc)
486  * @sg_supported: true if we can handle scatter-gather
487  * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
488  *      gadget driver must provide a USB OTG descriptor.
489  * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable
490  *      is in the Mini-AB jack, and HNP has been used to switch roles
491  *      so that the "A" device currently acts as A-Peripheral, not A-Host.
492  * @a_hnp_support: OTG device feature flag, indicating that the A-Host
493  *      supports HNP at this port.
494  * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
495  *      only supports HNP on a different root port.
496  * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
497  *      enabled HNP support.
498  * @name: Identifies the controller hardware type.  Used in diagnostics
499  *      and sometimes configuration.
500  * @dev: Driver model state for this abstract device.
501  * @out_epnum: last used out ep number
502  * @in_epnum: last used in ep number
503  *
504  * Gadgets have a mostly-portable "gadget driver" implementing device
505  * functions, handling all usb configurations and interfaces.  Gadget
506  * drivers talk to hardware-specific code indirectly, through ops vectors.
507  * That insulates the gadget driver from hardware details, and packages
508  * the hardware endpoints through generic i/o queues.  The "usb_gadget"
509  * and "usb_ep" interfaces provide that insulation from the hardware.
510  *
511  * Except for the driver data, all fields in this structure are
512  * read-only to the gadget driver.  That driver data is part of the
513  * "driver model" infrastructure in 2.6 (and later) kernels, and for
514  * earlier systems is grouped in a similar structure that's not known
515  * to the rest of the kernel.
516  *
517  * Values of the three OTG device feature flags are updated before the
518  * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
519  * driver suspend() calls.  They are valid only when is_otg, and when the
520  * device is acting as a B-Peripheral (so is_a_peripheral is false).
521  */
522 struct usb_gadget {
523         /* readonly to gadget driver */
524         const struct usb_gadget_ops     *ops;
525         struct usb_ep                   *ep0;
526         struct list_head                ep_list;        /* of usb_ep */
527         enum usb_device_speed           speed;
528         enum usb_device_speed           max_speed;
529         enum usb_device_state           state;
530         unsigned                        sg_supported:1;
531         unsigned                        is_otg:1;
532         unsigned                        is_a_peripheral:1;
533         unsigned                        b_hnp_enable:1;
534         unsigned                        a_hnp_support:1;
535         unsigned                        a_alt_hnp_support:1;
536         const char                      *name;
537         struct device                   dev;
538         unsigned                        out_epnum;
539         unsigned                        in_epnum;
540 };
541 
542 static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
543         { dev_set_drvdata(&gadget->dev, data); }
544 static inline void *get_gadget_data(struct usb_gadget *gadget)
545         { return dev_get_drvdata(&gadget->dev); }
546 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
547 {
548         return container_of(dev, struct usb_gadget, dev);
549 }
550 
551 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
552 #define gadget_for_each_ep(tmp, gadget) \
553         list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
554 
555 
556 /**
557  * gadget_is_dualspeed - return true iff the hardware handles high speed
558  * @g: controller that might support both high and full speeds
559  */
560 static inline int gadget_is_dualspeed(struct usb_gadget *g)
561 {
562         return g->max_speed >= USB_SPEED_HIGH;
563 }
564 
565 /**
566  * gadget_is_superspeed() - return true if the hardware handles superspeed
567  * @g: controller that might support superspeed
568  */
569 static inline int gadget_is_superspeed(struct usb_gadget *g)
570 {
571         return g->max_speed >= USB_SPEED_SUPER;
572 }
573 
574 /**
575  * gadget_is_otg - return true iff the hardware is OTG-ready
576  * @g: controller that might have a Mini-AB connector
577  *
578  * This is a runtime test, since kernels with a USB-OTG stack sometimes
579  * run on boards which only have a Mini-B (or Mini-A) connector.
580  */
581 static inline int gadget_is_otg(struct usb_gadget *g)
582 {
583 #ifdef CONFIG_USB_OTG
584         return g->is_otg;
585 #else
586         return 0;
587 #endif
588 }
589 
590 /**
591  * usb_gadget_frame_number - returns the current frame number
592  * @gadget: controller that reports the frame number
593  *
594  * Returns the usb frame number, normally eleven bits from a SOF packet,
595  * or negative errno if this device doesn't support this capability.
596  */
597 static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
598 {
599         return gadget->ops->get_frame(gadget);
600 }
601 
602 /**
603  * usb_gadget_wakeup - tries to wake up the host connected to this gadget
604  * @gadget: controller used to wake up the host
605  *
606  * Returns zero on success, else negative error code if the hardware
607  * doesn't support such attempts, or its support has not been enabled
608  * by the usb host.  Drivers must return device descriptors that report
609  * their ability to support this, or hosts won't enable it.
610  *
611  * This may also try to use SRP to wake the host and start enumeration,
612  * even if OTG isn't otherwise in use.  OTG devices may also start
613  * remote wakeup even when hosts don't explicitly enable it.
614  */
615 static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
616 {
617         if (!gadget->ops->wakeup)
618                 return -EOPNOTSUPP;
619         return gadget->ops->wakeup(gadget);
620 }
621 
622 /**
623  * usb_gadget_set_selfpowered - sets the device selfpowered feature.
624  * @gadget:the device being declared as self-powered
625  *
626  * this affects the device status reported by the hardware driver
627  * to reflect that it now has a local power supply.
628  *
629  * returns zero on success, else negative errno.
630  */
631 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
632 {
633         if (!gadget->ops->set_selfpowered)
634                 return -EOPNOTSUPP;
635         return gadget->ops->set_selfpowered(gadget, 1);
636 }
637 
638 /**
639  * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
640  * @gadget:the device being declared as bus-powered
641  *
642  * this affects the device status reported by the hardware driver.
643  * some hardware may not support bus-powered operation, in which
644  * case this feature's value can never change.
645  *
646  * returns zero on success, else negative errno.
647  */
648 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
649 {
650         if (!gadget->ops->set_selfpowered)
651                 return -EOPNOTSUPP;
652         return gadget->ops->set_selfpowered(gadget, 0);
653 }
654 
655 /**
656  * usb_gadget_vbus_connect - Notify controller that VBUS is powered
657  * @gadget:The device which now has VBUS power.
658  * Context: can sleep
659  *
660  * This call is used by a driver for an external transceiver (or GPIO)
661  * that detects a VBUS power session starting.  Common responses include
662  * resuming the controller, activating the D+ (or D-) pullup to let the
663  * host detect that a USB device is attached, and starting to draw power
664  * (8mA or possibly more, especially after SET_CONFIGURATION).
665  *
666  * Returns zero on success, else negative errno.
667  */
668 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
669 {
670         if (!gadget->ops->vbus_session)
671                 return -EOPNOTSUPP;
672         return gadget->ops->vbus_session(gadget, 1);
673 }
674 
675 /**
676  * usb_gadget_vbus_draw - constrain controller's VBUS power usage
677  * @gadget:The device whose VBUS usage is being described
678  * @mA:How much current to draw, in milliAmperes.  This should be twice
679  *      the value listed in the configuration descriptor bMaxPower field.
680  *
681  * This call is used by gadget drivers during SET_CONFIGURATION calls,
682  * reporting how much power the device may consume.  For example, this
683  * could affect how quickly batteries are recharged.
684  *
685  * Returns zero on success, else negative errno.
686  */
687 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
688 {
689         if (!gadget->ops->vbus_draw)
690                 return -EOPNOTSUPP;
691         return gadget->ops->vbus_draw(gadget, mA);
692 }
693 
694 /**
695  * usb_gadget_vbus_disconnect - notify controller about VBUS session end
696  * @gadget:the device whose VBUS supply is being described
697  * Context: can sleep
698  *
699  * This call is used by a driver for an external transceiver (or GPIO)
700  * that detects a VBUS power session ending.  Common responses include
701  * reversing everything done in usb_gadget_vbus_connect().
702  *
703  * Returns zero on success, else negative errno.
704  */
705 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
706 {
707         if (!gadget->ops->vbus_session)
708                 return -EOPNOTSUPP;
709         return gadget->ops->vbus_session(gadget, 0);
710 }
711 
712 /**
713  * usb_gadget_connect - software-controlled connect to USB host
714  * @gadget:the peripheral being connected
715  *
716  * Enables the D+ (or potentially D-) pullup.  The host will start
717  * enumerating this gadget when the pullup is active and a VBUS session
718  * is active (the link is powered).  This pullup is always enabled unless
719  * usb_gadget_disconnect() has been used to disable it.
720  *
721  * Returns zero on success, else negative errno.
722  */
723 static inline int usb_gadget_connect(struct usb_gadget *gadget)
724 {
725         if (!gadget->ops->pullup)
726                 return -EOPNOTSUPP;
727         return gadget->ops->pullup(gadget, 1);
728 }
729 
730 /**
731  * usb_gadget_disconnect - software-controlled disconnect from USB host
732  * @gadget:the peripheral being disconnected
733  *
734  * Disables the D+ (or potentially D-) pullup, which the host may see
735  * as a disconnect (when a VBUS session is active).  Not all systems
736  * support software pullup controls.
737  *
738  * This routine may be used during the gadget driver bind() call to prevent
739  * the peripheral from ever being visible to the USB host, unless later
740  * usb_gadget_connect() is called.  For example, user mode components may
741  * need to be activated before the system can talk to hosts.
742  *
743  * Returns zero on success, else negative errno.
744  */
745 static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
746 {
747         if (!gadget->ops->pullup)
748                 return -EOPNOTSUPP;
749         return gadget->ops->pullup(gadget, 0);
750 }
751 
752 
753 /*-------------------------------------------------------------------------*/
754 
755 /**
756  * struct usb_gadget_driver - driver for usb 'slave' devices
757  * @function: String describing the gadget's function
758  * @max_speed: Highest speed the driver handles.
759  * @setup: Invoked for ep0 control requests that aren't handled by
760  *      the hardware level driver. Most calls must be handled by
761  *      the gadget driver, including descriptor and configuration
762  *      management.  The 16 bit members of the setup data are in
763  *      USB byte order. Called in_interrupt; this may not sleep.  Driver
764  *      queues a response to ep0, or returns negative to stall.
765  * @disconnect: Invoked after all transfers have been stopped,
766  *      when the host is disconnected.  May be called in_interrupt; this
767  *      may not sleep.  Some devices can't detect disconnect, so this might
768  *      not be called except as part of controller shutdown.
769  * @bind: the driver's bind callback
770  * @unbind: Invoked when the driver is unbound from a gadget,
771  *      usually from rmmod (after a disconnect is reported).
772  *      Called in a context that permits sleeping.
773  * @suspend: Invoked on USB suspend.  May be called in_interrupt.
774  * @resume: Invoked on USB resume.  May be called in_interrupt.
775  * @driver: Driver model state for this driver.
776  *
777  * Devices are disabled till a gadget driver successfully bind()s, which
778  * means the driver will handle setup() requests needed to enumerate (and
779  * meet "chapter 9" requirements) then do some useful work.
780  *
781  * If gadget->is_otg is true, the gadget driver must provide an OTG
782  * descriptor during enumeration, or else fail the bind() call.  In such
783  * cases, no USB traffic may flow until both bind() returns without
784  * having called usb_gadget_disconnect(), and the USB host stack has
785  * initialized.
786  *
787  * Drivers use hardware-specific knowledge to configure the usb hardware.
788  * endpoint addressing is only one of several hardware characteristics that
789  * are in descriptors the ep0 implementation returns from setup() calls.
790  *
791  * Except for ep0 implementation, most driver code shouldn't need change to
792  * run on top of different usb controllers.  It'll use endpoints set up by
793  * that ep0 implementation.
794  *
795  * The usb controller driver handles a few standard usb requests.  Those
796  * include set_address, and feature flags for devices, interfaces, and
797  * endpoints (the get_status, set_feature, and clear_feature requests).
798  *
799  * Accordingly, the driver's setup() callback must always implement all
800  * get_descriptor requests, returning at least a device descriptor and
801  * a configuration descriptor.  Drivers must make sure the endpoint
802  * descriptors match any hardware constraints. Some hardware also constrains
803  * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
804  *
805  * The driver's setup() callback must also implement set_configuration,
806  * and should also implement set_interface, get_configuration, and
807  * get_interface.  Setting a configuration (or interface) is where
808  * endpoints should be activated or (config 0) shut down.
809  *
810  * (Note that only the default control endpoint is supported.  Neither
811  * hosts nor devices generally support control traffic except to ep0.)
812  *
813  * Most devices will ignore USB suspend/resume operations, and so will
814  * not provide those callbacks.  However, some may need to change modes
815  * when the host is not longer directing those activities.  For example,
816  * local controls (buttons, dials, etc) may need to be re-enabled since
817  * the (remote) host can't do that any longer; or an error state might
818  * be cleared, to make the device behave identically whether or not
819  * power is maintained.
820  */
821 struct usb_gadget_driver {
822         char                    *function;
823         enum usb_device_speed   max_speed;
824         int                     (*bind)(struct usb_gadget *gadget,
825                                         struct usb_gadget_driver *driver);
826         void                    (*unbind)(struct usb_gadget *);
827         int                     (*setup)(struct usb_gadget *,
828                                         const struct usb_ctrlrequest *);
829         void                    (*disconnect)(struct usb_gadget *);
830         void                    (*suspend)(struct usb_gadget *);
831         void                    (*resume)(struct usb_gadget *);
832 
833         /* FIXME support safe rmmod */
834         struct device_driver    driver;
835 };
836 
837 
838 
839 /*-------------------------------------------------------------------------*/
840 
841 /* driver modules register and unregister, as usual.
842  * these calls must be made in a context that can sleep.
843  *
844  * these will usually be implemented directly by the hardware-dependent
845  * usb bus interface driver, which will only support a single driver.
846  */
847 
848 /**
849  * usb_gadget_probe_driver - probe a gadget driver
850  * @driver: the driver being registered
851  * Context: can sleep
852  *
853  * Call this in your gadget driver's module initialization function,
854  * to tell the underlying usb controller driver about your driver.
855  * The @bind() function will be called to bind it to a gadget before this
856  * registration call returns.  It's expected that the @bind() function will
857  * be in init sections.
858  */
859 int usb_gadget_probe_driver(struct usb_gadget_driver *driver);
860 
861 /**
862  * usb_gadget_unregister_driver - unregister a gadget driver
863  * @driver:the driver being unregistered
864  * Context: can sleep
865  *
866  * Call this in your gadget driver's module cleanup function,
867  * to tell the underlying usb controller that your driver is
868  * going away.  If the controller is connected to a USB host,
869  * it will first disconnect().  The driver is also requested
870  * to unbind() and clean up any device state, before this procedure
871  * finally returns.  It's expected that the unbind() functions
872  * will in in exit sections, so may not be linked in some kernels.
873  */
874 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
875 
876 extern int usb_add_gadget_udc_release(struct device *parent,
877                 struct usb_gadget *gadget, void (*release)(struct device *dev));
878 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
879 extern void usb_del_gadget_udc(struct usb_gadget *gadget);
880 extern int udc_attach_driver(const char *name,
881                 struct usb_gadget_driver *driver);
882 
883 /*-------------------------------------------------------------------------*/
884 
885 /* utility to simplify dealing with string descriptors */
886 
887 /**
888  * struct usb_string - wraps a C string and its USB id
889  * @id:the (nonzero) ID for this string
890  * @s:the string, in UTF-8 encoding
891  *
892  * If you're using usb_gadget_get_string(), use this to wrap a string
893  * together with its ID.
894  */
895 struct usb_string {
896         u8                      id;
897         const char              *s;
898 };
899 
900 /**
901  * struct usb_gadget_strings - a set of USB strings in a given language
902  * @language:identifies the strings' language (0x0409 for en-us)
903  * @strings:array of strings with their ids
904  *
905  * If you're using usb_gadget_get_string(), use this to wrap all the
906  * strings for a given language.
907  */
908 struct usb_gadget_strings {
909         u16                     language;       /* 0x0409 for en-us */
910         struct usb_string       *strings;
911 };
912 
913 struct usb_gadget_string_container {
914         struct list_head        list;
915         u8                      *stash[0];
916 };
917 
918 /* put descriptor for string with that id into buf (buflen >= 256) */
919 int usb_gadget_get_string(struct usb_gadget_strings *table, int id, u8 *buf);
920 
921 /*-------------------------------------------------------------------------*/
922 
923 /* utility to simplify managing config descriptors */
924 
925 /* write vector of descriptors into buffer */
926 int usb_descriptor_fillbuf(void *, unsigned,
927                 const struct usb_descriptor_header **);
928 
929 /* build config descriptor from single descriptor vector */
930 int usb_gadget_config_buf(const struct usb_config_descriptor *config,
931         void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
932 
933 /* copy a NULL-terminated vector of descriptors */
934 struct usb_descriptor_header **usb_copy_descriptors(
935                 struct usb_descriptor_header **);
936 
937 /**
938  * usb_free_descriptors - free descriptors returned by usb_copy_descriptors()
939  * @v: vector of descriptors
940  */
941 static inline void usb_free_descriptors(struct usb_descriptor_header **v)
942 {
943         kfree(v);
944 }
945 
946 struct usb_function;
947 int usb_assign_descriptors(struct usb_function *f,
948                 struct usb_descriptor_header **fs,
949                 struct usb_descriptor_header **hs,
950                 struct usb_descriptor_header **ss);
951 void usb_free_all_descriptors(struct usb_function *f);
952 
953 /*-------------------------------------------------------------------------*/
954 
955 /* utility to simplify map/unmap of usb_requests to/from DMA */
956 
957 extern int usb_gadget_map_request(struct usb_gadget *gadget,
958                 struct usb_request *req, int is_in);
959 
960 extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
961                 struct usb_request *req, int is_in);
962 
963 /*-------------------------------------------------------------------------*/
964 
965 /* utility to set gadget state properly */
966 
967 extern void usb_gadget_set_state(struct usb_gadget *gadget,
968                 enum usb_device_state state);
969 
970 /*-------------------------------------------------------------------------*/
971 
972 /* utility wrapping a simple endpoint selection policy */
973 
974 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
975                         struct usb_endpoint_descriptor *);
976 
977 
978 extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *,
979                         struct usb_endpoint_descriptor *,
980                         struct usb_ss_ep_comp_descriptor *);
981 
982 extern void usb_ep_autoconfig_reset(struct usb_gadget *);
983 
984 #endif /* __LINUX_USB_GADGET_H */
985 

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