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Linux/include/linux/usb/gadget.h

  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/workqueue.h>
 26 #include <linux/usb/ch9.h>
 27 
 28 struct usb_ep;
 29 
 30 /**
 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
 71  *      complete.
 72  *
 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.
 77  *
 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).
 83  *
 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.
 86  *
 87  * NOTE:  this is analogous to 'struct urb' on the host side, except that
 88  * it's thinner and promotes more pre-allocation.
 89  */
 90 
 91 struct usb_request {
 92         void                    *buf;
 93         unsigned                length;
 94         dma_addr_t              dma;
 95 
 96         struct scatterlist      *sg;
 97         unsigned                num_sgs;
 98         unsigned                num_mapped_sgs;
 99 
100         unsigned                stream_id:16;
101         unsigned                no_interrupt:1;
102         unsigned                zero:1;
103         unsigned                short_not_ok:1;
104 
105         void                    (*complete)(struct usb_ep *ep,
106                                         struct usb_request *req);
107         void                    *context;
108         struct list_head        list;
109 
110         int                     status;
111         unsigned                actual;
112 };
113 
114 /*-------------------------------------------------------------------------*/
115 
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...)
119  *
120  * note that device side usb controllers commonly differ in how many
121  * endpoints they support, as well as their capabilities.
122  */
123 struct usb_ep_ops {
124         int (*enable) (struct usb_ep *ep,
125                 const struct usb_endpoint_descriptor *desc);
126         int (*disable) (struct usb_ep *ep);
127 
128         struct usb_request *(*alloc_request) (struct usb_ep *ep,
129                 gfp_t gfp_flags);
130         void (*free_request) (struct usb_ep *ep, struct usb_request *req);
131 
132         int (*queue) (struct usb_ep *ep, struct usb_request *req,
133                 gfp_t gfp_flags);
134         int (*dequeue) (struct usb_ep *ep, struct usb_request *req);
135 
136         int (*set_halt) (struct usb_ep *ep, int value);
137         int (*set_wedge) (struct usb_ep *ep);
138 
139         int (*fifo_status) (struct usb_ep *ep);
140         void (*fifo_flush) (struct usb_ep *ep);
141 };
142 
143 /**
144  * struct usb_ep - device side representation of USB endpoint
145  * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk"
146  * @ops: Function pointers used to access hardware-specific operations.
147  * @ep_list:the gadget's ep_list holds all of its endpoints
148  * @maxpacket:The maximum packet size used on this endpoint.  The initial
149  *      value can sometimes be reduced (hardware allowing), according to
150  *      the endpoint descriptor used to configure the endpoint.
151  * @maxpacket_limit:The maximum packet size value which can be handled by this
152  *      endpoint. It's set once by UDC driver when endpoint is initialized, and
153  *      should not be changed. Should not be confused with maxpacket.
154  * @max_streams: The maximum number of streams supported
155  *      by this EP (0 - 16, actual number is 2^n)
156  * @mult: multiplier, 'mult' value for SS Isoc EPs
157  * @maxburst: the maximum number of bursts supported by this EP (for usb3)
158  * @driver_data:for use by the gadget driver.
159  * @address: used to identify the endpoint when finding descriptor that
160  *      matches connection speed
161  * @desc: endpoint descriptor.  This pointer is set before the endpoint is
162  *      enabled and remains valid until the endpoint is disabled.
163  * @comp_desc: In case of SuperSpeed support, this is the endpoint companion
164  *      descriptor that is used to configure the endpoint
165  *
166  * the bus controller driver lists all the general purpose endpoints in
167  * gadget->ep_list.  the control endpoint (gadget->ep0) is not in that list,
168  * and is accessed only in response to a driver setup() callback.
169  */
170 struct usb_ep {
171         void                    *driver_data;
172 
173         const char              *name;
174         const struct usb_ep_ops *ops;
175         struct list_head        ep_list;
176         unsigned                maxpacket:16;
177         unsigned                maxpacket_limit:16;
178         unsigned                max_streams:16;
179         unsigned                mult:2;
180         unsigned                maxburst:5;
181         u8                      address;
182         const struct usb_endpoint_descriptor    *desc;
183         const struct usb_ss_ep_comp_descriptor  *comp_desc;
184 };
185 
186 /*-------------------------------------------------------------------------*/
187 
188 /**
189  * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
190  * @ep:the endpoint being configured
191  * @maxpacket_limit:value of maximum packet size limit
192  *
193  * This function shoud be used only in UDC drivers to initialize endpoint
194  * (usually in probe function).
195  */
196 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
197                                               unsigned maxpacket_limit)
198 {
199         ep->maxpacket_limit = maxpacket_limit;
200         ep->maxpacket = maxpacket_limit;
201 }
202 
203 /**
204  * usb_ep_enable - configure endpoint, making it usable
205  * @ep:the endpoint being configured.  may not be the endpoint named "ep0".
206  *      drivers discover endpoints through the ep_list of a usb_gadget.
207  *
208  * When configurations are set, or when interface settings change, the driver
209  * will enable or disable the relevant endpoints.  while it is enabled, an
210  * endpoint may be used for i/o until the driver receives a disconnect() from
211  * the host or until the endpoint is disabled.
212  *
213  * the ep0 implementation (which calls this routine) must ensure that the
214  * hardware capabilities of each endpoint match the descriptor provided
215  * for it.  for example, an endpoint named "ep2in-bulk" would be usable
216  * for interrupt transfers as well as bulk, but it likely couldn't be used
217  * for iso transfers or for endpoint 14.  some endpoints are fully
218  * configurable, with more generic names like "ep-a".  (remember that for
219  * USB, "in" means "towards the USB master".)
220  *
221  * returns zero, or a negative error code.
222  */
223 static inline int usb_ep_enable(struct usb_ep *ep)
224 {
225         return ep->ops->enable(ep, ep->desc);
226 }
227 
228 /**
229  * usb_ep_disable - endpoint is no longer usable
230  * @ep:the endpoint being unconfigured.  may not be the endpoint named "ep0".
231  *
232  * no other task may be using this endpoint when this is called.
233  * any pending and uncompleted requests will complete with status
234  * indicating disconnect (-ESHUTDOWN) before this call returns.
235  * gadget drivers must call usb_ep_enable() again before queueing
236  * requests to the endpoint.
237  *
238  * returns zero, or a negative error code.
239  */
240 static inline int usb_ep_disable(struct usb_ep *ep)
241 {
242         return ep->ops->disable(ep);
243 }
244 
245 /**
246  * usb_ep_alloc_request - allocate a request object to use with this endpoint
247  * @ep:the endpoint to be used with with the request
248  * @gfp_flags:GFP_* flags to use
249  *
250  * Request objects must be allocated with this call, since they normally
251  * need controller-specific setup and may even need endpoint-specific
252  * resources such as allocation of DMA descriptors.
253  * Requests may be submitted with usb_ep_queue(), and receive a single
254  * completion callback.  Free requests with usb_ep_free_request(), when
255  * they are no longer needed.
256  *
257  * Returns the request, or null if one could not be allocated.
258  */
259 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
260                                                        gfp_t gfp_flags)
261 {
262         return ep->ops->alloc_request(ep, gfp_flags);
263 }
264 
265 /**
266  * usb_ep_free_request - frees a request object
267  * @ep:the endpoint associated with the request
268  * @req:the request being freed
269  *
270  * Reverses the effect of usb_ep_alloc_request().
271  * Caller guarantees the request is not queued, and that it will
272  * no longer be requeued (or otherwise used).
273  */
274 static inline void usb_ep_free_request(struct usb_ep *ep,
275                                        struct usb_request *req)
276 {
277         ep->ops->free_request(ep, req);
278 }
279 
280 /**
281  * usb_ep_queue - queues (submits) an I/O request to an endpoint.
282  * @ep:the endpoint associated with the request
283  * @req:the request being submitted
284  * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
285  *      pre-allocate all necessary memory with the request.
286  *
287  * This tells the device controller to perform the specified request through
288  * that endpoint (reading or writing a buffer).  When the request completes,
289  * including being canceled by usb_ep_dequeue(), the request's completion
290  * routine is called to return the request to the driver.  Any endpoint
291  * (except control endpoints like ep0) may have more than one transfer
292  * request queued; they complete in FIFO order.  Once a gadget driver
293  * submits a request, that request may not be examined or modified until it
294  * is given back to that driver through the completion callback.
295  *
296  * Each request is turned into one or more packets.  The controller driver
297  * never merges adjacent requests into the same packet.  OUT transfers
298  * will sometimes use data that's already buffered in the hardware.
299  * Drivers can rely on the fact that the first byte of the request's buffer
300  * always corresponds to the first byte of some USB packet, for both
301  * IN and OUT transfers.
302  *
303  * Bulk endpoints can queue any amount of data; the transfer is packetized
304  * automatically.  The last packet will be short if the request doesn't fill it
305  * out completely.  Zero length packets (ZLPs) should be avoided in portable
306  * protocols since not all usb hardware can successfully handle zero length
307  * packets.  (ZLPs may be explicitly written, and may be implicitly written if
308  * the request 'zero' flag is set.)  Bulk endpoints may also be used
309  * for interrupt transfers; but the reverse is not true, and some endpoints
310  * won't support every interrupt transfer.  (Such as 768 byte packets.)
311  *
312  * Interrupt-only endpoints are less functional than bulk endpoints, for
313  * example by not supporting queueing or not handling buffers that are
314  * larger than the endpoint's maxpacket size.  They may also treat data
315  * toggle differently.
316  *
317  * Control endpoints ... after getting a setup() callback, the driver queues
318  * one response (even if it would be zero length).  That enables the
319  * status ack, after transferring data as specified in the response.  Setup
320  * functions may return negative error codes to generate protocol stalls.
321  * (Note that some USB device controllers disallow protocol stall responses
322  * in some cases.)  When control responses are deferred (the response is
323  * written after the setup callback returns), then usb_ep_set_halt() may be
324  * used on ep0 to trigger protocol stalls.  Depending on the controller,
325  * it may not be possible to trigger a status-stage protocol stall when the
326  * data stage is over, that is, from within the response's completion
327  * routine.
328  *
329  * For periodic endpoints, like interrupt or isochronous ones, the usb host
330  * arranges to poll once per interval, and the gadget driver usually will
331  * have queued some data to transfer at that time.
332  *
333  * Returns zero, or a negative error code.  Endpoints that are not enabled
334  * report errors; errors will also be
335  * reported when the usb peripheral is disconnected.
336  */
337 static inline int usb_ep_queue(struct usb_ep *ep,
338                                struct usb_request *req, gfp_t gfp_flags)
339 {
340         return ep->ops->queue(ep, req, gfp_flags);
341 }
342 
343 /**
344  * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
345  * @ep:the endpoint associated with the request
346  * @req:the request being canceled
347  *
348  * if the request is still active on the endpoint, it is dequeued and its
349  * completion routine is called (with status -ECONNRESET); else a negative
350  * error code is returned.
351  *
352  * note that some hardware can't clear out write fifos (to unlink the request
353  * at the head of the queue) except as part of disconnecting from usb.  such
354  * restrictions prevent drivers from supporting configuration changes,
355  * even to configuration zero (a "chapter 9" requirement).
356  */
357 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
358 {
359         return ep->ops->dequeue(ep, req);
360 }
361 
362 /**
363  * usb_ep_set_halt - sets the endpoint halt feature.
364  * @ep: the non-isochronous endpoint being stalled
365  *
366  * Use this to stall an endpoint, perhaps as an error report.
367  * Except for control endpoints,
368  * the endpoint stays halted (will not stream any data) until the host
369  * clears this feature; drivers may need to empty the endpoint's request
370  * queue first, to make sure no inappropriate transfers happen.
371  *
372  * Note that while an endpoint CLEAR_FEATURE will be invisible to the
373  * gadget driver, a SET_INTERFACE will not be.  To reset endpoints for the
374  * current altsetting, see usb_ep_clear_halt().  When switching altsettings,
375  * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
376  *
377  * Returns zero, or a negative error code.  On success, this call sets
378  * underlying hardware state that blocks data transfers.
379  * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
380  * transfer requests are still queued, or if the controller hardware
381  * (usually a FIFO) still holds bytes that the host hasn't collected.
382  */
383 static inline int usb_ep_set_halt(struct usb_ep *ep)
384 {
385         return ep->ops->set_halt(ep, 1);
386 }
387 
388 /**
389  * usb_ep_clear_halt - clears endpoint halt, and resets toggle
390  * @ep:the bulk or interrupt endpoint being reset
391  *
392  * Use this when responding to the standard usb "set interface" request,
393  * for endpoints that aren't reconfigured, after clearing any other state
394  * in the endpoint's i/o queue.
395  *
396  * Returns zero, or a negative error code.  On success, this call clears
397  * the underlying hardware state reflecting endpoint halt and data toggle.
398  * Note that some hardware can't support this request (like pxa2xx_udc),
399  * and accordingly can't correctly implement interface altsettings.
400  */
401 static inline int usb_ep_clear_halt(struct usb_ep *ep)
402 {
403         return ep->ops->set_halt(ep, 0);
404 }
405 
406 /**
407  * usb_ep_set_wedge - sets the halt feature and ignores clear requests
408  * @ep: the endpoint being wedged
409  *
410  * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT)
411  * requests. If the gadget driver clears the halt status, it will
412  * automatically unwedge the endpoint.
413  *
414  * Returns zero on success, else negative errno.
415  */
416 static inline int
417 usb_ep_set_wedge(struct usb_ep *ep)
418 {
419         if (ep->ops->set_wedge)
420                 return ep->ops->set_wedge(ep);
421         else
422                 return ep->ops->set_halt(ep, 1);
423 }
424 
425 /**
426  * usb_ep_fifo_status - returns number of bytes in fifo, or error
427  * @ep: the endpoint whose fifo status is being checked.
428  *
429  * FIFO endpoints may have "unclaimed data" in them in certain cases,
430  * such as after aborted transfers.  Hosts may not have collected all
431  * the IN data written by the gadget driver (and reported by a request
432  * completion).  The gadget driver may not have collected all the data
433  * written OUT to it by the host.  Drivers that need precise handling for
434  * fault reporting or recovery may need to use this call.
435  *
436  * This returns the number of such bytes in the fifo, or a negative
437  * errno if the endpoint doesn't use a FIFO or doesn't support such
438  * precise handling.
439  */
440 static inline int usb_ep_fifo_status(struct usb_ep *ep)
441 {
442         if (ep->ops->fifo_status)
443                 return ep->ops->fifo_status(ep);
444         else
445                 return -EOPNOTSUPP;
446 }
447 
448 /**
449  * usb_ep_fifo_flush - flushes contents of a fifo
450  * @ep: the endpoint whose fifo is being flushed.
451  *
452  * This call may be used to flush the "unclaimed data" that may exist in
453  * an endpoint fifo after abnormal transaction terminations.  The call
454  * must never be used except when endpoint is not being used for any
455  * protocol translation.
456  */
457 static inline void usb_ep_fifo_flush(struct usb_ep *ep)
458 {
459         if (ep->ops->fifo_flush)
460                 ep->ops->fifo_flush(ep);
461 }
462 
463 
464 /*-------------------------------------------------------------------------*/
465 
466 struct usb_dcd_config_params {
467         __u8  bU1devExitLat;    /* U1 Device exit Latency */
468 #define USB_DEFAULT_U1_DEV_EXIT_LAT     0x01    /* Less then 1 microsec */
469         __le16 bU2DevExitLat;   /* U2 Device exit Latency */
470 #define USB_DEFAULT_U2_DEV_EXIT_LAT     0x1F4   /* Less then 500 microsec */
471 };
472 
473 
474 struct usb_gadget;
475 struct usb_gadget_driver;
476 
477 /* the rest of the api to the controller hardware: device operations,
478  * which don't involve endpoints (or i/o).
479  */
480 struct usb_gadget_ops {
481         int     (*get_frame)(struct usb_gadget *);
482         int     (*wakeup)(struct usb_gadget *);
483         int     (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
484         int     (*vbus_session) (struct usb_gadget *, int is_active);
485         int     (*vbus_draw) (struct usb_gadget *, unsigned mA);
486         int     (*pullup) (struct usb_gadget *, int is_on);
487         int     (*ioctl)(struct usb_gadget *,
488                                 unsigned code, unsigned long param);
489         void    (*get_config_params)(struct usb_dcd_config_params *);
490         int     (*udc_start)(struct usb_gadget *,
491                         struct usb_gadget_driver *);
492         int     (*udc_stop)(struct usb_gadget *,
493                         struct usb_gadget_driver *);
494 };
495 
496 /**
497  * struct usb_gadget - represents a usb slave device
498  * @work: (internal use) Workqueue to be used for sysfs_notify()
499  * @ops: Function pointers used to access hardware-specific operations.
500  * @ep0: Endpoint zero, used when reading or writing responses to
501  *      driver setup() requests
502  * @ep_list: List of other endpoints supported by the device.
503  * @speed: Speed of current connection to USB host.
504  * @max_speed: Maximal speed the UDC can handle.  UDC must support this
505  *      and all slower speeds.
506  * @state: the state we are now (attached, suspended, configured, etc)
507  * @name: Identifies the controller hardware type.  Used in diagnostics
508  *      and sometimes configuration.
509  * @dev: Driver model state for this abstract device.
510  * @out_epnum: last used out ep number
511  * @in_epnum: last used in ep number
512  * @sg_supported: true if we can handle scatter-gather
513  * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
514  *      gadget driver must provide a USB OTG descriptor.
515  * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable
516  *      is in the Mini-AB jack, and HNP has been used to switch roles
517  *      so that the "A" device currently acts as A-Peripheral, not A-Host.
518  * @a_hnp_support: OTG device feature flag, indicating that the A-Host
519  *      supports HNP at this port.
520  * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
521  *      only supports HNP on a different root port.
522  * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
523  *      enabled HNP support.
524  * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
525  *      MaxPacketSize.
526  *
527  * Gadgets have a mostly-portable "gadget driver" implementing device
528  * functions, handling all usb configurations and interfaces.  Gadget
529  * drivers talk to hardware-specific code indirectly, through ops vectors.
530  * That insulates the gadget driver from hardware details, and packages
531  * the hardware endpoints through generic i/o queues.  The "usb_gadget"
532  * and "usb_ep" interfaces provide that insulation from the hardware.
533  *
534  * Except for the driver data, all fields in this structure are
535  * read-only to the gadget driver.  That driver data is part of the
536  * "driver model" infrastructure in 2.6 (and later) kernels, and for
537  * earlier systems is grouped in a similar structure that's not known
538  * to the rest of the kernel.
539  *
540  * Values of the three OTG device feature flags are updated before the
541  * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
542  * driver suspend() calls.  They are valid only when is_otg, and when the
543  * device is acting as a B-Peripheral (so is_a_peripheral is false).
544  */
545 struct usb_gadget {
546         struct work_struct              work;
547         /* readonly to gadget driver */
548         const struct usb_gadget_ops     *ops;
549         struct usb_ep                   *ep0;
550         struct list_head                ep_list;        /* of usb_ep */
551         enum usb_device_speed           speed;
552         enum usb_device_speed           max_speed;
553         enum usb_device_state           state;
554         const char                      *name;
555         struct device                   dev;
556         unsigned                        out_epnum;
557         unsigned                        in_epnum;
558 
559         unsigned                        sg_supported:1;
560         unsigned                        is_otg:1;
561         unsigned                        is_a_peripheral:1;
562         unsigned                        b_hnp_enable:1;
563         unsigned                        a_hnp_support:1;
564         unsigned                        a_alt_hnp_support:1;
565         unsigned                        quirk_ep_out_aligned_size:1;
566 };
567 #define work_to_gadget(w)       (container_of((w), struct usb_gadget, work))
568 
569 static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
570         { dev_set_drvdata(&gadget->dev, data); }
571 static inline void *get_gadget_data(struct usb_gadget *gadget)
572         { return dev_get_drvdata(&gadget->dev); }
573 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
574 {
575         return container_of(dev, struct usb_gadget, dev);
576 }
577 
578 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
579 #define gadget_for_each_ep(tmp, gadget) \
580         list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
581 
582 
583 /**
584  * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget
585  *      requires quirk_ep_out_aligned_size, otherwise reguens len.
586  * @g: controller to check for quirk
587  * @ep: the endpoint whose maxpacketsize is used to align @len
588  * @len: buffer size's length to align to @ep's maxpacketsize
589  *
590  * This helper is used in case it's required for any reason to check and maybe
591  * align buffer's size to an ep's maxpacketsize.
592  */
593 static inline size_t
594 usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len)
595 {
596         return !g->quirk_ep_out_aligned_size ? len :
597                         round_up(len, (size_t)ep->desc->wMaxPacketSize);
598 }
599 
600 /**
601  * gadget_is_dualspeed - return true iff the hardware handles high speed
602  * @g: controller that might support both high and full speeds
603  */
604 static inline int gadget_is_dualspeed(struct usb_gadget *g)
605 {
606         return g->max_speed >= USB_SPEED_HIGH;
607 }
608 
609 /**
610  * gadget_is_superspeed() - return true if the hardware handles superspeed
611  * @g: controller that might support superspeed
612  */
613 static inline int gadget_is_superspeed(struct usb_gadget *g)
614 {
615         return g->max_speed >= USB_SPEED_SUPER;
616 }
617 
618 /**
619  * gadget_is_otg - return true iff the hardware is OTG-ready
620  * @g: controller that might have a Mini-AB connector
621  *
622  * This is a runtime test, since kernels with a USB-OTG stack sometimes
623  * run on boards which only have a Mini-B (or Mini-A) connector.
624  */
625 static inline int gadget_is_otg(struct usb_gadget *g)
626 {
627 #ifdef CONFIG_USB_OTG
628         return g->is_otg;
629 #else
630         return 0;
631 #endif
632 }
633 
634 /**
635  * usb_gadget_frame_number - returns the current frame number
636  * @gadget: controller that reports the frame number
637  *
638  * Returns the usb frame number, normally eleven bits from a SOF packet,
639  * or negative errno if this device doesn't support this capability.
640  */
641 static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
642 {
643         return gadget->ops->get_frame(gadget);
644 }
645 
646 /**
647  * usb_gadget_wakeup - tries to wake up the host connected to this gadget
648  * @gadget: controller used to wake up the host
649  *
650  * Returns zero on success, else negative error code if the hardware
651  * doesn't support such attempts, or its support has not been enabled
652  * by the usb host.  Drivers must return device descriptors that report
653  * their ability to support this, or hosts won't enable it.
654  *
655  * This may also try to use SRP to wake the host and start enumeration,
656  * even if OTG isn't otherwise in use.  OTG devices may also start
657  * remote wakeup even when hosts don't explicitly enable it.
658  */
659 static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
660 {
661         if (!gadget->ops->wakeup)
662                 return -EOPNOTSUPP;
663         return gadget->ops->wakeup(gadget);
664 }
665 
666 /**
667  * usb_gadget_set_selfpowered - sets the device selfpowered feature.
668  * @gadget:the device being declared as self-powered
669  *
670  * this affects the device status reported by the hardware driver
671  * to reflect that it now has a local power supply.
672  *
673  * returns zero on success, else negative errno.
674  */
675 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
676 {
677         if (!gadget->ops->set_selfpowered)
678                 return -EOPNOTSUPP;
679         return gadget->ops->set_selfpowered(gadget, 1);
680 }
681 
682 /**
683  * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
684  * @gadget:the device being declared as bus-powered
685  *
686  * this affects the device status reported by the hardware driver.
687  * some hardware may not support bus-powered operation, in which
688  * case this feature's value can never change.
689  *
690  * returns zero on success, else negative errno.
691  */
692 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
693 {
694         if (!gadget->ops->set_selfpowered)
695                 return -EOPNOTSUPP;
696         return gadget->ops->set_selfpowered(gadget, 0);
697 }
698 
699 /**
700  * usb_gadget_vbus_connect - Notify controller that VBUS is powered
701  * @gadget:The device which now has VBUS power.
702  * Context: can sleep
703  *
704  * This call is used by a driver for an external transceiver (or GPIO)
705  * that detects a VBUS power session starting.  Common responses include
706  * resuming the controller, activating the D+ (or D-) pullup to let the
707  * host detect that a USB device is attached, and starting to draw power
708  * (8mA or possibly more, especially after SET_CONFIGURATION).
709  *
710  * Returns zero on success, else negative errno.
711  */
712 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
713 {
714         if (!gadget->ops->vbus_session)
715                 return -EOPNOTSUPP;
716         return gadget->ops->vbus_session(gadget, 1);
717 }
718 
719 /**
720  * usb_gadget_vbus_draw - constrain controller's VBUS power usage
721  * @gadget:The device whose VBUS usage is being described
722  * @mA:How much current to draw, in milliAmperes.  This should be twice
723  *      the value listed in the configuration descriptor bMaxPower field.
724  *
725  * This call is used by gadget drivers during SET_CONFIGURATION calls,
726  * reporting how much power the device may consume.  For example, this
727  * could affect how quickly batteries are recharged.
728  *
729  * Returns zero on success, else negative errno.
730  */
731 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
732 {
733         if (!gadget->ops->vbus_draw)
734                 return -EOPNOTSUPP;
735         return gadget->ops->vbus_draw(gadget, mA);
736 }
737 
738 /**
739  * usb_gadget_vbus_disconnect - notify controller about VBUS session end
740  * @gadget:the device whose VBUS supply is being described
741  * Context: can sleep
742  *
743  * This call is used by a driver for an external transceiver (or GPIO)
744  * that detects a VBUS power session ending.  Common responses include
745  * reversing everything done in usb_gadget_vbus_connect().
746  *
747  * Returns zero on success, else negative errno.
748  */
749 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
750 {
751         if (!gadget->ops->vbus_session)
752                 return -EOPNOTSUPP;
753         return gadget->ops->vbus_session(gadget, 0);
754 }
755 
756 /**
757  * usb_gadget_connect - software-controlled connect to USB host
758  * @gadget:the peripheral being connected
759  *
760  * Enables the D+ (or potentially D-) pullup.  The host will start
761  * enumerating this gadget when the pullup is active and a VBUS session
762  * is active (the link is powered).  This pullup is always enabled unless
763  * usb_gadget_disconnect() has been used to disable it.
764  *
765  * Returns zero on success, else negative errno.
766  */
767 static inline int usb_gadget_connect(struct usb_gadget *gadget)
768 {
769         if (!gadget->ops->pullup)
770                 return -EOPNOTSUPP;
771         return gadget->ops->pullup(gadget, 1);
772 }
773 
774 /**
775  * usb_gadget_disconnect - software-controlled disconnect from USB host
776  * @gadget:the peripheral being disconnected
777  *
778  * Disables the D+ (or potentially D-) pullup, which the host may see
779  * as a disconnect (when a VBUS session is active).  Not all systems
780  * support software pullup controls.
781  *
782  * This routine may be used during the gadget driver bind() call to prevent
783  * the peripheral from ever being visible to the USB host, unless later
784  * usb_gadget_connect() is called.  For example, user mode components may
785  * need to be activated before the system can talk to hosts.
786  *
787  * Returns zero on success, else negative errno.
788  */
789 static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
790 {
791         if (!gadget->ops->pullup)
792                 return -EOPNOTSUPP;
793         return gadget->ops->pullup(gadget, 0);
794 }
795 
796 
797 /*-------------------------------------------------------------------------*/
798 
799 /**
800  * struct usb_gadget_driver - driver for usb 'slave' devices
801  * @function: String describing the gadget's function
802  * @max_speed: Highest speed the driver handles.
803  * @setup: Invoked for ep0 control requests that aren't handled by
804  *      the hardware level driver. Most calls must be handled by
805  *      the gadget driver, including descriptor and configuration
806  *      management.  The 16 bit members of the setup data are in
807  *      USB byte order. Called in_interrupt; this may not sleep.  Driver
808  *      queues a response to ep0, or returns negative to stall.
809  * @disconnect: Invoked after all transfers have been stopped,
810  *      when the host is disconnected.  May be called in_interrupt; this
811  *      may not sleep.  Some devices can't detect disconnect, so this might
812  *      not be called except as part of controller shutdown.
813  * @bind: the driver's bind callback
814  * @unbind: Invoked when the driver is unbound from a gadget,
815  *      usually from rmmod (after a disconnect is reported).
816  *      Called in a context that permits sleeping.
817  * @suspend: Invoked on USB suspend.  May be called in_interrupt.
818  * @resume: Invoked on USB resume.  May be called in_interrupt.
819  * @driver: Driver model state for this driver.
820  *
821  * Devices are disabled till a gadget driver successfully bind()s, which
822  * means the driver will handle setup() requests needed to enumerate (and
823  * meet "chapter 9" requirements) then do some useful work.
824  *
825  * If gadget->is_otg is true, the gadget driver must provide an OTG
826  * descriptor during enumeration, or else fail the bind() call.  In such
827  * cases, no USB traffic may flow until both bind() returns without
828  * having called usb_gadget_disconnect(), and the USB host stack has
829  * initialized.
830  *
831  * Drivers use hardware-specific knowledge to configure the usb hardware.
832  * endpoint addressing is only one of several hardware characteristics that
833  * are in descriptors the ep0 implementation returns from setup() calls.
834  *
835  * Except for ep0 implementation, most driver code shouldn't need change to
836  * run on top of different usb controllers.  It'll use endpoints set up by
837  * that ep0 implementation.
838  *
839  * The usb controller driver handles a few standard usb requests.  Those
840  * include set_address, and feature flags for devices, interfaces, and
841  * endpoints (the get_status, set_feature, and clear_feature requests).
842  *
843  * Accordingly, the driver's setup() callback must always implement all
844  * get_descriptor requests, returning at least a device descriptor and
845  * a configuration descriptor.  Drivers must make sure the endpoint
846  * descriptors match any hardware constraints. Some hardware also constrains
847  * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
848  *
849  * The driver's setup() callback must also implement set_configuration,
850  * and should also implement set_interface, get_configuration, and
851  * get_interface.  Setting a configuration (or interface) is where
852  * endpoints should be activated or (config 0) shut down.
853  *
854  * (Note that only the default control endpoint is supported.  Neither
855  * hosts nor devices generally support control traffic except to ep0.)
856  *
857  * Most devices will ignore USB suspend/resume operations, and so will
858  * not provide those callbacks.  However, some may need to change modes
859  * when the host is not longer directing those activities.  For example,
860  * local controls (buttons, dials, etc) may need to be re-enabled since
861  * the (remote) host can't do that any longer; or an error state might
862  * be cleared, to make the device behave identically whether or not
863  * power is maintained.
864  */
865 struct usb_gadget_driver {
866         char                    *function;
867         enum usb_device_speed   max_speed;
868         int                     (*bind)(struct usb_gadget *gadget,
869                                         struct usb_gadget_driver *driver);
870         void                    (*unbind)(struct usb_gadget *);
871         int                     (*setup)(struct usb_gadget *,
872                                         const struct usb_ctrlrequest *);
873         void                    (*disconnect)(struct usb_gadget *);
874         void                    (*suspend)(struct usb_gadget *);
875         void                    (*resume)(struct usb_gadget *);
876 
877         /* FIXME support safe rmmod */
878         struct device_driver    driver;
879 };
880 
881 
882 
883 /*-------------------------------------------------------------------------*/
884 
885 /* driver modules register and unregister, as usual.
886  * these calls must be made in a context that can sleep.
887  *
888  * these will usually be implemented directly by the hardware-dependent
889  * usb bus interface driver, which will only support a single driver.
890  */
891 
892 /**
893  * usb_gadget_probe_driver - probe a gadget driver
894  * @driver: the driver being registered
895  * Context: can sleep
896  *
897  * Call this in your gadget driver's module initialization function,
898  * to tell the underlying usb controller driver about your driver.
899  * The @bind() function will be called to bind it to a gadget before this
900  * registration call returns.  It's expected that the @bind() function will
901  * be in init sections.
902  */
903 int usb_gadget_probe_driver(struct usb_gadget_driver *driver);
904 
905 /**
906  * usb_gadget_unregister_driver - unregister a gadget driver
907  * @driver:the driver being unregistered
908  * Context: can sleep
909  *
910  * Call this in your gadget driver's module cleanup function,
911  * to tell the underlying usb controller that your driver is
912  * going away.  If the controller is connected to a USB host,
913  * it will first disconnect().  The driver is also requested
914  * to unbind() and clean up any device state, before this procedure
915  * finally returns.  It's expected that the unbind() functions
916  * will in in exit sections, so may not be linked in some kernels.
917  */
918 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
919 
920 extern int usb_add_gadget_udc_release(struct device *parent,
921                 struct usb_gadget *gadget, void (*release)(struct device *dev));
922 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
923 extern void usb_del_gadget_udc(struct usb_gadget *gadget);
924 extern int udc_attach_driver(const char *name,
925                 struct usb_gadget_driver *driver);
926 
927 /*-------------------------------------------------------------------------*/
928 
929 /* utility to simplify dealing with string descriptors */
930 
931 /**
932  * struct usb_string - wraps a C string and its USB id
933  * @id:the (nonzero) ID for this string
934  * @s:the string, in UTF-8 encoding
935  *
936  * If you're using usb_gadget_get_string(), use this to wrap a string
937  * together with its ID.
938  */
939 struct usb_string {
940         u8                      id;
941         const char              *s;
942 };
943 
944 /**
945  * struct usb_gadget_strings - a set of USB strings in a given language
946  * @language:identifies the strings' language (0x0409 for en-us)
947  * @strings:array of strings with their ids
948  *
949  * If you're using usb_gadget_get_string(), use this to wrap all the
950  * strings for a given language.
951  */
952 struct usb_gadget_strings {
953         u16                     language;       /* 0x0409 for en-us */
954         struct usb_string       *strings;
955 };
956 
957 struct usb_gadget_string_container {
958         struct list_head        list;
959         u8                      *stash[0];
960 };
961 
962 /* put descriptor for string with that id into buf (buflen >= 256) */
963 int usb_gadget_get_string(struct usb_gadget_strings *table, int id, u8 *buf);
964 
965 /*-------------------------------------------------------------------------*/
966 
967 /* utility to simplify managing config descriptors */
968 
969 /* write vector of descriptors into buffer */
970 int usb_descriptor_fillbuf(void *, unsigned,
971                 const struct usb_descriptor_header **);
972 
973 /* build config descriptor from single descriptor vector */
974 int usb_gadget_config_buf(const struct usb_config_descriptor *config,
975         void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
976 
977 /* copy a NULL-terminated vector of descriptors */
978 struct usb_descriptor_header **usb_copy_descriptors(
979                 struct usb_descriptor_header **);
980 
981 /**
982  * usb_free_descriptors - free descriptors returned by usb_copy_descriptors()
983  * @v: vector of descriptors
984  */
985 static inline void usb_free_descriptors(struct usb_descriptor_header **v)
986 {
987         kfree(v);
988 }
989 
990 struct usb_function;
991 int usb_assign_descriptors(struct usb_function *f,
992                 struct usb_descriptor_header **fs,
993                 struct usb_descriptor_header **hs,
994                 struct usb_descriptor_header **ss);
995 void usb_free_all_descriptors(struct usb_function *f);
996 
997 /*-------------------------------------------------------------------------*/
998 
999 /* utility to simplify map/unmap of usb_requests to/from DMA */
1000 
1001 extern int usb_gadget_map_request(struct usb_gadget *gadget,
1002                 struct usb_request *req, int is_in);
1003 
1004 extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
1005                 struct usb_request *req, int is_in);
1006 
1007 /*-------------------------------------------------------------------------*/
1008 
1009 /* utility to set gadget state properly */
1010 
1011 extern void usb_gadget_set_state(struct usb_gadget *gadget,
1012                 enum usb_device_state state);
1013 
1014 /*-------------------------------------------------------------------------*/
1015 
1016 /* utility wrapping a simple endpoint selection policy */
1017 
1018 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
1019                         struct usb_endpoint_descriptor *);
1020 
1021 
1022 extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *,
1023                         struct usb_endpoint_descriptor *,
1024                         struct usb_ss_ep_comp_descriptor *);
1025 
1026 extern void usb_ep_autoconfig_reset(struct usb_gadget *);
1027 
1028 #endif /* __LINUX_USB_GADGET_H */
1029 

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