diff options
Diffstat (limited to 'include/linux/usb')
| -rw-r--r-- | include/linux/usb/gadget.h | 585 |
1 files changed, 60 insertions, 525 deletions
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h index fefe8b06a63d..c6e1149ddb0d 100644 --- a/include/linux/usb/gadget.h +++ b/include/linux/usb/gadget.h @@ -228,307 +228,49 @@ struct usb_ep { /*-------------------------------------------------------------------------*/ -/** - * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint - * @ep:the endpoint being configured - * @maxpacket_limit:value of maximum packet size limit - * - * This function should be used only in UDC drivers to initialize endpoint - * (usually in probe function). - */ +#if IS_ENABLED(CONFIG_USB_GADGET) +void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit); +int usb_ep_enable(struct usb_ep *ep); +int usb_ep_disable(struct usb_ep *ep); +struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags); +void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req); +int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags); +int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req); +int usb_ep_set_halt(struct usb_ep *ep); +int usb_ep_clear_halt(struct usb_ep *ep); +int usb_ep_set_wedge(struct usb_ep *ep); +int usb_ep_fifo_status(struct usb_ep *ep); +void usb_ep_fifo_flush(struct usb_ep *ep); +#else static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep, - unsigned maxpacket_limit) -{ - ep->maxpacket_limit = maxpacket_limit; - ep->maxpacket = maxpacket_limit; -} - -/** - * usb_ep_enable - configure endpoint, making it usable - * @ep:the endpoint being configured. may not be the endpoint named "ep0". - * drivers discover endpoints through the ep_list of a usb_gadget. - * - * When configurations are set, or when interface settings change, the driver - * will enable or disable the relevant endpoints. while it is enabled, an - * endpoint may be used for i/o until the driver receives a disconnect() from - * the host or until the endpoint is disabled. - * - * the ep0 implementation (which calls this routine) must ensure that the - * hardware capabilities of each endpoint match the descriptor provided - * for it. for example, an endpoint named "ep2in-bulk" would be usable - * for interrupt transfers as well as bulk, but it likely couldn't be used - * for iso transfers or for endpoint 14. some endpoints are fully - * configurable, with more generic names like "ep-a". (remember that for - * USB, "in" means "towards the USB master".) - * - * returns zero, or a negative error code. - */ + unsigned maxpacket_limit) +{ } static inline int usb_ep_enable(struct usb_ep *ep) -{ - int ret; - - if (ep->enabled) - return 0; - - ret = ep->ops->enable(ep, ep->desc); - if (ret) - return ret; - - ep->enabled = true; - - return 0; -} - -/** - * usb_ep_disable - endpoint is no longer usable - * @ep:the endpoint being unconfigured. may not be the endpoint named "ep0". - * - * no other task may be using this endpoint when this is called. - * any pending and uncompleted requests will complete with status - * indicating disconnect (-ESHUTDOWN) before this call returns. - * gadget drivers must call usb_ep_enable() again before queueing - * requests to the endpoint. - * - * returns zero, or a negative error code. - */ +{ return 0; } static inline int usb_ep_disable(struct usb_ep *ep) -{ - int ret; - - if (!ep->enabled) - return 0; - - ret = ep->ops->disable(ep); - if (ret) - return ret; - - ep->enabled = false; - - return 0; -} - -/** - * usb_ep_alloc_request - allocate a request object to use with this endpoint - * @ep:the endpoint to be used with with the request - * @gfp_flags:GFP_* flags to use - * - * Request objects must be allocated with this call, since they normally - * need controller-specific setup and may even need endpoint-specific - * resources such as allocation of DMA descriptors. - * Requests may be submitted with usb_ep_queue(), and receive a single - * completion callback. Free requests with usb_ep_free_request(), when - * they are no longer needed. - * - * Returns the request, or null if one could not be allocated. - */ +{ return 0; } static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, - gfp_t gfp_flags) -{ - return ep->ops->alloc_request(ep, gfp_flags); -} - -/** - * usb_ep_free_request - frees a request object - * @ep:the endpoint associated with the request - * @req:the request being freed - * - * Reverses the effect of usb_ep_alloc_request(). - * Caller guarantees the request is not queued, and that it will - * no longer be requeued (or otherwise used). - */ + gfp_t gfp_flags) +{ return NULL; } static inline void usb_ep_free_request(struct usb_ep *ep, - struct usb_request *req) -{ - ep->ops->free_request(ep, req); -} - -/** - * usb_ep_queue - queues (submits) an I/O request to an endpoint. - * @ep:the endpoint associated with the request - * @req:the request being submitted - * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't - * pre-allocate all necessary memory with the request. - * - * This tells the device controller to perform the specified request through - * that endpoint (reading or writing a buffer). When the request completes, - * including being canceled by usb_ep_dequeue(), the request's completion - * routine is called to return the request to the driver. Any endpoint - * (except control endpoints like ep0) may have more than one transfer - * request queued; they complete in FIFO order. Once a gadget driver - * submits a request, that request may not be examined or modified until it - * is given back to that driver through the completion callback. - * - * Each request is turned into one or more packets. The controller driver - * never merges adjacent requests into the same packet. OUT transfers - * will sometimes use data that's already buffered in the hardware. - * Drivers can rely on the fact that the first byte of the request's buffer - * always corresponds to the first byte of some USB packet, for both - * IN and OUT transfers. - * - * Bulk endpoints can queue any amount of data; the transfer is packetized - * automatically. The last packet will be short if the request doesn't fill it - * out completely. Zero length packets (ZLPs) should be avoided in portable - * protocols since not all usb hardware can successfully handle zero length - * packets. (ZLPs may be explicitly written, and may be implicitly written if - * the request 'zero' flag is set.) Bulk endpoints may also be used - * for interrupt transfers; but the reverse is not true, and some endpoints - * won't support every interrupt transfer. (Such as 768 byte packets.) - * - * Interrupt-only endpoints are less functional than bulk endpoints, for - * example by not supporting queueing or not handling buffers that are - * larger than the endpoint's maxpacket size. They may also treat data - * toggle differently. - * - * Control endpoints ... after getting a setup() callback, the driver queues - * one response (even if it would be zero length). That enables the - * status ack, after transferring data as specified in the response. Setup - * functions may return negative error codes to generate protocol stalls. - * (Note that some USB device controllers disallow protocol stall responses - * in some cases.) When control responses are deferred (the response is - * written after the setup callback returns), then usb_ep_set_halt() may be - * used on ep0 to trigger protocol stalls. Depending on the controller, - * it may not be possible to trigger a status-stage protocol stall when the - * data stage is over, that is, from within the response's completion - * routine. - * - * For periodic endpoints, like interrupt or isochronous ones, the usb host - * arranges to poll once per interval, and the gadget driver usually will - * have queued some data to transfer at that time. - * - * Returns zero, or a negative error code. Endpoints that are not enabled - * report errors; errors will also be - * reported when the usb peripheral is disconnected. - */ -static inline int usb_ep_queue(struct usb_ep *ep, - struct usb_request *req, gfp_t gfp_flags) -{ - if (WARN_ON_ONCE(!ep->enabled && ep->address)) - return -ESHUTDOWN; - - return ep->ops->queue(ep, req, gfp_flags); -} - -/** - * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint - * @ep:the endpoint associated with the request - * @req:the request being canceled - * - * If the request is still active on the endpoint, it is dequeued and its - * completion routine is called (with status -ECONNRESET); else a negative - * error code is returned. This is guaranteed to happen before the call to - * usb_ep_dequeue() returns. - * - * Note that some hardware can't clear out write fifos (to unlink the request - * at the head of the queue) except as part of disconnecting from usb. Such - * restrictions prevent drivers from supporting configuration changes, - * even to configuration zero (a "chapter 9" requirement). - */ + struct usb_request *req) +{ } +static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, + gfp_t gfp_flags) +{ return 0; } static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req) -{ - return ep->ops->dequeue(ep, req); -} - -/** - * usb_ep_set_halt - sets the endpoint halt feature. - * @ep: the non-isochronous endpoint being stalled - * - * Use this to stall an endpoint, perhaps as an error report. - * Except for control endpoints, - * the endpoint stays halted (will not stream any data) until the host - * clears this feature; drivers may need to empty the endpoint's request - * queue first, to make sure no inappropriate transfers happen. - * - * Note that while an endpoint CLEAR_FEATURE will be invisible to the - * gadget driver, a SET_INTERFACE will not be. To reset endpoints for the - * current altsetting, see usb_ep_clear_halt(). When switching altsettings, - * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints. - * - * Returns zero, or a negative error code. On success, this call sets - * underlying hardware state that blocks data transfers. - * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any - * transfer requests are still queued, or if the controller hardware - * (usually a FIFO) still holds bytes that the host hasn't collected. - */ +{ return 0; } static inline int usb_ep_set_halt(struct usb_ep *ep) -{ - return ep->ops->set_halt(ep, 1); -} - -/** - * usb_ep_clear_halt - clears endpoint halt, and resets toggle - * @ep:the bulk or interrupt endpoint being reset - * - * Use this when responding to the standard usb "set interface" request, - * for endpoints that aren't reconfigured, after clearing any other state - * in the endpoint's i/o queue. - * - * Returns zero, or a negative error code. On success, this call clears - * the underlying hardware state reflecting endpoint halt and data toggle. - * Note that some hardware can't support this request (like pxa2xx_udc), - * and accordingly can't correctly implement interface altsettings. - */ +{ return 0; } static inline int usb_ep_clear_halt(struct usb_ep *ep) -{ - return ep->ops->set_halt(ep, 0); -} - -/** - * usb_ep_set_wedge - sets the halt feature and ignores clear requests - * @ep: the endpoint being wedged - * - * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT) - * requests. If the gadget driver clears the halt status, it will - * automatically unwedge the endpoint. - * - * Returns zero on success, else negative errno. - */ -static inline int -usb_ep_set_wedge(struct usb_ep *ep) -{ - if (ep->ops->set_wedge) - return ep->ops->set_wedge(ep); - else - return ep->ops->set_halt(ep, 1); -} - -/** - * usb_ep_fifo_status - returns number of bytes in fifo, or error - * @ep: the endpoint whose fifo status is being checked. - * - * FIFO endpoints may have "unclaimed data" in them in certain cases, - * such as after aborted transfers. Hosts may not have collected all - * the IN data written by the gadget driver (and reported by a request - * completion). The gadget driver may not have collected all the data - * written OUT to it by the host. Drivers that need precise handling for - * fault reporting or recovery may need to use this call. - * - * This returns the number of such bytes in the fifo, or a negative - * errno if the endpoint doesn't use a FIFO or doesn't support such - * precise handling. - */ +{ return 0; } +static inline int usb_ep_set_wedge(struct usb_ep *ep) +{ return 0; } static inline int usb_ep_fifo_status(struct usb_ep *ep) -{ - if (ep->ops->fifo_status) - return ep->ops->fifo_status(ep); - else - return -EOPNOTSUPP; -} - -/** - * usb_ep_fifo_flush - flushes contents of a fifo - * @ep: the endpoint whose fifo is being flushed. - * - * This call may be used to flush the "unclaimed data" that may exist in - * an endpoint fifo after abnormal transaction terminations. The call - * must never be used except when endpoint is not being used for any - * protocol translation. - */ +{ return 0; } static inline void usb_ep_fifo_flush(struct usb_ep *ep) -{ - if (ep->ops->fifo_flush) - ep->ops->fifo_flush(ep); -} - +{ } +#endif /* USB_GADGET */ /*-------------------------------------------------------------------------*/ @@ -760,251 +502,44 @@ static inline int gadget_is_otg(struct usb_gadget *g) #endif } -/** - * usb_gadget_frame_number - returns the current frame number - * @gadget: controller that reports the frame number - * - * Returns the usb frame number, normally eleven bits from a SOF packet, - * or negative errno if this device doesn't support this capability. - */ -static inline int usb_gadget_frame_number(struct usb_gadget *gadget) -{ - return gadget->ops->get_frame(gadget); -} +/*-------------------------------------------------------------------------*/ -/** - * usb_gadget_wakeup - tries to wake up the host connected to this gadget - * @gadget: controller used to wake up the host - * - * Returns zero on success, else negative error code if the hardware - * doesn't support such attempts, or its support has not been enabled - * by the usb host. Drivers must return device descriptors that report - * their ability to support this, or hosts won't enable it. - * - * This may also try to use SRP to wake the host and start enumeration, - * even if OTG isn't otherwise in use. OTG devices may also start - * remote wakeup even when hosts don't explicitly enable it. - */ +#if IS_ENABLED(CONFIG_USB_GADGET) +int usb_gadget_frame_number(struct usb_gadget *gadget); +int usb_gadget_wakeup(struct usb_gadget *gadget); +int usb_gadget_set_selfpowered(struct usb_gadget *gadget); +int usb_gadget_clear_selfpowered(struct usb_gadget *gadget); +int usb_gadget_vbus_connect(struct usb_gadget *gadget); +int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA); +int usb_gadget_vbus_disconnect(struct usb_gadget *gadget); +int usb_gadget_connect(struct usb_gadget *gadget); +int usb_gadget_disconnect(struct usb_gadget *gadget); +int usb_gadget_deactivate(struct usb_gadget *gadget); +int usb_gadget_activate(struct usb_gadget *gadget); +#else +static inline int usb_gadget_frame_number(struct usb_gadget *gadget) +{ return 0; } static inline int usb_gadget_wakeup(struct usb_gadget *gadget) -{ - if (!gadget->ops->wakeup) - return -EOPNOTSUPP; - return gadget->ops->wakeup(gadget); -} - -/** - * usb_gadget_set_selfpowered - sets the device selfpowered feature. - * @gadget:the device being declared as self-powered - * - * this affects the device status reported by the hardware driver - * to reflect that it now has a local power supply. - * - * returns zero on success, else negative errno. - */ +{ return 0; } static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget) -{ - if (!gadget->ops->set_selfpowered) - return -EOPNOTSUPP; - return gadget->ops->set_selfpowered(gadget, 1); -} - -/** - * usb_gadget_clear_selfpowered - clear the device selfpowered feature. - * @gadget:the device being declared as bus-powered - * - * this affects the device status reported by the hardware driver. - * some hardware may not support bus-powered operation, in which - * case this feature's value can never change. - * - * returns zero on success, else negative errno. - */ +{ return 0; } static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget) -{ - if (!gadget->ops->set_selfpowered) - return -EOPNOTSUPP; - return gadget->ops->set_selfpowered(gadget, 0); -} - -/** - * usb_gadget_vbus_connect - Notify controller that VBUS is powered - * @gadget:The device which now has VBUS power. - * Context: can sleep - * - * This call is used by a driver for an external transceiver (or GPIO) - * that detects a VBUS power session starting. Common responses include - * resuming the controller, activating the D+ (or D-) pullup to let the - * host detect that a USB device is attached, and starting to draw power - * (8mA or possibly more, especially after SET_CONFIGURATION). - * - * Returns zero on success, else negative errno. - */ +{ return 0; } static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget) -{ - if (!gadget->ops->vbus_session) - return -EOPNOTSUPP; - return gadget->ops->vbus_session(gadget, 1); -} - -/** - * usb_gadget_vbus_draw - constrain controller's VBUS power usage - * @gadget:The device whose VBUS usage is being described - * @mA:How much current to draw, in milliAmperes. This should be twice - * the value listed in the configuration descriptor bMaxPower field. - * - * This call is used by gadget drivers during SET_CONFIGURATION calls, - * reporting how much power the device may consume. For example, this - * could affect how quickly batteries are recharged. - * - * Returns zero on success, else negative errno. - */ +{ return 0; } static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA) -{ - if (!gadget->ops->vbus_draw) - return -EOPNOTSUPP; - return gadget->ops->vbus_draw(gadget, mA); -} - -/** - * usb_gadget_vbus_disconnect - notify controller about VBUS session end - * @gadget:the device whose VBUS supply is being described - * Context: can sleep - * - * This call is used by a driver for an external transceiver (or GPIO) - * that detects a VBUS power session ending. Common responses include - * reversing everything done in usb_gadget_vbus_connect(). - * - * Returns zero on success, else negative errno. - */ +{ return 0; } static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget) -{ - if (!gadget->ops->vbus_session) - return -EOPNOTSUPP; - return gadget->ops->vbus_session(gadget, 0); -} - -/** - * usb_gadget_connect - software-controlled connect to USB host - * @gadget:the peripheral being connected - * - * Enables the D+ (or potentially D-) pullup. The host will start - * enumerating this gadget when the pullup is active and a VBUS session - * is active (the link is powered). This pullup is always enabled unless - * usb_gadget_disconnect() has been used to disable it. - * - * Returns zero on success, else negative errno. - */ +{ return 0; } static inline int usb_gadget_connect(struct usb_gadget *gadget) -{ - int ret; - - if (!gadget->ops->pullup) - return -EOPNOTSUPP; - - if (gadget->deactivated) { - /* - * If gadget is deactivated we only save new state. - * Gadget will be connected automatically after activation. - */ - gadget->connected = true; - return 0; - } - - ret = gadget->ops->pullup(gadget, 1); - if (!ret) - gadget->connected = 1; - return ret; -} - -/** - * usb_gadget_disconnect - software-controlled disconnect from USB host - * @gadget:the peripheral being disconnected - * - * Disables the D+ (or potentially D-) pullup, which the host may see - * as a disconnect (when a VBUS session is active). Not all systems - * support software pullup controls. - * - * Returns zero on success, else negative errno. - */ +{ return 0; } static inline int usb_gadget_disconnect(struct usb_gadget *gadget) -{ - int ret; - - if (!gadget->ops->pullup) - return -EOPNOTSUPP; - - if (gadget->deactivated) { - /* - * If gadget is deactivated we only save new state. - * Gadget will stay disconnected after activation. - */ - gadget->connected = false; - return 0; - } - - ret = gadget->ops->pullup(gadget, 0); - if (!ret) - gadget->connected = 0; - return ret; -} - -/** - * usb_gadget_deactivate - deactivate function which is not ready to work - * @gadget: the peripheral being deactivated - * - * This routine may be used during the gadget driver bind() call to prevent - * the peripheral from ever being visible to the USB host, unless later - * usb_gadget_activate() is called. For example, user mode components may - * need to be activated before the system can talk to hosts. - * - * Returns zero on success, else negative errno. - */ +{ return 0; } static inline int usb_gadget_deactivate(struct usb_gadget *gadget) -{ - int ret; - - if (gadget->deactivated) - return 0; - - if (gadget->connected) { - ret = usb_gadget_disconnect(gadget); - if (ret) - return ret; - /* - * If gadget was being connected before deactivation, we want - * to reconnect it in usb_gadget_activate(). - */ - gadget->connected = true; - } - gadget->deactivated = true; - - return 0; -} - -/** - * usb_gadget_activate - activate function which is not ready to work - * @gadget: the peripheral being activated - * - * This routine activates gadget which was previously deactivated with - * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed. - * - * Returns zero on success, else negative errno. - */ +{ return 0; } static inline int usb_gadget_activate(struct usb_gadget *gadget) -{ - if (!gadget->deactivated) - return 0; - - gadget->deactivated = false; - - /* - * If gadget has been connected before deactivation, or became connected - * while it was being deactivated, we call usb_gadget_connect(). - */ - if (gadget->connected) - return usb_gadget_connect(gadget); - - return 0; -} +{ return 0; } +#endif /* CONFIG_USB_GADGET */ /*-------------------------------------------------------------------------*/ |