From 5a8d651a2bde01e00caf78496390d6ae46df80af Mon Sep 17 00:00:00 2001 From: Felipe Balbi Date: Tue, 31 May 2016 13:07:47 +0300 Subject: usb: gadget: move gadget API functions to udc-core instead of defining all functions as static inlines, let's move them to udc-core and export them with EXPORT_SYMBOL_GPL, that way we can make sure that only GPL drivers will use them. As a side effect, it'll be nicer to add tracepoints to the gadget API. While at that, also fix Kconfig dependencies to avoid randconfig build failures. Acked-By: Sebastian Reichel Acked-by: Peter Chen Signed-off-by: Felipe Balbi --- drivers/usb/gadget/udc/udc-core.c | 573 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 573 insertions(+) (limited to 'drivers/usb/gadget/udc') diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c index e1b2dce..abf0138 100644 --- a/drivers/usb/gadget/udc/udc-core.c +++ b/drivers/usb/gadget/udc/udc-core.c @@ -59,6 +59,579 @@ static int udc_bind_to_driver(struct usb_udc *udc, /* ------------------------------------------------------------------------- */ +/** + * 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). + */ +void usb_ep_set_maxpacket_limit(struct usb_ep *ep, + unsigned maxpacket_limit) +{ + ep->maxpacket_limit = maxpacket_limit; + ep->maxpacket = maxpacket_limit; +} +EXPORT_SYMBOL_GPL(usb_ep_set_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. + */ +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; +} +EXPORT_SYMBOL_GPL(usb_ep_enable); + +/** + * 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. + */ +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; +} +EXPORT_SYMBOL_GPL(usb_ep_disable); + +/** + * 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. + */ +struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, + gfp_t gfp_flags) +{ + return ep->ops->alloc_request(ep, gfp_flags); +} +EXPORT_SYMBOL_GPL(usb_ep_alloc_request); + +/** + * 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). + */ +void usb_ep_free_request(struct usb_ep *ep, + struct usb_request *req) +{ + ep->ops->free_request(ep, req); +} +EXPORT_SYMBOL_GPL(usb_ep_free_request); + +/** + * 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. + */ +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); +} +EXPORT_SYMBOL_GPL(usb_ep_queue); + +/** + * 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). + */ +int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req) +{ + return ep->ops->dequeue(ep, req); +} +EXPORT_SYMBOL_GPL(usb_ep_dequeue); + +/** + * 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. + */ +int usb_ep_set_halt(struct usb_ep *ep) +{ + return ep->ops->set_halt(ep, 1); +} +EXPORT_SYMBOL_GPL(usb_ep_set_halt); + +/** + * 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. + */ +int usb_ep_clear_halt(struct usb_ep *ep) +{ + return ep->ops->set_halt(ep, 0); +} +EXPORT_SYMBOL_GPL(usb_ep_clear_halt); + +/** + * 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. + */ +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); +} +EXPORT_SYMBOL_GPL(usb_ep_set_wedge); + +/** + * 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. + */ +int usb_ep_fifo_status(struct usb_ep *ep) +{ + if (ep->ops->fifo_status) + return ep->ops->fifo_status(ep); + else + return -EOPNOTSUPP; +} +EXPORT_SYMBOL_GPL(usb_ep_fifo_status); + +/** + * 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. + */ +void usb_ep_fifo_flush(struct usb_ep *ep) +{ + if (ep->ops->fifo_flush) + ep->ops->fifo_flush(ep); +} +EXPORT_SYMBOL_GPL(usb_ep_fifo_flush); + +/* ------------------------------------------------------------------------- */ + +/** + * 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. + */ +int usb_gadget_frame_number(struct usb_gadget *gadget) +{ + return gadget->ops->get_frame(gadget); +} +EXPORT_SYMBOL_GPL(usb_gadget_frame_number); + +/** + * 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. + */ +int usb_gadget_wakeup(struct usb_gadget *gadget) +{ + if (!gadget->ops->wakeup) + return -EOPNOTSUPP; + return gadget->ops->wakeup(gadget); +} +EXPORT_SYMBOL_GPL(usb_gadget_wakeup); + +/** + * 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. + */ +int usb_gadget_set_selfpowered(struct usb_gadget *gadget) +{ + if (!gadget->ops->set_selfpowered) + return -EOPNOTSUPP; + return gadget->ops->set_selfpowered(gadget, 1); +} +EXPORT_SYMBOL_GPL(usb_gadget_set_selfpowered); + +/** + * 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. + */ +int usb_gadget_clear_selfpowered(struct usb_gadget *gadget) +{ + if (!gadget->ops->set_selfpowered) + return -EOPNOTSUPP; + return gadget->ops->set_selfpowered(gadget, 0); +} +EXPORT_SYMBOL_GPL(usb_gadget_clear_selfpowered); + +/** + * 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. + */ +int usb_gadget_vbus_connect(struct usb_gadget *gadget) +{ + if (!gadget->ops->vbus_session) + return -EOPNOTSUPP; + return gadget->ops->vbus_session(gadget, 1); +} +EXPORT_SYMBOL_GPL(usb_gadget_vbus_connect); + +/** + * 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. + */ +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); +} +EXPORT_SYMBOL_GPL(usb_gadget_vbus_draw); + +/** + * 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. + */ +int usb_gadget_vbus_disconnect(struct usb_gadget *gadget) +{ + if (!gadget->ops->vbus_session) + return -EOPNOTSUPP; + return gadget->ops->vbus_session(gadget, 0); +} +EXPORT_SYMBOL_GPL(usb_gadget_vbus_disconnect); + +/** + * 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. + */ +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; +} +EXPORT_SYMBOL_GPL(usb_gadget_connect); + +/** + * 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. + */ +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; +} +EXPORT_SYMBOL_GPL(usb_gadget_disconnect); + +/** + * 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. + */ +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; +} +EXPORT_SYMBOL_GPL(usb_gadget_deactivate); + +/** + * 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. + */ +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; +} +EXPORT_SYMBOL_GPL(usb_gadget_activate); + +/* ------------------------------------------------------------------------- */ + #ifdef CONFIG_HAS_DMA int usb_gadget_map_request_by_dev(struct device *dev, -- cgit v1.1