// SPDX-License-Identifier: GPL-2.0 /* * udc.c - Core UDC Framework * * Copyright (C) 2010 Texas Instruments * Author: Felipe Balbi */ #include #include #include #include #include #include #include #include #include #include #include #include "trace.h" /** * struct usb_udc - describes one usb device controller * @driver: the gadget driver pointer. For use by the class code * @dev: the child device to the actual controller * @gadget: the gadget. For use by the class code * @list: for use by the udc class driver * @vbus: for udcs who care about vbus status, this value is real vbus status; * for udcs who do not care about vbus status, this value is always true * @started: the UDC's started state. True if the UDC had started. * * This represents the internal data structure which is used by the UDC-class * to hold information about udc driver and gadget together. */ struct usb_udc { struct usb_gadget_driver *driver; struct usb_gadget *gadget; struct device dev; struct list_head list; bool vbus; bool started; }; static struct class *udc_class; static LIST_HEAD(udc_list); static LIST_HEAD(gadget_driver_pending_list); static DEFINE_MUTEX(udc_lock); /** * protects udc->vbus, udc->started, gadget->connect, gadget->deactivate related * functions. usb_gadget_connect_locked, usb_gadget_disconnect_locked, * usb_udc_connect_control_locked, usb_gadget_udc_start_locked, usb_gadget_udc_stop_locked are * called with this lock held. */ static DEFINE_MUTEX(connect_lock); static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *driver); /* ------------------------------------------------------------------------- */ /** * 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; trace_usb_ep_set_maxpacket_limit(ep, 0); } 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 host".) * * This routine may be called in an atomic (interrupt) context. * * returns zero, or a negative error code. */ int usb_ep_enable(struct usb_ep *ep) { int ret = 0; if (ep->enabled) goto out; /* UDC drivers can't handle endpoints with maxpacket size 0 */ if (usb_endpoint_maxp(ep->desc) == 0) { /* * We should log an error message here, but we can't call * dev_err() because there's no way to find the gadget * given only ep. */ ret = -EINVAL; goto out; } ret = ep->ops->enable(ep, ep->desc); if (ret) goto out; ep->enabled = true; out: trace_usb_ep_enable(ep, ret); return ret; } 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. * * This routine may be called in an atomic (interrupt) context. * * returns zero, or a negative error code. */ int usb_ep_disable(struct usb_ep *ep) { int ret = 0; if (!ep->enabled) goto out; ret = ep->ops->disable(ep); if (ret) goto out; ep->enabled = false; out: trace_usb_ep_disable(ep, ret); return ret; } 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) { struct usb_request *req = NULL; req = ep->ops->alloc_request(ep, gfp_flags); trace_usb_ep_alloc_request(ep, req, req ? 0 : -ENOMEM); return req; } 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) { trace_usb_ep_free_request(ep, req, 0); 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. * * Note that @req's ->complete() callback must never be called from * within usb_ep_queue() as that can create deadlock situations. * * This routine may be called in interrupt context. * * 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. * * If and only if @req is successfully queued (the return value is zero), * @req->complete() will be called exactly once, when the Gadget core and * UDC are finished with the request. When the completion function is called, * control of the request is returned to the device driver which submitted it. * The completion handler may then immediately free or reuse @req. */ int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags) { int ret = 0; if (WARN_ON_ONCE(!ep->enabled && ep->address)) { ret = -ESHUTDOWN; goto out; } ret = ep->ops->queue(ep, req, gfp_flags); out: trace_usb_ep_queue(ep, req, ret); return ret; } 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 * eventually its completion routine is called (with status -ECONNRESET); * else a negative error code is returned. This routine is asynchronous, * that is, it may return before the completion routine runs. * * 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). * * This routine may be called in interrupt context. */ int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req) { int ret; ret = ep->ops->dequeue(ep, req); trace_usb_ep_dequeue(ep, req, ret); return ret; } 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. * * This routine may be called in interrupt context. * * 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) { int ret; ret = ep->ops->set_halt(ep, 1); trace_usb_ep_set_halt(ep, ret); return ret; } 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. * * This routine may be called in interrupt context. * * 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) { int ret; ret = ep->ops->set_halt(ep, 0); trace_usb_ep_clear_halt(ep, ret); return ret; } 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. * * This routine may be called in interrupt context. * * Returns zero on success, else negative errno. */ int usb_ep_set_wedge(struct usb_ep *ep) { int ret; if (ep->ops->set_wedge) ret = ep->ops->set_wedge(ep); else ret = ep->ops->set_halt(ep, 1); trace_usb_ep_set_wedge(ep, ret); return ret; } 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 routine may be called in interrupt context. * * 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) { int ret; if (ep->ops->fifo_status) ret = ep->ops->fifo_status(ep); else ret = -EOPNOTSUPP; trace_usb_ep_fifo_status(ep, ret); return ret; } 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. * * This routine may be called in interrupt context. */ void usb_ep_fifo_flush(struct usb_ep *ep) { if (ep->ops->fifo_flush) ep->ops->fifo_flush(ep); trace_usb_ep_fifo_flush(ep, 0); } 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) { int ret; ret = gadget->ops->get_frame(gadget); trace_usb_gadget_frame_number(gadget, ret); return ret; } 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) { int ret = 0; if (!gadget->ops->wakeup) { ret = -EOPNOTSUPP; goto out; } ret = gadget->ops->wakeup(gadget); out: trace_usb_gadget_wakeup(gadget, ret); return ret; } 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) { int ret = 0; if (!gadget->ops->set_selfpowered) { ret = -EOPNOTSUPP; goto out; } ret = gadget->ops->set_selfpowered(gadget, 1); out: trace_usb_gadget_set_selfpowered(gadget, ret); return ret; } 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) { int ret = 0; if (!gadget->ops->set_selfpowered) { ret = -EOPNOTSUPP; goto out; } ret = gadget->ops->set_selfpowered(gadget, 0); out: trace_usb_gadget_clear_selfpowered(gadget, ret); return ret; } 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) { int ret = 0; if (!gadget->ops->vbus_session) { ret = -EOPNOTSUPP; goto out; } ret = gadget->ops->vbus_session(gadget, 1); out: trace_usb_gadget_vbus_connect(gadget, ret); return ret; } 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) { int ret = 0; if (!gadget->ops->vbus_draw) { ret = -EOPNOTSUPP; goto out; } ret = gadget->ops->vbus_draw(gadget, mA); if (!ret) gadget->mA = mA; out: trace_usb_gadget_vbus_draw(gadget, ret); return ret; } 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) { int ret = 0; if (!gadget->ops->vbus_session) { ret = -EOPNOTSUPP; goto out; } ret = gadget->ops->vbus_session(gadget, 0); out: trace_usb_gadget_vbus_disconnect(gadget, ret); return ret; } EXPORT_SYMBOL_GPL(usb_gadget_vbus_disconnect); /* Internal version of usb_gadget_connect needs to be called with connect_lock held. */ static int usb_gadget_connect_locked(struct usb_gadget *gadget) __must_hold(&connect_lock) { int ret = 0; if (!gadget->ops->pullup) { ret = -EOPNOTSUPP; goto out; } if (gadget->deactivated || !gadget->udc->started) { /* * If gadget is deactivated we only save new state. * Gadget will be connected automatically after activation. * * udc first needs to be started before gadget can be pulled up. */ gadget->connected = true; goto out; } ret = gadget->ops->pullup(gadget, 1); if (!ret) gadget->connected = 1; out: trace_usb_gadget_connect(gadget, ret); return ret; } /** * 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). * * Returns zero on success, else negative errno. */ int usb_gadget_connect(struct usb_gadget *gadget) { int ret; mutex_lock(&connect_lock); ret = usb_gadget_connect_locked(gadget); mutex_unlock(&connect_lock); return ret; } EXPORT_SYMBOL_GPL(usb_gadget_connect); /* Internal version of usb_gadget_disconnect needs to be called with connect_lock held. */ static int usb_gadget_disconnect_locked(struct usb_gadget *gadget) __must_hold(&connect_lock) { int ret = 0; if (!gadget->ops->pullup) { ret = -EOPNOTSUPP; goto out; } if (!gadget->connected) goto out; if (gadget->deactivated || !gadget->udc->started) { /* * If gadget is deactivated we only save new state. * Gadget will stay disconnected after activation. * * udc should have been started before gadget being pulled down. */ gadget->connected = false; goto out; } ret = gadget->ops->pullup(gadget, 0); if (!ret) gadget->connected = 0; if (gadget->udc->driver) gadget->udc->driver->disconnect(gadget); out: trace_usb_gadget_disconnect(gadget, ret); 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. * * Following a successful disconnect, invoke the ->disconnect() callback * for the current gadget driver so that UDC drivers don't need to. * * Returns zero on success, else negative errno. */ int usb_gadget_disconnect(struct usb_gadget *gadget) { int ret; mutex_lock(&connect_lock); ret = usb_gadget_disconnect_locked(gadget); mutex_unlock(&connect_lock); 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. * * This routine may sleep; it must not be called in interrupt context * (such as from within a gadget driver's disconnect() callback). * * Returns zero on success, else negative errno. */ int usb_gadget_deactivate(struct usb_gadget *gadget) { int ret = 0; if (gadget->deactivated) goto out; mutex_lock(&connect_lock); if (gadget->connected) { ret = usb_gadget_disconnect_locked(gadget); if (ret) goto unlock; /* * If gadget was being connected before deactivation, we want * to reconnect it in usb_gadget_activate(). */ gadget->connected = true; } gadget->deactivated = true; unlock: mutex_unlock(&connect_lock); out: trace_usb_gadget_deactivate(gadget, ret); return ret; } 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. * * This routine may sleep; it must not be called in interrupt context. * * Returns zero on success, else negative errno. */ int usb_gadget_activate(struct usb_gadget *gadget) { int ret = 0; if (!gadget->deactivated) goto out; mutex_lock(&connect_lock); 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) ret = usb_gadget_connect_locked(gadget); mutex_unlock(&connect_lock); out: trace_usb_gadget_activate(gadget, ret); return ret; } EXPORT_SYMBOL_GPL(usb_gadget_activate); /* ------------------------------------------------------------------------- */ #ifdef CONFIG_HAS_DMA int usb_gadget_map_request_by_dev(struct device *dev, struct usb_request *req, int is_in) { if (req->length == 0) return 0; if (req->num_sgs) { int mapped; mapped = dma_map_sg(dev, req->sg, req->num_sgs, is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE); if (mapped == 0) { dev_err(dev, "failed to map SGs\n"); return -EFAULT; } req->num_mapped_sgs = mapped; } else { if (is_vmalloc_addr(req->buf)) { dev_err(dev, "buffer is not dma capable\n"); return -EFAULT; } else if (object_is_on_stack(req->buf)) { dev_err(dev, "buffer is on stack\n"); return -EFAULT; } req->dma = dma_map_single(dev, req->buf, req->length, is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE); if (dma_mapping_error(dev, req->dma)) { dev_err(dev, "failed to map buffer\n"); return -EFAULT; } req->dma_mapped = 1; } return 0; } EXPORT_SYMBOL_GPL(usb_gadget_map_request_by_dev); int usb_gadget_map_request(struct usb_gadget *gadget, struct usb_request *req, int is_in) { return usb_gadget_map_request_by_dev(gadget->dev.parent, req, is_in); } EXPORT_SYMBOL_GPL(usb_gadget_map_request); void usb_gadget_unmap_request_by_dev(struct device *dev, struct usb_request *req, int is_in) { if (req->length == 0) return; if (req->num_mapped_sgs) { dma_unmap_sg(dev, req->sg, req->num_sgs, is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE); req->num_mapped_sgs = 0; } else if (req->dma_mapped) { dma_unmap_single(dev, req->dma, req->length, is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE); req->dma_mapped = 0; } } EXPORT_SYMBOL_GPL(usb_gadget_unmap_request_by_dev); void usb_gadget_unmap_request(struct usb_gadget *gadget, struct usb_request *req, int is_in) { usb_gadget_unmap_request_by_dev(gadget->dev.parent, req, is_in); } EXPORT_SYMBOL_GPL(usb_gadget_unmap_request); #endif /* CONFIG_HAS_DMA */ /* ------------------------------------------------------------------------- */ /** * usb_gadget_giveback_request - give the request back to the gadget layer * @ep: the endpoint to be used with with the request * @req: the request being given back * * Context: in_interrupt() * * This is called by device controller drivers in order to return the * completed request back to the gadget layer. */ void usb_gadget_giveback_request(struct usb_ep *ep, struct usb_request *req) { if (likely(req->status == 0)) usb_led_activity(USB_LED_EVENT_GADGET); trace_usb_gadget_giveback_request(ep, req, 0); req->complete(ep, req); } EXPORT_SYMBOL_GPL(usb_gadget_giveback_request); /* ------------------------------------------------------------------------- */ /** * gadget_find_ep_by_name - returns ep whose name is the same as sting passed * in second parameter or NULL if searched endpoint not found * @g: controller to check for quirk * @name: name of searched endpoint */ struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g, const char *name) { struct usb_ep *ep; gadget_for_each_ep(ep, g) { if (!strcmp(ep->name, name)) return ep; } return NULL; } EXPORT_SYMBOL_GPL(gadget_find_ep_by_name); /* ------------------------------------------------------------------------- */ int usb_gadget_ep_match_desc(struct usb_gadget *gadget, struct usb_ep *ep, struct usb_endpoint_descriptor *desc, struct usb_ss_ep_comp_descriptor *ep_comp) { u8 type; u16 max; int num_req_streams = 0; /* endpoint already claimed? */ if (ep->claimed) return 0; type = usb_endpoint_type(desc); max = usb_endpoint_maxp(desc); if (usb_endpoint_dir_in(desc) && !ep->caps.dir_in) return 0; if (usb_endpoint_dir_out(desc) && !ep->caps.dir_out) return 0; if (max > ep->maxpacket_limit) return 0; /* "high bandwidth" works only at high speed */ if (!gadget_is_dualspeed(gadget) && usb_endpoint_maxp_mult(desc) > 1) return 0; switch (type) { case USB_ENDPOINT_XFER_CONTROL: /* only support ep0 for portable CONTROL traffic */ return 0; case USB_ENDPOINT_XFER_ISOC: if (!ep->caps.type_iso) return 0; /* ISO: limit 1023 bytes full speed, 1024 high/super speed */ if (!gadget_is_dualspeed(gadget) && max > 1023) return 0; break; case USB_ENDPOINT_XFER_BULK: if (!ep->caps.type_bulk) return 0; if (ep_comp && gadget_is_superspeed(gadget)) { /* Get the number of required streams from the * EP companion descriptor and see if the EP * matches it */ num_req_streams = ep_comp->bmAttributes & 0x1f; if (num_req_streams > ep->max_streams) return 0; } break; case USB_ENDPOINT_XFER_INT: /* Bulk endpoints handle interrupt transfers, * except the toggle-quirky iso-synch kind */ if (!ep->caps.type_int && !ep->caps.type_bulk) return 0; /* INT: limit 64 bytes full speed, 1024 high/super speed */ if (!gadget_is_dualspeed(gadget) && max > 64) return 0; break; } return 1; } EXPORT_SYMBOL_GPL(usb_gadget_ep_match_desc); /** * usb_gadget_check_config - checks if the UDC can support the binded * configuration * @gadget: controller to check the USB configuration * * Ensure that a UDC is able to support the requested resources by a * configuration, and that there are no resource limitations, such as * internal memory allocated to all requested endpoints. * * Returns zero on success, else a negative errno. */ int usb_gadget_check_config(struct usb_gadget *gadget) { if (gadget->ops->check_config) return gadget->ops->check_config(gadget); return 0; } EXPORT_SYMBOL_GPL(usb_gadget_check_config); /* ------------------------------------------------------------------------- */ static void usb_gadget_state_work(struct work_struct *work) { struct usb_gadget *gadget = work_to_gadget(work); struct usb_udc *udc = gadget->udc; if (udc) sysfs_notify(&udc->dev.kobj, NULL, "state"); } void usb_gadget_set_state(struct usb_gadget *gadget, enum usb_device_state state) { gadget->state = state; schedule_work(&gadget->work); } EXPORT_SYMBOL_GPL(usb_gadget_set_state); /* ------------------------------------------------------------------------- */ /* Acquire connect_lock before calling this function. */ static void usb_udc_connect_control_locked(struct usb_udc *udc) __must_hold(&connect_lock) { if (udc->vbus && udc->started) usb_gadget_connect_locked(udc->gadget); else usb_gadget_disconnect_locked(udc->gadget); } /** * usb_udc_vbus_handler - updates the udc core vbus status, and try to * connect or disconnect gadget * @gadget: The gadget which vbus change occurs * @status: The vbus status * * The udc driver calls it when it wants to connect or disconnect gadget * according to vbus status. */ void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status) { struct usb_udc *udc = gadget->udc; mutex_lock(&connect_lock); if (udc) { udc->vbus = status; usb_udc_connect_control_locked(udc); } mutex_unlock(&connect_lock); } EXPORT_SYMBOL_GPL(usb_udc_vbus_handler); /** * usb_gadget_udc_reset - notifies the udc core that bus reset occurs * @gadget: The gadget which bus reset occurs * @driver: The gadget driver we want to notify * * If the udc driver has bus reset handler, it needs to call this when the bus * reset occurs, it notifies the gadget driver that the bus reset occurs as * well as updates gadget state. */ void usb_gadget_udc_reset(struct usb_gadget *gadget, struct usb_gadget_driver *driver) { driver->reset(gadget); usb_gadget_set_state(gadget, USB_STATE_DEFAULT); } EXPORT_SYMBOL_GPL(usb_gadget_udc_reset); /** * usb_gadget_udc_start_locked - tells usb device controller to start up * @udc: The UDC to be started * * This call is issued by the UDC Class driver when it's about * to register a gadget driver to the device controller, before * calling gadget driver's bind() method. * * It allows the controller to be powered off until strictly * necessary to have it powered on. * * Returns zero on success, else negative errno. * * Caller should acquire connect_lock before invoking this function. */ static inline int usb_gadget_udc_start_locked(struct usb_udc *udc) __must_hold(&connect_lock) { int ret; if (udc->started) { dev_err(&udc->dev, "UDC had already started\n"); return -EBUSY; } ret = udc->gadget->ops->udc_start(udc->gadget, udc->driver); if (!ret) udc->started = true; return ret; } /** * usb_gadget_udc_stop_locked - tells usb device controller we don't need it anymore * @udc: The UDC to be stopped * * This call is issued by the UDC Class driver after calling * gadget driver's unbind() method. * * The details are implementation specific, but it can go as * far as powering off UDC completely and disable its data * line pullups. * * Caller should acquire connect lock before invoking this function. */ static inline void usb_gadget_udc_stop_locked(struct usb_udc *udc) __must_hold(&connect_lock) { if (!udc->started) { dev_err(&udc->dev, "UDC had already stopped\n"); return; } udc->gadget->ops->udc_stop(udc->gadget); udc->started = false; } /** * usb_gadget_udc_set_speed - tells usb device controller speed supported by * current driver * @udc: The device we want to set maximum speed * @speed: The maximum speed to allowed to run * * This call is issued by the UDC Class driver before calling * usb_gadget_udc_start() in order to make sure that we don't try to * connect on speeds the gadget driver doesn't support. */ static inline void usb_gadget_udc_set_speed(struct usb_udc *udc, enum usb_device_speed speed) { struct usb_gadget *gadget = udc->gadget; enum usb_device_speed s; if (speed == USB_SPEED_UNKNOWN) s = gadget->max_speed; else s = min(speed, gadget->max_speed); if (s == USB_SPEED_SUPER_PLUS && gadget->ops->udc_set_ssp_rate) gadget->ops->udc_set_ssp_rate(gadget, gadget->max_ssp_rate); else if (gadget->ops->udc_set_speed) gadget->ops->udc_set_speed(gadget, s); } /** * usb_gadget_enable_async_callbacks - tell usb device controller to enable asynchronous callbacks * @udc: The UDC which should enable async callbacks * * This routine is used when binding gadget drivers. It undoes the effect * of usb_gadget_disable_async_callbacks(); the UDC driver should enable IRQs * (if necessary) and resume issuing callbacks. * * This routine will always be called in process context. */ static inline void usb_gadget_enable_async_callbacks(struct usb_udc *udc) { struct usb_gadget *gadget = udc->gadget; if (gadget->ops->udc_async_callbacks) gadget->ops->udc_async_callbacks(gadget, true); } /** * usb_gadget_disable_async_callbacks - tell usb device controller to disable asynchronous callbacks * @udc: The UDC which should disable async callbacks * * This routine is used when unbinding gadget drivers. It prevents a race: * The UDC driver doesn't know when the gadget driver's ->unbind callback * runs, so unless it is told to disable asynchronous callbacks, it might * issue a callback (such as ->disconnect) after the unbind has completed. * * After this function runs, the UDC driver must suppress all ->suspend, * ->resume, ->disconnect, ->reset, and ->setup callbacks to the gadget driver * until async callbacks are again enabled. A simple-minded but effective * way to accomplish this is to tell the UDC hardware not to generate any * more IRQs. * * Request completion callbacks must still be issued. However, it's okay * to defer them until the request is cancelled, since the pull-up will be * turned off during the time period when async callbacks are disabled. * * This routine will always be called in process context. */ static inline void usb_gadget_disable_async_callbacks(struct usb_udc *udc) { struct usb_gadget *gadget = udc->gadget; if (gadget->ops->udc_async_callbacks) gadget->ops->udc_async_callbacks(gadget, false); } /** * usb_udc_release - release the usb_udc struct * @dev: the dev member within usb_udc * * This is called by driver's core in order to free memory once the last * reference is released. */ static void usb_udc_release(struct device *dev) { struct usb_udc *udc; udc = container_of(dev, struct usb_udc, dev); dev_dbg(dev, "releasing '%s'\n", dev_name(dev)); kfree(udc); } static const struct attribute_group *usb_udc_attr_groups[]; static void usb_udc_nop_release(struct device *dev) { dev_vdbg(dev, "%s\n", __func__); } /* should be called with udc_lock held */ static int check_pending_gadget_drivers(struct usb_udc *udc) { struct usb_gadget_driver *driver; int ret = 0; list_for_each_entry(driver, &gadget_driver_pending_list, pending) if (!driver->udc_name || strcmp(driver->udc_name, dev_name(&udc->dev)) == 0) { ret = udc_bind_to_driver(udc, driver); if (ret != -EPROBE_DEFER) list_del_init(&driver->pending); break; } return ret; } /** * usb_initialize_gadget - initialize a gadget and its embedded struct device * @parent: the parent device to this udc. Usually the controller driver's * device. * @gadget: the gadget to be initialized. * @release: a gadget release function. * * Returns zero on success, negative errno otherwise. * Calls the gadget release function in the latter case. */ void usb_initialize_gadget(struct device *parent, struct usb_gadget *gadget, void (*release)(struct device *dev)) { dev_set_name(&gadget->dev, "gadget"); INIT_WORK(&gadget->work, usb_gadget_state_work); gadget->dev.parent = parent; if (release) gadget->dev.release = release; else gadget->dev.release = usb_udc_nop_release; device_initialize(&gadget->dev); } EXPORT_SYMBOL_GPL(usb_initialize_gadget); /** * usb_add_gadget - adds a new gadget to the udc class driver list * @gadget: the gadget to be added to the list. * * Returns zero on success, negative errno otherwise. * Does not do a final usb_put_gadget() if an error occurs. */ int usb_add_gadget(struct usb_gadget *gadget) { struct usb_udc *udc; int ret = -ENOMEM; udc = kzalloc(sizeof(*udc), GFP_KERNEL); if (!udc) goto error; device_initialize(&udc->dev); udc->dev.release = usb_udc_release; udc->dev.class = udc_class; udc->dev.groups = usb_udc_attr_groups; udc->dev.parent = gadget->dev.parent; ret = dev_set_name(&udc->dev, "%s", kobject_name(&gadget->dev.parent->kobj)); if (ret) goto err_put_udc; ret = device_add(&gadget->dev); if (ret) goto err_put_udc; udc->gadget = gadget; gadget->udc = udc; udc->started = false; mutex_lock(&udc_lock); list_add_tail(&udc->list, &udc_list); ret = device_add(&udc->dev); if (ret) goto err_unlist_udc; usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED); udc->vbus = true; /* pick up one of pending gadget drivers */ ret = check_pending_gadget_drivers(udc); if (ret) goto err_del_udc; mutex_unlock(&udc_lock); return 0; err_del_udc: flush_work(&gadget->work); device_del(&udc->dev); err_unlist_udc: list_del(&udc->list); mutex_unlock(&udc_lock); device_del(&gadget->dev); err_put_udc: put_device(&udc->dev); error: return ret; } EXPORT_SYMBOL_GPL(usb_add_gadget); /** * usb_add_gadget_udc_release - adds a new gadget to the udc class driver list * @parent: the parent device to this udc. Usually the controller driver's * device. * @gadget: the gadget to be added to the list. * @release: a gadget release function. * * Returns zero on success, negative errno otherwise. * Calls the gadget release function in the latter case. */ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget, void (*release)(struct device *dev)) { int ret; usb_initialize_gadget(parent, gadget, release); ret = usb_add_gadget(gadget); if (ret) usb_put_gadget(gadget); return ret; } EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release); /** * usb_get_gadget_udc_name - get the name of the first UDC controller * This functions returns the name of the first UDC controller in the system. * Please note that this interface is usefull only for legacy drivers which * assume that there is only one UDC controller in the system and they need to * get its name before initialization. There is no guarantee that the UDC * of the returned name will be still available, when gadget driver registers * itself. * * Returns pointer to string with UDC controller name on success, NULL * otherwise. Caller should kfree() returned string. */ char *usb_get_gadget_udc_name(void) { struct usb_udc *udc; char *name = NULL; /* For now we take the first available UDC */ mutex_lock(&udc_lock); list_for_each_entry(udc, &udc_list, list) { if (!udc->driver) { name = kstrdup(udc->gadget->name, GFP_KERNEL); break; } } mutex_unlock(&udc_lock); return name; } EXPORT_SYMBOL_GPL(usb_get_gadget_udc_name); /** * usb_add_gadget_udc - adds a new gadget to the udc class driver list * @parent: the parent device to this udc. Usually the controller * driver's device. * @gadget: the gadget to be added to the list * * Returns zero on success, negative errno otherwise. */ int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget) { return usb_add_gadget_udc_release(parent, gadget, NULL); } EXPORT_SYMBOL_GPL(usb_add_gadget_udc); static void usb_gadget_remove_driver(struct usb_udc *udc) { dev_dbg(&udc->dev, "unregistering UDC driver [%s]\n", udc->driver->function); mutex_lock(&connect_lock); usb_gadget_disconnect_locked(udc->gadget); usb_gadget_disable_async_callbacks(udc); if (udc->gadget->irq) synchronize_irq(udc->gadget->irq); mutex_unlock(&connect_lock); udc->driver->unbind(udc->gadget); mutex_lock(&connect_lock); usb_gadget_udc_stop_locked(udc); mutex_unlock(&connect_lock); udc->driver = NULL; udc->gadget->dev.driver = NULL; kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE); } /** * usb_del_gadget - deletes @udc from udc_list * @gadget: the gadget to be removed. * * This will call usb_gadget_unregister_driver() if * the @udc is still busy. * It will not do a final usb_put_gadget(). */ void usb_del_gadget(struct usb_gadget *gadget) { struct usb_udc *udc = gadget->udc; if (!udc) return; dev_vdbg(gadget->dev.parent, "unregistering gadget\n"); mutex_lock(&udc_lock); list_del(&udc->list); if (udc->driver) { struct usb_gadget_driver *driver = udc->driver; usb_gadget_remove_driver(udc); list_add(&driver->pending, &gadget_driver_pending_list); } mutex_unlock(&udc_lock); kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE); flush_work(&gadget->work); device_unregister(&udc->dev); device_del(&gadget->dev); } EXPORT_SYMBOL_GPL(usb_del_gadget); /** * usb_del_gadget_udc - deletes @udc from udc_list * @gadget: the gadget to be removed. * * Calls usb_del_gadget() and does a final usb_put_gadget(). */ void usb_del_gadget_udc(struct usb_gadget *gadget) { usb_del_gadget(gadget); usb_put_gadget(gadget); } EXPORT_SYMBOL_GPL(usb_del_gadget_udc); /* ------------------------------------------------------------------------- */ static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *driver) { int ret; dev_dbg(&udc->dev, "registering UDC driver [%s]\n", driver->function); udc->driver = driver; udc->gadget->dev.driver = &driver->driver; usb_gadget_udc_set_speed(udc, driver->max_speed); ret = driver->bind(udc->gadget, driver); if (ret) goto err1; mutex_lock(&connect_lock); ret = usb_gadget_udc_start_locked(udc); if (ret) { mutex_unlock(&connect_lock); driver->unbind(udc->gadget); goto err1; } usb_gadget_enable_async_callbacks(udc); usb_udc_connect_control_locked(udc); mutex_unlock(&connect_lock); kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE); return 0; err1: if (ret != -EISNAM) dev_err(&udc->dev, "failed to start %s: %d\n", udc->driver->function, ret); udc->driver = NULL; udc->gadget->dev.driver = NULL; return ret; } int usb_gadget_probe_driver(struct usb_gadget_driver *driver) { struct usb_udc *udc = NULL; int ret = -ENODEV; if (!driver || !driver->bind || !driver->setup) return -EINVAL; mutex_lock(&udc_lock); if (driver->udc_name) { list_for_each_entry(udc, &udc_list, list) { ret = strcmp(driver->udc_name, dev_name(&udc->dev)); if (!ret) break; } if (ret) ret = -ENODEV; else if (udc->driver) ret = -EBUSY; else goto found; } else { list_for_each_entry(udc, &udc_list, list) { /* For now we take the first one */ if (!udc->driver) goto found; } } if (!driver->match_existing_only) { list_add_tail(&driver->pending, &gadget_driver_pending_list); pr_info("udc-core: couldn't find an available UDC - added [%s] to list of pending drivers\n", driver->function); ret = 0; } mutex_unlock(&udc_lock); if (ret) pr_warn("udc-core: couldn't find an available UDC or it's busy\n"); return ret; found: ret = udc_bind_to_driver(udc, driver); mutex_unlock(&udc_lock); return ret; } EXPORT_SYMBOL_GPL(usb_gadget_probe_driver); int usb_gadget_unregister_driver(struct usb_gadget_driver *driver) { struct usb_udc *udc = NULL; int ret = -ENODEV; if (!driver || !driver->unbind) return -EINVAL; mutex_lock(&udc_lock); list_for_each_entry(udc, &udc_list, list) { if (udc->driver == driver) { usb_gadget_remove_driver(udc); usb_gadget_set_state(udc->gadget, USB_STATE_NOTATTACHED); /* Maybe there is someone waiting for this UDC? */ check_pending_gadget_drivers(udc); /* * For now we ignore bind errors as probably it's * not a valid reason to fail other's gadget unbind */ ret = 0; break; } } if (ret) { list_del(&driver->pending); ret = 0; } mutex_unlock(&udc_lock); return ret; } EXPORT_SYMBOL_GPL(usb_gadget_unregister_driver); /* ------------------------------------------------------------------------- */ static ssize_t srp_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) { struct usb_udc *udc = container_of(dev, struct usb_udc, dev); if (sysfs_streq(buf, "1")) usb_gadget_wakeup(udc->gadget); return n; } static DEVICE_ATTR_WO(srp); static ssize_t soft_connect_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) { struct usb_udc *udc = container_of(dev, struct usb_udc, dev); ssize_t ret; mutex_lock(&udc_lock); if (!udc->driver) { dev_err(dev, "soft-connect without a gadget driver\n"); ret = -EOPNOTSUPP; goto out; } if (sysfs_streq(buf, "connect")) { mutex_lock(&connect_lock); usb_gadget_udc_start_locked(udc); usb_gadget_connect_locked(udc->gadget); mutex_unlock(&connect_lock); } else if (sysfs_streq(buf, "disconnect")) { mutex_lock(&connect_lock); usb_gadget_disconnect_locked(udc->gadget); usb_gadget_udc_stop_locked(udc); mutex_unlock(&connect_lock); } else { dev_err(dev, "unsupported command '%s'\n", buf); ret = -EINVAL; goto out; } ret = n; out: mutex_unlock(&udc_lock); return ret; } static DEVICE_ATTR_WO(soft_connect); static ssize_t state_show(struct device *dev, struct device_attribute *attr, char *buf) { struct usb_udc *udc = container_of(dev, struct usb_udc, dev); struct usb_gadget *gadget = udc->gadget; return sprintf(buf, "%s\n", usb_state_string(gadget->state)); } static DEVICE_ATTR_RO(state); static ssize_t function_show(struct device *dev, struct device_attribute *attr, char *buf) { struct usb_udc *udc = container_of(dev, struct usb_udc, dev); struct usb_gadget_driver *drv = udc->driver; if (!drv || !drv->function) return 0; return scnprintf(buf, PAGE_SIZE, "%s\n", drv->function); } static DEVICE_ATTR_RO(function); #define USB_UDC_SPEED_ATTR(name, param) \ ssize_t name##_show(struct device *dev, \ struct device_attribute *attr, char *buf) \ { \ struct usb_udc *udc = container_of(dev, struct usb_udc, dev); \ return scnprintf(buf, PAGE_SIZE, "%s\n", \ usb_speed_string(udc->gadget->param)); \ } \ static DEVICE_ATTR_RO(name) static USB_UDC_SPEED_ATTR(current_speed, speed); static USB_UDC_SPEED_ATTR(maximum_speed, max_speed); #define USB_UDC_ATTR(name) \ ssize_t name##_show(struct device *dev, \ struct device_attribute *attr, char *buf) \ { \ struct usb_udc *udc = container_of(dev, struct usb_udc, dev); \ struct usb_gadget *gadget = udc->gadget; \ \ return scnprintf(buf, PAGE_SIZE, "%d\n", gadget->name); \ } \ static DEVICE_ATTR_RO(name) static USB_UDC_ATTR(is_otg); static USB_UDC_ATTR(is_a_peripheral); static USB_UDC_ATTR(b_hnp_enable); static USB_UDC_ATTR(a_hnp_support); static USB_UDC_ATTR(a_alt_hnp_support); static USB_UDC_ATTR(is_selfpowered); static struct attribute *usb_udc_attrs[] = { &dev_attr_srp.attr, &dev_attr_soft_connect.attr, &dev_attr_state.attr, &dev_attr_function.attr, &dev_attr_current_speed.attr, &dev_attr_maximum_speed.attr, &dev_attr_is_otg.attr, &dev_attr_is_a_peripheral.attr, &dev_attr_b_hnp_enable.attr, &dev_attr_a_hnp_support.attr, &dev_attr_a_alt_hnp_support.attr, &dev_attr_is_selfpowered.attr, NULL, }; static const struct attribute_group usb_udc_attr_group = { .attrs = usb_udc_attrs, }; static const struct attribute_group *usb_udc_attr_groups[] = { &usb_udc_attr_group, NULL, }; static int usb_udc_uevent(struct device *dev, struct kobj_uevent_env *env) { struct usb_udc *udc = container_of(dev, struct usb_udc, dev); int ret; ret = add_uevent_var(env, "USB_UDC_NAME=%s", udc->gadget->name); if (ret) { dev_err(dev, "failed to add uevent USB_UDC_NAME\n"); return ret; } if (udc->driver) { ret = add_uevent_var(env, "USB_UDC_DRIVER=%s", udc->driver->function); if (ret) { dev_err(dev, "failed to add uevent USB_UDC_DRIVER\n"); return ret; } } return 0; } static int __init usb_udc_init(void) { udc_class = class_create(THIS_MODULE, "udc"); if (IS_ERR(udc_class)) { pr_err("failed to create udc class --> %ld\n", PTR_ERR(udc_class)); return PTR_ERR(udc_class); } udc_class->dev_uevent = usb_udc_uevent; return 0; } subsys_initcall(usb_udc_init); static void __exit usb_udc_exit(void) { class_destroy(udc_class); } module_exit(usb_udc_exit); MODULE_DESCRIPTION("UDC Framework"); MODULE_AUTHOR("Felipe Balbi "); MODULE_LICENSE("GPL v2");