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-rw-r--r--drivers/usb/gadget/udc/core.c1877
1 files changed, 1877 insertions, 0 deletions
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
new file mode 100644
index 000000000..c40f2ecbe
--- /dev/null
+++ b/drivers/usb/gadget/udc/core.c
@@ -0,0 +1,1877 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * udc.c - Core UDC Framework
+ *
+ * Copyright (C) 2010 Texas Instruments
+ * Author: Felipe Balbi <balbi@ti.com>
+ */
+
+#define pr_fmt(fmt) "UDC core: " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/idr.h>
+#include <linux/err.h>
+#include <linux/dma-mapping.h>
+#include <linux/sched/task_stack.h>
+#include <linux/workqueue.h>
+
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+#include <linux/usb.h>
+
+#include "trace.h"
+
+static DEFINE_IDA(gadget_id_numbers);
+
+static struct bus_type gadget_bus_type;
+
+/**
+ * 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.
+ * @allow_connect: Indicates whether UDC is allowed to be pulled up.
+ * Set/cleared by gadget_(un)bind_driver() after gadget driver is bound or
+ * unbound.
+ * @vbus_work: work routine to handle VBUS status change notifications.
+ * @connect_lock: protects udc->started, gadget->connect,
+ * gadget->allow_connect and gadget->deactivate. The routines
+ * usb_gadget_connect_locked(), usb_gadget_disconnect_locked(),
+ * usb_udc_connect_control_locked(), usb_gadget_udc_start_locked() and
+ * usb_gadget_udc_stop_locked() are called with this lock held.
+ *
+ * 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;
+ bool allow_connect;
+ struct work_struct vbus_work;
+ struct mutex connect_lock;
+};
+
+static struct class *udc_class;
+static LIST_HEAD(udc_list);
+
+/* Protects udc_list, udc->driver, driver->is_bound, and related calls */
+static DEFINE_MUTEX(udc_lock);
+
+/* ------------------------------------------------------------------------- */
+
+/**
+ * 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);
+
+static int usb_gadget_connect_locked(struct usb_gadget *gadget)
+ __must_hold(&gadget->udc->connect_lock)
+{
+ int ret = 0;
+
+ if (!gadget->ops->pullup) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+
+ if (gadget->deactivated || !gadget->udc->allow_connect || !gadget->udc->started) {
+ /*
+ * If the gadget isn't usable (because it is deactivated,
+ * unbound, or not yet started), we only save the new state.
+ * The gadget will be connected automatically when it is
+ * activated/bound/started.
+ */
+ 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(&gadget->udc->connect_lock);
+ ret = usb_gadget_connect_locked(gadget);
+ mutex_unlock(&gadget->udc->connect_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(usb_gadget_connect);
+
+static int usb_gadget_disconnect_locked(struct usb_gadget *gadget)
+ __must_hold(&gadget->udc->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.
+ */
+ gadget->connected = false;
+ goto out;
+ }
+
+ ret = gadget->ops->pullup(gadget, 0);
+ if (!ret)
+ gadget->connected = 0;
+
+ mutex_lock(&udc_lock);
+ if (gadget->udc->driver)
+ gadget->udc->driver->disconnect(gadget);
+ mutex_unlock(&udc_lock);
+
+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(&gadget->udc->connect_lock);
+ ret = usb_gadget_disconnect_locked(gadget);
+ mutex_unlock(&gadget->udc->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;
+
+ mutex_lock(&gadget->udc->connect_lock);
+ if (gadget->deactivated)
+ goto unlock;
+
+ 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(&gadget->udc->connect_lock);
+ 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;
+
+ mutex_lock(&gadget->udc->connect_lock);
+ if (!gadget->deactivated)
+ goto unlock;
+
+ 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);
+
+unlock:
+ mutex_unlock(&gadget->udc->connect_lock);
+ 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
+ *
+ * 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(&udc->connect_lock)
+{
+ if (udc->vbus)
+ usb_gadget_connect_locked(udc->gadget);
+ else
+ usb_gadget_disconnect_locked(udc->gadget);
+}
+
+static void vbus_event_work(struct work_struct *work)
+{
+ struct usb_udc *udc = container_of(work, struct usb_udc, vbus_work);
+
+ mutex_lock(&udc->connect_lock);
+ usb_udc_connect_control_locked(udc);
+ mutex_unlock(&udc->connect_lock);
+}
+
+/**
+ * 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.
+ *
+ * This function can be invoked from interrupt context by irq handlers of
+ * the gadget drivers, however, usb_udc_connect_control() has to run in
+ * non-atomic context due to the following:
+ * a. Some of the gadget driver implementations expect the ->pullup
+ * callback to be invoked in non-atomic context.
+ * b. usb_gadget_disconnect() acquires udc_lock which is a mutex.
+ * Hence offload invocation of usb_udc_connect_control() to workqueue.
+ */
+void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status)
+{
+ struct usb_udc *udc = gadget->udc;
+
+ if (udc) {
+ udc->vbus = status;
+ schedule_work(&udc->vbus_work);
+ }
+}
+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(&udc->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(&udc->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__);
+}
+
+/**
+ * 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.
+ */
+void usb_initialize_gadget(struct device *parent, struct usb_gadget *gadget,
+ void (*release)(struct device *dev))
+{
+ 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);
+ gadget->dev.bus = &gadget_bus_type;
+}
+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;
+
+ udc->gadget = gadget;
+ gadget->udc = udc;
+ mutex_init(&udc->connect_lock);
+
+ udc->started = false;
+
+ mutex_lock(&udc_lock);
+ list_add_tail(&udc->list, &udc_list);
+ mutex_unlock(&udc_lock);
+ INIT_WORK(&udc->vbus_work, vbus_event_work);
+
+ ret = device_add(&udc->dev);
+ if (ret)
+ goto err_unlist_udc;
+
+ usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
+ udc->vbus = true;
+
+ ret = ida_alloc(&gadget_id_numbers, GFP_KERNEL);
+ if (ret < 0)
+ goto err_del_udc;
+ gadget->id_number = ret;
+ dev_set_name(&gadget->dev, "gadget.%d", ret);
+
+ ret = device_add(&gadget->dev);
+ if (ret)
+ goto err_free_id;
+
+ return 0;
+
+ err_free_id:
+ ida_free(&gadget_id_numbers, gadget->id_number);
+
+ err_del_udc:
+ flush_work(&gadget->work);
+ device_del(&udc->dev);
+
+ err_unlist_udc:
+ mutex_lock(&udc_lock);
+ list_del(&udc->list);
+ mutex_unlock(&udc_lock);
+
+ 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);
+
+/**
+ * usb_del_gadget - deletes a gadget and unregisters its udc
+ * @gadget: the gadget to be deleted.
+ *
+ * This will unbind @gadget, if it is bound.
+ * 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);
+ mutex_unlock(&udc_lock);
+
+ kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
+ flush_work(&gadget->work);
+ device_del(&gadget->dev);
+ ida_free(&gadget_id_numbers, gadget->id_number);
+ cancel_work_sync(&udc->vbus_work);
+ device_unregister(&udc->dev);
+}
+EXPORT_SYMBOL_GPL(usb_del_gadget);
+
+/**
+ * usb_del_gadget_udc - unregisters a gadget
+ * @gadget: the gadget to be unregistered.
+ *
+ * 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 gadget_match_driver(struct device *dev, struct device_driver *drv)
+{
+ struct usb_gadget *gadget = dev_to_usb_gadget(dev);
+ struct usb_udc *udc = gadget->udc;
+ struct usb_gadget_driver *driver = container_of(drv,
+ struct usb_gadget_driver, driver);
+
+ /* If the driver specifies a udc_name, it must match the UDC's name */
+ if (driver->udc_name &&
+ strcmp(driver->udc_name, dev_name(&udc->dev)) != 0)
+ return 0;
+
+ /* If the driver is already bound to a gadget, it doesn't match */
+ if (driver->is_bound)
+ return 0;
+
+ /* Otherwise any gadget driver matches any UDC */
+ return 1;
+}
+
+static int gadget_bind_driver(struct device *dev)
+{
+ struct usb_gadget *gadget = dev_to_usb_gadget(dev);
+ struct usb_udc *udc = gadget->udc;
+ struct usb_gadget_driver *driver = container_of(dev->driver,
+ struct usb_gadget_driver, driver);
+ int ret = 0;
+
+ mutex_lock(&udc_lock);
+ if (driver->is_bound) {
+ mutex_unlock(&udc_lock);
+ return -ENXIO; /* Driver binds to only one gadget */
+ }
+ driver->is_bound = true;
+ udc->driver = driver;
+ mutex_unlock(&udc_lock);
+
+ dev_dbg(&udc->dev, "binding gadget driver [%s]\n", driver->function);
+
+ usb_gadget_udc_set_speed(udc, driver->max_speed);
+
+ ret = driver->bind(udc->gadget, driver);
+ if (ret)
+ goto err_bind;
+
+ mutex_lock(&udc->connect_lock);
+ ret = usb_gadget_udc_start_locked(udc);
+ if (ret) {
+ mutex_unlock(&udc->connect_lock);
+ goto err_start;
+ }
+ usb_gadget_enable_async_callbacks(udc);
+ udc->allow_connect = true;
+ usb_udc_connect_control_locked(udc);
+ mutex_unlock(&udc->connect_lock);
+
+ kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
+ return 0;
+
+ err_start:
+ driver->unbind(udc->gadget);
+
+ err_bind:
+ if (ret != -EISNAM)
+ dev_err(&udc->dev, "failed to start %s: %d\n",
+ driver->function, ret);
+
+ mutex_lock(&udc_lock);
+ udc->driver = NULL;
+ driver->is_bound = false;
+ mutex_unlock(&udc_lock);
+
+ return ret;
+}
+
+static void gadget_unbind_driver(struct device *dev)
+{
+ struct usb_gadget *gadget = dev_to_usb_gadget(dev);
+ struct usb_udc *udc = gadget->udc;
+ struct usb_gadget_driver *driver = udc->driver;
+
+ dev_dbg(&udc->dev, "unbinding gadget driver [%s]\n", driver->function);
+
+ udc->allow_connect = false;
+ cancel_work_sync(&udc->vbus_work);
+ mutex_lock(&udc->connect_lock);
+ usb_gadget_disconnect_locked(gadget);
+ usb_gadget_disable_async_callbacks(udc);
+ if (gadget->irq)
+ synchronize_irq(gadget->irq);
+ mutex_unlock(&udc->connect_lock);
+
+ udc->driver->unbind(gadget);
+
+ mutex_lock(&udc->connect_lock);
+ usb_gadget_udc_stop_locked(udc);
+ mutex_unlock(&udc->connect_lock);
+
+ mutex_lock(&udc_lock);
+ driver->is_bound = false;
+ udc->driver = NULL;
+ mutex_unlock(&udc_lock);
+
+ kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
+}
+
+/* ------------------------------------------------------------------------- */
+
+int usb_gadget_register_driver_owner(struct usb_gadget_driver *driver,
+ struct module *owner, const char *mod_name)
+{
+ int ret;
+
+ if (!driver || !driver->bind || !driver->setup)
+ return -EINVAL;
+
+ driver->driver.bus = &gadget_bus_type;
+ driver->driver.owner = owner;
+ driver->driver.mod_name = mod_name;
+ ret = driver_register(&driver->driver);
+ if (ret) {
+ pr_warn("%s: driver registration failed: %d\n",
+ driver->function, ret);
+ return ret;
+ }
+
+ mutex_lock(&udc_lock);
+ if (!driver->is_bound) {
+ if (driver->match_existing_only) {
+ pr_warn("%s: couldn't find an available UDC or it's busy\n",
+ driver->function);
+ ret = -EBUSY;
+ } else {
+ pr_info("%s: couldn't find an available UDC\n",
+ driver->function);
+ ret = 0;
+ }
+ }
+ mutex_unlock(&udc_lock);
+
+ if (ret)
+ driver_unregister(&driver->driver);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(usb_gadget_register_driver_owner);
+
+int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
+{
+ if (!driver || !driver->unbind)
+ return -EINVAL;
+
+ driver_unregister(&driver->driver);
+ return 0;
+}
+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;
+
+ device_lock(&udc->gadget->dev);
+ if (!udc->driver) {
+ dev_err(dev, "soft-connect without a gadget driver\n");
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+
+ if (sysfs_streq(buf, "connect")) {
+ mutex_lock(&udc->connect_lock);
+ usb_gadget_udc_start_locked(udc);
+ usb_gadget_connect_locked(udc->gadget);
+ mutex_unlock(&udc->connect_lock);
+ } else if (sysfs_streq(buf, "disconnect")) {
+ mutex_lock(&udc->connect_lock);
+ usb_gadget_disconnect_locked(udc->gadget);
+ usb_gadget_udc_stop_locked(udc);
+ mutex_unlock(&udc->connect_lock);
+ } else {
+ dev_err(dev, "unsupported command '%s'\n", buf);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = n;
+out:
+ device_unlock(&udc->gadget->dev);
+ 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;
+ int rc = 0;
+
+ mutex_lock(&udc_lock);
+ drv = udc->driver;
+ if (drv && drv->function)
+ rc = scnprintf(buf, PAGE_SIZE, "%s\n", drv->function);
+ mutex_unlock(&udc_lock);
+ return rc;
+}
+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;
+ }
+
+ mutex_lock(&udc_lock);
+ if (udc->driver)
+ ret = add_uevent_var(env, "USB_UDC_DRIVER=%s",
+ udc->driver->function);
+ mutex_unlock(&udc_lock);
+ if (ret) {
+ dev_err(dev, "failed to add uevent USB_UDC_DRIVER\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static struct bus_type gadget_bus_type = {
+ .name = "gadget",
+ .probe = gadget_bind_driver,
+ .remove = gadget_unbind_driver,
+ .match = gadget_match_driver,
+};
+
+static int __init usb_udc_init(void)
+{
+ int rc;
+
+ 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;
+
+ rc = bus_register(&gadget_bus_type);
+ if (rc)
+ class_destroy(udc_class);
+ return rc;
+}
+subsys_initcall(usb_udc_init);
+
+static void __exit usb_udc_exit(void)
+{
+ bus_unregister(&gadget_bus_type);
+ class_destroy(udc_class);
+}
+module_exit(usb_udc_exit);
+
+MODULE_DESCRIPTION("UDC Framework");
+MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
+MODULE_LICENSE("GPL v2");