Re: [balbi-usb:testing/next 64/67] otg.c:undefined reference to `usb_gadget_vbus_disconnect'

[Peter Chen <hzpeterchen-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

On Mon, Jun 13, 2016 at 09:01:55AM +0300, Felipe Balbi wrote:
> Felipe Balbi <felipe.balbi-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> writes:
> 
> Here's an updated version:
> 
> From d45bdfafc3143dc7acc9d71131807d3e30ab7bcd Mon Sep 17 00:00:00 2001
> From: Felipe Balbi <felipe.balbi-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> Date: Tue, 31 May 2016 13:07:47 +0300
> Subject: [PATCH] usb: gadget: move gadget API functions to udc-core
> 
> instead of defining all functions as static inlines,
> let's move them to udc-core and export them with
> EXPORT_SYMBOL_GPL, that way we can make sure that
> only GPL drivers will use them.
> 
> As a side effect, it'll be nicer to add tracepoints
> to the gadget API.
> 
> While at that, also fix Kconfig dependencies to
> avoid randconfig build failures.
> 
> Signed-off-by: Felipe Balbi <felipe.balbi-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>

Acked-by: Peter Chen <peter.chen-3arQi8VN3Tc@public.gmane.org>

> ---
>  drivers/phy/Kconfig               |   1 +
>  drivers/power/Kconfig             |   1 +
>  drivers/usb/gadget/udc/udc-core.c | 573 +++++++++++++++++++++++++++++++++++++
>  drivers/usb/host/Kconfig          |   2 +-
>  drivers/usb/phy/Kconfig           |  11 +-
>  include/linux/usb/gadget.h        | 585 ++++----------------------------------
>  6 files changed, 645 insertions(+), 528 deletions(-)
> 
> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
> index b869b98835f4..8d1cfb7f3ea2 100644
> --- a/drivers/phy/Kconfig
> +++ b/drivers/phy/Kconfig
> @@ -176,6 +176,7 @@ config TWL4030_USB
>  	tristate "TWL4030 USB Transceiver Driver"
>  	depends on TWL4030_CORE && REGULATOR_TWL4030 && USB_MUSB_OMAP2PLUS
>  	depends on USB_SUPPORT
> +	depends on USB_GADGET || !USB_GADGET # if USB_GADGET=m, this can't 'y'
>  	select GENERIC_PHY
>  	select USB_PHY
>  	help
> diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
> index 421770ddafa3..0f11a0f4c369 100644
> --- a/drivers/power/Kconfig
> +++ b/drivers/power/Kconfig
> @@ -309,6 +309,7 @@ config BATTERY_RX51
>  config CHARGER_ISP1704
>  	tristate "ISP1704 USB Charger Detection"
>  	depends on USB_PHY
> +	depends on USB_GADGET || !USB_GADGET # if USB_GADGET=m, this can't be 'y'
>  	help
>  	  Say Y to enable support for USB Charger Detection with
>  	  ISP1707/ISP1704 USB transceivers.
> diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c
> index 6e8300d6a737..d2f28bb6dbda 100644
> --- a/drivers/usb/gadget/udc/udc-core.c
> +++ b/drivers/usb/gadget/udc/udc-core.c
> @@ -59,6 +59,579 @@ static int udc_bind_to_driver(struct usb_udc *udc,
>  
>  /* ------------------------------------------------------------------------- */
>  
> +/**
> + * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
> + * @ep:the endpoint being configured
> + * @maxpacket_limit:value of maximum packet size limit
> + *
> + * This function should be used only in UDC drivers to initialize endpoint
> + * (usually in probe function).
> + */
> +void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
> +					      unsigned maxpacket_limit)
> +{
> +	ep->maxpacket_limit = maxpacket_limit;
> +	ep->maxpacket = maxpacket_limit;
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_set_maxpacket_limit);
> +
> +/**
> + * usb_ep_enable - configure endpoint, making it usable
> + * @ep:the endpoint being configured.  may not be the endpoint named "ep0".
> + *	drivers discover endpoints through the ep_list of a usb_gadget.
> + *
> + * When configurations are set, or when interface settings change, the driver
> + * will enable or disable the relevant endpoints.  while it is enabled, an
> + * endpoint may be used for i/o until the driver receives a disconnect() from
> + * the host or until the endpoint is disabled.
> + *
> + * the ep0 implementation (which calls this routine) must ensure that the
> + * hardware capabilities of each endpoint match the descriptor provided
> + * for it.  for example, an endpoint named "ep2in-bulk" would be usable
> + * for interrupt transfers as well as bulk, but it likely couldn't be used
> + * for iso transfers or for endpoint 14.  some endpoints are fully
> + * configurable, with more generic names like "ep-a".  (remember that for
> + * USB, "in" means "towards the USB master".)
> + *
> + * returns zero, or a negative error code.
> + */
> +int usb_ep_enable(struct usb_ep *ep)
> +{
> +	int ret;
> +
> +	if (ep->enabled)
> +		return 0;
> +
> +	ret = ep->ops->enable(ep, ep->desc);
> +	if (ret)
> +		return ret;
> +
> +	ep->enabled = true;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_enable);
> +
> +/**
> + * usb_ep_disable - endpoint is no longer usable
> + * @ep:the endpoint being unconfigured.  may not be the endpoint named "ep0".
> + *
> + * no other task may be using this endpoint when this is called.
> + * any pending and uncompleted requests will complete with status
> + * indicating disconnect (-ESHUTDOWN) before this call returns.
> + * gadget drivers must call usb_ep_enable() again before queueing
> + * requests to the endpoint.
> + *
> + * returns zero, or a negative error code.
> + */
> +int usb_ep_disable(struct usb_ep *ep)
> +{
> +	int ret;
> +
> +	if (!ep->enabled)
> +		return 0;
> +
> +	ret = ep->ops->disable(ep);
> +	if (ret)
> +		return ret;
> +
> +	ep->enabled = false;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_disable);
> +
> +/**
> + * usb_ep_alloc_request - allocate a request object to use with this endpoint
> + * @ep:the endpoint to be used with with the request
> + * @gfp_flags:GFP_* flags to use
> + *
> + * Request objects must be allocated with this call, since they normally
> + * need controller-specific setup and may even need endpoint-specific
> + * resources such as allocation of DMA descriptors.
> + * Requests may be submitted with usb_ep_queue(), and receive a single
> + * completion callback.  Free requests with usb_ep_free_request(), when
> + * they are no longer needed.
> + *
> + * Returns the request, or null if one could not be allocated.
> + */
> +struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
> +						       gfp_t gfp_flags)
> +{
> +	return ep->ops->alloc_request(ep, gfp_flags);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_alloc_request);
> +
> +/**
> + * usb_ep_free_request - frees a request object
> + * @ep:the endpoint associated with the request
> + * @req:the request being freed
> + *
> + * Reverses the effect of usb_ep_alloc_request().
> + * Caller guarantees the request is not queued, and that it will
> + * no longer be requeued (or otherwise used).
> + */
> +void usb_ep_free_request(struct usb_ep *ep,
> +				       struct usb_request *req)
> +{
> +	ep->ops->free_request(ep, req);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_free_request);
> +
> +/**
> + * usb_ep_queue - queues (submits) an I/O request to an endpoint.
> + * @ep:the endpoint associated with the request
> + * @req:the request being submitted
> + * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
> + *	pre-allocate all necessary memory with the request.
> + *
> + * This tells the device controller to perform the specified request through
> + * that endpoint (reading or writing a buffer).  When the request completes,
> + * including being canceled by usb_ep_dequeue(), the request's completion
> + * routine is called to return the request to the driver.  Any endpoint
> + * (except control endpoints like ep0) may have more than one transfer
> + * request queued; they complete in FIFO order.  Once a gadget driver
> + * submits a request, that request may not be examined or modified until it
> + * is given back to that driver through the completion callback.
> + *
> + * Each request is turned into one or more packets.  The controller driver
> + * never merges adjacent requests into the same packet.  OUT transfers
> + * will sometimes use data that's already buffered in the hardware.
> + * Drivers can rely on the fact that the first byte of the request's buffer
> + * always corresponds to the first byte of some USB packet, for both
> + * IN and OUT transfers.
> + *
> + * Bulk endpoints can queue any amount of data; the transfer is packetized
> + * automatically.  The last packet will be short if the request doesn't fill it
> + * out completely.  Zero length packets (ZLPs) should be avoided in portable
> + * protocols since not all usb hardware can successfully handle zero length
> + * packets.  (ZLPs may be explicitly written, and may be implicitly written if
> + * the request 'zero' flag is set.)  Bulk endpoints may also be used
> + * for interrupt transfers; but the reverse is not true, and some endpoints
> + * won't support every interrupt transfer.  (Such as 768 byte packets.)
> + *
> + * Interrupt-only endpoints are less functional than bulk endpoints, for
> + * example by not supporting queueing or not handling buffers that are
> + * larger than the endpoint's maxpacket size.  They may also treat data
> + * toggle differently.
> + *
> + * Control endpoints ... after getting a setup() callback, the driver queues
> + * one response (even if it would be zero length).  That enables the
> + * status ack, after transferring data as specified in the response.  Setup
> + * functions may return negative error codes to generate protocol stalls.
> + * (Note that some USB device controllers disallow protocol stall responses
> + * in some cases.)  When control responses are deferred (the response is
> + * written after the setup callback returns), then usb_ep_set_halt() may be
> + * used on ep0 to trigger protocol stalls.  Depending on the controller,
> + * it may not be possible to trigger a status-stage protocol stall when the
> + * data stage is over, that is, from within the response's completion
> + * routine.
> + *
> + * For periodic endpoints, like interrupt or isochronous ones, the usb host
> + * arranges to poll once per interval, and the gadget driver usually will
> + * have queued some data to transfer at that time.
> + *
> + * Returns zero, or a negative error code.  Endpoints that are not enabled
> + * report errors; errors will also be
> + * reported when the usb peripheral is disconnected.
> + */
> +int usb_ep_queue(struct usb_ep *ep,
> +			       struct usb_request *req, gfp_t gfp_flags)
> +{
> +	if (WARN_ON_ONCE(!ep->enabled && ep->address))
> +		return -ESHUTDOWN;
> +
> +	return ep->ops->queue(ep, req, gfp_flags);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_queue);
> +
> +/**
> + * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
> + * @ep:the endpoint associated with the request
> + * @req:the request being canceled
> + *
> + * If the request is still active on the endpoint, it is dequeued and its
> + * completion routine is called (with status -ECONNRESET); else a negative
> + * error code is returned. This is guaranteed to happen before the call to
> + * usb_ep_dequeue() returns.
> + *
> + * Note that some hardware can't clear out write fifos (to unlink the request
> + * at the head of the queue) except as part of disconnecting from usb. Such
> + * restrictions prevent drivers from supporting configuration changes,
> + * even to configuration zero (a "chapter 9" requirement).
> + */
> +int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
> +{
> +	return ep->ops->dequeue(ep, req);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_dequeue);
> +
> +/**
> + * usb_ep_set_halt - sets the endpoint halt feature.
> + * @ep: the non-isochronous endpoint being stalled
> + *
> + * Use this to stall an endpoint, perhaps as an error report.
> + * Except for control endpoints,
> + * the endpoint stays halted (will not stream any data) until the host
> + * clears this feature; drivers may need to empty the endpoint's request
> + * queue first, to make sure no inappropriate transfers happen.
> + *
> + * Note that while an endpoint CLEAR_FEATURE will be invisible to the
> + * gadget driver, a SET_INTERFACE will not be.  To reset endpoints for the
> + * current altsetting, see usb_ep_clear_halt().  When switching altsettings,
> + * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
> + *
> + * Returns zero, or a negative error code.  On success, this call sets
> + * underlying hardware state that blocks data transfers.
> + * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
> + * transfer requests are still queued, or if the controller hardware
> + * (usually a FIFO) still holds bytes that the host hasn't collected.
> + */
> +int usb_ep_set_halt(struct usb_ep *ep)
> +{
> +	return ep->ops->set_halt(ep, 1);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_set_halt);
> +
> +/**
> + * usb_ep_clear_halt - clears endpoint halt, and resets toggle
> + * @ep:the bulk or interrupt endpoint being reset
> + *
> + * Use this when responding to the standard usb "set interface" request,
> + * for endpoints that aren't reconfigured, after clearing any other state
> + * in the endpoint's i/o queue.
> + *
> + * Returns zero, or a negative error code.  On success, this call clears
> + * the underlying hardware state reflecting endpoint halt and data toggle.
> + * Note that some hardware can't support this request (like pxa2xx_udc),
> + * and accordingly can't correctly implement interface altsettings.
> + */
> +int usb_ep_clear_halt(struct usb_ep *ep)
> +{
> +	return ep->ops->set_halt(ep, 0);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_clear_halt);
> +
> +/**
> + * usb_ep_set_wedge - sets the halt feature and ignores clear requests
> + * @ep: the endpoint being wedged
> + *
> + * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT)
> + * requests. If the gadget driver clears the halt status, it will
> + * automatically unwedge the endpoint.
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_ep_set_wedge(struct usb_ep *ep)
> +{
> +	if (ep->ops->set_wedge)
> +		return ep->ops->set_wedge(ep);
> +	else
> +		return ep->ops->set_halt(ep, 1);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_set_wedge);
> +
> +/**
> + * usb_ep_fifo_status - returns number of bytes in fifo, or error
> + * @ep: the endpoint whose fifo status is being checked.
> + *
> + * FIFO endpoints may have "unclaimed data" in them in certain cases,
> + * such as after aborted transfers.  Hosts may not have collected all
> + * the IN data written by the gadget driver (and reported by a request
> + * completion).  The gadget driver may not have collected all the data
> + * written OUT to it by the host.  Drivers that need precise handling for
> + * fault reporting or recovery may need to use this call.
> + *
> + * This returns the number of such bytes in the fifo, or a negative
> + * errno if the endpoint doesn't use a FIFO or doesn't support such
> + * precise handling.
> + */
> +int usb_ep_fifo_status(struct usb_ep *ep)
> +{
> +	if (ep->ops->fifo_status)
> +		return ep->ops->fifo_status(ep);
> +	else
> +		return -EOPNOTSUPP;
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_fifo_status);
> +
> +/**
> + * usb_ep_fifo_flush - flushes contents of a fifo
> + * @ep: the endpoint whose fifo is being flushed.
> + *
> + * This call may be used to flush the "unclaimed data" that may exist in
> + * an endpoint fifo after abnormal transaction terminations.  The call
> + * must never be used except when endpoint is not being used for any
> + * protocol translation.
> + */
> +void usb_ep_fifo_flush(struct usb_ep *ep)
> +{
> +	if (ep->ops->fifo_flush)
> +		ep->ops->fifo_flush(ep);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_fifo_flush);
> +
> +/* ------------------------------------------------------------------------- */
> +
> +/**
> + * usb_gadget_frame_number - returns the current frame number
> + * @gadget: controller that reports the frame number
> + *
> + * Returns the usb frame number, normally eleven bits from a SOF packet,
> + * or negative errno if this device doesn't support this capability.
> + */
> +int usb_gadget_frame_number(struct usb_gadget *gadget)
> +{
> +	return gadget->ops->get_frame(gadget);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_frame_number);
> +
> +/**
> + * usb_gadget_wakeup - tries to wake up the host connected to this gadget
> + * @gadget: controller used to wake up the host
> + *
> + * Returns zero on success, else negative error code if the hardware
> + * doesn't support such attempts, or its support has not been enabled
> + * by the usb host.  Drivers must return device descriptors that report
> + * their ability to support this, or hosts won't enable it.
> + *
> + * This may also try to use SRP to wake the host and start enumeration,
> + * even if OTG isn't otherwise in use.  OTG devices may also start
> + * remote wakeup even when hosts don't explicitly enable it.
> + */
> +int usb_gadget_wakeup(struct usb_gadget *gadget)
> +{
> +	if (!gadget->ops->wakeup)
> +		return -EOPNOTSUPP;
> +	return gadget->ops->wakeup(gadget);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_wakeup);
> +
> +/**
> + * usb_gadget_set_selfpowered - sets the device selfpowered feature.
> + * @gadget:the device being declared as self-powered
> + *
> + * this affects the device status reported by the hardware driver
> + * to reflect that it now has a local power supply.
> + *
> + * returns zero on success, else negative errno.
> + */
> +int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
> +{
> +	if (!gadget->ops->set_selfpowered)
> +		return -EOPNOTSUPP;
> +	return gadget->ops->set_selfpowered(gadget, 1);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_set_selfpowered);
> +
> +/**
> + * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
> + * @gadget:the device being declared as bus-powered
> + *
> + * this affects the device status reported by the hardware driver.
> + * some hardware may not support bus-powered operation, in which
> + * case this feature's value can never change.
> + *
> + * returns zero on success, else negative errno.
> + */
> +int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
> +{
> +	if (!gadget->ops->set_selfpowered)
> +		return -EOPNOTSUPP;
> +	return gadget->ops->set_selfpowered(gadget, 0);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_clear_selfpowered);
> +
> +/**
> + * usb_gadget_vbus_connect - Notify controller that VBUS is powered
> + * @gadget:The device which now has VBUS power.
> + * Context: can sleep
> + *
> + * This call is used by a driver for an external transceiver (or GPIO)
> + * that detects a VBUS power session starting.  Common responses include
> + * resuming the controller, activating the D+ (or D-) pullup to let the
> + * host detect that a USB device is attached, and starting to draw power
> + * (8mA or possibly more, especially after SET_CONFIGURATION).
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_vbus_connect(struct usb_gadget *gadget)
> +{
> +	if (!gadget->ops->vbus_session)
> +		return -EOPNOTSUPP;
> +	return gadget->ops->vbus_session(gadget, 1);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_vbus_connect);
> +
> +/**
> + * usb_gadget_vbus_draw - constrain controller's VBUS power usage
> + * @gadget:The device whose VBUS usage is being described
> + * @mA:How much current to draw, in milliAmperes.  This should be twice
> + *	the value listed in the configuration descriptor bMaxPower field.
> + *
> + * This call is used by gadget drivers during SET_CONFIGURATION calls,
> + * reporting how much power the device may consume.  For example, this
> + * could affect how quickly batteries are recharged.
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
> +{
> +	if (!gadget->ops->vbus_draw)
> +		return -EOPNOTSUPP;
> +	return gadget->ops->vbus_draw(gadget, mA);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_vbus_draw);
> +
> +/**
> + * usb_gadget_vbus_disconnect - notify controller about VBUS session end
> + * @gadget:the device whose VBUS supply is being described
> + * Context: can sleep
> + *
> + * This call is used by a driver for an external transceiver (or GPIO)
> + * that detects a VBUS power session ending.  Common responses include
> + * reversing everything done in usb_gadget_vbus_connect().
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
> +{
> +	if (!gadget->ops->vbus_session)
> +		return -EOPNOTSUPP;
> +	return gadget->ops->vbus_session(gadget, 0);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_vbus_disconnect);
> +
> +/**
> + * usb_gadget_connect - software-controlled connect to USB host
> + * @gadget:the peripheral being connected
> + *
> + * Enables the D+ (or potentially D-) pullup.  The host will start
> + * enumerating this gadget when the pullup is active and a VBUS session
> + * is active (the link is powered).  This pullup is always enabled unless
> + * usb_gadget_disconnect() has been used to disable it.
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_connect(struct usb_gadget *gadget)
> +{
> +	int ret;
> +
> +	if (!gadget->ops->pullup)
> +		return -EOPNOTSUPP;
> +
> +	if (gadget->deactivated) {
> +		/*
> +		 * If gadget is deactivated we only save new state.
> +		 * Gadget will be connected automatically after activation.
> +		 */
> +		gadget->connected = true;
> +		return 0;
> +	}
> +
> +	ret = gadget->ops->pullup(gadget, 1);
> +	if (!ret)
> +		gadget->connected = 1;
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_connect);
> +
> +/**
> + * usb_gadget_disconnect - software-controlled disconnect from USB host
> + * @gadget:the peripheral being disconnected
> + *
> + * Disables the D+ (or potentially D-) pullup, which the host may see
> + * as a disconnect (when a VBUS session is active).  Not all systems
> + * support software pullup controls.
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_disconnect(struct usb_gadget *gadget)
> +{
> +	int ret;
> +
> +	if (!gadget->ops->pullup)
> +		return -EOPNOTSUPP;
> +
> +	if (gadget->deactivated) {
> +		/*
> +		 * If gadget is deactivated we only save new state.
> +		 * Gadget will stay disconnected after activation.
> +		 */
> +		gadget->connected = false;
> +		return 0;
> +	}
> +
> +	ret = gadget->ops->pullup(gadget, 0);
> +	if (!ret)
> +		gadget->connected = 0;
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_disconnect);
> +
> +/**
> + * usb_gadget_deactivate - deactivate function which is not ready to work
> + * @gadget: the peripheral being deactivated
> + *
> + * This routine may be used during the gadget driver bind() call to prevent
> + * the peripheral from ever being visible to the USB host, unless later
> + * usb_gadget_activate() is called.  For example, user mode components may
> + * need to be activated before the system can talk to hosts.
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_deactivate(struct usb_gadget *gadget)
> +{
> +	int ret;
> +
> +	if (gadget->deactivated)
> +		return 0;
> +
> +	if (gadget->connected) {
> +		ret = usb_gadget_disconnect(gadget);
> +		if (ret)
> +			return ret;
> +		/*
> +		 * If gadget was being connected before deactivation, we want
> +		 * to reconnect it in usb_gadget_activate().
> +		 */
> +		gadget->connected = true;
> +	}
> +	gadget->deactivated = true;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_deactivate);
> +
> +/**
> + * usb_gadget_activate - activate function which is not ready to work
> + * @gadget: the peripheral being activated
> + *
> + * This routine activates gadget which was previously deactivated with
> + * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed.
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_activate(struct usb_gadget *gadget)
> +{
> +	if (!gadget->deactivated)
> +		return 0;
> +
> +	gadget->deactivated = false;
> +
> +	/*
> +	 * If gadget has been connected before deactivation, or became connected
> +	 * while it was being deactivated, we call usb_gadget_connect().
> +	 */
> +	if (gadget->connected)
> +		return usb_gadget_connect(gadget);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_activate);
> +
> +/* ------------------------------------------------------------------------- */
> +
>  #ifdef	CONFIG_HAS_DMA
>  
>  int usb_gadget_map_request_by_dev(struct device *dev,
> diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
> index d8f5674809e8..2e710a4cca52 100644
> --- a/drivers/usb/host/Kconfig
> +++ b/drivers/usb/host/Kconfig
> @@ -180,7 +180,7 @@ config USB_EHCI_MXC
>  config USB_EHCI_HCD_OMAP
>  	tristate "EHCI support for OMAP3 and later chips"
>  	depends on ARCH_OMAP
> -	select NOP_USB_XCEIV
> +	depends on NOP_USB_XCEIV
>  	default y
>  	---help---
>  	  Enables support for the on-chip EHCI controller on
> diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
> index c6904742e2aa..b9c409a18faa 100644
> --- a/drivers/usb/phy/Kconfig
> +++ b/drivers/usb/phy/Kconfig
> @@ -21,6 +21,7 @@ config AB8500_USB
>  config FSL_USB2_OTG
>  	bool "Freescale USB OTG Transceiver Driver"
>  	depends on USB_EHCI_FSL && USB_FSL_USB2 && USB_OTG_FSM && PM
> +	depends on USB_GADGET || !USB_GADGET # if USB_GADGET=m, this can't be 'y'
>  	select USB_PHY
>  	help
>  	  Enable this to support Freescale USB OTG transceiver.
> @@ -29,6 +30,7 @@ config ISP1301_OMAP
>  	tristate "Philips ISP1301 with OMAP OTG"
>  	depends on I2C && ARCH_OMAP_OTG
>  	depends on USB
> +	depends on USB_GADGET || !USB_GADGET # if USB_GADGET=m, this can't be 'y'
>  	select USB_PHY
>  	help
>  	  If you say yes here you get support for the Philips ISP1301
> @@ -43,7 +45,7 @@ config ISP1301_OMAP
>  config KEYSTONE_USB_PHY
>  	tristate "Keystone USB PHY Driver"
>  	depends on ARCH_KEYSTONE || COMPILE_TEST
> -	select NOP_USB_XCEIV
> +	depends on NOP_USB_XCEIV
>  	help
>  	  Enable this to support Keystone USB phy. This driver provides
>  	  interface to interact with USB 2.0 and USB 3.0 PHY that is part
> @@ -51,6 +53,7 @@ config KEYSTONE_USB_PHY
>  
>  config NOP_USB_XCEIV
>  	tristate "NOP USB Transceiver Driver"
> +	depends on USB_GADGET || !USB_GADGET # if USB_GADGET=m, NOP can't be built-in
>  	select USB_PHY
>  	help
>  	  This driver is to be used by all the usb transceiver which are either
> @@ -63,9 +66,9 @@ config AM335X_CONTROL_USB
>  config AM335X_PHY_USB
>  	tristate "AM335x USB PHY Driver"
>  	depends on ARM || COMPILE_TEST
> +	depends on NOP_USB_XCEIV
>  	select USB_PHY
>  	select AM335X_CONTROL_USB
> -	select NOP_USB_XCEIV
>  	select USB_COMMON
>  	help
>  	  This driver provides PHY support for that phy which part for the
> @@ -92,6 +95,7 @@ config TWL6030_USB
>  config USB_GPIO_VBUS
>  	tristate "GPIO based peripheral-only VBUS sensing 'transceiver'"
>  	depends on GPIOLIB || COMPILE_TEST
> +	depends on USB_GADGET || !USB_GADGET # if USB_GADGET=m, this can't be 'y'
>  	select USB_PHY
>  	help
>  	  Provides simple GPIO VBUS sensing for controllers with an
> @@ -112,6 +116,7 @@ config OMAP_OTG
>  config TAHVO_USB
>  	tristate "Tahvo USB transceiver driver"
>  	depends on MFD_RETU && EXTCON
> +	depends on USB_GADGET || !USB_GADGET # if USB_GADGET=m, this can't be 'y'
>  	select USB_PHY
>  	help
>  	  Enable this to support USB transceiver on Tahvo. This is used
> @@ -140,6 +145,7 @@ config USB_ISP1301
>  config USB_MSM_OTG
>  	tristate "Qualcomm on-chip USB OTG controller support"
>  	depends on (USB || USB_GADGET) && (ARCH_QCOM || COMPILE_TEST)
> +	depends on USB_GADGET || !USB_GADGET # if USB_GADGET=m, this can't be 'y'
>  	depends on RESET_CONTROLLER
>  	depends on EXTCON
>  	select USB_PHY
> @@ -169,6 +175,7 @@ config USB_QCOM_8X16_PHY
>  config USB_MV_OTG
>  	tristate "Marvell USB OTG support"
>  	depends on USB_EHCI_MV && USB_MV_UDC && PM && USB_OTG
> +	depends on USB_GADGET || !USB_GADGET # if USB_GADGET=m, this can't be 'y'
>  	select USB_PHY
>  	help
>  	  Say Y here if you want to build Marvell USB OTG transciever
> diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
> index 457651bf45b0..538ac836354b 100644
> --- a/include/linux/usb/gadget.h
> +++ b/include/linux/usb/gadget.h
> @@ -228,307 +228,49 @@ struct usb_ep {
>  
>  /*-------------------------------------------------------------------------*/
>  
> -/**
> - * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
> - * @ep:the endpoint being configured
> - * @maxpacket_limit:value of maximum packet size limit
> - *
> - * This function should be used only in UDC drivers to initialize endpoint
> - * (usually in probe function).
> - */
> +#if IS_ENABLED(CONFIG_USB_GADGET)
> +void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit);
> +int usb_ep_enable(struct usb_ep *ep);
> +int usb_ep_disable(struct usb_ep *ep);
> +struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags);
> +void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req);
> +int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags);
> +int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req);
> +int usb_ep_set_halt(struct usb_ep *ep);
> +int usb_ep_clear_halt(struct usb_ep *ep);
> +int usb_ep_set_wedge(struct usb_ep *ep);
> +int usb_ep_fifo_status(struct usb_ep *ep);
> +void usb_ep_fifo_flush(struct usb_ep *ep);
> +#else
>  static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
> -					      unsigned maxpacket_limit)
> -{
> -	ep->maxpacket_limit = maxpacket_limit;
> -	ep->maxpacket = maxpacket_limit;
> -}
> -
> -/**
> - * usb_ep_enable - configure endpoint, making it usable
> - * @ep:the endpoint being configured.  may not be the endpoint named "ep0".
> - *	drivers discover endpoints through the ep_list of a usb_gadget.
> - *
> - * When configurations are set, or when interface settings change, the driver
> - * will enable or disable the relevant endpoints.  while it is enabled, an
> - * endpoint may be used for i/o until the driver receives a disconnect() from
> - * the host or until the endpoint is disabled.
> - *
> - * the ep0 implementation (which calls this routine) must ensure that the
> - * hardware capabilities of each endpoint match the descriptor provided
> - * for it.  for example, an endpoint named "ep2in-bulk" would be usable
> - * for interrupt transfers as well as bulk, but it likely couldn't be used
> - * for iso transfers or for endpoint 14.  some endpoints are fully
> - * configurable, with more generic names like "ep-a".  (remember that for
> - * USB, "in" means "towards the USB master".)
> - *
> - * returns zero, or a negative error code.
> - */
> +		unsigned maxpacket_limit)
> +{ }
>  static inline int usb_ep_enable(struct usb_ep *ep)
> -{
> -	int ret;
> -
> -	if (ep->enabled)
> -		return 0;
> -
> -	ret = ep->ops->enable(ep, ep->desc);
> -	if (ret)
> -		return ret;
> -
> -	ep->enabled = true;
> -
> -	return 0;
> -}
> -
> -/**
> - * usb_ep_disable - endpoint is no longer usable
> - * @ep:the endpoint being unconfigured.  may not be the endpoint named "ep0".
> - *
> - * no other task may be using this endpoint when this is called.
> - * any pending and uncompleted requests will complete with status
> - * indicating disconnect (-ESHUTDOWN) before this call returns.
> - * gadget drivers must call usb_ep_enable() again before queueing
> - * requests to the endpoint.
> - *
> - * returns zero, or a negative error code.
> - */
> +{ return 0; }
>  static inline int usb_ep_disable(struct usb_ep *ep)
> -{
> -	int ret;
> -
> -	if (!ep->enabled)
> -		return 0;
> -
> -	ret = ep->ops->disable(ep);
> -	if (ret)
> -		return ret;
> -
> -	ep->enabled = false;
> -
> -	return 0;
> -}
> -
> -/**
> - * usb_ep_alloc_request - allocate a request object to use with this endpoint
> - * @ep:the endpoint to be used with with the request
> - * @gfp_flags:GFP_* flags to use
> - *
> - * Request objects must be allocated with this call, since they normally
> - * need controller-specific setup and may even need endpoint-specific
> - * resources such as allocation of DMA descriptors.
> - * Requests may be submitted with usb_ep_queue(), and receive a single
> - * completion callback.  Free requests with usb_ep_free_request(), when
> - * they are no longer needed.
> - *
> - * Returns the request, or null if one could not be allocated.
> - */
> +{ return 0; }
>  static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
> -						       gfp_t gfp_flags)
> -{
> -	return ep->ops->alloc_request(ep, gfp_flags);
> -}
> -
> -/**
> - * usb_ep_free_request - frees a request object
> - * @ep:the endpoint associated with the request
> - * @req:the request being freed
> - *
> - * Reverses the effect of usb_ep_alloc_request().
> - * Caller guarantees the request is not queued, and that it will
> - * no longer be requeued (or otherwise used).
> - */
> +		gfp_t gfp_flags)
> +{ return NULL; }
>  static inline void usb_ep_free_request(struct usb_ep *ep,
> -				       struct usb_request *req)
> -{
> -	ep->ops->free_request(ep, req);
> -}
> -
> -/**
> - * usb_ep_queue - queues (submits) an I/O request to an endpoint.
> - * @ep:the endpoint associated with the request
> - * @req:the request being submitted
> - * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
> - *	pre-allocate all necessary memory with the request.
> - *
> - * This tells the device controller to perform the specified request through
> - * that endpoint (reading or writing a buffer).  When the request completes,
> - * including being canceled by usb_ep_dequeue(), the request's completion
> - * routine is called to return the request to the driver.  Any endpoint
> - * (except control endpoints like ep0) may have more than one transfer
> - * request queued; they complete in FIFO order.  Once a gadget driver
> - * submits a request, that request may not be examined or modified until it
> - * is given back to that driver through the completion callback.
> - *
> - * Each request is turned into one or more packets.  The controller driver
> - * never merges adjacent requests into the same packet.  OUT transfers
> - * will sometimes use data that's already buffered in the hardware.
> - * Drivers can rely on the fact that the first byte of the request's buffer
> - * always corresponds to the first byte of some USB packet, for both
> - * IN and OUT transfers.
> - *
> - * Bulk endpoints can queue any amount of data; the transfer is packetized
> - * automatically.  The last packet will be short if the request doesn't fill it
> - * out completely.  Zero length packets (ZLPs) should be avoided in portable
> - * protocols since not all usb hardware can successfully handle zero length
> - * packets.  (ZLPs may be explicitly written, and may be implicitly written if
> - * the request 'zero' flag is set.)  Bulk endpoints may also be used
> - * for interrupt transfers; but the reverse is not true, and some endpoints
> - * won't support every interrupt transfer.  (Such as 768 byte packets.)
> - *
> - * Interrupt-only endpoints are less functional than bulk endpoints, for
> - * example by not supporting queueing or not handling buffers that are
> - * larger than the endpoint's maxpacket size.  They may also treat data
> - * toggle differently.
> - *
> - * Control endpoints ... after getting a setup() callback, the driver queues
> - * one response (even if it would be zero length).  That enables the
> - * status ack, after transferring data as specified in the response.  Setup
> - * functions may return negative error codes to generate protocol stalls.
> - * (Note that some USB device controllers disallow protocol stall responses
> - * in some cases.)  When control responses are deferred (the response is
> - * written after the setup callback returns), then usb_ep_set_halt() may be
> - * used on ep0 to trigger protocol stalls.  Depending on the controller,
> - * it may not be possible to trigger a status-stage protocol stall when the
> - * data stage is over, that is, from within the response's completion
> - * routine.
> - *
> - * For periodic endpoints, like interrupt or isochronous ones, the usb host
> - * arranges to poll once per interval, and the gadget driver usually will
> - * have queued some data to transfer at that time.
> - *
> - * Returns zero, or a negative error code.  Endpoints that are not enabled
> - * report errors; errors will also be
> - * reported when the usb peripheral is disconnected.
> - */
> -static inline int usb_ep_queue(struct usb_ep *ep,
> -			       struct usb_request *req, gfp_t gfp_flags)
> -{
> -	if (WARN_ON_ONCE(!ep->enabled && ep->address))
> -		return -ESHUTDOWN;
> -
> -	return ep->ops->queue(ep, req, gfp_flags);
> -}
> -
> -/**
> - * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
> - * @ep:the endpoint associated with the request
> - * @req:the request being canceled
> - *
> - * If the request is still active on the endpoint, it is dequeued and its
> - * completion routine is called (with status -ECONNRESET); else a negative
> - * error code is returned. This is guaranteed to happen before the call to
> - * usb_ep_dequeue() returns.
> - *
> - * Note that some hardware can't clear out write fifos (to unlink the request
> - * at the head of the queue) except as part of disconnecting from usb. Such
> - * restrictions prevent drivers from supporting configuration changes,
> - * even to configuration zero (a "chapter 9" requirement).
> - */
> +		struct usb_request *req)
> +{ }
> +static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req,
> +		gfp_t gfp_flags)
> +{ return 0; }
>  static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
> -{
> -	return ep->ops->dequeue(ep, req);
> -}
> -
> -/**
> - * usb_ep_set_halt - sets the endpoint halt feature.
> - * @ep: the non-isochronous endpoint being stalled
> - *
> - * Use this to stall an endpoint, perhaps as an error report.
> - * Except for control endpoints,
> - * the endpoint stays halted (will not stream any data) until the host
> - * clears this feature; drivers may need to empty the endpoint's request
> - * queue first, to make sure no inappropriate transfers happen.
> - *
> - * Note that while an endpoint CLEAR_FEATURE will be invisible to the
> - * gadget driver, a SET_INTERFACE will not be.  To reset endpoints for the
> - * current altsetting, see usb_ep_clear_halt().  When switching altsettings,
> - * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
> - *
> - * Returns zero, or a negative error code.  On success, this call sets
> - * underlying hardware state that blocks data transfers.
> - * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
> - * transfer requests are still queued, or if the controller hardware
> - * (usually a FIFO) still holds bytes that the host hasn't collected.
> - */
> +{ return 0; }
>  static inline int usb_ep_set_halt(struct usb_ep *ep)
> -{
> -	return ep->ops->set_halt(ep, 1);
> -}
> -
> -/**
> - * usb_ep_clear_halt - clears endpoint halt, and resets toggle
> - * @ep:the bulk or interrupt endpoint being reset
> - *
> - * Use this when responding to the standard usb "set interface" request,
> - * for endpoints that aren't reconfigured, after clearing any other state
> - * in the endpoint's i/o queue.
> - *
> - * Returns zero, or a negative error code.  On success, this call clears
> - * the underlying hardware state reflecting endpoint halt and data toggle.
> - * Note that some hardware can't support this request (like pxa2xx_udc),
> - * and accordingly can't correctly implement interface altsettings.
> - */
> +{ return 0; }
>  static inline int usb_ep_clear_halt(struct usb_ep *ep)
> -{
> -	return ep->ops->set_halt(ep, 0);
> -}
> -
> -/**
> - * usb_ep_set_wedge - sets the halt feature and ignores clear requests
> - * @ep: the endpoint being wedged
> - *
> - * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT)
> - * requests. If the gadget driver clears the halt status, it will
> - * automatically unwedge the endpoint.
> - *
> - * Returns zero on success, else negative errno.
> - */
> -static inline int
> -usb_ep_set_wedge(struct usb_ep *ep)
> -{
> -	if (ep->ops->set_wedge)
> -		return ep->ops->set_wedge(ep);
> -	else
> -		return ep->ops->set_halt(ep, 1);
> -}
> -
> -/**
> - * usb_ep_fifo_status - returns number of bytes in fifo, or error
> - * @ep: the endpoint whose fifo status is being checked.
> - *
> - * FIFO endpoints may have "unclaimed data" in them in certain cases,
> - * such as after aborted transfers.  Hosts may not have collected all
> - * the IN data written by the gadget driver (and reported by a request
> - * completion).  The gadget driver may not have collected all the data
> - * written OUT to it by the host.  Drivers that need precise handling for
> - * fault reporting or recovery may need to use this call.
> - *
> - * This returns the number of such bytes in the fifo, or a negative
> - * errno if the endpoint doesn't use a FIFO or doesn't support such
> - * precise handling.
> - */
> +{ return 0; }
> +static inline int usb_ep_set_wedge(struct usb_ep *ep)
> +{ return 0; }
>  static inline int usb_ep_fifo_status(struct usb_ep *ep)
> -{
> -	if (ep->ops->fifo_status)
> -		return ep->ops->fifo_status(ep);
> -	else
> -		return -EOPNOTSUPP;
> -}
> -
> -/**
> - * usb_ep_fifo_flush - flushes contents of a fifo
> - * @ep: the endpoint whose fifo is being flushed.
> - *
> - * This call may be used to flush the "unclaimed data" that may exist in
> - * an endpoint fifo after abnormal transaction terminations.  The call
> - * must never be used except when endpoint is not being used for any
> - * protocol translation.
> - */
> +{ return 0; }
>  static inline void usb_ep_fifo_flush(struct usb_ep *ep)
> -{
> -	if (ep->ops->fifo_flush)
> -		ep->ops->fifo_flush(ep);
> -}
> -
> +{ }
> +#endif /* USB_GADGET */
>  
>  /*-------------------------------------------------------------------------*/
>  
> @@ -760,251 +502,44 @@ static inline int gadget_is_otg(struct usb_gadget *g)
>  #endif
>  }
>  
> -/**
> - * usb_gadget_frame_number - returns the current frame number
> - * @gadget: controller that reports the frame number
> - *
> - * Returns the usb frame number, normally eleven bits from a SOF packet,
> - * or negative errno if this device doesn't support this capability.
> - */
> -static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
> -{
> -	return gadget->ops->get_frame(gadget);
> -}
> +/*-------------------------------------------------------------------------*/
>  
> -/**
> - * usb_gadget_wakeup - tries to wake up the host connected to this gadget
> - * @gadget: controller used to wake up the host
> - *
> - * Returns zero on success, else negative error code if the hardware
> - * doesn't support such attempts, or its support has not been enabled
> - * by the usb host.  Drivers must return device descriptors that report
> - * their ability to support this, or hosts won't enable it.
> - *
> - * This may also try to use SRP to wake the host and start enumeration,
> - * even if OTG isn't otherwise in use.  OTG devices may also start
> - * remote wakeup even when hosts don't explicitly enable it.
> - */
> +#if IS_ENABLED(CONFIG_USB_GADGET)
> +int usb_gadget_frame_number(struct usb_gadget *gadget);
> +int usb_gadget_wakeup(struct usb_gadget *gadget);
> +int usb_gadget_set_selfpowered(struct usb_gadget *gadget);
> +int usb_gadget_clear_selfpowered(struct usb_gadget *gadget);
> +int usb_gadget_vbus_connect(struct usb_gadget *gadget);
> +int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA);
> +int usb_gadget_vbus_disconnect(struct usb_gadget *gadget);
> +int usb_gadget_connect(struct usb_gadget *gadget);
> +int usb_gadget_disconnect(struct usb_gadget *gadget);
> +int usb_gadget_deactivate(struct usb_gadget *gadget);
> +int usb_gadget_activate(struct usb_gadget *gadget);
> +#else
> +static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
> +{ return 0; }
>  static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
> -{
> -	if (!gadget->ops->wakeup)
> -		return -EOPNOTSUPP;
> -	return gadget->ops->wakeup(gadget);
> -}
> -
> -/**
> - * usb_gadget_set_selfpowered - sets the device selfpowered feature.
> - * @gadget:the device being declared as self-powered
> - *
> - * this affects the device status reported by the hardware driver
> - * to reflect that it now has a local power supply.
> - *
> - * returns zero on success, else negative errno.
> - */
> +{ return 0; }
>  static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
> -{
> -	if (!gadget->ops->set_selfpowered)
> -		return -EOPNOTSUPP;
> -	return gadget->ops->set_selfpowered(gadget, 1);
> -}
> -
> -/**
> - * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
> - * @gadget:the device being declared as bus-powered
> - *
> - * this affects the device status reported by the hardware driver.
> - * some hardware may not support bus-powered operation, in which
> - * case this feature's value can never change.
> - *
> - * returns zero on success, else negative errno.
> - */
> +{ return 0; }
>  static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
> -{
> -	if (!gadget->ops->set_selfpowered)
> -		return -EOPNOTSUPP;
> -	return gadget->ops->set_selfpowered(gadget, 0);
> -}
> -
> -/**
> - * usb_gadget_vbus_connect - Notify controller that VBUS is powered
> - * @gadget:The device which now has VBUS power.
> - * Context: can sleep
> - *
> - * This call is used by a driver for an external transceiver (or GPIO)
> - * that detects a VBUS power session starting.  Common responses include
> - * resuming the controller, activating the D+ (or D-) pullup to let the
> - * host detect that a USB device is attached, and starting to draw power
> - * (8mA or possibly more, especially after SET_CONFIGURATION).
> - *
> - * Returns zero on success, else negative errno.
> - */
> +{ return 0; }
>  static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
> -{
> -	if (!gadget->ops->vbus_session)
> -		return -EOPNOTSUPP;
> -	return gadget->ops->vbus_session(gadget, 1);
> -}
> -
> -/**
> - * usb_gadget_vbus_draw - constrain controller's VBUS power usage
> - * @gadget:The device whose VBUS usage is being described
> - * @mA:How much current to draw, in milliAmperes.  This should be twice
> - *	the value listed in the configuration descriptor bMaxPower field.
> - *
> - * This call is used by gadget drivers during SET_CONFIGURATION calls,
> - * reporting how much power the device may consume.  For example, this
> - * could affect how quickly batteries are recharged.
> - *
> - * Returns zero on success, else negative errno.
> - */
> +{ return 0; }
>  static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
> -{
> -	if (!gadget->ops->vbus_draw)
> -		return -EOPNOTSUPP;
> -	return gadget->ops->vbus_draw(gadget, mA);
> -}
> -
> -/**
> - * usb_gadget_vbus_disconnect - notify controller about VBUS session end
> - * @gadget:the device whose VBUS supply is being described
> - * Context: can sleep
> - *
> - * This call is used by a driver for an external transceiver (or GPIO)
> - * that detects a VBUS power session ending.  Common responses include
> - * reversing everything done in usb_gadget_vbus_connect().
> - *
> - * Returns zero on success, else negative errno.
> - */
> +{ return 0; }
>  static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
> -{
> -	if (!gadget->ops->vbus_session)
> -		return -EOPNOTSUPP;
> -	return gadget->ops->vbus_session(gadget, 0);
> -}
> -
> -/**
> - * usb_gadget_connect - software-controlled connect to USB host
> - * @gadget:the peripheral being connected
> - *
> - * Enables the D+ (or potentially D-) pullup.  The host will start
> - * enumerating this gadget when the pullup is active and a VBUS session
> - * is active (the link is powered).  This pullup is always enabled unless
> - * usb_gadget_disconnect() has been used to disable it.
> - *
> - * Returns zero on success, else negative errno.
> - */
> +{ return 0; }
>  static inline int usb_gadget_connect(struct usb_gadget *gadget)
> -{
> -	int ret;
> -
> -	if (!gadget->ops->pullup)
> -		return -EOPNOTSUPP;
> -
> -	if (gadget->deactivated) {
> -		/*
> -		 * If gadget is deactivated we only save new state.
> -		 * Gadget will be connected automatically after activation.
> -		 */
> -		gadget->connected = true;
> -		return 0;
> -	}
> -
> -	ret = gadget->ops->pullup(gadget, 1);
> -	if (!ret)
> -		gadget->connected = 1;
> -	return ret;
> -}
> -
> -/**
> - * usb_gadget_disconnect - software-controlled disconnect from USB host
> - * @gadget:the peripheral being disconnected
> - *
> - * Disables the D+ (or potentially D-) pullup, which the host may see
> - * as a disconnect (when a VBUS session is active).  Not all systems
> - * support software pullup controls.
> - *
> - * Returns zero on success, else negative errno.
> - */
> +{ return 0; }
>  static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
> -{
> -	int ret;
> -
> -	if (!gadget->ops->pullup)
> -		return -EOPNOTSUPP;
> -
> -	if (gadget->deactivated) {
> -		/*
> -		 * If gadget is deactivated we only save new state.
> -		 * Gadget will stay disconnected after activation.
> -		 */
> -		gadget->connected = false;
> -		return 0;
> -	}
> -
> -	ret = gadget->ops->pullup(gadget, 0);
> -	if (!ret)
> -		gadget->connected = 0;
> -	return ret;
> -}
> -
> -/**
> - * usb_gadget_deactivate - deactivate function which is not ready to work
> - * @gadget: the peripheral being deactivated
> - *
> - * This routine may be used during the gadget driver bind() call to prevent
> - * the peripheral from ever being visible to the USB host, unless later
> - * usb_gadget_activate() is called.  For example, user mode components may
> - * need to be activated before the system can talk to hosts.
> - *
> - * Returns zero on success, else negative errno.
> - */
> +{ return 0; }
>  static inline int usb_gadget_deactivate(struct usb_gadget *gadget)
> -{
> -	int ret;
> -
> -	if (gadget->deactivated)
> -		return 0;
> -
> -	if (gadget->connected) {
> -		ret = usb_gadget_disconnect(gadget);
> -		if (ret)
> -			return ret;
> -		/*
> -		 * If gadget was being connected before deactivation, we want
> -		 * to reconnect it in usb_gadget_activate().
> -		 */
> -		gadget->connected = true;
> -	}
> -	gadget->deactivated = true;
> -
> -	return 0;
> -}
> -
> -/**
> - * usb_gadget_activate - activate function which is not ready to work
> - * @gadget: the peripheral being activated
> - *
> - * This routine activates gadget which was previously deactivated with
> - * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed.
> - *
> - * Returns zero on success, else negative errno.
> - */
> +{ return 0; }
>  static inline int usb_gadget_activate(struct usb_gadget *gadget)
> -{
> -	if (!gadget->deactivated)
> -		return 0;
> -
> -	gadget->deactivated = false;
> -
> -	/*
> -	 * If gadget has been connected before deactivation, or became connected
> -	 * while it was being deactivated, we call usb_gadget_connect().
> -	 */
> -	if (gadget->connected)
> -		return usb_gadget_connect(gadget);
> -
> -	return 0;
> -}
> +{ return 0; }
> +#endif /* CONFIG_USB_GADGET */
>  
>  /*-------------------------------------------------------------------------*/
>  
> -- 
> 2.8.3
> 
> 
> 
> -- 
> balbi



-- 

Best Regards,
Peter Chen
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