auto
     ˆÅÇ„eÖsÄÁÉ ?÷     // SPDX-License-Identifier: GPL-2.0
/*
 * <linux/usb/gadget.h>
 *
 * We call the USB code inside a Linux-based peripheral device a "gadget"
 * driver, except for the hardware-specific bus glue.  One USB host can
 * talk to many USB gadgets, but the gadgets are only able to communicate
 * to one host.
 *
 *
 * (C) Copyright 2002-2004 by David Brownell
 * All Rights Reserved.
 */

#ifndef __LINUX_USB_GADGET_H
#define __LINUX_USB_GADGET_H

#include <linux/configfs.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/scatterlist.h>
#include <linux/types.h>
#include <linux/workqueue.h>
#include <linux/usb/ch9.h>

#define UDC_TRACE_STR_MAX	512

struct usb_ep;

/**
 * struct usb_request - describes one i/o request
 * @buf: Buffer used for data.  Always provide this; some controllers
 *	only use PIO, or don't use DMA for some endpoints.
 * @dma: DMA address corresponding to 'buf'.  If you don't set this
 *	field, and the usb controller needs one, it is responsible
 *	for mapping and unmapping the buffer.
 * @sg: a scatterlist for SG-capable controllers.
 * @num_sgs: number of SG entries
 * @num_mapped_sgs: number of SG entries mapped to DMA (internal)
 * @length: Length of that data
 * @stream_id: The stream id, when USB3.0 bulk streams are being used
 * @is_last: Indicates if this is the last request of a stream_id before
 *	switching to a different stream (required for DWC3 controllers).
 * @no_interrupt: If true, hints that no completion irq is needed.
 *	Helpful sometimes with deep request queues that are handled
 *	directly by DMA controllers.
 * @zero: If true, when writing data, makes the last packet be "short"
 *     by adding a zero length packet as needed;
 * @short_not_ok: When reading data, makes short packets be
 *     treated as errors (queue stops advancing till cleanup).
 * @dma_mapped: Indicates if request has been mapped to DMA (internal)
 * @sg_was_mapped: Set if the scatterlist has been mapped before the request
 * @complete: Function called when request completes, so this request and
 *	its buffer may be re-used.  The function will always be called with
 *	interrupts disabled, and it must not sleep.
 *	Reads terminate with a short packet, or when the buffer fills,
 *	whichever comes first.  When writes terminate, some data bytes
 *	will usually still be in flight (often in a hardware fifo).
 *	Errors (for reads or writes) stop the queue from advancing
 *	until the completion function returns, so that any transfers
 *	invalidated by the error may first be dequeued.
 * @context: For use by the completion callback
 * @list: For use by the gadget driver.
 * @frame_number: Reports the interval number in (micro)frame in which the
 *	isochronous transfer was transmitted or received.
 * @status: Reports completion code, zero or a negative errno.
 *	Normally, faults block the transfer queue from advancing until
 *	the completion callback returns.
 *	Code "-ESHUTDOWN" indicates completion caused by device disconnect,
 *	or when the driver disabled the endpoint.
 * @actual: Reports bytes transferred to/from the buffer.  For reads (OUT
 *	transfers) this may be less than the requested length.  If the
 *	short_not_ok flag is set, short reads are treated as errors
 *	even when status otherwise indicates successful completion.
 *	Note that for writes (IN transfers) some data bytes may still
 *	reside in a device-side FIFO when the request is reported as
 *	complete.
 *
 * These are allocated/freed through the endpoint they're used with.  The
 * hardware's driver can add extra per-request data to the memory it returns,
 * which often avoids separate memory allocations (potential failures),
 * later when the request is queued.
 *
 * Request flags affect request handling, such as whether a zero length
 * packet is written (the "zero" flag), whether a short read should be
 * treated as an error (blocking request queue advance, the "short_not_ok"
 * flag), or hinting that an interrupt is not required (the