linux/drivers/usb/gadget/function/uvc_video.c

// SPDX-License-Identifier: GPL-2.0+
/*
 *	uvc_video.c  --  USB Video Class Gadget driver
 *
 *	Copyright (C) 2009-2010
 *	    Laurent Pinchart ([email protected])
 */

#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/usb/video.h>
#include <linux/unaligned.h>

#include <media/v4l2-dev.h>

#include "uvc.h"
#include "uvc_queue.h"
#include "uvc_video.h"

/* --------------------------------------------------------------------------
 * Video codecs
 */

static int
uvc_video_encode_header(struct uvc_video *video, struct uvc_buffer *buf,
		u8 *data, int len)
{ … }

static int
uvc_video_encode_data(struct uvc_video *video, struct uvc_buffer *buf,
		u8 *data, int len)
{ … }

static void
uvc_video_encode_bulk(struct usb_request *req, struct uvc_video *video,
		struct uvc_buffer *buf)
{ … }

static void
uvc_video_encode_isoc_sg(struct usb_request *req, struct uvc_video *video,
		struct uvc_buffer *buf)
{ … }

static void
uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video,
		struct uvc_buffer *buf)
{ … }

/* --------------------------------------------------------------------------
 * Request handling
 */

/*
 * Callers must take care to hold req_lock when this function may be called
 * from multiple threads. For example, when frames are streaming to the host.
 */
static void
uvc_video_free_request(struct uvc_request *ureq, struct usb_ep *ep)
{ … }

static int uvcg_video_ep_queue(struct uvc_video *video, struct usb_request *req)
{ … }

/* This function must be called with video->req_lock held. */
static int uvcg_video_usb_req_queue(struct uvc_video *video,
	struct usb_request *req, bool queue_to_ep)
{ … }

/*
 * Must only be called from uvcg_video_enable - since after that we only want to
 * queue requests to the endpoint from the uvc_video_complete complete handler.
 * This function is needed in order to 'kick start' the flow of requests from
 * gadget driver to the usb controller.
 */
static void uvc_video_ep_queue_initial_requests(struct uvc_video *video)
{ … }

static void
uvc_video_complete(struct usb_ep *ep, struct usb_request *req)
{ … }

static int
uvc_video_free_requests(struct uvc_video *video)
{ … }

static int
uvc_video_alloc_requests(struct uvc_video *video)
{ … }

/* --------------------------------------------------------------------------
 * Video streaming
 */

/*
 * uvcg_video_pump - Pump video data into the USB requests
 *
 * This function fills the available USB requests (listed in req_free) with
 * video data from the queued buffers.
 */
static void uvcg_video_pump(struct work_struct *work)
{ … }

/*
 * Disable the video stream
 */
int
uvcg_video_disable(struct uvc_video *video)
{ … }

/*
 * Enable the video stream.
 */
int uvcg_video_enable(struct uvc_video *video)
{ … }

/*
 * Initialize the UVC video stream.
 */
int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc)
{ … }