usb: gadget: function: Import uvc from android13-5.10

* Taken as of HEAD 8b3b0f2a448982699cfd8f529e86d474a58c8214
  ("ANDROID: Pixel: Add missing symbol to symbol list")

* Place it in a subfolder, to avoid conflicts when merging upstream

Change-Id: If00e90a06ec5b234c9eb4032d6b6fa5c98fb6055
Signed-off-by: Cyber Knight <cyberknight755@gmail.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>

drivers/usb/gadget/Kconfig

@@ -569,6 +569,7 @@ config USB_CONFIGFS_F_UVC
 	depends on USB_CONFIGFS
 	depends on VIDEO_V4L2
 	depends on VIDEO_DEV
+	select VIDEOBUF2_DMA_SG
 	select VIDEOBUF2_VMALLOC
 	select USB_F_UVC
 	help

drivers/usb/gadget/function/Makefile

@@ -41,8 +41,9 @@ usb_f_uac1_legacy-y		:= f_uac1_legacy.o u_uac1_legacy.o
 obj-$(CONFIG_USB_F_UAC1_LEGACY)	+= usb_f_uac1_legacy.o
 usb_f_uac2-y			:= f_uac2.o
 obj-$(CONFIG_USB_F_UAC2)	+= usb_f_uac2.o
-usb_f_uvc-y			:= f_uvc.o uvc_queue.o uvc_v4l2.o uvc_video.o uvc_configfs.o
-obj-$(CONFIG_USB_F_UVC)		+= usb_f_uvc.o
+#usb_f_uvc-y			:= f_uvc.o uvc_queue.o uvc_v4l2.o uvc_video.o uvc_configfs.o
+#obj-$(CONFIG_USB_F_UVC)		+= usb_f_uvc.o
+obj-$(CONFIG_USB_F_UVC)		+= uvc-new/
 usb_f_midi-y			:= f_midi.o
 obj-$(CONFIG_USB_F_MIDI)	+= usb_f_midi.o
 usb_f_hid-y			:= f_hid.o

drivers/usb/gadget/function/uvc-new/Makefile

@@ -0,0 +1,2 @@
+usb_f_uvc-y			:= f_uvc.o uvc_queue.o uvc_v4l2.o uvc_video.o uvc_configfs.o
+obj-$(CONFIG_USB_F_UVC)		+= usb_f_uvc.o

drivers/usb/gadget/function/uvc-new/f_uvc.h

@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ *	f_uvc.h  --  USB Video Class Gadget driver
+ *
+ *	Copyright (C) 2009-2010
+ *	    Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ */
+
+#ifndef _F_UVC_H_
+#define _F_UVC_H_
+
+struct uvc_device;
+
+void uvc_function_setup_continue(struct uvc_device *uvc, int disable_ep);
+
+void uvc_function_connect(struct uvc_device *uvc);
+
+void uvc_function_disconnect(struct uvc_device *uvc);
+
+#endif /* _F_UVC_H_ */

drivers/usb/gadget/function/uvc-new/u_uvc.h

@@ -0,0 +1,87 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * u_uvc.h
+ *
+ * Utility definitions for the uvc function
+ *
+ * Copyright (c) 2013-2014 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * Author: Andrzej Pietrasiewicz <andrzejtp2010@gmail.com>
+ */
+
+#ifndef U_UVC_H
+#define U_UVC_H
+
+#include <linux/mutex.h>
+#include <linux/usb/composite.h>
+#include <linux/usb/video.h>
+
+#define fi_to_f_uvc_opts(f)	container_of(f, struct f_uvc_opts, func_inst)
+
+struct f_uvc_opts {
+	struct usb_function_instance			func_inst;
+	unsigned int					streaming_interval;
+	unsigned int					streaming_maxpacket;
+	unsigned int					streaming_maxburst;
+
+	unsigned int					control_interface;
+	unsigned int					streaming_interface;
+	char						function_name[32];
+
+	/*
+	 * Control descriptors array pointers for full-/high-speed and
+	 * super-speed. They point by default to the uvc_fs_control_cls and
+	 * uvc_ss_control_cls arrays respectively. Legacy gadgets must
+	 * override them in their gadget bind callback.
+	 */
+	const struct uvc_descriptor_header * const	*fs_control;
+	const struct uvc_descriptor_header * const	*ss_control;
+
+	/*
+	 * Streaming descriptors array pointers for full-speed, high-speed and
+	 * super-speed. They will point to the uvc_[fhs]s_streaming_cls arrays
+	 * for configfs-based gadgets. Legacy gadgets must initialize them in
+	 * their gadget bind callback.
+	 */
+	const struct uvc_descriptor_header * const	*fs_streaming;
+	const struct uvc_descriptor_header * const	*hs_streaming;
+	const struct uvc_descriptor_header * const	*ss_streaming;
+
+	/* Default control descriptors for configfs-based gadgets. */
+	struct uvc_camera_terminal_descriptor		uvc_camera_terminal;
+	struct uvc_processing_unit_descriptor		uvc_processing;
+	struct uvc_output_terminal_descriptor		uvc_output_terminal;
+	struct uvc_color_matching_descriptor		uvc_color_matching;
+
+	/*
+	 * Control descriptors pointers arrays for full-/high-speed and
+	 * super-speed. The first element is a configurable control header
+	 * descriptor, the other elements point to the fixed default control
+	 * descriptors. Used by configfs only, must not be touched by legacy
+	 * gadgets.
+	 */
+	struct uvc_descriptor_header			*uvc_fs_control_cls[5];
+	struct uvc_descriptor_header			*uvc_ss_control_cls[5];
+
+	/*
+	 * Streaming descriptors for full-speed, high-speed and super-speed.
+	 * Used by configfs only, must not be touched by legacy gadgets. The
+	 * arrays are allocated at runtime as the number of descriptors isn't
+	 * known in advance.
+	 */
+	struct uvc_descriptor_header			**uvc_fs_streaming_cls;
+	struct uvc_descriptor_header			**uvc_hs_streaming_cls;
+	struct uvc_descriptor_header			**uvc_ss_streaming_cls;
+
+	/*
+	 * Read/write access to configfs attributes is handled by configfs.
+	 *
+	 * This lock protects the descriptors from concurrent access by
+	 * read/write and symlink creation/removal.
+	 */
+	struct mutex			lock;
+	int				refcnt;
+};
+
+#endif /* U_UVC_H */

drivers/usb/gadget/function/uvc-new/uvc.h

@@ -0,0 +1,192 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ *	uvc_gadget.h  --  USB Video Class Gadget driver
+ *
+ *	Copyright (C) 2009-2010
+ *	    Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ */
+
+#ifndef _UVC_GADGET_H_
+#define _UVC_GADGET_H_
+
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/usb/composite.h>
+#include <linux/videodev2.h>
+#include <linux/wait.h>
+
+#include <media/v4l2-device.h>
+#include <media/v4l2-dev.h>
+#include <media/v4l2-fh.h>
+
+#include "uvc_queue.h"
+
+struct usb_ep;
+struct usb_request;
+struct uvc_descriptor_header;
+struct uvc_device;
+
+/* ------------------------------------------------------------------------
+ * Debugging, printing and logging
+ */
+
+#define UVC_TRACE_PROBE				(1 << 0)
+#define UVC_TRACE_DESCR				(1 << 1)
+#define UVC_TRACE_CONTROL			(1 << 2)
+#define UVC_TRACE_FORMAT			(1 << 3)
+#define UVC_TRACE_CAPTURE			(1 << 4)
+#define UVC_TRACE_CALLS				(1 << 5)
+#define UVC_TRACE_IOCTL				(1 << 6)
+#define UVC_TRACE_FRAME				(1 << 7)
+#define UVC_TRACE_SUSPEND			(1 << 8)
+#define UVC_TRACE_STATUS			(1 << 9)
+
+#define UVC_WARN_MINMAX				0
+#define UVC_WARN_PROBE_DEF			1
+
+extern unsigned int uvc_gadget_trace_param;
+
+#define uvc_trace(flag, msg...) \
+	do { \
+		if (uvc_gadget_trace_param & flag) \
+			printk(KERN_DEBUG "uvcvideo: " msg); \
+	} while (0)
+
+#define uvcg_dbg(f, fmt, args...) \
+	dev_dbg(&(f)->config->cdev->gadget->dev, "%s: " fmt, (f)->name, ##args)
+#define uvcg_info(f, fmt, args...) \
+	dev_info(&(f)->config->cdev->gadget->dev, "%s: " fmt, (f)->name, ##args)
+#define uvcg_warn(f, fmt, args...) \
+	dev_warn(&(f)->config->cdev->gadget->dev, "%s: " fmt, (f)->name, ##args)
+#define uvcg_err(f, fmt, args...) \
+	dev_err(&(f)->config->cdev->gadget->dev, "%s: " fmt, (f)->name, ##args)
+
+/* ------------------------------------------------------------------------
+ * Driver specific constants
+ */
+
+#define UVC_MAX_REQUEST_SIZE			64
+#define UVC_MAX_EVENTS				4
+
+#define UVCG_REQUEST_HEADER_LEN			12
+
+/* ------------------------------------------------------------------------
+ * Structures
+ */
+struct uvc_request {
+	struct usb_request *req;
+	u8 *req_buffer;
+	struct uvc_video *video;
+	struct sg_table sgt;
+	u8 header[UVCG_REQUEST_HEADER_LEN];
+	struct uvc_buffer *last_buf;
+	struct list_head list;
+};
+
+struct uvc_video {
+	struct uvc_device *uvc;
+	struct usb_ep *ep;
+
+	struct work_struct pump;
+	struct workqueue_struct *async_wq;
+
+	/* Frame parameters */
+	u8 bpp;
+	u32 fcc;
+	unsigned int width;
+	unsigned int height;
+	unsigned int imagesize;
+	struct mutex mutex;	/* protects frame parameters */
+
+	unsigned int uvc_num_requests;
+
+	/* Requests */
+	bool is_enabled; /* tracks whether video stream is enabled */
+	unsigned int req_size;
+	struct list_head ureqs; /* all uvc_requests allocated by uvc_video */
+
+	/* USB requests that the video pump thread can encode into */
+	struct list_head req_free;
+
+	/*
+	 * USB requests video pump thread has already encoded into. These are
+	 * ready to be queued to the endpoint.
+	 */
+	struct list_head req_ready;
+	spinlock_t req_lock;
+
+	unsigned int req_int_count;
+
+	void (*encode) (struct usb_request *req, struct uvc_video *video,
+			struct uvc_buffer *buf);
+
+	/* Context data used by the completion handler */
+	__u32 payload_size;
+	__u32 max_payload_size;
+
+	struct uvc_video_queue queue;
+	unsigned int fid;
+};
+
+enum uvc_state {
+	UVC_STATE_DISCONNECTED,
+	UVC_STATE_CONNECTED,
+	UVC_STATE_STREAMING,
+};
+
+struct uvc_device {
+	struct video_device vdev;
+	struct v4l2_device v4l2_dev;
+	enum uvc_state state;
+	struct usb_function func;
+	struct uvc_video video;
+	bool func_connected;
+	wait_queue_head_t func_connected_queue;
+
+	struct uvcg_streaming_header *header;
+
+	/* Descriptors */
+	struct {
+		const struct uvc_descriptor_header * const *fs_control;
+		const struct uvc_descriptor_header * const *ss_control;
+		const struct uvc_descriptor_header * const *fs_streaming;
+		const struct uvc_descriptor_header * const *hs_streaming;
+		const struct uvc_descriptor_header * const *ss_streaming;
+	} desc;
+
+	unsigned int control_intf;
+	struct usb_ep *control_ep;
+	struct usb_request *control_req;
+	void *control_buf;
+
+	unsigned int streaming_intf;
+
+	/* Events */
+	unsigned int event_length;
+	unsigned int event_setup_out : 1;
+};
+
+static inline struct uvc_device *to_uvc(struct usb_function *f)
+{
+	return container_of(f, struct uvc_device, func);
+}
+
+struct uvc_file_handle {
+	struct v4l2_fh vfh;
+	struct uvc_video *device;
+	bool is_uvc_app_handle;
+};
+
+#define to_uvc_file_handle(handle) \
+	container_of(handle, struct uvc_file_handle, vfh)
+
+/* ------------------------------------------------------------------------
+ * Functions
+ */
+
+extern void uvc_function_setup_continue(struct uvc_device *uvc, int disable_ep);
+extern void uvc_function_connect(struct uvc_device *uvc);
+extern void uvc_function_disconnect(struct uvc_device *uvc);
+
+#endif /* _UVC_GADGET_H_ */

drivers/usb/gadget/function/uvc-new/uvc_configfs.h

@@ -0,0 +1,137 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * uvc_configfs.h
+ *
+ * Configfs support for the uvc function.
+ *
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * Author: Andrzej Pietrasiewicz <andrzejtp2010@gmail.com>
+ */
+#ifndef UVC_CONFIGFS_H
+#define UVC_CONFIGFS_H
+
+#include <linux/configfs.h>
+
+#include "u_uvc.h"
+
+static inline struct f_uvc_opts *to_f_uvc_opts(struct config_item *item)
+{
+	return container_of(to_config_group(item), struct f_uvc_opts,
+			    func_inst.group);
+}
+
+#define UVCG_STREAMING_CONTROL_SIZE	1
+
+DECLARE_UVC_HEADER_DESCRIPTOR(1);
+
+struct uvcg_control_header {
+	struct config_item		item;
+	struct UVC_HEADER_DESCRIPTOR(1)	desc;
+	unsigned			linked;
+};
+
+static inline struct uvcg_control_header *to_uvcg_control_header(struct config_item *item)
+{
+	return container_of(item, struct uvcg_control_header, item);
+}
+
+enum uvcg_format_type {
+	UVCG_UNCOMPRESSED = 0,
+	UVCG_MJPEG,
+};
+
+struct uvcg_format {
+	struct config_group	group;
+	enum uvcg_format_type	type;
+	unsigned		linked;
+	struct list_head	frames;
+	unsigned		num_frames;
+	__u8			bmaControls[UVCG_STREAMING_CONTROL_SIZE];
+};
+
+struct uvcg_format_ptr {
+	struct uvcg_format	*fmt;
+	struct list_head	entry;
+};
+
+static inline struct uvcg_format *to_uvcg_format(struct config_item *item)
+{
+	return container_of(to_config_group(item), struct uvcg_format, group);
+}
+
+struct uvcg_streaming_header {
+	struct config_item				item;
+	struct uvc_input_header_descriptor		desc;
+	unsigned					linked;
+	struct list_head				formats;
+	unsigned					num_fmt;
+};
+
+static inline struct uvcg_streaming_header *to_uvcg_streaming_header(struct config_item *item)
+{
+	return container_of(item, struct uvcg_streaming_header, item);
+}
+
+struct uvcg_frame_ptr {
+	struct uvcg_frame	*frm;
+	struct list_head	entry;
+};
+
+struct uvcg_frame {
+	struct config_item	item;
+	enum uvcg_format_type	fmt_type;
+	struct {
+		u8	b_length;
+		u8	b_descriptor_type;
+		u8	b_descriptor_subtype;
+		u8	b_frame_index;
+		u8	bm_capabilities;
+		u16	w_width;
+		u16	w_height;
+		u32	dw_min_bit_rate;
+		u32	dw_max_bit_rate;
+		u32	dw_max_video_frame_buffer_size;
+		u32	dw_default_frame_interval;
+		u8	b_frame_interval_type;
+	} __attribute__((packed)) frame;
+	u32 *dw_frame_interval;
+};
+
+static inline struct uvcg_frame *to_uvcg_frame(struct config_item *item)
+{
+	return container_of(item, struct uvcg_frame, item);
+}
+
+/* -----------------------------------------------------------------------------
+ * streaming/uncompressed/<NAME>
+ */
+
+struct uvcg_uncompressed {
+	struct uvcg_format		fmt;
+	struct uvc_format_uncompressed	desc;
+};
+
+static inline struct uvcg_uncompressed *to_uvcg_uncompressed(struct config_item *item)
+{
+	return container_of(to_uvcg_format(item), struct uvcg_uncompressed, fmt);
+}
+
+/* -----------------------------------------------------------------------------
+ * streaming/mjpeg/<NAME>
+ */
+
+struct uvcg_mjpeg {
+	struct uvcg_format		fmt;
+	struct uvc_format_mjpeg		desc;
+};
+
+static inline struct uvcg_mjpeg *to_uvcg_mjpeg(struct config_item *item)
+{
+	return container_of(to_uvcg_format(item), struct uvcg_mjpeg, fmt);
+}
+
+int uvcg_attach_configfs(struct f_uvc_opts *opts);
+
+#endif /* UVC_CONFIGFS_H */

drivers/usb/gadget/function/uvc-new/uvc_queue.c

@@ -0,0 +1,359 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *	uvc_queue.c  --  USB Video Class driver - Buffers management
+ *
+ *	Copyright (C) 2005-2010
+ *	    Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ */
+
+#include <linux/atomic.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/videodev2.h>
+#include <linux/vmalloc.h>
+#include <linux/wait.h>
+
+#include <media/v4l2-common.h>
+#include <media/videobuf2-dma-sg.h>
+#include <media/videobuf2-vmalloc.h>
+
+#include "uvc.h"
+
+/* ------------------------------------------------------------------------
+ * Video buffers queue management.
+ *
+ * Video queues is initialized by uvcg_queue_init(). The function performs
+ * basic initialization of the uvc_video_queue struct and never fails.
+ *
+ * Video buffers are managed by videobuf2. The driver uses a mutex to protect
+ * the videobuf2 queue operations by serializing calls to videobuf2 and a
+ * spinlock to protect the IRQ queue that holds the buffers to be processed by
+ * the driver.
+ */
+
+/* -----------------------------------------------------------------------------
+ * videobuf2 queue operations
+ */
+
+static int uvc_queue_setup(struct vb2_queue *vq,
+			   unsigned int *nbuffers, unsigned int *nplanes,
+			   unsigned int sizes[], struct device *alloc_devs[])
+{
+	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
+	struct uvc_video *video = container_of(queue, struct uvc_video, queue);
+	unsigned int req_size;
+	unsigned int nreq;
+
+	if (*nbuffers > UVC_MAX_VIDEO_BUFFERS)
+		*nbuffers = UVC_MAX_VIDEO_BUFFERS;
+
+	*nplanes = 1;
+
+	sizes[0] = video->imagesize;
+
+	req_size = video->ep->maxpacket
+		 * max_t(unsigned int, video->ep->maxburst, 1)
+		 * (video->ep->mult);
+
+	/* We divide by two, to increase the chance to run
+	 * into fewer requests for smaller framesizes.
+	 */
+	nreq = DIV_ROUND_UP(DIV_ROUND_UP(sizes[0], 2), req_size);
+	nreq = clamp(nreq, 4U, 64U);
+	video->uvc_num_requests = nreq;
+
+	return 0;
+}
+
+static int uvc_buffer_prepare(struct vb2_buffer *vb)
+{
+	struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
+
+	if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
+	    vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) {
+		uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n");
+		return -EINVAL;
+	}
+
+	if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED))
+		return -ENODEV;
+
+	buf->state = UVC_BUF_STATE_QUEUED;
+	if (queue->use_sg) {
+		buf->sgt = vb2_dma_sg_plane_desc(vb, 0);
+		buf->sg = buf->sgt->sgl;
+	} else {
+		buf->mem = vb2_plane_vaddr(vb, 0);
+	}
+	buf->length = vb2_plane_size(vb, 0);
+	if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		buf->bytesused = 0;
+	else
+		buf->bytesused = vb2_get_plane_payload(vb, 0);
+
+	return 0;
+}
+
+static void uvc_buffer_queue(struct vb2_buffer *vb)
+{
+	struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
+	unsigned long flags;
+
+	spin_lock_irqsave(&queue->irqlock, flags);
+
+	if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) {
+		list_add_tail(&buf->queue, &queue->irqqueue);
+	} else {
+		/*
+		 * If the device is disconnected return the buffer to userspace
+		 * directly. The next QBUF call will fail with -ENODEV.
+		 */
+		buf->state = UVC_BUF_STATE_ERROR;
+		vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
+	}
+
+	spin_unlock_irqrestore(&queue->irqlock, flags);
+}
+
+static const struct vb2_ops uvc_queue_qops = {
+	.queue_setup = uvc_queue_setup,
+	.buf_prepare = uvc_buffer_prepare,
+	.buf_queue = uvc_buffer_queue,
+	.wait_prepare = vb2_ops_wait_prepare,
+	.wait_finish = vb2_ops_wait_finish,
+};
+
+int uvcg_queue_init(struct uvc_video_queue *queue, struct device *dev, enum v4l2_buf_type type,
+		    struct mutex *lock)
+{
+	struct uvc_video *video = container_of(queue, struct uvc_video, queue);
+	struct usb_composite_dev *cdev = video->uvc->func.config->cdev;
+	int ret;
+
+	queue->queue.type = type;
+	queue->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
+	queue->queue.drv_priv = queue;
+	queue->queue.buf_struct_size = sizeof(struct uvc_buffer);
+	queue->queue.ops = &uvc_queue_qops;
+	queue->queue.lock = lock;
+	if (cdev->gadget->sg_supported) {
+		queue->queue.mem_ops = &vb2_dma_sg_memops;
+		queue->use_sg = 1;
+	} else {
+		queue->queue.mem_ops = &vb2_vmalloc_memops;
+	}
+
+	queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY
+				     | V4L2_BUF_FLAG_TSTAMP_SRC_EOF;
+	queue->queue.dev = dev;
+
+	ret = vb2_queue_init(&queue->queue);
+	if (ret)
+		return ret;
+
+	spin_lock_init(&queue->irqlock);
+	INIT_LIST_HEAD(&queue->irqqueue);
+	queue->flags = 0;
+
+	return 0;
+}
+
+/*
+ * Free the video buffers.
+ */
+void uvcg_free_buffers(struct uvc_video_queue *queue)
+{
+	vb2_queue_release(&queue->queue);
+}
+
+/*
+ * Allocate the video buffers.
+ */
+int uvcg_alloc_buffers(struct uvc_video_queue *queue,
+			      struct v4l2_requestbuffers *rb)
+{
+	int ret;
+
+	ret = vb2_reqbufs(&queue->queue, rb);
+
+	return ret ? ret : rb->count;
+}
+
+int uvcg_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
+{
+	return vb2_querybuf(&queue->queue, buf);
+}
+
+int uvcg_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
+{
+	return vb2_qbuf(&queue->queue, NULL, buf);
+}
+
+/*
+ * Dequeue a video buffer. If nonblocking is false, block until a buffer is
+ * available.
+ */
+int uvcg_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,
+			int nonblocking)
+{
+	return vb2_dqbuf(&queue->queue, buf, nonblocking);
+}
+
+/*
+ * Poll the video queue.
+ *
+ * This function implements video queue polling and is intended to be used by
+ * the device poll handler.
+ */
+__poll_t uvcg_queue_poll(struct uvc_video_queue *queue, struct file *file,
+			     poll_table *wait)
+{
+	return vb2_poll(&queue->queue, file, wait);
+}
+
+int uvcg_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
+{
+	return vb2_mmap(&queue->queue, vma);
+}
+
+#ifndef CONFIG_MMU
+/*
+ * Get unmapped area.
+ *
+ * NO-MMU arch need this function to make mmap() work correctly.
+ */
+unsigned long uvcg_queue_get_unmapped_area(struct uvc_video_queue *queue,
+					   unsigned long pgoff)
+{
+	return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
+}
+#endif
+
+/*
+ * Cancel the video buffers queue.
+ *
+ * Cancelling the queue marks all buffers on the irq queue as erroneous,
+ * wakes them up and removes them from the queue.
+ *
+ * If the disconnect parameter is set, further calls to uvc_queue_buffer will
+ * fail with -ENODEV.
+ *
+ * This function acquires the irq spinlock and can be called from interrupt
+ * context.
+ */
+void uvcg_queue_cancel(struct uvc_video_queue *queue, int disconnect)
+{
+	struct uvc_buffer *buf;
+	unsigned long flags;
+
+	spin_lock_irqsave(&queue->irqlock, flags);
+	while (!list_empty(&queue->irqqueue)) {
+		buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
+				       queue);
+		list_del(&buf->queue);
+		buf->state = UVC_BUF_STATE_ERROR;
+		vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_ERROR);
+	}
+	queue->buf_used = 0;
+
+	/*
+	 * This must be protected by the irqlock spinlock to avoid race
+	 * conditions between uvc_queue_buffer and the disconnection event that
+	 * could result in an interruptible wait in uvc_dequeue_buffer. Do not
+	 * blindly replace this logic by checking for the UVC_DEV_DISCONNECTED
+	 * state outside the queue code.
+	 */
+	if (disconnect)
+		queue->flags |= UVC_QUEUE_DISCONNECTED;
+	spin_unlock_irqrestore(&queue->irqlock, flags);
+}
+
+/*
+ * Enable or disable the video buffers queue.
+ *
+ * The queue must be enabled before starting video acquisition and must be
+ * disabled after stopping it. This ensures that the video buffers queue
+ * state can be properly initialized before buffers are accessed from the
+ * interrupt handler.
+ *
+ * Enabling the video queue initializes parameters (such as sequence number,
+ * sync pattern, ...). If the queue is already enabled, return -EBUSY.
+ *
+ * Disabling the video queue cancels the queue and removes all buffers from
+ * the main queue.
+ *
+ * This function can't be called from interrupt context. Use
+ * uvcg_queue_cancel() instead.
+ */
+int uvcg_queue_enable(struct uvc_video_queue *queue, int enable)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	if (enable) {
+		ret = vb2_streamon(&queue->queue, queue->queue.type);
+		if (ret < 0)
+			return ret;
+
+		queue->sequence = 0;
+		queue->buf_used = 0;
+		queue->flags &= ~UVC_QUEUE_DROP_INCOMPLETE;
+	} else {
+		ret = vb2_streamoff(&queue->queue, queue->queue.type);
+		if (ret < 0)
+			return ret;
+
+		spin_lock_irqsave(&queue->irqlock, flags);
+		INIT_LIST_HEAD(&queue->irqqueue);
+
+		/*
+		 * FIXME: We need to clear the DISCONNECTED flag to ensure that
+		 * applications will be able to queue buffers for the next
+		 * streaming run. However, clearing it here doesn't guarantee
+		 * that the device will be reconnected in the meantime.
+		 */
+		queue->flags &= ~UVC_QUEUE_DISCONNECTED;
+		spin_unlock_irqrestore(&queue->irqlock, flags);
+	}
+
+	return ret;
+}
+
+/* called with &queue_irqlock held.. */
+void uvcg_complete_buffer(struct uvc_video_queue *queue,
+					  struct uvc_buffer *buf)
+{
+	if (queue->flags & UVC_QUEUE_DROP_INCOMPLETE) {
+		queue->flags &= ~UVC_QUEUE_DROP_INCOMPLETE;
+		buf->state = UVC_BUF_STATE_ERROR;
+		vb2_set_plane_payload(&buf->buf.vb2_buf, 0, 0);
+		vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_ERROR);
+		return;
+	}
+
+	buf->buf.field = V4L2_FIELD_NONE;
+	buf->buf.sequence = queue->sequence++;
+	buf->buf.vb2_buf.timestamp = ktime_get_ns();
+
+	vb2_set_plane_payload(&buf->buf.vb2_buf, 0, buf->bytesused);
+	vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE);
+}
+
+struct uvc_buffer *uvcg_queue_head(struct uvc_video_queue *queue)
+{
+	struct uvc_buffer *buf = NULL;
+
+	if (!list_empty(&queue->irqqueue))
+		buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
+				       queue);
+
+	return buf;
+}
+

drivers/usb/gadget/function/uvc-new/uvc_queue.h

@@ -0,0 +1,101 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _UVC_QUEUE_H_
+#define _UVC_QUEUE_H_
+
+#include <linux/list.h>
+#include <linux/poll.h>
+#include <linux/spinlock.h>
+
+#include <media/videobuf2-v4l2.h>
+
+struct file;
+struct mutex;
+
+/* Maximum frame size in bytes, for sanity checking. */
+#define UVC_MAX_FRAME_SIZE	(16*1024*1024)
+/* Maximum number of video buffers. */
+#define UVC_MAX_VIDEO_BUFFERS	32
+
+/* ------------------------------------------------------------------------
+ * Structures.
+ */
+
+enum uvc_buffer_state {
+	UVC_BUF_STATE_IDLE	= 0,
+	UVC_BUF_STATE_QUEUED	= 1,
+	UVC_BUF_STATE_ACTIVE	= 2,
+	UVC_BUF_STATE_DONE	= 3,
+	UVC_BUF_STATE_ERROR	= 4,
+};
+
+struct uvc_buffer {
+	struct vb2_v4l2_buffer buf;
+	struct list_head queue;
+
+	enum uvc_buffer_state state;
+	void *mem;
+	struct sg_table *sgt;
+	struct scatterlist *sg;
+	unsigned int offset;
+	unsigned int length;
+	unsigned int bytesused;
+};
+
+#define UVC_QUEUE_DISCONNECTED		(1 << 0)
+#define UVC_QUEUE_DROP_INCOMPLETE	(1 << 1)
+
+struct uvc_video_queue {
+	struct vb2_queue queue;
+
+	unsigned int flags;
+	__u32 sequence;
+
+	unsigned int buf_used;
+
+	bool use_sg;
+
+	spinlock_t irqlock;	/* Protects flags and irqqueue */
+	struct list_head irqqueue;
+};
+
+static inline int uvc_queue_streaming(struct uvc_video_queue *queue)
+{
+	return vb2_is_streaming(&queue->queue);
+}
+
+int uvcg_queue_init(struct uvc_video_queue *queue, struct device *dev, enum v4l2_buf_type type,
+		    struct mutex *lock);
+
+void uvcg_free_buffers(struct uvc_video_queue *queue);
+
+int uvcg_alloc_buffers(struct uvc_video_queue *queue,
+		       struct v4l2_requestbuffers *rb);
+
+int uvcg_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf);
+
+int uvcg_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf);
+
+int uvcg_dequeue_buffer(struct uvc_video_queue *queue,
+			struct v4l2_buffer *buf, int nonblocking);
+
+__poll_t uvcg_queue_poll(struct uvc_video_queue *queue,
+			     struct file *file, poll_table *wait);
+
+int uvcg_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma);
+
+#ifndef CONFIG_MMU
+unsigned long uvcg_queue_get_unmapped_area(struct uvc_video_queue *queue,
+					   unsigned long pgoff);
+#endif /* CONFIG_MMU */
+
+void uvcg_queue_cancel(struct uvc_video_queue *queue, int disconnect);
+
+int uvcg_queue_enable(struct uvc_video_queue *queue, int enable);
+
+void uvcg_complete_buffer(struct uvc_video_queue *queue,
+					  struct uvc_buffer *buf);
+
+struct uvc_buffer *uvcg_queue_head(struct uvc_video_queue *queue);
+
+#endif /* _UVC_QUEUE_H_ */
+

drivers/usb/gadget/function/uvc-new/uvc_v4l2.c

@@ -0,0 +1,662 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *	uvc_v4l2.c  --  USB Video Class Gadget driver
+ *
+ *	Copyright (C) 2009-2010
+ *	    Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ */
+
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/usb/g_uvc-new.h>
+#include <linux/videodev2.h>
+#include <linux/vmalloc.h>
+#include <linux/wait.h>
+
+#include <media/v4l2-dev.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-uvc.h>
+
+#include "f_uvc.h"
+#include "uvc.h"
+#include "uvc_queue.h"
+#include "uvc_video.h"
+#include "uvc_v4l2.h"
+#include "uvc_configfs.h"
+
+static struct uvc_format_desc *to_uvc_format(struct uvcg_format *uformat)
+{
+	char guid[16] = UVC_GUID_FORMAT_MJPEG;
+	struct uvc_format_desc *format;
+	struct uvcg_uncompressed *unc;
+
+	if (uformat->type == UVCG_UNCOMPRESSED) {
+		unc = to_uvcg_uncompressed(&uformat->group.cg_item);
+		if (!unc)
+			return ERR_PTR(-EINVAL);
+
+		memcpy(guid, unc->desc.guidFormat, sizeof(guid));
+	}
+
+	format = uvc_format_by_guid(guid);
+	if (!format)
+		return ERR_PTR(-EINVAL);
+
+	return format;
+}
+
+static int uvc_v4l2_get_bytesperline(struct uvcg_format *uformat,
+			      struct uvcg_frame *uframe)
+{
+	struct uvcg_uncompressed *u;
+
+	if (uformat->type == UVCG_UNCOMPRESSED) {
+		u = to_uvcg_uncompressed(&uformat->group.cg_item);
+		if (!u)
+			return 0;
+
+		return u->desc.bBitsPerPixel * uframe->frame.w_width / 8;
+	}
+
+	return 0;
+}
+
+static int uvc_get_frame_size(struct uvcg_format *uformat,
+		       struct uvcg_frame *uframe)
+{
+	unsigned int bpl = uvc_v4l2_get_bytesperline(uformat, uframe);
+
+	return bpl ? bpl * uframe->frame.w_height :
+		uframe->frame.dw_max_video_frame_buffer_size;
+}
+
+static struct uvcg_format *find_format_by_index(struct uvc_device *uvc, int index)
+{
+	struct uvcg_format_ptr *format;
+	struct uvcg_format *uformat = NULL;
+	int i = 1;
+
+	list_for_each_entry(format, &uvc->header->formats, entry) {
+		if (index == i) {
+			uformat = format->fmt;
+			break;
+		}
+		i++;
+	}
+
+	return uformat;
+}
+
+static struct uvcg_frame *find_frame_by_index(struct uvc_device *uvc,
+				       struct uvcg_format *uformat,
+				       int index)
+{
+	struct uvcg_format_ptr *format;
+	struct uvcg_frame_ptr *frame;
+	struct uvcg_frame *uframe = NULL;
+
+	list_for_each_entry(format, &uvc->header->formats, entry) {
+		if (format->fmt->type != uformat->type)
+			continue;
+		list_for_each_entry(frame, &format->fmt->frames, entry) {
+			if (index == frame->frm->frame.b_frame_index) {
+				uframe = frame->frm;
+				break;
+			}
+		}
+	}
+
+	return uframe;
+}
+
+static struct uvcg_format *find_format_by_pix(struct uvc_device *uvc,
+					      u32 pixelformat)
+{
+	struct uvcg_format_ptr *format;
+	struct uvcg_format *uformat = NULL;
+
+	list_for_each_entry(format, &uvc->header->formats, entry) {
+		struct uvc_format_desc *fmtdesc = to_uvc_format(format->fmt);
+
+		if (fmtdesc->fcc == pixelformat) {
+			uformat = format->fmt;
+			break;
+		}
+	}
+
+	return uformat;
+}
+
+static struct uvcg_frame *find_closest_frame_by_size(struct uvc_device *uvc,
+					   struct uvcg_format *uformat,
+					   u16 rw, u16 rh)
+{
+	struct uvc_video *video = &uvc->video;
+	struct uvcg_format_ptr *format;
+	struct uvcg_frame_ptr *frame;
+	struct uvcg_frame *uframe = NULL;
+	unsigned int d, maxd;
+
+	/* Find the closest image size. The distance between image sizes is
+	 * the size in pixels of the non-overlapping regions between the
+	 * requested size and the frame-specified size.
+	 */
+	maxd = (unsigned int)-1;
+
+	list_for_each_entry(format, &uvc->header->formats, entry) {
+		if (format->fmt->type != uformat->type)
+			continue;
+
+		list_for_each_entry(frame, &format->fmt->frames, entry) {
+			u16 w, h;
+
+			w = frame->frm->frame.w_width;
+			h = frame->frm->frame.w_height;
+
+			d = min(w, rw) * min(h, rh);
+			d = w*h + rw*rh - 2*d;
+			if (d < maxd) {
+				maxd = d;
+				uframe = frame->frm;
+			}
+
+			if (maxd == 0)
+				break;
+		}
+	}
+
+	if (!uframe)
+		uvcg_dbg(&video->uvc->func, "Unsupported size %ux%u\n", rw, rh);
+
+	return uframe;
+}
+
+/* --------------------------------------------------------------------------
+ * Requests handling
+ */
+
+static int
+uvc_send_response(struct uvc_device *uvc, struct uvc_request_data *data)
+{
+	struct usb_composite_dev *cdev = uvc->func.config->cdev;
+	struct usb_request *req = uvc->control_req;
+
+	if (data->length < 0)
+		return usb_ep_set_halt(cdev->gadget->ep0);
+
+	req->length = min_t(unsigned int, uvc->event_length, data->length);
+	req->zero = data->length < uvc->event_length;
+
+	memcpy(req->buf, data->data, req->length);
+
+	return usb_ep_queue(cdev->gadget->ep0, req, GFP_KERNEL);
+}
+
+/* --------------------------------------------------------------------------
+ * V4L2 ioctls
+ */
+
+static int
+uvc_v4l2_querycap(struct file *file, void *fh, struct v4l2_capability *cap)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+	struct usb_composite_dev *cdev = uvc->func.config->cdev;
+
+	strscpy(cap->driver, "g_uvc", sizeof(cap->driver));
+	strscpy(cap->card, cdev->gadget->name, sizeof(cap->card));
+	strscpy(cap->bus_info, dev_name(&cdev->gadget->dev),
+		sizeof(cap->bus_info));
+	return 0;
+}
+
+static int
+uvc_v4l2_get_format(struct file *file, void *fh, struct v4l2_format *fmt)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+	struct uvc_video *video = &uvc->video;
+
+	fmt->fmt.pix.pixelformat = video->fcc;
+	fmt->fmt.pix.width = video->width;
+	fmt->fmt.pix.height = video->height;
+	fmt->fmt.pix.field = V4L2_FIELD_NONE;
+	fmt->fmt.pix.bytesperline = video->bpp * video->width / 8;
+	fmt->fmt.pix.sizeimage = video->imagesize;
+	fmt->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB;
+	fmt->fmt.pix.priv = 0;
+
+	return 0;
+}
+
+static int
+uvc_v4l2_try_format(struct file *file, void *fh, struct v4l2_format *fmt)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+	struct uvc_video *video = &uvc->video;
+	struct uvcg_format *uformat;
+	struct uvcg_frame *uframe;
+	u8 *fcc;
+
+	if (fmt->type != video->queue.queue.type)
+		return -EINVAL;
+
+	fcc = (u8 *)&fmt->fmt.pix.pixelformat;
+	uvcg_dbg(&uvc->func, "Trying format 0x%08x (%c%c%c%c): %ux%u\n",
+		fmt->fmt.pix.pixelformat,
+		fcc[0], fcc[1], fcc[2], fcc[3],
+		fmt->fmt.pix.width, fmt->fmt.pix.height);
+
+	uformat = find_format_by_pix(uvc, fmt->fmt.pix.pixelformat);
+	if (!uformat)
+		return -EINVAL;
+
+	uframe = find_closest_frame_by_size(uvc, uformat,
+				fmt->fmt.pix.width, fmt->fmt.pix.height);
+	if (!uframe)
+		return -EINVAL;
+
+	fmt->fmt.pix.width = uframe->frame.w_width;
+	fmt->fmt.pix.height = uframe->frame.w_height;
+	fmt->fmt.pix.field = V4L2_FIELD_NONE;
+	fmt->fmt.pix.bytesperline = uvc_v4l2_get_bytesperline(uformat, uframe);
+	fmt->fmt.pix.sizeimage = uvc_get_frame_size(uformat, uframe);
+	fmt->fmt.pix.pixelformat = to_uvc_format(uformat)->fcc;
+	fmt->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB;
+	fmt->fmt.pix.priv = 0;
+
+	return 0;
+}
+
+static int
+uvc_v4l2_set_format(struct file *file, void *fh, struct v4l2_format *fmt)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+	struct uvc_video *video = &uvc->video;
+	int ret;
+
+	ret = uvc_v4l2_try_format(file, fh, fmt);
+	if (ret)
+		return ret;
+
+	video->fcc = fmt->fmt.pix.pixelformat;
+	video->bpp = fmt->fmt.pix.bytesperline * 8 / video->width;
+	video->width = fmt->fmt.pix.width;
+	video->height = fmt->fmt.pix.height;
+	video->imagesize = fmt->fmt.pix.sizeimage;
+
+	return ret;
+}
+
+static int
+uvc_v4l2_enum_frameintervals(struct file *file, void *fh,
+		struct v4l2_frmivalenum *fival)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+	struct uvcg_format *uformat = NULL;
+	struct uvcg_frame *uframe = NULL;
+	struct uvcg_frame_ptr *frame;
+
+	uformat = find_format_by_pix(uvc, fival->pixel_format);
+	if (!uformat)
+		return -EINVAL;
+
+	list_for_each_entry(frame, &uformat->frames, entry) {
+		if (frame->frm->frame.w_width == fival->width &&
+		    frame->frm->frame.w_height == fival->height) {
+			uframe = frame->frm;
+			break;
+		}
+	}
+	if (!uframe)
+		return -EINVAL;
+
+	if (fival->index >= uframe->frame.b_frame_interval_type)
+		return -EINVAL;
+
+	fival->discrete.numerator =
+		uframe->dw_frame_interval[fival->index];
+
+	/* TODO: handle V4L2_FRMIVAL_TYPE_STEPWISE */
+	fival->type = V4L2_FRMIVAL_TYPE_DISCRETE;
+	fival->discrete.denominator = 10000000;
+	v4l2_simplify_fraction(&fival->discrete.numerator,
+		&fival->discrete.denominator, 8, 333);
+
+	return 0;
+}
+
+static int
+uvc_v4l2_enum_framesizes(struct file *file, void *fh,
+		struct v4l2_frmsizeenum *fsize)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+	struct uvcg_format *uformat = NULL;
+	struct uvcg_frame *uframe = NULL;
+
+	uformat = find_format_by_pix(uvc, fsize->pixel_format);
+	if (!uformat)
+		return -EINVAL;
+
+	if (fsize->index >= uformat->num_frames)
+		return -EINVAL;
+
+	uframe = find_frame_by_index(uvc, uformat, fsize->index + 1);
+	if (!uframe)
+		return -EINVAL;
+
+	fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
+	fsize->discrete.width = uframe->frame.w_width;
+	fsize->discrete.height = uframe->frame.w_height;
+
+	return 0;
+}
+
+static int
+uvc_v4l2_enum_format(struct file *file, void *fh, struct v4l2_fmtdesc *f)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+	struct uvc_format_desc *fmtdesc;
+	struct uvcg_format *uformat;
+
+	if (f->index >= uvc->header->num_fmt)
+		return -EINVAL;
+
+	uformat = find_format_by_index(uvc, f->index + 1);
+	if (!uformat)
+		return -EINVAL;
+
+	if (uformat->type != UVCG_UNCOMPRESSED)
+		f->flags |= V4L2_FMT_FLAG_COMPRESSED;
+
+	fmtdesc = to_uvc_format(uformat);
+	f->pixelformat = fmtdesc->fcc;
+
+	strscpy(f->description, fmtdesc->name, sizeof(f->description));
+	f->description[strlen(fmtdesc->name) - 1] = 0;
+
+	return 0;
+}
+
+static int
+uvc_v4l2_reqbufs(struct file *file, void *fh, struct v4l2_requestbuffers *b)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+	struct uvc_video *video = &uvc->video;
+
+	if (b->type != video->queue.queue.type)
+		return -EINVAL;
+
+	return uvcg_alloc_buffers(&video->queue, b);
+}
+
+static int
+uvc_v4l2_querybuf(struct file *file, void *fh, struct v4l2_buffer *b)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+	struct uvc_video *video = &uvc->video;
+
+	return uvcg_query_buffer(&video->queue, b);
+}
+
+static int
+uvc_v4l2_qbuf(struct file *file, void *fh, struct v4l2_buffer *b)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+	struct uvc_video *video = &uvc->video;
+	int ret;
+
+	ret = uvcg_queue_buffer(&video->queue, b);
+	if (ret < 0)
+		return ret;
+
+	if (uvc->state == UVC_STATE_STREAMING)
+		queue_work(video->async_wq, &video->pump);
+
+	return ret;
+}
+
+static int
+uvc_v4l2_dqbuf(struct file *file, void *fh, struct v4l2_buffer *b)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+	struct uvc_video *video = &uvc->video;
+
+	return uvcg_dequeue_buffer(&video->queue, b, file->f_flags & O_NONBLOCK);
+}
+
+static int
+uvc_v4l2_streamon(struct file *file, void *fh, enum v4l2_buf_type type)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+	struct uvc_video *video = &uvc->video;
+	int ret;
+
+	if (type != video->queue.queue.type)
+		return -EINVAL;
+
+	/* Enable UVC video. */
+	ret = uvcg_video_enable(video);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * Complete the alternate setting selection setup phase now that
+	 * userspace is ready to provide video frames.
+	 */
+	uvc_function_setup_continue(uvc, 0);
+	uvc->state = UVC_STATE_STREAMING;
+
+	return 0;
+}
+
+static int
+uvc_v4l2_streamoff(struct file *file, void *fh, enum v4l2_buf_type type)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+	struct uvc_video *video = &uvc->video;
+	int ret = 0;
+
+	if (type != video->queue.queue.type)
+		return -EINVAL;
+
+	ret = uvcg_video_disable(video);
+	if (ret < 0)
+		return ret;
+
+	uvc->state = UVC_STATE_CONNECTED;
+	uvc_function_setup_continue(uvc, 1);
+	return 0;
+}
+
+static int
+uvc_v4l2_subscribe_event(struct v4l2_fh *fh,
+			 const struct v4l2_event_subscription *sub)
+{
+	struct uvc_device *uvc = video_get_drvdata(fh->vdev);
+	struct uvc_file_handle *handle = to_uvc_file_handle(fh);
+	int ret;
+
+	if (sub->type < UVC_EVENT_FIRST || sub->type > UVC_EVENT_LAST)
+		return -EINVAL;
+
+	if (sub->type == UVC_EVENT_SETUP && uvc->func_connected)
+		return -EBUSY;
+
+	ret = v4l2_event_subscribe(fh, sub, 2, NULL);
+	if (ret < 0)
+		return ret;
+
+	if (sub->type == UVC_EVENT_SETUP) {
+		uvc->func_connected = true;
+		handle->is_uvc_app_handle = true;
+		uvc_function_connect(uvc);
+	}
+
+	return 0;
+}
+
+static void uvc_v4l2_disable(struct uvc_device *uvc)
+{
+	uvc_function_disconnect(uvc);
+	uvcg_video_disable(&uvc->video);
+	uvcg_free_buffers(&uvc->video.queue);
+	uvc->func_connected = false;
+	wake_up_interruptible(&uvc->func_connected_queue);
+}
+
+static int
+uvc_v4l2_unsubscribe_event(struct v4l2_fh *fh,
+			   const struct v4l2_event_subscription *sub)
+{
+	struct uvc_device *uvc = video_get_drvdata(fh->vdev);
+	struct uvc_file_handle *handle = to_uvc_file_handle(fh);
+	int ret;
+
+	ret = v4l2_event_unsubscribe(fh, sub);
+	if (ret < 0)
+		return ret;
+
+	if (sub->type == UVC_EVENT_SETUP && handle->is_uvc_app_handle) {
+		uvc_v4l2_disable(uvc);
+		handle->is_uvc_app_handle = false;
+	}
+
+	return 0;
+}
+
+static long
+uvc_v4l2_ioctl_default(struct file *file, void *fh, bool valid_prio,
+		       unsigned int cmd, void *arg)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+
+	switch (cmd) {
+	case UVCIOC_SEND_RESPONSE:
+		return uvc_send_response(uvc, arg);
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
+const struct v4l2_ioctl_ops uvc_v4l2_ioctl_ops = {
+	.vidioc_querycap = uvc_v4l2_querycap,
+	.vidioc_try_fmt_vid_out = uvc_v4l2_try_format,
+	.vidioc_g_fmt_vid_out = uvc_v4l2_get_format,
+	.vidioc_s_fmt_vid_out = uvc_v4l2_set_format,
+	.vidioc_enum_frameintervals = uvc_v4l2_enum_frameintervals,
+	.vidioc_enum_framesizes = uvc_v4l2_enum_framesizes,
+	.vidioc_enum_fmt_vid_out = uvc_v4l2_enum_format,
+	.vidioc_reqbufs = uvc_v4l2_reqbufs,
+	.vidioc_querybuf = uvc_v4l2_querybuf,
+	.vidioc_qbuf = uvc_v4l2_qbuf,
+	.vidioc_dqbuf = uvc_v4l2_dqbuf,
+	.vidioc_streamon = uvc_v4l2_streamon,
+	.vidioc_streamoff = uvc_v4l2_streamoff,
+	.vidioc_subscribe_event = uvc_v4l2_subscribe_event,
+	.vidioc_unsubscribe_event = uvc_v4l2_unsubscribe_event,
+	.vidioc_default = uvc_v4l2_ioctl_default,
+};
+
+/* --------------------------------------------------------------------------
+ * V4L2
+ */
+
+static int
+uvc_v4l2_open(struct file *file)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+	struct uvc_file_handle *handle;
+
+	handle = kzalloc(sizeof(*handle), GFP_KERNEL);
+	if (handle == NULL)
+		return -ENOMEM;
+
+	v4l2_fh_init(&handle->vfh, vdev);
+	v4l2_fh_add(&handle->vfh);
+
+	handle->device = &uvc->video;
+	file->private_data = &handle->vfh;
+
+	return 0;
+}
+
+static int
+uvc_v4l2_release(struct file *file)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+	struct uvc_file_handle *handle = to_uvc_file_handle(file->private_data);
+	struct uvc_video *video = handle->device;
+
+	mutex_lock(&video->mutex);
+	if (handle->is_uvc_app_handle)
+		uvc_v4l2_disable(uvc);
+	mutex_unlock(&video->mutex);
+
+	file->private_data = NULL;
+	v4l2_fh_del(&handle->vfh);
+	v4l2_fh_exit(&handle->vfh);
+	kfree(handle);
+
+	return 0;
+}
+
+static int
+uvc_v4l2_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+
+	return uvcg_queue_mmap(&uvc->video.queue, vma);
+}
+
+static __poll_t
+uvc_v4l2_poll(struct file *file, poll_table *wait)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+
+	return uvcg_queue_poll(&uvc->video.queue, file, wait);
+}
+
+#ifndef CONFIG_MMU
+static unsigned long uvcg_v4l2_get_unmapped_area(struct file *file,
+		unsigned long addr, unsigned long len, unsigned long pgoff,
+		unsigned long flags)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+
+	return uvcg_queue_get_unmapped_area(&uvc->video.queue, pgoff);
+}
+#endif
+
+const struct v4l2_file_operations uvc_v4l2_fops = {
+	.owner		= THIS_MODULE,
+	.open		= uvc_v4l2_open,
+	.release	= uvc_v4l2_release,
+	.unlocked_ioctl	= video_ioctl2,
+	.mmap		= uvc_v4l2_mmap,
+	.poll		= uvc_v4l2_poll,
+#ifndef CONFIG_MMU
+	.get_unmapped_area = uvcg_v4l2_get_unmapped_area,
+#endif
+};

drivers/usb/gadget/function/uvc-new/uvc_v4l2.h

@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *	uvc_v4l2.h  --  USB Video Class Gadget driver
+ *
+ * Copyright (C) 2009-2010
+ *		Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ *
+ * Copyright (c) 2013 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *		Author: Andrzej Pietrasiewicz <andrzejtp2010@gmail.com>
+ */
+
+#ifndef __UVC_V4L2_H__
+#define __UVC_V4L2_H__
+
+extern const struct v4l2_ioctl_ops uvc_v4l2_ioctl_ops;
+extern const struct v4l2_file_operations uvc_v4l2_fops;
+
+#endif /* __UVC_V4L2_H__ */

drivers/usb/gadget/function/uvc-new/uvc_video.c

@@ -0,0 +1,791 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *	uvc_video.c  --  USB Video Class Gadget driver
+ *
+ *	Copyright (C) 2009-2010
+ *	    Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ */
+
+#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 <asm/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)
+{
+	struct uvc_device *uvc = container_of(video, struct uvc_device, video);
+	struct usb_composite_dev *cdev = uvc->func.config->cdev;
+	struct timespec64 ts = ns_to_timespec64(buf->buf.vb2_buf.timestamp);
+	int pos = 2;
+
+	data[1] = UVC_STREAM_EOH | video->fid;
+
+	if (video->queue.buf_used == 0 && ts.tv_sec) {
+		/* dwClockFrequency is 48 MHz */
+		u32 pts = ((u64)ts.tv_sec * USEC_PER_SEC + ts.tv_nsec / NSEC_PER_USEC) * 48;
+
+		data[1] |= UVC_STREAM_PTS;
+		put_unaligned_le32(pts, &data[pos]);
+		pos += 4;
+	}
+
+	if (cdev->gadget->ops->get_frame) {
+		u32 sof, stc;
+
+		sof = usb_gadget_frame_number(cdev->gadget);
+		ktime_get_ts64(&ts);
+		stc = ((u64)ts.tv_sec * USEC_PER_SEC + ts.tv_nsec / NSEC_PER_USEC) * 48;
+
+		data[1] |= UVC_STREAM_SCR;
+		put_unaligned_le32(stc, &data[pos]);
+		put_unaligned_le16(sof, &data[pos+4]);
+		pos += 6;
+	}
+
+	data[0] = pos;
+
+	if (buf->bytesused - video->queue.buf_used <= len - pos)
+		data[1] |= UVC_STREAM_EOF;
+
+	return pos;
+}
+
+static int
+uvc_video_encode_data(struct uvc_video *video, struct uvc_buffer *buf,
+		u8 *data, int len)
+{
+	struct uvc_video_queue *queue = &video->queue;
+	unsigned int nbytes;
+	void *mem;
+
+	/* Copy video data to the USB buffer. */
+	mem = buf->mem + queue->buf_used;
+	nbytes = min((unsigned int)len, buf->bytesused - queue->buf_used);
+
+	memcpy(data, mem, nbytes);
+	queue->buf_used += nbytes;
+
+	return nbytes;
+}
+
+static void
+uvc_video_encode_bulk(struct usb_request *req, struct uvc_video *video,
+		struct uvc_buffer *buf)
+{
+	void *mem = req->buf;
+	struct uvc_request *ureq = req->context;
+	int len = video->req_size;
+	int ret;
+
+	/* Add a header at the beginning of the payload. */
+	if (video->payload_size == 0) {
+		ret = uvc_video_encode_header(video, buf, mem, len);
+		video->payload_size += ret;
+		mem += ret;
+		len -= ret;
+	}
+
+	/* Process video data. */
+	len = min((int)(video->max_payload_size - video->payload_size), len);
+	ret = uvc_video_encode_data(video, buf, mem, len);
+
+	video->payload_size += ret;
+	len -= ret;
+
+	req->length = video->req_size - len;
+	req->zero = video->payload_size == video->max_payload_size;
+
+	if (buf->bytesused == video->queue.buf_used) {
+		video->queue.buf_used = 0;
+		buf->state = UVC_BUF_STATE_DONE;
+		list_del(&buf->queue);
+		video->fid ^= UVC_STREAM_FID;
+		ureq->last_buf = buf;
+
+		video->payload_size = 0;
+	}
+
+	if (video->payload_size == video->max_payload_size ||
+	    video->queue.flags & UVC_QUEUE_DROP_INCOMPLETE ||
+	    buf->bytesused == video->queue.buf_used)
+		video->payload_size = 0;
+}
+
+static void
+uvc_video_encode_isoc_sg(struct usb_request *req, struct uvc_video *video,
+		struct uvc_buffer *buf)
+{
+	unsigned int pending = buf->bytesused - video->queue.buf_used;
+	struct uvc_request *ureq = req->context;
+	struct scatterlist *sg, *iter;
+	unsigned int len = video->req_size;
+	unsigned int sg_left, part = 0;
+	unsigned int i;
+	int header_len;
+
+	sg = ureq->sgt.sgl;
+	sg_init_table(sg, ureq->sgt.nents);
+
+	/* Init the header. */
+	header_len = uvc_video_encode_header(video, buf, ureq->header,
+				      video->req_size);
+	sg_set_buf(sg, ureq->header, header_len);
+	len -= header_len;
+
+	if (pending <= len)
+		len = pending;
+
+	req->length = (len == pending) ?
+		len + header_len : video->req_size;
+
+	/* Init the pending sgs with payload */
+	sg = sg_next(sg);
+
+	for_each_sg(sg, iter, ureq->sgt.nents - 1, i) {
+		if (!len || !buf->sg || !buf->sg->length)
+			break;
+
+		sg_left = buf->sg->length - buf->offset;
+		part = min_t(unsigned int, len, sg_left);
+
+		sg_set_page(iter, sg_page(buf->sg), part, buf->offset);
+
+		if (part == sg_left) {
+			buf->offset = 0;
+			buf->sg = sg_next(buf->sg);
+		} else {
+			buf->offset += part;
+		}
+		len -= part;
+	}
+
+	/* Assign the video data with header. */
+	req->buf = NULL;
+	req->sg	= ureq->sgt.sgl;
+	req->num_sgs = i + 1;
+
+	req->length -= len;
+	video->queue.buf_used += req->length - header_len;
+
+	if (buf->bytesused == video->queue.buf_used || !buf->sg ||
+			video->queue.flags & UVC_QUEUE_DROP_INCOMPLETE) {
+		video->queue.buf_used = 0;
+		buf->state = UVC_BUF_STATE_DONE;
+		buf->offset = 0;
+		list_del(&buf->queue);
+		video->fid ^= UVC_STREAM_FID;
+		ureq->last_buf = buf;
+	}
+}
+
+static void
+uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video,
+		struct uvc_buffer *buf)
+{
+	void *mem = req->buf;
+	struct uvc_request *ureq = req->context;
+	int len = video->req_size;
+	int ret;
+
+	/* Add the header. */
+	ret = uvc_video_encode_header(video, buf, mem, len);
+	mem += ret;
+	len -= ret;
+
+	/* Process video data. */
+	ret = uvc_video_encode_data(video, buf, mem, len);
+	len -= ret;
+
+	req->length = video->req_size - len;
+
+	if (buf->bytesused == video->queue.buf_used ||
+			video->queue.flags & UVC_QUEUE_DROP_INCOMPLETE) {
+		video->queue.buf_used = 0;
+		buf->state = UVC_BUF_STATE_DONE;
+		list_del(&buf->queue);
+		video->fid ^= UVC_STREAM_FID;
+		ureq->last_buf = 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)
+{
+	sg_free_table(&ureq->sgt);
+	if (ureq->req && ep) {
+		usb_ep_free_request(ep, ureq->req);
+		ureq->req = NULL;
+	}
+
+	kfree(ureq->req_buffer);
+	ureq->req_buffer = NULL;
+
+	if (!list_empty(&ureq->list))
+		list_del_init(&ureq->list);
+
+	kfree(ureq);
+}
+
+static int uvcg_video_ep_queue(struct uvc_video *video, struct usb_request *req)
+{
+	int ret;
+
+	ret = usb_ep_queue(video->ep, req, GFP_ATOMIC);
+	if (ret < 0) {
+		uvcg_err(&video->uvc->func, "Failed to queue request (%d).\n",
+			 ret);
+
+		/* If the endpoint is disabled the descriptor may be NULL. */
+		if (video->ep->desc) {
+			/* Isochronous endpoints can't be halted. */
+			if (usb_endpoint_xfer_bulk(video->ep->desc))
+				usb_ep_set_halt(video->ep);
+		}
+	}
+
+	return ret;
+}
+
+/* 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)
+{
+	bool is_bulk = video->max_payload_size;
+	struct list_head *list = NULL;
+
+	if (!video->is_enabled)
+		return -ENODEV;
+
+	if (queue_to_ep) {
+		struct uvc_request *ureq = req->context;
+		/*
+		 * With USB3 handling more requests at a higher speed, we can't
+		 * afford to generate an interrupt for every request. Decide to
+		 * interrupt:
+		 *
+		 * - When no more requests are available in the free queue, as
+		 *   this may be our last chance to refill the endpoint's
+		 *   request queue.
+		 *
+		 * - When this is request is the last request for the video
+		 *   buffer, as we want to start sending the next video buffer
+		 *   ASAP in case it doesn't get started already in the next
+		 *   iteration of this loop.
+		 *
+		 * - Four times over the length of the requests queue (as
+		 *   indicated by video->uvc_num_requests), as a trade-off
+		 *   between latency and interrupt load.
+		 */
+		if (list_empty(&video->req_free) || ureq->last_buf ||
+			!(video->req_int_count %
+			DIV_ROUND_UP(video->uvc_num_requests, 4))) {
+			video->req_int_count = 0;
+			req->no_interrupt = 0;
+		} else {
+			req->no_interrupt = 1;
+		}
+		video->req_int_count++;
+		return uvcg_video_ep_queue(video, req);
+	}
+	/*
+	 * If we're not queuing to the ep, for isoc we're queuing
+	 * to the req_ready list, otherwise req_free.
+	 */
+	list = is_bulk ? &video->req_free : &video->req_ready;
+	list_add_tail(&req->list, list);
+	return 0;
+}
+
+/*
+ * 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)
+{
+	struct usb_request *req = NULL;
+	unsigned long flags = 0;
+	unsigned int count = 0;
+	int ret = 0;
+
+	/*
+	 * We only queue half of the free list since we still want to have
+	 * some free usb_requests in the free list for the video_pump async_wq
+	 * thread to encode uvc buffers into. Otherwise we could get into a
+	 * situation where the free list does not have any usb requests to
+	 * encode into - we always end up queueing 0 length requests to the
+	 * end point.
+	 */
+	unsigned int half_list_size = video->uvc_num_requests / 2;
+
+	spin_lock_irqsave(&video->req_lock, flags);
+	/*
+	 * Take these requests off the free list and queue them all to the
+	 * endpoint. Since we queue 0 length requests with the req_lock held,
+	 * there isn't any 'data' race involved here with the complete handler.
+	 */
+	while (count < half_list_size) {
+		req = list_first_entry(&video->req_free, struct usb_request,
+					list);
+		list_del(&req->list);
+		req->length = 0;
+		ret = uvcg_video_ep_queue(video, req);
+		if (ret < 0) {
+			uvcg_queue_cancel(&video->queue, 0);
+			break;
+		}
+		count++;
+	}
+	spin_unlock_irqrestore(&video->req_lock, flags);
+}
+
+static void
+uvc_video_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	struct uvc_request *ureq = req->context;
+	struct uvc_video *video = ureq->video;
+	struct uvc_video_queue *queue = &video->queue;
+	struct uvc_buffer *last_buf;
+	unsigned long flags;
+	bool is_bulk = video->max_payload_size;
+	int ret = 0;
+
+	spin_lock_irqsave(&video->req_lock, flags);
+	if (!video->is_enabled) {
+		/*
+		 * When is_enabled is false, uvcg_video_disable() ensures
+		 * that in-flight uvc_buffers are returned, so we can
+		 * safely call free_request without worrying about
+		 * last_buf.
+		 */
+		uvc_video_free_request(ureq, ep);
+		spin_unlock_irqrestore(&video->req_lock, flags);
+		return;
+	}
+
+	last_buf = ureq->last_buf;
+	ureq->last_buf = NULL;
+	spin_unlock_irqrestore(&video->req_lock, flags);
+
+	switch (req->status) {
+	case 0:
+		break;
+
+	case -EXDEV:
+		uvcg_dbg(&video->uvc->func, "VS request missed xfer.\n");
+		queue->flags |= UVC_QUEUE_DROP_INCOMPLETE;
+		break;
+
+	case -ESHUTDOWN:	/* disconnect from host. */
+		uvcg_dbg(&video->uvc->func, "VS request cancelled.\n");
+		uvcg_queue_cancel(queue, 1);
+		break;
+
+	default:
+		uvcg_warn(&video->uvc->func,
+			  "VS request completed with status %d.\n",
+			  req->status);
+		uvcg_queue_cancel(queue, 0);
+	}
+
+	if (last_buf) {
+		spin_lock_irqsave(&queue->irqlock, flags);
+		uvcg_complete_buffer(queue, last_buf);
+		spin_unlock_irqrestore(&queue->irqlock, flags);
+	}
+
+	spin_lock_irqsave(&video->req_lock, flags);
+	/*
+	 * Video stream might have been disabled while we were
+	 * processing the current usb_request. So make sure
+	 * we're still streaming before queueing the usb_request
+	 * back to req_free
+	 */
+	if (video->is_enabled) {
+		/*
+		 * Here we check whether any request is available in the ready
+		 * list. If it is, queue it to the ep and add the current
+		 * usb_request to the req_free list - for video_pump to fill in.
+		 * Otherwise, just use the current usb_request to queue a 0
+		 * length request to the ep. Since we always add to the req_free
+		 * list if we dequeue from the ready list, there will never
+		 * be a situation where the req_free list is completely out of
+		 * requests and cannot recover.
+		 */
+		struct usb_request *to_queue = req;
+
+		to_queue->length = 0;
+		if (!list_empty(&video->req_ready)) {
+			to_queue = list_first_entry(&video->req_ready,
+				struct usb_request, list);
+			list_del(&to_queue->list);
+			list_add_tail(&req->list, &video->req_free);
+			/*
+			 * Queue work to the wq as well since it is possible that a
+			 * buffer may not have been completely encoded with the set of
+			 * in-flight usb requests for whih the complete callbacks are
+			 * firing.
+			 * In that case, if we do not queue work to the worker thread,
+			 * the buffer will never be marked as complete - and therefore
+			 * not be returned to userpsace. As a result,
+			 * dequeue -> queue -> dequeue flow of uvc buffers will not
+			 * happen.
+			 */
+			queue_work(video->async_wq, &video->pump);
+		}
+		/*
+		 * Queue to the endpoint. The actual queueing to ep will
+		 * only happen on one thread - the async_wq for bulk endpoints
+		 * and this thread for isoc endpoints.
+		 */
+		ret = uvcg_video_usb_req_queue(video, to_queue, !is_bulk);
+		if (ret < 0) {
+			/*
+			 * Endpoint error, but the stream is still enabled.
+			 * Put request back in req_free for it to be cleaned
+			 * up later.
+			 */
+			list_add_tail(&to_queue->list, &video->req_free);
+		}
+	} else {
+		uvc_video_free_request(ureq, ep);
+		ret = 0;
+	}
+	spin_unlock_irqrestore(&video->req_lock, flags);
+	if (ret < 0)
+		uvcg_queue_cancel(queue, 0);
+}
+
+static int
+uvc_video_free_requests(struct uvc_video *video)
+{
+	struct uvc_request *ureq, *temp;
+
+	list_for_each_entry_safe(ureq, temp, &video->ureqs, list)
+		uvc_video_free_request(ureq, video->ep);
+
+	INIT_LIST_HEAD(&video->ureqs);
+	INIT_LIST_HEAD(&video->req_free);
+	INIT_LIST_HEAD(&video->req_ready);
+	video->req_size = 0;
+	return 0;
+}
+
+static int
+uvc_video_alloc_requests(struct uvc_video *video)
+{
+	struct uvc_request *ureq;
+	unsigned int req_size;
+	unsigned int i;
+	int ret = -ENOMEM;
+
+	BUG_ON(video->req_size);
+
+	req_size = video->ep->maxpacket
+		 * max_t(unsigned int, video->ep->maxburst, 1)
+		 * (video->ep->mult);
+
+	for (i = 0; i < video->uvc_num_requests; i++) {
+		ureq = kzalloc(sizeof(struct uvc_request), GFP_KERNEL);
+		if (ureq == NULL)
+			goto error;
+
+		INIT_LIST_HEAD(&ureq->list);
+
+		list_add_tail(&ureq->list, &video->ureqs);
+
+		ureq->req_buffer = kmalloc(req_size, GFP_KERNEL);
+		if (ureq->req_buffer == NULL)
+			goto error;
+
+		ureq->req = usb_ep_alloc_request(video->ep, GFP_KERNEL);
+		if (ureq->req == NULL)
+			goto error;
+
+		ureq->req->buf = ureq->req_buffer;
+		ureq->req->length = 0;
+		ureq->req->complete = uvc_video_complete;
+		ureq->req->context = ureq;
+		ureq->video = video;
+		ureq->last_buf = NULL;
+
+		list_add_tail(&ureq->req->list, &video->req_free);
+		/* req_size/PAGE_SIZE + 1 for overruns and + 1 for header */
+		sg_alloc_table(&ureq->sgt,
+			       DIV_ROUND_UP(req_size - UVCG_REQUEST_HEADER_LEN,
+					    PAGE_SIZE) + 2, GFP_KERNEL);
+	}
+
+	video->req_size = req_size;
+
+	return 0;
+
+error:
+	uvc_video_free_requests(video);
+	return ret;
+}
+
+/* --------------------------------------------------------------------------
+ * 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)
+{
+	struct uvc_video *video = container_of(work, struct uvc_video, pump);
+	struct uvc_video_queue *queue = &video->queue;
+	/* video->max_payload_size is only set when using bulk transfer */
+	bool is_bulk = video->max_payload_size;
+	struct usb_request *req = NULL;
+	struct uvc_buffer *buf;
+	unsigned long flags;
+	int ret = 0;
+
+	while (true) {
+		if (!video->ep->enabled)
+			return;
+
+		/*
+		 * Check is_enabled and retrieve the first available USB
+		 * request, protected by the request lock.
+		 */
+		spin_lock_irqsave(&video->req_lock, flags);
+		if (!video->is_enabled || list_empty(&video->req_free)) {
+			spin_unlock_irqrestore(&video->req_lock, flags);
+			return;
+		}
+		req = list_first_entry(&video->req_free, struct usb_request,
+					list);
+		list_del(&req->list);
+		spin_unlock_irqrestore(&video->req_lock, flags);
+
+		/*
+		 * Retrieve the first available video buffer and fill the
+		 * request, protected by the video queue irqlock.
+		 */
+		spin_lock_irqsave(&queue->irqlock, flags);
+		buf = uvcg_queue_head(queue);
+
+		if (buf != NULL) {
+			video->encode(req, video, buf);
+		} else {
+			/*
+			 * Either the queue has been disconnected or no video buffer
+			 * available for bulk transfer. Either way, stop processing
+			 * further.
+			 */
+			spin_unlock_irqrestore(&queue->irqlock, flags);
+			break;
+		}
+
+		spin_unlock_irqrestore(&queue->irqlock, flags);
+
+		spin_lock_irqsave(&video->req_lock, flags);
+		/* For bulk end points we queue from the worker thread
+		 * since we would preferably not want to wait on requests
+		 * to be ready, in the uvcg_video_complete() handler.
+		 * For isoc endpoints we add the request to the ready list
+		 * and only queue it to the endpoint from the complete handler.
+		 */
+		ret = uvcg_video_usb_req_queue(video, req, is_bulk);
+		spin_unlock_irqrestore(&video->req_lock, flags);
+
+		if (ret < 0) {
+			uvcg_queue_cancel(queue, 0);
+			break;
+		}
+
+		/* The request is owned by  the endpoint / ready list. */
+		req = NULL;
+	}
+
+	if (!req)
+		return;
+
+	spin_lock_irqsave(&video->req_lock, flags);
+	if (video->is_enabled)
+		list_add_tail(&req->list, &video->req_free);
+	else
+		uvc_video_free_request(req->context, video->ep);
+	spin_unlock_irqrestore(&video->req_lock, flags);
+}
+
+/*
+ * Disable the video stream
+ */
+int
+uvcg_video_disable(struct uvc_video *video)
+{
+	unsigned long flags;
+	struct list_head inflight_bufs;
+	struct usb_request *req, *temp;
+	struct uvc_buffer *buf, *btemp;
+	struct uvc_request *ureq, *utemp;
+
+	if (video->ep == NULL) {
+		uvcg_info(&video->uvc->func,
+			  "Video disable failed, device is uninitialized.\n");
+		return -ENODEV;
+	}
+
+	INIT_LIST_HEAD(&inflight_bufs);
+	spin_lock_irqsave(&video->req_lock, flags);
+	video->is_enabled = false;
+
+	/*
+	 * Remove any in-flight buffers from the uvc_requests
+	 * because we want to return them before cancelling the
+	 * queue. This ensures that we aren't stuck waiting for
+	 * all complete callbacks to come through before disabling
+	 * vb2 queue.
+	 */
+	list_for_each_entry(ureq, &video->ureqs, list) {
+		if (ureq->last_buf) {
+			list_add_tail(&ureq->last_buf->queue, &inflight_bufs);
+			ureq->last_buf = NULL;
+		}
+	}
+	spin_unlock_irqrestore(&video->req_lock, flags);
+
+	cancel_work_sync(&video->pump);
+	uvcg_queue_cancel(&video->queue, 0);
+
+	spin_lock_irqsave(&video->req_lock, flags);
+	/*
+	 * Remove all uvc_requests from ureqs with list_del_init
+	 * This lets uvc_video_free_request correctly identify
+	 * if the uvc_request is attached to a list or not when freeing
+	 * memory.
+	 */
+	list_for_each_entry_safe(ureq, utemp, &video->ureqs, list)
+		list_del_init(&ureq->list);
+
+	list_for_each_entry_safe(req, temp, &video->req_free, list) {
+		list_del(&req->list);
+		uvc_video_free_request(req->context, video->ep);
+	}
+
+	list_for_each_entry_safe(req, temp, &video->req_ready, list) {
+		list_del(&req->list);
+		uvc_video_free_request(req->context, video->ep);
+	}
+
+	INIT_LIST_HEAD(&video->ureqs);
+	INIT_LIST_HEAD(&video->req_free);
+	INIT_LIST_HEAD(&video->req_ready);
+	video->req_size = 0;
+	spin_unlock_irqrestore(&video->req_lock, flags);
+
+	/*
+	 * Return all the video buffers before disabling the queue.
+	 */
+	spin_lock_irqsave(&video->queue.irqlock, flags);
+	list_for_each_entry_safe(buf, btemp, &inflight_bufs, queue) {
+		list_del(&buf->queue);
+		uvcg_complete_buffer(&video->queue, buf);
+	}
+	spin_unlock_irqrestore(&video->queue.irqlock, flags);
+
+	uvcg_queue_enable(&video->queue, 0);
+	return 0;
+}
+
+/*
+ * Enable the video stream.
+ */
+int uvcg_video_enable(struct uvc_video *video)
+{
+	int ret;
+
+	if (video->ep == NULL) {
+		uvcg_info(&video->uvc->func,
+			  "Video enable failed, device is uninitialized.\n");
+		return -ENODEV;
+	}
+
+	/*
+	 * Safe to access request related fields without req_lock because
+	 * this is the only thread currently active, and no other
+	 * request handling thread will become active until this function
+	 * returns.
+	 */
+	video->is_enabled = true;
+
+	if ((ret = uvcg_queue_enable(&video->queue, 1)) < 0)
+		return ret;
+
+	if ((ret = uvc_video_alloc_requests(video)) < 0)
+		return ret;
+
+	if (video->max_payload_size) {
+		video->encode = uvc_video_encode_bulk;
+		video->payload_size = 0;
+	} else
+		video->encode = video->queue.use_sg ?
+			uvc_video_encode_isoc_sg : uvc_video_encode_isoc;
+
+	video->req_int_count = 0;
+
+	uvc_video_ep_queue_initial_requests(video);
+
+	return ret;
+}
+
+/*
+ * Initialize the UVC video stream.
+ */
+int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc)
+{
+	video->is_enabled = false;
+	INIT_LIST_HEAD(&video->ureqs);
+	INIT_LIST_HEAD(&video->req_free);
+	INIT_LIST_HEAD(&video->req_ready);
+	spin_lock_init(&video->req_lock);
+	INIT_WORK(&video->pump, uvcg_video_pump);
+
+	/* Allocate a work queue for asynchronous video pump handler. */
+	video->async_wq = alloc_workqueue("uvcgadget", WQ_UNBOUND | WQ_HIGHPRI, 0);
+	if (!video->async_wq)
+		return -EINVAL;
+
+	video->uvc = uvc;
+	video->fcc = V4L2_PIX_FMT_YUYV;
+	video->bpp = 16;
+	video->width = 320;
+	video->height = 240;
+	video->imagesize = 320 * 240 * 2;
+
+	/* Initialize the video buffers queue. */
+	uvcg_queue_init(&video->queue, uvc->v4l2_dev.dev->parent,
+			V4L2_BUF_TYPE_VIDEO_OUTPUT, &video->mutex);
+	return 0;
+}

drivers/usb/gadget/function/uvc-new/uvc_video.h

@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *	uvc_video.h  --  USB Video Class Gadget driver
+ *
+ * Copyright (C) 2009-2010
+ *		Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ *
+ * Copyright (c) 2013 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *		Author: Andrzej Pietrasiewicz <andrzejtp2010@gmail.com>
+ */
+#ifndef __UVC_VIDEO_H__
+#define __UVC_VIDEO_H__
+
+struct uvc_video;
+
+int uvcg_video_enable(struct uvc_video *video);
+int uvcg_video_disable(struct uvc_video *video);
+
+int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc);
+
+#endif /* __UVC_VIDEO_H__ */

include/uapi/linux/usb/g_uvc-new.h

@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ * g_uvc.h  --  USB Video Class Gadget driver API
+ *
+ * Copyright (C) 2009-2010 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ */
+
+#ifndef __LINUX_USB_G_UVC_H
+#define __LINUX_USB_G_UVC_H
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+#include <linux/usb/ch9.h>
+
+#define UVC_EVENT_FIRST			(V4L2_EVENT_PRIVATE_START + 0)
+#define UVC_EVENT_CONNECT		(V4L2_EVENT_PRIVATE_START + 0)
+#define UVC_EVENT_DISCONNECT		(V4L2_EVENT_PRIVATE_START + 1)
+#define UVC_EVENT_STREAMON		(V4L2_EVENT_PRIVATE_START + 2)
+#define UVC_EVENT_STREAMOFF		(V4L2_EVENT_PRIVATE_START + 3)
+#define UVC_EVENT_SETUP			(V4L2_EVENT_PRIVATE_START + 4)
+#define UVC_EVENT_DATA			(V4L2_EVENT_PRIVATE_START + 5)
+#define UVC_EVENT_LAST			(V4L2_EVENT_PRIVATE_START + 5)
+
+#define UVC_STRING_CONTROL_IDX			0
+#define UVC_STRING_STREAMING_IDX		1
+
+struct uvc_request_data {
+	__s32 length;
+	__u8 data[60];
+};
+
+struct uvc_event {
+	union {
+		enum usb_device_speed speed;
+		struct usb_ctrlrequest req;
+		struct uvc_request_data data;
+	};
+};
+
+#define UVCIOC_SEND_RESPONSE		_IOW('U', 1, struct uvc_request_data)
+
+#endif /* __LINUX_USB_G_UVC_H */