path: root/drivers/usb/gadget/function/f_uvc.c

// SPDX-License-Identifier: GPL-2.0+
/*
 *	uvc_gadget.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/fs.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/string.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/usb/g_uvc.h>
#include <linux/usb/video.h>
#include <linux/vmalloc.h>
#include <linux/wait.h>

#include <media/v4l2-dev.h>
#include <media/v4l2-event.h>

#include "uvc.h"
#include "uvc_configfs.h"
#include "uvc_v4l2.h"
#include "uvc_video.h"

unsigned int uvc_gadget_trace_param;
module_param_named(trace, uvc_gadget_trace_param, uint, 0644);
MODULE_PARM_DESC(trace, "Trace level bitmask");

/* --------------------------------------------------------------------------
 * Function descriptors
 */

/* string IDs are assigned dynamically */

static struct usb_string uvc_en_us_strings[] = {
	/* [UVC_STRING_CONTROL_IDX].s = DYNAMIC, */
	[UVC_STRING_STREAMING_IDX].s = "Video Streaming",
	{  }
};

static struct usb_gadget_strings uvc_stringtab = {
	.language = 0x0409,	/* en-us */
	.strings = uvc_en_us_strings,
};

static struct usb_gadget_strings *uvc_function_strings[] = {
	&uvc_stringtab,
	NULL,
};

#define UVC_INTF_VIDEO_CONTROL			0
#define UVC_INTF_VIDEO_STREAMING		1

#define UVC_STATUS_MAX_PACKET_SIZE		16	/* 16 bytes status */

static struct usb_interface_assoc_descriptor uvc_iad = {
	.bLength		= sizeof(uvc_iad),
	.bDescriptorType	= USB_DT_INTERFACE_ASSOCIATION,
	.bFirstInterface	= 0,
	.bInterfaceCount	= 2,
	.bFunctionClass		= USB_CLASS_VIDEO,
	.bFunctionSubClass	= UVC_SC_VIDEO_INTERFACE_COLLECTION,
	.bFunctionProtocol	= 0x00,
	.iFunction		= 0,
};

static struct usb_interface_descriptor uvc_control_intf = {
	.bLength		= USB_DT_INTERFACE_SIZE,
	.bDescriptorType	= USB_DT_INTERFACE,
	.bInterfaceNumber	= UVC_INTF_VIDEO_CONTROL,
	.bAlternateSetting	= 0,
	.bNumEndpoints		= 0,
	.bInterfaceClass	= USB_CLASS_VIDEO,
	.bInterfaceSubClass	= UVC_SC_VIDEOCONTROL,
	.bInterfaceProtocol	= 0x00,
	.iInterface		= 0,
};

static struct usb_endpoint_descriptor uvc_interrupt_ep = {
	.bLength		= USB_DT_ENDPOINT_SIZE,
	.bDescriptorType	= USB_DT_ENDPOINT,
	.bEndpointAddress	= USB_DIR_IN,
	.bmAttributes		= USB_ENDPOINT_XFER_INT,
	.wMaxPacketSize		= cpu_to_le16(UVC_STATUS_MAX_PACKET_SIZE),
	.bInterval		= 8,
};

static struct usb_ss_ep_comp_descriptor uvc_ss_interrupt_comp = {
	.bLength		= sizeof(uvc_ss_interrupt_comp),
	.bDescriptorType	= USB_DT_SS_ENDPOINT_COMP,
	/* The following 3 values can be tweaked if necessary. */
	.bMaxBurst		= 0,
	.bmAttributes		= 0,
	.wBytesPerInterval	= cpu_to_le16(UVC_STATUS_MAX_PACKET_SIZE),
};

static struct uvc_control_endpoint_descriptor uvc_interrupt_cs_ep = {
	.bLength		= UVC_DT_CONTROL_ENDPOINT_SIZE,
	.bDescriptorType	= USB_DT_CS_ENDPOINT,
	.bDescriptorSubType	= UVC_EP_INTERRUPT,
	.wMaxTransferSize	= cpu_to_le16(UVC_STATUS_MAX_PACKET_SIZE),
};

static struct usb_interface_descriptor uvc_streaming_intf_alt0 = {
	.bLength		= USB_DT_INTERFACE_SIZE,
	.bDescriptorType	= USB_DT_INTERFACE,
	.bInterfaceNumber	= UVC_INTF_VIDEO_STREAMING,
	.bAlternateSetting	= 0,
	.bNumEndpoints		= 0,
	.bInterfaceClass	= USB_CLASS_VIDEO,
	.bInterfaceSubClass	= UVC_SC_VIDEOSTREAMING,
	.bInterfaceProtocol	= 0x00,
	.iInterface		= 0,
};

static struct usb_interface_descriptor uvc_streaming_intf_alt1 = {
	.bLength		= USB_DT_INTERFACE_SIZE,
	.bDescriptorType	= USB_DT_INTERFACE,
	.bInterfaceNumber	= UVC_INTF_VIDEO_STREAMING,
	.bAlternateSetting	= 1,
	.bNumEndpoints		= 1,
	.bInterfaceClass	= USB_CLASS_VIDEO,
	.bInterfaceSubClass	= UVC_SC_VIDEOSTREAMING,
	.bInterfaceProtocol	= 0x00,
	.iInterface		= 0,
};

static struct usb_endpoint_descriptor uvc_fs_streaming_ep = {
	.bLength		= USB_DT_ENDPOINT_SIZE,
	.bDescriptorType	= USB_DT_ENDPOINT,
	.bEndpointAddress	= USB_DIR_IN,
	.bmAttributes		= USB_ENDPOINT_SYNC_ASYNC
				| USB_ENDPOINT_XFER_ISOC,
	/*
	 * The wMaxPacketSize and bInterval values will be initialized from
	 * module parameters.
	 */
};

static struct usb_endpoint_descriptor uvc_hs_streaming_ep = {
	.bLength		= USB_DT_ENDPOINT_SIZE,
	.bDescriptorType	= USB_DT_ENDPOINT,
	.bEndpointAddress	= USB_DIR_IN,
	.bmAttributes		= USB_ENDPOINT_SYNC_ASYNC
				| USB_ENDPOINT_XFER_ISOC,
	/*
	 * The wMaxPacketSize and bInterval values will be initialized from
	 * module parameters.
	 */
};

static struct usb_endpoint_descriptor uvc_ss_streaming_ep = {
	.bLength		= USB_DT_ENDPOINT_SIZE,
	.bDescriptorType	= USB_DT_ENDPOINT,

	.bEndpointAddress	= USB_DIR_IN,
	.bmAttributes		= USB_ENDPOINT_SYNC_ASYNC
				| USB_ENDPOINT_XFER_ISOC,
	/*
	 * The wMaxPacketSize and bInterval values will be initialized from
	 * module parameters.
	 */
};

static struct usb_ss_ep_comp_descriptor uvc_ss_streaming_comp = {
	.bLength		= sizeof(uvc_ss_streaming_comp),
	.bDescriptorType	= USB_DT_SS