path: root/drivers/usb/gadget/legacy/g_ffs.c

/*
 * g_ffs.c -- user mode file system API for USB composite function controllers
 *
 * Copyright (C) 2010 Samsung Electronics
 * Author: Michal Nazarewicz <mina86@mina86.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#define pr_fmt(fmt) "g_ffs: " fmt

#include <linux/module.h>

/* module parameters specific to the Video streaming endpoint */
static unsigned int streaming_interval = 1;
module_param(streaming_interval, uint, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(streaming_interval, "1 - 16");

static unsigned int streaming_maxpacket = 1024;
module_param(streaming_maxpacket, uint, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(streaming_maxpacket, "1 - 1023 (FS), 1 - 3072 (hs/ss)");

static unsigned int streaming_maxburst;
module_param(streaming_maxburst, uint, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(streaming_maxburst, "0 - 15 (ss only)");

static unsigned int trace;
module_param(trace, uint, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(trace, "Trace level bitmask");

#if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
#include <linux/netdevice.h>

#  if defined USB_ETH_RNDIS
#    undef USB_ETH_RNDIS
#  endif
#  ifdef CONFIG_USB_FUNCTIONFS_RNDIS
#    define USB_ETH_RNDIS y
#  endif

#  include "u_ecm.h"
#  include "u_gether.h"
#  ifdef USB_ETH_RNDIS
#    include "u_rndis.h"
#    include "rndis.h"
#  endif
#  include "u_ether.h"

USB_ETHERNET_MODULE_PARAMETERS();

#  ifdef CONFIG_USB_FUNCTIONFS_ETH
static int eth_bind_config(struct usb_configuration *c);
static struct usb_function_instance *fi_ecm;
static struct usb_function *f_ecm;
static struct usb_function_instance *fi_geth;
static struct usb_function *f_geth;
#  endif
#  ifdef CONFIG_USB_FUNCTIONFS_RNDIS
static int bind_rndis_config(struct usb_configuration *c);
static struct usb_function_instance *fi_rndis;
static struct usb_function *f_rndis;
#  endif
#endif

#include "u_fs.h"
#if defined CONFIG_USB_FUNCTIONFS_WEBCAM
#include <linux/usb/video.h>
# include "u_uvc.h"

static struct usb_function_instance *fi_uvc;
static struct usb_function *f_uvc;

/* --------------------------------------------------------------------------
 * Device descriptor
 */

#define WEBCAM_VENDOR_ID		0x1d6b	/* Linux Foundation */
#define WEBCAM_PRODUCT_ID		0x0102	/* Webcam A/V gadget */
#define WEBCAM_DEVICE_BCD		0x0010	/* 0.10 */

DECLARE_UVC_HEADER_DESCRIPTOR(1);

static const struct UVC_HEADER_DESCRIPTOR(1) uvc_control_header = {
	.bLength		= UVC_DT_HEADER_SIZE(1),
	.bDescriptorType	= USB_DT_CS_INTERFACE,
	.bDescriptorSubType	= UVC_VC_HEADER,
	.bcdUVC			= cpu_to_le16(0x0100),
	.wTotalLength		= 0, /* dynamic */
	.dwClockFrequency	= cpu_to_le32(48000000),
	.bInCollection		= 0, /* dynamic */
	.baInterfaceNr[0]	= 0, /* dynamic */
};

static const struct uvc_camera_terminal_descriptor uvc_camera_terminal = {
	.bLength		= UVC_DT_CAMERA_TERMINAL_SIZE(0),
	.bDescriptorType	= USB_DT_CS_INTERFACE,
	.bDescriptorSubType	= UVC_VC_INPUT_TERMINAL,
	.bTerminalID		= 1,
	.wTerminalType		= cpu_to_le16(0x0201),
	.bAssocTerminal		= 0,
	.iTerminal		= 0,
	.wObjectiveFocalLengthMin	= cpu_to_le16(0),
	.wObjectiveFocalLengthMax	= cpu_to_le16(0),
	.wOcularFocalLength		= cpu_to_le16(0),
	.bControlSize		= 0,
};

static const struct uvc_processing_unit_descriptor uvc_processing = {
	.bLength		= UVC_DT_PROCESSING_UNIT_SIZE(0),
	.bDescriptorType	= USB_DT_CS_INTERFACE,
	.bDescriptorSubType	= UVC_VC_PROCESSING_UNIT,
	.bUnitID		= 2,
	.bSourceID		= 1,
	.wMaxMultiplier		= cpu_to_le16(16*1024),
	.bControlSize		= 0,
	.iProcessing		= 0,
};

static const struct uvc_output_terminal_descriptor uvc_output_terminal = {
	.bLength		= UVC_DT_OUTPUT_TERMINAL_SIZE,
	.bDescriptorType	= USB_DT_CS_INTERFACE,
	.bDescriptorSubType	= UVC_VC_OUTPUT_TERMINAL,
	.bTerminalID		= 3,
	.wTerminalType		= cpu_to_le16(0x0101),
	.bAssocTerminal		= 0,
	.bSourceID		= 2,
	.iTerminal		= 0,
};

DECLARE_UVC_INPUT_HEADER_DESCRIPTOR(0, 0);

static const struct UVC_INPUT_HEADER_DESCRIPTOR(0, 0) uvc_input_header = {
	.bLength		= UVC_DT_INPUT_HEADER_SIZE(0, 0),
	.bDescriptorType	= USB_DT_CS_INTERFACE,
	.bDescriptorSubType	= UVC_VS_INPUT_HEADER,
	.bNumFormats		= 1,
	.wTotalLength		= 0, /* dynamic */
	.bEndpointAddress	= 0, /* dynamic */
	.bmInfo			= 0,
	.bTerminalLink		= 3,
	.bStillCaptureMethod	= 0,
	.bTriggerSupport	= 0,
	.bTriggerUsage		= 0,
	.bControlSize		= 0,
};

static const struct uvc_format_mjpeg uvc_format_mjpg = {
	.bLength		= UVC_DT_FORMAT_MJPEG_SIZE,
	.bDescriptorType	= USB_DT_CS_INTERFACE,
	.bDescriptorSubType	= UVC_VS_FORMAT_MJPEG,
	.bFormatIndex		= 1,
	.bNumFrameDescriptors	= 3,
	.bmFlags		= 0,
	.bDefaultFrameIndex	= 3,
	.bAspectRatioX		= 0,
	.bAspectRatioY		= 0,
	.bmInterfaceFlags	= 0,
	.bCopyProtect		= 0,
};

DECLARE_UVC_FRAME_MJPEG(1);

static const struct UVC_FRAME_MJPEG(1) uvc_frame_mjpg_360p = {
	.bLength		= UVC_DT_FRAME_MJPEG_SIZE(1),
	.bDescriptorType	= USB_DT_CS_INTERFACE,
	.bDescriptorSubType	= UVC_VS_FRAME_MJPEG,
	.bFrameIndex		= 1,
	.bmCapabilities		= 0,
	.wWidth			= cpu_to_le16(640),
	.wHeight		= cpu_to_le16(360),
	.dwMinBitRate		= cpu_to_le32(18432000),
	.dwMaxBitRate		= cpu_to_le32(55296000),
	.dwMaxVideoFrameBufferSize	= cpu_to_le32(460800),
	.dwDefaultFrameInterval	= cpu_to_le32(333333),
	.bFrameIntervalType	= 1,
	.dwFrameInterval[0]	= cpu_to_le32(333333),
};

static const struct UVC_FRAME_MJPEG(1) uvc_frame_mjpg_720p = {
	.bLength		= UVC_DT_FRAME_MJPEG_SIZE(1),
	.bDescriptorType	= USB_DT_CS_INTERFACE,
	.bDescriptorSubType	= UVC_VS_FRAME_MJPEG,
	.bFrameIndex		= 2,
	.bmCapabilities		= 0,
	.wWidth			= cpu_to_le16(1280),
	.wHeight		= cpu_to_le16(720),
	.dwMinBitRate		= cpu_to_le32(29491200),
	.dwMaxBitRate		= cpu_to_le32(29491200),
	.dwMaxVideoFrameBufferSize	= cpu_to_le32(1843200),
	.dwDefaultFrameInterval	= cpu_to_le32(333333),
	.bFrameIntervalType	= 1,
	.dwFrameInterval[0]	= cpu_to_le32(333333),
};

static const struct UVC_FRAME_MJPEG(1) uvc_frame_mjpg_1080p = {
	.bLength		= UVC_DT_FRAME_MJPEG_SIZE(1),
	.bDescriptorType	= USB_DT_CS_INTERFACE,
	.bDescriptorSubType	= UVC_VS_FRAME_MJPEG,
	.bFrameIndex		= 3,
	.bmCapabilities		= 0,
	.wWidth			= cpu_to_le16(1920),
	.wHeight		= cpu_to_le16(1080),
	.dwMinBitRate		= cpu_to_le32(66355200),
	.dwMaxBitRate		= cpu_to_le32(66355200),
	.dwMaxVideoFrameBufferSize	= cpu_to_le32(4147200),
	.dwDefaultFrameInterval	= cpu_to_le32(333333),
	.bFrameIntervalType	= 1,
	.dwFrameInterval[0]	= cpu_to_le32(333333),
};


static const struct uvc_color_matching_descriptor uvc_color_matching = {
	.bLength		= UVC_DT_COLOR_MATCHING_SIZE,
	.bDescriptorType	= USB_DT_CS_INTERFACE,
	.bDescriptorSubType	= UVC_VS_COLORFORMAT,
	.bColorPrimaries	= 1,
	.bTransferCharacteristics	= 1,
	.bMatrixCoefficients	= 4,
};

static const struct uvc_descriptor_header * const uvc_fs_control_cls[] = {
	(const struct uvc_descriptor_header *) &uvc_control_header,
	(const struct uvc_descriptor_header *) &uvc_camera_terminal,
	(const struct uvc_descriptor_header *) &uvc_processing,
	(const struct uvc_descriptor_header *) &uvc_output_terminal,
	NULL,
};

static const struct uvc_descriptor_header * const uvc_ss_control_cls[] = {
	(const struct uvc_descriptor_header *) &uvc_control_header,
	(const struct uvc_descriptor_header *) &uvc_camera_terminal,
	(const struct uvc_descriptor_header *) &uvc_processing,
	(const struct uvc_descriptor_header *) &uvc_output_terminal,
	NULL,
};

static const struct uvc_descriptor_header * const uvc_fs_streaming_cls[] = {
	(const struct uvc_descriptor_header *) &uvc_input_header,
	(const struct uvc_descriptor_header *) &uvc_format_mjpg,
	(const struct uvc_descriptor_header *) &uvc_frame_mjpg_360p,
	(const struct uvc_descriptor_header *) &uvc_frame_mjpg_720p,
	(const struct uvc_descriptor_header *) &uvc_frame_mjpg_1080p,
	(const struct uvc_descriptor_header *) &uvc_color_matching,
	NULL,
};

static const struct uvc_descriptor_header * const uvc_hs_streaming_cls[] = {
	(const struct uvc_descriptor_header *) &uvc_input_header,
	(const struct uvc_descriptor_header *) &uvc_format_mjpg,
	(const struct uvc_descriptor_header *) &uvc_frame_mjpg_360p,
	(const struct uvc_descriptor_header *) &uvc_frame_mjpg_720p,
	(const struct uvc_descriptor_header *) &uvc_frame_mjpg_1080p,
	(const struct uvc_descriptor_header *) &uvc_color_matching,
	NULL,
};

static const struct uvc_descriptor_header * const uvc_ss_streaming_cls[] = {
	(const struct uvc_descriptor_header *) &uvc_input_header,
	(const struct uvc_descriptor_header *) &uvc_format_mjpg,
	(const struct uvc_descriptor_header *) &uvc_frame_mjpg_360p,
	(const struct uvc_descriptor_header *) &uvc_frame_mjpg_720p,
	(const struct uvc_descriptor_header *) &uvc_frame_mjpg_1080p,
	(const struct uvc_descriptor_header *) &uvc_color_matching,
	NULL,
};

/* --------------------------------------------------------------------------
 * USB configuration
 */

static int
cam_config_bind(struct usb_configuration *c)
{
	int status = 0;

	f_uvc = usb_get_function(fi_uvc);
	if (IS_ERR(f_uvc))
		return PTR_ERR(f_uvc);

	status = usb_add_function(c, f_uvc);
	if (status < 0)
		usb_put_function(f_uvc);

	return status;
}

#endif

#define DRIVER_NAME	"g_ffs"
#define DRIVER_DESC	"USB Function Filesystem"
#define DRIVER_VERSION	"24 Aug 2004"

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Michal Nazarewicz");
MODULE_LICENSE("GPL");

#define GFS_VENDOR_ID	0x1d6b	/* Linux Foundation */
#define GFS_PRODUCT_ID	0x0105	/* FunctionFS Gadget */

#define GFS_MAX_DEVS	10

USB_GADGET_COMPOSITE_OPTIONS();

static struct usb_device_descriptor gfs_dev_desc = {
	.bLength		= sizeof gfs_dev_desc,
	.bDescriptorType	= USB_DT_DEVICE,

	.bcdUSB			= cpu_to_le16(0x0200),
	.bDeviceClass		= USB_CLASS_PER_INTERFACE,

	.idVendor		= cpu_to_le16(GFS_VENDOR_ID),
	.idProduct		= cpu_to_le16(GFS_PRODUCT_ID),
};

static char *func_names[GFS_MAX_DEVS];
static unsigned int func_num;

module_param_named(bDeviceClass,    gfs_dev_desc.bDeviceClass,    byte,   0644);
MODULE_PARM_DESC(bDeviceClass, "USB Device class");
module_param_named(bDeviceSubClass, gfs_dev_desc.bDeviceSubClass, byte,   0644);
MODULE_PARM_DESC(bDeviceSubClass, "USB Device subclass");
module_param_named(bDeviceProtocol, gfs_dev_desc.bDeviceProtocol, byte,   0644);
MODULE_PARM_DESC(bDeviceProtocol, "USB Device protocol");
module_param_array_named(functions, func_names, charp, &func_num, 0);
MODULE_PARM_DESC(functions, "USB Functions list");

static const struct usb_descriptor_header *gfs_otg_desc[] = {
	(const struct usb_descriptor_header *)
	&(const struct usb_otg_descriptor) {
		.bLength		= sizeof(struct usb_otg_descriptor),
		.bDescriptorType	= USB_DT_OTG,

		/*
		 * REVISIT SRP-only hardware is possible, although
		 * it would not be called "OTG" ...
		 */
		.bmAttributes		= USB_OTG_SRP | USB_OTG_HNP,
	},

	NULL
};

/* String IDs are assigned dynamically */
static struct usb_string gfs_strings[] = {
	[USB_GADGET_MANUFACTURER_IDX].s = "",
	[USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
	[USB_GADGET_SERIAL_IDX].s = "",
#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
	{ .s = "FunctionFS + RNDIS" },
#endif
#ifdef CONFIG_USB_FUNCTIONFS_ETH
	{ .s = "FunctionFS + ECM" },
#endif
#ifdef CONFIG_USB_FUNCTIONFS_WEBCAM
	{ .s = "FunctionFS + Webcam" },
#endif
#ifdef CONFIG_USB_FUNCTIONFS_GENERIC
	{ .s = "FunctionFS" },
#endif
	{  } /* end of list */
};

static struct usb_gadget_strings *gfs_dev_strings[] = {
	&(struct usb_gadget_strings) {
		.language	= 0x0409,	/* en-us */
		.strings	= gfs_strings,
	},
	NULL,
};

struct gfs_configuration {
	struct usb_configuration c;
	int (*eth)(struct usb_configuration *c);
	int num;
#ifdef CONFIG_USB_FUNCTIONFS_WEBCAM
	int (*webcam)(struct usb_configuration *c);
#endif
} gfs_configurations[] = {
#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
	{
		.eth		= bind_rndis_config,
	},
#endif

#ifdef CONFIG_USB_FUNCTIONFS_ETH
	{
		.eth		= eth_bind_config,
	},
#endif

#ifdef CONFIG_USB_FUNCTIONFS_WEBCAM
	{
		.webcam		= cam_config_bind,
	},
#endif

#ifdef CONFIG_USB_FUNCTIONFS_GENERIC
	{
	},
#endif
};

static void *functionfs_acquire_dev(struct ffs_dev *dev);
static void functionfs_release_dev(struct ffs_dev *dev);
static int functionfs_ready_callback(struct ffs_data *ffs);
static void functionfs_closed_callback(struct ffs_data *ffs);
static int gfs_bind(struct usb_composite_dev *cdev);
static int gfs_unbind(struct usb_composite_dev *cdev);
static int gfs_do_config(struct usb_configuration *c);


static __refdata struct usb_composite_driver gfs_driver = {
	.name		= DRIVER_NAME,
	.dev		= &gfs_dev_desc,
	.strings	= gfs_dev_strings,
	.max_speed	= USB_SPEED_HIGH,
	.bind		= gfs_bind,
	.unbind		= gfs_unbind,
};

static unsigned int missing_funcs;
static bool gfs_registered;
static bool gfs_single_func;
static struct usb_function_instance **fi_ffs;
static struct usb_function **f_ffs[] = {
#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
	NULL,
#endif

#ifdef CONFIG_USB_FUNCTIONFS_ETH
	NULL,
#endif

#ifdef CONFIG_USB_FUNCTIONFS_WEBCAM
	NULL,
#endif

#ifdef CONFIG_USB_FUNCTIONFS_GENERIC
	NULL,
#endif

};

#define N_CONF ARRAY_SIZE(f_ffs)

static int __init gfs_init(void)
{
	struct f_fs_opts *opts;
	int i;
	int ret = 0;

	ENTER();

	if (func_num < 2) {
		gfs_single_func = true;
		func_num = 1;
	}

	/*
	 * Allocate in one chunk for easier maintenance
	 */
	f_ffs[0] = kcalloc(func_num * N_CONF, sizeof(*f_ffs), GFP_KERNEL);
	if (!f_ffs[0]) {
		ret = -ENOMEM;
		goto no_func;
	}
	for (i = 1; i < N_CONF; ++i)
		f_ffs[i] = f_ffs[0] + i * func_num;

	fi_ffs = kcalloc(func_num, sizeof(*fi_ffs), GFP_KERNEL);
	if (!fi_ffs) {
		ret = -ENOMEM;
		goto no_func;
	}

	for (i = 0; i < func_num; i++) {
		fi_ffs[i] = usb_get_function_instance("ffs");
		if (IS_ERR(fi_ffs[i])) {
			ret = PTR_ERR(fi_ffs[i]);
			--i;
			goto no_dev;
		}
		opts = to_f_fs_opts(fi_ffs[i]);
		if (gfs_single_func)
			ret = ffs_single_dev(opts->dev);
		else
			ret = ffs_name_dev(opts->dev, func_names[i]);
		if (ret)
			goto no_dev;
		opts->dev->ffs_ready_callback = functionfs_ready_callback;
		opts->dev->ffs_closed_callback = functionfs_closed_callback;
		opts->dev->ffs_acquire_dev_callback = functionfs_acquire_dev;
		opts->dev->ffs_release_dev_callback = functionfs_release_dev;
		opts->no_configfs = true;
	}

	missing_funcs = func_num;

	return 0;
no_dev:
	while (i >= 0)
		usb_put_function_instance(fi_ffs[i--]);
	kfree(fi_ffs);
no_func:
	kfree(f_ffs[0]);
	return ret;
}
module_init(gfs_init);

static void __exit gfs_exit(void)
{
	int i;

	ENTER();

	if (gfs_registered)
		usb_composite_unregister(&gfs_driver);
	gfs_registered = false;

	kfree(f_ffs[0]);

	for (i = 0; i < func_num; i++)
		usb_put_function_instance(fi_ffs[i]);

	kfree(fi_ffs);
}
module_exit(gfs_exit);

static void *functionfs_acquire_dev(struct ffs_dev *dev)
{
	if (!try_module_get(THIS_MODULE))
		return ERR_PTR(-ENOENT);
	
	return 0;
}

static void functionfs_release_dev(struct ffs_dev *dev)
{
	module_put(THIS_MODULE);
}

/*
 * The caller of this function takes ffs_lock 
 */
static int functionfs_ready_callback(struct ffs_data *ffs)
{
	int ret = 0;

	if (--missing_funcs)
		return 0;

	if (gfs_registered)
		return -EBUSY;

	gfs_registered = true;

	ret = usb_composite_probe(&gfs_driver);
	if (unlikely(ret < 0))
		gfs_registered = false;
	
	return ret;
}

/*
 * The caller of this function takes ffs_lock 
 */
static void functionfs_closed_callback(struct ffs_data *ffs)
{
	missing_funcs++;

	if (gfs_registered)
		usb_composite_unregister(&gfs_driver);
	gfs_registered = false;
}

/*
 * It is assumed that gfs_bind is called from a context where ffs_lock is held
 */
static int gfs_bind(struct usb_composite_dev *cdev)
{
#if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
	struct net_device *net;
#endif
#if defined CONFIG_USB_FUNCTIONFS_WEBCAM
	struct f_uvc_opts *uvc_opts;
#endif
	int ret, i;

	ENTER();

	if (missing_funcs)
		return -ENODEV;
#if defined CONFIG_USB_FUNCTIONFS_ETH
	if (can_support_ecm(cdev->gadget)) {
		struct f_ecm_opts *ecm_opts;

		fi_ecm = usb_get_function_instance("ecm");
		if (IS_ERR(fi_ecm))
			return PTR_ERR(fi_ecm);
		ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);
		net = ecm_opts->net;
	} else {
		struct f_gether_opts *geth_opts;

		fi_geth = usb_get_function_instance("geth");
		if (IS_ERR(fi_geth))
			return PTR_ERR(fi_geth);
		geth_opts = container_of(fi_geth, struct f_gether_opts,
					 func_inst);
		net = geth_opts->net;
	}
#endif

#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
	{
		struct f_rndis_opts *rndis_opts;

		fi_rndis = usb_get_function_instance("rndis");
		if (IS_ERR(fi_rndis)) {
			ret = PTR_ERR(fi_rndis);
			goto error;
		}
		rndis_opts = container_of(fi_rndis, struct f_rndis_opts,
					  func_inst);
#ifndef CONFIG_USB_FUNCTIONFS_ETH
		net = rndis_opts->net;
#endif
	}
#endif

#if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
	gether_set_qmult(net, qmult);
	if (!gether_set_host_addr(net, host_addr))
		pr_info("using host ethernet address: %s", host_addr);
	if (!gether_set_dev_addr(net, dev_addr))
		pr_info("using self ethernet address: %s", dev_addr);
#endif

#if defined CONFIG_USB_FUNCTIONFS_RNDIS && defined CONFIG_USB_FUNCTIONFS_ETH
	gether_set_gadget(net, cdev->gadget);
	ret = gether_register_netdev(net);
	if (ret)
		goto error_rndis;

	if (can_support_ecm(cdev->gadget)) {
		struct f_ecm_opts *ecm_opts;

		ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);
		ecm_opts->bound = true;
	} else {
		struct f_gether_opts *geth_opts;

		geth_opts = container_of(fi_geth, struct f_gether_opts,
					 func_inst);
		geth_opts->bound = true;
	}

	rndis_borrow_net(fi_rndis, net);
#endif

#if defined CONFIG_USB_FUNCTIONFS_WEBCAM
	fi_uvc = usb_get_function_instance("uvc");
	if (IS_ERR(fi_uvc))
		goto error_webcam;

	uvc_opts = container_of(fi_uvc, struct f_uvc_opts, func_inst);

	uvc_opts->streaming_interval = streaming_interval;
	uvc_opts->streaming_maxpacket = streaming_maxpacket;
	uvc_opts->streaming_maxburst = streaming_maxburst;
	uvc_set_trace_param(trace);

	uvc_opts->fs_control = uvc_fs_control_cls;
	uvc_opts->ss_control = uvc_ss_control_cls;
	uvc_opts->fs_streaming = uvc_fs_streaming_cls;
	uvc_opts->hs_streaming = uvc_hs_streaming_cls;
	uvc_opts->ss_streaming = uvc_ss_streaming_cls;
#endif

	/* TODO: gstrings_attach? */
	ret = usb_string_ids_tab(cdev, gfs_strings);
	if (unlikely(ret < 0))
		goto error_rndis;
	gfs_dev_desc.iProduct = gfs_strings[USB_GADGET_PRODUCT_IDX].id;

	for (i = 0; i < ARRAY_SIZE(gfs_configurations); ++i) {
		struct gfs_configuration *c = gfs_configurations + i;
		int sid = USB_GADGET_FIRST_AVAIL_IDX + i;

		c->c.label			= gfs_strings[sid].s;
		c->c.iConfiguration		= gfs_strings[sid].id;
		c->c.bConfigurationValue	= 1 + i;
		c->c.bmAttributes		= USB_CONFIG_ATT_SELFPOWER;

		c->num = i;

		ret = usb_add_config(cdev, &c->c, gfs_do_config);
		if (unlikely(ret < 0))
			goto error_unbind;
	}
	usb_composite_overwrite_options(cdev, &coverwrite);
	return 0;

/* TODO */
error_unbind:
error_webcam:
#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
	if (!IS_ERR_OR_NULL(f_uvc))
		usb_put_function(f_uvc);
	if (!IS_ERR_OR_NULL(fi_uvc))
		usb_put_function_instance(fi_uvc);
#endif
error_rndis:
#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
	usb_put_function_instance(fi_rndis);
error:
#endif
#if defined CONFIG_USB_FUNCTIONFS_ETH
	if (can_support_ecm(cdev->gadget))
		usb_put_function_instance(fi_ecm);
	else
		usb_put_function_instance(fi_geth);
#endif
	return ret;
}

/*
 * It is assumed that gfs_unbind is called from a context where ffs_lock is held
 */
static int gfs_unbind(struct usb_composite_dev *cdev)
{
	int i;

	ENTER();


#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
	usb_put_function(f_rndis);
	usb_put_function_instance(fi_rndis);
#endif

#if defined CONFIG_USB_FUNCTIONFS_ETH
	if (can_support_ecm(cdev->gadget)) {
		usb_put_function(f_ecm);
		usb_put_function_instance(fi_ecm);
	} else {
		usb_put_function(f_geth);
		usb_put_function_instance(fi_geth);
	}
#endif


#if defined CONFIG_USB_FUNCTIONFS_WEBCAM
	if (!IS_ERR_OR_NULL(f_uvc))
		usb_put_function(f_uvc);
	if (!IS_ERR_OR_NULL(fi_uvc))
		usb_put_function_instance(fi_uvc);
#endif
	for (i = 0; i < N_CONF * func_num; ++i)
		usb_put_function(*(f_ffs[0] + i));

	return 0;
}

/*
 * It is assumed that gfs_do_config is called from a context where
 * ffs_lock is held
 */
static int gfs_do_config(struct usb_configuration *c)
{
	struct gfs_configuration *gc =
		container_of(c, struct gfs_configuration, c);
	int i;
	int ret;

	if (missing_funcs)
		return -ENODEV;

	if (gadget_is_otg(c->cdev->gadget)) {
		c->descriptors = gfs_otg_desc;
		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
	}

	if (gc->eth) {
		ret = gc->eth(c);
		if (unlikely(ret < 0))
			return ret;
	}

	for (i = 0; i < func_num; i++) {
		f_ffs[gc->num][i] = usb_get_function(fi_ffs[i]);
		if (IS_ERR(f_ffs[gc->num][i])) {
			ret = PTR_ERR(f_ffs[gc->num][i]);
			goto error;
		}
		ret = usb_add_function(c, f_ffs[gc->num][i]);
		if (ret < 0) {
			usb_put_function(f_ffs[gc->num][i]);
			goto error;
		}

#if defined CONFIG_USB_FUNCTIONFS_WEBCAM
		if (gc->webcam && i == 0) {
			ret = gc->webcam(c);
			if (unlikely(ret < 0))
				return ret;
		}
#endif
	}

	/*
	 * After previous do_configs there may be some invalid
	 * pointers in c->interface array.  This happens every time
	 * a user space function with fewer interfaces than a user
	 * space function that was run before the new one is run.  The
	 * compasit's set_config() assumes that if there is no more
	 * then MAX_CONFIG_INTERFACES interfaces in a configuration
	 * then there is a NULL pointer after the last interface in
	 * c->interface array.  We need to make sure this is true.
	 */
	if (c->next_interface_id < ARRAY_SIZE(c->interface))
		c->interface[c->next_interface_id] = NULL;

	return 0;
error:
	while (--i >= 0) {
		if (!IS_ERR(f_ffs[gc->num][i]))
			usb_remove_function(c, f_ffs[gc->num][i]);
		usb_put_function(f_ffs[gc->num][i]);
	}
	return ret;
}

#ifdef CONFIG_USB_FUNCTIONFS_ETH

static int eth_bind_config(struct usb_configuration *c)
{
	int status = 0;

	if (can_support_ecm(c->cdev->gadget)) {
		f_ecm = usb_get_function(fi_ecm);
		if (IS_ERR(f_ecm))
			return PTR_ERR(f_ecm);

		status = usb_add_function(c, f_ecm);
		if (status < 0)
			usb_put_function(f_ecm);

	} else {
		f_geth = usb_get_function(fi_geth);
		if (IS_ERR(f_geth))
			return PTR_ERR(f_geth);

		status = usb_add_function(c, f_geth);
		if (status < 0)
			usb_put_function(f_geth);
	}
	return status;
}

#endif

#ifdef CONFIG_USB_FUNCTIONFS_RNDIS

static int bind_rndis_config(struct usb_configuration *c)
{
	int status = 0;

	f_rndis = usb_get_function(fi_rndis);
	if (IS_ERR(f_rndis))
		return PTR_ERR(f_rndis);

	status = usb_add_function(c, f_rndis);
	if (status < 0)
		usb_put_function(f_rndis);

	return status;
}

#endif