text: # SPDX-License-Identifier: GPL-2.0
  #
  # USB Gadget support on a system involves
  #    (a) a peripheral controller, and
  #    (b) the gadget driver using it.
  #
  # NOTE:  Gadget support ** DOES NOT ** depend on host-side CONFIG_USB !!
  #
  #  - Host systems (like PCs) need CONFIG_USB (with "A" jacks).
  #  - Peripherals (like PDAs) need CONFIG_USB_GADGET (with "B" jacks).
  #  - Some systems have both kinds of controllers.
  #
  # With help from a special transceiver and a "Mini-AB" jack, systems with
  # both kinds of controller can also support "USB On-the-Go" (CONFIG_USB_OTG).
  #
  # A Linux "Gadget Driver" talks to the USB Peripheral Controller
  # driver through the abstract "gadget" API.  Some other operating
  # systems call these "client" drivers, of which "class drivers"
  # are a subset (implementing a USB device class specification).
  # A gadget driver implements one or more USB functions using
  # the peripheral hardware.
  #
  # Gadget drivers are hardware-neutral, or "platform independent",
  # except that they sometimes must understand quirks or limitations
  # of the particular controllers they work with.  For example, when
  # a controller doesn't support alternate configurations or provide
  # enough of the right types of endpoints, the gadget driver might
  # not be able work with that controller, or might need to implement
  # a less common variant of a device class protocol.
  #
  # The available choices each represent a single precomposed USB
  # gadget configuration. In the device model, each option contains
  # both the device instantiation as a child for a USB gadget
  # controller, and the relevant drivers for each function declared
  # by the device.
  
  menu "USB Gadget precomposed configurations"
  
  config USB_ZERO
  	tristate "Gadget Zero (DEVELOPMENT)"
  	select USB_LIBCOMPOSITE
  	select USB_F_SS_LB
  	help
  	  Gadget Zero is a two-configuration device.  It either sinks and
  	  sources bulk data; or it loops back a configurable number of
  	  transfers.  It also implements control requests, for "chapter 9"
  	  conformance.  The driver needs only two bulk-capable endpoints, so
  	  it can work on top of most device-side usb controllers.  It's
  	  useful for testing, and is also a working example showing how
  	  USB "gadget drivers" can be written.
  
  	  Make this be the first driver you try using on top of any new
  	  USB peripheral controller driver.  Then you can use host-side
  	  test software, like the "usbtest" driver, to put your hardware
  	  and its driver through a basic set of functional tests.
  
  	  Gadget Zero also works with the host-side "usb-skeleton" driver,
  	  and with many kinds of host-side test software.  You may need
  	  to tweak product and vendor IDs before host software knows about
  	  this device, and arrange to select an appropriate configuration.
  
  	  Say "y" to link the driver statically, or "m" to build a
  	  dynamically linked module called "g_zero".
  
  config USB_ZERO_HNPTEST
  	bool "HNP Test Device"
  	depends on USB_ZERO && USB_OTG
  	help
  	  You can configure this device to enumerate using the device
  	  identifiers of the USB-OTG test device.  That means that when
  	  this gadget connects to another OTG device, with this one using
  	  the "B-Peripheral" role, that device will use HNP to let this
  	  one serve as the USB host instead (in the "B-Host" role).
  
  config USB_AUDIO
  	tristate "Audio Gadget"
  	depends on SND
  	select USB_LIBCOMPOSITE
  	select SND_PCM
  	select USB_F_UAC1 if (GADGET_UAC1 && !GADGET_UAC1_LEGACY)
  	select USB_F_UAC1_LEGACY if (GADGET_UAC1 && GADGET_UAC1_LEGACY)
  	select USB_F_UAC2 if !GADGET_UAC1
  	select USB_U_AUDIO if (USB_F_UAC2 || USB_F_UAC1)
  	help
  	  This Gadget Audio driver is compatible with USB Audio Class
  	  specification 2.0. It implements 1 AudioControl interface,
  	  1 AudioStreaming Interface each for USB-OUT and USB-IN.
  	  Number of channels, sample rate and sample size can be
  	  specified as module parameters.
  	  This driver doesn't expect any real Audio codec to be present
  	  on the device - the audio streams are simply sinked to and
  	  sourced from a virtual ALSA sound card created. The user-space
  	  application may choose to do whatever it wants with the data
  	  received from the USB Host and choose to provide whatever it
  	  wants as audio data to the USB Host.
  
  	  Say "y" to link the driver statically, or "m" to build a
  	  dynamically linked module called "g_audio".
  
  config GADGET_UAC1
  	bool "UAC 1.0"
  	depends on USB_AUDIO
  	help
  	  If you instead want older USB Audio Class specification 1.0 support
  	  with similar driver capabilities.
  
  config GADGET_UAC1_LEGACY
  	bool "UAC 1.0 (Legacy)"
  	depends on GADGET_UAC1
  	help
  	  If you instead want legacy UAC Spec-1.0 driver that also has audio
  	  paths hardwired to the Audio codec chip on-board and doesn't work
  	  without one.
  
  config USB_ETH
  	tristate "Ethernet Gadget (with CDC Ethernet support)"
  	depends on NET
  	select USB_LIBCOMPOSITE
  	select USB_U_ETHER
  	select USB_F_ECM
  	select USB_F_SUBSET
  	select CRC32
  	help
  	  This driver implements Ethernet style communication, in one of
  	  several ways:
  
  	   - The "Communication Device Class" (CDC) Ethernet Control Model.
  	     That protocol is often avoided with pure Ethernet adapters, in
  	     favor of simpler vendor-specific hardware, but is widely
  	     supported by firmware for smart network devices.
  
  	   - On hardware can't implement that protocol, a simple CDC subset
  	     is used, placing fewer demands on USB.
  
  	   - CDC Ethernet Emulation Model (EEM) is a newer standard that has
  	     a simpler interface that can be used by more USB hardware.
  
  	  RNDIS support is an additional option, more demanding than subset.
  
  	  Within the USB device, this gadget driver exposes a network device
  	  "usbX", where X depends on what other networking devices you have.
  	  Treat it like a two-node Ethernet link:  host, and gadget.
  
  	  The Linux-USB host-side "usbnet" driver interoperates with this
  	  driver, so that deep I/O queues can be supported.  On 2.4 kernels,
  	  use "CDCEther" instead, if you're using the CDC option. That CDC
  	  mode should also interoperate with standard CDC Ethernet class
  	  drivers on other host operating systems.
  
  	  Say "y" to link the driver statically, or "m" to build a
  	  dynamically linked module called "g_ether".
  
  config USB_ETH_RNDIS
  	bool "RNDIS support"
  	depends on USB_ETH
  	select USB_LIBCOMPOSITE
  	select USB_F_RNDIS
  	default y
  	help
  	   Microsoft Windows XP bundles the "Remote NDIS" (RNDIS) protocol,
  	   and Microsoft provides redistributable binary RNDIS drivers for
  	   older versions of Windows.
  
  	   If you say "y" here, the Ethernet gadget driver will try to provide
  	   a second device configuration, supporting RNDIS to talk to such
  	   Microsoft USB hosts.
  
  	   To make MS-Windows work with this, use Documentation/usb/linux.inf
  	   as the "driver info file".  For versions of MS-Windows older than
  	   XP, you'll need to download drivers from Microsoft's website; a URL
  	   is given in comments found in that info file.
  
  config USB_ETH_EEM
  	bool "Ethernet Emulation Model (EEM) support"
  	depends on USB_ETH
  	select USB_LIBCOMPOSITE
  	select USB_F_EEM
  	help
  	  CDC EEM is a newer USB standard that is somewhat simpler than CDC ECM
  	  and therefore can be supported by more hardware.  Technically ECM and
  	  EEM are designed for different applications.  The ECM model extends
  	  the network interface to the target (e.g. a USB cable modem), and the
  	  EEM model is for mobile devices to communicate with hosts using
  	  ethernet over USB.  For Linux gadgets, however, the interface with
  	  the host is the same (a usbX device), so the differences are minimal.
  
  	  If you say "y" here, the Ethernet gadget driver will use the EEM
  	  protocol rather than ECM.  If unsure, say "n".
  
  config USB_G_NCM
  	tristate "Network Control Model (NCM) support"
  	depends on NET
  	select USB_LIBCOMPOSITE
  	select USB_U_ETHER
  	select USB_F_NCM
  	select CRC32
  	help
  	  This driver implements USB CDC NCM subclass standard. NCM is
  	  an advanced protocol for Ethernet encapsulation, allows grouping
  	  of several ethernet frames into one USB transfer and different
  	  alignment possibilities.
  
  	  Say "y" to link the driver statically, or "m" to build a
  	  dynamically linked module called "g_ncm".
  
  config USB_GADGETFS
  	tristate "Gadget Filesystem"
  	help
  	  This driver provides a filesystem based API that lets user mode
  	  programs implement a single-configuration USB device, including
  	  endpoint I/O and control requests that don't relate to enumeration.
  	  All endpoints, transfer speeds, and transfer types supported by
  	  the hardware are available, through read() and write() calls.
  
  	  Say "y" to link the driver statically, or "m" to build a
  	  dynamically linked module called "gadgetfs".
  
  config USB_FUNCTIONFS
  	tristate "Function Filesystem"
  	select USB_LIBCOMPOSITE
  	select USB_F_FS
  	select USB_FUNCTIONFS_GENERIC if !(USB_FUNCTIONFS_ETH || USB_FUNCTIONFS_RNDIS)
  	help
  	  The Function Filesystem (FunctionFS) lets one create USB
  	  composite functions in user space in the same way GadgetFS
  	  lets one create USB gadgets in user space.  This allows creation
  	  of composite gadgets such that some of the functions are
  	  implemented in kernel space (for instance Ethernet, serial or
  	  mass storage) and other are implemented in user space.
  
  	  If you say "y" or "m" here you will be able what kind of
  	  configurations the gadget will provide.
  
  	  Say "y" to link the driver statically, or "m" to build
  	  a dynamically linked module called "g_ffs".
  
  config USB_FUNCTIONFS_ETH
  	bool "Include configuration with CDC ECM (Ethernet)"
  	depends on USB_FUNCTIONFS && NET
  	select USB_U_ETHER
  	select USB_F_ECM
  	select USB_F_SUBSET
  	help
  	  Include a configuration with CDC ECM function (Ethernet) and the
  	  Function Filesystem.
  
  config USB_FUNCTIONFS_RNDIS
  	bool "Include configuration with RNDIS (Ethernet)"
  	depends on USB_FUNCTIONFS && NET
  	select USB_U_ETHER
  	select USB_F_RNDIS
  	help
  	  Include a configuration with RNDIS function (Ethernet) and the Filesystem.
  
  config USB_FUNCTIONFS_GENERIC
  	bool "Include 'pure' configuration"
  	depends on USB_FUNCTIONFS
  	help
  	  Include a configuration with the Function Filesystem alone with
  	  no Ethernet interface.
  
  config USB_MASS_STORAGE
  	tristate "Mass Storage Gadget"
  	depends on BLOCK
  	select USB_LIBCOMPOSITE
  	select USB_F_MASS_STORAGE
  	help
  	  The Mass Storage Gadget acts as a USB Mass Storage disk drive.
  	  As its storage repository it can use a regular file or a block
  	  device (in much the same way as the "loop" device driver),
  	  specified as a module parameter or sysfs option.
  
  	  This driver is a replacement for now removed File-backed
  	  Storage Gadget (g_file_storage).
  
  	  Say "y" to link the driver statically, or "m" to build
  	  a dynamically linked module called "g_mass_storage".
  
  config USB_GADGET_TARGET
  	tristate "USB Gadget Target Fabric Module"
  	depends on TARGET_CORE
  	select USB_LIBCOMPOSITE
  	select USB_F_TCM
  	help
  	  This fabric is an USB gadget. Two USB protocols are supported that is
  	  BBB or BOT (Bulk Only Transport) and UAS (USB Attached SCSI). BOT is
  	  advertised on alternative interface 0 (primary) and UAS is on
  	  alternative interface 1. Both protocols can work on USB2.0 and USB3.0.
  	  UAS utilizes the USB 3.0 feature called streams support.
  
  config USB_G_SERIAL
  	tristate "Serial Gadget (with CDC ACM and CDC OBEX support)"
  	depends on TTY
  	select USB_U_SERIAL
  	select USB_F_ACM
  	select USB_F_SERIAL
  	select USB_F_OBEX
  	select USB_LIBCOMPOSITE
  	help
  	  The Serial Gadget talks to the Linux-USB generic serial driver.
  	  This driver supports a CDC-ACM module option, which can be used
  	  to interoperate with MS-Windows hosts or with the Linux-USB
  	  "cdc-acm" driver.
  
  	  This driver also supports a CDC-OBEX option.  You will need a
  	  user space OBEX server talking to /dev/ttyGS*, since the kernel
  	  itself doesn't implement the OBEX protocol.
  
  	  Say "y" to link the driver statically, or "m" to build a
  	  dynamically linked module called "g_serial".
  
  	  For more information, see Documentation/usb/gadget_serial.rst
  	  which includes instructions and a "driver info file" needed to
  	  make MS-Windows work with CDC ACM.
  
  config USB_MIDI_GADGET
  	tristate "MIDI Gadget"
  	depends on SND
  	select USB_LIBCOMPOSITE
  	select SND_RAWMIDI
  	select USB_F_MIDI
  	help
  	  The MIDI Gadget acts as a USB Audio device, with one MIDI
  	  input and one MIDI output. These MIDI jacks appear as
  	  a sound "card" in the ALSA sound system. Other MIDI
  	  connections can then be made on the gadget system, using
  	  ALSA's aconnect utility etc.
  
  	  Say "y" to link the driver statically, or "m" to build a
  	  dynamically linked module called "g_midi".
  
  config USB_G_PRINTER
  	tristate "Printer Gadget"
  	select USB_LIBCOMPOSITE
  	select USB_F_PRINTER
  	help
  	  The Printer Gadget channels data between the USB host and a
  	  userspace program driving the print engine. The user space
  	  program reads and writes the device file /dev/g_printer to
  	  receive or send printer data. It can use ioctl calls to
  	  the device file to get or set printer status.
  
  	  Say "y" to link the driver statically, or "m" to build a
  	  dynamically linked module called "g_printer".
  
  	  For more information, see Documentation/usb/gadget_printer.rst
  	  which includes sample code for accessing the device file.
  
  if TTY
  
  config USB_CDC_COMPOSITE
  	tristate "CDC Composite Device (Ethernet and ACM)"
  	depends on NET
  	select USB_LIBCOMPOSITE
  	select USB_U_SERIAL
  	select USB_U_ETHER
  	select USB_F_ACM
  	select USB_F_ECM
  	help
  	  This driver provides two functions in one configuration:
  	  a CDC Ethernet (ECM) link, and a CDC ACM (serial port) link.
  
  	  This driver requires four bulk and two interrupt endpoints,
  	  plus the ability to handle altsettings.  Not all peripheral
  	  controllers are that capable.
  
  	  Say "y" to link the driver statically, or "m" to build a
  	  dynamically linked module.
  
  config USB_G_NOKIA
  	tristate "Nokia composite gadget"
  	depends on PHONET
  	depends on BLOCK
  	select USB_LIBCOMPOSITE
  	select USB_U_SERIAL
  	select USB_U_ETHER
  	select USB_F_ACM
  	select USB_F_OBEX
  	select USB_F_PHONET
  	select USB_F_ECM
  	select USB_F_MASS_STORAGE
  	help
  	  The Nokia composite gadget provides support for acm, obex
  	  and phonet in only one composite gadget driver.
  
  	  It's only really useful for N900 hardware. If you're building
  	  a kernel for N900, say Y or M here. If unsure, say N.
  
  config USB_G_ACM_MS
  	tristate "CDC Composite Device (ACM and mass storage)"
  	depends on BLOCK
  	select USB_LIBCOMPOSITE
  	select USB_U_SERIAL
  	select USB_F_ACM
  	select USB_F_MASS_STORAGE
  	help
  	  This driver provides two functions in one configuration:
  	  a mass storage, and a CDC ACM (serial port) link.
  
  	  Say "y" to link the driver statically, or "m" to build a
  	  dynamically linked module called "g_acm_ms".
  
  config USB_G_MULTI
  	tristate "Multifunction Composite Gadget"
  	depends on BLOCK && NET
  	select USB_G_MULTI_CDC if !USB_G_MULTI_RNDIS
  	select USB_LIBCOMPOSITE
  	select USB_U_SERIAL
  	select USB_U_ETHER
  	select USB_F_ACM
  	select USB_F_MASS_STORAGE
  	help
  	  The Multifunction Composite Gadget provides Ethernet (RNDIS
  	  and/or CDC Ethernet), mass storage and ACM serial link
  	  interfaces.
  
  	  You will be asked to choose which of the two configurations is
  	  to be available in the gadget.  At least one configuration must
  	  be chosen to make the gadget usable.  Selecting more than one
  	  configuration will prevent Windows from automatically detecting
  	  the gadget as a composite gadget, so an INF file will be needed to
  	  use the gadget.
  
  	  Say "y" to link the driver statically, or "m" to build a
  	  dynamically linked module called "g_multi".
  
  config USB_G_MULTI_RNDIS
  	bool "RNDIS + CDC Serial + Storage configuration"
  	depends on USB_G_MULTI
  	select USB_F_RNDIS
  	default y
  	help
  	  This option enables a configuration with RNDIS, CDC Serial and
  	  Mass Storage functions available in the Multifunction Composite
  	  Gadget.  This is the configuration dedicated for Windows since RNDIS
  	  is Microsoft's protocol.
  
  	  If unsure, say "y".
  
  config USB_G_MULTI_CDC
  	bool "CDC Ethernet + CDC Serial + Storage configuration"
  	depends on USB_G_MULTI
  	select USB_F_ECM
  	help
  	  This option enables a configuration with CDC Ethernet (ECM), CDC
  	  Serial and Mass Storage functions available in the Multifunction
  	  Composite Gadget.
  
  	  If unsure, say "y".
  
  endif # TTY
  
  config USB_G_HID
  	tristate "HID Gadget"
  	select USB_LIBCOMPOSITE
  	select USB_F_HID
  	help
  	  The HID gadget driver provides generic emulation of USB
  	  Human Interface Devices (HID).
  
  	  For more information, see Documentation/usb/gadget_hid.rst which
  	  includes sample code for accessing the device files.
  
  	  Say "y" to link the driver statically, or "m" to build a
  	  dynamically linked module called "g_hid".
  
  # Standalone / single function gadgets
  config USB_G_DBGP
  	tristate "EHCI Debug Device Gadget"
  	depends on TTY
  	select USB_LIBCOMPOSITE
  	help
  	  This gadget emulates an EHCI Debug device. This is useful when you want
  	  to interact with an EHCI Debug Port.
  
  	  Say "y" to link the driver statically, or "m" to build a
  	  dynamically linked module called "g_dbgp".
  
  if USB_G_DBGP
  choice
  	prompt "EHCI Debug Device mode"
  	default USB_G_DBGP_SERIAL
  
  config USB_G_DBGP_PRINTK
  	depends on USB_G_DBGP
  	bool "printk"
  	help
  	  Directly printk() received data. No interaction.
  
  config USB_G_DBGP_SERIAL
  	depends on USB_G_DBGP
  	select USB_U_SERIAL
  	bool "serial"
  	help
  	  Userland can interact using /dev/ttyGSxxx.
  endchoice
  endif
  
  # put drivers that need isochronous transfer support (for audio
  # or video class gadget drivers), or specific hardware, here.
  config USB_G_WEBCAM
  	tristate "USB Webcam Gadget"
  	depends on VIDEO_V4L2
  	select USB_LIBCOMPOSITE
  	select VIDEOBUF2_VMALLOC
  	select USB_F_UVC
  	help
  	  The Webcam Gadget acts as a composite USB Audio and Video Class
  	  device. It provides a userspace API to process UVC control requests
  	  and stream video data to the host.
  
  	  Say "y" to link the driver statically, or "m" to build a
  	  dynamically linked module called "g_webcam".
  
  config USB_RAW_GADGET
  	tristate "USB Raw Gadget"
  	help
  	  USB Raw Gadget is a kernel module that provides a userspace interface
  	  for the USB Gadget subsystem. Essentially it allows to emulate USB
  	  devices from userspace. See Documentation/usb/raw-gadget.rst for
  	  details.
  
  	  Say "y" to link the driver statically, or "m" to build a
  	  dynamically linked module called "raw_gadget".
  
  endmenu
  