Realtek cr: Add autosuspend function.

[zen-stable.git] / drivers / usb / gadget / Kconfig

#
# 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).
#

menuconfig USB_GADGET
        tristate "USB Gadget Support"
        help
           USB is a master/slave protocol, organized with one master
           host (such as a PC) controlling up to 127 peripheral devices.
           The USB hardware is asymmetric, which makes it easier to set up:
           you can't connect a "to-the-host" connector to a peripheral.

           Linux can run in the host, or in the peripheral.  In both cases
           you need a low level bus controller driver, and some software
           talking to it.  Peripheral controllers are often discrete silicon,
           or are integrated with the CPU in a microcontroller.  The more
           familiar host side controllers have names like "EHCI", "OHCI",
           or "UHCI", and are usually integrated into southbridges on PC
           motherboards.

           Enable this configuration option if you want to run Linux inside
           a USB peripheral device.  Configure one hardware driver for your
           peripheral/device side bus controller, and a "gadget driver" for
           your peripheral protocol.  (If you use modular gadget drivers,
           you may configure more than one.)

           If in doubt, say "N" and don't enable these drivers; most people
           don't have this kind of hardware (except maybe inside Linux PDAs).

           For more information, see <http://www.linux-usb.org/gadget> and
           the kernel DocBook documentation for this API.

if USB_GADGET

config USB_GADGET_DEBUG
        boolean "Debugging messages (DEVELOPMENT)"
        depends on DEBUG_KERNEL
        help
           Many controller and gadget drivers will print some debugging
           messages if you use this option to ask for those messages.

           Avoid enabling these messages, even if you're actively
           debugging such a driver.  Many drivers will emit so many
           messages that the driver timings are affected, which will
           either create new failure modes or remove the one you're
           trying to track down.  Never enable these messages for a
           production build.

config USB_GADGET_DEBUG_FILES
        boolean "Debugging information files (DEVELOPMENT)"
        depends on PROC_FS
        help
           Some of the drivers in the "gadget" framework can expose
           debugging information in files such as /proc/driver/udc
           (for a peripheral controller).  The information in these
           files may help when you're troubleshooting or bringing up a
           driver on a new board.   Enable these files by choosing "Y"
           here.  If in doubt, or to conserve kernel memory, say "N".

config USB_GADGET_DEBUG_FS
        boolean "Debugging information files in debugfs (DEVELOPMENT)"
        depends on DEBUG_FS
        help
           Some of the drivers in the "gadget" framework can expose
           debugging information in files under /sys/kernel/debug/.
           The information in these files may help when you're
           troubleshooting or bringing up a driver on a new board.
           Enable these files by choosing "Y" here.  If in doubt, or
           to conserve kernel memory, say "N".

config USB_GADGET_VBUS_DRAW
        int "Maximum VBUS Power usage (2-500 mA)"
        range 2 500
        default 2
        help
           Some devices need to draw power from USB when they are
           configured, perhaps to operate circuitry or to recharge
           batteries.  This is in addition to any local power supply,
           such as an AC adapter or batteries.

           Enter the maximum power your device draws through USB, in
           milliAmperes.  The permitted range of values is 2 - 500 mA;
           0 mA would be legal, but can make some hosts misbehave.

           This value will be used except for system-specific gadget
           drivers that have more specific information.

#
# USB Peripheral Controller Support
#
# The order here is alphabetical, except that integrated controllers go
# before discrete ones so they will be the initial/default value:
#   - integrated/SOC controllers first
#   - licensed IP used in both SOC and discrete versions
#   - discrete ones (including all PCI-only controllers)
#   - debug/dummy gadget+hcd is last.
#
choice
        prompt "USB Peripheral Controller"
        depends on USB_GADGET
        help
           A USB device uses a controller to talk to its host.
           Systems should have only one such upstream link.
           Many controller drivers are platform-specific; these
           often need board-specific hooks.

#
# Integrated controllers
#

config USB_AT91
        tristate "Atmel AT91 USB Device Port"
        depends on ARCH_AT91 && !ARCH_AT91SAM9RL && !ARCH_AT91CAP9 && !ARCH_AT91SAM9G45
        help
           Many Atmel AT91 processors (such as the AT91RM2000) have a
           full speed USB Device Port with support for five configurable
           endpoints (plus endpoint zero).

           Say "y" to link the driver statically, or "m" to build a
           dynamically linked module called "at91_udc" and force all
           gadget drivers to also be dynamically linked.

config USB_ATMEL_USBA
        tristate "Atmel USBA"
        select USB_GADGET_DUALSPEED
        depends on AVR32 || ARCH_AT91CAP9 || ARCH_AT91SAM9RL || ARCH_AT91SAM9G45
        help
          USBA is the integrated high-speed USB Device controller on
          the AT32AP700x, some AT91SAM9 and AT91CAP9 processors from Atmel.

config USB_FSL_USB2
        tristate "Freescale Highspeed USB DR Peripheral Controller"
        depends on FSL_SOC || ARCH_MXC
        select USB_GADGET_DUALSPEED
        select USB_FSL_MPH_DR_OF if OF
        help
           Some of Freescale PowerPC processors have a High Speed
           Dual-Role(DR) USB controller, which supports device mode.

           The number of programmable endpoints is different through
           SOC revisions.

           Say "y" to link the driver statically, or "m" to build a
           dynamically linked module called "fsl_usb2_udc" and force
           all gadget drivers to also be dynamically linked.

config USB_FUSB300
        tristate "Faraday FUSB300 USB Peripheral Controller"
        select USB_GADGET_DUALSPEED
        help
           Faraday usb device controller FUSB300 driver

config USB_OMAP
        tristate "OMAP USB Device Controller"
        depends on ARCH_OMAP
        select ISP1301_OMAP if MACH_OMAP_H2 || MACH_OMAP_H3 || MACH_OMAP_H4_OTG
        select USB_OTG_UTILS if ARCH_OMAP
        help
           Many Texas Instruments OMAP processors have flexible full
           speed USB device controllers, with support for up to 30
           endpoints (plus endpoint zero).  This driver supports the
           controller in the OMAP 1611, and should work with controllers
           in other OMAP processors too, given minor tweaks.

           Say "y" to link the driver statically, or "m" to build a
           dynamically linked module called "omap_udc" and force all
           gadget drivers to also be dynamically linked.

config USB_PXA25X
        tristate "PXA 25x or IXP 4xx"
        depends on (ARCH_PXA && PXA25x) || ARCH_IXP4XX
        select USB_OTG_UTILS
        help
           Intel's PXA 25x series XScale ARM-5TE processors include
           an integrated full speed USB 1.1 device controller.  The
           controller in the IXP 4xx series is register-compatible.

           It has fifteen fixed-function endpoints, as well as endpoint
           zero (for control transfers).

           Say "y" to link the driver statically, or "m" to build a
           dynamically linked module called "pxa25x_udc" and force all
           gadget drivers to also be dynamically linked.

# if there's only one gadget driver, using only two bulk endpoints,
# don't waste memory for the other endpoints
config USB_PXA25X_SMALL
        depends on USB_PXA25X
        bool
        default n if USB_ETH_RNDIS
        default y if USB_ZERO
        default y if USB_ETH
        default y if USB_G_SERIAL

config USB_R8A66597
        tristate "Renesas R8A66597 USB Peripheral Controller"
        select USB_GADGET_DUALSPEED
        help
           R8A66597 is a discrete USB host and peripheral controller chip that
           supports both full and high speed USB 2.0 data transfers.
           It has nine configurable endpoints, and endpoint zero.

           Say "y" to link the driver statically, or "m" to build a
           dynamically linked module called "r8a66597_udc" and force all
           gadget drivers to also be dynamically linked.

config USB_RENESAS_USBHS
        tristate 'Renesas USBHS controller'
        depends on SUPERH || ARCH_SHMOBILE
        help
           Renesas USBHS is a discrete USB host and peripheral controller chip
           that supports both full and high speed USB 2.0 data transfers.
           It has nine or more configurable endpoints, and endpoint zero.

           Say "y" to link the driver statically, or "m" to build a
           dynamically linked module called "renesas_usbhs" and force all
           gadget drivers to also be dynamically linked.

config USB_PXA27X
        tristate "PXA 27x"
        depends on ARCH_PXA && (PXA27x || PXA3xx)
        select USB_OTG_UTILS
        help
           Intel's PXA 27x series XScale ARM v5TE processors include
           an integrated full speed USB 1.1 device controller.

           It has up to 23 endpoints, as well as endpoint zero (for
           control transfers).

           Say "y" to link the driver statically, or "m" to build a
           dynamically linked module called "pxa27x_udc" and force all
           gadget drivers to also be dynamically linked.

config USB_S3C_HSOTG
        tristate "S3C HS/OtG USB Device controller"
        depends on S3C_DEV_USB_HSOTG
        select USB_GADGET_S3C_HSOTG_PIO
        select USB_GADGET_DUALSPEED
        help
          The Samsung S3C64XX USB2.0 high-speed gadget controller
          integrated into the S3C64XX series SoC.

config USB_IMX
        tristate "Freescale IMX USB Peripheral Controller"
        depends on ARCH_MX1
        help
           Freescale's IMX series include an integrated full speed
           USB 1.1 device controller.  The controller in the IMX series
           is register-compatible.

           It has Six fixed-function endpoints, as well as endpoint
           zero (for control transfers).

           Say "y" to link the driver statically, or "m" to build a
           dynamically linked module called "imx_udc" and force all
           gadget drivers to also be dynamically linked.

config USB_S3C2410
        tristate "S3C2410 USB Device Controller"
        depends on ARCH_S3C2410
        help
          Samsung's S3C2410 is an ARM-4 processor with an integrated
          full speed USB 1.1 device controller.  It has 4 configurable
          endpoints, as well as endpoint zero (for control transfers).

          This driver has been tested on the S3C2410, S3C2412, and
          S3C2440 processors.

config USB_S3C2410_DEBUG
        boolean "S3C2410 udc debug messages"
        depends on USB_S3C2410

config USB_S3C_HSUDC
        tristate "S3C2416, S3C2443 and S3C2450 USB Device Controller"
        depends on ARCH_S3C2410
        select USB_GADGET_DUALSPEED
        help
          Samsung's S3C2416, S3C2443 and S3C2450 is an ARM9 based SoC
          integrated with dual speed USB 2.0 device controller. It has
          8 endpoints, as well as endpoint zero.

          This driver has been tested on S3C2416 and S3C2450 processors.

config USB_PXA_U2O
        tristate "PXA9xx Processor USB2.0 controller"
        depends on ARCH_MMP
        select USB_GADGET_DUALSPEED
        help
          PXA9xx Processor series include a high speed USB2.0 device
          controller, which support high speed and full speed USB peripheral.

#
# Controllers available in both integrated and discrete versions
#

# musb builds in ../musb along with host support
config USB_GADGET_MUSB_HDRC
        tristate "Inventra HDRC USB Peripheral (TI, ADI, ...)"
        depends on USB_MUSB_HDRC && (USB_MUSB_PERIPHERAL || USB_MUSB_OTG)
        select USB_GADGET_DUALSPEED
        help
          This OTG-capable silicon IP is used in dual designs including
          the TI DaVinci, OMAP 243x, OMAP 343x, TUSB 6010, and ADI Blackfin

config USB_M66592
        tristate "Renesas M66592 USB Peripheral Controller"
        select USB_GADGET_DUALSPEED
        help
           M66592 is a discrete USB peripheral controller chip that
           supports both full and high speed USB 2.0 data transfers.
           It has seven configurable endpoints, and endpoint zero.

           Say "y" to link the driver statically, or "m" to build a
           dynamically linked module called "m66592_udc" and force all
           gadget drivers to also be dynamically linked.

#
# Controllers available only in discrete form (and all PCI controllers)
#

config USB_AMD5536UDC
        tristate "AMD5536 UDC"
        depends on PCI
        select USB_GADGET_DUALSPEED
        help
           The AMD5536 UDC is part of the AMD Geode CS5536, an x86 southbridge.
           It is a USB Highspeed DMA capable USB device controller. Beside ep0
           it provides 4 IN and 4 OUT endpoints (bulk or interrupt type).
           The UDC port supports OTG operation, and may be used as a host port
           if it's not being used to implement peripheral or OTG roles.

           Say "y" to link the driver statically, or "m" to build a
           dynamically linked module called "amd5536udc" and force all
           gadget drivers to also be dynamically linked.

config USB_FSL_QE
        tristate "Freescale QE/CPM USB Device Controller"
        depends on FSL_SOC && (QUICC_ENGINE || CPM)
        help
           Some of Freescale PowerPC processors have a Full Speed
           QE/CPM2 USB controller, which support device mode with 4
           programmable endpoints. This driver supports the
           controller in the MPC8360 and MPC8272, and should work with
           controllers having QE or CPM2, given minor tweaks.

           Set CONFIG_USB_GADGET to "m" to build this driver as a
           dynamically linked module called "fsl_qe_udc".

config USB_CI13XXX_PCI
        tristate "MIPS USB CI13xxx PCI UDC"
        depends on PCI
        select USB_GADGET_DUALSPEED
        help
          MIPS USB IP core family device controller
          Currently it only supports IP part number CI13412

          Say "y" to link the driver statically, or "m" to build a
          dynamically linked module called "ci13xxx_udc" and force all
          gadget drivers to also be dynamically linked.

config USB_NET2272
        tristate "PLX NET2272"
        select USB_GADGET_DUALSPEED
        help
          PLX NET2272 is a USB peripheral controller which supports
          both full and high speed USB 2.0 data transfers.

          It has three configurable endpoints, as well as endpoint zero
          (for control transfer).
          Say "y" to link the driver statically, or "m" to build a
          dynamically linked module called "net2272" and force all
          gadget drivers to also be dynamically linked.

config USB_NET2272_DMA
        boolean "Support external DMA controller"
        depends on USB_NET2272
        help
          The NET2272 part can optionally support an external DMA
          controller, but your board has to have support in the
          driver itself.

          If unsure, say "N" here.  The driver works fine in PIO mode.

config USB_NET2280
        tristate "NetChip 228x"
        depends on PCI
        select USB_GADGET_DUALSPEED
        help
           NetChip 2280 / 2282 is a PCI based USB peripheral controller which
           supports both full and high speed USB 2.0 data transfers.

           It has six configurable endpoints, as well as endpoint zero
           (for control transfers) and several endpoints with dedicated
           functions.

           Say "y" to link the driver statically, or "m" to build a
           dynamically linked module called "net2280" and force all
           gadget drivers to also be dynamically linked.

config USB_GOKU
        tristate "Toshiba TC86C001 'Goku-S'"
        depends on PCI
        help
           The Toshiba TC86C001 is a PCI device which includes controllers
           for full speed USB devices, IDE, I2C, SIO, plus a USB host (OHCI).

           The device controller has three configurable (bulk or interrupt)
           endpoints, plus endpoint zero (for control transfers).

           Say "y" to link the driver statically, or "m" to build a
           dynamically linked module called "goku_udc" and to force all
           gadget drivers to also be dynamically linked.

config USB_LANGWELL
        tristate "Intel Langwell USB Device Controller"
        depends on PCI
        select USB_GADGET_DUALSPEED
        help
           Intel Langwell USB Device Controller is a High-Speed USB
           On-The-Go device controller.

           The number of programmable endpoints is different through
           controller revision.

           Say "y" to link the driver statically, or "m" to build a
           dynamically linked module called "langwell_udc" and force all
           gadget drivers to also be dynamically linked.

config USB_EG20T
        tristate "Intel EG20T PCH/OKI SEMICONDUCTOR ML7213 IOH UDC"
        depends on PCI
        select USB_GADGET_DUALSPEED
        help
          This is a USB device driver for EG20T PCH.
          EG20T PCH is the platform controller hub that is used in Intel's
          general embedded platform. EG20T PCH has USB device interface.
          Using this interface, it is able to access system devices connected
          to USB device.
          This driver enables USB device function.
          USB device is a USB peripheral controller which
          supports both full and high speed USB 2.0 data transfers.
          This driver supports both control transfer and bulk transfer modes.
          This driver dose not support interrupt transfer or isochronous
          transfer modes.

          This driver also can be used for OKI SEMICONDUCTOR's ML7213 which is
          for IVI(In-Vehicle Infotainment) use.
          ML7213 is companion chip for Intel Atom E6xx series.
          ML7213 is completely compatible for Intel EG20T PCH.

config USB_CI13XXX_MSM
        tristate "MIPS USB CI13xxx for MSM"
        depends on ARCH_MSM
        select USB_GADGET_DUALSPEED
        select USB_MSM_OTG
        help
          MSM SoC has chipidea USB controller.  This driver uses
          ci13xxx_udc core.
          This driver depends on OTG driver for PHY initialization,
          clock management, powering up VBUS, and power management.
          This driver is not supported on boards like trout which
          has an external PHY.

          Say "y" to link the driver statically, or "m" to build a
          dynamically linked module called "ci13xxx_msm" and force all
          gadget drivers to also be dynamically linked.

#
# LAST -- dummy/emulated controller
#

config USB_DUMMY_HCD
        tristate "Dummy HCD (DEVELOPMENT)"
        depends on USB=y || (USB=m && USB_GADGET=m)
        select USB_GADGET_DUALSPEED
        select USB_GADGET_SUPERSPEED
        help
          This host controller driver emulates USB, looping all data transfer
          requests back to a USB "gadget driver" in the same host.  The host
          side is the master; the gadget side is the slave.  Gadget drivers
          can be high, full, or low speed; and they have access to endpoints
          like those from NET2280, PXA2xx, or SA1100 hardware.

          This may help in some stages of creating a driver to embed in a
          Linux device, since it lets you debug several parts of the gadget
          driver without its hardware or drivers being involved.

          Since such a gadget side driver needs to interoperate with a host
          side Linux-USB device driver, this may help to debug both sides
          of a USB protocol stack.

          Say "y" to link the driver statically, or "m" to build a
          dynamically linked module called "dummy_hcd" and force all
          gadget drivers to also be dynamically linked.

# NOTE:  Please keep dummy_hcd LAST so that "real hardware" appears
# first and will be selected by default.

endchoice

# Selected by UDC drivers that support high-speed operation.
config USB_GADGET_DUALSPEED
        bool
        depends on USB_GADGET

# Selected by UDC drivers that support super-speed opperation
config USB_GADGET_SUPERSPEED
        bool
        depends on USB_GADGET
        depends on USB_GADGET_DUALSPEED

#
# USB Gadget Drivers
#
choice
        tristate "USB Gadget Drivers"
        depends on USB_GADGET
        default USB_ETH
        help
          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.

# this first set of drivers all depend on bulk-capable hardware.

config USB_ZERO
        tristate "Gadget Zero (DEVELOPMENT)"
        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
        boolean "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 (EXPERIMENTAL)"
        depends on SND
        select SND_PCM
        help
          Gadget Audio is compatible with USB Audio Class specification 1.0.
          It will include at least one AudioControl interface, zero or more
          AudioStream interface and zero or more MIDIStream interface.

          Gadget Audio will use on-board ALSA (CONFIG_SND) audio card to
          playback or capture audio stream.

          Say "y" to link the driver statically, or "m" to build a
          dynamically linked module called "g_audio".

config USB_ETH
        tristate "Ethernet Gadget (with CDC Ethernet support)"
        depends on NET
        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 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
        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
       default n
       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 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 diffferent
          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 (EXPERIMENTAL)"
        depends on EXPERIMENTAL
        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.

          Currently, this option is still labelled as EXPERIMENTAL because
          of existing race conditions in the underlying in-kernel AIO core.

          Say "y" to link the driver statically, or "m" to build a
          dynamically linked module called "gadgetfs".

config USB_FUNCTIONFS
        tristate "Function Filesystem (EXPERIMENTAL)"
        depends on EXPERIMENTAL
        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
        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
        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_FILE_STORAGE
        tristate "File-backed Storage Gadget (DEPRECATED)"
        depends on BLOCK
        help
          The File-backed 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.

          Say "y" to link the driver statically, or "m" to build a
          dynamically linked module called "g_file_storage".

          NOTE: This driver is deprecated.  Its replacement is the
          Mass Storage Gadget.

config USB_FILE_STORAGE_TEST
        bool "File-backed Storage Gadget testing version"
        depends on USB_FILE_STORAGE
        default n
        help
          Say "y" to generate the larger testing version of the
          File-backed Storage Gadget, useful for probing the
          behavior of USB Mass Storage hosts.  Not needed for
          normal operation.

config USB_MASS_STORAGE
        tristate "Mass Storage Gadget"
        depends on BLOCK
        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 an updated replacement for the deprecated
          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_G_SERIAL
        tristate "Serial Gadget (with CDC ACM and CDC OBEX support)"
        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.txt
          which includes instructions and a "driver info file" needed to
          make MS-Windows work with CDC ACM.

config USB_MIDI_GADGET
        tristate "MIDI Gadget (EXPERIMENTAL)"
        depends on SND && EXPERIMENTAL
        select SND_RAWMIDI
        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"
        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.txt
          which includes sample code for accessing the device file.

config USB_CDC_COMPOSITE
        tristate "CDC Composite Device (Ethernet and ACM)"
        depends on NET
        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
        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_MULTI
        tristate "Multifunction Composite Gadget (EXPERIMENTAL)"
        depends on BLOCK && NET
        select USB_G_MULTI_CDC if !USB_G_MULTI_RNDIS
        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
        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
        default n
        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".

config USB_G_HID
        tristate "HID Gadget"
        help
          The HID gadget driver provides generic emulation of USB
          Human Interface Devices (HID).

          For more information, see Documentation/usb/gadget_hid.txt 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".

config USB_G_DBGP
        tristate "EHCI Debug Device Gadget"
        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
        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_DEV
        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".

endchoice

endif # USB_GADGET