# # 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). # choice tristate "USB Gadget precomposed configurations" default USB_ETH optional 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. 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. 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 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 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.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" 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.txt 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 default n 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.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". # 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". endchoice