0001 # SPDX-License-Identifier: GPL-2.0
0002 #
0003 # USB Gadget support on a system involves
0004 # (a) a peripheral controller, and
0005 # (b) the gadget driver using it.
0006 #
0007 # NOTE: Gadget support ** DOES NOT ** depend on host-side CONFIG_USB !!
0008 #
0009 # - Host systems (like PCs) need CONFIG_USB (with "A" jacks).
0010 # - Peripherals (like PDAs) need CONFIG_USB_GADGET (with "B" jacks).
0011 # - Some systems have both kinds of controllers.
0012 #
0013 # With help from a special transceiver and a "Mini-AB" jack, systems with
0014 # both kinds of controller can also support "USB On-the-Go" (CONFIG_USB_OTG).
0015 #
0016
0017 menuconfig USB_GADGET
0018 tristate "USB Gadget Support"
0019 select USB_COMMON
0020 select NLS
0021 help
0022 USB is a host/device protocol, organized with one host (such as a
0023 PC) controlling up to 127 peripheral devices.
0024 The USB hardware is asymmetric, which makes it easier to set up:
0025 you can't connect a "to-the-host" connector to a peripheral.
0026
0027 Linux can run in the host, or in the peripheral. In both cases
0028 you need a low level bus controller driver, and some software
0029 talking to it. Peripheral controllers are often discrete silicon,
0030 or are integrated with the CPU in a microcontroller. The more
0031 familiar host side controllers have names like "EHCI", "OHCI",
0032 or "UHCI", and are usually integrated into southbridges on PC
0033 motherboards.
0034
0035 Enable this configuration option if you want to run Linux inside
0036 a USB peripheral device. Configure one hardware driver for your
0037 peripheral/device side bus controller, and a "gadget driver" for
0038 your peripheral protocol. (If you use modular gadget drivers,
0039 you may configure more than one.)
0040
0041 If in doubt, say "N" and don't enable these drivers; most people
0042 don't have this kind of hardware (except maybe inside Linux PDAs).
0043
0044 For more information, see <http://www.linux-usb.org/gadget> and
0045 the kernel documentation for this API.
0046
0047 if USB_GADGET
0048
0049 config USB_GADGET_DEBUG
0050 bool "Debugging messages (DEVELOPMENT)"
0051 depends on DEBUG_KERNEL
0052 help
0053 Many controller and gadget drivers will print some debugging
0054 messages if you use this option to ask for those messages.
0055
0056 Avoid enabling these messages, even if you're actively
0057 debugging such a driver. Many drivers will emit so many
0058 messages that the driver timings are affected, which will
0059 either create new failure modes or remove the one you're
0060 trying to track down. Never enable these messages for a
0061 production build.
0062
0063 config USB_GADGET_VERBOSE
0064 bool "Verbose debugging Messages (DEVELOPMENT)"
0065 depends on USB_GADGET_DEBUG
0066 help
0067 Many controller and gadget drivers will print verbose debugging
0068 messages if you use this option to ask for those messages.
0069
0070 Avoid enabling these messages, even if you're actively
0071 debugging such a driver. Many drivers will emit so many
0072 messages that the driver timings are affected, which will
0073 either create new failure modes or remove the one you're
0074 trying to track down. Never enable these messages for a
0075 production build.
0076
0077 config USB_GADGET_DEBUG_FILES
0078 bool "Debugging information files (DEVELOPMENT)"
0079 depends on PROC_FS
0080 help
0081 Some of the drivers in the "gadget" framework can expose
0082 debugging information in files such as /proc/driver/udc
0083 (for a peripheral controller). The information in these
0084 files may help when you're troubleshooting or bringing up a
0085 driver on a new board. Enable these files by choosing "Y"
0086 here. If in doubt, or to conserve kernel memory, say "N".
0087
0088 config USB_GADGET_DEBUG_FS
0089 bool "Debugging information files in debugfs (DEVELOPMENT)"
0090 depends on DEBUG_FS
0091 help
0092 Some of the drivers in the "gadget" framework can expose
0093 debugging information in files under /sys/kernel/debug/.
0094 The information in these files may help when you're
0095 troubleshooting or bringing up a driver on a new board.
0096 Enable these files by choosing "Y" here. If in doubt, or
0097 to conserve kernel memory, say "N".
0098
0099 config USB_GADGET_VBUS_DRAW
0100 int "Maximum VBUS Power usage (2-500 mA)"
0101 range 2 500
0102 default 2
0103 help
0104 Some devices need to draw power from USB when they are
0105 configured, perhaps to operate circuitry or to recharge
0106 batteries. This is in addition to any local power supply,
0107 such as an AC adapter or batteries.
0108
0109 Enter the maximum power your device draws through USB, in
0110 milliAmperes. The permitted range of values is 2 - 500 mA;
0111 0 mA would be legal, but can make some hosts misbehave.
0112
0113 This value will be used except for system-specific gadget
0114 drivers that have more specific information.
0115
0116 config USB_GADGET_STORAGE_NUM_BUFFERS
0117 int "Number of storage pipeline buffers"
0118 range 2 256
0119 default 2
0120 help
0121 Usually 2 buffers are enough to establish a good buffering
0122 pipeline. The number may be increased in order to compensate
0123 for a bursty VFS behaviour. For instance there may be CPU wake up
0124 latencies that makes the VFS to appear bursty in a system with
0125 an CPU on-demand governor. Especially if DMA is doing IO to
0126 offload the CPU. In this case the CPU will go into power
0127 save often and spin up occasionally to move data within VFS.
0128 If selecting USB_GADGET_DEBUG_FILES this value may be set by
0129 a module parameter as well.
0130 If unsure, say 2.
0131
0132 config U_SERIAL_CONSOLE
0133 bool "Serial gadget console support"
0134 depends on USB_U_SERIAL
0135 help
0136 It supports the serial gadget can be used as a console.
0137
0138 source "drivers/usb/gadget/udc/Kconfig"
0139
0140 #
0141 # USB Gadget Drivers
0142 #
0143
0144 # composite based drivers
0145 config USB_LIBCOMPOSITE
0146 tristate
0147 select CONFIGFS_FS
0148 depends on USB_GADGET
0149
0150 config USB_F_ACM
0151 tristate
0152
0153 config USB_F_SS_LB
0154 tristate
0155
0156 config USB_U_SERIAL
0157 tristate
0158
0159 config USB_U_ETHER
0160 tristate
0161
0162 config USB_U_AUDIO
0163 tristate
0164
0165 config USB_F_SERIAL
0166 tristate
0167
0168 config USB_F_OBEX
0169 tristate
0170
0171 config USB_F_NCM
0172 tristate
0173
0174 config USB_F_ECM
0175 tristate
0176
0177 config USB_F_PHONET
0178 tristate
0179
0180 config USB_F_EEM
0181 tristate
0182
0183 config USB_F_SUBSET
0184 tristate
0185
0186 config USB_F_RNDIS
0187 tristate
0188
0189 config USB_F_MASS_STORAGE
0190 tristate
0191
0192 config USB_F_FS
0193 tristate
0194
0195 config USB_F_UAC1
0196 tristate
0197
0198 config USB_F_UAC1_LEGACY
0199 tristate
0200
0201 config USB_F_UAC2
0202 tristate
0203
0204 config USB_F_UVC
0205 tristate
0206
0207 config USB_F_MIDI
0208 tristate
0209
0210 config USB_F_HID
0211 tristate
0212
0213 config USB_F_PRINTER
0214 tristate
0215
0216 config USB_F_TCM
0217 tristate
0218
0219 # this first set of drivers all depend on bulk-capable hardware.
0220
0221 config USB_CONFIGFS
0222 tristate "USB Gadget functions configurable through configfs"
0223 select USB_LIBCOMPOSITE
0224 help
0225 A Linux USB "gadget" can be set up through configfs.
0226 If this is the case, the USB functions (which from the host's
0227 perspective are seen as interfaces) and configurations are
0228 specified simply by creating appropriate directories in configfs.
0229 Associating functions with configurations is done by creating
0230 appropriate symbolic links.
0231 For more information see Documentation/usb/gadget_configfs.rst.
0232
0233 config USB_CONFIGFS_SERIAL
0234 bool "Generic serial bulk in/out"
0235 depends on USB_CONFIGFS
0236 depends on TTY
0237 select USB_U_SERIAL
0238 select USB_F_SERIAL
0239 help
0240 The function talks to the Linux-USB generic serial driver.
0241
0242 config USB_CONFIGFS_ACM
0243 bool "Abstract Control Model (CDC ACM)"
0244 depends on USB_CONFIGFS
0245 depends on TTY
0246 select USB_U_SERIAL
0247 select USB_F_ACM
0248 help
0249 ACM serial link. This function can be used to interoperate with
0250 MS-Windows hosts or with the Linux-USB "cdc-acm" driver.
0251
0252 config USB_CONFIGFS_OBEX
0253 bool "Object Exchange Model (CDC OBEX)"
0254 depends on USB_CONFIGFS
0255 depends on TTY
0256 select USB_U_SERIAL
0257 select USB_F_OBEX
0258 help
0259 You will need a user space OBEX server talking to /dev/ttyGS*,
0260 since the kernel itself doesn't implement the OBEX protocol.
0261
0262 config USB_CONFIGFS_NCM
0263 bool "Network Control Model (CDC NCM)"
0264 depends on USB_CONFIGFS
0265 depends on NET
0266 select USB_U_ETHER
0267 select USB_F_NCM
0268 select CRC32
0269 help
0270 NCM is an advanced protocol for Ethernet encapsulation, allows
0271 grouping of several ethernet frames into one USB transfer and
0272 different alignment possibilities.
0273
0274 config USB_CONFIGFS_ECM
0275 bool "Ethernet Control Model (CDC ECM)"
0276 depends on USB_CONFIGFS
0277 depends on NET
0278 select USB_U_ETHER
0279 select USB_F_ECM
0280 help
0281 The "Communication Device Class" (CDC) Ethernet Control Model.
0282 That protocol is often avoided with pure Ethernet adapters, in
0283 favor of simpler vendor-specific hardware, but is widely
0284 supported by firmware for smart network devices.
0285
0286 config USB_CONFIGFS_ECM_SUBSET
0287 bool "Ethernet Control Model (CDC ECM) subset"
0288 depends on USB_CONFIGFS
0289 depends on NET
0290 select USB_U_ETHER
0291 select USB_F_SUBSET
0292 help
0293 On hardware that can't implement the full protocol,
0294 a simple CDC subset is used, placing fewer demands on USB.
0295
0296 config USB_CONFIGFS_RNDIS
0297 bool "RNDIS"
0298 depends on USB_CONFIGFS
0299 depends on NET
0300 select USB_U_ETHER
0301 select USB_F_RNDIS
0302 help
0303 Microsoft Windows XP bundles the "Remote NDIS" (RNDIS) protocol,
0304 and Microsoft provides redistributable binary RNDIS drivers for
0305 older versions of Windows.
0306
0307 To make MS-Windows work with this, use Documentation/usb/linux.inf
0308 as the "driver info file". For versions of MS-Windows older than
0309 XP, you'll need to download drivers from Microsoft's website; a URL
0310 is given in comments found in that info file.
0311
0312 config USB_CONFIGFS_EEM
0313 bool "Ethernet Emulation Model (EEM)"
0314 depends on USB_CONFIGFS
0315 depends on NET
0316 select USB_U_ETHER
0317 select USB_F_EEM
0318 select CRC32
0319 help
0320 CDC EEM is a newer USB standard that is somewhat simpler than CDC ECM
0321 and therefore can be supported by more hardware. Technically ECM and
0322 EEM are designed for different applications. The ECM model extends
0323 the network interface to the target (e.g. a USB cable modem), and the
0324 EEM model is for mobile devices to communicate with hosts using
0325 ethernet over USB. For Linux gadgets, however, the interface with
0326 the host is the same (a usbX device), so the differences are minimal.
0327
0328 config USB_CONFIGFS_PHONET
0329 bool "Phonet protocol"
0330 depends on USB_CONFIGFS
0331 depends on NET
0332 depends on PHONET
0333 select USB_U_ETHER
0334 select USB_F_PHONET
0335 help
0336 The Phonet protocol implementation for USB device.
0337
0338 config USB_CONFIGFS_MASS_STORAGE
0339 bool "Mass storage"
0340 depends on USB_CONFIGFS
0341 depends on BLOCK
0342 select USB_F_MASS_STORAGE
0343 help
0344 The Mass Storage Gadget acts as a USB Mass Storage disk drive.
0345 As its storage repository it can use a regular file or a block
0346 device (in much the same way as the "loop" device driver),
0347 specified as a module parameter or sysfs option.
0348
0349 config USB_CONFIGFS_F_LB_SS
0350 bool "Loopback and sourcesink function (for testing)"
0351 depends on USB_CONFIGFS
0352 select USB_F_SS_LB
0353 help
0354 Loopback function loops back a configurable number of transfers.
0355 Sourcesink function either sinks and sources bulk data.
0356 It also implements control requests, for "chapter 9" conformance.
0357 Make this be the first driver you try using on top of any new
0358 USB peripheral controller driver. Then you can use host-side
0359 test software, like the "usbtest" driver, to put your hardware
0360 and its driver through a basic set of functional tests.
0361
0362 config USB_CONFIGFS_F_FS
0363 bool "Function filesystem (FunctionFS)"
0364 depends on USB_CONFIGFS
0365 select USB_F_FS
0366 help
0367 The Function Filesystem (FunctionFS) lets one create USB
0368 composite functions in user space in the same way GadgetFS
0369 lets one create USB gadgets in user space. This allows creation
0370 of composite gadgets such that some of the functions are
0371 implemented in kernel space (for instance Ethernet, serial or
0372 mass storage) and other are implemented in user space.
0373
0374 config USB_CONFIGFS_F_UAC1
0375 bool "Audio Class 1.0"
0376 depends on USB_CONFIGFS
0377 depends on SND
0378 select USB_LIBCOMPOSITE
0379 select SND_PCM
0380 select USB_U_AUDIO
0381 select USB_F_UAC1
0382 help
0383 This Audio function implements 1 AudioControl interface,
0384 1 AudioStreaming Interface each for USB-OUT and USB-IN.
0385 This driver doesn't expect any real Audio codec to be present
0386 on the device - the audio streams are simply sinked to and
0387 sourced from a virtual ALSA sound card created. The user-space
0388 application may choose to do whatever it wants with the data
0389 received from the USB Host and choose to provide whatever it
0390 wants as audio data to the USB Host.
0391
0392 config USB_CONFIGFS_F_UAC1_LEGACY
0393 bool "Audio Class 1.0 (legacy implementation)"
0394 depends on USB_CONFIGFS
0395 depends on SND
0396 select USB_LIBCOMPOSITE
0397 select SND_PCM
0398 select USB_F_UAC1_LEGACY
0399 help
0400 This Audio function implements 1 AudioControl interface,
0401 1 AudioStreaming Interface each for USB-OUT and USB-IN.
0402 This is a legacy driver and requires a real Audio codec
0403 to be present on the device.
0404
0405 config USB_CONFIGFS_F_UAC2
0406 bool "Audio Class 2.0"
0407 depends on USB_CONFIGFS
0408 depends on SND
0409 select USB_LIBCOMPOSITE
0410 select SND_PCM
0411 select USB_U_AUDIO
0412 select USB_F_UAC2
0413 help
0414 This Audio function is compatible with USB Audio Class
0415 specification 2.0. It implements 1 AudioControl interface,
0416 1 AudioStreaming Interface each for USB-OUT and USB-IN.
0417 This driver doesn't expect any real Audio codec to be present
0418 on the device - the audio streams are simply sinked to and
0419 sourced from a virtual ALSA sound card created. The user-space
0420 application may choose to do whatever it wants with the data
0421 received from the USB Host and choose to provide whatever it
0422 wants as audio data to the USB Host.
0423
0424 config USB_CONFIGFS_F_MIDI
0425 bool "MIDI function"
0426 depends on USB_CONFIGFS
0427 depends on SND
0428 select USB_LIBCOMPOSITE
0429 select SND_RAWMIDI
0430 select USB_F_MIDI
0431 help
0432 The MIDI Function acts as a USB Audio device, with one MIDI
0433 input and one MIDI output. These MIDI jacks appear as
0434 a sound "card" in the ALSA sound system. Other MIDI
0435 connections can then be made on the gadget system, using
0436 ALSA's aconnect utility etc.
0437
0438 config USB_CONFIGFS_F_HID
0439 bool "HID function"
0440 depends on USB_CONFIGFS
0441 select USB_F_HID
0442 help
0443 The HID function driver provides generic emulation of USB
0444 Human Interface Devices (HID).
0445
0446 For more information, see Documentation/usb/gadget_hid.rst.
0447
0448 config USB_CONFIGFS_F_UVC
0449 bool "USB Webcam function"
0450 depends on USB_CONFIGFS
0451 depends on VIDEO_DEV
0452 depends on VIDEO_DEV
0453 select VIDEOBUF2_DMA_SG
0454 select VIDEOBUF2_VMALLOC
0455 select USB_F_UVC
0456 help
0457 The Webcam function acts as a composite USB Audio and Video Class
0458 device. It provides a userspace API to process UVC control requests
0459 and stream video data to the host.
0460
0461 config USB_CONFIGFS_F_PRINTER
0462 bool "Printer function"
0463 select USB_F_PRINTER
0464 depends on USB_CONFIGFS
0465 help
0466 The Printer function channels data between the USB host and a
0467 userspace program driving the print engine. The user space
0468 program reads and writes the device file /dev/g_printer<X> to
0469 receive or send printer data. It can use ioctl calls to
0470 the device file to get or set printer status.
0471
0472 For more information, see Documentation/usb/gadget_printer.rst
0473 which includes sample code for accessing the device file.
0474
0475 config USB_CONFIGFS_F_TCM
0476 bool "USB Gadget Target Fabric"
0477 depends on TARGET_CORE
0478 depends on USB_CONFIGFS
0479 select USB_LIBCOMPOSITE
0480 select USB_F_TCM
0481 help
0482 This fabric is a USB gadget component. Two USB protocols are
0483 supported that is BBB or BOT (Bulk Only Transport) and UAS
0484 (USB Attached SCSI). BOT is advertised on alternative
0485 interface 0 (primary) and UAS is on alternative interface 1.
0486 Both protocols can work on USB2.0 and USB3.0.
0487 UAS utilizes the USB 3.0 feature called streams support.
0488
0489 source "drivers/usb/gadget/legacy/Kconfig"
0490
0491 endif # USB_GADGET
