1# SPDX-License-Identifier: GPL-2.0 2# 3# USB Gadget support on a system involves 4# (a) a peripheral controller, and 5# (b) the gadget driver using it. 6# 7# NOTE: Gadget support ** DOES NOT ** depend on host-side CONFIG_USB !! 8# 9# - Host systems (like PCs) need CONFIG_USB (with "A" jacks). 10# - Peripherals (like PDAs) need CONFIG_USB_GADGET (with "B" jacks). 11# - Some systems have both kinds of controllers. 12# 13# With help from a special transceiver and a "Mini-AB" jack, systems with 14# both kinds of controller can also support "USB On-the-Go" (CONFIG_USB_OTG). 15# 16 17menuconfig USB_GADGET 18 tristate "USB Gadget Support" 19 select USB_COMMON 20 select NLS 21 help 22 USB is a host/device protocol, organized with one host (such as a 23 PC) controlling up to 127 peripheral devices. 24 The USB hardware is asymmetric, which makes it easier to set up: 25 you can't connect a "to-the-host" connector to a peripheral. 26 27 Linux can run in the host, or in the peripheral. In both cases 28 you need a low level bus controller driver, and some software 29 talking to it. Peripheral controllers are often discrete silicon, 30 or are integrated with the CPU in a microcontroller. The more 31 familiar host side controllers have names like "EHCI", "OHCI", 32 or "UHCI", and are usually integrated into southbridges on PC 33 motherboards. 34 35 Enable this configuration option if you want to run Linux inside 36 a USB peripheral device. Configure one hardware driver for your 37 peripheral/device side bus controller, and a "gadget driver" for 38 your peripheral protocol. (If you use modular gadget drivers, 39 you may configure more than one.) 40 41 If in doubt, say "N" and don't enable these drivers; most people 42 don't have this kind of hardware (except maybe inside Linux PDAs). 43 44 For more information, see <http://www.linux-usb.org/gadget> and 45 the kernel documentation for this API. 46 47if USB_GADGET 48 49config USB_GADGET_DEBUG 50 bool "Debugging messages (DEVELOPMENT)" 51 depends on DEBUG_KERNEL 52 help 53 Many controller and gadget drivers will print some debugging 54 messages if you use this option to ask for those messages. 55 56 Avoid enabling these messages, even if you're actively 57 debugging such a driver. Many drivers will emit so many 58 messages that the driver timings are affected, which will 59 either create new failure modes or remove the one you're 60 trying to track down. Never enable these messages for a 61 production build. 62 63config USB_GADGET_VERBOSE 64 bool "Verbose debugging Messages (DEVELOPMENT)" 65 depends on USB_GADGET_DEBUG 66 help 67 Many controller and gadget drivers will print verbose debugging 68 messages if you use this option to ask for those messages. 69 70 Avoid enabling these messages, even if you're actively 71 debugging such a driver. Many drivers will emit so many 72 messages that the driver timings are affected, which will 73 either create new failure modes or remove the one you're 74 trying to track down. Never enable these messages for a 75 production build. 76 77config USB_GADGET_DEBUG_FILES 78 bool "Debugging information files (DEVELOPMENT)" 79 depends on PROC_FS 80 help 81 Some of the drivers in the "gadget" framework can expose 82 debugging information in files such as /proc/driver/udc 83 (for a peripheral controller). The information in these 84 files may help when you're troubleshooting or bringing up a 85 driver on a new board. Enable these files by choosing "Y" 86 here. If in doubt, or to conserve kernel memory, say "N". 87 88config USB_GADGET_DEBUG_FS 89 bool "Debugging information files in debugfs (DEVELOPMENT)" 90 depends on DEBUG_FS 91 help 92 Some of the drivers in the "gadget" framework can expose 93 debugging information in files under /sys/kernel/debug/. 94 The information in these files may help when you're 95 troubleshooting or bringing up a driver on a new board. 96 Enable these files by choosing "Y" here. If in doubt, or 97 to conserve kernel memory, say "N". 98 99config USB_GADGET_VBUS_DRAW 100 int "Maximum VBUS Power usage (2-500 mA)" 101 range 2 500 102 default 2 103 help 104 Some devices need to draw power from USB when they are 105 configured, perhaps to operate circuitry or to recharge 106 batteries. This is in addition to any local power supply, 107 such as an AC adapter or batteries. 108 109 Enter the maximum power your device draws through USB, in 110 milliAmperes. The permitted range of values is 2 - 500 mA; 111 0 mA would be legal, but can make some hosts misbehave. 112 113 This value will be used except for system-specific gadget 114 drivers that have more specific information. 115 116config USB_GADGET_STORAGE_NUM_BUFFERS 117 int "Number of storage pipeline buffers" 118 range 2 256 119 default 2 120 help 121 Usually 2 buffers are enough to establish a good buffering 122 pipeline. The number may be increased in order to compensate 123 for a bursty VFS behaviour. For instance there may be CPU wake up 124 latencies that makes the VFS to appear bursty in a system with 125 an CPU on-demand governor. Especially if DMA is doing IO to 126 offload the CPU. In this case the CPU will go into power 127 save often and spin up occasionally to move data within VFS. 128 If selecting USB_GADGET_DEBUG_FILES this value may be set by 129 a module parameter as well. 130 If unsure, say 2. 131 132config U_SERIAL_CONSOLE 133 bool "Serial gadget console support" 134 depends on USB_U_SERIAL 135 help 136 It supports the serial gadget can be used as a console. 137 138source "drivers/usb/gadget/udc/Kconfig" 139 140# 141# USB Gadget Drivers 142# 143 144# composite based drivers 145config USB_LIBCOMPOSITE 146 tristate 147 select CONFIGFS_FS 148 depends on USB_GADGET 149 150config USB_F_ACM 151 tristate 152 153config USB_F_SS_LB 154 tristate 155 156config USB_U_SERIAL 157 tristate 158 159config USB_U_ETHER 160 tristate 161 162config USB_U_AUDIO 163 tristate 164 165config USB_F_SERIAL 166 tristate 167 168config USB_F_OBEX 169 tristate 170 171config USB_F_NCM 172 tristate 173 174config USB_F_ECM 175 tristate 176 177config USB_F_PHONET 178 tristate 179 180config USB_F_EEM 181 tristate 182 183config USB_F_SUBSET 184 tristate 185 186config USB_F_RNDIS 187 tristate 188 189config USB_F_MASS_STORAGE 190 tristate 191 192config USB_F_FS 193 tristate 194 195config USB_F_UAC1 196 tristate 197 198config USB_F_UAC1_LEGACY 199 tristate 200 201config USB_F_UAC2 202 tristate 203 204config USB_F_UVC 205 tristate 206 207config USB_F_MIDI 208 tristate 209 210config USB_F_HID 211 tristate 212 213config USB_F_PRINTER 214 tristate 215 216config USB_F_TCM 217 tristate 218 219# this first set of drivers all depend on bulk-capable hardware. 220 221config USB_CONFIGFS 222 tristate "USB Gadget functions configurable through configfs" 223 select USB_LIBCOMPOSITE 224 help 225 A Linux USB "gadget" can be set up through configfs. 226 If this is the case, the USB functions (which from the host's 227 perspective are seen as interfaces) and configurations are 228 specified simply by creating appropriate directories in configfs. 229 Associating functions with configurations is done by creating 230 appropriate symbolic links. 231 For more information see Documentation/usb/gadget_configfs.rst. 232 233config USB_CONFIGFS_SERIAL 234 bool "Generic serial bulk in/out" 235 depends on USB_CONFIGFS 236 depends on TTY 237 select USB_U_SERIAL 238 select USB_F_SERIAL 239 help 240 The function talks to the Linux-USB generic serial driver. 241 242config USB_CONFIGFS_ACM 243 bool "Abstract Control Model (CDC ACM)" 244 depends on USB_CONFIGFS 245 depends on TTY 246 select USB_U_SERIAL 247 select USB_F_ACM 248 help 249 ACM serial link. This function can be used to interoperate with 250 MS-Windows hosts or with the Linux-USB "cdc-acm" driver. 251 252config USB_CONFIGFS_OBEX 253 bool "Object Exchange Model (CDC OBEX)" 254 depends on USB_CONFIGFS 255 depends on TTY 256 select USB_U_SERIAL 257 select USB_F_OBEX 258 help 259 You will need a user space OBEX server talking to /dev/ttyGS*, 260 since the kernel itself doesn't implement the OBEX protocol. 261 262config USB_CONFIGFS_NCM 263 bool "Network Control Model (CDC NCM)" 264 depends on USB_CONFIGFS 265 depends on NET 266 select USB_U_ETHER 267 select USB_F_NCM 268 select CRC32 269 help 270 NCM is an advanced protocol for Ethernet encapsulation, allows 271 grouping of several ethernet frames into one USB transfer and 272 different alignment possibilities. 273 274config USB_CONFIGFS_ECM 275 bool "Ethernet Control Model (CDC ECM)" 276 depends on USB_CONFIGFS 277 depends on NET 278 select USB_U_ETHER 279 select USB_F_ECM 280 help 281 The "Communication Device Class" (CDC) Ethernet Control Model. 282 That protocol is often avoided with pure Ethernet adapters, in 283 favor of simpler vendor-specific hardware, but is widely 284 supported by firmware for smart network devices. 285 286config USB_CONFIGFS_ECM_SUBSET 287 bool "Ethernet Control Model (CDC ECM) subset" 288 depends on USB_CONFIGFS 289 depends on NET 290 select USB_U_ETHER 291 select USB_F_SUBSET 292 help 293 On hardware that can't implement the full protocol, 294 a simple CDC subset is used, placing fewer demands on USB. 295 296config USB_CONFIGFS_RNDIS 297 bool "RNDIS" 298 depends on USB_CONFIGFS 299 depends on NET 300 select USB_U_ETHER 301 select USB_F_RNDIS 302 help 303 Microsoft Windows XP bundles the "Remote NDIS" (RNDIS) protocol, 304 and Microsoft provides redistributable binary RNDIS drivers for 305 older versions of Windows. 306 307 To make MS-Windows work with this, use Documentation/usb/linux.inf 308 as the "driver info file". For versions of MS-Windows older than 309 XP, you'll need to download drivers from Microsoft's website; a URL 310 is given in comments found in that info file. 311 312config USB_CONFIGFS_EEM 313 bool "Ethernet Emulation Model (EEM)" 314 depends on USB_CONFIGFS 315 depends on NET 316 select USB_U_ETHER 317 select USB_F_EEM 318 select CRC32 319 help 320 CDC EEM is a newer USB standard that is somewhat simpler than CDC ECM 321 and therefore can be supported by more hardware. Technically ECM and 322 EEM are designed for different applications. The ECM model extends 323 the network interface to the target (e.g. a USB cable modem), and the 324 EEM model is for mobile devices to communicate with hosts using 325 ethernet over USB. For Linux gadgets, however, the interface with 326 the host is the same (a usbX device), so the differences are minimal. 327 328config USB_CONFIGFS_PHONET 329 bool "Phonet protocol" 330 depends on USB_CONFIGFS 331 depends on NET 332 depends on PHONET 333 select USB_U_ETHER 334 select USB_F_PHONET 335 help 336 The Phonet protocol implementation for USB device. 337 338config USB_CONFIGFS_MASS_STORAGE 339 bool "Mass storage" 340 depends on USB_CONFIGFS 341 depends on BLOCK 342 select USB_F_MASS_STORAGE 343 help 344 The Mass Storage Gadget acts as a USB Mass Storage disk drive. 345 As its storage repository it can use a regular file or a block 346 device (in much the same way as the "loop" device driver), 347 specified as a module parameter or sysfs option. 348 349config USB_CONFIGFS_F_LB_SS 350 bool "Loopback and sourcesink function (for testing)" 351 depends on USB_CONFIGFS 352 select USB_F_SS_LB 353 help 354 Loopback function loops back a configurable number of transfers. 355 Sourcesink function either sinks and sources bulk data. 356 It also implements control requests, for "chapter 9" conformance. 357 Make this be the first driver you try using on top of any new 358 USB peripheral controller driver. Then you can use host-side 359 test software, like the "usbtest" driver, to put your hardware 360 and its driver through a basic set of functional tests. 361 362config USB_CONFIGFS_F_FS 363 bool "Function filesystem (FunctionFS)" 364 depends on USB_CONFIGFS 365 select USB_F_FS 366 help 367 The Function Filesystem (FunctionFS) lets one create USB 368 composite functions in user space in the same way GadgetFS 369 lets one create USB gadgets in user space. This allows creation 370 of composite gadgets such that some of the functions are 371 implemented in kernel space (for instance Ethernet, serial or 372 mass storage) and other are implemented in user space. 373 374config USB_CONFIGFS_F_UAC1 375 bool "Audio Class 1.0" 376 depends on USB_CONFIGFS 377 depends on SND 378 select USB_LIBCOMPOSITE 379 select SND_PCM 380 select USB_U_AUDIO 381 select USB_F_UAC1 382 help 383 This Audio function implements 1 AudioControl interface, 384 1 AudioStreaming Interface each for USB-OUT and USB-IN. 385 This driver doesn't expect any real Audio codec to be present 386 on the device - the audio streams are simply sinked to and 387 sourced from a virtual ALSA sound card created. The user-space 388 application may choose to do whatever it wants with the data 389 received from the USB Host and choose to provide whatever it 390 wants as audio data to the USB Host. 391 392config USB_CONFIGFS_F_UAC1_LEGACY 393 bool "Audio Class 1.0 (legacy implementation)" 394 depends on USB_CONFIGFS 395 depends on SND 396 select USB_LIBCOMPOSITE 397 select SND_PCM 398 select USB_F_UAC1_LEGACY 399 help 400 This Audio function implements 1 AudioControl interface, 401 1 AudioStreaming Interface each for USB-OUT and USB-IN. 402 This is a legacy driver and requires a real Audio codec 403 to be present on the device. 404 405config USB_CONFIGFS_F_UAC2 406 bool "Audio Class 2.0" 407 depends on USB_CONFIGFS 408 depends on SND 409 select USB_LIBCOMPOSITE 410 select SND_PCM 411 select USB_U_AUDIO 412 select USB_F_UAC2 413 help 414 This Audio function is compatible with USB Audio Class 415 specification 2.0. It implements 1 AudioControl interface, 416 1 AudioStreaming Interface each for USB-OUT and USB-IN. 417 This driver doesn't expect any real Audio codec to be present 418 on the device - the audio streams are simply sinked to and 419 sourced from a virtual ALSA sound card created. The user-space 420 application may choose to do whatever it wants with the data 421 received from the USB Host and choose to provide whatever it 422 wants as audio data to the USB Host. 423 424config USB_CONFIGFS_F_MIDI 425 bool "MIDI function" 426 depends on USB_CONFIGFS 427 depends on SND 428 select USB_LIBCOMPOSITE 429 select SND_RAWMIDI 430 select USB_F_MIDI 431 help 432 The MIDI Function acts as a USB Audio device, with one MIDI 433 input and one MIDI output. These MIDI jacks appear as 434 a sound "card" in the ALSA sound system. Other MIDI 435 connections can then be made on the gadget system, using 436 ALSA's aconnect utility etc. 437 438config USB_CONFIGFS_F_HID 439 bool "HID function" 440 depends on USB_CONFIGFS 441 select USB_F_HID 442 help 443 The HID function driver provides generic emulation of USB 444 Human Interface Devices (HID). 445 446 For more information, see Documentation/usb/gadget_hid.rst. 447 448config USB_CONFIGFS_F_UVC 449 bool "USB Webcam function" 450 depends on USB_CONFIGFS 451 depends on VIDEO_V4L2 452 depends on VIDEO_DEV 453 select VIDEOBUF2_DMA_SG 454 select VIDEOBUF2_VMALLOC 455 select USB_F_UVC 456 help 457 The Webcam function acts as a composite USB Audio and Video Class 458 device. It provides a userspace API to process UVC control requests 459 and stream video data to the host. 460 461config USB_CONFIGFS_F_PRINTER 462 bool "Printer function" 463 select USB_F_PRINTER 464 depends on USB_CONFIGFS 465 help 466 The Printer function channels data between the USB host and a 467 userspace program driving the print engine. The user space 468 program reads and writes the device file /dev/g_printer<X> to 469 receive or send printer data. It can use ioctl calls to 470 the device file to get or set printer status. 471 472 For more information, see Documentation/usb/gadget_printer.rst 473 which includes sample code for accessing the device file. 474 475config USB_CONFIGFS_F_TCM 476 bool "USB Gadget Target Fabric" 477 depends on TARGET_CORE 478 depends on USB_CONFIGFS 479 select USB_LIBCOMPOSITE 480 select USB_F_TCM 481 help 482 This fabric is a USB gadget component. Two USB protocols are 483 supported that is BBB or BOT (Bulk Only Transport) and UAS 484 (USB Attached SCSI). BOT is advertised on alternative 485 interface 0 (primary) and UAS is on alternative interface 1. 486 Both protocols can work on USB2.0 and USB3.0. 487 UAS utilizes the USB 3.0 feature called streams support. 488 489source "drivers/usb/gadget/legacy/Kconfig" 490 491endif # USB_GADGET 492