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 select UVC_COMMON 207 208config USB_F_MIDI 209 tristate 210 211config USB_F_HID 212 tristate 213 214config USB_F_PRINTER 215 tristate 216 217config USB_F_TCM 218 tristate 219 220# this first set of drivers all depend on bulk-capable hardware. 221 222config USB_CONFIGFS 223 tristate "USB Gadget functions configurable through configfs" 224 select USB_LIBCOMPOSITE 225 help 226 A Linux USB "gadget" can be set up through configfs. 227 If this is the case, the USB functions (which from the host's 228 perspective are seen as interfaces) and configurations are 229 specified simply by creating appropriate directories in configfs. 230 Associating functions with configurations is done by creating 231 appropriate symbolic links. 232 For more information see Documentation/usb/gadget_configfs.rst. 233 234config USB_CONFIGFS_SERIAL 235 bool "Generic serial bulk in/out" 236 depends on USB_CONFIGFS 237 depends on TTY 238 select USB_U_SERIAL 239 select USB_F_SERIAL 240 help 241 The function talks to the Linux-USB generic serial driver. 242 243config USB_CONFIGFS_ACM 244 bool "Abstract Control Model (CDC ACM)" 245 depends on USB_CONFIGFS 246 depends on TTY 247 select USB_U_SERIAL 248 select USB_F_ACM 249 help 250 ACM serial link. This function can be used to interoperate with 251 MS-Windows hosts or with the Linux-USB "cdc-acm" driver. 252 253config USB_CONFIGFS_OBEX 254 bool "Object Exchange Model (CDC OBEX)" 255 depends on USB_CONFIGFS 256 depends on TTY 257 select USB_U_SERIAL 258 select USB_F_OBEX 259 help 260 You will need a user space OBEX server talking to /dev/ttyGS*, 261 since the kernel itself doesn't implement the OBEX protocol. 262 263config USB_CONFIGFS_NCM 264 bool "Network Control Model (CDC NCM)" 265 depends on USB_CONFIGFS 266 depends on NET 267 select USB_U_ETHER 268 select USB_F_NCM 269 select CRC32 270 help 271 NCM is an advanced protocol for Ethernet encapsulation, allows 272 grouping of several ethernet frames into one USB transfer and 273 different alignment possibilities. 274 275config USB_CONFIGFS_ECM 276 bool "Ethernet Control Model (CDC ECM)" 277 depends on USB_CONFIGFS 278 depends on NET 279 select USB_U_ETHER 280 select USB_F_ECM 281 help 282 The "Communication Device Class" (CDC) Ethernet Control Model. 283 That protocol is often avoided with pure Ethernet adapters, in 284 favor of simpler vendor-specific hardware, but is widely 285 supported by firmware for smart network devices. 286 287config USB_CONFIGFS_ECM_SUBSET 288 bool "Ethernet Control Model (CDC ECM) subset" 289 depends on USB_CONFIGFS 290 depends on NET 291 select USB_U_ETHER 292 select USB_F_SUBSET 293 help 294 On hardware that can't implement the full protocol, 295 a simple CDC subset is used, placing fewer demands on USB. 296 297config USB_CONFIGFS_RNDIS 298 bool "RNDIS" 299 depends on USB_CONFIGFS 300 depends on NET 301 select USB_U_ETHER 302 select USB_F_RNDIS 303 help 304 Microsoft Windows XP bundles the "Remote NDIS" (RNDIS) protocol, 305 and Microsoft provides redistributable binary RNDIS drivers for 306 older versions of Windows. 307 308 To make MS-Windows work with this, use Documentation/usb/linux.inf 309 as the "driver info file". For versions of MS-Windows older than 310 XP, you'll need to download drivers from Microsoft's website; a URL 311 is given in comments found in that info file. 312 313config USB_CONFIGFS_EEM 314 bool "Ethernet Emulation Model (EEM)" 315 depends on USB_CONFIGFS 316 depends on NET 317 select USB_U_ETHER 318 select USB_F_EEM 319 select CRC32 320 help 321 CDC EEM is a newer USB standard that is somewhat simpler than CDC ECM 322 and therefore can be supported by more hardware. Technically ECM and 323 EEM are designed for different applications. The ECM model extends 324 the network interface to the target (e.g. a USB cable modem), and the 325 EEM model is for mobile devices to communicate with hosts using 326 ethernet over USB. For Linux gadgets, however, the interface with 327 the host is the same (a usbX device), so the differences are minimal. 328 329config USB_CONFIGFS_PHONET 330 bool "Phonet protocol" 331 depends on USB_CONFIGFS 332 depends on NET 333 depends on PHONET 334 select USB_U_ETHER 335 select USB_F_PHONET 336 help 337 The Phonet protocol implementation for USB device. 338 339config USB_CONFIGFS_MASS_STORAGE 340 bool "Mass storage" 341 depends on USB_CONFIGFS 342 depends on BLOCK 343 select USB_F_MASS_STORAGE 344 help 345 The Mass Storage Gadget acts as a USB Mass Storage disk drive. 346 As its storage repository it can use a regular file or a block 347 device (in much the same way as the "loop" device driver), 348 specified as a module parameter or sysfs option. 349 350config USB_CONFIGFS_F_LB_SS 351 bool "Loopback and sourcesink function (for testing)" 352 depends on USB_CONFIGFS 353 select USB_F_SS_LB 354 help 355 Loopback function loops back a configurable number of transfers. 356 Sourcesink function either sinks and sources bulk data. 357 It also implements control requests, for "chapter 9" conformance. 358 Make this be the first driver you try using on top of any new 359 USB peripheral controller driver. Then you can use host-side 360 test software, like the "usbtest" driver, to put your hardware 361 and its driver through a basic set of functional tests. 362 363config USB_CONFIGFS_F_FS 364 bool "Function filesystem (FunctionFS)" 365 depends on USB_CONFIGFS 366 select USB_F_FS 367 help 368 The Function Filesystem (FunctionFS) lets one create USB 369 composite functions in user space in the same way GadgetFS 370 lets one create USB gadgets in user space. This allows creation 371 of composite gadgets such that some of the functions are 372 implemented in kernel space (for instance Ethernet, serial or 373 mass storage) and other are implemented in user space. 374 375config USB_CONFIGFS_F_UAC1 376 bool "Audio Class 1.0" 377 depends on USB_CONFIGFS 378 depends on SND 379 select USB_LIBCOMPOSITE 380 select SND_PCM 381 select USB_U_AUDIO 382 select USB_F_UAC1 383 help 384 This Audio function implements 1 AudioControl interface, 385 1 AudioStreaming Interface each for USB-OUT and USB-IN. 386 This driver doesn't expect any real Audio codec to be present 387 on the device - the audio streams are simply sinked to and 388 sourced from a virtual ALSA sound card created. The user-space 389 application may choose to do whatever it wants with the data 390 received from the USB Host and choose to provide whatever it 391 wants as audio data to the USB Host. 392 393config USB_CONFIGFS_F_UAC1_LEGACY 394 bool "Audio Class 1.0 (legacy implementation)" 395 depends on USB_CONFIGFS 396 depends on SND 397 select USB_LIBCOMPOSITE 398 select SND_PCM 399 select USB_F_UAC1_LEGACY 400 help 401 This Audio function implements 1 AudioControl interface, 402 1 AudioStreaming Interface each for USB-OUT and USB-IN. 403 This is a legacy driver and requires a real Audio codec 404 to be present on the device. 405 406config USB_CONFIGFS_F_UAC2 407 bool "Audio Class 2.0" 408 depends on USB_CONFIGFS 409 depends on SND 410 select USB_LIBCOMPOSITE 411 select SND_PCM 412 select USB_U_AUDIO 413 select USB_F_UAC2 414 help 415 This Audio function is compatible with USB Audio Class 416 specification 2.0. It implements 1 AudioControl interface, 417 1 AudioStreaming Interface each for USB-OUT and USB-IN. 418 This driver doesn't expect any real Audio codec to be present 419 on the device - the audio streams are simply sinked to and 420 sourced from a virtual ALSA sound card created. The user-space 421 application may choose to do whatever it wants with the data 422 received from the USB Host and choose to provide whatever it 423 wants as audio data to the USB Host. 424 425config USB_CONFIGFS_F_MIDI 426 bool "MIDI function" 427 depends on USB_CONFIGFS 428 depends on SND 429 select USB_LIBCOMPOSITE 430 select SND_RAWMIDI 431 select USB_F_MIDI 432 help 433 The MIDI Function acts as a USB Audio device, with one MIDI 434 input and one MIDI output. These MIDI jacks appear as 435 a sound "card" in the ALSA sound system. Other MIDI 436 connections can then be made on the gadget system, using 437 ALSA's aconnect utility etc. 438 439config USB_CONFIGFS_F_HID 440 bool "HID function" 441 depends on USB_CONFIGFS 442 select USB_F_HID 443 help 444 The HID function driver provides generic emulation of USB 445 Human Interface Devices (HID). 446 447 For more information, see Documentation/usb/gadget_hid.rst. 448 449config USB_CONFIGFS_F_UVC 450 bool "USB Webcam function" 451 depends on USB_CONFIGFS 452 depends on VIDEO_DEV 453 depends on VIDEO_DEV 454 select VIDEOBUF2_DMA_SG 455 select VIDEOBUF2_VMALLOC 456 select USB_F_UVC 457 help 458 The Webcam function acts as a composite USB Audio and Video Class 459 device. It provides a userspace API to process UVC control requests 460 and stream video data to the host. 461 462config USB_CONFIGFS_F_PRINTER 463 bool "Printer function" 464 select USB_F_PRINTER 465 depends on USB_CONFIGFS 466 help 467 The Printer function channels data between the USB host and a 468 userspace program driving the print engine. The user space 469 program reads and writes the device file /dev/g_printer<X> to 470 receive or send printer data. It can use ioctl calls to 471 the device file to get or set printer status. 472 473 For more information, see Documentation/usb/gadget_printer.rst 474 which includes sample code for accessing the device file. 475 476config USB_CONFIGFS_F_TCM 477 bool "USB Gadget Target Fabric" 478 depends on TARGET_CORE 479 depends on USB_CONFIGFS 480 select USB_LIBCOMPOSITE 481 select USB_F_TCM 482 help 483 This fabric is a USB gadget component. Two USB protocols are 484 supported that is BBB or BOT (Bulk Only Transport) and UAS 485 (USB Attached SCSI). BOT is advertised on alternative 486 interface 0 (primary) and UAS is on alternative interface 1. 487 Both protocols can work on USB2.0 and USB3.0. 488 UAS utilizes the USB 3.0 feature called streams support. 489 490source "drivers/usb/gadget/legacy/Kconfig" 491 492endif # USB_GADGET 493