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_MIDI2 212 tristate 213 214config USB_F_HID 215 tristate 216 217config USB_F_PRINTER 218 tristate 219 220config USB_F_TCM 221 tristate 222 223# this first set of drivers all depend on bulk-capable hardware. 224 225config USB_CONFIGFS 226 tristate "USB Gadget functions configurable through configfs" 227 select USB_LIBCOMPOSITE 228 help 229 A Linux USB "gadget" can be set up through configfs. 230 If this is the case, the USB functions (which from the host's 231 perspective are seen as interfaces) and configurations are 232 specified simply by creating appropriate directories in configfs. 233 Associating functions with configurations is done by creating 234 appropriate symbolic links. 235 For more information see Documentation/usb/gadget_configfs.rst. 236 237config USB_CONFIGFS_SERIAL 238 bool "Generic serial bulk in/out" 239 depends on USB_CONFIGFS 240 depends on TTY 241 select USB_U_SERIAL 242 select USB_F_SERIAL 243 help 244 The function talks to the Linux-USB generic serial driver. 245 246config USB_CONFIGFS_ACM 247 bool "Abstract Control Model (CDC ACM)" 248 depends on USB_CONFIGFS 249 depends on TTY 250 select USB_U_SERIAL 251 select USB_F_ACM 252 help 253 ACM serial link. This function can be used to interoperate with 254 MS-Windows hosts or with the Linux-USB "cdc-acm" driver. 255 256config USB_CONFIGFS_OBEX 257 bool "Object Exchange Model (CDC OBEX)" 258 depends on USB_CONFIGFS 259 depends on TTY 260 select USB_U_SERIAL 261 select USB_F_OBEX 262 help 263 You will need a user space OBEX server talking to /dev/ttyGS*, 264 since the kernel itself doesn't implement the OBEX protocol. 265 266config USB_CONFIGFS_NCM 267 bool "Network Control Model (CDC NCM)" 268 depends on USB_CONFIGFS 269 depends on NET 270 select USB_U_ETHER 271 select USB_F_NCM 272 select CRC32 273 help 274 NCM is an advanced protocol for Ethernet encapsulation, allows 275 grouping of several ethernet frames into one USB transfer and 276 different alignment possibilities. 277 278config USB_CONFIGFS_ECM 279 bool "Ethernet Control Model (CDC ECM)" 280 depends on USB_CONFIGFS 281 depends on NET 282 select USB_U_ETHER 283 select USB_F_ECM 284 help 285 The "Communication Device Class" (CDC) Ethernet Control Model. 286 That protocol is often avoided with pure Ethernet adapters, in 287 favor of simpler vendor-specific hardware, but is widely 288 supported by firmware for smart network devices. 289 290config USB_CONFIGFS_ECM_SUBSET 291 bool "Ethernet Control Model (CDC ECM) subset" 292 depends on USB_CONFIGFS 293 depends on NET 294 select USB_U_ETHER 295 select USB_F_SUBSET 296 help 297 On hardware that can't implement the full protocol, 298 a simple CDC subset is used, placing fewer demands on USB. 299 300config USB_CONFIGFS_RNDIS 301 bool "RNDIS" 302 depends on USB_CONFIGFS 303 depends on NET 304 select USB_U_ETHER 305 select USB_F_RNDIS 306 help 307 Microsoft Windows XP bundles the "Remote NDIS" (RNDIS) protocol, 308 and Microsoft provides redistributable binary RNDIS drivers for 309 older versions of Windows. 310 311 To make MS-Windows work with this, use Documentation/usb/linux.inf 312 as the "driver info file". For versions of MS-Windows older than 313 XP, you'll need to download drivers from Microsoft's website; a URL 314 is given in comments found in that info file. 315 316config USB_CONFIGFS_EEM 317 bool "Ethernet Emulation Model (EEM)" 318 depends on USB_CONFIGFS 319 depends on NET 320 select USB_U_ETHER 321 select USB_F_EEM 322 select CRC32 323 help 324 CDC EEM is a newer USB standard that is somewhat simpler than CDC ECM 325 and therefore can be supported by more hardware. Technically ECM and 326 EEM are designed for different applications. The ECM model extends 327 the network interface to the target (e.g. a USB cable modem), and the 328 EEM model is for mobile devices to communicate with hosts using 329 ethernet over USB. For Linux gadgets, however, the interface with 330 the host is the same (a usbX device), so the differences are minimal. 331 332config USB_CONFIGFS_PHONET 333 bool "Phonet protocol" 334 depends on USB_CONFIGFS 335 depends on NET 336 depends on PHONET 337 select USB_U_ETHER 338 select USB_F_PHONET 339 help 340 The Phonet protocol implementation for USB device. 341 342config USB_CONFIGFS_MASS_STORAGE 343 bool "Mass storage" 344 depends on USB_CONFIGFS 345 depends on BLOCK 346 select USB_F_MASS_STORAGE 347 help 348 The Mass Storage Gadget acts as a USB Mass Storage disk drive. 349 As its storage repository it can use a regular file or a block 350 device (in much the same way as the "loop" device driver), 351 specified as a module parameter or sysfs option. 352 353config USB_CONFIGFS_F_LB_SS 354 bool "Loopback and sourcesink function (for testing)" 355 depends on USB_CONFIGFS 356 select USB_F_SS_LB 357 help 358 Loopback function loops back a configurable number of transfers. 359 Sourcesink function either sinks and sources bulk data. 360 It also implements control requests, for "chapter 9" conformance. 361 Make this be the first driver you try using on top of any new 362 USB peripheral controller driver. Then you can use host-side 363 test software, like the "usbtest" driver, to put your hardware 364 and its driver through a basic set of functional tests. 365 366config USB_CONFIGFS_F_FS 367 bool "Function filesystem (FunctionFS)" 368 depends on USB_CONFIGFS 369 select USB_F_FS 370 help 371 The Function Filesystem (FunctionFS) lets one create USB 372 composite functions in user space in the same way GadgetFS 373 lets one create USB gadgets in user space. This allows creation 374 of composite gadgets such that some of the functions are 375 implemented in kernel space (for instance Ethernet, serial or 376 mass storage) and other are implemented in user space. 377 378config USB_CONFIGFS_F_UAC1 379 bool "Audio Class 1.0" 380 depends on USB_CONFIGFS 381 depends on SND 382 select USB_LIBCOMPOSITE 383 select SND_PCM 384 select USB_U_AUDIO 385 select USB_F_UAC1 386 help 387 This Audio function implements 1 AudioControl interface, 388 1 AudioStreaming Interface each for USB-OUT and USB-IN. 389 This driver doesn't expect any real Audio codec to be present 390 on the device - the audio streams are simply sinked to and 391 sourced from a virtual ALSA sound card created. The user-space 392 application may choose to do whatever it wants with the data 393 received from the USB Host and choose to provide whatever it 394 wants as audio data to the USB Host. 395 396config USB_CONFIGFS_F_UAC1_LEGACY 397 bool "Audio Class 1.0 (legacy implementation)" 398 depends on USB_CONFIGFS 399 depends on SND 400 select USB_LIBCOMPOSITE 401 select SND_PCM 402 select USB_F_UAC1_LEGACY 403 help 404 This Audio function implements 1 AudioControl interface, 405 1 AudioStreaming Interface each for USB-OUT and USB-IN. 406 This is a legacy driver and requires a real Audio codec 407 to be present on the device. 408 409config USB_CONFIGFS_F_UAC2 410 bool "Audio Class 2.0" 411 depends on USB_CONFIGFS 412 depends on SND 413 select USB_LIBCOMPOSITE 414 select SND_PCM 415 select USB_U_AUDIO 416 select USB_F_UAC2 417 help 418 This Audio function is compatible with USB Audio Class 419 specification 2.0. It implements 1 AudioControl interface, 420 1 AudioStreaming Interface each for USB-OUT and USB-IN. 421 This driver doesn't expect any real Audio codec to be present 422 on the device - the audio streams are simply sinked to and 423 sourced from a virtual ALSA sound card created. The user-space 424 application may choose to do whatever it wants with the data 425 received from the USB Host and choose to provide whatever it 426 wants as audio data to the USB Host. 427 428config USB_CONFIGFS_F_MIDI 429 bool "MIDI function" 430 depends on USB_CONFIGFS 431 depends on SND 432 select USB_LIBCOMPOSITE 433 select SND_RAWMIDI 434 select USB_F_MIDI 435 help 436 The MIDI Function acts as a USB Audio device, with one MIDI 437 input and one MIDI output. These MIDI jacks appear as 438 a sound "card" in the ALSA sound system. Other MIDI 439 connections can then be made on the gadget system, using 440 ALSA's aconnect utility etc. 441 442config USB_CONFIGFS_F_MIDI2 443 bool "MIDI 2.0 function" 444 depends on USB_CONFIGFS 445 depends on SND 446 select USB_LIBCOMPOSITE 447 select SND_UMP 448 select SND_UMP_LEGACY_RAWMIDI 449 select USB_F_MIDI2 450 help 451 The MIDI 2.0 function driver provides the generic emulated 452 USB MIDI 2.0 interface, looped back to ALSA UMP rawmidi 453 device on the gadget host. It supports UMP 1.1 spec and 454 responds UMP Stream messages for UMP Endpoint and Function 455 Block information / configuration. 456 457config USB_CONFIGFS_F_HID 458 bool "HID function" 459 depends on USB_CONFIGFS 460 select USB_F_HID 461 help 462 The HID function driver provides generic emulation of USB 463 Human Interface Devices (HID). 464 465 For more information, see Documentation/usb/gadget_hid.rst. 466 467config USB_CONFIGFS_F_UVC 468 bool "USB Webcam function" 469 depends on USB_CONFIGFS 470 depends on VIDEO_DEV 471 depends on VIDEO_DEV 472 select VIDEOBUF2_DMA_SG 473 select VIDEOBUF2_VMALLOC 474 select USB_F_UVC 475 help 476 The Webcam function acts as a composite USB Audio and Video Class 477 device. It provides a userspace API to process UVC control requests 478 and stream video data to the host. 479 480config USB_CONFIGFS_F_PRINTER 481 bool "Printer function" 482 select USB_F_PRINTER 483 depends on USB_CONFIGFS 484 help 485 The Printer function channels data between the USB host and a 486 userspace program driving the print engine. The user space 487 program reads and writes the device file /dev/g_printer<X> to 488 receive or send printer data. It can use ioctl calls to 489 the device file to get or set printer status. 490 491 For more information, see Documentation/usb/gadget_printer.rst 492 which includes sample code for accessing the device file. 493 494config USB_CONFIGFS_F_TCM 495 bool "USB Gadget Target Fabric" 496 depends on TARGET_CORE 497 depends on USB_CONFIGFS 498 select USB_LIBCOMPOSITE 499 select USB_F_TCM 500 help 501 This fabric is a USB gadget component. Two USB protocols are 502 supported that is BBB or BOT (Bulk Only Transport) and UAS 503 (USB Attached SCSI). BOT is advertised on alternative 504 interface 0 (primary) and UAS is on alternative interface 1. 505 Both protocols can work on USB2.0 and USB3.0. 506 UAS utilizes the USB 3.0 feature called streams support. 507 508source "drivers/usb/gadget/legacy/Kconfig" 509 510endif # USB_GADGET 511