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 select DMA_SHARED_BUFFER 194 tristate 195 196config USB_F_UAC1 197 tristate 198 199config USB_F_UAC1_LEGACY 200 tristate 201 202config USB_F_UAC2 203 tristate 204 205config USB_F_UVC 206 tristate 207 select UVC_COMMON 208 209config USB_F_MIDI 210 tristate 211 212config USB_F_MIDI2 213 tristate 214 select SND_UMP 215 select SND_UMP_LEGACY_RAWMIDI 216 217config USB_F_HID 218 tristate 219 220config USB_F_PRINTER 221 tristate 222 223config USB_F_TCM 224 tristate 225 226# this first set of drivers all depend on bulk-capable hardware. 227 228config USB_CONFIGFS 229 tristate "USB Gadget functions configurable through configfs" 230 select USB_LIBCOMPOSITE 231 help 232 A Linux USB "gadget" can be set up through configfs. 233 If this is the case, the USB functions (which from the host's 234 perspective are seen as interfaces) and configurations are 235 specified simply by creating appropriate directories in configfs. 236 Associating functions with configurations is done by creating 237 appropriate symbolic links. 238 For more information see Documentation/usb/gadget_configfs.rst. 239 240config USB_CONFIGFS_SERIAL 241 bool "Generic serial bulk in/out" 242 depends on USB_CONFIGFS 243 depends on TTY 244 select USB_U_SERIAL 245 select USB_F_SERIAL 246 help 247 The function talks to the Linux-USB generic serial driver. 248 249config USB_CONFIGFS_ACM 250 bool "Abstract Control Model (CDC ACM)" 251 depends on USB_CONFIGFS 252 depends on TTY 253 select USB_U_SERIAL 254 select USB_F_ACM 255 help 256 ACM serial link. This function can be used to interoperate with 257 MS-Windows hosts or with the Linux-USB "cdc-acm" driver. 258 259config USB_CONFIGFS_OBEX 260 bool "Object Exchange Model (CDC OBEX)" 261 depends on USB_CONFIGFS 262 depends on TTY 263 select USB_U_SERIAL 264 select USB_F_OBEX 265 help 266 You will need a user space OBEX server talking to /dev/ttyGS*, 267 since the kernel itself doesn't implement the OBEX protocol. 268 269config USB_CONFIGFS_NCM 270 bool "Network Control Model (CDC NCM)" 271 depends on USB_CONFIGFS 272 depends on NET 273 select USB_U_ETHER 274 select USB_F_NCM 275 select CRC32 276 help 277 NCM is an advanced protocol for Ethernet encapsulation, allows 278 grouping of several ethernet frames into one USB transfer and 279 different alignment possibilities. 280 281config USB_CONFIGFS_ECM 282 bool "Ethernet Control Model (CDC ECM)" 283 depends on USB_CONFIGFS 284 depends on NET 285 select USB_U_ETHER 286 select USB_F_ECM 287 help 288 The "Communication Device Class" (CDC) Ethernet Control Model. 289 That protocol is often avoided with pure Ethernet adapters, in 290 favor of simpler vendor-specific hardware, but is widely 291 supported by firmware for smart network devices. 292 293config USB_CONFIGFS_ECM_SUBSET 294 bool "Ethernet Control Model (CDC ECM) subset" 295 depends on USB_CONFIGFS 296 depends on NET 297 select USB_U_ETHER 298 select USB_F_SUBSET 299 help 300 On hardware that can't implement the full protocol, 301 a simple CDC subset is used, placing fewer demands on USB. 302 303config USB_CONFIGFS_RNDIS 304 bool "RNDIS" 305 depends on USB_CONFIGFS 306 depends on NET 307 select USB_U_ETHER 308 select USB_F_RNDIS 309 help 310 Microsoft Windows XP bundles the "Remote NDIS" (RNDIS) protocol, 311 and Microsoft provides redistributable binary RNDIS drivers for 312 older versions of Windows. 313 314 To make MS-Windows work with this, use Documentation/usb/linux.inf 315 as the "driver info file". For versions of MS-Windows older than 316 XP, you'll need to download drivers from Microsoft's website; a URL 317 is given in comments found in that info file. 318 319config USB_CONFIGFS_EEM 320 bool "Ethernet Emulation Model (EEM)" 321 depends on USB_CONFIGFS 322 depends on NET 323 select USB_U_ETHER 324 select USB_F_EEM 325 select CRC32 326 help 327 CDC EEM is a newer USB standard that is somewhat simpler than CDC ECM 328 and therefore can be supported by more hardware. Technically ECM and 329 EEM are designed for different applications. The ECM model extends 330 the network interface to the target (e.g. a USB cable modem), and the 331 EEM model is for mobile devices to communicate with hosts using 332 ethernet over USB. For Linux gadgets, however, the interface with 333 the host is the same (a usbX device), so the differences are minimal. 334 335config USB_CONFIGFS_PHONET 336 bool "Phonet protocol" 337 depends on USB_CONFIGFS 338 depends on NET 339 depends on PHONET 340 select USB_U_ETHER 341 select USB_F_PHONET 342 help 343 The Phonet protocol implementation for USB device. 344 345config USB_CONFIGFS_MASS_STORAGE 346 bool "Mass storage" 347 depends on USB_CONFIGFS 348 depends on BLOCK 349 select USB_F_MASS_STORAGE 350 help 351 The Mass Storage Gadget acts as a USB Mass Storage disk drive. 352 As its storage repository it can use a regular file or a block 353 device (in much the same way as the "loop" device driver), 354 specified as a module parameter or sysfs option. 355 356config USB_CONFIGFS_F_LB_SS 357 bool "Loopback and sourcesink function (for testing)" 358 depends on USB_CONFIGFS 359 select USB_F_SS_LB 360 help 361 Loopback function loops back a configurable number of transfers. 362 Sourcesink function either sinks and sources bulk data. 363 It also implements control requests, for "chapter 9" conformance. 364 Make this be the first driver you try using on top of any new 365 USB peripheral controller driver. Then you can use host-side 366 test software, like the "usbtest" driver, to put your hardware 367 and its driver through a basic set of functional tests. 368 369config USB_CONFIGFS_F_FS 370 bool "Function filesystem (FunctionFS)" 371 depends on USB_CONFIGFS 372 select USB_F_FS 373 help 374 The Function Filesystem (FunctionFS) lets one create USB 375 composite functions in user space in the same way GadgetFS 376 lets one create USB gadgets in user space. This allows creation 377 of composite gadgets such that some of the functions are 378 implemented in kernel space (for instance Ethernet, serial or 379 mass storage) and other are implemented in user space. 380 381config USB_CONFIGFS_F_UAC1 382 bool "Audio Class 1.0" 383 depends on USB_CONFIGFS 384 depends on SND 385 select USB_LIBCOMPOSITE 386 select SND_PCM 387 select USB_U_AUDIO 388 select USB_F_UAC1 389 help 390 This Audio function implements 1 AudioControl interface, 391 1 AudioStreaming Interface each for USB-OUT and USB-IN. 392 This driver doesn't expect any real Audio codec to be present 393 on the device - the audio streams are simply sinked to and 394 sourced from a virtual ALSA sound card created. The user-space 395 application may choose to do whatever it wants with the data 396 received from the USB Host and choose to provide whatever it 397 wants as audio data to the USB Host. 398 399config USB_CONFIGFS_F_UAC1_LEGACY 400 bool "Audio Class 1.0 (legacy implementation)" 401 depends on USB_CONFIGFS 402 depends on SND 403 select USB_LIBCOMPOSITE 404 select SND_PCM 405 select USB_F_UAC1_LEGACY 406 help 407 This Audio function implements 1 AudioControl interface, 408 1 AudioStreaming Interface each for USB-OUT and USB-IN. 409 This is a legacy driver and requires a real Audio codec 410 to be present on the device. 411 412config USB_CONFIGFS_F_UAC2 413 bool "Audio Class 2.0" 414 depends on USB_CONFIGFS 415 depends on SND 416 select USB_LIBCOMPOSITE 417 select SND_PCM 418 select USB_U_AUDIO 419 select USB_F_UAC2 420 help 421 This Audio function is compatible with USB Audio Class 422 specification 2.0. It implements 1 AudioControl interface, 423 1 AudioStreaming Interface each for USB-OUT and USB-IN. 424 This driver doesn't expect any real Audio codec to be present 425 on the device - the audio streams are simply sinked to and 426 sourced from a virtual ALSA sound card created. The user-space 427 application may choose to do whatever it wants with the data 428 received from the USB Host and choose to provide whatever it 429 wants as audio data to the USB Host. 430 431config USB_CONFIGFS_F_MIDI 432 bool "MIDI function" 433 depends on USB_CONFIGFS 434 depends on SND 435 select USB_LIBCOMPOSITE 436 select SND_RAWMIDI 437 select USB_F_MIDI 438 help 439 The MIDI Function acts as a USB Audio device, with one MIDI 440 input and one MIDI output. These MIDI jacks appear as 441 a sound "card" in the ALSA sound system. Other MIDI 442 connections can then be made on the gadget system, using 443 ALSA's aconnect utility etc. 444 445config USB_CONFIGFS_F_MIDI2 446 bool "MIDI 2.0 function" 447 depends on USB_CONFIGFS 448 depends on SND 449 select USB_LIBCOMPOSITE 450 select USB_F_MIDI2 451 help 452 The MIDI 2.0 function driver provides the generic emulated 453 USB MIDI 2.0 interface, looped back to ALSA UMP rawmidi 454 device on the gadget host. It supports UMP 1.1 spec and 455 responds UMP Stream messages for UMP Endpoint and Function 456 Block information / configuration. 457 458config USB_CONFIGFS_F_HID 459 bool "HID function" 460 depends on USB_CONFIGFS 461 select USB_F_HID 462 help 463 The HID function driver provides generic emulation of USB 464 Human Interface Devices (HID). 465 466 For more information, see Documentation/usb/gadget_hid.rst. 467 468config USB_CONFIGFS_F_UVC 469 bool "USB Webcam function" 470 depends on USB_CONFIGFS 471 depends on VIDEO_DEV 472 depends on VIDEO_DEV 473 select VIDEOBUF2_DMA_SG 474 select VIDEOBUF2_VMALLOC 475 select USB_F_UVC 476 help 477 The Webcam function acts as a composite USB Audio and Video Class 478 device. It provides a userspace API to process UVC control requests 479 and stream video data to the host. 480 481config USB_CONFIGFS_F_PRINTER 482 bool "Printer function" 483 select USB_F_PRINTER 484 depends on USB_CONFIGFS 485 help 486 The Printer function channels data between the USB host and a 487 userspace program driving the print engine. The user space 488 program reads and writes the device file /dev/g_printer<X> to 489 receive or send printer data. It can use ioctl calls to 490 the device file to get or set printer status. 491 492 For more information, see Documentation/usb/gadget_printer.rst 493 which includes sample code for accessing the device file. 494 495config USB_CONFIGFS_F_TCM 496 bool "USB Gadget Target Fabric" 497 depends on TARGET_CORE 498 depends on USB_CONFIGFS 499 select USB_LIBCOMPOSITE 500 select USB_F_TCM 501 help 502 This fabric is a USB gadget component. Two USB protocols are 503 supported that is BBB or BOT (Bulk Only Transport) and UAS 504 (USB Attached SCSI). BOT is advertised on alternative 505 interface 0 (primary) and UAS is on alternative interface 1. 506 Both protocols can work on USB2.0 and USB3.0. 507 UAS utilizes the USB 3.0 feature called streams support. 508 509source "drivers/usb/gadget/legacy/Kconfig" 510 511endif # USB_GADGET 512