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 17 menuconfig 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 47 if USB_GADGET 48 49 config 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 63 config 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 77 config 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 88 config 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 99 config 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. 115 116 config 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. 131 132 config 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. 137 138 source "drivers/usb/gadget/udc/Kconfig" 139 140 # 141 # USB Gadget Drivers 142 # 143 144 # composite based drivers 145 config USB_LIBCOMPOSITE 146 tristate 147 select CONFIGFS_FS 148 depends on USB_GADGET 149 150 config USB_F_ACM 151 tristate 152 153 config USB_F_SS_LB 154 tristate 155 156 config USB_U_SERIAL 157 tristate 158 159 config USB_U_ETHER 160 tristate 161 162 config USB_U_AUDIO 163 tristate 164 165 config USB_F_SERIAL 166 tristate 167 168 config USB_F_OBEX 169 tristate 170 171 config USB_F_NCM 172 tristate 173 174 config USB_F_ECM 175 tristate 176 177 config USB_F_PHONET 178 tristate 179 180 config USB_F_EEM 181 tristate 182 183 config USB_F_SUBSET 184 tristate 185 186 config USB_F_RNDIS 187 tristate 188 189 config USB_F_MASS_STORAGE 190 tristate 191 192 config USB_F_FS 193 select DMA_SHARED_BUFFER 194 tristate 195 196 config USB_F_UAC1 197 tristate 198 199 config USB_F_UAC1_LEGACY 200 tristate 201 202 config USB_F_UAC2 203 tristate 204 205 config USB_F_UVC 206 tristate 207 select UVC_COMMON 208 209 config USB_F_MIDI 210 tristate 211 212 config USB_F_MIDI2 213 tristate 214 215 config USB_F_HID 216 tristate 217 218 config USB_F_PRINTER 219 tristate 220 221 config USB_F_TCM 222 tristate 223 224 # this first set of drivers all depend on bulk-capable hardware. 225 226 config USB_CONFIGFS 227 tristate "USB Gadget functions configurable through configfs" 228 select USB_LIBCOMPOSITE 229 help 230 A Linux USB "gadget" can be set up through configfs. 231 If this is the case, the USB functions (which from the host's 232 perspective are seen as interfaces) and configurations are 233 specified simply by creating appropriate directories in configfs. 234 Associating functions with configurations is done by creating 235 appropriate symbolic links. 236 For more information see Documentation/usb/gadget_configfs.rst. 237 238 config USB_CONFIGFS_SERIAL 239 bool "Generic serial bulk in/out" 240 depends on USB_CONFIGFS 241 depends on TTY 242 select USB_U_SERIAL 243 select USB_F_SERIAL 244 help 245 The function talks to the Linux-USB generic serial driver. 246 247 config USB_CONFIGFS_ACM 248 bool "Abstract Control Model (CDC ACM)" 249 depends on USB_CONFIGFS 250 depends on TTY 251 select USB_U_SERIAL 252 select USB_F_ACM 253 help 254 ACM serial link. This function can be used to interoperate with 255 MS-Windows hosts or with the Linux-USB "cdc-acm" driver. 256 257 config USB_CONFIGFS_OBEX 258 bool "Object Exchange Model (CDC OBEX)" 259 depends on USB_CONFIGFS 260 depends on TTY 261 select USB_U_SERIAL 262 select USB_F_OBEX 263 help 264 You will need a user space OBEX server talking to /dev/ttyGS*, 265 since the kernel itself doesn't implement the OBEX protocol. 266 267 config USB_CONFIGFS_NCM 268 bool "Network Control Model (CDC NCM)" 269 depends on USB_CONFIGFS 270 depends on NET 271 select USB_U_ETHER 272 select USB_F_NCM 273 select CRC32 274 help 275 NCM is an advanced protocol for Ethernet encapsulation, allows 276 grouping of several ethernet frames into one USB transfer and 277 different alignment possibilities. 278 279 config USB_CONFIGFS_ECM 280 bool "Ethernet Control Model (CDC ECM)" 281 depends on USB_CONFIGFS 282 depends on NET 283 select USB_U_ETHER 284 select USB_F_ECM 285 help 286 The "Communication Device Class" (CDC) Ethernet Control Model. 287 That protocol is often avoided with pure Ethernet adapters, in 288 favor of simpler vendor-specific hardware, but is widely 289 supported by firmware for smart network devices. 290 291 config USB_CONFIGFS_ECM_SUBSET 292 bool "Ethernet Control Model (CDC ECM) subset" 293 depends on USB_CONFIGFS 294 depends on NET 295 select USB_U_ETHER 296 select USB_F_SUBSET 297 help 298 On hardware that can't implement the full protocol, 299 a simple CDC subset is used, placing fewer demands on USB. 300 301 config USB_CONFIGFS_RNDIS 302 bool "RNDIS" 303 depends on USB_CONFIGFS 304 depends on NET 305 select USB_U_ETHER 306 select USB_F_RNDIS 307 help 308 Microsoft Windows XP bundles the "Remote NDIS" (RNDIS) protocol, 309 and Microsoft provides redistributable binary RNDIS drivers for 310 older versions of Windows. 311 312 To make MS-Windows work with this, use Documentation/usb/linux.inf 313 as the "driver info file". For versions of MS-Windows older than 314 XP, you'll need to download drivers from Microsoft's website; a URL 315 is given in comments found in that info file. 316 317 config USB_CONFIGFS_EEM 318 bool "Ethernet Emulation Model (EEM)" 319 depends on USB_CONFIGFS 320 depends on NET 321 select USB_U_ETHER 322 select USB_F_EEM 323 select CRC32 324 help 325 CDC EEM is a newer USB standard that is somewhat simpler than CDC ECM 326 and therefore can be supported by more hardware. Technically ECM and 327 EEM are designed for different applications. The ECM model extends 328 the network interface to the target (e.g. a USB cable modem), and the 329 EEM model is for mobile devices to communicate with hosts using 330 ethernet over USB. For Linux gadgets, however, the interface with 331 the host is the same (a usbX device), so the differences are minimal. 332 333 config USB_CONFIGFS_PHONET 334 bool "Phonet protocol" 335 depends on USB_CONFIGFS 336 depends on NET 337 depends on PHONET 338 select USB_U_ETHER 339 select USB_F_PHONET 340 help 341 The Phonet protocol implementation for USB device. 342 343 config USB_CONFIGFS_MASS_STORAGE 344 bool "Mass storage" 345 depends on USB_CONFIGFS 346 depends on BLOCK 347 select USB_F_MASS_STORAGE 348 help 349 The Mass Storage Gadget acts as a USB Mass Storage disk drive. 350 As its storage repository it can use a regular file or a block 351 device (in much the same way as the "loop" device driver), 352 specified as a module parameter or sysfs option. 353 354 config USB_CONFIGFS_F_LB_SS 355 bool "Loopback and sourcesink function (for testing)" 356 depends on USB_CONFIGFS 357 select USB_F_SS_LB 358 help 359 Loopback function loops back a configurable number of transfers. 360 Sourcesink function either sinks and sources bulk data. 361 It also implements control requests, for "chapter 9" conformance. 362 Make this be the first driver you try using on top of any new 363 USB peripheral controller driver. Then you can use host-side 364 test software, like the "usbtest" driver, to put your hardware 365 and its driver through a basic set of functional tests. 366 367 config USB_CONFIGFS_F_FS 368 bool "Function filesystem (FunctionFS)" 369 depends on USB_CONFIGFS 370 select USB_F_FS 371 help 372 The Function Filesystem (FunctionFS) lets one create USB 373 composite functions in user space in the same way GadgetFS 374 lets one create USB gadgets in user space. This allows creation 375 of composite gadgets such that some of the functions are 376 implemented in kernel space (for instance Ethernet, serial or 377 mass storage) and other are implemented in user space. 378 379 config USB_CONFIGFS_F_UAC1 380 bool "Audio Class 1.0" 381 depends on USB_CONFIGFS 382 depends on SND 383 select USB_LIBCOMPOSITE 384 select SND_PCM 385 select USB_U_AUDIO 386 select USB_F_UAC1 387 help 388 This Audio function implements 1 AudioControl interface, 389 1 AudioStreaming Interface each for USB-OUT and USB-IN. 390 This driver doesn't expect any real Audio codec to be present 391 on the device - the audio streams are simply sinked to and 392 sourced from a virtual ALSA sound card created. The user-space 393 application may choose to do whatever it wants with the data 394 received from the USB Host and choose to provide whatever it 395 wants as audio data to the USB Host. 396 397 config USB_CONFIGFS_F_UAC1_LEGACY 398 bool "Audio Class 1.0 (legacy implementation)" 399 depends on USB_CONFIGFS 400 depends on SND 401 select USB_LIBCOMPOSITE 402 select SND_PCM 403 select USB_F_UAC1_LEGACY 404 help 405 This Audio function implements 1 AudioControl interface, 406 1 AudioStreaming Interface each for USB-OUT and USB-IN. 407 This is a legacy driver and requires a real Audio codec 408 to be present on the device. 409 410 config USB_CONFIGFS_F_UAC2 411 bool "Audio Class 2.0" 412 depends on USB_CONFIGFS 413 depends on SND 414 select USB_LIBCOMPOSITE 415 select SND_PCM 416 select USB_U_AUDIO 417 select USB_F_UAC2 418 help 419 This Audio function is compatible with USB Audio Class 420 specification 2.0. It implements 1 AudioControl interface, 421 1 AudioStreaming Interface each for USB-OUT and USB-IN. 422 This driver doesn't expect any real Audio codec to be present 423 on the device - the audio streams are simply sinked to and 424 sourced from a virtual ALSA sound card created. The user-space 425 application may choose to do whatever it wants with the data 426 received from the USB Host and choose to provide whatever it 427 wants as audio data to the USB Host. 428 429 config USB_CONFIGFS_F_MIDI 430 bool "MIDI function" 431 depends on USB_CONFIGFS 432 depends on SND 433 select USB_LIBCOMPOSITE 434 select SND_RAWMIDI 435 select USB_F_MIDI 436 help 437 The MIDI Function acts as a USB Audio device, with one MIDI 438 input and one MIDI output. These MIDI jacks appear as 439 a sound "card" in the ALSA sound system. Other MIDI 440 connections can then be made on the gadget system, using 441 ALSA's aconnect utility etc. 442 443 config USB_CONFIGFS_F_MIDI2 444 bool "MIDI 2.0 function" 445 depends on USB_CONFIGFS 446 depends on SND 447 select USB_LIBCOMPOSITE 448 select SND_UMP 449 select SND_UMP_LEGACY_RAWMIDI 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. 457 458 config 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. 467 468 config 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. 480 481 config 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. 494 495 config 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. 508 509 source "drivers/usb/gadget/legacy/Kconfig" 510 511 endif # USB_GADGET 512