Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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