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
215config USB_F_HID
216	tristate
217
218config USB_F_PRINTER
219	tristate
220
221config USB_F_TCM
222	tristate
223
224# this first set of drivers all depend on bulk-capable hardware.
225
226config 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
238config 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
247config 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
257config 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
267config 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
279config 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
291config 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
301config 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
317config 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
333config 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
343config 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
354config 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
367config 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
379config 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
397config 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
410config 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
429config 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
443config 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
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