xref: /openbmc/linux/drivers/usb/gadget/Kconfig (revision a44e4f3a) 
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 master/slave protocol, organized with one master
23	   host (such as a 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
207config USB_F_MIDI
208	tristate
209
210config USB_F_HID
211	tristate
212
213config USB_F_PRINTER
214	tristate
215
216config USB_F_TCM
217	tristate
218
219# this first set of drivers all depend on bulk-capable hardware.
220
221config USB_CONFIGFS
222	tristate "USB Gadget functions configurable through configfs"
223	select USB_LIBCOMPOSITE
224	help
225	  A Linux USB "gadget" can be set up through configfs.
226	  If this is the case, the USB functions (which from the host's
227	  perspective are seen as interfaces) and configurations are
228	  specified simply by creating appropriate directories in configfs.
229	  Associating functions with configurations is done by creating
230	  appropriate symbolic links.
231	  For more information see Documentation/usb/gadget_configfs.rst.
232
233config USB_CONFIGFS_SERIAL
234	bool "Generic serial bulk in/out"
235	depends on USB_CONFIGFS
236	depends on TTY
237	select USB_U_SERIAL
238	select USB_F_SERIAL
239	help
240	  The function talks to the Linux-USB generic serial driver.
241
242config USB_CONFIGFS_ACM
243	bool "Abstract Control Model (CDC ACM)"
244	depends on USB_CONFIGFS
245	depends on TTY
246	select USB_U_SERIAL
247	select USB_F_ACM
248	help
249	  ACM serial link.  This function can be used to interoperate with
250	  MS-Windows hosts or with the Linux-USB "cdc-acm" driver.
251
252config USB_CONFIGFS_OBEX
253	bool "Object Exchange Model (CDC OBEX)"
254	depends on USB_CONFIGFS
255	depends on TTY
256	select USB_U_SERIAL
257	select USB_F_OBEX
258	help
259	  You will need a user space OBEX server talking to /dev/ttyGS*,
260	  since the kernel itself doesn't implement the OBEX protocol.
261
262config USB_CONFIGFS_NCM
263	bool "Network Control Model (CDC NCM)"
264	depends on USB_CONFIGFS
265	depends on NET
266	select USB_U_ETHER
267	select USB_F_NCM
268	help
269	  NCM is an advanced protocol for Ethernet encapsulation, allows
270	  grouping of several ethernet frames into one USB transfer and
271	  different alignment possibilities.
272
273config USB_CONFIGFS_ECM
274	bool "Ethernet Control Model (CDC ECM)"
275	depends on USB_CONFIGFS
276	depends on NET
277	select USB_U_ETHER
278	select USB_F_ECM
279	help
280	  The "Communication Device Class" (CDC) Ethernet Control Model.
281	  That protocol is often avoided with pure Ethernet adapters, in
282	  favor of simpler vendor-specific hardware, but is widely
283	  supported by firmware for smart network devices.
284
285config USB_CONFIGFS_ECM_SUBSET
286	bool "Ethernet Control Model (CDC ECM) subset"
287	depends on USB_CONFIGFS
288	depends on NET
289	select USB_U_ETHER
290	select USB_F_SUBSET
291	help
292	  On hardware that can't implement the full protocol,
293	  a simple CDC subset is used, placing fewer demands on USB.
294
295config USB_CONFIGFS_RNDIS
296	bool "RNDIS"
297	depends on USB_CONFIGFS
298	depends on NET
299	select USB_U_ETHER
300	select USB_F_RNDIS
301	help
302	   Microsoft Windows XP bundles the "Remote NDIS" (RNDIS) protocol,
303	   and Microsoft provides redistributable binary RNDIS drivers for
304	   older versions of Windows.
305
306	   To make MS-Windows work with this, use Documentation/usb/linux.inf
307	   as the "driver info file".  For versions of MS-Windows older than
308	   XP, you'll need to download drivers from Microsoft's website; a URL
309	   is given in comments found in that info file.
310
311config USB_CONFIGFS_EEM
312	bool "Ethernet Emulation Model (EEM)"
313	depends on USB_CONFIGFS
314	depends on NET
315	select USB_U_ETHER
316	select USB_F_EEM
317	help
318	  CDC EEM is a newer USB standard that is somewhat simpler than CDC ECM
319	  and therefore can be supported by more hardware.  Technically ECM and
320	  EEM are designed for different applications.  The ECM model extends
321	  the network interface to the target (e.g. a USB cable modem), and the
322	  EEM model is for mobile devices to communicate with hosts using
323	  ethernet over USB.  For Linux gadgets, however, the interface with
324	  the host is the same (a usbX device), so the differences are minimal.
325
326config USB_CONFIGFS_PHONET
327	bool "Phonet protocol"
328	depends on USB_CONFIGFS
329	depends on NET
330	depends on PHONET
331	select USB_U_ETHER
332	select USB_F_PHONET
333	help
334	  The Phonet protocol implementation for USB device.
335
336config USB_CONFIGFS_MASS_STORAGE
337	bool "Mass storage"
338	depends on USB_CONFIGFS
339	depends on BLOCK
340	select USB_F_MASS_STORAGE
341	help
342	  The Mass Storage Gadget acts as a USB Mass Storage disk drive.
343	  As its storage repository it can use a regular file or a block
344	  device (in much the same way as the "loop" device driver),
345	  specified as a module parameter or sysfs option.
346
347config USB_CONFIGFS_F_LB_SS
348	bool "Loopback and sourcesink function (for testing)"
349	depends on USB_CONFIGFS
350	select USB_F_SS_LB
351	help
352	  Loopback function loops back a configurable number of transfers.
353	  Sourcesink function either sinks and sources bulk data.
354	  It also implements control requests, for "chapter 9" conformance.
355	  Make this be the first driver you try using on top of any new
356	  USB peripheral controller driver.  Then you can use host-side
357	  test software, like the "usbtest" driver, to put your hardware
358	  and its driver through a basic set of functional tests.
359
360config USB_CONFIGFS_F_FS
361	bool "Function filesystem (FunctionFS)"
362	depends on USB_CONFIGFS
363	select USB_F_FS
364	help
365	  The Function Filesystem (FunctionFS) lets one create USB
366	  composite functions in user space in the same way GadgetFS
367	  lets one create USB gadgets in user space.  This allows creation
368	  of composite gadgets such that some of the functions are
369	  implemented in kernel space (for instance Ethernet, serial or
370	  mass storage) and other are implemented in user space.
371
372config USB_CONFIGFS_F_UAC1
373	bool "Audio Class 1.0"
374	depends on USB_CONFIGFS
375	depends on SND
376	select USB_LIBCOMPOSITE
377	select SND_PCM
378	select USB_U_AUDIO
379	select USB_F_UAC1
380	help
381	  This Audio function implements 1 AudioControl interface,
382	  1 AudioStreaming Interface each for USB-OUT and USB-IN.
383	  This driver doesn't expect any real Audio codec to be present
384	  on the device - the audio streams are simply sinked to and
385	  sourced from a virtual ALSA sound card created. The user-space
386	  application may choose to do whatever it wants with the data
387	  received from the USB Host and choose to provide whatever it
388	  wants as audio data to the USB Host.
389
390config USB_CONFIGFS_F_UAC1_LEGACY
391	bool "Audio Class 1.0 (legacy implementation)"
392	depends on USB_CONFIGFS
393	depends on SND
394	select USB_LIBCOMPOSITE
395	select SND_PCM
396	select USB_F_UAC1_LEGACY
397	help
398	  This Audio function implements 1 AudioControl interface,
399	  1 AudioStreaming Interface each for USB-OUT and USB-IN.
400	  This is a legacy driver and requires a real Audio codec
401	  to be present on the device.
402
403config USB_CONFIGFS_F_UAC2
404	bool "Audio Class 2.0"
405	depends on USB_CONFIGFS
406	depends on SND
407	select USB_LIBCOMPOSITE
408	select SND_PCM
409	select USB_U_AUDIO
410	select USB_F_UAC2
411	help
412	  This Audio function is compatible with USB Audio Class
413	  specification 2.0. It implements 1 AudioControl interface,
414	  1 AudioStreaming Interface each for USB-OUT and USB-IN.
415	  This driver doesn't expect any real Audio codec to be present
416	  on the device - the audio streams are simply sinked to and
417	  sourced from a virtual ALSA sound card created. The user-space
418	  application may choose to do whatever it wants with the data
419	  received from the USB Host and choose to provide whatever it
420	  wants as audio data to the USB Host.
421
422config USB_CONFIGFS_F_MIDI
423	bool "MIDI function"
424	depends on USB_CONFIGFS
425	depends on SND
426	select USB_LIBCOMPOSITE
427	select SND_RAWMIDI
428	select USB_F_MIDI
429	help
430	  The MIDI Function acts as a USB Audio device, with one MIDI
431	  input and one MIDI output. These MIDI jacks appear as
432	  a sound "card" in the ALSA sound system. Other MIDI
433	  connections can then be made on the gadget system, using
434	  ALSA's aconnect utility etc.
435
436config USB_CONFIGFS_F_HID
437	bool "HID function"
438	depends on USB_CONFIGFS
439	select USB_F_HID
440	help
441	  The HID function driver provides generic emulation of USB
442	  Human Interface Devices (HID).
443
444	  For more information, see Documentation/usb/gadget_hid.rst.
445
446config USB_CONFIGFS_F_UVC
447	bool "USB Webcam function"
448	depends on USB_CONFIGFS
449	depends on VIDEO_V4L2
450	depends on VIDEO_DEV
451	select VIDEOBUF2_VMALLOC
452	select USB_F_UVC
453	help
454	  The Webcam function acts as a composite USB Audio and Video Class
455	  device. It provides a userspace API to process UVC control requests
456	  and stream video data to the host.
457
458config USB_CONFIGFS_F_PRINTER
459	bool "Printer function"
460	select USB_F_PRINTER
461	depends on USB_CONFIGFS
462	help
463	  The Printer function channels data between the USB host and a
464	  userspace program driving the print engine. The user space
465	  program reads and writes the device file /dev/g_printer<X> to
466	  receive or send printer data. It can use ioctl calls to
467	  the device file to get or set printer status.
468
469	  For more information, see Documentation/usb/gadget_printer.rst
470	  which includes sample code for accessing the device file.
471
472config USB_CONFIGFS_F_TCM
473	bool "USB Gadget Target Fabric"
474	depends on TARGET_CORE
475	depends on USB_CONFIGFS
476	select USB_LIBCOMPOSITE
477	select USB_F_TCM
478	help
479	  This fabric is a USB gadget component. Two USB protocols are
480	  supported that is BBB or BOT (Bulk Only Transport) and UAS
481	  (USB Attached SCSI). BOT is advertised on alternative
482	  interface 0 (primary) and UAS is on alternative interface 1.
483	  Both protocols can work on USB2.0 and USB3.0.
484	  UAS utilizes the USB 3.0 feature called streams support.
485
486choice
487	tristate "USB Gadget precomposed configurations"
488	default USB_ETH
489	optional
490	help
491	  A Linux "Gadget Driver" talks to the USB Peripheral Controller
492	  driver through the abstract "gadget" API.  Some other operating
493	  systems call these "client" drivers, of which "class drivers"
494	  are a subset (implementing a USB device class specification).
495	  A gadget driver implements one or more USB functions using
496	  the peripheral hardware.
497
498	  Gadget drivers are hardware-neutral, or "platform independent",
499	  except that they sometimes must understand quirks or limitations
500	  of the particular controllers they work with.  For example, when
501	  a controller doesn't support alternate configurations or provide
502	  enough of the right types of endpoints, the gadget driver might
503	  not be able work with that controller, or might need to implement
504	  a less common variant of a device class protocol.
505
506	  The available choices each represent a single precomposed USB
507	  gadget configuration. In the device model, each option contains
508	  both the device instantiation as a child for a USB gadget
509	  controller, and the relevant drivers for each function declared
510	  by the device.
511
512source "drivers/usb/gadget/legacy/Kconfig"
513
514endchoice
515
516endif # USB_GADGET
517