xref: /openbmc/linux/drivers/usb/gadget/Kconfig (revision b96fc2f3) 
1#
2# USB Gadget support on a system involves
3#    (a) a peripheral controller, and
4#    (b) the gadget driver using it.
5#
6# NOTE:  Gadget support ** DOES NOT ** depend on host-side CONFIG_USB !!
7#
8#  - Host systems (like PCs) need CONFIG_USB (with "A" jacks).
9#  - Peripherals (like PDAs) need CONFIG_USB_GADGET (with "B" jacks).
10#  - Some systems have both kinds of controllers.
11#
12# With help from a special transceiver and a "Mini-AB" jack, systems with
13# both kinds of controller can also support "USB On-the-Go" (CONFIG_USB_OTG).
14#
15
16menuconfig USB_GADGET
17	tristate "USB Gadget Support"
18	select NLS
19	help
20	   USB is a master/slave protocol, organized with one master
21	   host (such as a PC) controlling up to 127 peripheral devices.
22	   The USB hardware is asymmetric, which makes it easier to set up:
23	   you can't connect a "to-the-host" connector to a peripheral.
24
25	   Linux can run in the host, or in the peripheral.  In both cases
26	   you need a low level bus controller driver, and some software
27	   talking to it.  Peripheral controllers are often discrete silicon,
28	   or are integrated with the CPU in a microcontroller.  The more
29	   familiar host side controllers have names like "EHCI", "OHCI",
30	   or "UHCI", and are usually integrated into southbridges on PC
31	   motherboards.
32
33	   Enable this configuration option if you want to run Linux inside
34	   a USB peripheral device.  Configure one hardware driver for your
35	   peripheral/device side bus controller, and a "gadget driver" for
36	   your peripheral protocol.  (If you use modular gadget drivers,
37	   you may configure more than one.)
38
39	   If in doubt, say "N" and don't enable these drivers; most people
40	   don't have this kind of hardware (except maybe inside Linux PDAs).
41
42	   For more information, see <http://www.linux-usb.org/gadget> and
43	   the kernel DocBook documentation for this API.
44
45if USB_GADGET
46
47config USB_GADGET_DEBUG
48	bool "Debugging messages (DEVELOPMENT)"
49	depends on DEBUG_KERNEL
50	help
51	   Many controller and gadget drivers will print some debugging
52	   messages if you use this option to ask for those messages.
53
54	   Avoid enabling these messages, even if you're actively
55	   debugging such a driver.  Many drivers will emit so many
56	   messages that the driver timings are affected, which will
57	   either create new failure modes or remove the one you're
58	   trying to track down.  Never enable these messages for a
59	   production build.
60
61config USB_GADGET_VERBOSE
62	bool "Verbose debugging Messages (DEVELOPMENT)"
63	depends on USB_GADGET_DEBUG
64	help
65	   Many controller and gadget drivers will print verbose debugging
66	   messages if you use this option to ask for those messages.
67
68	   Avoid enabling these messages, even if you're actively
69	   debugging such a driver.  Many drivers will emit so many
70	   messages that the driver timings are affected, which will
71	   either create new failure modes or remove the one you're
72	   trying to track down.  Never enable these messages for a
73	   production build.
74
75config USB_GADGET_DEBUG_FILES
76	bool "Debugging information files (DEVELOPMENT)"
77	depends on PROC_FS
78	help
79	   Some of the drivers in the "gadget" framework can expose
80	   debugging information in files such as /proc/driver/udc
81	   (for a peripheral controller).  The information in these
82	   files may help when you're troubleshooting or bringing up a
83	   driver on a new board.   Enable these files by choosing "Y"
84	   here.  If in doubt, or to conserve kernel memory, say "N".
85
86config USB_GADGET_DEBUG_FS
87	bool "Debugging information files in debugfs (DEVELOPMENT)"
88	depends on DEBUG_FS
89	help
90	   Some of the drivers in the "gadget" framework can expose
91	   debugging information in files under /sys/kernel/debug/.
92	   The information in these files may help when you're
93	   troubleshooting or bringing up a driver on a new board.
94	   Enable these files by choosing "Y" here.  If in doubt, or
95	   to conserve kernel memory, say "N".
96
97config USB_GADGET_VBUS_DRAW
98	int "Maximum VBUS Power usage (2-500 mA)"
99	range 2 500
100	default 2
101	help
102	   Some devices need to draw power from USB when they are
103	   configured, perhaps to operate circuitry or to recharge
104	   batteries.  This is in addition to any local power supply,
105	   such as an AC adapter or batteries.
106
107	   Enter the maximum power your device draws through USB, in
108	   milliAmperes.  The permitted range of values is 2 - 500 mA;
109	   0 mA would be legal, but can make some hosts misbehave.
110
111	   This value will be used except for system-specific gadget
112	   drivers that have more specific information.
113
114config USB_GADGET_STORAGE_NUM_BUFFERS
115	int "Number of storage pipeline buffers"
116	range 2 4
117	default 2
118	help
119	   Usually 2 buffers are enough to establish a good buffering
120	   pipeline. The number may be increased in order to compensate
121	   for a bursty VFS behaviour. For instance there may be CPU wake up
122	   latencies that makes the VFS to appear bursty in a system with
123	   an CPU on-demand governor. Especially if DMA is doing IO to
124	   offload the CPU. In this case the CPU will go into power
125	   save often and spin up occasionally to move data within VFS.
126	   If selecting USB_GADGET_DEBUG_FILES this value may be set by
127	   a module parameter as well.
128	   If unsure, say 2.
129
130source "drivers/usb/gadget/udc/Kconfig"
131
132#
133# USB Gadget Drivers
134#
135
136# composite based drivers
137config USB_LIBCOMPOSITE
138	tristate
139	select CONFIGFS_FS
140	depends on USB_GADGET
141
142config USB_F_ACM
143	tristate
144
145config USB_F_SS_LB
146	tristate
147
148config USB_U_SERIAL
149	tristate
150
151config USB_U_ETHER
152	tristate
153
154config USB_F_SERIAL
155	tristate
156
157config USB_F_OBEX
158	tristate
159
160config USB_F_NCM
161	tristate
162
163config USB_F_ECM
164	tristate
165
166config USB_F_PHONET
167	tristate
168
169config USB_F_EEM
170	tristate
171
172config USB_F_SUBSET
173	tristate
174
175config USB_F_RNDIS
176	tristate
177
178config USB_F_MASS_STORAGE
179	tristate
180
181config USB_F_FS
182	tristate
183
184config USB_F_UAC1
185	tristate
186
187config USB_F_UAC2
188	tristate
189
190config USB_F_UVC
191	tristate
192
193config USB_F_MIDI
194	tristate
195
196config USB_F_HID
197	tristate
198
199config USB_F_PRINTER
200	tristate
201
202choice
203	tristate "USB Gadget Drivers"
204	default USB_ETH
205	help
206	  A Linux "Gadget Driver" talks to the USB Peripheral Controller
207	  driver through the abstract "gadget" API.  Some other operating
208	  systems call these "client" drivers, of which "class drivers"
209	  are a subset (implementing a USB device class specification).
210	  A gadget driver implements one or more USB functions using
211	  the peripheral hardware.
212
213	  Gadget drivers are hardware-neutral, or "platform independent",
214	  except that they sometimes must understand quirks or limitations
215	  of the particular controllers they work with.  For example, when
216	  a controller doesn't support alternate configurations or provide
217	  enough of the right types of endpoints, the gadget driver might
218	  not be able work with that controller, or might need to implement
219	  a less common variant of a device class protocol.
220
221# this first set of drivers all depend on bulk-capable hardware.
222
223config USB_CONFIGFS
224	tristate "USB functions configurable through configfs"
225	select USB_LIBCOMPOSITE
226	help
227	  A Linux USB "gadget" can be set up through configfs.
228	  If this is the case, the USB functions (which from the host's
229	  perspective are seen as interfaces) and configurations are
230	  specified simply by creating appropriate directories in configfs.
231	  Associating functions with configurations is done by creating
232	  appropriate symbolic links.
233	  For more information see Documentation/usb/gadget_configfs.txt.
234
235config USB_CONFIGFS_SERIAL
236	bool "Generic serial bulk in/out"
237	depends on USB_CONFIGFS
238	depends on TTY
239	select USB_U_SERIAL
240	select USB_F_SERIAL
241	help
242	  The function talks to the Linux-USB generic serial driver.
243
244config USB_CONFIGFS_ACM
245	bool "Abstract Control Model (CDC ACM)"
246	depends on USB_CONFIGFS
247	depends on TTY
248	select USB_U_SERIAL
249	select USB_F_ACM
250	help
251	  ACM serial link.  This function can be used to interoperate with
252	  MS-Windows hosts or with the Linux-USB "cdc-acm" driver.
253
254config USB_CONFIGFS_OBEX
255	bool "Object Exchange Model (CDC OBEX)"
256	depends on USB_CONFIGFS
257	depends on TTY
258	select USB_U_SERIAL
259	select USB_F_OBEX
260	help
261	  You will need a user space OBEX server talking to /dev/ttyGS*,
262	  since the kernel itself doesn't implement the OBEX protocol.
263
264config USB_CONFIGFS_NCM
265	bool "Network Control Model (CDC NCM)"
266	depends on USB_CONFIGFS
267	depends on NET
268	select USB_U_ETHER
269	select USB_F_NCM
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	help
320	  CDC EEM is a newer USB standard that is somewhat simpler than CDC ECM
321	  and therefore can be supported by more hardware.  Technically ECM and
322	  EEM are designed for different applications.  The ECM model extends
323	  the network interface to the target (e.g. a USB cable modem), and the
324	  EEM model is for mobile devices to communicate with hosts using
325	  ethernet over USB.  For Linux gadgets, however, the interface with
326	  the host is the same (a usbX device), so the differences are minimal.
327
328config USB_CONFIGFS_PHONET
329	bool "Phonet protocol"
330	depends on USB_CONFIGFS
331	depends on NET
332	depends on PHONET
333	select USB_U_ETHER
334	select USB_F_PHONET
335	help
336	  The Phonet protocol implementation for USB device.
337
338config USB_CONFIGFS_MASS_STORAGE
339	bool "Mass storage"
340	depends on USB_CONFIGFS
341	depends on BLOCK
342	select USB_F_MASS_STORAGE
343	help
344	  The Mass Storage Gadget acts as a USB Mass Storage disk drive.
345	  As its storage repository it can use a regular file or a block
346	  device (in much the same way as the "loop" device driver),
347	  specified as a module parameter or sysfs option.
348
349config USB_CONFIGFS_F_LB_SS
350	bool "Loopback and sourcesink function (for testing)"
351	depends on USB_CONFIGFS
352	select USB_F_SS_LB
353	help
354	  Loopback function loops back a configurable number of transfers.
355	  Sourcesink function either sinks and sources bulk data.
356	  It also implements control requests, for "chapter 9" conformance.
357	  Make this be the first driver you try using on top of any new
358	  USB peripheral controller driver.  Then you can use host-side
359	  test software, like the "usbtest" driver, to put your hardware
360	  and its driver through a basic set of functional tests.
361
362config USB_CONFIGFS_F_FS
363	bool "Function filesystem (FunctionFS)"
364	depends on USB_CONFIGFS
365	select USB_F_FS
366	help
367	  The Function Filesystem (FunctionFS) lets one create USB
368	  composite functions in user space in the same way GadgetFS
369	  lets one create USB gadgets in user space.  This allows creation
370	  of composite gadgets such that some of the functions are
371	  implemented in kernel space (for instance Ethernet, serial or
372	  mass storage) and other are implemented in user space.
373
374config USB_CONFIGFS_F_UAC1
375	bool "Audio Class 1.0"
376	depends on USB_CONFIGFS
377	depends on SND
378	select USB_LIBCOMPOSITE
379	select SND_PCM
380	select USB_F_UAC1
381	help
382	  This Audio function implements 1 AudioControl interface,
383	  1 AudioStreaming Interface each for USB-OUT and USB-IN.
384	  This driver requires a real Audio codec to be present
385	  on the device.
386
387config USB_CONFIGFS_F_UAC2
388	bool "Audio Class 2.0"
389	depends on USB_CONFIGFS
390	depends on SND
391	select USB_LIBCOMPOSITE
392	select SND_PCM
393	select USB_F_UAC2
394	help
395	  This Audio function is compatible with USB Audio Class
396	  specification 2.0. It implements 1 AudioControl interface,
397	  1 AudioStreaming Interface each for USB-OUT and USB-IN.
398	  This driver doesn't expect any real Audio codec to be present
399	  on the device - the audio streams are simply sinked to and
400	  sourced from a virtual ALSA sound card created. The user-space
401	  application may choose to do whatever it wants with the data
402	  received from the USB Host and choose to provide whatever it
403	  wants as audio data to the USB Host.
404
405config USB_CONFIGFS_F_MIDI
406	bool "MIDI function"
407	depends on USB_CONFIGFS
408	depends on SND
409	select USB_LIBCOMPOSITE
410	select SND_RAWMIDI
411	select USB_F_MIDI
412	help
413	  The MIDI Function acts as a USB Audio device, with one MIDI
414	  input and one MIDI output. These MIDI jacks appear as
415	  a sound "card" in the ALSA sound system. Other MIDI
416	  connections can then be made on the gadget system, using
417	  ALSA's aconnect utility etc.
418
419config USB_CONFIGFS_F_HID
420	bool "HID function"
421	depends on USB_CONFIGFS
422	select USB_F_HID
423	help
424	  The HID function driver provides generic emulation of USB
425	  Human Interface Devices (HID).
426
427	  For more information, see Documentation/usb/gadget_hid.txt.
428
429config USB_CONFIGFS_F_UVC
430	bool "USB Webcam function"
431	depends on USB_CONFIGFS
432	depends on VIDEO_DEV
433	select VIDEOBUF2_VMALLOC
434	select USB_F_UVC
435	help
436	  The Webcam function acts as a composite USB Audio and Video Class
437	  device. It provides a userspace API to process UVC control requests
438	  and stream video data to the host.
439
440config USB_CONFIGFS_F_PRINTER
441	bool "Printer function"
442	select USB_F_PRINTER
443	depends on USB_CONFIGFS
444	help
445	  The Printer function channels data between the USB host and a
446	  userspace program driving the print engine. The user space
447	  program reads and writes the device file /dev/g_printer<X> to
448	  receive or send printer data. It can use ioctl calls to
449	  the device file to get or set printer status.
450
451	  For more information, see Documentation/usb/gadget_printer.txt
452	  which includes sample code for accessing the device file.
453
454source "drivers/usb/gadget/legacy/Kconfig"
455
456endchoice
457
458endif # USB_GADGET
459