xref: /openbmc/linux/drivers/usb/gadget/Kconfig (revision b85e9de9)
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	boolean "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	boolean "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	boolean "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
196choice
197	tristate "USB Gadget Drivers"
198	default USB_ETH
199	help
200	  A Linux "Gadget Driver" talks to the USB Peripheral Controller
201	  driver through the abstract "gadget" API.  Some other operating
202	  systems call these "client" drivers, of which "class drivers"
203	  are a subset (implementing a USB device class specification).
204	  A gadget driver implements one or more USB functions using
205	  the peripheral hardware.
206
207	  Gadget drivers are hardware-neutral, or "platform independent",
208	  except that they sometimes must understand quirks or limitations
209	  of the particular controllers they work with.  For example, when
210	  a controller doesn't support alternate configurations or provide
211	  enough of the right types of endpoints, the gadget driver might
212	  not be able work with that controller, or might need to implement
213	  a less common variant of a device class protocol.
214
215# this first set of drivers all depend on bulk-capable hardware.
216
217config USB_CONFIGFS
218	tristate "USB functions configurable through configfs"
219	select USB_LIBCOMPOSITE
220	help
221	  A Linux USB "gadget" can be set up through configfs.
222	  If this is the case, the USB functions (which from the host's
223	  perspective are seen as interfaces) and configurations are
224	  specified simply by creating appropriate directories in configfs.
225	  Associating functions with configurations is done by creating
226	  appropriate symbolic links.
227	  For more information see Documentation/usb/gadget_configfs.txt.
228
229config USB_CONFIGFS_SERIAL
230	boolean "Generic serial bulk in/out"
231	depends on USB_CONFIGFS
232	depends on TTY
233	select USB_U_SERIAL
234	select USB_F_SERIAL
235	help
236	  The function talks to the Linux-USB generic serial driver.
237
238config USB_CONFIGFS_ACM
239	boolean "Abstract Control Model (CDC ACM)"
240	depends on USB_CONFIGFS
241	depends on TTY
242	select USB_U_SERIAL
243	select USB_F_ACM
244	help
245	  ACM serial link.  This function can be used to interoperate with
246	  MS-Windows hosts or with the Linux-USB "cdc-acm" driver.
247
248config USB_CONFIGFS_OBEX
249	boolean "Object Exchange Model (CDC OBEX)"
250	depends on USB_CONFIGFS
251	depends on TTY
252	select USB_U_SERIAL
253	select USB_F_OBEX
254	help
255	  You will need a user space OBEX server talking to /dev/ttyGS*,
256	  since the kernel itself doesn't implement the OBEX protocol.
257
258config USB_CONFIGFS_NCM
259	boolean "Network Control Model (CDC NCM)"
260	depends on USB_CONFIGFS
261	depends on NET
262	select USB_U_ETHER
263	select USB_F_NCM
264	help
265	  NCM is an advanced protocol for Ethernet encapsulation, allows
266	  grouping of several ethernet frames into one USB transfer and
267	  different alignment possibilities.
268
269config USB_CONFIGFS_ECM
270	boolean "Ethernet Control Model (CDC ECM)"
271	depends on USB_CONFIGFS
272	depends on NET
273	select USB_U_ETHER
274	select USB_F_ECM
275	help
276	  The "Communication Device Class" (CDC) Ethernet Control Model.
277	  That protocol is often avoided with pure Ethernet adapters, in
278	  favor of simpler vendor-specific hardware, but is widely
279	  supported by firmware for smart network devices.
280
281config USB_CONFIGFS_ECM_SUBSET
282	boolean "Ethernet Control Model (CDC ECM) subset"
283	depends on USB_CONFIGFS
284	depends on NET
285	select USB_U_ETHER
286	select USB_F_SUBSET
287	help
288	  On hardware that can't implement the full protocol,
289	  a simple CDC subset is used, placing fewer demands on USB.
290
291config USB_CONFIGFS_RNDIS
292	bool "RNDIS"
293	depends on USB_CONFIGFS
294	depends on NET
295	select USB_U_ETHER
296	select USB_F_RNDIS
297	help
298	   Microsoft Windows XP bundles the "Remote NDIS" (RNDIS) protocol,
299	   and Microsoft provides redistributable binary RNDIS drivers for
300	   older versions of Windows.
301
302	   To make MS-Windows work with this, use Documentation/usb/linux.inf
303	   as the "driver info file".  For versions of MS-Windows older than
304	   XP, you'll need to download drivers from Microsoft's website; a URL
305	   is given in comments found in that info file.
306
307config USB_CONFIGFS_EEM
308	bool "Ethernet Emulation Model (EEM)"
309	depends on USB_CONFIGFS
310	depends on NET
311	select USB_U_ETHER
312	select USB_F_EEM
313	help
314	  CDC EEM is a newer USB standard that is somewhat simpler than CDC ECM
315	  and therefore can be supported by more hardware.  Technically ECM and
316	  EEM are designed for different applications.  The ECM model extends
317	  the network interface to the target (e.g. a USB cable modem), and the
318	  EEM model is for mobile devices to communicate with hosts using
319	  ethernet over USB.  For Linux gadgets, however, the interface with
320	  the host is the same (a usbX device), so the differences are minimal.
321
322config USB_CONFIGFS_PHONET
323	boolean "Phonet protocol"
324	depends on USB_CONFIGFS
325	depends on NET
326	depends on PHONET
327	select USB_U_ETHER
328	select USB_F_PHONET
329	help
330	  The Phonet protocol implementation for USB device.
331
332config USB_CONFIGFS_MASS_STORAGE
333	boolean "Mass storage"
334	depends on USB_CONFIGFS
335	depends on BLOCK
336	select USB_F_MASS_STORAGE
337	help
338	  The Mass Storage Gadget acts as a USB Mass Storage disk drive.
339	  As its storage repository it can use a regular file or a block
340	  device (in much the same way as the "loop" device driver),
341	  specified as a module parameter or sysfs option.
342
343config USB_CONFIGFS_F_LB_SS
344	boolean "Loopback and sourcesink function (for testing)"
345	depends on USB_CONFIGFS
346	select USB_F_SS_LB
347	help
348	  Loopback function loops back a configurable number of transfers.
349	  Sourcesink function either sinks and sources bulk data.
350	  It also implements control requests, for "chapter 9" conformance.
351	  Make this be the first driver you try using on top of any new
352	  USB peripheral controller driver.  Then you can use host-side
353	  test software, like the "usbtest" driver, to put your hardware
354	  and its driver through a basic set of functional tests.
355
356config USB_CONFIGFS_F_FS
357	boolean "Function filesystem (FunctionFS)"
358	depends on USB_CONFIGFS
359	select USB_F_FS
360	help
361	  The Function Filesystem (FunctionFS) lets one create USB
362	  composite functions in user space in the same way GadgetFS
363	  lets one create USB gadgets in user space.  This allows creation
364	  of composite gadgets such that some of the functions are
365	  implemented in kernel space (for instance Ethernet, serial or
366	  mass storage) and other are implemented in user space.
367
368config USB_CONFIGFS_F_UAC1
369	boolean "Audio Class 1.0"
370	depends on USB_CONFIGFS
371	depends on SND
372	select USB_LIBCOMPOSITE
373	select SND_PCM
374	select USB_F_UAC1
375	help
376	  This Audio function implements 1 AudioControl interface,
377	  1 AudioStreaming Interface each for USB-OUT and USB-IN.
378	  This driver requires a real Audio codec to be present
379	  on the device.
380
381config USB_CONFIGFS_F_UAC2
382	boolean "Audio Class 2.0"
383	depends on USB_CONFIGFS
384	depends on SND
385	select USB_LIBCOMPOSITE
386	select SND_PCM
387	select USB_F_UAC2
388	help
389	  This Audio function is compatible with USB Audio Class
390	  specification 2.0. It implements 1 AudioControl interface,
391	  1 AudioStreaming Interface each for USB-OUT and USB-IN.
392	  This driver doesn't expect any real Audio codec to be present
393	  on the device - the audio streams are simply sinked to and
394	  sourced from a virtual ALSA sound card created. The user-space
395	  application may choose to do whatever it wants with the data
396	  received from the USB Host and choose to provide whatever it
397	  wants as audio data to the USB Host.
398
399source "drivers/usb/gadget/legacy/Kconfig"
400
401endchoice
402
403endif # USB_GADGET
404