xref: /linux/drivers/usb/gadget/Kconfig (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
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
184choice
185	tristate "USB Gadget Drivers"
186	default USB_ETH
187	help
188	  A Linux "Gadget Driver" talks to the USB Peripheral Controller
189	  driver through the abstract "gadget" API.  Some other operating
190	  systems call these "client" drivers, of which "class drivers"
191	  are a subset (implementing a USB device class specification).
192	  A gadget driver implements one or more USB functions using
193	  the peripheral hardware.
194
195	  Gadget drivers are hardware-neutral, or "platform independent",
196	  except that they sometimes must understand quirks or limitations
197	  of the particular controllers they work with.  For example, when
198	  a controller doesn't support alternate configurations or provide
199	  enough of the right types of endpoints, the gadget driver might
200	  not be able work with that controller, or might need to implement
201	  a less common variant of a device class protocol.
202
203# this first set of drivers all depend on bulk-capable hardware.
204
205config USB_CONFIGFS
206	tristate "USB functions configurable through configfs"
207	select USB_LIBCOMPOSITE
208	help
209	  A Linux USB "gadget" can be set up through configfs.
210	  If this is the case, the USB functions (which from the host's
211	  perspective are seen as interfaces) and configurations are
212	  specified simply by creating appropriate directories in configfs.
213	  Associating functions with configurations is done by creating
214	  appropriate symbolic links.
215	  For more information see Documentation/usb/gadget_configfs.txt.
216
217config USB_CONFIGFS_SERIAL
218	boolean "Generic serial bulk in/out"
219	depends on USB_CONFIGFS
220	depends on TTY
221	select USB_U_SERIAL
222	select USB_F_SERIAL
223	help
224	  The function talks to the Linux-USB generic serial driver.
225
226config USB_CONFIGFS_ACM
227	boolean "Abstract Control Model (CDC ACM)"
228	depends on USB_CONFIGFS
229	depends on TTY
230	select USB_U_SERIAL
231	select USB_F_ACM
232	help
233	  ACM serial link.  This function can be used to interoperate with
234	  MS-Windows hosts or with the Linux-USB "cdc-acm" driver.
235
236config USB_CONFIGFS_OBEX
237	boolean "Object Exchange Model (CDC OBEX)"
238	depends on USB_CONFIGFS
239	depends on TTY
240	select USB_U_SERIAL
241	select USB_F_OBEX
242	help
243	  You will need a user space OBEX server talking to /dev/ttyGS*,
244	  since the kernel itself doesn't implement the OBEX protocol.
245
246config USB_CONFIGFS_NCM
247	boolean "Network Control Model (CDC NCM)"
248	depends on USB_CONFIGFS
249	depends on NET
250	select USB_U_ETHER
251	select USB_F_NCM
252	help
253	  NCM is an advanced protocol for Ethernet encapsulation, allows
254	  grouping of several ethernet frames into one USB transfer and
255	  different alignment possibilities.
256
257config USB_CONFIGFS_ECM
258	boolean "Ethernet Control Model (CDC ECM)"
259	depends on USB_CONFIGFS
260	depends on NET
261	select USB_U_ETHER
262	select USB_F_ECM
263	help
264	  The "Communication Device Class" (CDC) Ethernet Control Model.
265	  That protocol is often avoided with pure Ethernet adapters, in
266	  favor of simpler vendor-specific hardware, but is widely
267	  supported by firmware for smart network devices.
268
269config USB_CONFIGFS_ECM_SUBSET
270	boolean "Ethernet Control Model (CDC ECM) subset"
271	depends on USB_CONFIGFS
272	depends on NET
273	select USB_U_ETHER
274	select USB_F_SUBSET
275	help
276	  On hardware that can't implement the full protocol,
277	  a simple CDC subset is used, placing fewer demands on USB.
278
279config USB_CONFIGFS_RNDIS
280	bool "RNDIS"
281	depends on USB_CONFIGFS
282	depends on NET
283	select USB_U_ETHER
284	select USB_F_RNDIS
285	help
286	   Microsoft Windows XP bundles the "Remote NDIS" (RNDIS) protocol,
287	   and Microsoft provides redistributable binary RNDIS drivers for
288	   older versions of Windows.
289
290	   To make MS-Windows work with this, use Documentation/usb/linux.inf
291	   as the "driver info file".  For versions of MS-Windows older than
292	   XP, you'll need to download drivers from Microsoft's website; a URL
293	   is given in comments found in that info file.
294
295config USB_CONFIGFS_EEM
296	bool "Ethernet Emulation Model (EEM)"
297	depends on USB_CONFIGFS
298	depends on NET
299	select USB_U_ETHER
300	select USB_F_EEM
301	help
302	  CDC EEM is a newer USB standard that is somewhat simpler than CDC ECM
303	  and therefore can be supported by more hardware.  Technically ECM and
304	  EEM are designed for different applications.  The ECM model extends
305	  the network interface to the target (e.g. a USB cable modem), and the
306	  EEM model is for mobile devices to communicate with hosts using
307	  ethernet over USB.  For Linux gadgets, however, the interface with
308	  the host is the same (a usbX device), so the differences are minimal.
309
310config USB_CONFIGFS_PHONET
311	boolean "Phonet protocol"
312	depends on USB_CONFIGFS
313	depends on NET
314	depends on PHONET
315	select USB_U_ETHER
316	select USB_F_PHONET
317	help
318	  The Phonet protocol implementation for USB device.
319
320config USB_CONFIGFS_MASS_STORAGE
321	boolean "Mass storage"
322	depends on USB_CONFIGFS
323	depends on BLOCK
324	select USB_F_MASS_STORAGE
325	help
326	  The Mass Storage Gadget acts as a USB Mass Storage disk drive.
327	  As its storage repository it can use a regular file or a block
328	  device (in much the same way as the "loop" device driver),
329	  specified as a module parameter or sysfs option.
330
331config USB_CONFIGFS_F_LB_SS
332	boolean "Loopback and sourcesink function (for testing)"
333	depends on USB_CONFIGFS
334	select USB_F_SS_LB
335	help
336	  Loopback function loops back a configurable number of transfers.
337	  Sourcesink function either sinks and sources bulk data.
338	  It also implements control requests, for "chapter 9" conformance.
339	  Make this be the first driver you try using on top of any new
340	  USB peripheral controller driver.  Then you can use host-side
341	  test software, like the "usbtest" driver, to put your hardware
342	  and its driver through a basic set of functional tests.
343
344config USB_CONFIGFS_F_FS
345	boolean "Function filesystem (FunctionFS)"
346	depends on USB_CONFIGFS
347	select USB_F_FS
348	help
349	  The Function Filesystem (FunctionFS) lets one create USB
350	  composite functions in user space in the same way GadgetFS
351	  lets one create USB gadgets in user space.  This allows creation
352	  of composite gadgets such that some of the functions are
353	  implemented in kernel space (for instance Ethernet, serial or
354	  mass storage) and other are implemented in user space.
355
356source "drivers/usb/gadget/legacy/Kconfig"
357
358endchoice
359
360endif # USB_GADGET
361