2 # USB Gadget support on a system involves
3 # (a) a peripheral controller, and
4 # (b) the gadget driver using it.
6 # NOTE: Gadget support ** DOES NOT ** depend on host-side CONFIG_USB !!
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.
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).
17 tristate "USB Gadget Support"
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.
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
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.)
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).
42 For more information, see <http://www.linux-usb.org/gadget> and
43 the kernel DocBook documentation for this API.
47 config USB_GADGET_DEBUG
48 bool "Debugging messages (DEVELOPMENT)"
49 depends on DEBUG_KERNEL
51 Many controller and gadget drivers will print some debugging
52 messages if you use this option to ask for those messages.
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
61 config USB_GADGET_VERBOSE
62 bool "Verbose debugging Messages (DEVELOPMENT)"
63 depends on USB_GADGET_DEBUG
65 Many controller and gadget drivers will print verbose debugging
66 messages if you use this option to ask for those messages.
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
75 config USB_GADGET_DEBUG_FILES
76 bool "Debugging information files (DEVELOPMENT)"
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".
86 config USB_GADGET_DEBUG_FS
87 bool "Debugging information files in debugfs (DEVELOPMENT)"
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".
97 config USB_GADGET_VBUS_DRAW
98 int "Maximum VBUS Power usage (2-500 mA)"
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.
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.
111 This value will be used except for system-specific gadget
112 drivers that have more specific information.
114 config USB_GADGET_STORAGE_NUM_BUFFERS
115 int "Number of storage pipeline buffers"
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.
130 source "drivers/usb/gadget/udc/Kconfig"
136 # composite based drivers
137 config USB_LIBCOMPOSITE
140 depends on USB_GADGET
178 config USB_F_MASS_STORAGE
200 tristate "USB Gadget Drivers"
203 A Linux "Gadget Driver" talks to the USB Peripheral Controller
204 driver through the abstract "gadget" API. Some other operating
205 systems call these "client" drivers, of which "class drivers"
206 are a subset (implementing a USB device class specification).
207 A gadget driver implements one or more USB functions using
208 the peripheral hardware.
210 Gadget drivers are hardware-neutral, or "platform independent",
211 except that they sometimes must understand quirks or limitations
212 of the particular controllers they work with. For example, when
213 a controller doesn't support alternate configurations or provide
214 enough of the right types of endpoints, the gadget driver might
215 not be able work with that controller, or might need to implement
216 a less common variant of a device class protocol.
218 # this first set of drivers all depend on bulk-capable hardware.
221 tristate "USB functions configurable through configfs"
222 select USB_LIBCOMPOSITE
224 A Linux USB "gadget" can be set up through configfs.
225 If this is the case, the USB functions (which from the host's
226 perspective are seen as interfaces) and configurations are
227 specified simply by creating appropriate directories in configfs.
228 Associating functions with configurations is done by creating
229 appropriate symbolic links.
230 For more information see Documentation/usb/gadget_configfs.txt.
232 config USB_CONFIGFS_SERIAL
233 bool "Generic serial bulk in/out"
234 depends on USB_CONFIGFS
239 The function talks to the Linux-USB generic serial driver.
241 config USB_CONFIGFS_ACM
242 bool "Abstract Control Model (CDC ACM)"
243 depends on USB_CONFIGFS
248 ACM serial link. This function can be used to interoperate with
249 MS-Windows hosts or with the Linux-USB "cdc-acm" driver.
251 config USB_CONFIGFS_OBEX
252 bool "Object Exchange Model (CDC OBEX)"
253 depends on USB_CONFIGFS
258 You will need a user space OBEX server talking to /dev/ttyGS*,
259 since the kernel itself doesn't implement the OBEX protocol.
261 config USB_CONFIGFS_NCM
262 bool "Network Control Model (CDC NCM)"
263 depends on USB_CONFIGFS
268 NCM is an advanced protocol for Ethernet encapsulation, allows
269 grouping of several ethernet frames into one USB transfer and
270 different alignment possibilities.
272 config USB_CONFIGFS_ECM
273 bool "Ethernet Control Model (CDC ECM)"
274 depends on USB_CONFIGFS
279 The "Communication Device Class" (CDC) Ethernet Control Model.
280 That protocol is often avoided with pure Ethernet adapters, in
281 favor of simpler vendor-specific hardware, but is widely
282 supported by firmware for smart network devices.
284 config USB_CONFIGFS_ECM_SUBSET
285 bool "Ethernet Control Model (CDC ECM) subset"
286 depends on USB_CONFIGFS
291 On hardware that can't implement the full protocol,
292 a simple CDC subset is used, placing fewer demands on USB.
294 config USB_CONFIGFS_RNDIS
296 depends on USB_CONFIGFS
301 Microsoft Windows XP bundles the "Remote NDIS" (RNDIS) protocol,
302 and Microsoft provides redistributable binary RNDIS drivers for
303 older versions of Windows.
305 To make MS-Windows work with this, use Documentation/usb/linux.inf
306 as the "driver info file". For versions of MS-Windows older than
307 XP, you'll need to download drivers from Microsoft's website; a URL
308 is given in comments found in that info file.
310 config USB_CONFIGFS_EEM
311 bool "Ethernet Emulation Model (EEM)"
312 depends on USB_CONFIGFS
317 CDC EEM is a newer USB standard that is somewhat simpler than CDC ECM
318 and therefore can be supported by more hardware. Technically ECM and
319 EEM are designed for different applications. The ECM model extends
320 the network interface to the target (e.g. a USB cable modem), and the
321 EEM model is for mobile devices to communicate with hosts using
322 ethernet over USB. For Linux gadgets, however, the interface with
323 the host is the same (a usbX device), so the differences are minimal.
325 config USB_CONFIGFS_PHONET
326 bool "Phonet protocol"
327 depends on USB_CONFIGFS
333 The Phonet protocol implementation for USB device.
335 config USB_CONFIGFS_MASS_STORAGE
337 depends on USB_CONFIGFS
339 select USB_F_MASS_STORAGE
341 The Mass Storage Gadget acts as a USB Mass Storage disk drive.
342 As its storage repository it can use a regular file or a block
343 device (in much the same way as the "loop" device driver),
344 specified as a module parameter or sysfs option.
346 config USB_CONFIGFS_F_LB_SS
347 bool "Loopback and sourcesink function (for testing)"
348 depends on USB_CONFIGFS
351 Loopback function loops back a configurable number of transfers.
352 Sourcesink function either sinks and sources bulk data.
353 It also implements control requests, for "chapter 9" conformance.
354 Make this be the first driver you try using on top of any new
355 USB peripheral controller driver. Then you can use host-side
356 test software, like the "usbtest" driver, to put your hardware
357 and its driver through a basic set of functional tests.
359 config USB_CONFIGFS_F_FS
360 bool "Function filesystem (FunctionFS)"
361 depends on USB_CONFIGFS
364 The Function Filesystem (FunctionFS) lets one create USB
365 composite functions in user space in the same way GadgetFS
366 lets one create USB gadgets in user space. This allows creation
367 of composite gadgets such that some of the functions are
368 implemented in kernel space (for instance Ethernet, serial or
369 mass storage) and other are implemented in user space.
371 config USB_CONFIGFS_F_UAC1
372 bool "Audio Class 1.0"
373 depends on USB_CONFIGFS
375 select USB_LIBCOMPOSITE
379 This Audio function implements 1 AudioControl interface,
380 1 AudioStreaming Interface each for USB-OUT and USB-IN.
381 This driver requires a real Audio codec to be present
384 config USB_CONFIGFS_F_UAC2
385 bool "Audio Class 2.0"
386 depends on USB_CONFIGFS
388 select USB_LIBCOMPOSITE
392 This Audio function is compatible with USB Audio Class
393 specification 2.0. It implements 1 AudioControl interface,
394 1 AudioStreaming Interface each for USB-OUT and USB-IN.
395 This driver doesn't expect any real Audio codec to be present
396 on the device - the audio streams are simply sinked to and
397 sourced from a virtual ALSA sound card created. The user-space
398 application may choose to do whatever it wants with the data
399 received from the USB Host and choose to provide whatever it
400 wants as audio data to the USB Host.
402 config USB_CONFIGFS_F_MIDI
404 depends on USB_CONFIGFS
406 select USB_LIBCOMPOSITE
410 The MIDI Function acts as a USB Audio device, with one MIDI
411 input and one MIDI output. These MIDI jacks appear as
412 a sound "card" in the ALSA sound system. Other MIDI
413 connections can then be made on the gadget system, using
414 ALSA's aconnect utility etc.
416 config USB_CONFIGFS_F_HID
418 depends on USB_CONFIGFS
421 The HID function driver provides generic emulation of USB
422 Human Interface Devices (HID).
424 For more information, see Documentation/usb/gadget_hid.txt.
426 config USB_CONFIGFS_F_UVC
427 bool "USB Webcam function"
428 depends on USB_CONFIGFS
430 select VIDEOBUF2_VMALLOC
433 The Webcam function acts as a composite USB Audio and Video Class
434 device. It provides a userspace API to process UVC control requests
435 and stream video data to the host.
437 source "drivers/usb/gadget/legacy/Kconfig"