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
209 tristate "USB Gadget Drivers"
212 A Linux "Gadget Driver" talks to the USB Peripheral Controller
213 driver through the abstract "gadget" API. Some other operating
214 systems call these "client" drivers, of which "class drivers"
215 are a subset (implementing a USB device class specification).
216 A gadget driver implements one or more USB functions using
217 the peripheral hardware.
219 Gadget drivers are hardware-neutral, or "platform independent",
220 except that they sometimes must understand quirks or limitations
221 of the particular controllers they work with. For example, when
222 a controller doesn't support alternate configurations or provide
223 enough of the right types of endpoints, the gadget driver might
224 not be able work with that controller, or might need to implement
225 a less common variant of a device class protocol.
227 # this first set of drivers all depend on bulk-capable hardware.
230 tristate "USB functions configurable through configfs"
231 select USB_LIBCOMPOSITE
233 A Linux USB "gadget" can be set up through configfs.
234 If this is the case, the USB functions (which from the host's
235 perspective are seen as interfaces) and configurations are
236 specified simply by creating appropriate directories in configfs.
237 Associating functions with configurations is done by creating
238 appropriate symbolic links.
239 For more information see Documentation/usb/gadget_configfs.txt.
241 config USB_CONFIGFS_SERIAL
242 bool "Generic serial bulk in/out"
243 depends on USB_CONFIGFS
248 The function talks to the Linux-USB generic serial driver.
250 config USB_CONFIGFS_ACM
251 bool "Abstract Control Model (CDC ACM)"
252 depends on USB_CONFIGFS
257 ACM serial link. This function can be used to interoperate with
258 MS-Windows hosts or with the Linux-USB "cdc-acm" driver.
260 config USB_CONFIGFS_OBEX
261 bool "Object Exchange Model (CDC OBEX)"
262 depends on USB_CONFIGFS
267 You will need a user space OBEX server talking to /dev/ttyGS*,
268 since the kernel itself doesn't implement the OBEX protocol.
270 config USB_CONFIGFS_NCM
271 bool "Network Control Model (CDC NCM)"
272 depends on USB_CONFIGFS
277 NCM is an advanced protocol for Ethernet encapsulation, allows
278 grouping of several ethernet frames into one USB transfer and
279 different alignment possibilities.
281 config USB_CONFIGFS_ECM
282 bool "Ethernet Control Model (CDC ECM)"
283 depends on USB_CONFIGFS
288 The "Communication Device Class" (CDC) Ethernet Control Model.
289 That protocol is often avoided with pure Ethernet adapters, in
290 favor of simpler vendor-specific hardware, but is widely
291 supported by firmware for smart network devices.
293 config USB_CONFIGFS_ECM_SUBSET
294 bool "Ethernet Control Model (CDC ECM) subset"
295 depends on USB_CONFIGFS
300 On hardware that can't implement the full protocol,
301 a simple CDC subset is used, placing fewer demands on USB.
303 config USB_CONFIGFS_RNDIS
305 depends on USB_CONFIGFS
310 Microsoft Windows XP bundles the "Remote NDIS" (RNDIS) protocol,
311 and Microsoft provides redistributable binary RNDIS drivers for
312 older versions of Windows.
314 To make MS-Windows work with this, use Documentation/usb/linux.inf
315 as the "driver info file". For versions of MS-Windows older than
316 XP, you'll need to download drivers from Microsoft's website; a URL
317 is given in comments found in that info file.
319 config USB_CONFIGFS_EEM
320 bool "Ethernet Emulation Model (EEM)"
321 depends on USB_CONFIGFS
326 CDC EEM is a newer USB standard that is somewhat simpler than CDC ECM
327 and therefore can be supported by more hardware. Technically ECM and
328 EEM are designed for different applications. The ECM model extends
329 the network interface to the target (e.g. a USB cable modem), and the
330 EEM model is for mobile devices to communicate with hosts using
331 ethernet over USB. For Linux gadgets, however, the interface with
332 the host is the same (a usbX device), so the differences are minimal.
334 config USB_CONFIGFS_PHONET
335 bool "Phonet protocol"
336 depends on USB_CONFIGFS
342 The Phonet protocol implementation for USB device.
344 config USB_CONFIGFS_MASS_STORAGE
346 depends on USB_CONFIGFS
348 select USB_F_MASS_STORAGE
350 The Mass Storage Gadget acts as a USB Mass Storage disk drive.
351 As its storage repository it can use a regular file or a block
352 device (in much the same way as the "loop" device driver),
353 specified as a module parameter or sysfs option.
355 config USB_CONFIGFS_F_LB_SS
356 bool "Loopback and sourcesink function (for testing)"
357 depends on USB_CONFIGFS
360 Loopback function loops back a configurable number of transfers.
361 Sourcesink function either sinks and sources bulk data.
362 It also implements control requests, for "chapter 9" conformance.
363 Make this be the first driver you try using on top of any new
364 USB peripheral controller driver. Then you can use host-side
365 test software, like the "usbtest" driver, to put your hardware
366 and its driver through a basic set of functional tests.
368 config USB_CONFIGFS_F_FS
369 bool "Function filesystem (FunctionFS)"
370 depends on USB_CONFIGFS
373 The Function Filesystem (FunctionFS) lets one create USB
374 composite functions in user space in the same way GadgetFS
375 lets one create USB gadgets in user space. This allows creation
376 of composite gadgets such that some of the functions are
377 implemented in kernel space (for instance Ethernet, serial or
378 mass storage) and other are implemented in user space.
380 config USB_CONFIGFS_F_MTP
382 depends on USB_CONFIGFS
385 USB gadget MTP support
387 config USB_CONFIGFS_F_PTP
389 depends on USB_CONFIGFS && USB_CONFIGFS_F_MTP
392 USB gadget PTP support
394 config USB_CONFIGFS_F_UAC1
395 bool "Audio Class 1.0"
396 depends on USB_CONFIGFS
398 select USB_LIBCOMPOSITE
402 This Audio function implements 1 AudioControl interface,
403 1 AudioStreaming Interface each for USB-OUT and USB-IN.
404 This driver requires a real Audio codec to be present
407 config USB_CONFIGFS_F_UAC2
408 bool "Audio Class 2.0"
409 depends on USB_CONFIGFS
411 select USB_LIBCOMPOSITE
415 This Audio function is compatible with USB Audio Class
416 specification 2.0. It implements 1 AudioControl interface,
417 1 AudioStreaming Interface each for USB-OUT and USB-IN.
418 This driver doesn't expect any real Audio codec to be present
419 on the device - the audio streams are simply sinked to and
420 sourced from a virtual ALSA sound card created. The user-space
421 application may choose to do whatever it wants with the data
422 received from the USB Host and choose to provide whatever it
423 wants as audio data to the USB Host.
425 config USB_CONFIGFS_F_MIDI
427 depends on USB_CONFIGFS
429 select USB_LIBCOMPOSITE
433 The MIDI Function acts as a USB Audio device, with one MIDI
434 input and one MIDI output. These MIDI jacks appear as
435 a sound "card" in the ALSA sound system. Other MIDI
436 connections can then be made on the gadget system, using
437 ALSA's aconnect utility etc.
439 config USB_CONFIGFS_F_HID
441 depends on USB_CONFIGFS
444 The HID function driver provides generic emulation of USB
445 Human Interface Devices (HID).
447 For more information, see Documentation/usb/gadget_hid.txt.
449 config USB_CONFIGFS_F_UVC
450 bool "USB Webcam function"
451 depends on USB_CONFIGFS
453 select VIDEOBUF2_VMALLOC
456 The Webcam function acts as a composite USB Audio and Video Class
457 device. It provides a userspace API to process UVC control requests
458 and stream video data to the host.
460 config USB_CONFIGFS_F_PRINTER
461 bool "Printer function"
463 depends on USB_CONFIGFS
465 The Printer function channels data between the USB host and a
466 userspace program driving the print engine. The user space
467 program reads and writes the device file /dev/g_printer<X> to
468 receive or send printer data. It can use ioctl calls to
469 the device file to get or set printer status.
471 For more information, see Documentation/usb/gadget_printer.txt
472 which includes sample code for accessing the device file.
474 source "drivers/usb/gadget/legacy/Kconfig"