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"
21 USB is a master/slave protocol, organized with one master
22 host (such as a PC) controlling up to 127 peripheral devices.
23 The USB hardware is asymmetric, which makes it easier to set up:
24 you can't connect a "to-the-host" connector to a peripheral.
26 Linux can run in the host, or in the peripheral. In both cases
27 you need a low level bus controller driver, and some software
28 talking to it. Peripheral controllers are often discrete silicon,
29 or are integrated with the CPU in a microcontroller. The more
30 familiar host side controllers have names like "EHCI", "OHCI",
31 or "UHCI", and are usually integrated into southbridges on PC
34 Enable this configuration option if you want to run Linux inside
35 a USB peripheral device. Configure one hardware driver for your
36 peripheral/device side bus controller, and a "gadget driver" for
37 your peripheral protocol. (If you use modular gadget drivers,
38 you may configure more than one.)
40 If in doubt, say "N" and don't enable these drivers; most people
41 don't have this kind of hardware (except maybe inside Linux PDAs).
43 For more information, see <http://www.linux-usb.org/gadget> and
44 the kernel documentation for this API.
48 config USB_GADGET_DEBUG
49 bool "Debugging messages (DEVELOPMENT)"
50 depends on DEBUG_KERNEL
52 Many controller and gadget drivers will print some debugging
53 messages if you use this option to ask for those messages.
55 Avoid enabling these messages, even if you're actively
56 debugging such a driver. Many drivers will emit so many
57 messages that the driver timings are affected, which will
58 either create new failure modes or remove the one you're
59 trying to track down. Never enable these messages for a
62 config USB_GADGET_VERBOSE
63 bool "Verbose debugging Messages (DEVELOPMENT)"
64 depends on USB_GADGET_DEBUG
66 Many controller and gadget drivers will print verbose debugging
67 messages if you use this option to ask for those messages.
69 Avoid enabling these messages, even if you're actively
70 debugging such a driver. Many drivers will emit so many
71 messages that the driver timings are affected, which will
72 either create new failure modes or remove the one you're
73 trying to track down. Never enable these messages for a
76 config USB_GADGET_DEBUG_FILES
77 bool "Debugging information files (DEVELOPMENT)"
80 Some of the drivers in the "gadget" framework can expose
81 debugging information in files such as /proc/driver/udc
82 (for a peripheral controller). The information in these
83 files may help when you're troubleshooting or bringing up a
84 driver on a new board. Enable these files by choosing "Y"
85 here. If in doubt, or to conserve kernel memory, say "N".
87 config USB_GADGET_DEBUG_FS
88 bool "Debugging information files in debugfs (DEVELOPMENT)"
91 Some of the drivers in the "gadget" framework can expose
92 debugging information in files under /sys/kernel/debug/.
93 The information in these files may help when you're
94 troubleshooting or bringing up a driver on a new board.
95 Enable these files by choosing "Y" here. If in doubt, or
96 to conserve kernel memory, say "N".
98 config USB_GADGET_VBUS_DRAW
99 int "Maximum VBUS Power usage (2-500 mA)"
103 Some devices need to draw power from USB when they are
104 configured, perhaps to operate circuitry or to recharge
105 batteries. This is in addition to any local power supply,
106 such as an AC adapter or batteries.
108 Enter the maximum power your device draws through USB, in
109 milliAmperes. The permitted range of values is 2 - 500 mA;
110 0 mA would be legal, but can make some hosts misbehave.
112 This value will be used except for system-specific gadget
113 drivers that have more specific information.
115 config USB_GADGET_STORAGE_NUM_BUFFERS
116 int "Number of storage pipeline buffers"
120 Usually 2 buffers are enough to establish a good buffering
121 pipeline. The number may be increased in order to compensate
122 for a bursty VFS behaviour. For instance there may be CPU wake up
123 latencies that makes the VFS to appear bursty in a system with
124 an CPU on-demand governor. Especially if DMA is doing IO to
125 offload the CPU. In this case the CPU will go into power
126 save often and spin up occasionally to move data within VFS.
127 If selecting USB_GADGET_DEBUG_FILES this value may be set by
128 a module parameter as well.
131 config U_SERIAL_CONSOLE
132 bool "Serial gadget console support"
133 depends on USB_U_SERIAL
135 It supports the serial gadget can be used as a console.
137 source "drivers/usb/gadget/udc/Kconfig"
143 # composite based drivers
144 config USB_LIBCOMPOSITE
147 depends on USB_GADGET
188 config USB_F_MASS_STORAGE
197 config USB_F_UAC1_LEGACY
218 # this first set of drivers all depend on bulk-capable hardware.
221 tristate "USB Gadget 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
269 NCM is an advanced protocol for Ethernet encapsulation, allows
270 grouping of several ethernet frames into one USB transfer and
271 different alignment possibilities.
273 config USB_CONFIGFS_ECM
274 bool "Ethernet Control Model (CDC ECM)"
275 depends on USB_CONFIGFS
280 The "Communication Device Class" (CDC) Ethernet Control Model.
281 That protocol is often avoided with pure Ethernet adapters, in
282 favor of simpler vendor-specific hardware, but is widely
283 supported by firmware for smart network devices.
285 config USB_CONFIGFS_ECM_SUBSET
286 bool "Ethernet Control Model (CDC ECM) subset"
287 depends on USB_CONFIGFS
292 On hardware that can't implement the full protocol,
293 a simple CDC subset is used, placing fewer demands on USB.
295 config USB_CONFIGFS_RNDIS
297 depends on USB_CONFIGFS
302 Microsoft Windows XP bundles the "Remote NDIS" (RNDIS) protocol,
303 and Microsoft provides redistributable binary RNDIS drivers for
304 older versions of Windows.
306 To make MS-Windows work with this, use Documentation/usb/linux.inf
307 as the "driver info file". For versions of MS-Windows older than
308 XP, you'll need to download drivers from Microsoft's website; a URL
309 is given in comments found in that info file.
311 config USB_CONFIGFS_EEM
312 bool "Ethernet Emulation Model (EEM)"
313 depends on USB_CONFIGFS
319 CDC EEM is a newer USB standard that is somewhat simpler than CDC ECM
320 and therefore can be supported by more hardware. Technically ECM and
321 EEM are designed for different applications. The ECM model extends
322 the network interface to the target (e.g. a USB cable modem), and the
323 EEM model is for mobile devices to communicate with hosts using
324 ethernet over USB. For Linux gadgets, however, the interface with
325 the host is the same (a usbX device), so the differences are minimal.
327 config USB_CONFIGFS_PHONET
328 bool "Phonet protocol"
329 depends on USB_CONFIGFS
335 The Phonet protocol implementation for USB device.
337 config USB_CONFIGFS_MASS_STORAGE
339 depends on USB_CONFIGFS
341 select USB_F_MASS_STORAGE
343 The Mass Storage Gadget acts as a USB Mass Storage disk drive.
344 As its storage repository it can use a regular file or a block
345 device (in much the same way as the "loop" device driver),
346 specified as a module parameter or sysfs option.
348 config USB_CONFIGFS_F_LB_SS
349 bool "Loopback and sourcesink function (for testing)"
350 depends on USB_CONFIGFS
353 Loopback function loops back a configurable number of transfers.
354 Sourcesink function either sinks and sources bulk data.
355 It also implements control requests, for "chapter 9" conformance.
356 Make this be the first driver you try using on top of any new
357 USB peripheral controller driver. Then you can use host-side
358 test software, like the "usbtest" driver, to put your hardware
359 and its driver through a basic set of functional tests.
361 config USB_CONFIGFS_F_FS
362 bool "Function filesystem (FunctionFS)"
363 depends on USB_CONFIGFS
366 The Function Filesystem (FunctionFS) lets one create USB
367 composite functions in user space in the same way GadgetFS
368 lets one create USB gadgets in user space. This allows creation
369 of composite gadgets such that some of the functions are
370 implemented in kernel space (for instance Ethernet, serial or
371 mass storage) and other are implemented in user space.
373 config USB_CONFIGFS_F_UAC1
374 bool "Audio Class 1.0"
375 depends on USB_CONFIGFS
377 select USB_LIBCOMPOSITE
382 This Audio function implements 1 AudioControl interface,
383 1 AudioStreaming Interface each for USB-OUT and USB-IN.
384 This driver doesn't expect any real Audio codec to be present
385 on the device - the audio streams are simply sinked to and
386 sourced from a virtual ALSA sound card created. The user-space
387 application may choose to do whatever it wants with the data
388 received from the USB Host and choose to provide whatever it
389 wants as audio data to the USB Host.
391 config USB_CONFIGFS_F_UAC1_LEGACY
392 bool "Audio Class 1.0 (legacy implementation)"
393 depends on USB_CONFIGFS
395 select USB_LIBCOMPOSITE
397 select USB_F_UAC1_LEGACY
399 This Audio function implements 1 AudioControl interface,
400 1 AudioStreaming Interface each for USB-OUT and USB-IN.
401 This is a legacy driver and requires a real Audio codec
402 to be present on the device.
404 config USB_CONFIGFS_F_UAC2
405 bool "Audio Class 2.0"
406 depends on USB_CONFIGFS
408 select USB_LIBCOMPOSITE
413 This Audio function is compatible with USB Audio Class
414 specification 2.0. It implements 1 AudioControl interface,
415 1 AudioStreaming Interface each for USB-OUT and USB-IN.
416 This driver doesn't expect any real Audio codec to be present
417 on the device - the audio streams are simply sinked to and
418 sourced from a virtual ALSA sound card created. The user-space
419 application may choose to do whatever it wants with the data
420 received from the USB Host and choose to provide whatever it
421 wants as audio data to the USB Host.
423 config USB_CONFIGFS_F_MIDI
425 depends on USB_CONFIGFS
427 select USB_LIBCOMPOSITE
431 The MIDI Function acts as a USB Audio device, with one MIDI
432 input and one MIDI output. These MIDI jacks appear as
433 a sound "card" in the ALSA sound system. Other MIDI
434 connections can then be made on the gadget system, using
435 ALSA's aconnect utility etc.
437 config USB_CONFIGFS_F_HID
439 depends on USB_CONFIGFS
442 The HID function driver provides generic emulation of USB
443 Human Interface Devices (HID).
445 For more information, see Documentation/usb/gadget_hid.txt.
447 config USB_CONFIGFS_F_UVC
448 bool "USB Webcam function"
449 depends on USB_CONFIGFS
450 depends on VIDEO_V4L2
452 select VIDEOBUF2_VMALLOC
455 The Webcam function acts as a composite USB Audio and Video Class
456 device. It provides a userspace API to process UVC control requests
457 and stream video data to the host.
459 config USB_CONFIGFS_F_PRINTER
460 bool "Printer function"
462 depends on USB_CONFIGFS
464 The Printer function channels data between the USB host and a
465 userspace program driving the print engine. The user space
466 program reads and writes the device file /dev/g_printer<X> to
467 receive or send printer data. It can use ioctl calls to
468 the device file to get or set printer status.
470 For more information, see Documentation/usb/gadget_printer.txt
471 which includes sample code for accessing the device file.
473 config USB_CONFIGFS_F_TCM
474 bool "USB Gadget Target Fabric"
475 depends on TARGET_CORE
476 depends on USB_CONFIGFS
477 select USB_LIBCOMPOSITE
480 This fabric is a USB gadget component. Two USB protocols are
481 supported that is BBB or BOT (Bulk Only Transport) and UAS
482 (USB Attached SCSI). BOT is advertised on alternative
483 interface 0 (primary) and UAS is on alternative interface 1.
484 Both protocols can work on USB2.0 and USB3.0.
485 UAS utilizes the USB 3.0 feature called streams support.
488 tristate "USB Gadget precomposed configurations"
492 A Linux "Gadget Driver" talks to the USB Peripheral Controller
493 driver through the abstract "gadget" API. Some other operating
494 systems call these "client" drivers, of which "class drivers"
495 are a subset (implementing a USB device class specification).
496 A gadget driver implements one or more USB functions using
497 the peripheral hardware.
499 Gadget drivers are hardware-neutral, or "platform independent",
500 except that they sometimes must understand quirks or limitations
501 of the particular controllers they work with. For example, when
502 a controller doesn't support alternate configurations or provide
503 enough of the right types of endpoints, the gadget driver might
504 not be able work with that controller, or might need to implement
505 a less common variant of a device class protocol.
507 The available choices each represent a single precomposed USB
508 gadget configuration. In the device model, each option contains
509 both the device instantiation as a child for a USB gadget
510 controller, and the relevant drivers for each function declared
513 source "drivers/usb/gadget/legacy/Kconfig"