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 DocBook 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_G_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
185 config USB_F_MASS_STORAGE
212 # this first set of drivers all depend on bulk-capable hardware.
215 tristate "USB functions configurable through configfs"
216 select USB_LIBCOMPOSITE
218 A Linux USB "gadget" can be set up through configfs.
219 If this is the case, the USB functions (which from the host's
220 perspective are seen as interfaces) and configurations are
221 specified simply by creating appropriate directories in configfs.
222 Associating functions with configurations is done by creating
223 appropriate symbolic links.
224 For more information see Documentation/usb/gadget_configfs.txt.
226 config USB_CONFIGFS_SERIAL
227 bool "Generic serial bulk in/out"
228 depends on USB_CONFIGFS
233 The function talks to the Linux-USB generic serial driver.
235 config USB_CONFIGFS_ACM
236 bool "Abstract Control Model (CDC ACM)"
237 depends on USB_CONFIGFS
242 ACM serial link. This function can be used to interoperate with
243 MS-Windows hosts or with the Linux-USB "cdc-acm" driver.
245 config USB_CONFIGFS_OBEX
246 bool "Object Exchange Model (CDC OBEX)"
247 depends on USB_CONFIGFS
252 You will need a user space OBEX server talking to /dev/ttyGS*,
253 since the kernel itself doesn't implement the OBEX protocol.
255 config USB_CONFIGFS_NCM
256 bool "Network Control Model (CDC NCM)"
257 depends on USB_CONFIGFS
263 NCM is an advanced protocol for Ethernet encapsulation, allows
264 grouping of several ethernet frames into one USB transfer and
265 different alignment possibilities.
267 config USB_CONFIGFS_ECM
268 bool "Ethernet Control Model (CDC ECM)"
269 depends on USB_CONFIGFS
274 The "Communication Device Class" (CDC) Ethernet Control Model.
275 That protocol is often avoided with pure Ethernet adapters, in
276 favor of simpler vendor-specific hardware, but is widely
277 supported by firmware for smart network devices.
279 config USB_CONFIGFS_ECM_SUBSET
280 bool "Ethernet Control Model (CDC ECM) subset"
281 depends on USB_CONFIGFS
286 On hardware that can't implement the full protocol,
287 a simple CDC subset is used, placing fewer demands on USB.
289 config USB_CONFIGFS_RNDIS
291 depends on USB_CONFIGFS
296 Microsoft Windows XP bundles the "Remote NDIS" (RNDIS) protocol,
297 and Microsoft provides redistributable binary RNDIS drivers for
298 older versions of Windows.
300 To make MS-Windows work with this, use Documentation/usb/linux.inf
301 as the "driver info file". For versions of MS-Windows older than
302 XP, you'll need to download drivers from Microsoft's website; a URL
303 is given in comments found in that info file.
305 config USB_CONFIGFS_EEM
306 bool "Ethernet Emulation Model (EEM)"
307 depends on USB_CONFIGFS
313 CDC EEM is a newer USB standard that is somewhat simpler than CDC ECM
314 and therefore can be supported by more hardware. Technically ECM and
315 EEM are designed for different applications. The ECM model extends
316 the network interface to the target (e.g. a USB cable modem), and the
317 EEM model is for mobile devices to communicate with hosts using
318 ethernet over USB. For Linux gadgets, however, the interface with
319 the host is the same (a usbX device), so the differences are minimal.
321 config USB_CONFIGFS_PHONET
322 bool "Phonet protocol"
323 depends on USB_CONFIGFS
329 The Phonet protocol implementation for USB device.
331 config USB_CONFIGFS_MASS_STORAGE
333 depends on USB_CONFIGFS
335 select USB_F_MASS_STORAGE
337 The Mass Storage Gadget acts as a USB Mass Storage disk drive.
338 As its storage repository it can use a regular file or a block
339 device (in much the same way as the "loop" device driver),
340 specified as a module parameter or sysfs option.
342 config USB_CONFIGFS_F_LB_SS
343 bool "Loopback and sourcesink function (for testing)"
344 depends on USB_CONFIGFS
347 Loopback function loops back a configurable number of transfers.
348 Sourcesink function either sinks and sources bulk data.
349 It also implements control requests, for "chapter 9" conformance.
350 Make this be the first driver you try using on top of any new
351 USB peripheral controller driver. Then you can use host-side
352 test software, like the "usbtest" driver, to put your hardware
353 and its driver through a basic set of functional tests.
355 config USB_CONFIGFS_F_FS
356 bool "Function filesystem (FunctionFS)"
357 depends on USB_CONFIGFS
360 The Function Filesystem (FunctionFS) lets one create USB
361 composite functions in user space in the same way GadgetFS
362 lets one create USB gadgets in user space. This allows creation
363 of composite gadgets such that some of the functions are
364 implemented in kernel space (for instance Ethernet, serial or
365 mass storage) and other are implemented in user space.
367 config USB_CONFIGFS_F_UAC1
368 bool "Audio Class 1.0"
369 depends on USB_CONFIGFS
371 select USB_LIBCOMPOSITE
375 This Audio function implements 1 AudioControl interface,
376 1 AudioStreaming Interface each for USB-OUT and USB-IN.
377 This driver requires a real Audio codec to be present
380 config USB_CONFIGFS_F_UAC2
381 bool "Audio Class 2.0"
382 depends on USB_CONFIGFS
384 select USB_LIBCOMPOSITE
388 This Audio function is compatible with USB Audio Class
389 specification 2.0. It implements 1 AudioControl interface,
390 1 AudioStreaming Interface each for USB-OUT and USB-IN.
391 This driver doesn't expect any real Audio codec to be present
392 on the device - the audio streams are simply sinked to and
393 sourced from a virtual ALSA sound card created. The user-space
394 application may choose to do whatever it wants with the data
395 received from the USB Host and choose to provide whatever it
396 wants as audio data to the USB Host.
398 config USB_CONFIGFS_F_MIDI
400 depends on USB_CONFIGFS
402 select USB_LIBCOMPOSITE
406 The MIDI Function acts as a USB Audio device, with one MIDI
407 input and one MIDI output. These MIDI jacks appear as
408 a sound "card" in the ALSA sound system. Other MIDI
409 connections can then be made on the gadget system, using
410 ALSA's aconnect utility etc.
412 config USB_CONFIGFS_F_HID
414 depends on USB_CONFIGFS
417 The HID function driver provides generic emulation of USB
418 Human Interface Devices (HID).
420 For more information, see Documentation/usb/gadget_hid.txt.
422 config USB_CONFIGFS_F_UVC
423 bool "USB Webcam function"
424 depends on USB_CONFIGFS
425 depends on VIDEO_V4L2
427 select VIDEOBUF2_VMALLOC
430 The Webcam function acts as a composite USB Audio and Video Class
431 device. It provides a userspace API to process UVC control requests
432 and stream video data to the host.
434 config USB_CONFIGFS_F_PRINTER
435 bool "Printer function"
437 depends on USB_CONFIGFS
439 The Printer function channels data between the USB host and a
440 userspace program driving the print engine. The user space
441 program reads and writes the device file /dev/g_printer<X> to
442 receive or send printer data. It can use ioctl calls to
443 the device file to get or set printer status.
445 For more information, see Documentation/usb/gadget_printer.txt
446 which includes sample code for accessing the device file.
448 config USB_CONFIGFS_F_TCM
449 bool "USB Gadget Target Fabric"
450 depends on TARGET_CORE
451 depends on USB_CONFIGFS
452 select USB_LIBCOMPOSITE
455 This fabric is a USB gadget component. Two USB protocols are
456 supported that is BBB or BOT (Bulk Only Transport) and UAS
457 (USB Attached SCSI). BOT is advertised on alternative
458 interface 0 (primary) and UAS is on alternative interface 1.
459 Both protocols can work on USB2.0 and USB3.0.
460 UAS utilizes the USB 3.0 feature called streams support.
463 tristate "USB Gadget Drivers"
467 A Linux "Gadget Driver" talks to the USB Peripheral Controller
468 driver through the abstract "gadget" API. Some other operating
469 systems call these "client" drivers, of which "class drivers"
470 are a subset (implementing a USB device class specification).
471 A gadget driver implements one or more USB functions using
472 the peripheral hardware.
474 Gadget drivers are hardware-neutral, or "platform independent",
475 except that they sometimes must understand quirks or limitations
476 of the particular controllers they work with. For example, when
477 a controller doesn't support alternate configurations or provide
478 enough of the right types of endpoints, the gadget driver might
479 not be able work with that controller, or might need to implement
480 a less common variant of a device class protocol.
482 source "drivers/usb/gadget/legacy/Kconfig"