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