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