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
203 tristate "USB Gadget Drivers"
206 A Linux "Gadget Driver" talks to the USB Peripheral Controller
207 driver through the abstract "gadget" API. Some other operating
208 systems call these "client" drivers, of which "class drivers"
209 are a subset (implementing a USB device class specification).
210 A gadget driver implements one or more USB functions using
211 the peripheral hardware.
213 Gadget drivers are hardware-neutral, or "platform independent",
214 except that they sometimes must understand quirks or limitations
215 of the particular controllers they work with. For example, when
216 a controller doesn't support alternate configurations or provide
217 enough of the right types of endpoints, the gadget driver might
218 not be able work with that controller, or might need to implement
219 a less common variant of a device class protocol.
221 # this first set of drivers all depend on bulk-capable hardware.
224 tristate "USB functions configurable through configfs"
225 select USB_LIBCOMPOSITE
227 A Linux USB "gadget" can be set up through configfs.
228 If this is the case, the USB functions (which from the host's
229 perspective are seen as interfaces) and configurations are
230 specified simply by creating appropriate directories in configfs.
231 Associating functions with configurations is done by creating
232 appropriate symbolic links.
233 For more information see Documentation/usb/gadget_configfs.txt.
235 config USB_CONFIGFS_SERIAL
236 bool "Generic serial bulk in/out"
237 depends on USB_CONFIGFS
242 The function talks to the Linux-USB generic serial driver.
244 config USB_CONFIGFS_ACM
245 bool "Abstract Control Model (CDC ACM)"
246 depends on USB_CONFIGFS
251 ACM serial link. This function can be used to interoperate with
252 MS-Windows hosts or with the Linux-USB "cdc-acm" driver.
254 config USB_CONFIGFS_OBEX
255 bool "Object Exchange Model (CDC OBEX)"
256 depends on USB_CONFIGFS
261 You will need a user space OBEX server talking to /dev/ttyGS*,
262 since the kernel itself doesn't implement the OBEX protocol.
264 config USB_CONFIGFS_NCM
265 bool "Network Control Model (CDC NCM)"
266 depends on USB_CONFIGFS
272 NCM is an advanced protocol for Ethernet encapsulation, allows
273 grouping of several ethernet frames into one USB transfer and
274 different alignment possibilities.
276 config USB_CONFIGFS_ECM
277 bool "Ethernet Control Model (CDC ECM)"
278 depends on USB_CONFIGFS
283 The "Communication Device Class" (CDC) Ethernet Control Model.
284 That protocol is often avoided with pure Ethernet adapters, in
285 favor of simpler vendor-specific hardware, but is widely
286 supported by firmware for smart network devices.
288 config USB_CONFIGFS_ECM_SUBSET
289 bool "Ethernet Control Model (CDC ECM) subset"
290 depends on USB_CONFIGFS
295 On hardware that can't implement the full protocol,
296 a simple CDC subset is used, placing fewer demands on USB.
298 config USB_CONFIGFS_RNDIS
300 depends on USB_CONFIGFS
305 Microsoft Windows XP bundles the "Remote NDIS" (RNDIS) protocol,
306 and Microsoft provides redistributable binary RNDIS drivers for
307 older versions of Windows.
309 To make MS-Windows work with this, use Documentation/usb/linux.inf
310 as the "driver info file". For versions of MS-Windows older than
311 XP, you'll need to download drivers from Microsoft's website; a URL
312 is given in comments found in that info file.
314 config USB_CONFIGFS_EEM
315 bool "Ethernet Emulation Model (EEM)"
316 depends on USB_CONFIGFS
322 CDC EEM is a newer USB standard that is somewhat simpler than CDC ECM
323 and therefore can be supported by more hardware. Technically ECM and
324 EEM are designed for different applications. The ECM model extends
325 the network interface to the target (e.g. a USB cable modem), and the
326 EEM model is for mobile devices to communicate with hosts using
327 ethernet over USB. For Linux gadgets, however, the interface with
328 the host is the same (a usbX device), so the differences are minimal.
330 config USB_CONFIGFS_PHONET
331 bool "Phonet protocol"
332 depends on USB_CONFIGFS
338 The Phonet protocol implementation for USB device.
340 config USB_CONFIGFS_MASS_STORAGE
342 depends on USB_CONFIGFS
344 select USB_F_MASS_STORAGE
346 The Mass Storage Gadget acts as a USB Mass Storage disk drive.
347 As its storage repository it can use a regular file or a block
348 device (in much the same way as the "loop" device driver),
349 specified as a module parameter or sysfs option.
351 config USB_CONFIGFS_F_LB_SS
352 bool "Loopback and sourcesink function (for testing)"
353 depends on USB_CONFIGFS
356 Loopback function loops back a configurable number of transfers.
357 Sourcesink function either sinks and sources bulk data.
358 It also implements control requests, for "chapter 9" conformance.
359 Make this be the first driver you try using on top of any new
360 USB peripheral controller driver. Then you can use host-side
361 test software, like the "usbtest" driver, to put your hardware
362 and its driver through a basic set of functional tests.
364 config USB_CONFIGFS_F_FS
365 bool "Function filesystem (FunctionFS)"
366 depends on USB_CONFIGFS
369 The Function Filesystem (FunctionFS) lets one create USB
370 composite functions in user space in the same way GadgetFS
371 lets one create USB gadgets in user space. This allows creation
372 of composite gadgets such that some of the functions are
373 implemented in kernel space (for instance Ethernet, serial or
374 mass storage) and other are implemented in user space.
376 config USB_CONFIGFS_F_UAC1
377 bool "Audio Class 1.0"
378 depends on USB_CONFIGFS
380 select USB_LIBCOMPOSITE
384 This Audio function implements 1 AudioControl interface,
385 1 AudioStreaming Interface each for USB-OUT and USB-IN.
386 This driver requires a real Audio codec to be present
389 config USB_CONFIGFS_F_UAC2
390 bool "Audio Class 2.0"
391 depends on USB_CONFIGFS
393 select USB_LIBCOMPOSITE
397 This Audio function is compatible with USB Audio Class
398 specification 2.0. It implements 1 AudioControl interface,
399 1 AudioStreaming Interface each for USB-OUT and USB-IN.
400 This driver doesn't expect any real Audio codec to be present
401 on the device - the audio streams are simply sinked to and
402 sourced from a virtual ALSA sound card created. The user-space
403 application may choose to do whatever it wants with the data
404 received from the USB Host and choose to provide whatever it
405 wants as audio data to the USB Host.
407 config USB_CONFIGFS_F_MIDI
409 depends on USB_CONFIGFS
411 select USB_LIBCOMPOSITE
415 The MIDI Function acts as a USB Audio device, with one MIDI
416 input and one MIDI output. These MIDI jacks appear as
417 a sound "card" in the ALSA sound system. Other MIDI
418 connections can then be made on the gadget system, using
419 ALSA's aconnect utility etc.
421 config USB_CONFIGFS_F_HID
423 depends on USB_CONFIGFS
426 The HID function driver provides generic emulation of USB
427 Human Interface Devices (HID).
429 For more information, see Documentation/usb/gadget_hid.txt.
431 config USB_CONFIGFS_F_UVC
432 bool "USB Webcam function"
433 depends on USB_CONFIGFS
435 select VIDEOBUF2_VMALLOC
438 The Webcam function acts as a composite USB Audio and Video Class
439 device. It provides a userspace API to process UVC control requests
440 and stream video data to the host.
442 config USB_CONFIGFS_F_PRINTER
443 bool "Printer function"
445 depends on USB_CONFIGFS
447 The Printer function channels data between the USB host and a
448 userspace program driving the print engine. The user space
449 program reads and writes the device file /dev/g_printer<X> to
450 receive or send printer data. It can use ioctl calls to
451 the device file to get or set printer status.
453 For more information, see Documentation/usb/gadget_printer.txt
454 which includes sample code for accessing the device file.
456 source "drivers/usb/gadget/legacy/Kconfig"