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 boolean "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 boolean "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 boolean "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
185 tristate "USB Gadget Drivers"
188 A Linux "Gadget Driver" talks to the USB Peripheral Controller
189 driver through the abstract "gadget" API. Some other operating
190 systems call these "client" drivers, of which "class drivers"
191 are a subset (implementing a USB device class specification).
192 A gadget driver implements one or more USB functions using
193 the peripheral hardware.
195 Gadget drivers are hardware-neutral, or "platform independent",
196 except that they sometimes must understand quirks or limitations
197 of the particular controllers they work with. For example, when
198 a controller doesn't support alternate configurations or provide
199 enough of the right types of endpoints, the gadget driver might
200 not be able work with that controller, or might need to implement
201 a less common variant of a device class protocol.
203 # this first set of drivers all depend on bulk-capable hardware.
206 tristate "USB functions configurable through configfs"
207 select USB_LIBCOMPOSITE
209 A Linux USB "gadget" can be set up through configfs.
210 If this is the case, the USB functions (which from the host's
211 perspective are seen as interfaces) and configurations are
212 specified simply by creating appropriate directories in configfs.
213 Associating functions with configurations is done by creating
214 appropriate symbolic links.
215 For more information see Documentation/usb/gadget_configfs.txt.
217 config USB_CONFIGFS_SERIAL
218 boolean "Generic serial bulk in/out"
219 depends on USB_CONFIGFS
224 The function talks to the Linux-USB generic serial driver.
226 config USB_CONFIGFS_ACM
227 boolean "Abstract Control Model (CDC ACM)"
228 depends on USB_CONFIGFS
233 ACM serial link. This function can be used to interoperate with
234 MS-Windows hosts or with the Linux-USB "cdc-acm" driver.
236 config USB_CONFIGFS_OBEX
237 boolean "Object Exchange Model (CDC OBEX)"
238 depends on USB_CONFIGFS
243 You will need a user space OBEX server talking to /dev/ttyGS*,
244 since the kernel itself doesn't implement the OBEX protocol.
246 config USB_CONFIGFS_NCM
247 boolean "Network Control Model (CDC NCM)"
248 depends on USB_CONFIGFS
253 NCM is an advanced protocol for Ethernet encapsulation, allows
254 grouping of several ethernet frames into one USB transfer and
255 different alignment possibilities.
257 config USB_CONFIGFS_ECM
258 boolean "Ethernet Control Model (CDC ECM)"
259 depends on USB_CONFIGFS
264 The "Communication Device Class" (CDC) Ethernet Control Model.
265 That protocol is often avoided with pure Ethernet adapters, in
266 favor of simpler vendor-specific hardware, but is widely
267 supported by firmware for smart network devices.
269 config USB_CONFIGFS_ECM_SUBSET
270 boolean "Ethernet Control Model (CDC ECM) subset"
271 depends on USB_CONFIGFS
276 On hardware that can't implement the full protocol,
277 a simple CDC subset is used, placing fewer demands on USB.
279 config USB_CONFIGFS_RNDIS
281 depends on USB_CONFIGFS
286 Microsoft Windows XP bundles the "Remote NDIS" (RNDIS) protocol,
287 and Microsoft provides redistributable binary RNDIS drivers for
288 older versions of Windows.
290 To make MS-Windows work with this, use Documentation/usb/linux.inf
291 as the "driver info file". For versions of MS-Windows older than
292 XP, you'll need to download drivers from Microsoft's website; a URL
293 is given in comments found in that info file.
295 config USB_CONFIGFS_EEM
296 bool "Ethernet Emulation Model (EEM)"
297 depends on USB_CONFIGFS
302 CDC EEM is a newer USB standard that is somewhat simpler than CDC ECM
303 and therefore can be supported by more hardware. Technically ECM and
304 EEM are designed for different applications. The ECM model extends
305 the network interface to the target (e.g. a USB cable modem), and the
306 EEM model is for mobile devices to communicate with hosts using
307 ethernet over USB. For Linux gadgets, however, the interface with
308 the host is the same (a usbX device), so the differences are minimal.
310 config USB_CONFIGFS_PHONET
311 boolean "Phonet protocol"
312 depends on USB_CONFIGFS
318 The Phonet protocol implementation for USB device.
320 config USB_CONFIGFS_MASS_STORAGE
321 boolean "Mass storage"
322 depends on USB_CONFIGFS
324 select USB_F_MASS_STORAGE
326 The Mass Storage Gadget acts as a USB Mass Storage disk drive.
327 As its storage repository it can use a regular file or a block
328 device (in much the same way as the "loop" device driver),
329 specified as a module parameter or sysfs option.
331 config USB_CONFIGFS_F_LB_SS
332 boolean "Loopback and sourcesink function (for testing)"
333 depends on USB_CONFIGFS
336 Loopback function loops back a configurable number of transfers.
337 Sourcesink function either sinks and sources bulk data.
338 It also implements control requests, for "chapter 9" conformance.
339 Make this be the first driver you try using on top of any new
340 USB peripheral controller driver. Then you can use host-side
341 test software, like the "usbtest" driver, to put your hardware
342 and its driver through a basic set of functional tests.
344 config USB_CONFIGFS_F_FS
345 boolean "Function filesystem (FunctionFS)"
346 depends on USB_CONFIGFS
349 The Function Filesystem (FunctionFS) lets one create USB
350 composite functions in user space in the same way GadgetFS
351 lets one create USB gadgets in user space. This allows creation
352 of composite gadgets such that some of the functions are
353 implemented in kernel space (for instance Ethernet, serial or
354 mass storage) and other are implemented in user space.
356 source "drivers/usb/gadget/legacy/Kconfig"