1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
|
#
# USB Gadget support on a system involves
# (a) a peripheral controller, and
# (b) the gadget driver using it.
#
# NOTE: Gadget support ** DOES NOT ** depend on host-side CONFIG_USB !!
#
# - Host systems (like PCs) need CONFIG_USB (with "A" jacks).
# - Peripherals (like PDAs) need CONFIG_USB_GADGET (with "B" jacks).
# - Some systems have both kinds of controllers.
#
# With help from a special transceiver and a "Mini-AB" jack, systems with
# both kinds of controller can also support "USB On-the-Go" (CONFIG_USB_OTG).
#
menuconfig USB_GADGET
bool "USB Gadget Support"
help
USB is a master/slave protocol, organized with one master
host (such as a PC) controlling up to 127 peripheral devices.
The USB hardware is asymmetric, which makes it easier to set up:
you can't connect a "to-the-host" connector to a peripheral.
U-Boot can run in the host, or in the peripheral. In both cases
you need a low level bus controller driver, and some software
talking to it. Peripheral controllers are often discrete silicon,
or are integrated with the CPU in a microcontroller. The more
familiar host side controllers have names like "EHCI", "OHCI",
or "UHCI", and are usually integrated into southbridges on PC
motherboards.
Enable this configuration option if you want to run U-Boot inside
a USB peripheral device. Configure one hardware driver for your
peripheral/device side bus controller, and a "gadget driver" for
your peripheral protocol.
if USB_GADGET
config USB_GADGET_VBUS_DRAW
int "Maximum VBUS Power usage (2-500 mA)"
range 2 500
default 2
help
Some devices need to draw power from USB when they are
configured, perhaps to operate circuitry or to recharge
batteries. This is in addition to any local power supply,
such as an AC adapter or batteries.
Enter the maximum power your device draws through USB, in
milliAmperes. The permitted range of values is 2 - 500 mA;
0 mA would be legal, but can make some hosts misbehave.
This value will be used except for system-specific gadget
drivers that have more specific information.
endif # USB_GADGET
|
