3. USB Power Interface

The power interface is identified by bInterfaceClass = 0xff and bInterfaceSubclass = 0x50 ('P').

3.1. Control Requests

Control requests are vendor-specific interface-directed, i.e. with bmRequestType = 0x41 or 0xc1 and the lower half of wIndex containing bInterfaceNumber.

3.1.1. Set enable

bmRequestType

bRequest

wValue

wIndex

wLength

0x41

0x01

Enable

Channel << 8 | bInterfaceNumber

0

Channel

Description

0x00

VTREF

0x01

VTPWR

0xFF

All channels

3.1.2. Set voltage

bmRequestType

bRequest

wValue

wIndex

wLength

0x41

0x02

Voltage

Channel << 8 | bInterfaceNumber

0

Channel

Description

0x00

VTREF

0x01

VTPWR

Voltage is expressed in millivolts.

3.1.3. Get status

bmRequestType

bRequest

wValue

wIndex

wLength

0xc1

TBD

TBD

bInterfaceNumber

TBD