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 |