% ioreg -p IOUSB > /tmp/a
# only a solid red light (pins GRND and BOOT0 jumpered)

% ioreg -p IOUSB > /tmp/b
# solid red light and solid green light

% ioreg -p IOUSB > /tmp/c
# nothing plugged in



% diff /tmp/a /tmp/c
13c13
<   +-o AppleUSBXHCI Root Hub Simulation@14000000  <class AppleUSBRootHubDevice, id 0x100000589, registered, matched, active, busy 0 (15 ms), retain 11>
---
>   +-o AppleUSBXHCI Root Hub Simulation@14000000  <class AppleUSBRootHubDevice, id 0x100000589, registered, matched, active, busy 0 (15 ms), retain 10>
18d17
<     +-o USB Serial@14300000  <class AppleUSBDevice, id 0x100004ca4, registered, matched, active, busy 0 (10 ms), retain 12>


% diff /tmp/b /tmp/c
13c13
<   +-o AppleUSBXHCI Root Hub Simulation@14000000  <class AppleUSBRootHubDevice, id 0x100000589, registered, matched, active, busy 0 (15 ms), retain 11>
---
>   +-o AppleUSBXHCI Root Hub Simulation@14000000  <class AppleUSBRootHubDevice, id 0x100000589, registered, matched, active, busy 0 (15 ms), retain 10>
18d17
<     +-o USB Serial@14300000  <class AppleUSBDevice, id 0x100004ce5, registered, matched, active, busy 0 (11 ms), retain 12>



system_profiler SPUSBDataType > /tmp/d
# red solid


system_profiler SPUSBDataType > /tmp/e
# nothing


% diff /tmp/d /tmp/e
38,48d37
<         USB Serial:
<
<           Product ID: 0x7523
<           Vendor ID: 0x1a86
<           Version: 2.64
<           Speed: Up to 12 Mb/s
<           Location ID: 0x14300000 / 33
<           Current Available (mA): 500
<           Current Required (mA): 98
<           Extra Operating Current (mA): 0