I’m trying to understand the system-level behavior of power transfer between two Android devices connected via USB-C.

From what I understand, USB-C with Power Delivery allows devices to act as either a power source or sink depending on negotiation. However, I’m unclear about how much control is available at different layers of the system.

Specifically:

- Can an Android application or system service control or override power direction (source vs sink) between two connected phones?

- Is it possible to programmatically limit or control the amount of current flowing between devices?

- Which aspects of this behavior are handled strictly at the hardware / firmware / OEM level, versus being accessible through Android APIs or system configuration?

I’m not trying to implement a specific solution yet — just trying to understand the architectural boundaries and limitations of power control between devices.

Any insights into how this works in practice would be very helpful.