Add USB Controller Auto-Detection and Configuration

[mihai-chiorean]

Description

Different boards use different USB controllers (dwc2, dwc3, tegra-xudc). The gadget should auto-detect and configure appropriately.

Current Problem

The current implementation assumes dwc2 controller and doesn't adapt to different hardware platforms.

Implementation

Detect USB controller type and configure:

• USB version (2.0 vs 3.0)
• Power settings (bus-powered vs self-powered)
• Device class and attributes

Detection Logic

# Check for dwc3 (USB 3.x)
if lsmod | grep -q "dwc3" || find /sys/class/udc -name "*dwc3*"; then
    USB_VERSION="0x0300"  # USB 3.0
    USB_CONTROLLER="dwc3"
# Check for dwc2 (USB 2.0)
elif lsmod | grep -q "dwc2" || find /sys/class/udc -name "*dwc2*"; then
    USB_VERSION="0x0200"  # USB 2.0
    USB_CONTROLLER="dwc2"
# Check for Tegra (Jetson)
elif lsmod | grep -q "tegra_xudc" || find /sys/class/udc -name "*tegra*"; then
    USB_VERSION="0x0300"  # USB 3.0
    USB_CONTROLLER="tegra-xudc"
fi

Power Configuration

if [ "$USB_CONTROLLER" = "dwc3" ]; then
    # Self-powered device
    echo 0xC0 > configs/c.1/bmAttributes
else
    # Bus-powered device
    echo 0x80 > configs/c.1/bmAttributes
    echo 250 > configs/c.1/MaxPower
fi

Acceptance Criteria

• Correctly identifies dwc2, dwc3, tegra-xudc controllers
• Sets USB version based on controller capabilities
• Configures power settings appropriately
• Works across RPi, Jetson, and generic ARM platforms
• Logs detected controller for debugging
• Handles unknown controllers gracefully