This is an open source clone of a Marvell MDIO USB adapter which can be used to interface MDIO of Ethernet switch chips and PHYs. Mainline Linux kernel is there is as interface hardware a Raspberry Pi Pico 1 is used.
- Generic interface to MDIO Ethernet switch chips and Ethernet PHYs
- Mainline Linux kernel support due mvusb driver
- Interfacing the Linux MDIO subsystem
- Usage of tools like
mdio-tools(https://github.com/wkz/mdio-tools) - Interfacing Linux DSA and switchdev
- Works out of the box on Ubuntu 24.04
- Implements a Marvell MDIO USB adapter clone
- A LED is indicating USB/MDIO traffic
- Raspberry Pi Pico 1 support (RP2040)
Wire up the MDC and MDIO pins to your chip. Please note that the RP2040 uses a 3.3 V voltage level.
| Pin | GPIO | Function |
|---|---|---|
| 18 | - | Ground |
| 19 | GP14 | MDC |
| 20 | GP15 | MDIO |
The UART ports (8N1, baud. 115200) are just for debugging. The RAW MDIO data is visible there.
The Raspberry Pi Pico has an built-in LED with the following function.
| State | Function |
|---|---|
| on | USB initialized |
| off | USB error or device not powered |
| blinking | USB/MDIO traffic |
You can get mdio-tools here https://github.com/wkz/mdio-tools
Get link status
$ mdio mvusb*
DEV PHY-ID LINK
0x00 0x001cc852 down
0x01 0x001cc852 down
0x02 0x001cc852 up
0x03 0x001cc852 down
0x04 0x001cc852 down
0x05 0x001cc852 down
Get PHY2 information
$ mdio mvusb* phy 2
BMCR(0x00): 0x3100
flags: -reset -loopback +aneg-enable -power-down -isolate -aneg-restart
-collision-test
speed: 100-full
BMSR(0x01): 0x786d
capabilities: -100-t4 +100-tx-f +100-tx-h +10-t-f +10-t-h -100-t2-f -100-t2-h
flags: -ext-status +aneg-complete -remote-fault +aneg-capable +link
-jabber +ext-register
ID(0x02/0x03): 0x001cc852
Download usb-mdio-adapter.uf2 from the latest release.
Push and hold the BOOTSEL button as you plug the debugger device into your computer to mount a volume called "RPI-RP2".
Copy the UF2 file usb-mdio-adapter.uf2 onto the volume. The volume will dismount automatically after the file finishes copying onto the device.
Your device will reboot and now runs the USB to MDIO adapter firmware.
Check your kernel log (e.g. dmesg) you should see
[ +3,286310] usb 1-2: new full-speed USB device number 49 using xhci_hcd
[ +0,152680] usb 1-2: New USB device found, idVendor=1286, idProduct=1fa4, bcdDevice= 0.00
[ +0,000017] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ +0,000007] usb 1-2: Product: Marvell USB MDIO Adapter Clone
[ +0,000006] usb 1-2: Manufacturer: Albrecht Lohofener
It is now ready.
Please follow the SDK installation instructions for the Raspberry Pi Pico. Checkout this repository open Visual Studio Code and compile it.
Just raise up an issue.