Software

The mainline linux kernel (4.21) has support for:

• basic SOC features
• Ethernet
• USB
• parallel CSI
• RGB and TCON
• UART
• I²C
• SPI
• SDIO
• Audio
• LRADC0
• RTC
• Watchdog

Whats not implemented:

• CPU frequency scaling
• MIPI CSI
• Video Engine (encoding / decoding video)

Have a look at the documentation to find out how to build your own mainline kernel and rootfs.