sunxi represents the family of ARM SoCs from Allwinner Technology. This project contains a full function(PULL-UP, PULL-DOWN) generic GPIO driver SunxiDriver for Allwinner SoCs and some special GPIO drivers like OrangePiZeroDriver, OrangePiLite2Driver.

dotnet/iot#1130

// For Orange Pi Zero
using GpioController gpio = new GpioController(PinNumberingScheme.Board, new OrangePiZeroDriver());

// Open the GPIO pin.
gpio.OpenPin(7);
// Set the pin mode.
gpio.SetPinMode(7, PinMode.InputPullUp);
// Read current value of the pin.
PinValue value = gpio.Read(7);

// Beacuse this is a generic driver, the pin scheme can only be Logical.
// The base addresses can be found in the corresponding SoC datasheet.
using GpioController gpio = new GpioController(PinNumberingScheme.Logical, new SunxiDriver(cpuxPortBaseAddress: 0x01C20800, cpusPortBaseAddress: 0x01F02C00));

// Convert pin number to logical scheme.
int pinNumber = SunxiDriver.MapPinNumber(portController: 'A', port: 10);
gpio.OpenPin(pinNumber);
gpio.SetPinMode(pinNumber, PinMode.Output);
// Write a value to the pin.
gpio.Write(pinNumber, PinValue.High);

Benchmarking with Orange Pi Zero. The operating system is Armbian buster, Linux kernel version is 5.10.16, and .NET version is 5.0.3. The test uses different GPIO drivers to quickly switch the state of GPIO 6 (Logical), and uses an oscilloscope to measure the average frequency of GPIO externally.

Drivers	Language	Library Version	Average Frequency
SunxiDriver	C#	-	185 KHz
SysFsDriver	C#	System.Device.Gpio 1.3.0	692 Hz
LibGpiodDriver	C#	System.Device.Gpio 1.3.0 libgpiod 1.2-3	81 KHz
wiringOP	C	35de015	1.10 MHz

1. Inheriting SunxiDriver Class.

   // For Allwinner H2+/H3
   public class Sun8iw7p1Driver : SunxiDriver { }

2. Overriding the GPIO base addresses.

   protected override int CpuxPortBaseAddress => 0x01C20800;
   protected override int CpusPortBaseAddress => 0x01F02C00;

1. Inherit the corresponding SoC class.

   public class OrangePiZeroDriver : Sun8iw7p1Driver { }

2. Overriding the mapping method for converting a board pin number to the driver's logical numbering scheme.

   // Mapping from board pins to logic pins.
   private static readonly int[] _pinNumberConverter = new int[27]
   {
       -1, -1, -1, MapPinNumber('A', 12), -1, MapPinNumber('A', 11), -1, MapPinNumber('A', 6), MapPinNumber('G', 6), -1,
       MapPinNumber('G', 7), MapPinNumber('A', 1), MapPinNumber('A', 7), MapPinNumber('A', 0), -1, MapPinNumber('A', 3),
       MapPinNumber('A', 19), -1, MapPinNumber('A', 18), MapPinNumber('A', 15), -1, MapPinNumber('A', 16), MapPinNumber('A', 2),
       MapPinNumber('A', 14), MapPinNumber('A', 13), -1, MapPinNumber('A', 10)
   };
   
   protected override int PinCount => 17;
   
   protected internal override int ConvertPinNumberToLogicalNumberingScheme(int pinNumber)
   {
       int num = _pinNumberConverter[pinNumber];
       return num != -1 ? num : 
           throw new ArgumentException($"Board (header) pin {pinNumber} is not a GPIO pin on the {GetType().Name} device.", nameof(pinNumber));
   }

The wiki of the linux-sunxi community: https://linux-sunxi.org/Main_Page

• Orange Pi Zero
• Switch
• Male/Female Jumper Wires

• Switch 1 - Board Pin7 (GPIO 6)
• Switch 2 - GND

cd SunxiGpioDriver.Samples
dotnet publish -c release -r linux-arm -o YOUR_FOLDER
sudo dotnet YOUR_FOLDER/SunxiGpioDriver.Samples.dll

docker build -t sunxi-sample -f Dockerfile .
docker run --rm -it --privileged=true --device=/dev/mem sunxi-sample