Add Tca955x device family

src/devices/Tca955x/README.md

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+# Tca955x - I/O Expander device family
+
+## Summary
+
+The TCA955X device family provides 8/16-bit, general purpose I/O expansion for I2C. The devices can be configured with polariy invertion and interrupts.
+
+## Device Family
+
+The family contains the TCA9554 (8-bit) and the TCA9555 (16-bit) device. Both devices are compatible with 400kHz Bus speed.
+
+- **TCA9554**: [datasheet](https://www.ti.com/lit/ds/symlink/tca9554.pdf)
+- **TCA9555**: [datasheet](https://www.ti.com/lit/ds/symlink/tca9555.pdf)
+
+## Interrupt support
+
+The `Tca955x` has one interrupt pin. The corresponding pins need to be connected to a master GPIO controller for this feature to work. You can use a GPIO controller around the MCP device to handle everything for you:
+```csharp
+// Gpio controller from parent device (eg. Raspberry Pi)
+_gpioController = new GpioController();
+_i2c = I2cDevice.Create(new I2cConnectionSettings(1, 0x20));
+// The "Interrupt" line of the TCA9554 is connected to GPIO input 11 of the Raspi
+_device = new Tca9554(_i2c, 11, _gpioController, false);
+GpioController theDeviceController = new GpioController(_device);
+theDeviceController.OpenPin(1, PinMode.Input);
+theDeviceController.RegisterCallbackForPinValueChangedEvent(1, PinEventTypes.Rising, Callback);
+```
+
+## Binding Notes
+
+The bindings includes an `Tca955x` abstract class and derived for 8-bit `Tca9554` and 16-bit `Tca9555`.

src/devices/Tca955x/Register.cs

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+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Iot.Device.Tca955x
+{
+    /// <summary>
+    /// Register for the base class and the 8-Bit device
+    /// </summary>
+    public enum Register
+    {
+        /// <summary>
+        /// Register Adress for the Inputs P0 - P7
+        /// Only Read Allowed on this Register
+        /// </summary>
+        InputPort = 0x00,
+
+        /// <summary>
+        /// Register Adress for the Outputs P0 - P7
+        /// </summary>
+        OutputPort = 0x01,
+
+        /// <summary>
+        /// Register Adress for the Polarity Inversion P0 - P7
+        /// </summary>
+        PolarityInversionPort = 0x02,
+
+        /// <summary>
+        /// Register Adress for the Configuration P0 - P7
+        /// </summary>
+        ConfigurationPort = 0x03,
+    }
+}

src/devices/Tca955x/Tca9554.cs

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+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Device.Gpio;
+using System.Device.I2c;
+
+namespace Iot.Device.Tca955x
+{
+    /// <summary>
+    /// Class for the Tca9554 8-Bit I/O Exander
+    /// </summary>
+    public class Tca9554 : Tca955x
+    {
+        /// <summary>
+        /// Constructor for the Tca9554 I2C I/O Expander.
+        /// </summary>
+        /// <param name="device">The I2C device used for communication</param>
+        /// <param name="interrupt">The input pin number that is connected to the interrupt.</param>
+        /// <param name="gpioController">The controller for the reset and interrupt pins. If not specified, the default controller will be used.</param>
+        /// <param name="shouldDispose">True to dispose the Gpio Controller.</param>
+        public Tca9554(I2cDevice device, int interrupt = -1, GpioController? gpioController = null, bool shouldDispose = true)
+            : base(device, interrupt, gpioController, shouldDispose)
+        {
+        }
+
+        /// <inheritdoc/>
+        protected override int PinCount => 8;
+
+        /// <inheritdoc/>
+        protected override byte GetByteRegister(int pinNumber, ushort value)
+        {
+            return (byte)(value & 0xFF);
+        }
+
+        /// <inheritdoc/>
+        protected override int GetBitNumber(int pinNumber)
+        {
+            return pinNumber;
+        }
+
+        /// <inheritdoc/>
+        protected override byte GetRegisterIndex(int pinNumber, Register registerType)
+        {
+            // No conversion for 8-Bit devices
+            return (byte)registerType;
+        }
+
+        /// <summary>
+        /// Write a byte to the given Register.
+        /// </summary>
+        /// <param name="register">The given Register.</param>
+        /// <param name="value">The value to write.</param>
+        public void WriteByte(Register register, byte value) => InternalWriteByte((byte)register, value);
+
+        /// <summary>
+        /// Read a byte from the given Register.
+        /// </summary>
+        /// <param name="register">The given Register.</param>
+        /// <returns>The readed byte from the Register.</returns>
+        public byte ReadByte(Register register) => InternalReadByte((byte)register);
+    }
+}

src/devices/Tca955x/Tca9555.cs

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+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Device.Gpio;
+using System.Device.I2c;
+
+namespace Iot.Device.Tca955x
+{
+    /// <summary>
+    /// Class for the Tca9555 16-Bit I/O Exander
+    /// </summary>
+    public class Tca9555 : Tca955x
+    {
+        /// <summary>
+        /// Constructor for the Tca9555 I2C I/O Expander.
+        /// </summary>
+        /// <param name="device">The I2C Device the device is connected to. Expect an I2C Adress between 0x20 and 0x27</param>
+        /// <param name="interrupt">The input pin number that is connected to the interrupt.</param>
+        /// <param name="gpioController">The controller for the reset and interrupt pins. If not specified, the default controller will be used.</param>
+        /// <param name="shouldDispose">True to dispose the Gpio Controller.</param>
+        public Tca9555(I2cDevice device, int interrupt = -1, GpioController? gpioController = null, bool shouldDispose = true)
+            : base(device, interrupt, gpioController, shouldDispose)
+        {
+        }
+
+        /// <inheritdoc/>
+        protected override int PinCount => 16;
+
+        /// <inheritdoc/>
+        protected override byte GetByteRegister(int pinNumber, ushort value)
+        {
+            if (pinNumber >= 0 &&
+                pinNumber <= 7)
+            {
+                return (byte)(value & 0xFF);
+            }
+            else if (pinNumber >= 8 &&
+                     pinNumber <= 15)
+            {
+                return (byte)((value >> 8) & 0xFF);
+            }
+
+            return 0;
+        }
+
+        /// <inheritdoc/>
+        protected override int GetBitNumber(int pinNumber)
+        {
+            if (pinNumber >= 0 &&
+                pinNumber <= 7)
+            {
+                return pinNumber;
+            }
+            else if (pinNumber >= 8 &&
+                     pinNumber <= 15)
+            {
+                return pinNumber - 8;
+            }
+
+            return 0;
+        }
+
+        /// <inheritdoc/>
+        protected override byte GetRegisterIndex(int pinNumber, Register registerType)
+        {
+            byte register = (byte)registerType;
+            register += (byte)registerType;
+
+            if (pinNumber >= 0 &&
+                pinNumber <= 7)
+            {
+                return register;
+            }
+            else if (pinNumber >= 8 &&
+                     pinNumber <= 15)
+            {
+                return ++register;
+            }
+
+            throw new ArgumentOutOfRangeException(nameof(pinNumber));
+        }
+
+        /// <summary>
+        /// Write a byte to the given Register.
+        /// </summary>
+        /// <param name="register">The given Register.</param>
+        /// <param name="value">The value to write.</param>
+        public void WriteByte(Tca9555Register register, byte value) => InternalWriteByte((byte)register, value);
+
+        /// <summary>
+        /// Read a byte from the given Register.
+        /// </summary>
+        /// <param name="register">The given Register.</param>
+        /// <returns>The readed byte from the Register.</returns>
+        public byte ReadByte(Tca9555Register register) => InternalReadByte((byte)register);
+    }
+}

src/devices/Tca955x/Tca9555Register.cs

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+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Iot.Device.Tca955x
+{
+    /// <summary>
+    /// Register for the 16 Bit Device
+    /// </summary>
+    public enum Tca9555Register
+    {
+        /// <summary>
+        /// Register Adress for the Inputs P00 - P07
+        /// Only Read Allowed on this Register
+        /// </summary>
+        InputPort0 = 0x00,
+
+        /// <summary>
+        /// Register Adress for the Inputs P10 - P17
+        /// Only Read Allowed on this Register
+        /// </summary>
+        InputPort1 = 0x01,
+
+        /// <summary>
+        /// Register Adress for the Outputs P00 - P07
+        /// </summary>
+        OutputPort0 = 0x02,
+
+        /// <summary>
+        /// Register Adress for the Outputs P10 - P17
+        /// </summary>
+        OutputPort1 = 0x03,
+
+        /// <summary>
+        /// Register Adress for the Polarity Inversion P00 - P07
+        /// </summary>
+        PolarityInversionPort0 = 0x04,
+
+        /// <summary>
+        /// Register Adress for the Polarity Inversion P10 - P17
+        /// </summary>
+        PolarityInversionPort1 = 0x05,
+
+        /// <summary>
+        /// Register Adress for the Configuration P00 - P07
+        /// </summary>
+        ConfigurationPort0 = 0x06,
+
+        /// <summary>
+        /// Register Adress for the Configuration P10 - P17
+        /// </summary>
+        ConfigurationPort1 = 0x06,
+    }
+}