/*

  This Source Code Form is subject to the terms of the Mozilla Public

  License, v. 2.0. If a copy of the MPL was not distributed with this

  file, You can obtain one at http://mozilla.org/MPL/2.0/.

  Copyright (C) 2009-2012 Michael Möller <mmoeller@openhardwaremonitor.org>

*/

using System.Globalization;

using System.Text;

namespace OpenHardwareMonitor.Hardware.LPC {

  internal class IT87XX : ISuperIO {

    private readonly ushort address;

    private readonly Chip chip;

    private readonly byte version;

    private readonly ushort gpioAddress;

    private readonly int gpioCount;

    private readonly ushort addressReg;

    private readonly ushort dataReg;

    private readonly float?[] voltages = new float?[0];

    private readonly float?[] temperatures = new float?[0];

    private readonly float?[] fans = new float?[0];

    private readonly float?[] controls = new float?[0];

    private readonly float voltageGain;

    private readonly bool has16bitFanCounter;

    // Consts

    private const byte ITE_VENDOR_ID = 0x90;

    // Environment Controller

    private const byte ADDRESS_REGISTER_OFFSET = 0x05;

    private const byte DATA_REGISTER_OFFSET = 0x06;

    // Environment Controller Registers    

    private const byte CONFIGURATION_REGISTER = 0x00;

    private const byte TEMPERATURE_BASE_REG = 0x29;

    private const byte VENDOR_ID_REGISTER = 0x58;

    private const byte FAN_TACHOMETER_DIVISOR_REGISTER = 0x0B;

    private readonly byte[] FAN_TACHOMETER_REG = 

      new byte[] { 0x0d, 0x0e, 0x0f, 0x80, 0x82 };

    private readonly byte[] FAN_TACHOMETER_EXT_REG =

      new byte[] { 0x18, 0x19, 0x1a, 0x81, 0x83 };

    private const byte VOLTAGE_BASE_REG = 0x20;

    private byte ReadByte(byte register, out bool valid) {

      Ring0.WriteIoPort(addressReg, register);

      byte value = Ring0.ReadIoPort(dataReg);

      valid = register == Ring0.ReadIoPort(addressReg);

      return value;

    }

    private bool WriteByte(byte register, byte value) {

      Ring0.WriteIoPort(addressReg, register);

      Ring0.WriteIoPort(dataReg, value);

      return register == Ring0.ReadIoPort(addressReg); 

    }

    public byte? ReadGPIO(int index) {

      if (index >= gpioCount)

        return null;

      return Ring0.ReadIoPort((ushort)(gpioAddress + index));

    }

    public void WriteGPIO(int index, byte value) {

      if (index >= gpioCount)

        return;

      Ring0.WriteIoPort((ushort)(gpioAddress + index), value);

    } 

    public void SetControl(int index, byte? value) { }   

    public IT87XX(Chip chip, ushort address, ushort gpioAddress, byte version) {

      this.address = address;

      this.chip = chip;

      this.version = version;

      this.addressReg = (ushort)(address + ADDRESS_REGISTER_OFFSET);

      this.dataReg = (ushort)(address + DATA_REGISTER_OFFSET);

      this.gpioAddress = gpioAddress;

      // Check vendor id

      bool valid;

      byte vendorId = ReadByte(VENDOR_ID_REGISTER, out valid);       

      if (!valid || vendorId != ITE_VENDOR_ID)

        return;

      // Bit 0x10 of the configuration register should always be 1

      if ((ReadByte(CONFIGURATION_REGISTER, out valid) & 0x10) == 0)

        return;

      if (!valid)

        return;

      voltages = new float?[9];

      temperatures = new float?[3];

      fans = new float?[chip == Chip.IT8705F ? 3 : 5];

      // IT8721F, IT8728F and IT8772E use a 12mV resultion ADC, all others 16mV

      if (chip == Chip.IT8721F || chip == Chip.IT8728F || chip == Chip.IT8771E 

        || chip == Chip.IT8772E) 

      {

        voltageGain = 0.012f;

      } else {

        voltageGain = 0.016f;        

      }

      // older IT8705F and IT8721F revisions do not have 16-bit fan counters

      if ((chip == Chip.IT8705F && version < 3) || 

          (chip == Chip.IT8712F && version < 8)) 

      {

        has16bitFanCounter = false;

      } else {

        has16bitFanCounter = true;

      }

      // Set the number of GPIO sets

      switch (chip) {

        case Chip.IT8712F:

        case Chip.IT8716F:

        case Chip.IT8718F:

        case Chip.IT8726F:

          gpioCount = 5;

          break;

        case Chip.IT8720F:

        case Chip.IT8721F:

          gpioCount = 8;

          break;

        case Chip.IT8705F: 

        case Chip.IT8728F:

        case Chip.IT8771E:

        case Chip.IT8772E:

          gpioCount = 0;

          break;

      }

    }

    public Chip Chip { get { return chip; } }

    public float?[] Voltages { get { return voltages; } }

    public float?[] Temperatures { get { return temperatures; } }

    public float?[] Fans { get { return fans; } }

    public float?[] Controls { get { return controls; } }

    public string GetReport() {

      StringBuilder r = new StringBuilder();

      r.AppendLine("LPC " + this.GetType().Name);

      r.AppendLine();

      r.Append("Chip ID: 0x"); r.AppendLine(chip.ToString("X"));

      r.Append("Chip Version: 0x"); r.AppendLine(

        version.ToString("X", CultureInfo.InvariantCulture));

      r.Append("Base Address: 0x"); r.AppendLine(

        address.ToString("X4", CultureInfo.InvariantCulture));

      r.Append("GPIO Address: 0x"); r.AppendLine(

        gpioAddress.ToString("X4", CultureInfo.InvariantCulture));

      r.AppendLine();

      if (!Ring0.WaitIsaBusMutex(100))

        return r.ToString();

      r.AppendLine("Environment Controller Registers");

      r.AppendLine();

      r.AppendLine("      00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F");

      r.AppendLine();

      for (int i = 0; i <= 0xA; i++) {

        r.Append(" "); 

        r.Append((i << 4).ToString("X2", CultureInfo.InvariantCulture)); 

        r.Append("  ");

        for (int j = 0; j <= 0xF; j++) {

          r.Append(" ");

          bool valid;

          byte value = ReadByte((byte)((i << 4) | j), out valid);

          r.Append(

            valid ? value.ToString("X2", CultureInfo.InvariantCulture) : "??");

        }

        r.AppendLine();

      }

      r.AppendLine();

      r.AppendLine("GPIO Registers");

      r.AppendLine();

      for (int i = 0; i < gpioCount; i++) {

        r.Append(" ");

        r.Append(ReadGPIO(i).Value.ToString("X2",

          CultureInfo.InvariantCulture));

      }

      r.AppendLine();

      r.AppendLine();

      Ring0.ReleaseIsaBusMutex();

      return r.ToString();

    }

    public void Update() {

      if (!Ring0.WaitIsaBusMutex(10))

        return;

      for (int i = 0; i < voltages.Length; i++) {

        bool valid;

        float value = 

          voltageGain * ReadByte((byte)(VOLTAGE_BASE_REG + i), out valid);   

        if (!valid)

          continue;

        if (value > 0)

          voltages[i] = value;  

        else

          voltages[i] = null;

      }

      for (int i = 0; i < temperatures.Length; i++) {

        bool valid;

        sbyte value = (sbyte)ReadByte(

          (byte)(TEMPERATURE_BASE_REG + i), out valid);

        if (!valid)

          continue;

        if (value < sbyte.MaxValue && value > 0)

          temperatures[i] = value;

        else

          temperatures[i] = null;       

      }

      if (has16bitFanCounter) {

        for (int i = 0; i < fans.Length; i++) {

          bool valid;

          int value = ReadByte(FAN_TACHOMETER_REG[i], out valid);

          if (!valid)

            continue;

          value |= ReadByte(FAN_TACHOMETER_EXT_REG[i], out valid) << 8;

          if (!valid)

            continue;

          if (value > 0x3f) {

            fans[i] = (value < 0xffff) ? 1.35e6f / (value * 2) : 0;

          } else {

            fans[i] = null;

          }

        }

      } else {

        for (int i = 0; i < fans.Length; i++) {

          bool valid;

          int value = ReadByte(FAN_TACHOMETER_REG[i], out valid);

          if (!valid)

            continue;

          int divisor = 2;

          if (i < 2) {

            int divisors = ReadByte(FAN_TACHOMETER_DIVISOR_REGISTER, out valid);

            if (!valid)

              continue;

            divisor = 1 << ((divisors >> (3 * i)) & 0x7);

          }

          if (value > 0) {

            fans[i] = (value < 0xff) ? 1.35e6f / (value * divisor) : 0;

          } else {

            fans[i] = null;

          }

        }

      }

      Ring0.ReleaseIsaBusMutex();

    }

  } 

}