-- MCP23x17 I2C GPIO expander 16-bit parallel port services

-- Copyright (C)2017-2023, Philip Munts dba Munts Technologies.
--
-- Redistribution and use in source and binary forms, with or without
-- modification, are permitted provided that the following conditions are met:
--
-- * Redistributions of source code must retain the above copyright notice,
--   this list of conditions and the following disclaimer.
--
-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-- IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-- ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
-- LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
-- CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
-- SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-- INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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-- POSSIBILITY OF SUCH DAMAGE.

PACKAGE BODY MCP23x17.Word IS

  -- Parallel port constructor

  FUNCTION Create(dev : NOT NULL MCP23x17.Device) RETURN Port IS

  BEGIN
    RETURN NEW PortClass'(dev => dev);
  END Create;

  -- Parallel port configuration methods

  PROCEDURE SetDirections(Self : PortClass; data : Word) IS

  -- data: 1=output, 0=input

  BEGIN
    Self.dev.WriteRegister16(IODIR, NOT RegisterData16(data));
  END SetDirections;

  PROCEDURE SetPullups(Self : PortClass; data : Word) IS

  -- data: 1=pullup enabled, 0=pullup disabled

  BEGIN
    Self.dev.WriteRegister16(GPPU, RegisterData16(data));
  END SetPullups;

  -- Parallel port I/O methods

  PROCEDURE Put(Self : PortClass; data : Word) IS

  BEGIN
    Self.dev.WriteRegister16(GPIOLAT, RegisterData16(data));
  END Put;

  FUNCTION Get(Self : PortClass) RETURN Word IS

    data : RegisterData16;

  BEGIN
    Self.dev.ReadRegister16(GPIODAT, data);

    RETURN Word(data);
  END Get;

END MCP23x17.Word;