(* GPIO pin services using libsimpleio *)

(* Copyright (C)2018-2024, 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: *)
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(*   this list of conditions and the following disclaimer.                     *)
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DEFINITION MODULE GPIO_libsimpleio;

  IMPORT
    Channel;

  TYPE
    Pin;
    Direction = (Input, Output);
    Driver    = (PushPull, OpenDrain, OpenSource);
    Edge      = (None, Rising, Falling, Both);
    Polarity  = (ActiveLow, ActiveHigh);

  PROCEDURE Open
   (channel    : Channel.Designator;
    dir        : Direction;
    state      : BOOLEAN;
    driver     : Driver;
    edge       : Edge;
    polarity   : Polarity;
    VAR pin    : Pin;
    VAR error  : CARDINAL);

  PROCEDURE Close
   (VAR pin    : Pin;
    VAR error  : CARDINAL);

  PROCEDURE Read
   (pin        : Pin;
    VAR state  : BOOLEAN;
    VAR error  : CARDINAL);

  PROCEDURE Write
   (pin        : Pin;
    state      : BOOLEAN;
    VAR error  : CARDINAL);

  PROCEDURE fd(pin : Pin) : INTEGER;

END GPIO_libsimpleio.