unit m.iic;

interface
uses
   m.base,
   m.iic.types;

type
   TmodIIC = class( TmodBase, IIIC)
      protected
         function Wait(    addr     : word;
                           tmo      : word = 100): TIICStatus;

         function Write(   addr     : word;
                           count    : byte;
                           buffer   : pointer;
                           tmo      : word = 100): TIICStatus;

         function Read(    addr     : word;
                           count    : byte;
                           buffer   : pointer;
                           tmo      : word = 100): TIICStatus;

         function ReadRSW( addr     : word;
                           subaddr  : word;
                           count    : byte;
                           buffer   : pointer;
                           tmo      : word = 100): TIICStatus;
   end;


implementation
uses
   windows, math,
   mr.dev.usb.pipe;


function CyWORD( value: word): word; overload;
begin
   result := (LoByte(value) shl 8) or HiByte(value);
end;

function CyWORD( value: byte): word; overload;
begin
   result := value shl 8;
end;



{ TmodIIC }

// @@@: IIIC ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//
//                                             IIIC
//
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// ================================================================================================
// wait
// ================================================================================================
function TmodIIC.Wait(addr: word; tmo: word): TIICStatus;
begin
   result := IIC_TMO;

end;

// ================================================================================================
// write
// ================================================================================================
function TmodIIC.Write(addr: word; count: byte; buffer: pointer; tmo: word): TIICStatus;
var
   buf: TIICPacket;
   len: cardinal;

   p01: TPipe;
   p81: TPipe;

begin
   result := IIC_TMO;

   if Assigned(fDevice) then
   begin
      p01 := fDevice.Pipes[$01];
      p81 := fDevice.Pipes[$81];

      if Assigned(p01) and Assigned(p81) then
      begin
         FillChar( buf, sizeof(buf), 0);

         buf.head.command  := IIC_WRITE;
         buf.head.timeout  := tmo;
         buf.head.address  := CyWORD(addr);
         buf.head.length   := min(count, 32);

         MoveMemory(@buf.data[0], buffer, buf.head.length);

         p01.Write(  buf, sizeof( TIICPacket),     len);
         p81.Read(   buf, sizeof( TIICPacketHead), len)
      end
   end
end;

// ================================================================================================
// read
// ================================================================================================
function TmodIIC.Read(addr: word; count: byte; buffer: pointer; tmo: word): TIICStatus;
var
   buf: TIICPacket;
   len: cardinal;

   p01: TPipe;
   p81: TPipe;

begin
   result := IIC_TMO;

   if Assigned(fDevice) then
   begin
      p01 := fDevice.Pipes[$01];
      p81 := fDevice.Pipes[$81];

      if Assigned(p01) and Assigned(p81) then
      begin
         FillChar( buf, sizeof(buf), 0);

         buf.head.command  := IIC_READ;
         buf.head.timeout  := tmo;
         buf.head.address  := CyWORD(addr);
         buf.head.length   := min(count, 32);

         if p01.Write( buf, sizeof( TIICPacketHead), len) then
         begin
            p81.Read(  buf, sizeof( TIICPacket), len);

            result := TIICStatus(buf.head.timeout);

            if result = IIC_OK then
               MoveMemory(buffer, @buf.data[0], buf.head.length)
         end;

      end
   end
end;

// ================================================================================================
// read with repeated start condition, 16 bit sub address
// ================================================================================================
function TmodIIC.ReadRSW(addr: word; subaddr: word; count: byte; buffer: pointer; tmo: word): TIICStatus;
var
   buf: TIICPacket;
   len: cardinal;

   p01: TPipe;
   p81: TPipe;

begin
   result := IIC_TMO;

   if Assigned(fDevice) then
   begin
      p01 := fDevice.Pipes[$01];
      p81 := fDevice.Pipes[$81];

      if Assigned(p01) and Assigned(p81) then
      begin
         FillChar( buf, sizeof(buf), 0);

         buf.head.command  := IIC_READ_RSW;
         buf.head.timeout  := tmo;
         buf.head.address  := CyWORD(addr);
         buf.head.subaddr  := CyWORD(subaddr);
         buf.head.length   := min(count, 32);

         p01.Write(  buf, sizeof( TIICPacketHead), len);
         p81.Read(   buf, sizeof( TIICPacket),     len);

         MoveMemory(buffer, @buf.data[0], buf.head.length)
      end
   end
end;

end.