// ***************************************************************************
// ***************************************************************************
// Copyright 2013(c) Analog Devices, Inc.
//  Author: Lars-Peter Clausen <lars@metafoo.de>
// 
// All rights reserved.
// 
// 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.
//     - Redistributions in binary form must reproduce the above copyright
//       notice, this list of conditions and the following disclaimer in
//       the documentation and/or other materials provided with the
//       distribution.
//     - Neither the name of Analog Devices, Inc. nor the names of its
//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//     - The use of this software may or may not infringe the patent rights
//       of one or more patent holders.  This license does not release you
//       from the requirement that you obtain separate licenses from these
//       patent holders to use this software.
//     - Use of the software either in source or binary form, must be run
//       on or directly connected to an Analog Devices Inc. component.
//    
// THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
// INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A
// PARTICULAR PURPOSE ARE DISCLAIMED.
//
// IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, INTELLECTUAL PROPERTY
// RIGHTS, 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 CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// ***************************************************************************
// ***************************************************************************

module dmac_src_axi_stream (
  input s_axis_aclk,
  input s_axis_aresetn,

  input enable,
  output enabled,
  input sync_id,
  output sync_id_ret,

  input [ID_WIDTH-1:0] request_id,
  output [ID_WIDTH-1:0] response_id,
  input eot,

  output s_axis_ready,
  input s_axis_valid,
  input [S_AXIS_DATA_WIDTH-1:0] s_axis_data,
  input [0:0] s_axis_user,
  output s_axis_xfer_req,

  input fifo_ready,
  output fifo_valid,
  output [S_AXIS_DATA_WIDTH-1:0] fifo_data,

  input req_valid,
  output req_ready,
  input [BEATS_PER_BURST_WIDTH-1:0] req_last_burst_length,
  input req_sync_transfer_start
);

parameter ID_WIDTH = 3;
parameter S_AXIS_DATA_WIDTH = 64;
parameter LENGTH_WIDTH = 24;
parameter BEATS_PER_BURST_WIDTH = 4;

reg needs_sync = 1'b0;
wire sync = s_axis_user[0];
wire has_sync = ~needs_sync | sync;
wire sync_valid = s_axis_valid & has_sync;
assign sync_id_ret = sync_id;

always @(posedge s_axis_aclk)
begin
  if (s_axis_aresetn == 1'b0) begin
    needs_sync <= 1'b0;
  end else begin
    if (s_axis_valid && s_axis_ready && sync) begin
      needs_sync <= 1'b0;
    end else if (req_valid && req_ready) begin
      needs_sync <= req_sync_transfer_start;
    end
  end
end

dmac_data_mover # (
  .ID_WIDTH(ID_WIDTH),
  .DATA_WIDTH(S_AXIS_DATA_WIDTH),
  .DISABLE_WAIT_FOR_ID(0),
  .BEATS_PER_BURST_WIDTH(BEATS_PER_BURST_WIDTH)
) i_data_mover (
  .clk(s_axis_aclk),
  .resetn(s_axis_aresetn),

  .enable(enable),
  .enabled(enabled),
  .sync_id(sync_id),

  .xfer_req(s_axis_xfer_req),

  .request_id(request_id),
  .response_id(response_id),
  .eot(eot),
  
  .req_valid(req_valid),
  .req_ready(req_ready),
  .req_last_burst_length(req_last_burst_length),

  .s_axi_ready(s_axis_ready),
  .s_axi_valid(sync_valid),
  .s_axi_data(s_axis_data),
  .m_axi_ready(fifo_ready),
  .m_axi_valid(fifo_valid),
  .m_axi_data(fifo_data)
);

endmodule
