/*

Written by Holguer A. Becerra,
Students: Andrea Paola Pabón Ortega & Daniel Enrique Mejia Rueda
Description: Enhanced Verilog driver for chip XPT2046
*/

module touch(

      ///// ADC SPI CONTROLLER
      CLOCK_50, 
		reset_n, 
		TFT_ADC_DIN, 
		TFT_ADC_DCLK, 
		TFT_ADC_CS_N, 
		TFT_ADC_DOUT, 
		TFT_ADC_BUSY, 
		TFT_ADC_PENIRQ_N,
		
      real_x, 
		real_y, 
		CLK_2KHz, 
		PEN_DOWN);
		
//=======================================================
//  PORT declarations
//=======================================================

///// ADC SPI CONTROLLER
input       CLOCK_50;
input 		reset_n; 
output		TFT_ADC_DIN; 
output		TFT_ADC_DCLK; 
output		TFT_ADC_CS_N; 
input	   	TFT_ADC_DOUT; 
input	      TFT_ADC_BUSY; 
input	   	TFT_ADC_PENIRQ_N;


output [31:0]        real_x;
output [31:0]     	real_y; 
input                CLK_2KHz; 
output          		PEN_DOWN;

/////////////// TOUCH ///////////////////
//// si funciona esto deberias meter esta parte del touch toda en un solo modulo... desde aqui hasta
////Touch
localparam X_ADC_UPPER_RIGTH=3975;
localparam X_POS_UPPER_RIGTH=479;
localparam X_ADC_LOWER_LEFT=112;
localparam X_POS_LOWER_LEFT=0;

localparam Y_ADC_UPPER_RIGTH=4032;
localparam Y_POS_UPPER_RIGTH=0;
localparam Y_ADC_LOWER_LEFT=110;
localparam Y_POS_LOWER_LEFT=271;

wire [11:0]  x_coord;
wire [11:0]  y_coord;
wire new_coord; 
 
adc_spi_controller u2 (
 .iCLK(CLOCK_50), //in
 .iRST_n(reset_n), //in
 .oADC_DIN(TFT_ADC_DIN), //out
 .oADC_DCLK(TFT_ADC_DCLK),//out
 .oADC_CS(TFT_ADC_CS_N),//out
 .iADC_DOUT(TFT_ADC_DOUT),//in
 .iADC_BUSY(TFT_ADC_BUSY),// in
 .iADC_PENIRQ_n(TFT_ADC_PENIRQ_N),//in
 .oX_COORD(x_coord),//out 12bits
 .oY_COORD(y_coord),//out 12 bits
 .oNEW_COORD(new_coord),//out
  );
  
wire [31:0] numeratorX=(y_coord-X_ADC_LOWER_LEFT)*(X_POS_UPPER_RIGTH-X_POS_LOWER_LEFT);
wire [31:0] denominatorX=X_ADC_UPPER_RIGTH-X_ADC_LOWER_LEFT; 
reg [31:0] real_x;


wire [31:0] numeratorY=(x_coord-Y_ADC_LOWER_LEFT)*(Y_POS_LOWER_LEFT-Y_POS_UPPER_RIGTH);
wire [31:0] denominatorY=Y_ADC_UPPER_RIGTH-Y_ADC_LOWER_LEFT; 
reg [31:0] real_y;

wire CLK_2KHz;
localparam DELAY=200;

reg [DELAY-1:0]TFT_ADC_PENIRQ_N_delayed;
reg valid_touch=1'b1;
wire PEN_DOWN=TFT_ADC_PENIRQ_N_delayed[DELAY-1];

genvar index;
generate
for(index=0; index<DELAY; index=index+1)
	begin: retreso
		if(index==0)
		begin
			always@(posedge CLK_2KHz)
			begin
				TFT_ADC_PENIRQ_N_delayed[index]<=TFT_ADC_PENIRQ_N;
			end

		end
		else
		begin
			always@(posedge CLK_2KHz)
			begin
				TFT_ADC_PENIRQ_N_delayed[index]<=TFT_ADC_PENIRQ_N_delayed[index-1];
			end
		end
	end
endgenerate

//
//assign LED[0]=TFT_ADC_PENIRQ_N;
//assign LED[1]=PEN_DOWN;


always@(negedge CLOCK_50)
begin
 real_y<=real_y;
 real_x<=real_x;
 valid_touch<=1'b1;
 if(!TFT_ADC_PENIRQ_N_delayed[DELAY-1])
 begin
	 valid_touch<=1'b0;
	 real_y<= Y_POS_LOWER_LEFT-(numeratorY/denominatorY);
	 real_x<= (numeratorX/denominatorX)+X_POS_LOWER_LEFT;
 end 
end

//// aqui


endmodule