/**

	LS7266R1 Driver for Atmel AVR
	Daniel Beer and Tony Lloyd
	ECE 476

	Usage:
		#include "ls7266r1.h": Include the driver file
		LS_init(): Initialize the driver
		LS_write_RLD, LS_write_IOR, LS_write_CMR, LS_write_IDR(axis, value): Write control value to LS chip to 
				     axis. Axis can be select_X, select_Y or select_XY;
		LS_read_FLAG(axis): Read flag register value from axis. Axis can be select_X or select_Y.
		LS_read_output(axis): Read 24-bit output value from axis. Axis can be select_X or select_Y.
		LS_write_preset(axis, value): Write 24-bit preset register value to axis. Axis can be select_X, select_Y
								      or select_XY;
**/

#ifndef _LS7266R1_H_
#define _LS7266R1_H_
#pragma warn-

// ****************************************************************
//      LCD Setup
// ****************************************************************

// Data output port
#ifndef LS_data_out
#define LS_data_out PORTA
#endif

// Data input port
#ifndef LS_data_in
#define LS_data_in PINA
#endif

// Data ddr
#ifndef LS_data_ddr
#define LS_data_ddr DDRA
#endif

// Control output
#ifndef LS_ctrl_out
#define LS_ctrl_out PORTC
#endif

// Control ddr
#ifndef LS_ctrl_ddr
#define LS_ctrl_ddr DDRC
#endif

// Chip enable ddr
#ifndef LS_chipenable_ddr
#define LS_chipenable_ddr DDRC.3
#endif

// Chip enable output
#ifndef LS_chipenable_out
#define LS_chipenable_out PORTC.3
#endif

// ****************************************************************
//      Defines
// ****************************************************************

#define ctrl_mask 0b00001111
#define data_mask 0b00011111

#define chipenable_OFF 1
#define chipenable_ON 0

#define write_ctrl 0b01010000
#define write_data 0b00010000
#define ctrl_write_next 0b00100000
#define ctrl_chip_off 0b00110000

#define select_X 0b00000000
#define select_Y 0b01000000
#define select_XY 0b10000000

#define data_select_mask 0b10000000
#define ctrl_select_mask 0b01000000

#define read_ctrl 0b01100000
#define read_data 0b00100000
#define ctrl_read_next 0b00010000

#define addr_RLD 0b00000000
#define addr_CMR 0b00100000
#define addr_IOR 0b01000000
#define addr_IDR 0b01100000

#define RLD_reset_BP 0b00000001
#define RLD_reset_CNTR 0b00000010
#define RLD_reset_FLAGS 0b00000100
#define RLD_reset_E 0b00000110
#define RLD_trnsfr_PR 0b00001000
#define RLD_trnsfr_CNTR 0b00010000
#define RLD_trnsfr_PR0 0b00011000

#define IOR_enable_AB 0b00000001
#define IOR_LCNTR 0b00000000
#define IOR_LOL 0b00000010
#define IOR_RCNTR_ABgate 0b00000100

#define IDR_enable_index 0b00000001
#define IDR_positive_polarity 0b00000010
#define IDR_index_RCNTR 0b00000100

#define FLAG_BT 0x01
#define FLAG_CT 0x02
#define FLAG_CPT 0x04
#define FLAG_S 0x08
#define FLAG_E 0x10
#define FLAG_U 0x20
#define FLAG_ID 0x40

#define CMR_BCD 0x01
#define CMR_count_RANGE 0x02
#define CMR_count_NONRECYCLE 0x04
#define CMR_count_MODN 0x06
#define CMR_quad_X1 0x08
#define CMR_quad_X2 0x10
#define CMR_quad_X4 0x18

// ****************************************************************
//      Functions
// ****************************************************************

// Initialize the LS chip
// Cycles: 22
void LS_init(void)
{
	LS_ctrl_ddr = (LS_ctrl_ddr | 0xf0);
	LS_data_ddr = 0xff;
	LS_chipenable_ddr = 1;

	LS_ctrl_out = (LS_ctrl_out & ctrl_mask) | ctrl_chip_off;
}

// Write a byte to the LS chip
// Cycles: 79-86
void LS_write(unsigned char type, unsigned char addr, unsigned char XYselect, unsigned char data)
{
	LS_chipenable_out = chipenable_ON;

	LS_data_ddr = 0xff;
	if (type == write_ctrl)
		LS_data_out = (data & data_mask) | addr | (XYselect & data_select_mask);
	else
		LS_data_out = data;

	LS_ctrl_out = (LS_ctrl_out & ctrl_mask) | type | (XYselect & ctrl_select_mask);     
	
	#asm 
	  nop
	  nop
	  nop
	#endasm
	LS_ctrl_out |= ctrl_write_next;
	LS_ctrl_out = (LS_ctrl_out & ctrl_mask) | ctrl_chip_off;

	LS_chipenable_out = chipenable_OFF;
}

// Read a byte from the LS chip
// Cycles: 70
unsigned char LS_read(unsigned char type, unsigned char XYselect)
{
	unsigned char result;

	LS_chipenable_out = chipenable_ON;

	LS_data_ddr = 0x00;
	LS_data_out = 0x00;

	LS_ctrl_out = (LS_ctrl_out & ctrl_mask) | type | (XYselect & ctrl_select_mask);

	#asm 
	  nop
	  nop
	  nop
	#endasm

	result = LS_data_in;
	LS_ctrl_out |= ctrl_read_next;
	LS_ctrl_out = (LS_ctrl_out & ctrl_mask) | ctrl_chip_off;

	LS_chipenable_out = chipenable_OFF;

	return result;
}

// Read a 24-bit value from the LS chip
// Cycles: 392
signed long int LS_read_output(unsigned char XYselect)
{
	unsigned long int result;
	LS_write(write_ctrl, addr_RLD, XYselect, RLD_reset_BP | RLD_trnsfr_CNTR);
	result = LS_read(read_data, XYselect);
	result += (unsigned int)(LS_read(read_data, XYselect)) << 8;
	result += (signed long int)(LS_read(read_data, XYselect)) << 16; 
	result += (signed long int)((result & 0x00800000)? 0xff000000 : 0x00000000);

	return result;
}

// Write a 24-bit value to the LS chip
// Cycles: 370
void LS_write_preset(unsigned char XYselect, signed long int preset)
{
	LS_write(write_ctrl, addr_RLD, XYselect, RLD_reset_BP);
	LS_write(write_data, 0, XYselect, (unsigned char) (preset & 0xff));
	LS_write(write_data, 0, XYselect, (unsigned char) ((preset >> 8)& 0xff));
	LS_write(write_data, 0, XYselect, (unsigned char) ((preset >> 16)& 0xff));
}

// Read the flag register
#define LS_read_flag(XYselect) LS_read(read_data, XYselect)

// Write the preset register
#define LS_write_PRS(XYselect, data) LS_write(write_data, 0, XYselect, data)

// Write the RLD register
#define LS_write_RLD(XYselect, data) LS_write(write_ctrl, addr_RLD, XYselect, data)

// Write the CMR register
#define LS_write_CMR(XYselect, data) LS_write(write_ctrl, addr_CMR, XYselect, data)

// Write the IOR register
#define LS_write_IOR(XYselect, data) LS_write(write_ctrl, addr_IOR, XYselect, data)

// Write the IDR register
#define LS_write_IDR(XYselect, data) LS_write(write_ctrl, addr_IDR, XYselect, data)

#pragma warn+
#endif