// This header contains low level code to export from hd44780.c to "lower" HW
// implementation dependent files.

#ifndef HD_LOW_H
#define HD_LOW_H

enum ifWidth { IF_4bit, IF_8bit };

void common_init (enum ifWidth ifwidth);

// Structures holding pointers to HD44780 specific functions
typedef struct hwDependentFns {
	// microsec pauses
	void (*uPause) (int microSecondsTenths);

	// senddata to the LCD
	// dispID     - display to send data to (0 = all displays)
	// flags      - data or instruction command (RS_DATA | RS_INSTR)
	// ch         - character to display or instruction value
	void (*senddata) (unsigned char dispID, unsigned char flags, unsigned char ch);

	// position the cursor
	// dispID     - display to send data to (0 = all displays)
	// DDaddr     - display data address (see sect 2.5.2 of the LCD module FAQ)
	void (*position) (int dispID, int DDaddr);

	// toggle vertical autoscroll on all displays
	// on         - non-zero turns autoscroll on, zero value turns it off
	void (*autoscroll) (int on);
} HD44780_functions;				  /* for want of a better name :-) */

extern HD44780_functions *hd44780_functions;

// commands for senddata
#define RS_DATA     0x00
#define RS_INSTR    0x01

#define CLEAR       0x01

#define HOMECURSOR  0x02

#define ENTRYMODE   0x04
#define E_MOVERIGHT 0x02
#define E_MOVELEFT  0x00
#define EDGESCROLL  0x01
#define NOSCROLL    0x00

#define ONOFFCTRL   0x08
#define DISPON      0x04
#define DISPOFF     0x00
#define CURSORON    0x02
#define CURSOROFF   0x00
#define CURSORBLINK 0x01
#define CURSORNOBLINK 0x00

#define CURSORSHIFT 0x10
#define SCROLLDISP  0x08
#define MOVECURSOR  0x00
#define MOVERIGHT   0x04
#define MOVELEFT    0x00

#define FUNCSET     0x20
#define IF_8BIT     0x10
#define IF_4BIT     0x00
#define TWOLINE     0x08
#define ONELINE     0x00
#define LARGECHAR   0x04		  /* 5x11 characters */
#define SMALLCHAR   0x00		  /* 5x8 characters */

#define SETCHAR     0x40

#define POSITION    0x80

// Parallel port pin definitions
// Output lines
#define nSTRB 	0x01				  /* negative logic */
#define STRB 	0x01
#define nLF 	0x02
#define LF 	0x02
#define INIT 	0x04				  /* the only positive logic output line */
#define nSEL 	0x08
#define SEL 	0x08

#define OUTMASK	0x0B

// Input lines
#define nFAULT	0x08
#define FAULT	0x08
#define SELIN	0x10
#define PAPEREND  0x20
#define nACK	0x40
#define ACK	0x40
#define BUSY	0x80

#define INMASK	0x48

#endif