/*--------------------------------------------------------------------------
 * LCD routines based on HD44780U standard
 * Texas Intruments MSC12xx MCU family chips
 *
 * Written By - Philippe Latu / philippe.latu(at)linux-france.org
 * $Id: lcd_msc1210.h 1126 2007-05-06 21:58:55Z latu $
 * 
 * Copyright (C) 2007  Philippe Latu
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNES0S FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 *---------------------------------------------------------------------------*/

#ifndef __LCD_MSC1210_H
#define __LCD_MSC1210_H

// Device addressing
// Addresses are hardware dependant and should be changed to fit
// hardware requirements
sbit at 0xb6 LCD_READ_WRITE;
sbit at 0xb5 LCD_REGISTER_SELECT;
sbit at 0xb7 LCD_ENABLE;
sfr  at 0x80 LCD_DATA;

// Device commands
// Commands defined from HD44780U standard
#define LCD_CLEAR_CMD	0x01
#define LCD_HOME_CMD	0x02
#define LCD_ON_CMD	0x0c
#define LCD_SHIFT_CMD	0x10
#define LCD_CONFIG_CMD	0x38

// Cursor positionning
// starting from 0,0
#define LCD_DSPL_WIDTH	0x14
#define LCD_DSPL_HEIGHT	0x04
#define LCD_ADDR_OFFSET	0x40

#define lcd_set_xy(x, y) (lcd_command( ( (y%LCD_DSPL_HEIGHT == 0) || (y%LCD_DSPL_HEIGHT == 2) ? (y%LCD_DSPL_HEIGHT/2 * LCD_DSPL_WIDTH + x%LCD_DSPL_WIDTH) : ((y%LCD_DSPL_HEIGHT-1)/2 * LCD_DSPL_WIDTH + LCD_ADDR_OFFSET + x%LCD_DSPL_WIDTH) ) | 0x80))

// Display selection boolean parameter
// print2lcd = 0: serial line
// print2lcd = 1: LCD
bit print2lcd = 0;

void lcd_busy(void) {
	do {
		LCD_ENABLE = 0;          // start
		LCD_REGISTER_SELECT = 0; // command mode
		LCD_READ_WRITE = 1;      // read
		LCD_DATA = 0xff;         // every data bits to 1
		LCD_ENABLE = 1;          // send
	} while (LCD_DATA & 0x80);	 // get LCD status

	LCD_ENABLE = 0;			 // cleanup before leaving
	LCD_READ_WRITE = 0;
}

void lcd_command(unsigned char cmd) {
	lcd_busy();
	LCD_ENABLE = 0;			 // start
	LCD_REGISTER_SELECT = 0;	 // command mode
	LCD_READ_WRITE = 0;		 // write
	LCD_DATA = cmd;			 // instruction
	LCD_ENABLE = 1;			 // send
	LCD_ENABLE = 0;			 // cleanup before leaving
}

void lcd_putc(unsigned char c) {
	lcd_busy();
	LCD_ENABLE = 0;			 // start
	LCD_REGISTER_SELECT = 1;	 // data mode
	LCD_READ_WRITE = 0;		 // write
	LCD_DATA = c;			 // character to display
	LCD_ENABLE = 1;			 // send
	LCD_ENABLE = 0;			 // cleanup before leaving
}

void lcd_init(void) {
	lcd_command(LCD_CONFIG_CMD);
	lcd_command(LCD_ON_CMD);
	lcd_command(LCD_SHIFT_CMD);
}

void lcd_clear(void) {
	lcd_command(LCD_CLEAR_CMD);
}

void lcd_home(void) {
	lcd_command(LCD_HOME_CMD);
}

#endif