text: /*
   * lcd44780.c
   * Simple "driver" for a memory-mapped 44780-style LCD display.
   *
   * Copyright 2001 Bradley D. LaRonde <brad@ltc.com>
   *
   * This program is free software; you can redistribute  it and/or modify it
   * under  the terms of  the GNU General  Public License as published by the
   * Free Software Foundation;  either version 2 of the  License, or (at your
   * option) any later version.
   *
   */
  
  #define LCD44780_COMMAND   ((volatile unsigned char *)0xbe020000)
  #define LCD44780_DATA      ((volatile unsigned char *)0xbe020001)
  
  #define LCD44780_4BIT_1LINE        0x20
  #define LCD44780_4BIT_2LINE        0x28
  #define LCD44780_8BIT_1LINE        0x30
  #define LCD44780_8BIT_2LINE        0x38
  #define LCD44780_MODE_DEC          0x04
  #define LCD44780_MODE_DEC_SHIFT    0x05
  #define LCD44780_MODE_INC          0x06
  #define LCD44780_MODE_INC_SHIFT    0x07
  #define LCD44780_SCROLL_LEFT       0x18
  #define LCD44780_SCROLL_RIGHT      0x1e
  #define LCD44780_CURSOR_UNDERLINE  0x0e
  #define LCD44780_CURSOR_BLOCK      0x0f
  #define LCD44780_CURSOR_OFF        0x0c
  #define LCD44780_CLEAR             0x01
  #define LCD44780_BLANK             0x08
  #define LCD44780_RESTORE           0x0c  // Same as CURSOR_OFF
  #define LCD44780_HOME              0x02
  #define LCD44780_LEFT              0x10
  #define LCD44780_RIGHT             0x14
  
  void lcd44780_wait(void)
  {
  	int i, j;
  	for(i=0; i < 400; i++)
  		for(j=0; j < 10000; j++);
  }
  
  void lcd44780_command(unsigned char c)
  {
  	*LCD44780_COMMAND = c;
  	lcd44780_wait();
  }
  
  void lcd44780_data(unsigned char c)
  {
  	*LCD44780_DATA = c;
  	lcd44780_wait();
  }
  
  void lcd44780_puts(const char* s)
  {
  	int i,j;
  	int pos = 0;
  
  	lcd44780_command(LCD44780_CLEAR);
  	while(*s) {
  		lcd44780_data(*s);
  		s++;
  		pos++;
  		if (pos == 8) {
  		  /* We must write 32 of spaces to get cursor to 2nd line */
  		  for (j=0; j<32; j++) {
  		    lcd44780_data(' ');
  		  }
  		}
  		if (pos == 16) {
  		  /* We have filled all 16 character positions, so stop
  		     outputing data */
  		  break;
  		}
  	}
  #ifdef LCD44780_PUTS_PAUSE
  	for(i = 1; i < 2000; i++)
  		lcd44780_wait();
  #endif
  }
  
  void lcd44780_init(void)
  {
  	// The display on the RockHopper is physically a single
  	// 16 char line (two 8 char lines concatenated).  bdl
  	lcd44780_command(LCD44780_8BIT_2LINE);
  	lcd44780_command(LCD44780_MODE_INC);
  	lcd44780_command(LCD44780_CURSOR_BLOCK);
  	lcd44780_command(LCD44780_CLEAR);
  }
  