1/*
2 * lcd44780.c
3 * Simple "driver" for a memory-mapped 44780-style LCD display.
4 *
5 * Copyright 2001 Bradley D. LaRonde <brad@ltc.com>
6 *
7 * This program is free software; you can redistribute  it and/or modify it
8 * under  the terms of  the GNU General  Public License as published by the
9 * Free Software Foundation;  either version 2 of the  License, or (at your
10 * option) any later version.
11 *
12 */
13
14#define LCD44780_COMMAND   ((volatile unsigned char *)0xbe020000)
15#define LCD44780_DATA      ((volatile unsigned char *)0xbe020001)
16
17#define LCD44780_4BIT_1LINE        0x20
18#define LCD44780_4BIT_2LINE        0x28
19#define LCD44780_8BIT_1LINE        0x30
20#define LCD44780_8BIT_2LINE        0x38
21#define LCD44780_MODE_DEC          0x04
22#define LCD44780_MODE_DEC_SHIFT    0x05
23#define LCD44780_MODE_INC          0x06
24#define LCD44780_MODE_INC_SHIFT    0x07
25#define LCD44780_SCROLL_LEFT       0x18
26#define LCD44780_SCROLL_RIGHT      0x1e
27#define LCD44780_CURSOR_UNDERLINE  0x0e
28#define LCD44780_CURSOR_BLOCK      0x0f
29#define LCD44780_CURSOR_OFF        0x0c
30#define LCD44780_CLEAR             0x01
31#define LCD44780_BLANK             0x08
32#define LCD44780_RESTORE           0x0c  // Same as CURSOR_OFF
33#define LCD44780_HOME              0x02
34#define LCD44780_LEFT              0x10
35#define LCD44780_RIGHT             0x14
36
37void lcd44780_wait(void)
38{
39	int i, j;
40	for(i=0; i < 400; i++)
41		for(j=0; j < 10000; j++);
42}
43
44void lcd44780_command(unsigned char c)
45{
46	*LCD44780_COMMAND = c;
47	lcd44780_wait();
48}
49
50void lcd44780_data(unsigned char c)
51{
52	*LCD44780_DATA = c;
53	lcd44780_wait();
54}
55
56void lcd44780_puts(const char* s)
57{
58	int j;
59	int pos = 0;
60
61	lcd44780_command(LCD44780_CLEAR);
62	while(*s) {
63		lcd44780_data(*s);
64		s++;
65		pos++;
66		if (pos == 8) {
67		  /* We must write 32 of spaces to get cursor to 2nd line */
68		  for (j=0; j<32; j++) {
69		    lcd44780_data(' ');
70		  }
71		}
72		if (pos == 16) {
73		  /* We have filled all 16 character positions, so stop
74		     outputing data */
75		  break;
76		}
77	}
78#ifdef LCD44780_PUTS_PAUSE
79	{
80		int i;
81
82		for(i = 1; i < 2000; i++)
83			lcd44780_wait();
84	}
85#endif
86}
87
88void lcd44780_init(void)
89{
90	// The display on the RockHopper is physically a single
91	// 16 char line (two 8 char lines concatenated).  bdl
92	lcd44780_command(LCD44780_8BIT_2LINE);
93	lcd44780_command(LCD44780_MODE_INC);
94	lcd44780_command(LCD44780_CURSOR_BLOCK);
95	lcd44780_command(LCD44780_CLEAR);
96}
97