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Diffstat (limited to 'arch/mips/ddb5xxx/ddb5477/lcd44780.c')
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diff --git a/arch/mips/ddb5xxx/ddb5477/lcd44780.c b/arch/mips/ddb5xxx/ddb5477/lcd44780.c
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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 i,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 for(i = 1; i < 2000; i++)
80 lcd44780_wait();
81#endif
82}
83
84void lcd44780_init(void)
85{
86 // The display on the RockHopper is physically a single
87 // 16 char line (two 8 char lines concatenated). bdl
88 lcd44780_command(LCD44780_8BIT_2LINE);
89 lcd44780_command(LCD44780_MODE_INC);
90 lcd44780_command(LCD44780_CURSOR_BLOCK);
91 lcd44780_command(LCD44780_CLEAR);
92}