1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
93 lines
2.3 KiB
C
93 lines
2.3 KiB
C
/*
|
|
* 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);
|
|
}
|