diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/mips/ddb5xxx/ddb5477/lcd44780.c |
Linux-2.6.12-rc2
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!
Diffstat (limited to 'arch/mips/ddb5xxx/ddb5477/lcd44780.c')
-rw-r--r-- | arch/mips/ddb5xxx/ddb5477/lcd44780.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/arch/mips/ddb5xxx/ddb5477/lcd44780.c b/arch/mips/ddb5xxx/ddb5477/lcd44780.c new file mode 100644 index 00000000000..35c6c22610c --- /dev/null +++ b/arch/mips/ddb5xxx/ddb5477/lcd44780.c @@ -0,0 +1,92 @@ +/* + * 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); +} |