linux/arch/xtensa/platforms/xtfpga/lcd.c

77 lines
1.6 KiB
C

/*
* Driver for the LCD display on the Tensilica LX60 Board.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001, 2006 Tensilica Inc.
*/
/*
*
* FIXME: this code is from the examples from the LX60 user guide.
*
* The lcd_pause function does busy waiting, which is probably not
* great. Maybe the code could be changed to use kernel timers, or
* change the hardware to not need to wait.
*/
#include <linux/init.h>
#include <linux/io.h>
#include <platform/hardware.h>
#include <platform/lcd.h>
#include <linux/delay.h>
#define LCD_PAUSE_ITERATIONS 4000
#define LCD_CLEAR 0x1
#define LCD_DISPLAY_ON 0xc
/* 8bit and 2 lines display */
#define LCD_DISPLAY_MODE8BIT 0x38
#define LCD_DISPLAY_POS 0x80
#define LCD_SHIFT_LEFT 0x18
#define LCD_SHIFT_RIGHT 0x1c
static int __init lcd_init(void)
{
*LCD_INSTR_ADDR = LCD_DISPLAY_MODE8BIT;
mdelay(5);
*LCD_INSTR_ADDR = LCD_DISPLAY_MODE8BIT;
udelay(200);
*LCD_INSTR_ADDR = LCD_DISPLAY_MODE8BIT;
udelay(50);
*LCD_INSTR_ADDR = LCD_DISPLAY_ON;
udelay(50);
*LCD_INSTR_ADDR = LCD_CLEAR;
mdelay(10);
lcd_disp_at_pos("XTENSA LINUX", 0);
return 0;
}
void lcd_disp_at_pos(char *str, unsigned char pos)
{
*LCD_INSTR_ADDR = LCD_DISPLAY_POS | pos;
udelay(100);
while (*str != 0) {
*LCD_DATA_ADDR = *str;
udelay(200);
str++;
}
}
void lcd_shiftleft(void)
{
*LCD_INSTR_ADDR = LCD_SHIFT_LEFT;
udelay(50);
}
void lcd_shiftright(void)
{
*LCD_INSTR_ADDR = LCD_SHIFT_RIGHT;
udelay(50);
}
arch_initcall(lcd_init);