linux/arch/mips/mti-sead3/sead3-display.c

78 lines
2.0 KiB
C

/*
* 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) 2012 MIPS Technologies, Inc. All rights reserved.
*/
#include <linux/timer.h>
#include <linux/io.h>
#include <asm/mips-boards/generic.h>
static unsigned int display_count;
static unsigned int max_display_count;
#define LCD_DISPLAY_POS_BASE 0x1f000400
#define DISPLAY_LCDINSTRUCTION (0*2)
#define DISPLAY_LCDDATA (1*2)
#define DISPLAY_CPLDSTATUS (2*2)
#define DISPLAY_CPLDDATA (3*2)
#define LCD_SETDDRAM 0x80
#define LCD_IR_BF 0x80
const char display_string[] = " LINUX ON SEAD3 ";
static void scroll_display_message(unsigned long data);
static DEFINE_TIMER(mips_scroll_timer, scroll_display_message, HZ, 0);
static void lcd_wait(unsigned int __iomem *display)
{
/* Wait for CPLD state machine to become idle. */
do { } while (__raw_readl(display + DISPLAY_CPLDSTATUS) & 1);
do {
__raw_readl(display + DISPLAY_LCDINSTRUCTION);
/* Wait for CPLD state machine to become idle. */
do { } while (__raw_readl(display + DISPLAY_CPLDSTATUS) & 1);
} while (__raw_readl(display + DISPLAY_CPLDDATA) & LCD_IR_BF);
}
void mips_display_message(const char *str)
{
static unsigned int __iomem *display;
char ch;
int i;
if (unlikely(display == NULL))
display = ioremap_nocache(LCD_DISPLAY_POS_BASE,
(8 * sizeof(int)));
for (i = 0; i < 16; i++) {
if (*str)
ch = *str++;
else
ch = ' ';
lcd_wait(display);
__raw_writel((LCD_SETDDRAM | i),
(display + DISPLAY_LCDINSTRUCTION));
lcd_wait(display);
__raw_writel(ch, display + DISPLAY_LCDDATA);
}
}
static void scroll_display_message(unsigned long data)
{
mips_display_message(&display_string[display_count++]);
if (display_count == max_display_count)
display_count = 0;
mod_timer(&mips_scroll_timer, jiffies + HZ);
}
void mips_scroll_message(void)
{
del_timer_sync(&mips_scroll_timer);
max_display_count = strlen(display_string) + 1 - 16;
mod_timer(&mips_scroll_timer, jiffies + 1);
}