1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License.  See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 2012 MIPS Technologies, Inc.  All rights reserved.
7 */
8#include <linux/timer.h>
9#include <linux/io.h>
10#include <asm/mips-boards/generic.h>
11
12static unsigned int display_count;
13static unsigned int max_display_count;
14
15#define LCD_DISPLAY_POS_BASE		0x1f000400
16#define DISPLAY_LCDINSTRUCTION		(0*2)
17#define DISPLAY_LCDDATA			(1*2)
18#define DISPLAY_CPLDSTATUS		(2*2)
19#define DISPLAY_CPLDDATA		(3*2)
20#define LCD_SETDDRAM			0x80
21#define LCD_IR_BF			0x80
22
23const char display_string[] = "		      LINUX ON SEAD3		   ";
24
25static void scroll_display_message(unsigned long data);
26static DEFINE_TIMER(mips_scroll_timer, scroll_display_message, HZ, 0);
27
28static void lcd_wait(unsigned int __iomem *display)
29{
30	/* Wait for CPLD state machine to become idle. */
31	do { } while (__raw_readl(display + DISPLAY_CPLDSTATUS) & 1);
32
33	do {
34		__raw_readl(display + DISPLAY_LCDINSTRUCTION);
35
36		/* Wait for CPLD state machine to become idle. */
37		do { } while (__raw_readl(display + DISPLAY_CPLDSTATUS) & 1);
38	} while (__raw_readl(display + DISPLAY_CPLDDATA) & LCD_IR_BF);
39}
40
41void mips_display_message(const char *str)
42{
43	static unsigned int __iomem *display;
44	char ch;
45	int i;
46
47	if (unlikely(display == NULL))
48		display = ioremap_nocache(LCD_DISPLAY_POS_BASE,
49			(8 * sizeof(int)));
50
51	for (i = 0; i < 16; i++) {
52		if (*str)
53			ch = *str++;
54		else
55			ch = ' ';
56		lcd_wait(display);
57		__raw_writel((LCD_SETDDRAM | i),
58			(display + DISPLAY_LCDINSTRUCTION));
59		lcd_wait(display);
60		__raw_writel(ch, display + DISPLAY_LCDDATA);
61	}
62}
63
64static void scroll_display_message(unsigned long data)
65{
66	mips_display_message(&display_string[display_count++]);
67	if (display_count == max_display_count)
68		display_count = 0;
69	mod_timer(&mips_scroll_timer, jiffies + HZ);
70}
71
72void mips_scroll_message(void)
73{
74	del_timer_sync(&mips_scroll_timer);
75	max_display_count = strlen(display_string) + 1 - 16;
76	mod_timer(&mips_scroll_timer, jiffies + 1);
77}
78