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

   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#include <asm/mips-boards/prom.h>
  12
  13static unsigned int display_count;
  14static unsigned int max_display_count;
  15
  16#define LCD_DISPLAY_POS_BASE            0x1f000400
  17#define DISPLAY_LCDINSTRUCTION          (0*2)
  18#define DISPLAY_LCDDATA                 (1*2)
  19#define DISPLAY_CPLDSTATUS              (2*2)
  20#define DISPLAY_CPLDDATA                (3*2)
  21#define LCD_SETDDRAM                    0x80
  22#define LCD_IR_BF                       0x80
  23
  24const char display_string[] = "               LINUX ON SEAD3               ";
  25
  26static void scroll_display_message(unsigned long data);
  27static DEFINE_TIMER(mips_scroll_timer, scroll_display_message, HZ, 0);
  28
  29static void lcd_wait(unsigned int __iomem *display)
  30{
  31        /* Wait for CPLD state machine to become idle. */
  32        do { } while (__raw_readl(display + DISPLAY_CPLDSTATUS) & 1);
  33
  34        do {
  35                __raw_readl(display + DISPLAY_LCDINSTRUCTION);
  36
  37                /* Wait for CPLD state machine to become idle. */
  38                do { } while (__raw_readl(display + DISPLAY_CPLDSTATUS) & 1);
  39        } while (__raw_readl(display + DISPLAY_CPLDDATA) & LCD_IR_BF);
  40}
  41
  42void mips_display_message(const char *str)
  43{
  44        static unsigned int __iomem *display;
  45        char ch;
  46        int i;
  47
  48        if (unlikely(display == NULL))
  49                display = ioremap_nocache(LCD_DISPLAY_POS_BASE,
  50                        (8 * sizeof(int)));
  51
  52        for (i = 0; i < 16; i++) {
  53                if (*str)
  54                        ch = *str++;
  55                else
  56                        ch = ' ';
  57                lcd_wait(display);
  58                __raw_writel((LCD_SETDDRAM | i),
  59                        (display + DISPLAY_LCDINSTRUCTION));
  60                lcd_wait(display);
  61                __raw_writel(ch, display + DISPLAY_LCDDATA);
  62        }
  63}
  64
  65static void scroll_display_message(unsigned long data)
  66{
  67        mips_display_message(&display_string[display_count++]);
  68        if (display_count == max_display_count)
  69                display_count = 0;
  70        mod_timer(&mips_scroll_timer, jiffies + HZ);
  71}
  72
  73void mips_scroll_message(void)
  74{
  75        del_timer_sync(&mips_scroll_timer);
  76        max_display_count = strlen(display_string) + 1 - 16;
  77        mod_timer(&mips_scroll_timer, jiffies + 1);
  78}
  79