arch/mips/mti-malta/malta-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  * Display routines for display messages in MIPS boards ascii display.
   7  *
   8  * Copyright (C) 1999,2000,2012  MIPS Technologies, Inc.
   9  * All rights reserved.
  10  * Authors: Carsten Langgaard <carstenl@mips.com>
  11  *          Steven J. Hill <sjhill@mips.com>
  12  */
  13 #include <linux/compiler.h>
  14 #include <linux/timer.h>
  15 #include <linux/io.h>
  16
  17 #include <asm/mips-boards/generic.h>
  18
  19 extern const char display_string[];
  20 static unsigned int display_count;
  21 static unsigned int max_display_count;
  22
  23 void mips_display_message(const char *str)
  24 {
  25         static unsigned int __iomem *display = NULL;
  26         int i;
  27
  28         if (unlikely(display == NULL))
  29                 display = ioremap(ASCII_DISPLAY_POS_BASE, 16*sizeof(int));
  30
  31         for (i = 0; i <= 14; i += 2) {
  32                 if (*str)
  33                         __raw_writel(*str++, display + i);
  34                 else
  35                         __raw_writel(' ', display + i);
  36         }
  37 }
  38
  39 static void scroll_display_message(struct timer_list *unused);
  40 static DEFINE_TIMER(mips_scroll_timer, scroll_display_message);
  41
  42 static void scroll_display_message(struct timer_list *unused)
  43 {
  44         mips_display_message(&display_string[display_count++]);
  45         if (display_count == max_display_count)
  46                 display_count = 0;
  47
  48         mod_timer(&mips_scroll_timer, jiffies + HZ);
  49 }
  50
  51 void mips_scroll_message(void)
  52 {
  53         del_timer_sync(&mips_scroll_timer);
  54         max_display_count = strlen(display_string) + 1 - 8;
  55         mod_timer(&mips_scroll_timer, jiffies + 1);
  56 }