arch/mips/mips-boards/generic/display.c

   1 /*
   2  * Carsten Langgaard, carstenl@mips.com
   3  * Copyright (C) 1999,2000 MIPS Technologies, Inc.  All rights reserved.
   4  *
   5  *  This program is free software; you can distribute it and/or modify it
   6  *  under the terms of the GNU General Public License (Version 2) as
   7  *  published by the Free Software Foundation.
   8  *
   9  *  This program is distributed in the hope it will be useful, but WITHOUT
  10  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  *  for more details.
  13  *
  14  *  You should have received a copy of the GNU General Public License along
  15  *  with this program; if not, write to the Free Software Foundation, Inc.,
  16  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  17  *
  18  * Display routines for display messages in MIPS boards ascii display.
  19  */
  20
  21 #include <linux/compiler.h>
  22 #include <linux/timer.h>
  23 #include <asm/io.h>
  24 #include <asm/mips-boards/generic.h>
  25
  26 extern const char display_string[];
  27 static unsigned int display_count;
  28 static unsigned int max_display_count;
  29
  30 void mips_display_message(const char *str)
  31 {
  32         static unsigned int __iomem *display = NULL;
  33         int i;
  34
  35         if (unlikely(display == NULL))
  36                 display = ioremap(ASCII_DISPLAY_POS_BASE, 16*sizeof(int));
  37
  38         for (i = 0; i <= 14; i=i+2) {
  39                  if (*str)
  40                          writel(*str++, display + i);
  41                  else
  42                          writel(' ', display + i);
  43         }
  44 }
  45
  46 static void scroll_display_message(unsigned long data);
  47 static DEFINE_TIMER(mips_scroll_timer, scroll_display_message, HZ, 0);
  48
  49 static void scroll_display_message(unsigned long data)
  50 {
  51         mips_display_message(&display_string[display_count++]);
  52         if (display_count == max_display_count)
  53                 display_count = 0;
  54
  55         mod_timer(&mips_scroll_timer, jiffies + HZ);
  56 }
  57
  58 void mips_scroll_message(void)
  59 {
  60         del_timer_sync(&mips_scroll_timer);
  61         max_display_count = strlen(display_string) + 1 - 8;
  62         mod_timer(&mips_scroll_timer, jiffies + 1);
  63 }