arch/mips/dec/prom/console.c

   1 /*
   2  *      arch/mips/dec/prom/console.c
   3  *
   4  *      DECstation PROM-based early console support.
   5  *
   6  *      Copyright (C) 2004  Maciej W. Rozycki
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13 #include <linux/console.h>
  14 #include <linux/init.h>
  15 #include <linux/kernel.h>
  16
  17 #include <asm/dec/prom.h>
  18
  19 static void __init prom_console_write(struct console *con, const char *s,
  20                                       unsigned int c)
  21 {
  22         static char sfmt[] __initdata = "%%%us";
  23         char fmt[13];
  24
  25         snprintf(fmt, sizeof(fmt), sfmt, c);
  26         prom_printf(fmt, s);
  27 }
  28
  29 static struct console promcons __initdata = {
  30         .name   = "prom",
  31         .write  = prom_console_write,
  32         .flags  = CON_PRINTBUFFER,
  33         .index  = -1,
  34 };
  35
  36 static int promcons_output __initdata = 0;
  37
  38 void __init register_prom_console(void)
  39 {
  40         if (!promcons_output) {
  41                 promcons_output = 1;
  42                 register_console(&promcons);
  43         }
  44 }
  45
  46 void __init unregister_prom_console(void)
  47 {
  48         if (promcons_output) {
  49                 unregister_console(&promcons);
  50                 promcons_output = 0;
  51         }
  52 }
  53
  54 void disable_early_printk(void)
  55         __attribute__((alias("unregister_prom_console")));