arch/mips/mti-malta/malta-console.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  * Putting things on the screen/serial line using YAMONs facilities.
  19  */
  20 #include <linux/console.h>
  21 #include <linux/init.h>
  22 #include <linux/serial_reg.h>
  23 #include <asm/io.h>
  24
  25
  26 #define PORT(offset) (0x3f8 + (offset))
  27
  28
  29 static inline unsigned int serial_in(int offset)
  30 {
  31         return inb(PORT(offset));
  32 }
  33
  34 static inline void serial_out(int offset, int value)
  35 {
  36         outb(value, PORT(offset));
  37 }
  38
  39 int prom_putchar(char c)
  40 {
  41         while ((serial_in(UART_LSR) & UART_LSR_THRE) == 0)
  42                 ;
  43
  44         serial_out(UART_TX, c);
  45
  46         return 1;
  47 }