arch/mips/mti-sead3/sead3-console.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/init.h>
   9 #include <linux/console.h>
  10 #include <linux/serial_reg.h>
  11 #include <linux/io.h>
  12
  13 #define SEAD_UART1_REGS_BASE    0xbf000800   /* ttyS1 = DB9 port */
  14 #define SEAD_UART0_REGS_BASE    0xbf000900   /* ttyS0 = USB port   */
  15 #define PORT(base_addr, offset) ((unsigned int __iomem *)(base_addr+(offset)*4))
  16
  17 static char console_port = 1;
  18
  19 static inline unsigned int serial_in(int offset, unsigned int base_addr)
  20 {
  21         return __raw_readl(PORT(base_addr, offset)) & 0xff;
  22 }
  23
  24 static inline void serial_out(int offset, int value, unsigned int base_addr)
  25 {
  26         __raw_writel(value, PORT(base_addr, offset));
  27 }
  28
  29 void __init prom_init_early_console(char port)
  30 {
  31         console_port = port;
  32 }
  33
  34 int prom_putchar(char c)
  35 {
  36         unsigned int base_addr;
  37
  38         base_addr = console_port ? SEAD_UART1_REGS_BASE : SEAD_UART0_REGS_BASE;
  39
  40         while ((serial_in(UART_LSR, base_addr) & UART_LSR_THRE) == 0)
  41                 ;
  42
  43         serial_out(UART_TX, c, base_addr);
  44
  45         return 1;
  46 }