MIPS: Loongson: Add new early_printk implmentation

obj-y += setup.o prom.o reset.o irq.o pci.o bonito-irq.o mem.o

#

# Early printk support

#

obj-$(CONFIG_EARLY_PRINTK) += early_printk.o

EXTRA_CFLAGS += -Werror

/*  early printk support

 *

 *  Copyright (c) 2009 Philippe Vachon <philippe@cowpig.ca>

 *  Copyright (C) 2009 Lemote Inc. & Insititute of Computing Technology

 *  Author: Wu Zhangjin, wuzj@lemote.com

 *

 *  This program is free software; you can redistribute  it and/or modify it

 *  under  the terms of  the GNU General  Public License as published by the

 *  Free Software Foundation;  either version 2 of the  License, or (at your

 *  option) any later version.

 */

#include <linux/io.h>

#include <linux/init.h>

#include <linux/serial_reg.h>

#include <asm/mips-boards/bonito64.h>

#define UART_BASE (BONITO_PCIIO_BASE + 0x3f8)

#define PORT(base, offset) (u8 *)(base + offset)

static inline unsigned int serial_in(phys_addr_t base, int offset)

{

	return readb(PORT(base, offset));

}

static inline void serial_out(phys_addr_t base, int offset, int value)

{

	writeb(value, PORT(base, offset));

}

void prom_putchar(char c)

{

	phys_addr_t uart_base =

		(phys_addr_t) ioremap_nocache(UART_BASE, 8);

	while ((serial_in(uart_base, UART_LSR) & UART_LSR_THRE) == 0)

		;

	serial_out(uart_base, UART_TX, c);

}