satip-axe/kernel/arch/mips/loongson/common/early_printk.c

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/* 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/serial_reg.h>
#include <loongson.h>
#include <machine.h>
#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(LOONGSON_UART_BASE, 8);
while ((serial_in(uart_base, UART_LSR) & UART_LSR_THRE) == 0)
;
serial_out(uart_base, UART_TX, c);
}