1 /* early printk support
3 * Copyright (c) 2009 Philippe Vachon <philippe@cowpig.ca>
4 * Copyright (c) 2009 Lemote Inc.
5 * Author: Wu Zhangjin, wuzhangjin@gmail.com
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version.
12 #include <linux/serial_reg.h>
16 #define PORT(base, offset) (u8 *)(base + offset)
18 static inline unsigned int serial_in(unsigned char *base
, int offset
)
20 return readb(PORT(base
, offset
));
23 static inline void serial_out(unsigned char *base
, int offset
, int value
)
25 writeb(value
, PORT(base
, offset
));
28 void prom_putchar(char c
)
31 unsigned char *uart_base
;
33 uart_base
= (unsigned char *)_loongson_uart_base
[0];
36 while (((serial_in(uart_base
, UART_LSR
) & UART_LSR_THRE
) == 0) &&
40 serial_out(uart_base
, UART_TX
, c
);