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f6a2740d WZ |
1 | /* early printk support |
2 | * | |
3 | * Copyright (c) 2009 Philippe Vachon <philippe@cowpig.ca> | |
db54ff24 | 4 | * Copyright (c) 2009 Lemote Inc. |
f6a2740d WZ |
5 | * Author: Wu Zhangjin, wuzj@lemote.com |
6 | * | |
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. | |
11 | */ | |
f6a2740d WZ |
12 | #include <linux/serial_reg.h> |
13 | ||
5e983ff6 | 14 | #include <loongson.h> |
f6a2740d WZ |
15 | |
16 | #define PORT(base, offset) (u8 *)(base + offset) | |
17 | ||
db54ff24 | 18 | static inline unsigned int serial_in(unsigned char *base, int offset) |
f6a2740d WZ |
19 | { |
20 | return readb(PORT(base, offset)); | |
21 | } | |
22 | ||
db54ff24 | 23 | static inline void serial_out(unsigned char *base, int offset, int value) |
f6a2740d WZ |
24 | { |
25 | writeb(value, PORT(base, offset)); | |
26 | } | |
27 | ||
28 | void prom_putchar(char c) | |
29 | { | |
a3ed4951 WZ |
30 | int timeout; |
31 | unsigned char *uart_base; | |
f6a2740d | 32 | |
a3ed4951 WZ |
33 | uart_base = (unsigned char *)_loongson_uart_base; |
34 | timeout = 1024; | |
35 | ||
36 | while (((serial_in(uart_base, UART_LSR) & UART_LSR_THRE) == 0) && | |
37 | (timeout-- > 0)) | |
f6a2740d WZ |
38 | ; |
39 | ||
40 | serial_out(uart_base, UART_TX, c); | |
41 | } |