42 lines
1.0 KiB
C
42 lines
1.0 KiB
C
/* early printk support
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*
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* Copyright (c) 2009 Philippe Vachon <philippe@cowpig.ca>
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* Copyright (c) 2009 Lemote Inc.
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* Author: Wu Zhangjin, wuzhangjin@gmail.com
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#include <linux/serial_reg.h>
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#include <loongson.h>
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#define PORT(base, offset) (u8 *)(base + offset)
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static inline unsigned int serial_in(unsigned char *base, int offset)
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{
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return readb(PORT(base, offset));
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}
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static inline void serial_out(unsigned char *base, int offset, int value)
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{
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writeb(value, PORT(base, offset));
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}
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void prom_putchar(char c)
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{
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int timeout;
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unsigned char *uart_base;
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uart_base = (unsigned char *)_loongson_uart_base;
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timeout = 1024;
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while (((serial_in(uart_base, UART_LSR) & UART_LSR_THRE) == 0) &&
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(timeout-- > 0))
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;
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serial_out(uart_base, UART_TX, c);
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}
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