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// SPDX-License-Identifier: GPL-2.0-or-later
/* early printk support
*
* Copyright (c) 2009 Philippe Vachon <philippe@cowpig.ca>
* Copyright (c) 2009 Lemote Inc.
* Author: Wu Zhangjin, wuzhangjin@gmail.com
*/
#include <linux/serial_reg.h>
#include <asm/setup.h>
#include <loongson.h>
#define PORT(base, offset) (u8 *)(base + offset)
static inline unsigned int serial_in(unsigned char *base, int offset)
{
return readb(PORT(base, offset));
}
static inline void serial_out(unsigned char *base, int offset, int value)
{
writeb(value, PORT(base, offset));
}
void prom_putchar(char c)
{
int timeout;
unsigned char *uart_base;
uart_base = (unsigned char *)_loongson_uart_base;
timeout = 1024;
while (((serial_in(uart_base, UART_LSR) & UART_LSR_THRE) == 0) &&
(timeout-- > 0))
;
serial_out(uart_base, UART_TX, c);
}
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