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v0.7.0
https://github.com/torvalds/linux
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Tip revision: 49a57857aeea06ca831043acbb0fa5e0f50602fd authored by Linus Torvalds on 21 January 2019, 00:14:44 UTC
Linux 5.0-rc3
Tip revision: 49a5785
early_printk.c
/*
 *  This program is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU General Public License version 2 as published
 *  by the Free Software Foundation.
 *
 *  Copyright (C) 2010 John Crispin <john@phrozen.org>
 */

#include <linux/cpu.h>
#include <lantiq_soc.h>
#include <asm/setup.h>

#define ASC_BUF		1024
#define LTQ_ASC_FSTAT	((u32 *)(LTQ_EARLY_ASC + 0x0048))
#ifdef __BIG_ENDIAN
#define LTQ_ASC_TBUF	((u32 *)(LTQ_EARLY_ASC + 0x0020 + 3))
#else
#define LTQ_ASC_TBUF	((u32 *)(LTQ_EARLY_ASC + 0x0020))
#endif
#define TXMASK		0x3F00
#define TXOFFSET	8

void prom_putchar(char c)
{
	unsigned long flags;

	local_irq_save(flags);
	do { } while ((ltq_r32(LTQ_ASC_FSTAT) & TXMASK) >> TXOFFSET);
	if (c == '\n')
		ltq_w8('\r', LTQ_ASC_TBUF);
	ltq_w8(c, LTQ_ASC_TBUF);
	local_irq_restore(flags);
}
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