early_printk.c

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 *
 4 *  Copyright (C) 2010 John Crispin <john@phrozen.org>
 5 */
 6
 7#include <linux/cpu.h>
 8#include <lantiq_soc.h>
 9#include <asm/setup.h>
10
11#define ASC_BUF		1024
12#define LTQ_ASC_FSTAT	((u32 *)(LTQ_EARLY_ASC + 0x0048))
13#ifdef __BIG_ENDIAN
14#define LTQ_ASC_TBUF	((u32 *)(LTQ_EARLY_ASC + 0x0020 + 3))
15#else
16#define LTQ_ASC_TBUF	((u32 *)(LTQ_EARLY_ASC + 0x0020))
17#endif
18#define TXMASK		0x3F00
19#define TXOFFSET	8
20
21void prom_putchar(char c)
22{
23	unsigned long flags;
24
25	local_irq_save(flags);
26	do { } while ((ltq_r32(LTQ_ASC_FSTAT) & TXMASK) >> TXOFFSET);
27	if (c == '\n')
28		ltq_w8('\r', LTQ_ASC_TBUF);
29	ltq_w8(c, LTQ_ASC_TBUF);
30	local_irq_restore(flags);
31}