xref: /OK3568_Linux_fs/kernel/arch/mips/lantiq/early_printk.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  *
4*4882a593Smuzhiyun  *  Copyright (C) 2010 John Crispin <john@phrozen.org>
5*4882a593Smuzhiyun  */
6*4882a593Smuzhiyun 
7*4882a593Smuzhiyun #include <linux/cpu.h>
8*4882a593Smuzhiyun #include <lantiq_soc.h>
9*4882a593Smuzhiyun #include <asm/setup.h>
10*4882a593Smuzhiyun 
11*4882a593Smuzhiyun #define ASC_BUF		1024
12*4882a593Smuzhiyun #define LTQ_ASC_FSTAT	((u32 *)(LTQ_EARLY_ASC + 0x0048))
13*4882a593Smuzhiyun #ifdef __BIG_ENDIAN
14*4882a593Smuzhiyun #define LTQ_ASC_TBUF	((u32 *)(LTQ_EARLY_ASC + 0x0020 + 3))
15*4882a593Smuzhiyun #else
16*4882a593Smuzhiyun #define LTQ_ASC_TBUF	((u32 *)(LTQ_EARLY_ASC + 0x0020))
17*4882a593Smuzhiyun #endif
18*4882a593Smuzhiyun #define TXMASK		0x3F00
19*4882a593Smuzhiyun #define TXOFFSET	8
20*4882a593Smuzhiyun 
prom_putchar(char c)21*4882a593Smuzhiyun void prom_putchar(char c)
22*4882a593Smuzhiyun {
23*4882a593Smuzhiyun 	unsigned long flags;
24*4882a593Smuzhiyun 
25*4882a593Smuzhiyun 	local_irq_save(flags);
26*4882a593Smuzhiyun 	do { } while ((ltq_r32(LTQ_ASC_FSTAT) & TXMASK) >> TXOFFSET);
27*4882a593Smuzhiyun 	if (c == '\n')
28*4882a593Smuzhiyun 		ltq_w8('\r', LTQ_ASC_TBUF);
29*4882a593Smuzhiyun 	ltq_w8(c, LTQ_ASC_TBUF);
30*4882a593Smuzhiyun 	local_irq_restore(flags);
31*4882a593Smuzhiyun }
32