xref: /openbmc/linux/arch/mips/dec/prom/console.c (revision 1da177e4)
1 /*
2  *	arch/mips/dec/prom/console.c
3  *
4  *	DECstation PROM-based early console support.
5  *
6  *	Copyright (C) 2004  Maciej W. Rozycki
7  *
8  *	This program is free software; you can redistribute it and/or
9  *	modify it under the terms of the GNU General Public License
10  *	as published by the Free Software Foundation; either version
11  *	2 of the License, or (at your option) any later version.
12  */
13 #include <linux/console.h>
14 #include <linux/init.h>
15 #include <linux/kernel.h>
16 
17 #include <asm/dec/prom.h>
18 
19 static void __init prom_console_write(struct console *con, const char *s,
20 				      unsigned int c)
21 {
22 	static char sfmt[] __initdata = "%%%us";
23 	char fmt[13];
24 
25 	snprintf(fmt, sizeof(fmt), sfmt, c);
26 	prom_printf(fmt, s);
27 }
28 
29 static struct console promcons __initdata = {
30 	.name	= "prom",
31 	.write	= prom_console_write,
32 	.flags	= CON_PRINTBUFFER,
33 	.index	= -1,
34 };
35 
36 static int promcons_output __initdata = 0;
37 
38 void __init register_prom_console(void)
39 {
40 	if (!promcons_output) {
41 		promcons_output = 1;
42 		register_console(&promcons);
43 	}
44 }
45 
46 void __init unregister_prom_console(void)
47 {
48 	if (promcons_output) {
49 		unregister_console(&promcons);
50 		promcons_output = 0;
51 	}
52 }
53 
54 void disable_early_printk(void)
55 	__attribute__((alias("unregister_prom_console")));
56