xref: /openbmc/linux/arch/mips/fw/arc/promlib.c (revision 9cfc5c90)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1996 David S. Miller (dm@sgi.com)
7  * Compatibility with board caches, Ulf Carlsson
8  */
9 #include <linux/kernel.h>
10 #include <asm/sgialib.h>
11 #include <asm/bcache.h>
12 
13 /*
14  * IP22 boardcache is not compatible with board caches.	 Thus we disable it
15  * during romvec action.  Since r4xx0.c is always compiled and linked with your
16  * kernel, this shouldn't cause any harm regardless what MIPS processor you
17  * have.
18  *
19  * The ARC write and read functions seem to interfere with the serial lines
20  * in some way. You should be careful with them.
21  */
22 
23 void prom_putchar(char c)
24 {
25 	ULONG cnt;
26 	CHAR it = c;
27 
28 	bc_disable();
29 	ArcWrite(1, &it, 1, &cnt);
30 	bc_enable();
31 }
32 
33 char prom_getchar(void)
34 {
35 	ULONG cnt;
36 	CHAR c;
37 
38 	bc_disable();
39 	ArcRead(0, &c, 1, &cnt);
40 	bc_enable();
41 
42 	return c;
43 }
44