tegrakernel/kernel/kernel-4.9/arch/mips/fw/arc/promlib.c

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2022-02-16 09:13:02 -06:00
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1996 David S. Miller (dm@sgi.com)
* Compatibility with board caches, Ulf Carlsson
*/
#include <linux/kernel.h>
#include <asm/sgialib.h>
#include <asm/bcache.h>
/*
* IP22 boardcache is not compatible with board caches. Thus we disable it
* during romvec action. Since r4xx0.c is always compiled and linked with your
* kernel, this shouldn't cause any harm regardless what MIPS processor you
* have.
*
* The ARC write and read functions seem to interfere with the serial lines
* in some way. You should be careful with them.
*/
void prom_putchar(char c)
{
ULONG cnt;
CHAR it = c;
bc_disable();
ArcWrite(1, &it, 1, &cnt);
bc_enable();
}
char prom_getchar(void)
{
ULONG cnt;
CHAR c;
bc_disable();
ArcRead(0, &c, 1, &cnt);
bc_enable();
return c;
}