1// SPDX-License-Identifier: GPL-2.0
2/*
3 * console.c: Routines that deal with sending and receiving IO
4 *            to/from the current console device using the PROM.
5 *
6 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
7 * Copyright (C) 1998 Pete Zaitcev <zaitcev@yahoo.com>
8 */
9
10#include <linux/types.h>
11#include <linux/kernel.h>
12#include <linux/sched.h>
13#include <asm/openprom.h>
14#include <asm/oplib.h>
15#include <linux/string.h>
16
17extern void restore_current(void);
18
19/* Non blocking put character to console device, returns -1 if
20 * unsuccessful.
21 */
22static int prom_nbputchar(const char *buf)
23{
24	unsigned long flags;
25	int i = -1;
26
27	spin_lock_irqsave(&prom_lock, flags);
28	switch(prom_vers) {
29	case PROM_V0:
30		if ((*(romvec->pv_nbputchar))(*buf))
31			i = 1;
32		break;
33	case PROM_V2:
34	case PROM_V3:
35		if ((*(romvec->pv_v2devops).v2_dev_write)(*romvec->pv_v2bootargs.fd_stdout,
36							  buf, 0x1) == 1)
37			i = 1;
38		break;
39	default:
40		break;
41	}
42	restore_current();
43	spin_unlock_irqrestore(&prom_lock, flags);
44	return i; /* Ugh, we could spin forever on unsupported proms ;( */
45}
46
47void prom_console_write_buf(const char *buf, int len)
48{
49	while (len) {
50		int n = prom_nbputchar(buf);
51		if (n < 0)
52			continue;
53		len--;
54		buf++;
55	}
56}
57
58