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