summaryrefslogtreecommitdiff
path: root/arch/powerpc/kernel/udbg.c
blob: 9567d9474c80911a132be02c1e98720238bb88e4 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
/*
 * polling mode stateless debugging stuff, originally for NS16550 Serial Ports
 *
 * c 2001 PPC 64 Team, IBM Corp
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#include <stdarg.h>
#include <linux/config.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/console.h>
#include <asm/processor.h>

void (*udbg_putc)(char c);
int (*udbg_getc)(void);
int (*udbg_getc_poll)(void);

/* udbg library, used by xmon et al */
void udbg_puts(const char *s)
{
	if (udbg_putc) {
		char c;

		if (s && *s != '\0') {
			while ((c = *s++) != '\0')
				udbg_putc(c);
		}
	}
#if 0
	else {
		printk("%s", s);
	}
#endif
}

int udbg_write(const char *s, int n)
{
	int remain = n;
	char c;

	if (!udbg_putc)
		return 0;

	if (s && *s != '\0') {
		while (((c = *s++) != '\0') && (remain-- > 0)) {
			udbg_putc(c);
		}
	}

	return n - remain;
}

int udbg_read(char *buf, int buflen)
{
	char *p = buf;
	int i, c;

	if (!udbg_getc)
		return 0;

	for (i = 0; i < buflen; ++i) {
		do {
			c = udbg_getc();
			if (c == -1 && i == 0)
				return -1;

		} while (c == 0x11 || c == 0x13);
		if (c == 0 || c == -1)
			break;
		*p++ = c;
	}

	return i;
}

#define UDBG_BUFSIZE 256
void udbg_printf(const char *fmt, ...)
{
	char buf[UDBG_BUFSIZE];
	va_list args;

	va_start(args, fmt);
	vsnprintf(buf, UDBG_BUFSIZE, fmt, args);
	udbg_puts(buf);
	va_end(args);
}

/*
 * Early boot console based on udbg
 */
static void udbg_console_write(struct console *con, const char *s,
		unsigned int n)
{
	udbg_write(s, n);
}

static struct console udbg_console = {
	.name	= "udbg",
	.write	= udbg_console_write,
	.flags	= CON_PRINTBUFFER | CON_ENABLED,
	.index	= -1,
};

static int early_console_initialized;

void __init disable_early_printk(void)
{
#if 1
	if (!early_console_initialized)
		return;
	unregister_console(&udbg_console);
	early_console_initialized = 0;
#endif
}

/* called by setup_system */
void register_early_udbg_console(void)
{
	if (early_console_initialized)
		return;
	early_console_initialized = 1;
	register_console(&udbg_console);
}

#if 0   /* if you want to use this as a regular output console */
console_initcall(register_udbg_console);
#endif