1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * udbg interface to hvc_console.c
4 *
5 * (C) Copyright David Gibson, IBM Corporation 2008.
6 */
7
8#include <linux/console.h>
9#include <linux/delay.h>
10#include <linux/err.h>
11#include <linux/init.h>
12#include <linux/moduleparam.h>
13#include <linux/types.h>
14#include <linux/irq.h>
15
16#include <asm/udbg.h>
17
18#include "hvc_console.h"
19
20static struct hvc_struct *hvc_udbg_dev;
21
22static int hvc_udbg_put(uint32_t vtermno, const char *buf, int count)
23{
24	int i;
25
26	for (i = 0; i < count && udbg_putc; i++)
27		udbg_putc(buf[i]);
28
29	return i;
30}
31
32static int hvc_udbg_get(uint32_t vtermno, char *buf, int count)
33{
34	int i, c;
35
36	if (!udbg_getc_poll)
37		return 0;
38
39	for (i = 0; i < count; i++) {
40		if ((c = udbg_getc_poll()) == -1)
41			break;
42		buf[i] = c;
43	}
44
45	return i;
46}
47
48static const struct hv_ops hvc_udbg_ops = {
49	.get_chars = hvc_udbg_get,
50	.put_chars = hvc_udbg_put,
51};
52
53static int __init hvc_udbg_init(void)
54{
55	struct hvc_struct *hp;
56
57	if (!udbg_putc)
58		return -ENODEV;
59
60	BUG_ON(hvc_udbg_dev);
61
62	hp = hvc_alloc(0, 0, &hvc_udbg_ops, 16);
63	if (IS_ERR(hp))
64		return PTR_ERR(hp);
65
66	hvc_udbg_dev = hp;
67
68	return 0;
69}
70device_initcall(hvc_udbg_init);
71
72static int __init hvc_udbg_console_init(void)
73{
74	if (!udbg_putc)
75		return -ENODEV;
76
77	hvc_instantiate(0, 0, &hvc_udbg_ops);
78	add_preferred_console("hvc", 0, NULL);
79
80	return 0;
81}
82console_initcall(hvc_udbg_console_init);
83