1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 2008 David Gibson, IBM Corporation
4 * Copyright (C) 2012 Regents of the University of California
5 * Copyright (C) 2017 SiFive
6 */
7
8#include <linux/console.h>
9#include <linux/err.h>
10#include <linux/init.h>
11#include <linux/moduleparam.h>
12#include <linux/types.h>
13
14#include <asm/sbi.h>
15
16#include "hvc_console.h"
17
18static ssize_t hvc_sbi_tty_put(uint32_t vtermno, const u8 *buf, size_t count)
19{
20	size_t i;
21
22	for (i = 0; i < count; i++)
23		sbi_console_putchar(buf[i]);
24
25	return i;
26}
27
28static ssize_t hvc_sbi_tty_get(uint32_t vtermno, u8 *buf, size_t count)
29{
30	size_t i;
31	int c;
32
33	for (i = 0; i < count; i++) {
34		c = sbi_console_getchar();
35		if (c < 0)
36			break;
37		buf[i] = c;
38	}
39
40	return i;
41}
42
43static const struct hv_ops hvc_sbi_v01_ops = {
44	.get_chars = hvc_sbi_tty_get,
45	.put_chars = hvc_sbi_tty_put,
46};
47
48static ssize_t hvc_sbi_dbcn_tty_put(uint32_t vtermno, const u8 *buf, size_t count)
49{
50	return sbi_debug_console_write(buf, count);
51}
52
53static ssize_t hvc_sbi_dbcn_tty_get(uint32_t vtermno, u8 *buf, size_t count)
54{
55	return sbi_debug_console_read(buf, count);
56}
57
58static const struct hv_ops hvc_sbi_dbcn_ops = {
59	.put_chars = hvc_sbi_dbcn_tty_put,
60	.get_chars = hvc_sbi_dbcn_tty_get,
61};
62
63static int __init hvc_sbi_init(void)
64{
65	int err;
66
67	if (sbi_debug_console_available) {
68		err = PTR_ERR_OR_ZERO(hvc_alloc(0, 0, &hvc_sbi_dbcn_ops, 256));
69		if (err)
70			return err;
71		hvc_instantiate(0, 0, &hvc_sbi_dbcn_ops);
72	} else if (IS_ENABLED(CONFIG_RISCV_SBI_V01)) {
73		err = PTR_ERR_OR_ZERO(hvc_alloc(0, 0, &hvc_sbi_v01_ops, 256));
74		if (err)
75			return err;
76		hvc_instantiate(0, 0, &hvc_sbi_v01_ops);
77	} else {
78		return -ENODEV;
79	}
80
81	return 0;
82}
83device_initcall(hvc_sbi_init);
84