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(ptr: hvc_alloc(vtermno: 0, data: 0, ops: &hvc_sbi_dbcn_ops, outbuf_size: 256));
69 if (err)
70 return err;
71 hvc_instantiate(vtermno: 0, index: 0, ops: &hvc_sbi_dbcn_ops);
72 } else if (IS_ENABLED(CONFIG_RISCV_SBI_V01)) {
73 err = PTR_ERR_OR_ZERO(ptr: hvc_alloc(vtermno: 0, data: 0, ops: &hvc_sbi_v01_ops, outbuf_size: 256));
74 if (err)
75 return err;
76 hvc_instantiate(vtermno: 0, index: 0, ops: &hvc_sbi_v01_ops);
77 } else {
78 return -ENODEV;
79 }
80
81 return 0;
82}
83device_initcall(hvc_sbi_init);
84

source code of linux/drivers/tty/hvc/hvc_riscv_sbi.c