Warning: That file was not part of the compilation database. It may have many parsing errors.

1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2010, 2014 The Linux Foundation. All rights reserved. */
3
4#include <linux/init.h>
5
6#include <asm/dcc.h>
7#include <asm/processor.h>
8
9#include "hvc_console.h"
10
11/* DCC Status Bits */
12#define DCC_STATUS_RX (1 << 30)
13#define DCC_STATUS_TX (1 << 29)
14
15static int hvc_dcc_put_chars(uint32_t vt, const char *buf, int count)
16{
17 int i;
18
19 for (i = 0; i < count; i++) {
20 while (__dcc_getstatus() & DCC_STATUS_TX)
21 cpu_relax();
22
23 __dcc_putchar(buf[i]);
24 }
25
26 return count;
27}
28
29static int hvc_dcc_get_chars(uint32_t vt, char *buf, int count)
30{
31 int i;
32
33 for (i = 0; i < count; ++i)
34 if (__dcc_getstatus() & DCC_STATUS_RX)
35 buf[i] = __dcc_getchar();
36 else
37 break;
38
39 return i;
40}
41
42static bool hvc_dcc_check(void)
43{
44 unsigned long time = jiffies + (HZ / 10);
45
46 /* Write a test character to check if it is handled */
47 __dcc_putchar('\n');
48
49 while (time_is_after_jiffies(time)) {
50 if (!(__dcc_getstatus() & DCC_STATUS_TX))
51 return true;
52 }
53
54 return false;
55}
56
57static const struct hv_ops hvc_dcc_get_put_ops = {
58 .get_chars = hvc_dcc_get_chars,
59 .put_chars = hvc_dcc_put_chars,
60};
61
62static int __init hvc_dcc_console_init(void)
63{
64 int ret;
65
66 if (!hvc_dcc_check())
67 return -ENODEV;
68
69 /* Returns -1 if error */
70 ret = hvc_instantiate(0, 0, &hvc_dcc_get_put_ops);
71
72 return ret < 0 ? -ENODEV : 0;
73}
74console_initcall(hvc_dcc_console_init);
75
76static int __init hvc_dcc_init(void)
77{
78 struct hvc_struct *p;
79
80 if (!hvc_dcc_check())
81 return -ENODEV;
82
83 p = hvc_alloc(0, 0, &hvc_dcc_get_put_ops, 128);
84
85 return PTR_ERR_OR_ZERO(p);
86}
87device_initcall(hvc_dcc_init);
88

Warning: That file was not part of the compilation database. It may have many parsing errors.