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
20 static struct hvc_struct *hvc_udbg_dev;
21
hvc_udbg_put(uint32_t vtermno,const u8 * buf,size_t count)22 static ssize_t hvc_udbg_put(uint32_t vtermno, const u8 *buf, size_t count)
23 {
24 size_t i;
25
26 for (i = 0; i < count && udbg_putc; i++)
27 udbg_putc(buf[i]);
28
29 return i;
30 }
31
hvc_udbg_get(uint32_t vtermno,u8 * buf,size_t count)32 static ssize_t hvc_udbg_get(uint32_t vtermno, u8 *buf, size_t count)
33 {
34 size_t i;
35 int c;
36
37 if (!udbg_getc_poll)
38 return 0;
39
40 for (i = 0; i < count; i++) {
41 if ((c = udbg_getc_poll()) == -1)
42 break;
43 buf[i] = c;
44 }
45
46 return i;
47 }
48
49 static const struct hv_ops hvc_udbg_ops = {
50 .get_chars = hvc_udbg_get,
51 .put_chars = hvc_udbg_put,
52 };
53
hvc_udbg_init(void)54 static int __init hvc_udbg_init(void)
55 {
56 struct hvc_struct *hp;
57
58 if (!udbg_putc)
59 return -ENODEV;
60
61 BUG_ON(hvc_udbg_dev);
62
63 hp = hvc_alloc(0, 0, &hvc_udbg_ops, 16);
64 if (IS_ERR(hp))
65 return PTR_ERR(hp);
66
67 hvc_udbg_dev = hp;
68
69 return 0;
70 }
71 device_initcall(hvc_udbg_init);
72
hvc_udbg_console_init(void)73 static int __init hvc_udbg_console_init(void)
74 {
75 if (!udbg_putc)
76 return -ENODEV;
77
78 hvc_instantiate(0, 0, &hvc_udbg_ops);
79 add_preferred_console("hvc", 0, NULL);
80
81 return 0;
82 }
83 console_initcall(hvc_udbg_console_init);
84