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 char * buf,int count)22 static 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
hvc_udbg_get(uint32_t vtermno,char * buf,int count)32 static 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
48 static const struct hv_ops hvc_udbg_ops = {
49 .get_chars = hvc_udbg_get,
50 .put_chars = hvc_udbg_put,
51 };
52
hvc_udbg_init(void)53 static 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 }
70 device_initcall(hvc_udbg_init);
71
hvc_udbg_console_init(void)72 static 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 }
82 console_initcall(hvc_udbg_console_init);
83