xref: /openbmc/linux/drivers/tty/hvc/hvc_udbg.c (revision 4800cd83)
1 /*
2  * udbg interface to hvc_console.c
3  *
4  * (C) Copyright David Gibson, IBM Corporation 2008.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  */
20 
21 #include <linux/console.h>
22 #include <linux/delay.h>
23 #include <linux/err.h>
24 #include <linux/init.h>
25 #include <linux/moduleparam.h>
26 #include <linux/types.h>
27 #include <linux/irq.h>
28 
29 #include <asm/udbg.h>
30 
31 #include "hvc_console.h"
32 
33 struct hvc_struct *hvc_udbg_dev;
34 
35 static int hvc_udbg_put(uint32_t vtermno, const char *buf, int count)
36 {
37 	int i;
38 
39 	for (i = 0; i < count; i++)
40 		udbg_putc(buf[i]);
41 
42 	return i;
43 }
44 
45 static int hvc_udbg_get(uint32_t vtermno, char *buf, int count)
46 {
47 	int i, c;
48 
49 	if (!udbg_getc_poll)
50 		return 0;
51 
52 	for (i = 0; i < count; i++) {
53 		if ((c = udbg_getc_poll()) == -1)
54 			break;
55 		buf[i] = c;
56 	}
57 
58 	return i;
59 }
60 
61 static const struct hv_ops hvc_udbg_ops = {
62 	.get_chars = hvc_udbg_get,
63 	.put_chars = hvc_udbg_put,
64 };
65 
66 static int __init hvc_udbg_init(void)
67 {
68 	struct hvc_struct *hp;
69 
70 	BUG_ON(hvc_udbg_dev);
71 
72 	hp = hvc_alloc(0, NO_IRQ, &hvc_udbg_ops, 16);
73 	if (IS_ERR(hp))
74 		return PTR_ERR(hp);
75 
76 	hvc_udbg_dev = hp;
77 
78 	return 0;
79 }
80 module_init(hvc_udbg_init);
81 
82 static void __exit hvc_udbg_exit(void)
83 {
84 	if (hvc_udbg_dev)
85 		hvc_remove(hvc_udbg_dev);
86 }
87 module_exit(hvc_udbg_exit);
88 
89 static int __init hvc_udbg_console_init(void)
90 {
91 	hvc_instantiate(0, 0, &hvc_udbg_ops);
92 	add_preferred_console("hvc", 0, NULL);
93 
94 	return 0;
95 }
96 console_initcall(hvc_udbg_console_init);
97