Root/drivers/tty/hvc/hvc_udbg.c

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
33struct hvc_struct *hvc_udbg_dev;
34
35static int hvc_udbg_put(uint32_t vtermno, const char *buf, int count)
36{
37    int i;
38
39    for (i = 0; i < count && udbg_putc; i++)
40        udbg_putc(buf[i]);
41
42    return i;
43}
44
45static 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
61static const struct hv_ops hvc_udbg_ops = {
62    .get_chars = hvc_udbg_get,
63    .put_chars = hvc_udbg_put,
64};
65
66static int __init hvc_udbg_init(void)
67{
68    struct hvc_struct *hp;
69
70    if (!udbg_putc)
71        return -ENODEV;
72
73    BUG_ON(hvc_udbg_dev);
74
75    hp = hvc_alloc(0, 0, &hvc_udbg_ops, 16);
76    if (IS_ERR(hp))
77        return PTR_ERR(hp);
78
79    hvc_udbg_dev = hp;
80
81    return 0;
82}
83module_init(hvc_udbg_init);
84
85static void __exit hvc_udbg_exit(void)
86{
87    if (hvc_udbg_dev)
88        hvc_remove(hvc_udbg_dev);
89}
90module_exit(hvc_udbg_exit);
91
92static int __init hvc_udbg_console_init(void)
93{
94    if (!udbg_putc)
95        return -ENODEV;
96
97    hvc_instantiate(0, 0, &hvc_udbg_ops);
98    add_preferred_console("hvc", 0, NULL);
99
100    return 0;
101}
102console_initcall(hvc_udbg_console_init);
103

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