1/*
2 * Beat hypervisor console driver
3 *
4 * (C) Copyright 2006 TOSHIBA CORPORATION
5 *
6 * This code is based on drivers/char/hvc_rtas.c:
7 * (C) Copyright IBM Corporation 2001-2005
8 * (C) Copyright Red Hat, Inc. 2005
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License along
21 * with this program; if not, write to the Free Software Foundation, Inc.,
22 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
23 */
24
25#include <linux/module.h>
26#include <linux/init.h>
27#include <linux/err.h>
28#include <linux/string.h>
29#include <linux/console.h>
30#include <asm/prom.h>
31#include <asm/hvconsole.h>
32#include <asm/firmware.h>
33
34#include "hvc_console.h"
35
36extern int64_t beat_get_term_char(uint64_t, uint64_t *, uint64_t *, uint64_t *);
37extern int64_t beat_put_term_char(uint64_t, uint64_t, uint64_t, uint64_t);
38
39struct hvc_struct *hvc_beat_dev = NULL;
40
41/* bug: only one queue is available regardless of vtermno */
42static int hvc_beat_get_chars(uint32_t vtermno, char *buf, int cnt)
43{
44	static unsigned char q[sizeof(unsigned long) * 2]
45		__attribute__((aligned(sizeof(unsigned long))));
46	static int qlen = 0;
47	u64 got;
48
49again:
50	if (qlen) {
51		if (qlen > cnt) {
52			memcpy(buf, q, cnt);
53			qlen -= cnt;
54			memmove(q + cnt, q, qlen);
55			return cnt;
56		} else {	/* qlen <= cnt */
57			int	r;
58
59			memcpy(buf, q, qlen);
60			r = qlen;
61			qlen = 0;
62			return r;
63		}
64	}
65	if (beat_get_term_char(vtermno, &got,
66		((u64 *)q), ((u64 *)q) + 1) == 0) {
67		qlen = got;
68		goto again;
69	}
70	return 0;
71}
72
73static int hvc_beat_put_chars(uint32_t vtermno, const char *buf, int cnt)
74{
75	unsigned long kb[2];
76	int rest, nlen;
77
78	for (rest = cnt; rest > 0; rest -= nlen) {
79		nlen = (rest > 16) ? 16 : rest;
80		memcpy(kb, buf, nlen);
81		beat_put_term_char(vtermno, nlen, kb[0], kb[1]);
82		buf += nlen;
83	}
84	return cnt;
85}
86
87static const struct hv_ops hvc_beat_get_put_ops = {
88	.get_chars = hvc_beat_get_chars,
89	.put_chars = hvc_beat_put_chars,
90};
91
92static int hvc_beat_useit = 1;
93
94static int hvc_beat_config(char *p)
95{
96	hvc_beat_useit = simple_strtoul(p, NULL, 0);
97	return 0;
98}
99
100static int __init hvc_beat_console_init(void)
101{
102	if (hvc_beat_useit && of_machine_is_compatible("Beat")) {
103		hvc_instantiate(0, 0, &hvc_beat_get_put_ops);
104	}
105	return 0;
106}
107
108/* temp */
109static int __init hvc_beat_init(void)
110{
111	struct hvc_struct *hp;
112
113	if (!firmware_has_feature(FW_FEATURE_BEAT))
114		return -ENODEV;
115
116	hp = hvc_alloc(0, 0, &hvc_beat_get_put_ops, 16);
117	if (IS_ERR(hp))
118		return PTR_ERR(hp);
119	hvc_beat_dev = hp;
120	return 0;
121}
122
123static void __exit hvc_beat_exit(void)
124{
125	if (hvc_beat_dev)
126		hvc_remove(hvc_beat_dev);
127}
128
129module_init(hvc_beat_init);
130module_exit(hvc_beat_exit);
131
132__setup("hvc_beat=", hvc_beat_config);
133
134console_initcall(hvc_beat_console_init);
135