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, NO_IRQ, &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);