1/*-
2 * Copyright (c) 2009 Adrian Chadd
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD$
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD$");
31
32#include <sys/param.h>
33#include <sys/systm.h>
34#include <sys/bus.h>
35#include <sys/clock.h>
36#include <sys/lock.h>
37#include <sys/mutex.h>
38#include <sys/kernel.h>
39#include <sys/module.h>
40#include <sys/time.h>
41
42#include <xen/xen_intr.h>
43#include <vm/vm.h>
44#include <vm/pmap.h>
45#include <machine/pmap.h>
46#include <xen/hypervisor.h>
47#include <machine/xen/xen-os.h>
48#include <machine/xen/xenfunc.h>
49#include <xen/interface/io/xenbus.h>
50#include <xen/interface/vcpu.h>
51#include <machine/cpu.h>
52
53#include <machine/xen/xen_clock_util.h>
54
55#include "clock_if.h"
56
57static int
58xen_rtc_probe(device_t dev)
59{
60	device_set_desc(dev, "Xen Hypervisor Clock");
61	printf("[XEN] xen_rtc_probe: probing Hypervisor RTC clock\n");
62	if (! HYPERVISOR_shared_info) {
63		device_printf(dev, "No hypervisor shared page found; RTC can not start.\n");
64		return (EINVAL);
65	}
66	return (0);
67}
68
69static int
70xen_rtc_attach(device_t dev)
71{
72	printf("[XEN] xen_rtc_attach: attaching Hypervisor RTC clock\n");
73	clock_register(dev, 1000000);
74	return(0);
75}
76
77static int
78xen_rtc_settime(device_t dev __unused, struct timespec *ts)
79{
80	device_printf(dev, "[XEN] xen_rtc_settime\n");
81	/*
82	 * Don't return EINVAL here; just silently fail if the domain isn't privileged enough
83	 * to set the TOD.
84	 */
85	return(0);
86}
87
88/*
89 * The Xen time structures document the hypervisor start time and the
90 * uptime-since-hypervisor-start (in nsec.) They need to be combined
91 * in order to calculate a TOD clock.
92 */
93static int
94xen_rtc_gettime(device_t dev, struct timespec *ts)
95{
96	struct timespec w_ts, u_ts;
97
98	device_printf(dev, "[XEN] xen_rtc_gettime\n");
99	xen_fetch_wallclock(&w_ts);
100	device_printf(dev, "[XEN] xen_rtc_gettime: wallclock %ld sec; %ld nsec\n", (long int) w_ts.tv_sec, (long int) w_ts.tv_nsec);
101	xen_fetch_uptime(&u_ts);
102	device_printf(dev, "[XEN] xen_rtc_gettime: uptime %ld sec; %ld nsec\n", (long int) u_ts.tv_sec, (long int) u_ts.tv_nsec);
103
104	timespecclear(ts);
105	timespecadd(ts, &w_ts);
106	timespecadd(ts, &u_ts);
107
108	device_printf(dev, "[XEN] xen_rtc_gettime: TOD %ld sec; %ld nsec\n", (long int) ts->tv_sec, (long int) ts->tv_nsec);
109
110	return(0);
111}
112
113static void
114xen_rtc_identify(driver_t *drv, device_t parent)
115{
116        BUS_ADD_CHILD(parent, 0, "rtc", 0);
117}
118
119static device_method_t xen_rtc_methods[] = {
120	/* Device interface */
121	DEVMETHOD(device_probe,		xen_rtc_probe),
122	DEVMETHOD(device_attach,	xen_rtc_attach),
123	DEVMETHOD(device_identify,	xen_rtc_identify),
124
125	DEVMETHOD(device_detach,	bus_generic_detach),
126	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
127
128	/* clock interface */
129	DEVMETHOD(clock_gettime,	xen_rtc_gettime),
130	DEVMETHOD(clock_settime,	xen_rtc_settime),
131
132	{ 0, 0 }
133};
134
135
136static driver_t xen_rtc_driver = {
137	"rtc",
138	xen_rtc_methods,
139	0
140};
141
142static devclass_t xen_rtc_devclass;
143
144DRIVER_MODULE(rtc, nexus, xen_rtc_driver, xen_rtc_devclass, 0, 0);
145