ixp425_wdog.c revision 308325 
1/*-
2 * Copyright (c) 2006 Sam Leffler.  All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 */
24#include <sys/cdefs.h>
25__FBSDID("$FreeBSD: stable/11/sys/arm/xscale/ixp425/ixp425_wdog.c 308325 2016-11-05 04:30:44Z mmel $");
26
27/*
28 * IXP4XX Watchdog Timer Support.
29 */
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/kernel.h>
33#include <sys/module.h>
34#include <sys/time.h>
35#include <sys/bus.h>
36#include <sys/resource.h>
37#include <sys/rman.h>
38#include <sys/watchdog.h>
39
40#include <machine/bus.h>
41#include <machine/resource.h>
42#include <machine/intr.h>
43
44#include <arm/xscale/ixp425/ixp425reg.h>
45#include <arm/xscale/ixp425/ixp425var.h>
46
47struct ixpwdog_softc {
48	device_t		sc_dev;
49};
50
51static __inline uint32_t
52RD4(struct ixpwdog_softc *sc, bus_size_t off)
53{
54	return bus_space_read_4(&ixp425_bs_tag, IXP425_TIMER_VBASE, off);
55}
56
57static __inline void
58WR4(struct ixpwdog_softc *sc, bus_size_t off, uint32_t val)
59{
60	bus_space_write_4(&ixp425_bs_tag, IXP425_TIMER_VBASE, off, val);
61}
62
63static void
64ixp425_watchdog(void *arg, u_int cmd, int *error)
65{
66	struct ixpwdog_softc *sc = arg;
67	u_int u = cmd & WD_INTERVAL;
68
69	WR4(sc, IXP425_OST_WDOG_KEY, OST_WDOG_KEY_MAJICK);
70	if (4 <= u && u <= 35) {
71		WR4(sc, IXP425_OST_WDOG_ENAB, 0);
72		/* approximate 66.66MHz cycles */
73		WR4(sc, IXP425_OST_WDOG, 2<<(u - 4));
74		/* NB: reset on timer expiration */
75		WR4(sc, IXP425_OST_WDOG_ENAB,
76		    OST_WDOG_ENAB_CNT_ENA | OST_WDOG_ENAB_RST_ENA);
77		*error = 0;
78	} else {
79		/* disable watchdog */
80		WR4(sc, IXP425_OST_WDOG_ENAB, 0);
81	}
82	WR4(sc, IXP425_OST_WDOG_KEY, 0);
83}
84
85static int
86ixpwdog_probe(device_t dev)
87{
88	device_set_desc(dev, "IXP4XX Watchdog Timer");
89	return (0);
90}
91
92static int
93ixpwdog_attach(device_t dev)
94{
95	struct ixpwdog_softc *sc = device_get_softc(dev);
96
97	sc->sc_dev = dev;
98
99	EVENTHANDLER_REGISTER(watchdog_list, ixp425_watchdog, sc, 0);
100	return (0);
101}
102
103static device_method_t ixpwdog_methods[] = {
104	DEVMETHOD(device_probe,		ixpwdog_probe),
105	DEVMETHOD(device_attach,	ixpwdog_attach),
106	{0, 0},
107};
108
109static driver_t ixpwdog_driver = {
110	"ixpwdog",
111	ixpwdog_methods,
112	sizeof(struct ixpwdog_softc),
113};
114static devclass_t ixpwdog_devclass;
115DRIVER_MODULE(ixpwdog, ixp, ixpwdog_driver, ixpwdog_devclass, 0, 0);
116