1/*-
2 * Copyright (c) 2012 Alexander Rybalko <ray@freebsd.org>
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#include <sys/cdefs.h>
27__FBSDID("$FreeBSD$");
28
29#include <sys/param.h>
30#include <sys/systm.h>
31#include <sys/watchdog.h>
32#include <sys/bus.h>
33#include <sys/kernel.h>
34#include <sys/module.h>
35#include <sys/rman.h>
36
37#include <dev/fdt/fdt_common.h>
38#include <dev/ofw/openfirm.h>
39#include <dev/ofw/ofw_bus.h>
40#include <dev/ofw/ofw_bus_subr.h>
41
42#include <machine/bus.h>
43#include <machine/cpufunc.h>
44#include <machine/machdep.h>
45#include <machine/fdt.h>
46
47#include <arm/broadcom/bcm2835/bcm2835_wdog.h>
48
49#define	BCM2835_PASWORD		0x5a
50
51#define BCM2835_WDOG_RESET	0
52#define BCM2835_PASSWORD_MASK	0xff000000
53#define BCM2835_PASSWORD_SHIFT	24
54#define BCM2835_WDOG_TIME_MASK	0x000fffff
55#define BCM2835_WDOG_TIME_SHIFT	0
56
57#define	READ(_sc, _r) bus_space_read_4((_sc)->bst, (_sc)->bsh, (_r))
58#define	WRITE(_sc, _r, _v) bus_space_write_4((_sc)->bst, (_sc)->bsh, (_r), (_v))
59
60#define BCM2835_RSTC_WRCFG_CLR		0xffffffcf
61#define BCM2835_RSTC_WRCFG_SET		0x00000030
62#define BCM2835_RSTC_WRCFG_FULL_RESET	0x00000020
63#define BCM2835_RSTC_RESET		0x00000102
64
65#define	BCM2835_RSTC_REG	0x00
66#define	BCM2835_RSTS_REG	0x04
67#define	BCM2835_WDOG_REG	0x08
68
69static struct bcmwd_softc *bcmwd_lsc = NULL;
70
71struct bcmwd_softc {
72	device_t		dev;
73	struct resource *	res;
74	bus_space_tag_t		bst;
75	bus_space_handle_t	bsh;
76	int			wdog_armed;
77	int			wdog_period;
78	char			wdog_passwd;
79};
80
81#ifdef notyet
82static void bcmwd_watchdog_fn(void *private, u_int cmd, int *error);
83#endif
84
85static int
86bcmwd_probe(device_t dev)
87{
88
89	if (ofw_bus_is_compatible(dev, "broadcom,bcm2835-wdt")) {
90		device_set_desc(dev, "BCM2708/2835 Watchdog");
91		return (BUS_PROBE_DEFAULT);
92	}
93
94	return (ENXIO);
95}
96
97static int
98bcmwd_attach(device_t dev)
99{
100	struct bcmwd_softc *sc;
101	int rid;
102
103	if (bcmwd_lsc != NULL)
104		return (ENXIO);
105
106	sc = device_get_softc(dev);
107	sc->wdog_period = 7;
108	sc->wdog_passwd = BCM2835_PASWORD;
109	sc->wdog_armed = 0;
110	sc->dev = dev;
111
112	rid = 0;
113	sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
114	if (sc->res == NULL) {
115		device_printf(dev, "could not allocate memory resource\n");
116		return (ENXIO);
117	}
118
119	sc->bst = rman_get_bustag(sc->res);
120	sc->bsh = rman_get_bushandle(sc->res);
121
122	bcmwd_lsc = sc;
123#ifdef notyet
124	EVENTHANDLER_REGISTER(watchdog_list, bcmwd_watchdog_fn, sc, 0);
125#endif
126	return (0);
127}
128
129#ifdef notyet
130static void
131bcmwd_watchdog_fn(void *private, u_int cmd, int *error)
132{
133	/* XXX: not yet */
134}
135#endif
136
137void
138bcmwd_watchdog_reset()
139{
140
141	if (bcmwd_lsc == NULL)
142		return;
143
144	WRITE(bcmwd_lsc, BCM2835_WDOG_REG,
145	    (BCM2835_PASWORD << BCM2835_PASSWORD_SHIFT) | 10);
146
147	WRITE(bcmwd_lsc, BCM2835_RSTC_REG,
148	    (READ(bcmwd_lsc, BCM2835_RSTC_REG) & BCM2835_RSTC_WRCFG_CLR) |
149		(BCM2835_PASWORD << BCM2835_PASSWORD_SHIFT) |
150		BCM2835_RSTC_WRCFG_FULL_RESET);
151}
152
153static device_method_t bcmwd_methods[] = {
154	DEVMETHOD(device_probe, bcmwd_probe),
155	DEVMETHOD(device_attach, bcmwd_attach),
156
157	DEVMETHOD_END
158};
159
160static driver_t bcmwd_driver = {
161	"bcmwd",
162	bcmwd_methods,
163	sizeof(struct bcmwd_softc),
164};
165static devclass_t bcmwd_devclass;
166
167DRIVER_MODULE(bcmwd, simplebus, bcmwd_driver, bcmwd_devclass, 0, 0);
168