1/*-
2 * Copyright (c) 2013 Oleksandr Tymoshenko <gonzo@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/lock.h>
35#include <sys/module.h>
36#include <sys/mutex.h>
37#include <sys/rman.h>
38
39#include <dev/fdt/fdt_common.h>
40#include <dev/ofw/openfirm.h>
41#include <dev/ofw/ofw_bus.h>
42#include <dev/ofw/ofw_bus_subr.h>
43
44#include <machine/bus.h>
45#include <machine/cpufunc.h>
46#include <machine/machdep.h>
47#include <machine/fdt.h>
48
49#include <arm/allwinner/a10_wdog.h>
50
51#define	READ(_sc, _r) bus_read_4((_sc)->res, (_r))
52#define	WRITE(_sc, _r, _v) bus_write_4((_sc)->res, (_r), (_v))
53
54#define	WDOG_CTRL		0x00
55#define		WDOG_CTRL_RESTART	(1 << 0)
56#define	WDOG_MODE		0x04
57#define		WDOG_MODE_INTVL_SHIFT	3
58#define		WDOG_MODE_RST_EN	(1 << 1)
59#define		WDOG_MODE_EN		(1 << 0)
60
61struct a10wd_interval {
62	uint64_t	milliseconds;
63	unsigned int	value;
64};
65
66struct a10wd_interval wd_intervals[] = {
67	{   500,	 0 },
68	{  1000,	 1 },
69	{  2000,	 2 },
70	{  3000,	 3 },
71	{  4000,	 4 },
72	{  5000,	 5 },
73	{  6000,	 6 },
74	{  8000,	 7 },
75	{ 10000,	 8 },
76	{ 12000,	 9 },
77	{ 14000,	10 },
78	{ 16000,	11 },
79	{ 0,		 0 } /* sentinel */
80};
81
82static struct a10wd_softc *a10wd_sc = NULL;
83
84struct a10wd_softc {
85	device_t		dev;
86	struct resource *	res;
87	struct mtx		mtx;
88};
89
90static void a10wd_watchdog_fn(void *private, u_int cmd, int *error);
91
92static int
93a10wd_probe(device_t dev)
94{
95
96	if (ofw_bus_is_compatible(dev, "allwinner,sun4i-wdt")) {
97		device_set_desc(dev, "Allwinner A10 Watchdog");
98		return (BUS_PROBE_DEFAULT);
99	}
100
101	return (ENXIO);
102}
103
104static int
105a10wd_attach(device_t dev)
106{
107	struct a10wd_softc *sc;
108	int rid;
109
110	if (a10wd_sc != NULL)
111		return (ENXIO);
112
113	sc = device_get_softc(dev);
114	sc->dev = dev;
115
116	rid = 0;
117	sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
118	if (sc->res == NULL) {
119		device_printf(dev, "could not allocate memory resource\n");
120		return (ENXIO);
121	}
122
123	a10wd_sc = sc;
124	mtx_init(&sc->mtx, "A10 Watchdog", "a10wd", MTX_DEF);
125	EVENTHANDLER_REGISTER(watchdog_list, a10wd_watchdog_fn, sc, 0);
126
127	return (0);
128}
129
130static void
131a10wd_watchdog_fn(void *private, u_int cmd, int *error)
132{
133	struct a10wd_softc *sc;
134	uint64_t ms;
135	int i;
136
137	sc = private;
138	mtx_lock(&sc->mtx);
139
140	cmd &= WD_INTERVAL;
141
142	if (cmd > 0) {
143		ms = ((uint64_t)1 << (cmd & WD_INTERVAL)) / 1000000;
144		i = 0;
145		while (wd_intervals[i].milliseconds &&
146		    (ms > wd_intervals[i].milliseconds))
147			i++;
148		if (wd_intervals[i].milliseconds) {
149			WRITE(sc, WDOG_MODE,
150			    (wd_intervals[i].value << WDOG_MODE_INTVL_SHIFT) |
151			    WDOG_MODE_EN | WDOG_MODE_RST_EN);
152			WRITE(sc, WDOG_CTRL, WDOG_CTRL_RESTART);
153		}
154	}
155	else
156		WRITE(sc, WDOG_MODE, 0);
157
158	mtx_unlock(&sc->mtx);
159}
160
161void
162a10wd_watchdog_reset()
163{
164
165	if (a10wd_sc == NULL) {
166		printf("Reset: watchdog device has not been initialized\n");
167		return;
168	}
169
170	WRITE(a10wd_sc, WDOG_MODE,
171	    (wd_intervals[0].value << WDOG_MODE_INTVL_SHIFT) |
172	    WDOG_MODE_EN | WDOG_MODE_RST_EN);
173
174	while(1)
175		;
176
177}
178
179static device_method_t a10wd_methods[] = {
180	DEVMETHOD(device_probe, a10wd_probe),
181	DEVMETHOD(device_attach, a10wd_attach),
182
183	DEVMETHOD_END
184};
185
186static driver_t a10wd_driver = {
187	"a10wd",
188	a10wd_methods,
189	sizeof(struct a10wd_softc),
190};
191static devclass_t a10wd_devclass;
192
193DRIVER_MODULE(a10wd, simplebus, a10wd_driver, a10wd_devclass, 0, 0);
194