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_status_okay(dev))
97		return (ENXIO);
98
99	if (ofw_bus_is_compatible(dev, "allwinner,sun4i-wdt")) {
100		device_set_desc(dev, "Allwinner A10 Watchdog");
101		return (BUS_PROBE_DEFAULT);
102	}
103
104	return (ENXIO);
105}
106
107static int
108a10wd_attach(device_t dev)
109{
110	struct a10wd_softc *sc;
111	int rid;
112
113	if (a10wd_sc != NULL)
114		return (ENXIO);
115
116	sc = device_get_softc(dev);
117	sc->dev = dev;
118
119	rid = 0;
120	sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
121	if (sc->res == NULL) {
122		device_printf(dev, "could not allocate memory resource\n");
123		return (ENXIO);
124	}
125
126	a10wd_sc = sc;
127	mtx_init(&sc->mtx, "A10 Watchdog", "a10wd", MTX_DEF);
128	EVENTHANDLER_REGISTER(watchdog_list, a10wd_watchdog_fn, sc, 0);
129
130	return (0);
131}
132
133static void
134a10wd_watchdog_fn(void *private, u_int cmd, int *error)
135{
136	struct a10wd_softc *sc;
137	uint64_t ms;
138	int i;
139
140	sc = private;
141	mtx_lock(&sc->mtx);
142
143	cmd &= WD_INTERVAL;
144
145	if (cmd > 0) {
146		ms = ((uint64_t)1 << (cmd & WD_INTERVAL)) / 1000000;
147		i = 0;
148		while (wd_intervals[i].milliseconds &&
149		    (ms > wd_intervals[i].milliseconds))
150			i++;
151		if (wd_intervals[i].milliseconds) {
152			WRITE(sc, WDOG_MODE,
153			    (wd_intervals[i].value << WDOG_MODE_INTVL_SHIFT) |
154			    WDOG_MODE_EN | WDOG_MODE_RST_EN);
155			WRITE(sc, WDOG_CTRL, WDOG_CTRL_RESTART);
156			*error = 0;
157		}
158		else {
159			/*
160			 * Can't arm
161			 * disable watchdog as watchdog(9) requires
162			 */
163			device_printf(sc->dev,
164			    "Can't arm, timeout is more than 16 sec\n");
165			mtx_unlock(&sc->mtx);
166			WRITE(sc, WDOG_MODE, 0);
167			return;
168		}
169	}
170	else
171		WRITE(sc, WDOG_MODE, 0);
172
173	mtx_unlock(&sc->mtx);
174}
175
176void
177a10wd_watchdog_reset()
178{
179
180	if (a10wd_sc == NULL) {
181		printf("Reset: watchdog device has not been initialized\n");
182		return;
183	}
184
185	WRITE(a10wd_sc, WDOG_MODE,
186	    (wd_intervals[0].value << WDOG_MODE_INTVL_SHIFT) |
187	    WDOG_MODE_EN | WDOG_MODE_RST_EN);
188
189	while(1)
190		;
191
192}
193
194static device_method_t a10wd_methods[] = {
195	DEVMETHOD(device_probe, a10wd_probe),
196	DEVMETHOD(device_attach, a10wd_attach),
197
198	DEVMETHOD_END
199};
200
201static driver_t a10wd_driver = {
202	"a10wd",
203	a10wd_methods,
204	sizeof(struct a10wd_softc),
205};
206static devclass_t a10wd_devclass;
207
208DRIVER_MODULE(a10wd, simplebus, a10wd_driver, a10wd_devclass, 0, 0);
209