aw_wdog.c revision 309761 
1/*-
2 * Copyright (c) 2013 Oleksandr Tymoshenko <gonzo@freebsd.org>
3 * Copyright (c) 2016 Emmanuel Vadot <manu@bidouilliste.com>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: stable/11/sys/arm/allwinner/aw_wdog.c 309761 2016-12-09 20:28:28Z manu $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/watchdog.h>
33#include <sys/reboot.h>
34#include <sys/bus.h>
35#include <sys/kernel.h>
36#include <sys/lock.h>
37#include <sys/module.h>
38#include <sys/mutex.h>
39#include <sys/rman.h>
40
41#include <dev/fdt/fdt_common.h>
42#include <dev/ofw/openfirm.h>
43#include <dev/ofw/ofw_bus.h>
44#include <dev/ofw/ofw_bus_subr.h>
45
46#include <machine/bus.h>
47#include <machine/machdep.h>
48
49#include <arm/allwinner/aw_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	A10_WDOG_CTRL		0x00
55#define	A31_WDOG_CTRL		0x10
56#define	 WDOG_CTRL_RESTART	(1 << 0)
57#define	 A31_WDOG_CTRL_KEY	(0xa57 << 1)
58#define	A10_WDOG_MODE		0x04
59#define	A31_WDOG_MODE		0x18
60#define	 A10_WDOG_MODE_INTVL_SHIFT	3
61#define	 A31_WDOG_MODE_INTVL_SHIFT	4
62#define	 A10_WDOG_MODE_RST_EN	(1 << 1)
63#define	 WDOG_MODE_EN		(1 << 0)
64#define	A31_WDOG_CONFIG		0x14
65#define	 A31_WDOG_CONFIG_RST_EN_SYSTEM	(1 << 0)
66#define	 A31_WDOG_CONFIG_RST_EN_INT	(2 << 0)
67
68struct aw_wdog_interval {
69	uint64_t	milliseconds;
70	unsigned int	value;
71};
72
73struct aw_wdog_interval wd_intervals[] = {
74	{   500,	 0 },
75	{  1000,	 1 },
76	{  2000,	 2 },
77	{  3000,	 3 },
78	{  4000,	 4 },
79	{  5000,	 5 },
80	{  6000,	 6 },
81	{  8000,	 7 },
82	{ 10000,	 8 },
83	{ 12000,	 9 },
84	{ 14000,	10 },
85	{ 16000,	11 },
86	{ 0,		 0 } /* sentinel */
87};
88
89static struct aw_wdog_softc *aw_wdog_sc = NULL;
90
91struct aw_wdog_softc {
92	device_t		dev;
93	struct resource *	res;
94	struct mtx		mtx;
95	uint8_t			wdog_ctrl;
96	uint32_t		wdog_ctrl_key;
97	uint8_t			wdog_mode;
98	uint8_t			wdog_mode_intvl_shift;
99	uint8_t			wdog_mode_en;
100	uint8_t			wdog_config;
101	uint8_t			wdog_config_value;
102};
103
104#define	A10_WATCHDOG	1
105#define	A31_WATCHDOG	2
106
107static struct ofw_compat_data compat_data[] = {
108	{"allwinner,sun4i-a10-wdt", A10_WATCHDOG},
109	{"allwinner,sun6i-a31-wdt", A31_WATCHDOG},
110	{NULL,             0}
111};
112
113static void aw_wdog_watchdog_fn(void *, u_int, int *);
114static void aw_wdog_shutdown_fn(void *, int);
115
116static int
117aw_wdog_probe(device_t dev)
118{
119	struct aw_wdog_softc *sc;
120
121	sc = device_get_softc(dev);
122
123	if (!ofw_bus_status_okay(dev))
124		return (ENXIO);
125	switch (ofw_bus_search_compatible(dev, compat_data)->ocd_data) {
126	case A10_WATCHDOG:
127		device_set_desc(dev, "Allwinner A10 Watchdog");
128		return (BUS_PROBE_DEFAULT);
129	case A31_WATCHDOG:
130		device_set_desc(dev, "Allwinner A31 Watchdog");
131		return (BUS_PROBE_DEFAULT);
132	}
133	return (ENXIO);
134}
135
136static int
137aw_wdog_attach(device_t dev)
138{
139	struct aw_wdog_softc *sc;
140	int rid;
141
142	if (aw_wdog_sc != NULL)
143		return (ENXIO);
144
145	sc = device_get_softc(dev);
146	sc->dev = dev;
147
148	rid = 0;
149	sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
150	if (sc->res == NULL) {
151		device_printf(dev, "could not allocate memory resource\n");
152		return (ENXIO);
153	}
154
155	aw_wdog_sc = sc;
156
157	switch (ofw_bus_search_compatible(dev, compat_data)->ocd_data) {
158	case A10_WATCHDOG:
159		sc->wdog_ctrl = A10_WDOG_CTRL;
160		sc->wdog_mode = A10_WDOG_MODE;
161		sc->wdog_mode_intvl_shift = A10_WDOG_MODE_INTVL_SHIFT;
162		sc->wdog_mode_en = A10_WDOG_MODE_RST_EN | WDOG_MODE_EN;
163		break;
164	case A31_WATCHDOG:
165		sc->wdog_ctrl = A31_WDOG_CTRL;
166		sc->wdog_ctrl_key = A31_WDOG_CTRL_KEY;
167		sc->wdog_mode = A31_WDOG_MODE;
168		sc->wdog_mode_intvl_shift = A31_WDOG_MODE_INTVL_SHIFT;
169		sc->wdog_mode_en = WDOG_MODE_EN;
170		sc->wdog_config = A31_WDOG_CONFIG;
171		sc->wdog_config_value = A31_WDOG_CONFIG_RST_EN_SYSTEM;
172		break;
173	default:
174		bus_release_resource(dev, SYS_RES_MEMORY, rid, sc->res);
175		return (ENXIO);
176	}
177
178	mtx_init(&sc->mtx, "AW Watchdog", "aw_wdog", MTX_DEF);
179	EVENTHANDLER_REGISTER(watchdog_list, aw_wdog_watchdog_fn, sc, 0);
180	EVENTHANDLER_REGISTER(shutdown_final, aw_wdog_shutdown_fn, sc,
181	    SHUTDOWN_PRI_LAST - 1);
182
183	return (0);
184}
185
186static void
187aw_wdog_watchdog_fn(void *private, u_int cmd, int *error)
188{
189	struct aw_wdog_softc *sc;
190	uint64_t ms;
191	int i;
192
193	sc = private;
194	mtx_lock(&sc->mtx);
195
196	cmd &= WD_INTERVAL;
197
198	if (cmd > 0) {
199		ms = ((uint64_t)1 << (cmd & WD_INTERVAL)) / 1000000;
200		i = 0;
201		while (wd_intervals[i].milliseconds &&
202		    (ms > wd_intervals[i].milliseconds))
203			i++;
204		if (wd_intervals[i].milliseconds) {
205			WRITE(sc, sc->wdog_mode,
206			  (wd_intervals[i].value << sc->wdog_mode_intvl_shift) |
207			    sc->wdog_mode_en);
208			WRITE(sc, sc->wdog_ctrl,
209			    WDOG_CTRL_RESTART | sc->wdog_ctrl_key);
210			if (sc->wdog_config)
211				WRITE(sc, sc->wdog_config,
212				    sc->wdog_config_value);
213			*error = 0;
214		}
215		else {
216			/*
217			 * Can't arm
218			 * disable watchdog as watchdog(9) requires
219			 */
220			device_printf(sc->dev,
221			    "Can't arm, timeout is more than 16 sec\n");
222			mtx_unlock(&sc->mtx);
223			WRITE(sc, sc->wdog_mode, 0);
224			return;
225		}
226	}
227	else
228		WRITE(sc, sc->wdog_mode, 0);
229
230	mtx_unlock(&sc->mtx);
231}
232
233static void
234aw_wdog_shutdown_fn(void *private, int howto)
235{
236	if ((howto & (RB_POWEROFF|RB_HALT)) == 0)
237		aw_wdog_watchdog_reset();
238}
239
240void
241aw_wdog_watchdog_reset()
242{
243
244	if (aw_wdog_sc == NULL) {
245		printf("Reset: watchdog device has not been initialized\n");
246		return;
247	}
248
249	WRITE(aw_wdog_sc, aw_wdog_sc->wdog_mode,
250	    (wd_intervals[0].value << aw_wdog_sc->wdog_mode_intvl_shift) |
251	    aw_wdog_sc->wdog_mode_en);
252	if (aw_wdog_sc->wdog_config)
253		WRITE(aw_wdog_sc, aw_wdog_sc->wdog_config,
254		      aw_wdog_sc->wdog_config_value);
255	WRITE(aw_wdog_sc, aw_wdog_sc->wdog_ctrl,
256	    WDOG_CTRL_RESTART | aw_wdog_sc->wdog_ctrl_key);
257	while(1)
258		;
259
260}
261
262static device_method_t aw_wdog_methods[] = {
263	DEVMETHOD(device_probe, aw_wdog_probe),
264	DEVMETHOD(device_attach, aw_wdog_attach),
265
266	DEVMETHOD_END
267};
268
269static driver_t aw_wdog_driver = {
270	"aw_wdog",
271	aw_wdog_methods,
272	sizeof(struct aw_wdog_softc),
273};
274static devclass_t aw_wdog_devclass;
275
276DRIVER_MODULE(aw_wdog, simplebus, aw_wdog_driver, aw_wdog_devclass, 0, 0);
277