2 * Copyright (c) 2010 Greg Ansley. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
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.
13 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * The SAM9 watchdog hardware can be programed only once. So we set the
28 * hardware watchdog to 16 s in wdt_attach and only reset it in the wdt_tick
29 * handler. The watchdog is halted in processor debug mode.
32 #include "opt_platform.h"
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
37 #include <sys/param.h>
40 #include <sys/kernel.h>
41 #include <sys/module.h>
42 #include <sys/systm.h>
43 #include <sys/watchdog.h>
45 #include <machine/bus.h>
47 #include <arm/at91/at91var.h>
48 #include <arm/at91/at91_wdtreg.h>
51 #include <dev/ofw/ofw_bus.h>
52 #include <dev/ofw/ofw_bus_subr.h>
58 struct resource *mem_res;
59 struct callout tick_ch;
60 eventhandler_tag sc_wet;
66 static inline uint32_t
67 RD4(struct wdt_softc *sc, bus_size_t off)
70 return (bus_read_4(sc->mem_res, off));
74 WR4(struct wdt_softc *sc, bus_size_t off, uint32_t val)
77 bus_write_4(sc->mem_res, off, val);
83 struct wdt_softc *sc = argp;
86 if (RD4(sc, WDT_SR) & (WDT_WDUNF | WDT_WDERR)) {
87 #if defined(KDB) && !defined(KDB_UNATTENDED)
89 kdb_enter(KDB_WHY_WATCHDOG, "watchdog timeout");
91 panic("watchdog timeout");
94 return (FILTER_STRAY);
97 /* User interface, see watchdog(9) */
99 wdt_watchdog(void *argp, u_int cmd, int *error)
101 struct wdt_softc *sc = argp;
104 mtx_lock(&sc->sc_mtx);
108 interval = cmd & WD_INTERVAL;
109 if (interval > WD_TO_16SEC)
111 else if (interval > 0)
112 sc->cmd = interval | WD_ACTIVE;
114 /* We cannot turn off our watchdog so if user
115 * fails to turn us on go to passive mode. */
116 if ((sc->cmd & WD_ACTIVE) == 0)
117 sc->cmd = WD_PASSIVE;
119 mtx_unlock(&sc->sc_mtx);
122 /* This routine is called no matter what state the user sets the
123 * watchdog mode to. Called at a rate that is slightly less than
124 * half the hardware timeout. */
128 struct wdt_softc *sc = argp;
130 mtx_assert(&sc->sc_mtx, MA_OWNED);
131 if (sc->cmd & (WD_ACTIVE | WD_PASSIVE))
132 WR4(sc, WDT_CR, WDT_KEY|WDT_WDRSTT);
134 sc->cmd &= WD_PASSIVE;
135 callout_reset(&sc->tick_ch, sc->interval, wdt_tick, sc);
139 wdt_probe(device_t dev)
142 if (!ofw_bus_is_compatible(dev, "atmel,at91sam9260-wdt"))
145 device_set_desc(dev, "WDT");
150 wdt_attach(device_t dev)
152 static struct wdt_softc *sc;
153 struct resource *irq;
157 sc = device_get_softc(dev);
158 sc->cmd = WD_PASSIVE;
161 mtx_init(&sc->sc_mtx, device_get_nameunit(dev), "at91_wdt", MTX_DEF);
162 callout_init_mtx(&sc->tick_ch, &sc->sc_mtx, 0);
165 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
168 if (sc->mem_res == NULL)
169 panic("couldn't allocate wdt register resources");
171 wdt_mr = RD4(sc, WDT_MR);
172 if ((wdt_mr & WDT_WDRSTEN) == 0)
173 device_printf(dev, "Watchdog disabled! (Boot ROM?)\n");
176 /* Rude, full reset of whole system on watch dog timeout */
177 WR4(sc, WDT_MR, WDT_WDDBGHLT | WDT_WDD(0xC00)|
178 WDT_WDRSTEN| WDT_WDV(0xFFF));
180 /* Generate stack trace and panic on watchdog timeout*/
181 WR4(sc, WDT_MR, WDT_WDDBGHLT | WDT_WDD(0xC00)|
182 WDT_WDFIEN| WDT_WDV(0xFFF));
185 * This may have been set by Boot ROM so register value may
186 * not be what we just requested since this is a write once
189 wdt_mr = RD4(sc, WDT_MR);
190 if (wdt_mr & WDT_WDFIEN) {
192 irq = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
193 RF_ACTIVE | RF_SHAREABLE);
195 panic("could not allocate interrupt.\n");
197 err = bus_setup_intr(dev, irq, INTR_TYPE_CLK, wdt_intr,
198 NULL, sc, &sc->intrhand);
202 sc->interval = (((wdt_mr & WDT_WDV(~0)) + 1) * WDT_DIV) /
205 device_printf(dev, "watchdog timeout: %d seconds\n",
208 /* Slightly less than 1/2 of watchdog hardware timeout */
209 sc->interval = (sc->interval/2) - (sc->interval/20);
210 callout_reset(&sc->tick_ch, sc->interval, wdt_tick, sc);
212 /* Register us as a watchdog */
213 sc->sc_wet = EVENTHANDLER_REGISTER(watchdog_list,
214 wdt_watchdog, sc, 0);
219 static device_method_t wdt_methods[] = {
220 DEVMETHOD(device_probe, wdt_probe),
221 DEVMETHOD(device_attach, wdt_attach),
225 static driver_t wdt_driver = {
228 sizeof(struct wdt_softc),
231 static devclass_t wdt_devclass;
234 DRIVER_MODULE(at91_wdt, simplebus, wdt_driver, wdt_devclass, NULL, NULL);
236 DRIVER_MODULE(at91_wdt, atmelarm, wdt_driver, wdt_devclass, NULL, NULL);