/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2012 Alexander Rybalko * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define BCM2835_PASSWORD 0x5a #define BCM2835_WDOG_RESET 0 #define BCM2835_PASSWORD_MASK 0xff000000 #define BCM2835_PASSWORD_SHIFT 24 #define BCM2835_WDOG_TIME_MASK 0x000fffff #define BCM2835_WDOG_TIME_SHIFT 0 #define READ(_sc, _r) bus_space_read_4((_sc)->bst, (_sc)->bsh, (_r) + (_sc)->regs_offset) #define WRITE(_sc, _r, _v) bus_space_write_4((_sc)->bst, (_sc)->bsh, (_r) + (_sc)->regs_offset, (_v)) #define BCM2835_RSTC_WRCFG_CLR 0xffffffcf #define BCM2835_RSTC_WRCFG_SET 0x00000030 #define BCM2835_RSTC_WRCFG_FULL_RESET 0x00000020 #define BCM2835_RSTC_RESET 0x00000102 #define BCM2835_RSTC_REG 0x00 #define BCM2835_RSTS_REG 0x04 #define BCM2835_WDOG_REG 0x08 static struct bcmwd_softc *bcmwd_lsc = NULL; struct bcmwd_softc { device_t dev; struct resource * res; bus_space_tag_t bst; bus_space_handle_t bsh; int wdog_armed; int wdog_period; char wdog_passwd; struct mtx mtx; int regs_offset; }; #define BSD_DTB 1 #define UPSTREAM_DTB 2 #define UPSTREAM_DTB_REGS_OFFSET 0x1c static struct ofw_compat_data compat_data[] = { {"broadcom,bcm2835-wdt", BSD_DTB}, {"brcm,bcm2835-pm-wdt", UPSTREAM_DTB}, {"brcm,bcm2835-pm", UPSTREAM_DTB}, {NULL, 0} }; static void bcmwd_watchdog_fn(void *private, u_int cmd, int *error); static void bcmwd_reboot_system(void *, int); static int bcmwd_probe(device_t dev) { if (!ofw_bus_status_okay(dev)) return (ENXIO); if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0) return (ENXIO); device_set_desc(dev, "BCM2708/2835 Watchdog"); return (BUS_PROBE_DEFAULT); } static int bcmwd_attach(device_t dev) { struct bcmwd_softc *sc; int rid; if (bcmwd_lsc != NULL) return (ENXIO); sc = device_get_softc(dev); sc->wdog_period = 7; sc->wdog_passwd = BCM2835_PASSWORD; sc->wdog_armed = 0; sc->dev = dev; rid = 0; sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE); if (sc->res == NULL) { device_printf(dev, "could not allocate memory resource\n"); return (ENXIO); } sc->bst = rman_get_bustag(sc->res); sc->bsh = rman_get_bushandle(sc->res); /* compensate base address difference */ if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == UPSTREAM_DTB) sc->regs_offset = UPSTREAM_DTB_REGS_OFFSET; bcmwd_lsc = sc; mtx_init(&sc->mtx, "BCM2835 Watchdog", "bcmwd", MTX_DEF); EVENTHANDLER_REGISTER(watchdog_list, bcmwd_watchdog_fn, sc, 0); /* * Handle reboot events. This needs to happen with slightly greater * priority than the PSCI handler, since PSCI reset is not properly * implemented on the Pi and it just puts the Pi into a halt * state. */ EVENTHANDLER_REGISTER(shutdown_final, bcmwd_reboot_system, sc, SHUTDOWN_PRI_LAST-1); return (0); } static void bcmwd_watchdog_fn(void *private, u_int cmd, int *error) { struct bcmwd_softc *sc; uint64_t sec; uint32_t ticks, reg; sc = private; mtx_lock(&sc->mtx); cmd &= WD_INTERVAL; if (cmd > 0) { sec = ((uint64_t)1 << (cmd & WD_INTERVAL)) / 1000000000; if (sec == 0 || sec > 15) { /* * Can't arm * disable watchdog as watchdog(9) requires */ device_printf(sc->dev, "Can't arm, timeout must be between 1-15 seconds\n"); WRITE(sc, BCM2835_RSTC_REG, (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | BCM2835_RSTC_RESET); mtx_unlock(&sc->mtx); *error = EINVAL; return; } ticks = (sec << 16) & BCM2835_WDOG_TIME_MASK; reg = (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | ticks; WRITE(sc, BCM2835_WDOG_REG, reg); reg = READ(sc, BCM2835_RSTC_REG); reg &= BCM2835_RSTC_WRCFG_CLR; reg |= BCM2835_RSTC_WRCFG_FULL_RESET; reg |= (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT); WRITE(sc, BCM2835_RSTC_REG, reg); *error = 0; } else WRITE(sc, BCM2835_RSTC_REG, (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | BCM2835_RSTC_RESET); mtx_unlock(&sc->mtx); } void bcmwd_watchdog_reset(void) { if (bcmwd_lsc == NULL) return; WRITE(bcmwd_lsc, BCM2835_WDOG_REG, (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | 10); WRITE(bcmwd_lsc, BCM2835_RSTC_REG, (READ(bcmwd_lsc, BCM2835_RSTC_REG) & BCM2835_RSTC_WRCFG_CLR) | (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | BCM2835_RSTC_WRCFG_FULL_RESET); } static void bcmwd_reboot_system(void *sc, int howto) { int cmd, error = 0; /* Only handle reset. */ if (howto & RB_HALT || howto & RB_POWEROFF) return; printf("Resetting system ... "); cmd = WD_TO_1SEC; bcmwd_watchdog_fn(sc, cmd, &error); /* Wait for watchdog timeout. */ DELAY(2000000); /* Not reached ... one hopes. */ printf("failed to reset (errno %d).\n", error); } static device_method_t bcmwd_methods[] = { DEVMETHOD(device_probe, bcmwd_probe), DEVMETHOD(device_attach, bcmwd_attach), DEVMETHOD_END }; static driver_t bcmwd_driver = { "bcmwd", bcmwd_methods, sizeof(struct bcmwd_softc), }; DRIVER_MODULE(bcmwd, simplebus, bcmwd_driver, 0, 0);