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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2012 Alexander Rybalko <ray@freebsd.org>
* 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/reboot.h>
#include <sys/rman.h>
#include <sys/systm.h>
#include <sys/watchdog.h>
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <machine/bus.h>
#include <machine/machdep.h>
#include <arm/broadcom/bcm2835/bcm2835_wdog.h>
#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),
};
static devclass_t bcmwd_devclass;
DRIVER_MODULE(bcmwd, simplebus, bcmwd_driver, bcmwd_devclass, 0, 0);
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