freebsd-nq/sys/arm/at91/at91_wdt.c
Pedro F. Giffuni af3dc4a7ca sys/arm: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-27 15:04:10 +00:00

240 lines
6.1 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2010 Greg Ansley. 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 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 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.
*/
/*
* The SAM9 watchdog hardware can be programed only once. So we set the
* hardware watchdog to 16 s in wdt_attach and only reset it in the wdt_tick
* handler. The watchdog is halted in processor debug mode.
*/
#include "opt_platform.h"
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/systm.h>
#include <sys/watchdog.h>
#include <machine/bus.h>
#include <arm/at91/at91var.h>
#include <arm/at91/at91_wdtreg.h>
#ifdef FDT
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#endif
struct wdt_softc {
struct mtx sc_mtx;
device_t sc_dev;
struct resource *mem_res;
struct callout tick_ch;
eventhandler_tag sc_wet;
void *intrhand;
u_int cmd;
u_int interval;
};
static inline uint32_t
RD4(struct wdt_softc *sc, bus_size_t off)
{
return (bus_read_4(sc->mem_res, off));
}
static inline void
WR4(struct wdt_softc *sc, bus_size_t off, uint32_t val)
{
bus_write_4(sc->mem_res, off, val);
}
static int
wdt_intr(void *argp)
{
struct wdt_softc *sc = argp;
if (RD4(sc, WDT_SR) & (WDT_WDUNF | WDT_WDERR)) {
#if defined(KDB) && !defined(KDB_UNATTENDED)
kdb_backtrace();
kdb_enter(KDB_WHY_WATCHDOG, "watchdog timeout");
#else
panic("watchdog timeout");
#endif
}
return (FILTER_STRAY);
}
/* User interface, see watchdog(9) */
static void
wdt_watchdog(void *argp, u_int cmd, int *error)
{
struct wdt_softc *sc = argp;
u_int interval;
mtx_lock(&sc->sc_mtx);
*error = 0;
sc->cmd = 0;
interval = cmd & WD_INTERVAL;
if (interval > WD_TO_16SEC)
*error = EOPNOTSUPP;
else if (interval > 0)
sc->cmd = interval | WD_ACTIVE;
/* We cannot turn off our watchdog so if user
* fails to turn us on go to passive mode. */
if ((sc->cmd & WD_ACTIVE) == 0)
sc->cmd = WD_PASSIVE;
mtx_unlock(&sc->sc_mtx);
}
/* This routine is called no matter what state the user sets the
* watchdog mode to. Called at a rate that is slightly less than
* half the hardware timeout. */
static void
wdt_tick(void *argp)
{
struct wdt_softc *sc = argp;
mtx_assert(&sc->sc_mtx, MA_OWNED);
if (sc->cmd & (WD_ACTIVE | WD_PASSIVE))
WR4(sc, WDT_CR, WDT_KEY|WDT_WDRSTT);
sc->cmd &= WD_PASSIVE;
callout_reset(&sc->tick_ch, sc->interval, wdt_tick, sc);
}
static int
wdt_probe(device_t dev)
{
#ifdef FDT
if (!ofw_bus_is_compatible(dev, "atmel,at91sam9260-wdt"))
return (ENXIO);
#endif
device_set_desc(dev, "WDT");
return (0);
}
static int
wdt_attach(device_t dev)
{
static struct wdt_softc *sc;
struct resource *irq;
uint32_t wdt_mr;
int rid, err;
sc = device_get_softc(dev);
sc->cmd = WD_PASSIVE;
sc->sc_dev = dev;
mtx_init(&sc->sc_mtx, device_get_nameunit(dev), "at91_wdt", MTX_DEF);
callout_init_mtx(&sc->tick_ch, &sc->sc_mtx, 0);
rid = 0;
sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
RF_ACTIVE);
if (sc->mem_res == NULL)
panic("couldn't allocate wdt register resources");
wdt_mr = RD4(sc, WDT_MR);
if ((wdt_mr & WDT_WDRSTEN) == 0)
device_printf(dev, "Watchdog disabled! (Boot ROM?)\n");
else {
#ifdef WDT_RESET
/* Rude, full reset of whole system on watch dog timeout */
WR4(sc, WDT_MR, WDT_WDDBGHLT | WDT_WDD(0xC00)|
WDT_WDRSTEN| WDT_WDV(0xFFF));
#else
/* Generate stack trace and panic on watchdog timeout*/
WR4(sc, WDT_MR, WDT_WDDBGHLT | WDT_WDD(0xC00)|
WDT_WDFIEN| WDT_WDV(0xFFF));
#endif
/*
* This may have been set by Boot ROM so register value may
* not be what we just requested since this is a write once
* register.
*/
wdt_mr = RD4(sc, WDT_MR);
if (wdt_mr & WDT_WDFIEN) {
rid = 0;
irq = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
RF_ACTIVE | RF_SHAREABLE);
if (!irq)
panic("could not allocate interrupt.\n");
err = bus_setup_intr(dev, irq, INTR_TYPE_CLK, wdt_intr,
NULL, sc, &sc->intrhand);
}
/* interval * hz */
sc->interval = (((wdt_mr & WDT_WDV(~0)) + 1) * WDT_DIV) /
(WDT_CLOCK/hz);
device_printf(dev, "watchdog timeout: %d seconds\n",
sc->interval / hz);
/* Slightly less than 1/2 of watchdog hardware timeout */
sc->interval = (sc->interval/2) - (sc->interval/20);
callout_reset(&sc->tick_ch, sc->interval, wdt_tick, sc);
/* Register us as a watchdog */
sc->sc_wet = EVENTHANDLER_REGISTER(watchdog_list,
wdt_watchdog, sc, 0);
}
return (0);
}
static device_method_t wdt_methods[] = {
DEVMETHOD(device_probe, wdt_probe),
DEVMETHOD(device_attach, wdt_attach),
DEVMETHOD_END
};
static driver_t wdt_driver = {
"at91_wdt",
wdt_methods,
sizeof(struct wdt_softc),
};
static devclass_t wdt_devclass;
#ifdef FDT
DRIVER_MODULE(at91_wdt, simplebus, wdt_driver, wdt_devclass, NULL, NULL);
#else
DRIVER_MODULE(at91_wdt, atmelarm, wdt_driver, wdt_devclass, NULL, NULL);
#endif