freebsd-dev/sys/arm/allwinner/a10_wdog.c
Oleksandr Tymoshenko 5ad43f4b9a Make watchdog function conform watchdog(9):
Set error to 0 when watchdog is armed and disable it when timeout
is too large to be set.
2013-10-22 05:22:46 +00:00

206 lines
4.8 KiB
C

/*-
* Copyright (c) 2013 Oleksandr Tymoshenko <gonzo@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/systm.h>
#include <sys/watchdog.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/rman.h>
#include <dev/fdt/fdt_common.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/cpufunc.h>
#include <machine/machdep.h>
#include <machine/fdt.h>
#include <arm/allwinner/a10_wdog.h>
#define READ(_sc, _r) bus_read_4((_sc)->res, (_r))
#define WRITE(_sc, _r, _v) bus_write_4((_sc)->res, (_r), (_v))
#define WDOG_CTRL 0x00
#define WDOG_CTRL_RESTART (1 << 0)
#define WDOG_MODE 0x04
#define WDOG_MODE_INTVL_SHIFT 3
#define WDOG_MODE_RST_EN (1 << 1)
#define WDOG_MODE_EN (1 << 0)
struct a10wd_interval {
uint64_t milliseconds;
unsigned int value;
};
struct a10wd_interval wd_intervals[] = {
{ 500, 0 },
{ 1000, 1 },
{ 2000, 2 },
{ 3000, 3 },
{ 4000, 4 },
{ 5000, 5 },
{ 6000, 6 },
{ 8000, 7 },
{ 10000, 8 },
{ 12000, 9 },
{ 14000, 10 },
{ 16000, 11 },
{ 0, 0 } /* sentinel */
};
static struct a10wd_softc *a10wd_sc = NULL;
struct a10wd_softc {
device_t dev;
struct resource * res;
struct mtx mtx;
};
static void a10wd_watchdog_fn(void *private, u_int cmd, int *error);
static int
a10wd_probe(device_t dev)
{
if (ofw_bus_is_compatible(dev, "allwinner,sun4i-wdt")) {
device_set_desc(dev, "Allwinner A10 Watchdog");
return (BUS_PROBE_DEFAULT);
}
return (ENXIO);
}
static int
a10wd_attach(device_t dev)
{
struct a10wd_softc *sc;
int rid;
if (a10wd_sc != NULL)
return (ENXIO);
sc = device_get_softc(dev);
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);
}
a10wd_sc = sc;
mtx_init(&sc->mtx, "A10 Watchdog", "a10wd", MTX_DEF);
EVENTHANDLER_REGISTER(watchdog_list, a10wd_watchdog_fn, sc, 0);
return (0);
}
static void
a10wd_watchdog_fn(void *private, u_int cmd, int *error)
{
struct a10wd_softc *sc;
uint64_t ms;
int i;
sc = private;
mtx_lock(&sc->mtx);
cmd &= WD_INTERVAL;
if (cmd > 0) {
ms = ((uint64_t)1 << (cmd & WD_INTERVAL)) / 1000000;
i = 0;
while (wd_intervals[i].milliseconds &&
(ms > wd_intervals[i].milliseconds))
i++;
if (wd_intervals[i].milliseconds) {
WRITE(sc, WDOG_MODE,
(wd_intervals[i].value << WDOG_MODE_INTVL_SHIFT) |
WDOG_MODE_EN | WDOG_MODE_RST_EN);
WRITE(sc, WDOG_CTRL, WDOG_CTRL_RESTART);
*error = 0;
}
else {
/*
* Can't arm
* disable watchdog as watchdog(9) requires
*/
device_printf(sc->dev,
"Can't arm, timeout is more than 16 sec\n");
mtx_unlock(&sc->mtx);
WRITE(sc, WDOG_MODE, 0);
return;
}
}
else
WRITE(sc, WDOG_MODE, 0);
mtx_unlock(&sc->mtx);
}
void
a10wd_watchdog_reset()
{
if (a10wd_sc == NULL) {
printf("Reset: watchdog device has not been initialized\n");
return;
}
WRITE(a10wd_sc, WDOG_MODE,
(wd_intervals[0].value << WDOG_MODE_INTVL_SHIFT) |
WDOG_MODE_EN | WDOG_MODE_RST_EN);
while(1)
;
}
static device_method_t a10wd_methods[] = {
DEVMETHOD(device_probe, a10wd_probe),
DEVMETHOD(device_attach, a10wd_attach),
DEVMETHOD_END
};
static driver_t a10wd_driver = {
"a10wd",
a10wd_methods,
sizeof(struct a10wd_softc),
};
static devclass_t a10wd_devclass;
DRIVER_MODULE(a10wd, simplebus, a10wd_driver, a10wd_devclass, 0, 0);