/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) 2013 Ganbold Tsagaankhuu <ganbold@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/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 <machine/fdt.h>

#include <arm/rockchip/rk30xx_wdog.h>

#ifndef	RK30_WDT_BASE
#define	RK30_WDT_BASE		0x2004c000
#define	RK30_WDT_PSIZE		0x100
#endif

#define	RK30_WDT_READ(_sc, _r)		bus_read_4((_sc)->res, (_r))
#define	RK30_WDT_WRITE(_sc, _r, _v)	bus_write_4((_sc)->res, (_r), (_v))

#define	WDOG_CTRL		0x00
#define	WDOG_CTRL_EN		(1 << 0)
#define	WDOG_CTRL_RSP_MODE	(1 << 1)
#define	WDOG_CTRL_RST_PULSE	(4 << 2)
#define	WDOG_CTRL_RST		0xa
#define	WDOG_TORR		0x04
#define	WDOG_TORR_INTVL_SHIFT	0
#define	WDOG_CCVR		0x08
#define	WDOG_CRR		0x0c
#define	WDOG_CRR_PWD		0x76
#define	WDOG_STAT		0x10
#define	WDOG_EOI		0x14

static struct rk30_wd_softc *rk30_wd_sc = NULL;

struct rk30_wd_softc {
	device_t		dev;
	struct resource		*res;
	struct mtx		mtx;
	int			freq;
};

static void rk30_wd_watchdog_fn(void *private, u_int cmd, int *error);

static int
rk30_wd_probe(device_t dev)
{

	if (!ofw_bus_status_okay(dev))
		return (ENXIO);

	if (ofw_bus_is_compatible(dev, "rockchip,rk30xx-wdt")) {
		device_set_desc(dev, "Rockchip RK30XX Watchdog");
		return (BUS_PROBE_DEFAULT);
	}

	return (ENXIO);
}

static int
rk30_wd_attach(device_t dev)
{
	struct rk30_wd_softc *sc;
	int rid;
	phandle_t node;
	pcell_t cell;

	if (rk30_wd_sc != NULL)
		return (ENXIO);

	sc = device_get_softc(dev);
	sc->dev = dev;

	node = ofw_bus_get_node(sc->dev);
	if (OF_getencprop(node, "clock-frequency", &cell, sizeof(cell)) > 0)
		sc->freq = cell / 1000000;
	else
		return (ENXIO);

	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);
	}

	rk30_wd_sc = sc;
	mtx_init(&sc->mtx, "RK30XX Watchdog", "rk30_wd", MTX_DEF);
	EVENTHANDLER_REGISTER(watchdog_list, rk30_wd_watchdog_fn, sc, 0);

	return (0);
}

static void
rk30_wd_watchdog_fn(void *private, u_int cmd, int *error)
{
	struct rk30_wd_softc *sc;
	uint64_t ms, m, max;
	int i;

	sc = private;
	mtx_lock(&sc->mtx);

	cmd &= WD_INTERVAL;

	if (cmd > 0) {
		ms = ((uint64_t)1 << (cmd & WD_INTERVAL)) / 1000000;
		m = 0xffff / sc->freq;
		max = 0x7fffffff / sc->freq + 1;
		i = 0;
		while (m < max && m < ms) {
			m <<= 1;
			i++;
		}
		if (m < max) {
			RK30_WDT_WRITE(sc, WDOG_TORR,
			    i << WDOG_TORR_INTVL_SHIFT);
			RK30_WDT_WRITE(sc, WDOG_CTRL,
			    WDOG_CTRL_EN | WDOG_CTRL_RSP_MODE |
			    WDOG_CTRL_RST_PULSE);
			RK30_WDT_WRITE(sc, WDOG_CRR, WDOG_CRR_PWD);
			*error = 0;
		} else {
			device_printf(sc->dev, "Can not be disabled\n");
			mtx_unlock(&sc->mtx);
			RK30_WDT_WRITE(sc, WDOG_CTRL, WDOG_CTRL_RST);
			return;
		}
	}
	else
		RK30_WDT_WRITE(sc, WDOG_CTRL, WDOG_CTRL_RST);

	mtx_unlock(&sc->mtx);
}

void
rk30_wd_watchdog_reset(void)
{
	bus_space_handle_t bsh;

	bus_space_map(fdtbus_bs_tag, RK30_WDT_BASE, RK30_WDT_PSIZE, 0, &bsh);
	bus_space_write_4(fdtbus_bs_tag, bsh, WDOG_TORR, 0);
	bus_space_write_4(fdtbus_bs_tag, bsh, WDOG_CTRL,
	    WDOG_CTRL_EN | WDOG_CTRL_RSP_MODE | WDOG_CTRL_RST_PULSE);

	while (1);
}

static device_method_t rk30_wd_methods[] = {
	DEVMETHOD(device_probe, rk30_wd_probe),
	DEVMETHOD(device_attach, rk30_wd_attach),

	DEVMETHOD_END
};

static driver_t rk30_wd_driver = {
	"rk30_wd",
	rk30_wd_methods,
	sizeof(struct rk30_wd_softc),
};
static devclass_t rk30_wd_devclass;

DRIVER_MODULE(rk30_wd, simplebus, rk30_wd_driver, rk30_wd_devclass, 0, 0);