/*	$OpenBSD: syscon.c,v 1.1 2017/03/09 20:04:21 kettenis Exp $	*/
/*
 * Copyright (c) 2017 Mark Kettenis
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>

#include <machine/bus.h>
#include <machine/fdt.h>

#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_misc.h>
#include <dev/ofw/fdt.h>

extern void (*cpuresetfn)(void);
extern void (*powerdownfn)(void);

struct syscon_softc {
	struct device	sc_dev;
	uint32_t	sc_regmap;
	bus_size_t	sc_offset;
	uint32_t	sc_mask;
};

struct syscon_softc *syscon_reboot_sc;
struct syscon_softc *syscon_poweroff_sc;

int	syscon_match(struct device *, void *, void *);
void	syscon_attach(struct device *, struct device *, void *);

struct cfattach syscon_ca = {
	sizeof(struct syscon_softc), syscon_match, syscon_attach
};

struct cfdriver syscon_cd = {
	NULL, "syscon", DV_DULL
};

void	syscon_reset(void);
void	syscon_powerdown(void);

int
syscon_match(struct device *parent, void *match, void *aux)
{
	struct fdt_attach_args *faa = aux;

	return (OF_is_compatible(faa->fa_node, "syscon-reboot") ||
	    OF_is_compatible(faa->fa_node, "syscon-poweroff"));
}

void
syscon_attach(struct device *parent, struct device *self, void *aux)
{
	struct syscon_softc *sc = (struct syscon_softc *)self;
	struct fdt_attach_args *faa = aux;

	printf("\n");

	sc->sc_regmap = OF_getpropint(faa->fa_node, "regmap", 0);
	if (sc->sc_regmap == 0)
		return;

	if (OF_getproplen(faa->fa_node, "offset") != sizeof(uint32_t) ||
	    OF_getproplen(faa->fa_node, "mask") != sizeof(uint32_t))
		return;

	sc->sc_offset = OF_getpropint(faa->fa_node, "offset", 0);
	sc->sc_mask = OF_getpropint(faa->fa_node, "mask", 0);

	if (OF_is_compatible(faa->fa_node, "syscon-reboot")) {
		syscon_reboot_sc = sc;
		cpuresetfn = syscon_reset;
	} else {
		syscon_poweroff_sc = sc;
		powerdownfn = syscon_powerdown;
	}
}

void
syscon_reset(void)
{
	struct syscon_softc *sc = syscon_reboot_sc;
	struct regmap *rm;

	rm = regmap_byphandle(sc->sc_regmap);
	if (rm == NULL)
		return;

	regmap_write_4(rm, sc->sc_offset, sc->sc_mask);
	delay(1000000);
}

void
syscon_powerdown(void)
{
	struct syscon_softc *sc = syscon_poweroff_sc;
	struct regmap *rm;

	rm = regmap_byphandle(sc->sc_regmap);
	if (rm == NULL)
		return;

	regmap_write_4(rm, sc->sc_offset, sc->sc_mask);
	delay(1000000);
}