/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2013 Nathan Whitehorn
 * 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/param.h>
#include <sys/systm.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/rman.h>

#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>

#include <dev/fdt/simplebus.h>

/*
 * Bus interface.
 */
static int		simplebus_probe(device_t dev);
static struct resource *simplebus_alloc_resource(device_t, device_t, int,
    int *, rman_res_t, rman_res_t, rman_res_t, u_int);
static void		simplebus_probe_nomatch(device_t bus, device_t child);
static int		simplebus_print_child(device_t bus, device_t child);
static device_t		simplebus_add_child(device_t dev, u_int order,
    const char *name, int unit);
static struct resource_list *simplebus_get_resource_list(device_t bus,
    device_t child);

static ssize_t		simplebus_get_property(device_t bus, device_t child,
    const char *propname, void *propvalue, size_t size,
    device_property_type_t type);
/*
 * ofw_bus interface
 */
static const struct ofw_bus_devinfo *simplebus_get_devinfo(device_t bus,
    device_t child);

/*
 * Driver methods.
 */
static device_method_t	simplebus_methods[] = {
	/* Device interface */
	DEVMETHOD(device_probe,		simplebus_probe),
	DEVMETHOD(device_attach,	simplebus_attach),
	DEVMETHOD(device_detach,	simplebus_detach),
	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
	DEVMETHOD(device_suspend,	bus_generic_suspend),
	DEVMETHOD(device_resume,	bus_generic_resume),

	/* Bus interface */
	DEVMETHOD(bus_add_child,	simplebus_add_child),
	DEVMETHOD(bus_print_child,	simplebus_print_child),
	DEVMETHOD(bus_probe_nomatch,	simplebus_probe_nomatch),
	DEVMETHOD(bus_read_ivar,	bus_generic_read_ivar),
	DEVMETHOD(bus_write_ivar,	bus_generic_write_ivar),
	DEVMETHOD(bus_setup_intr,	bus_generic_setup_intr),
	DEVMETHOD(bus_teardown_intr,	bus_generic_teardown_intr),
	DEVMETHOD(bus_alloc_resource,	simplebus_alloc_resource),
	DEVMETHOD(bus_release_resource,	bus_generic_release_resource),
	DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
	DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
	DEVMETHOD(bus_adjust_resource,	bus_generic_adjust_resource),
	DEVMETHOD(bus_map_resource,	bus_generic_map_resource),
	DEVMETHOD(bus_unmap_resource,	bus_generic_unmap_resource),
	DEVMETHOD(bus_set_resource,	bus_generic_rl_set_resource),
	DEVMETHOD(bus_get_resource,	bus_generic_rl_get_resource),
	DEVMETHOD(bus_delete_resource,	bus_generic_rl_delete_resource),
	DEVMETHOD(bus_child_pnpinfo,	ofw_bus_gen_child_pnpinfo),
	DEVMETHOD(bus_get_resource_list, simplebus_get_resource_list),
	DEVMETHOD(bus_get_property,	simplebus_get_property),
	DEVMETHOD(bus_get_device_path,  ofw_bus_gen_get_device_path),

	/* ofw_bus interface */
	DEVMETHOD(ofw_bus_get_devinfo,	simplebus_get_devinfo),
	DEVMETHOD(ofw_bus_get_compat,	ofw_bus_gen_get_compat),
	DEVMETHOD(ofw_bus_get_model,	ofw_bus_gen_get_model),
	DEVMETHOD(ofw_bus_get_name,	ofw_bus_gen_get_name),
	DEVMETHOD(ofw_bus_get_node,	ofw_bus_gen_get_node),
	DEVMETHOD(ofw_bus_get_type,	ofw_bus_gen_get_type),

	DEVMETHOD_END
};

DEFINE_CLASS_0(simplebus, simplebus_driver, simplebus_methods,
    sizeof(struct simplebus_softc));

EARLY_DRIVER_MODULE(simplebus, ofwbus, simplebus_driver, 0, 0, BUS_PASS_BUS);
EARLY_DRIVER_MODULE(simplebus, simplebus, simplebus_driver, 0, 0,
    BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);

static int
simplebus_probe(device_t dev)
{
 
	if (!ofw_bus_status_okay(dev))
		return (ENXIO);
	/*
	 * XXX We should attach only to pure' compatible = "simple-bus"',
	 * without any other compatible string.
	 * For now, filter only know cases:
	 * "syscon", "simple-bus"; is handled by fdt/syscon driver
	 * "simple-mfd", "simple-bus"; is handled by fdt/simple-mfd driver
	 */
	if (ofw_bus_is_compatible(dev, "syscon") ||
	    ofw_bus_is_compatible(dev, "simple-mfd"))
		return (ENXIO);

	/*
	 * FDT data puts a "simple-bus" compatible string on many things that
	 * have children but aren't really buses in our world.  Without a
	 * ranges property we will fail to attach, so just fail to probe too.
	 */
	if (!(ofw_bus_is_compatible(dev, "simple-bus") &&
	    ofw_bus_has_prop(dev, "ranges")) &&
	    (ofw_bus_get_type(dev) == NULL || strcmp(ofw_bus_get_type(dev),
	     "soc") != 0))
		return (ENXIO);

	device_set_desc(dev, "Flattened device tree simple bus");

	return (BUS_PROBE_GENERIC);
}

int
simplebus_attach_impl(device_t dev)
{
	struct		simplebus_softc *sc;
	phandle_t	node;

	sc = device_get_softc(dev);
	simplebus_init(dev, 0);
	if ((sc->flags & SB_FLAG_NO_RANGES) == 0 &&
	    simplebus_fill_ranges(sc->node, sc) < 0) {
		device_printf(dev, "could not get ranges\n");
		return (ENXIO);
	}

	/*
	 * In principle, simplebus could have an interrupt map, but ignore that
	 * for now
	 */

	for (node = OF_child(sc->node); node > 0; node = OF_peer(node))
		simplebus_add_device(dev, node, 0, NULL, -1, NULL);

	return (0);
}

int
simplebus_attach(device_t dev)
{
	int	rv;

	rv = simplebus_attach_impl(dev);
	if (rv != 0)
		return (rv);

	return (bus_generic_attach(dev));
}

int
simplebus_detach(device_t dev)
{
	struct		simplebus_softc *sc;

	sc = device_get_softc(dev);
	if (sc->ranges != NULL)
		free(sc->ranges, M_DEVBUF);

	return (bus_generic_detach(dev));
}

void
simplebus_init(device_t dev, phandle_t node)
{
	struct simplebus_softc *sc;

	sc = device_get_softc(dev);
	if (node == 0)
		node = ofw_bus_get_node(dev);
	sc->dev = dev;
	sc->node = node;

	/*
	 * Some important numbers
	 */
	sc->acells = 2;
	OF_getencprop(node, "#address-cells", &sc->acells, sizeof(sc->acells));
	sc->scells = 1;
	OF_getencprop(node, "#size-cells", &sc->scells, sizeof(sc->scells));
}

int
simplebus_fill_ranges(phandle_t node, struct simplebus_softc *sc)
{
	int host_address_cells;
	cell_t *base_ranges;
	ssize_t nbase_ranges;
	int err;
	int i, j, k;

	err = OF_searchencprop(OF_parent(node), "#address-cells",
	    &host_address_cells, sizeof(host_address_cells));
	if (err <= 0)
		return (-1);

	nbase_ranges = OF_getproplen(node, "ranges");
	if (nbase_ranges < 0)
		return (-1);
	sc->nranges = nbase_ranges / sizeof(cell_t) /
	    (sc->acells + host_address_cells + sc->scells);
	if (sc->nranges == 0)
		return (0);

	sc->ranges = malloc(sc->nranges * sizeof(sc->ranges[0]),
	    M_DEVBUF, M_WAITOK);
	base_ranges = malloc(nbase_ranges, M_DEVBUF, M_WAITOK);
	OF_getencprop(node, "ranges", base_ranges, nbase_ranges);

	for (i = 0, j = 0; i < sc->nranges; i++) {
		sc->ranges[i].bus = 0;
		for (k = 0; k < sc->acells; k++) {
			sc->ranges[i].bus <<= 32;
			sc->ranges[i].bus |= base_ranges[j++];
		}
		sc->ranges[i].host = 0;
		for (k = 0; k < host_address_cells; k++) {
			sc->ranges[i].host <<= 32;
			sc->ranges[i].host |= base_ranges[j++];
		}
		sc->ranges[i].size = 0;
		for (k = 0; k < sc->scells; k++) {
			sc->ranges[i].size <<= 32;
			sc->ranges[i].size |= base_ranges[j++];
		}
	}

	free(base_ranges, M_DEVBUF);
	return (sc->nranges);
}

struct simplebus_devinfo *
simplebus_setup_dinfo(device_t dev, phandle_t node,
    struct simplebus_devinfo *di)
{
	struct simplebus_softc *sc;
	struct simplebus_devinfo *ndi;

	sc = device_get_softc(dev);
	if (di == NULL)
		ndi = malloc(sizeof(*ndi), M_DEVBUF, M_WAITOK | M_ZERO);
	else
		ndi = di;
	if (ofw_bus_gen_setup_devinfo(&ndi->obdinfo, node) != 0) {
		if (di == NULL)
			free(ndi, M_DEVBUF);
		return (NULL);
	}

	resource_list_init(&ndi->rl);
	ofw_bus_reg_to_rl(dev, node, sc->acells, sc->scells, &ndi->rl);
	ofw_bus_intr_to_rl(dev, node, &ndi->rl, NULL);

	return (ndi);
}

device_t
simplebus_add_device(device_t dev, phandle_t node, u_int order,
    const char *name, int unit, struct simplebus_devinfo *di)
{
	struct simplebus_devinfo *ndi;
	device_t cdev;

	if ((ndi = simplebus_setup_dinfo(dev, node, di)) == NULL)
		return (NULL);
	cdev = device_add_child_ordered(dev, order, name, unit);
	if (cdev == NULL) {
		device_printf(dev, "<%s>: device_add_child failed\n",
		    ndi->obdinfo.obd_name);
		resource_list_free(&ndi->rl);
		ofw_bus_gen_destroy_devinfo(&ndi->obdinfo);
		if (di == NULL)
			free(ndi, M_DEVBUF);
		return (NULL);
	}
	device_set_ivars(cdev, ndi);

	return(cdev);
}

static device_t
simplebus_add_child(device_t dev, u_int order, const char *name, int unit)
{
	device_t cdev;
	struct simplebus_devinfo *ndi;

	cdev = device_add_child_ordered(dev, order, name, unit);
	if (cdev == NULL)
		return (NULL);

	ndi = malloc(sizeof(*ndi), M_DEVBUF, M_WAITOK | M_ZERO);
	ndi->obdinfo.obd_node = -1;
	resource_list_init(&ndi->rl);
	device_set_ivars(cdev, ndi);

	return (cdev);
}

static const struct ofw_bus_devinfo *
simplebus_get_devinfo(device_t bus __unused, device_t child)
{
        struct simplebus_devinfo *ndi;
        
        ndi = device_get_ivars(child);
	if (ndi == NULL)
		return (NULL);
        return (&ndi->obdinfo);
}

static struct resource_list *
simplebus_get_resource_list(device_t bus __unused, device_t child)
{
	struct simplebus_devinfo *ndi;

	ndi = device_get_ivars(child);
	if (ndi == NULL)
		return (NULL);
	return (&ndi->rl);
}

static ssize_t
simplebus_get_property(device_t bus, device_t child, const char *propname,
    void *propvalue, size_t size, device_property_type_t type)
{
	phandle_t node, xref;
	ssize_t ret, i;
	uint32_t *buffer;
	uint64_t val;

	switch (type) {
	case DEVICE_PROP_ANY:
	case DEVICE_PROP_BUFFER:
	case DEVICE_PROP_UINT32:
	case DEVICE_PROP_UINT64:
	case DEVICE_PROP_HANDLE:
		break;
	default:
		return (-1);
	}

	node = ofw_bus_get_node(child);
	if (propvalue == NULL || size == 0)
		return (OF_getproplen(node, propname));

	/*
	 * Integer values are stored in BE format.
	 * If caller declared that the underlying property type is uint32_t
	 * we need to do the conversion to match host endianness.
	 */
	if (type == DEVICE_PROP_UINT32)
		return (OF_getencprop(node, propname, propvalue, size));

	/*
	 * uint64_t also requires endianness handling.
	 * In FDT every 8 byte value is stored using two uint32_t variables
	 * in BE format. Now, since the upper bits are stored as the first
	 * of the pair, both halves require swapping.
	 */
	 if (type == DEVICE_PROP_UINT64) {
		ret = OF_getencprop(node, propname, propvalue, size);
		if (ret <= 0) {
			return (ret);
		}

		buffer = (uint32_t *)propvalue;

		for (i = 0; i < size / 4; i += 2) {
			val = (uint64_t)buffer[i] << 32 | buffer[i + 1];
			((uint64_t *)buffer)[i / 2] = val;
		}
		return (ret);
	}

	if (type == DEVICE_PROP_HANDLE) {
		if (size < sizeof(node))
			return (-1);
		ret = OF_getencprop(node, propname, &xref, sizeof(xref));
		if (ret <= 0)
			return (ret);

		node = OF_node_from_xref(xref);
		if (propvalue != NULL)
			*(uint32_t *)propvalue = node;
		return (ret);
	}

	return (OF_getprop(node, propname, propvalue, size));
}

static struct resource *
simplebus_alloc_resource(device_t bus, device_t child, int type, int *rid,
    rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
{
	struct simplebus_softc *sc;
	struct simplebus_devinfo *di;
	struct resource_list_entry *rle;
	int j;

	sc = device_get_softc(bus);

	/*
	 * Request for the default allocation with a given rid: use resource
	 * list stored in the local device info.
	 */
	if (RMAN_IS_DEFAULT_RANGE(start, end)) {
		if ((di = device_get_ivars(child)) == NULL)
			return (NULL);

		rle = resource_list_find(&di->rl, type, *rid);
		if (rle == NULL) {
			if (bootverbose)
				device_printf(bus, "no default resources for "
				    "rid = %d, type = %d\n", *rid, type);
			return (NULL);
		}
		start = rle->start;
		end = rle->end;
		count = rle->count;
        }

	if (type == SYS_RES_IOPORT)
		type = SYS_RES_MEMORY;

	if (type == SYS_RES_MEMORY) {
		/* Remap through ranges property */
		for (j = 0; j < sc->nranges; j++) {
			if (start >= sc->ranges[j].bus && end <
			    sc->ranges[j].bus + sc->ranges[j].size) {
				start -= sc->ranges[j].bus;
				start += sc->ranges[j].host;
				end -= sc->ranges[j].bus;
				end += sc->ranges[j].host;
				break;
			}
		}
		if (j == sc->nranges && sc->nranges != 0) {
			if (bootverbose)
				device_printf(bus, "Could not map resource "
				    "%#jx-%#jx\n", start, end);

			return (NULL);
		}
	}

	return (bus_generic_alloc_resource(bus, child, type, rid, start, end,
	    count, flags));
}

static int
simplebus_print_res(struct simplebus_devinfo *di)
{
	int rv;

	if (di == NULL)
		return (0);
	rv = 0;
	rv += resource_list_print_type(&di->rl, "mem", SYS_RES_MEMORY, "%#jx");
	rv += resource_list_print_type(&di->rl, "irq", SYS_RES_IRQ, "%jd");
	return (rv);
}

static void
simplebus_probe_nomatch(device_t bus, device_t child)
{
	const char *name, *type, *compat;

	if (!bootverbose)
		return;

	compat = ofw_bus_get_compat(child);
	if (compat == NULL)
		return;
	name = ofw_bus_get_name(child);
	type = ofw_bus_get_type(child);

	device_printf(bus, "<%s>", name != NULL ? name : "unknown");
	simplebus_print_res(device_get_ivars(child));
	if (!ofw_bus_status_okay(child))
		printf(" disabled");
	if (type)
		printf(" type %s", type);
	printf(" compat %s (no driver attached)\n", compat);
}

static int
simplebus_print_child(device_t bus, device_t child)
{
	int rv;

	rv = bus_print_child_header(bus, child);
	rv += simplebus_print_res(device_get_ivars(child));
	if (!ofw_bus_status_okay(child))
		rv += printf(" disabled");
	rv += bus_print_child_footer(bus, child);
	return (rv);
}