/*-
 * 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>

#include "pci_if.h"
#include "pcib_if.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);

/*
 * PCI interface for MSI interrupts
 */
static pci_get_id_t simplebus_get_id;
static pci_alloc_msi_t simplebus_alloc_msi;

/*
 * PCIB interface
 */
static pcib_alloc_msi_t simplebus_pcib_alloc_msi;
static pcib_release_msi_t simplebus_pcib_release_msi;
static pcib_alloc_msix_t simplebus_pcib_alloc_msix;
static pcib_release_msix_t simplebus_pcib_release_msix;
static pcib_map_msi_t simplebus_pcib_map_msi;

/*
 * 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),

        /* PCI interface for MSI interrupts */
        DEVMETHOD(pci_get_id,           simplebus_get_id),
        DEVMETHOD(pci_alloc_msi,        simplebus_alloc_msi),

        /* PCIB interface */
        DEVMETHOD(pcib_alloc_msi,       simplebus_pcib_alloc_msi),
        DEVMETHOD(pcib_release_msi,     simplebus_pcib_release_msi),
        DEVMETHOD(pcib_alloc_msix,      simplebus_pcib_alloc_msix),
        DEVMETHOD(pcib_release_msix,    simplebus_pcib_release_msix),
        DEVMETHOD(pcib_map_msi,         simplebus_pcib_map_msi),

        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);

        bus_attach_children(dev);
        return (0);
}

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

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

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

        return (0);
}

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_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);
}

static int
simplebus_get_id(device_t dev, device_t child, enum pci_id_type type,
    uintptr_t *id)
{
        phandle_t node, xref;
        pcell_t *cells;
        uintptr_t rid;
        int error, ncells;

        if (type != PCI_ID_MSI)
                return (EINVAL);

        node = ofw_bus_get_node(child);
        error = ofw_bus_parse_xref_list_alloc(node, "msi-parent", "#msi-cells",
            0, &xref, &ncells, &cells);
        if (error != 0)
                return (error);

        rid = 0;
        if (ncells > 0)
                rid = cells[0];

        *id = rid;
        return (0);
}

static int
simplebus_alloc_msi(device_t bus, device_t child, int *count)
{
        struct simplebus_devinfo *ndi;
        struct resource_list_entry *rle;
        int error, i, irq_count, *irqs;

        if (*count < 1)
                return (EINVAL);

        ndi = device_get_ivars(child);
        if (ndi == NULL)
                return (ENXIO);

        /* Only MSI or non-MSI for now */
        rle = resource_list_find(&ndi->rl, SYS_RES_IRQ, 0);
        if (rle != NULL && rle->res != NULL)
                return (ENXIO);

        irq_count = *count;
        irqs = mallocarray(irq_count, sizeof(int), M_DEVBUF, M_WAITOK | M_ZERO);

        error = PCIB_ALLOC_MSI(bus, child, irq_count, irq_count, irqs);
        if (error != 0)
                goto out;

        for (i = 0; i < irq_count; i++) {
                error = bus_generic_rl_set_resource(bus, child, SYS_RES_IRQ,
                    i + 1, irqs[i], 1);
                if (error != 0)
                        break;
        }

        /* Clean up resources if something failed */
        if (error != 0) {
                for (int j = 0; j < i; j++) {
                        bus_generic_rl_delete_resource(bus, child, SYS_RES_IRQ,
                            j + 1);
                }
        }
out:
        free(irqs, M_DEVBUF);
        return (error);
}

static int
simplebus_pcib_alloc_msi(device_t dev, device_t child, int count, int maxcount,
    int *irqs)
{
        return (PCIB_ALLOC_MSI(device_get_parent(dev), child, count, maxcount,
            irqs));
}

static int
simplebus_pcib_release_msi(device_t dev, device_t child, int count, int *irqs)
{
        return (PCIB_RELEASE_MSI(device_get_parent(dev), child, count, irqs));
}

static int
simplebus_pcib_alloc_msix(device_t dev, device_t child, int *irq)
{
        return (PCIB_ALLOC_MSIX(device_get_parent(dev), child, irq));
}

static int
simplebus_pcib_release_msix(device_t dev, device_t child, int irq)
{
        return (PCIB_RELEASE_MSIX(device_get_parent(dev), child, irq));
}

static int
simplebus_pcib_map_msi(device_t dev, device_t child, int irq, uint64_t *addr,
    uint32_t *data)
{
        return (PCIB_MAP_MSI(device_get_parent(dev), child, irq, addr,
            data));
}