/*      $OpenBSD: simplebus.c,v 1.3 2023/09/22 01:10:43 jsg Exp $       */

/*
 * Copyright (c) 2016 Patrick Wildt <patrick@blueri.se>
 *
 * 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/kernel.h>
#include <sys/device.h>
#include <sys/malloc.h>

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

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

int simplebus_match(struct device *, void *, void *);
void simplebus_attach(struct device *, struct device *, void *);

void simplebus_attach_node(struct device *, int);
int simplebus_bs_map(bus_space_tag_t, bus_addr_t, bus_size_t,
    int, bus_space_handle_t *);

const struct cfattach simplebus_ca = {
        sizeof(struct simplebus_softc), simplebus_match, simplebus_attach
};

struct cfdriver simplebus_cd = {
        NULL, "simplebus", DV_DULL
};

/*
 * Simplebus is a generic bus with no special casings.
 */
int
simplebus_match(struct device *parent, void *cfdata, void *aux)
{
        struct fdt_attach_args *fa = (struct fdt_attach_args *)aux;

        /* Guard against non-fdt attach on iobus(4). */
        if (strlen(fa->fa_name) > 0)
                return (0);

        if (fa->fa_node == 0)
                return (0);

        if (!OF_is_compatible(fa->fa_node, "simple-bus"))
                return (0);

        return (1);
}

void
simplebus_attach(struct device *parent, struct device *self, void *aux)
{
        struct simplebus_softc *sc = (struct simplebus_softc *)self;
        struct fdt_attach_args *fa = (struct fdt_attach_args *)aux;
        char name[32];
        int node;

        sc->sc_node = fa->fa_node;
        sc->sc_iot = fa->fa_iot;
        sc->sc_dmat = fa->fa_dmat;
        sc->sc_acells = OF_getpropint(sc->sc_node, "#address-cells",
            fa->fa_acells);
        sc->sc_scells = OF_getpropint(sc->sc_node, "#size-cells",
            fa->fa_scells);
        sc->sc_pacells = fa->fa_acells;
        sc->sc_pscells = fa->fa_scells;

        if (OF_getprop(sc->sc_node, "name", name, sizeof(name)) > 0) {
                name[sizeof(name) - 1] = 0;
                printf(": \"%s\"", name);
        }

        printf("\n");

        memcpy(&sc->sc_bus, sc->sc_iot, sizeof(sc->sc_bus));
        sc->sc_bus.bus_private = sc;
        sc->sc_bus._space_map = simplebus_bs_map;

        sc->sc_rangeslen = OF_getproplen(sc->sc_node, "ranges");
        if (sc->sc_rangeslen > 0 && !(sc->sc_rangeslen % sizeof(uint32_t))) {
                sc->sc_ranges = malloc(sc->sc_rangeslen, M_TEMP, M_WAITOK);
                OF_getpropintarray(sc->sc_node, "ranges", sc->sc_ranges,
                    sc->sc_rangeslen);
        }

        /* Scan the whole tree. */
        sc->sc_early = 1;
        for (node = OF_child(sc->sc_node); node; node = OF_peer(node)) 
                simplebus_attach_node(self, node);

        sc->sc_early = 0;
        for (node = OF_child(sc->sc_node); node; node = OF_peer(node)) 
                simplebus_attach_node(self, node);
}

int
simplebus_submatch(struct device *self, void *match, void *aux)
{
        struct simplebus_softc  *sc = (struct simplebus_softc *)self;
        struct cfdata *cf = match;

        if (cf->cf_loc[0] == sc->sc_early)
                return (*cf->cf_attach->ca_match)(self, match, aux);
        return 0;
}

int
simplebus_print(void *aux, const char *pnp)
{
        struct fdt_attach_args *fa = aux;
        char name[32];

        if (!pnp)
                return (QUIET);

        if (OF_getprop(fa->fa_node, "name", name, sizeof(name)) > 0) {
                name[sizeof(name) - 1] = 0;
                printf("\"%s\"", name);
        } else
                printf("node %u", fa->fa_node);

        printf(" at %s", pnp);

        return (UNCONF);
}

/*
 * Look for a driver that wants to be attached to this node.
 */
void
simplebus_attach_node(struct device *self, int node)
{
        struct simplebus_softc  *sc = (struct simplebus_softc *)self;
        struct fdt_attach_args   fa;
        char                     buffer[128];
        int                      i, len, line;
        uint32_t                *cell, *reg;

        if (!OF_getprop(node, "compatible", buffer, sizeof(buffer)))
                return;

        if (OF_getprop(node, "status", buffer, sizeof(buffer)))
                if (!strcmp(buffer, "disabled"))
                        return;

        memset(&fa, 0, sizeof(fa));
        fa.fa_name = "";
        fa.fa_node = node;
        fa.fa_iot = &sc->sc_bus;
        fa.fa_dmat = sc->sc_dmat;
        fa.fa_acells = sc->sc_acells;
        fa.fa_scells = sc->sc_scells;

        len = OF_getproplen(node, "reg");
        line = (sc->sc_acells + sc->sc_scells) * sizeof(uint32_t);
        if (len > 0 && line > 0 && (len % line) == 0) {
                reg = malloc(len, M_TEMP, M_WAITOK);
                OF_getpropintarray(node, "reg", reg, len);

                fa.fa_reg = malloc((len / line) * sizeof(struct fdt_reg),
                    M_DEVBUF, M_WAITOK | M_ZERO);
                fa.fa_nreg = (len / line);

                for (i = 0, cell = reg; i < len / line; i++) {
                        if (sc->sc_acells >= 1)
                                fa.fa_reg[i].addr = cell[0];
                        if (sc->sc_acells == 2) {
                                fa.fa_reg[i].addr <<= 32;
                                fa.fa_reg[i].addr |= cell[1];
                        }
                        cell += sc->sc_acells;
                        if (sc->sc_scells >= 1)
                                fa.fa_reg[i].size = cell[0];
                        if (sc->sc_scells == 2) {
                                fa.fa_reg[i].size <<= 32;
                                fa.fa_reg[i].size |= cell[1];
                        }
                        cell += sc->sc_scells;
                }

                free(reg, M_TEMP, len);
        }

        len = OF_getproplen(node, "interrupts");
        if (len > 0 && (len % sizeof(uint32_t)) == 0) {
                fa.fa_intr = malloc(len, M_DEVBUF, M_WAITOK);
                fa.fa_nintr = len / sizeof(uint32_t);

                OF_getpropintarray(node, "interrupts", fa.fa_intr, len);
        }

        config_found_sm(self, &fa, sc->sc_early ? NULL : simplebus_print,
            simplebus_submatch);

        free(fa.fa_reg, M_DEVBUF, fa.fa_nreg * sizeof(struct fdt_reg));
        free(fa.fa_intr, M_DEVBUF, fa.fa_nintr * sizeof(uint32_t));
}

/*
 * Translate memory address if needed.
 */
int
simplebus_bs_map(bus_space_tag_t t, bus_addr_t bpa, bus_size_t size,
    int flag, bus_space_handle_t *bshp)
{
        struct simplebus_softc *sc = t->bus_private;
        uint64_t addr, rfrom, rto, rsize;
        uint32_t *range;
        int parent, rlen, rone;

        addr = bpa;
        parent = OF_parent(sc->sc_node);
        if (parent == 0)
                return bus_space_map(sc->sc_iot, addr, size, flag, bshp);

        if (sc->sc_rangeslen < 0)
                return EINVAL;
        if (sc->sc_rangeslen == 0)
                return bus_space_map(sc->sc_iot, addr, size, flag, bshp);

        rlen = sc->sc_rangeslen / sizeof(uint32_t);
        rone = sc->sc_pacells + sc->sc_acells + sc->sc_scells;

        /* For each range. */
        for (range = sc->sc_ranges; rlen >= rone; rlen -= rone, range += rone) {
                /* Extract from and size, so we can see if we fit. */
                rfrom = range[0];
                if (sc->sc_acells == 2)
                        rfrom = (rfrom << 32) + range[1];
                rsize = range[sc->sc_acells + sc->sc_pacells];
                if (sc->sc_scells == 2)
                        rsize = (rsize << 32) +
                            range[sc->sc_acells + sc->sc_pacells + 1];

                /* Try next, if we're not in the range. */
                if (addr < rfrom || (addr + size) > (rfrom + rsize))
                        continue;

                /* All good, extract to address and translate. */
                rto = range[sc->sc_acells];
                if (sc->sc_pacells == 2)
                        rto = (rto << 32) + range[sc->sc_acells + 1];

                addr -= rfrom;
                addr += rto;

                return bus_space_map(sc->sc_iot, addr, size, flag, bshp);
        }

        return ESRCH;
}