/* $NetBSD: fdtbus.c,v 1.48 2025/10/04 01:38:02 thorpej Exp $ */

/*-
 * Copyright (c) 2015 Jared D. McNeill <jmcneill@invisible.ca>
 * 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 ``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 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>
__KERNEL_RCSID(0, "$NetBSD: fdtbus.c,v 1.48 2025/10/04 01:38:02 thorpej Exp $");

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

#include <sys/bus.h>

#include <dev/ofw/openfirm.h>

#include <dev/fdt/fdtvar.h>

#include <libfdt.h>

#include "locators.h"

#define FDT_MAX_PATH    256

struct fdt_node {
        device_t        n_bus;
        device_t        n_dev;
        int             n_phandle;
        const char      *n_name;
        struct fdt_attach_args n_faa;

        int             n_cfpass;
        cfdata_t        n_cf;

        u_int           n_order;

        bool            n_pinctrl_init;

        TAILQ_ENTRY(fdt_node) n_nodes;
};

static TAILQ_HEAD(, fdt_node) fdt_nodes =
    TAILQ_HEAD_INITIALIZER(fdt_nodes);
static bool fdt_need_rescan = false;

struct fdt_softc {
        device_t        sc_dev;
        int             sc_phandle;
        struct fdt_attach_args sc_faa;
};

static int      fdt_match(device_t, cfdata_t, void *);
static void     fdt_attach(device_t, device_t, void *);
static int      fdt_rescan(device_t, const char *, const int *);
static void     fdt_childdet(device_t, device_t);

static int      fdt_scan_submatch(device_t, cfdata_t, const int *, void *);
static void     fdt_scan_best(struct fdt_softc *, struct fdt_node *);
static void     fdt_scan(struct fdt_softc *, int);
static void     fdt_add_node(struct fdt_node *);
static u_int    fdt_get_order(int);
static void     fdt_pre_attach(struct fdt_node *);
static void     fdt_post_attach(struct fdt_node *);

static const struct device_compatible_entry compat_data[] = {
        { .compat = "simple-bus" },
        { .compat = "simple-pm-bus" },
        DEVICE_COMPAT_EOL
};

CFATTACH_DECL2_NEW(simplebus, sizeof(struct fdt_softc),
    fdt_match, fdt_attach, NULL, NULL, fdt_rescan, fdt_childdet);

static int
fdt_match(device_t parent, cfdata_t cf, void *aux)
{
        const struct fdt_attach_args *faa = aux;
        const int phandle = faa->faa_phandle;
        int match;

        /* Check compatible string */
        match = of_compatible_match(phandle, compat_data);
        if (match)
                return match;

        /* Some nodes have no compatible string */
        if (!of_hasprop(phandle, "compatible")) {
                if (OF_finddevice("/clocks") == phandle)
                        return 1;
                if (OF_finddevice("/chosen") == phandle)
                        return 1;
        }

        /* Always match the root node */
        return OF_finddevice("/") == phandle;
}

static void
fdt_attach(device_t parent, device_t self, void *aux)
{
        struct fdt_softc *sc = device_private(self);
        const struct fdt_attach_args *faa = aux;
        const int phandle = faa->faa_phandle;
        const char *descr, *model;

        sc->sc_dev = self;
        sc->sc_phandle = phandle;
        sc->sc_faa = *faa;

        aprint_naive("\n");

        descr = fdtbus_get_string(phandle, "model");
        if (descr)
                aprint_normal(": %s\n", descr);
        else
                aprint_normal("\n");

        /* Find all child nodes */
        fdt_add_bus(self, phandle, &sc->sc_faa);

        /* Only the root bus should scan for devices */
        if (OF_finddevice("/") != faa->faa_phandle)
                return;

        /* Set hw.model if available */
        model = fdtbus_get_string(phandle, "compatible");
        if (model)
                cpu_setmodel("%s", model);
        else if (descr)
                cpu_setmodel("%s", descr);

        /* Scan devices */
        fdt_rescan(self, NULL, NULL);
}

static int
fdt_rescan(device_t self, const char *ifattr, const int *locs)
{
        struct fdt_softc *sc = device_private(self);
        struct fdt_node *node;
        int pass;

        TAILQ_FOREACH(node, &fdt_nodes, n_nodes)
                fdt_scan_best(sc, node);

        pass = 0;
        fdt_need_rescan = false;
        do {
                fdt_scan(sc, pass);
                if (fdt_need_rescan == true) {
                        pass = 0;
                        TAILQ_FOREACH(node, &fdt_nodes, n_nodes) {
                                if (node->n_cfpass == -1)
                                        fdt_scan_best(sc, node);
                        }
                        fdt_need_rescan = false;
                } else {
                        pass++;
                }
        } while (pass <= FDTCF_PASS_DEFAULT);

        return 0;
}

static void
fdt_childdet(device_t parent, device_t child)
{
        struct fdt_node *node;

        TAILQ_FOREACH(node, &fdt_nodes, n_nodes)
                if (node->n_dev == child) {
                        node->n_dev = NULL;
                        break;
                }
}

static void
fdt_init_attach_args(const struct fdt_attach_args *faa_tmpl, struct fdt_node *node,
    bool quiet, struct fdt_attach_args *faa)
{
        *faa = *faa_tmpl;
        faa->faa_phandle = node->n_phandle;
        faa->faa_name = node->n_name;
        faa->faa_quiet = quiet;
        faa->faa_bst = node->n_faa.faa_bst;
        faa->faa_dmat = fdtbus_iommu_map(node->n_phandle, 0,
           node->n_faa.faa_dmat);
}

static bool
fdt_add_bus_stdmatch(void *arg, int child)
{
        return fdtbus_status_okay(child);
}

void
fdt_add_bus(device_t bus, const int phandle, struct fdt_attach_args *faa)
{
        fdt_add_bus_match(bus, phandle, faa, fdt_add_bus_stdmatch, NULL);
}

void
fdt_add_bus_match(device_t bus, const int phandle, struct fdt_attach_args *faa,
    bool (*fn)(void *, int), void *fnarg)
{
        int child;

        for (child = OF_child(phandle); child; child = OF_peer(child)) {
                if (fn && !fn(fnarg, child))
                        continue;

                fdt_add_child(bus, child, faa, fdt_get_order(child));
        }
}

static int
fdt_dma_translate(int phandle, struct fdt_dma_range **ranges, u_int *nranges)
{
        const uint8_t *data;
        int len, n;

        const int parent = OF_parent(phandle);
        if (parent == -1)
                return 1;       /* done searching */

        data = fdtbus_get_prop(phandle, "dma-ranges", &len);
        if (data == NULL)
                return 1;       /* no dma-ranges property, stop searching */

        if (len == 0)
                return 0;       /* dma-ranges property is empty, keep going */

        const int addr_cells = fdtbus_get_addr_cells(phandle);
        const int size_cells = fdtbus_get_size_cells(phandle);
        const int paddr_cells = fdtbus_get_addr_cells(parent);
        if (addr_cells == -1 || size_cells == -1 || paddr_cells == -1)
                return 1;

        const int entry_size = (addr_cells + paddr_cells + size_cells) * 4;

        *nranges = len / entry_size;
        *ranges = kmem_alloc(sizeof(struct fdt_dma_range) * *nranges, KM_SLEEP);
        for (n = 0; len >= entry_size; n++, len -= entry_size) {
                const uint64_t cba = fdtbus_get_cells(data, addr_cells);
                data += addr_cells * 4;
                const uint64_t pba = fdtbus_get_cells(data, paddr_cells);
                data += paddr_cells * 4;
                const uint64_t cl = fdtbus_get_cells(data, size_cells);
                data += size_cells * 4;

                (*ranges)[n].dr_sysbase = pba;
                (*ranges)[n].dr_busbase = cba;
                (*ranges)[n].dr_len = cl;
        }

        return 1;
}

static bus_dma_tag_t
fdt_get_dma_tag(struct fdt_node *node)
{
        struct fdt_dma_range *ranges = NULL;
        u_int nranges = 0;
        int parent;

        parent = OF_parent(node->n_phandle);
        while (parent != -1) {
                if (fdt_dma_translate(parent, &ranges, &nranges) != 0)
                        break;
                parent = OF_parent(parent);
        }

        return fdtbus_dma_tag_create(node->n_phandle, ranges, nranges);
}

static uint32_t
fdt_bus_flags(int phandle, uint32_t *flags)
{
        if (of_hasprop(phandle, "nonposted-mmio")) {
                *flags |= FDT_BUS_SPACE_FLAG_NONPOSTED_MMIO;
                return 1;
        }

        return 0;
}

static bus_space_tag_t
fdt_get_bus_tag(struct fdt_node *node)
{
        uint32_t flags = 0;
        int parent;

        parent = OF_parent(node->n_phandle);
        while (parent != -1) {
                if (fdt_bus_flags(parent, &flags) != 0) {
                        break;
                }
                parent = OF_parent(parent);
        }

        return fdtbus_bus_tag_create(node->n_phandle, flags);
}

void
fdt_add_child(device_t bus, const int child, struct fdt_attach_args *faa,
    u_int order)
{
        struct fdt_node *node;

        /* Add the node to our device list */
        node = kmem_zalloc(sizeof(*node), KM_SLEEP);
        node->n_bus = bus;
        node->n_dev = NULL;
        node->n_phandle = child;
        node->n_name = fdtbus_get_string(child, "name");
        node->n_cfpass = -1;
        node->n_cf = NULL;
        node->n_order = order;
        if (faa != NULL) {
                node->n_faa = *faa;
        } else {
                memset(&node->n_faa, 0, sizeof(node->n_faa));
        }
        node->n_faa.faa_phandle = child;
        node->n_faa.faa_name = node->n_name;
        node->n_faa.faa_bst = fdt_get_bus_tag(node);
        node->n_faa.faa_dmat = fdt_get_dma_tag(node);

        fdt_add_node(node);
        fdt_need_rescan = true;
}

static int
fdt_scan_submatch(device_t parent, cfdata_t cf, const int *locs, void *aux)
{
        if (locs[FDTCF_PASS] != FDTCF_PASS_DEFAULT &&
            locs[FDTCF_PASS] != cf->cf_loc[FDTCF_PASS])
                return 0;

        return config_stdsubmatch(parent, cf, locs, aux);
}

static void
fdt_scan_best(struct fdt_softc *sc, struct fdt_node *node)
{
        struct fdt_attach_args faa;
        cfdata_t cf, best_cf;
        int match, best_match, best_pass;

        best_cf = NULL;
        best_match = 0;
        best_pass = FDTCF_PASS_DEFAULT;

        for (int pass = 0; pass <= FDTCF_PASS_DEFAULT; pass++) {
                const int locs[FDTCF_NLOCS] = {
                        [FDTCF_PASS] = pass
                };
                fdt_init_attach_args(&sc->sc_faa, node, true, &faa);
                cf = config_search(node->n_bus, &faa,
                    CFARGS(.submatch = fdt_scan_submatch,
                           .iattr = "fdt",
                           .locators = locs));
                if (cf == NULL)
                        continue;
                match = config_match(node->n_bus, cf, &faa);
                if (match > best_match) {
                        best_match = match;
                        best_cf = cf;
                        best_pass = pass;
                }
        }

        node->n_cf = best_cf;
        node->n_cfpass = best_pass;
}

static void
fdt_scan(struct fdt_softc *sc, int pass)
{
        struct fdt_node *node;
        struct fdt_attach_args faa;
        const int locs[FDTCF_NLOCS] = {
                [FDTCF_PASS] = pass
        };
        bool quiet = pass != FDTCF_PASS_DEFAULT;

        TAILQ_FOREACH(node, &fdt_nodes, n_nodes) {
                if (node->n_cfpass != pass || node->n_dev != NULL)
                        continue;

                fdt_init_attach_args(&sc->sc_faa, node, quiet, &faa);

                if (quiet && node->n_cf == NULL) {
                        /*
                         * No match for this device, skip it.
                         */
                        continue;
                }

                /*
                 * Attach the device.
                 */
                fdt_pre_attach(node);

                devhandle_t nodeh = device_handle(node->n_bus);

                if (quiet) {
                        node->n_dev = config_attach(node->n_bus, node->n_cf,
                            &faa, fdtbus_print,
                            CFARGS(.locators = locs,
                                   .devhandle =
                                       devhandle_from_of(nodeh,
                                                         node->n_phandle)));
                } else {
                        /*
                         * Default pass.
                         */
                        node->n_dev = config_found(node->n_bus, &faa,
                            fdtbus_print,
                            CFARGS(.submatch = fdt_scan_submatch,
                                   .iattr = "fdt",
                                   .locators = locs,
                                   .devhandle =
                                       devhandle_from_of(nodeh,
                                                         node->n_phandle)));
                }

                if (node->n_dev != NULL)
                        fdt_post_attach(node);
        }
}

static void
fdt_pre_attach(struct fdt_node *node)
{
        const char *cfgname;
        int error;

        node->n_pinctrl_init = fdtbus_pinctrl_has_config(node->n_phandle, "init");

        cfgname = node->n_pinctrl_init ? "init" : "default";

        aprint_debug_dev(node->n_bus, "set %s config for %s\n", cfgname, node->n_name);

        error = fdtbus_pinctrl_set_config(node->n_phandle, cfgname);
        if (error != 0 && error != ENOENT)
                aprint_debug_dev(node->n_bus,
                    "failed to set %s config on %s: %d\n",
                    cfgname, node->n_name, error);

        fdtbus_powerdomain_enable(node->n_phandle);
}

static void
fdt_post_attach(struct fdt_node *node)
{
        int error;

        if (node->n_pinctrl_init) {
                aprint_debug_dev(node->n_bus, "set default config for %s\n", node->n_name);
                error = fdtbus_pinctrl_set_config(node->n_phandle, "default");
                if (error != 0 && error != ENOENT)
                        aprint_debug_dev(node->n_bus,
                            "failed to set default config on %s: %d\n",
                            node->n_name, error);
        }
}

static void
fdt_add_node(struct fdt_node *new_node)
{
        struct fdt_node *node;

        TAILQ_FOREACH(node, &fdt_nodes, n_nodes)
                if (node->n_order > new_node->n_order) {
                        TAILQ_INSERT_BEFORE(node, new_node, n_nodes);
                        return;
                }
        TAILQ_INSERT_TAIL(&fdt_nodes, new_node, n_nodes);
}

void
fdt_remove_byhandle(int phandle)
{
        struct fdt_node *node;

        TAILQ_FOREACH(node, &fdt_nodes, n_nodes) {
                if (node->n_phandle == phandle) {
                        TAILQ_REMOVE(&fdt_nodes, node, n_nodes);
                        return;
                }
        }
}

void
fdt_remove_bycompat(const char *compatible[])
{
        struct fdt_node *node, *next;

        TAILQ_FOREACH_SAFE(node, &fdt_nodes, n_nodes, next) {
                if (of_compatible(node->n_phandle, compatible)) {
                        TAILQ_REMOVE(&fdt_nodes, node, n_nodes);
                }
        }
}

int
fdt_find_with_property(const char *prop, int *pindex)
{
        struct fdt_node *node;
        int index = 0;

        TAILQ_FOREACH(node, &fdt_nodes, n_nodes) {
                if (index++ < *pindex)
                        continue;
                if (of_hasprop(node->n_phandle, prop)) {
                        *pindex = index;
                        return node->n_phandle;
                }
        }

        return -1;
}

static u_int
fdt_get_order(int phandle)
{
        u_int val = UINT_MAX;
        int child;

        of_getprop_uint32(phandle, "phandle", &val);

        for (child = OF_child(phandle); child; child = OF_peer(child)) {
                u_int child_val = fdt_get_order(child);
                if (child_val < val)
                        val = child_val;
        }

        return val;
}

int
fdtbus_print(void *aux, const char *pnp)
{
        const struct fdt_attach_args * const faa = aux;
        char buf[FDT_MAX_PATH];
        const char *name = buf;
        int len;

        if (pnp && faa->faa_quiet)
                return QUIET;

        /* Skip "not configured" for nodes w/o compatible property */
        if (pnp && OF_getproplen(faa->faa_phandle, "compatible") <= 0)
                return QUIET;

        if (!fdtbus_get_path(faa->faa_phandle, buf, sizeof(buf)))
                name = faa->faa_name;

        if (pnp) {
                aprint_normal("%s at %s", name, pnp);
                const char *compat = fdt_getprop(fdtbus_get_data(),
                    fdtbus_phandle2offset(faa->faa_phandle), "compatible",
                    &len);
                while (len > 0) {
                        aprint_debug(" <%s>", compat);
                        len -= (strlen(compat) + 1);
                        compat += (strlen(compat) + 1);
                }
        } else
                aprint_debug(" (%s)", name);

        return UNCONF;
}