/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2009-2010 The FreeBSD Foundation
 *
 * This software was developed by Semihalf under sponsorship from
 * the FreeBSD Foundation.
 *
 * 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/ctype.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/stdarg.h>
#include <sys/systm.h>

#include <contrib/libfdt/libfdt.h>

#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofwvar.h>
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus_subr.h>

#include "ofw_if.h"

#ifdef DEBUG
#define debugf(fmt, args...) do { printf("%s(): ", __func__);   \
    printf(fmt,##args); } while (0)
#else
#define debugf(fmt, args...)
#endif

#if defined(__arm__)
#if defined(SOC_MV_ARMADAXP) || defined(SOC_MV_ARMADA38X) || \
    defined(SOC_MV_DISCOVERY) || defined(SOC_MV_DOVE) || \
    defined(SOC_MV_FREY) || defined(SOC_MV_KIRKWOOD) || \
    defined(SOC_MV_LOKIPLUS) || defined(SOC_MV_ORION)
#define FDT_MARVELL
#endif
#endif

static int ofw_fdt_init(ofw_t, void *);
static phandle_t ofw_fdt_peer(ofw_t, phandle_t);
static phandle_t ofw_fdt_child(ofw_t, phandle_t);
static phandle_t ofw_fdt_parent(ofw_t, phandle_t);
static phandle_t ofw_fdt_instance_to_package(ofw_t, ihandle_t);
static ssize_t ofw_fdt_getproplen(ofw_t, phandle_t, const char *);
static ssize_t ofw_fdt_getprop(ofw_t, phandle_t, const char *, void *, size_t);
static int ofw_fdt_nextprop(ofw_t, phandle_t, const char *, char *, size_t);
static int ofw_fdt_setprop(ofw_t, phandle_t, const char *, const void *,
    size_t);
static ssize_t ofw_fdt_canon(ofw_t, const char *, char *, size_t);
static phandle_t ofw_fdt_finddevice(ofw_t, const char *);
static ssize_t ofw_fdt_instance_to_path(ofw_t, ihandle_t, char *, size_t);
static ssize_t ofw_fdt_package_to_path(ofw_t, phandle_t, char *, size_t);
static int ofw_fdt_interpret(ofw_t, const char *, int, cell_t *);

static ofw_method_t ofw_fdt_methods[] = {
        OFWMETHOD(ofw_init,                     ofw_fdt_init),
        OFWMETHOD(ofw_peer,                     ofw_fdt_peer),
        OFWMETHOD(ofw_child,                    ofw_fdt_child),
        OFWMETHOD(ofw_parent,                   ofw_fdt_parent),
        OFWMETHOD(ofw_instance_to_package,      ofw_fdt_instance_to_package),
        OFWMETHOD(ofw_getproplen,               ofw_fdt_getproplen),
        OFWMETHOD(ofw_getprop,                  ofw_fdt_getprop),
        OFWMETHOD(ofw_nextprop,                 ofw_fdt_nextprop),
        OFWMETHOD(ofw_setprop,                  ofw_fdt_setprop),
        OFWMETHOD(ofw_canon,                    ofw_fdt_canon),
        OFWMETHOD(ofw_finddevice,               ofw_fdt_finddevice),
        OFWMETHOD(ofw_instance_to_path,         ofw_fdt_instance_to_path),
        OFWMETHOD(ofw_package_to_path,          ofw_fdt_package_to_path),
        OFWMETHOD(ofw_interpret,                ofw_fdt_interpret),
        { 0, 0 }
};

static ofw_def_t ofw_fdt = {
        OFW_FDT,
        ofw_fdt_methods,
        0
};
OFW_DEF(ofw_fdt);

#define FDT_FBSDVER_LEN 16
#define FDT_MODEL_LEN   80
#define FDT_COMPAT_LEN  255
#define FDT_SERIAL_LEN  32

static void *fdtp = NULL;
static char fdt_model[FDT_MODEL_LEN];
static char fdt_compatible[FDT_COMPAT_LEN];
static char fdt_fbsd_version[FDT_FBSDVER_LEN];
static char fdt_serial[FDT_SERIAL_LEN];

static int
sysctl_handle_dtb(SYSCTL_HANDLER_ARGS)
{

        return (sysctl_handle_opaque(oidp, fdtp, fdt_totalsize(fdtp), req));
}

static void
sysctl_register_fdt_oid(void *arg)
{

        /* If there is no FDT registered, skip adding the sysctl */
        if (fdtp == NULL)
                return;

        SYSCTL_ADD_PROC(NULL, SYSCTL_STATIC_CHILDREN(_hw_fdt), OID_AUTO, "dtb",
            CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
            sysctl_handle_dtb, "", "Device Tree Blob");
        if (fdt_model[0] != '\0')
                SYSCTL_ADD_STRING(NULL, SYSCTL_STATIC_CHILDREN(_hw_fdt),
                    OID_AUTO, "model", CTLFLAG_RD, fdt_model,
                    FDT_MODEL_LEN, "System board model");
        if (fdt_compatible[0] != '\0')
                SYSCTL_ADD_STRING(NULL, SYSCTL_STATIC_CHILDREN(_hw_fdt),
                    OID_AUTO, "compatible", CTLFLAG_RD, fdt_compatible,
                    FDT_COMPAT_LEN, "Compatible platforms");
        if (fdt_fbsd_version[0] != '\0')
                SYSCTL_ADD_STRING(NULL, SYSCTL_STATIC_CHILDREN(_hw_fdt),
                    OID_AUTO, "freebsd-version", CTLFLAG_RD, fdt_fbsd_version,
                    FDT_FBSDVER_LEN, "FreeBSD DTS branding version");
        if (fdt_serial[0] != '\0')
                SYSCTL_ADD_STRING(NULL, SYSCTL_STATIC_CHILDREN(_hw_fdt),
                    OID_AUTO, "serial-number", CTLFLAG_RD, fdt_serial,
                    FDT_SERIAL_LEN, "Serial number");
}
SYSINIT(dtb_oid, SI_SUB_KMEM, SI_ORDER_ANY, sysctl_register_fdt_oid, NULL);

static int
ofw_fdt_init(ofw_t ofw, void *data)
{
        phandle_t root;
        ssize_t len;
        int err;
        int i;

        /* Check FDT blob integrity */
        if ((err = fdt_check_header(data)) != 0)
                return (err);

        fdtp = data;
        root = ofw_fdt_finddevice(NULL, "/");
        len = ofw_fdt_getproplen(NULL, root, "model");
        if (len > 0 && len <= FDT_MODEL_LEN) {
                bzero(fdt_model, FDT_MODEL_LEN);
                ofw_fdt_getprop(NULL, root, "model", fdt_model, FDT_MODEL_LEN);
        }
        len = ofw_fdt_getproplen(NULL, root, "compatible");
        if (len > 0 && len <= FDT_COMPAT_LEN) {
                bzero(fdt_compatible, FDT_COMPAT_LEN);
                ofw_fdt_getprop(NULL, root, "compatible", fdt_compatible,
                    FDT_COMPAT_LEN);
                /* Replace the middle '\0' with ' ' */
                for (i = 0; i < len - 1; i++)
                        if (fdt_compatible[i] == '\0')
                                fdt_compatible[i] = ' ';
        }
        len = ofw_fdt_getproplen(NULL, root, "freebsd,dts-version");
        if (len > 0 && len <= FDT_FBSDVER_LEN) {
                bzero(fdt_fbsd_version, FDT_FBSDVER_LEN);
                ofw_fdt_getprop(NULL, root, "freebsd,dts-version",
                  fdt_fbsd_version, FDT_FBSDVER_LEN);
        }
        len = ofw_fdt_getproplen(NULL, root, "serial-number");
        if (len > 0 && len <= FDT_SERIAL_LEN) {
                bzero(fdt_serial, FDT_SERIAL_LEN);
                ofw_fdt_getprop(NULL, root, "serial-number",
                    fdt_serial, FDT_SERIAL_LEN);
                /*
                 * Non-standard property; check for NUL-terminated
                 * printable string.
                 */
                for (i = 0; i < len - 1; i++) {
                        if (!isprint(fdt_serial[i])) {
                                fdt_serial[0] = '\0';
                                break;
                        }
                }
                if (fdt_serial[len - 1] != '\0')
                        fdt_serial[0] = '\0';
        }
        return (0);
}

/*
 * Device tree functions.
 *
 * We use the offset from fdtp to the node as the 'phandle' in OF interface.
 *
 * phandle is a u32 value, therefore we cannot use the pointer to node as
 * phandle in 64 bit. We also do not use the usual fdt offset as phandle,
 * as it can be 0, and the OF interface has special meaning for phandle 0.
 */

static phandle_t
fdt_offset_phandle(int offset)
{
        if (offset < 0)
                return (0);
        return ((phandle_t)offset + fdt_off_dt_struct(fdtp));
}

static int
fdt_phandle_offset(phandle_t p)
{
        int pint = (int)p;
        int dtoff = fdt_off_dt_struct(fdtp);

        if (pint < dtoff)
                return (-1);
        return (pint - dtoff);
}

/* Return the next sibling of this node or 0. */
static phandle_t
ofw_fdt_peer(ofw_t ofw, phandle_t node)
{
        int offset;

        if (node == 0) {
                /* Find root node */
                offset = fdt_path_offset(fdtp, "/");

                return (fdt_offset_phandle(offset));
        }

        offset = fdt_phandle_offset(node);
        if (offset < 0)
                return (0);
        offset = fdt_next_subnode(fdtp, offset);
        return (fdt_offset_phandle(offset));
}

/* Return the first child of this node or 0. */
static phandle_t
ofw_fdt_child(ofw_t ofw, phandle_t node)
{
        int offset;

        offset = fdt_phandle_offset(node);
        if (offset < 0)
                return (0);
        offset = fdt_first_subnode(fdtp, offset);
        return (fdt_offset_phandle(offset));
}

/* Return the parent of this node or 0. */
static phandle_t
ofw_fdt_parent(ofw_t ofw, phandle_t node)
{
        int offset, paroffset;

        offset = fdt_phandle_offset(node);
        if (offset < 0)
                return (0);

        paroffset = fdt_parent_offset(fdtp, offset);
        return (fdt_offset_phandle(paroffset));
}

/* Return the package handle that corresponds to an instance handle. */
static phandle_t
ofw_fdt_instance_to_package(ofw_t ofw, ihandle_t instance)
{

        /* Where real OF uses ihandles in the tree, FDT uses xref phandles */
        return (OF_node_from_xref(instance));
}

/* Get the length of a property of a package. */
static ssize_t
ofw_fdt_getproplen(ofw_t ofw, phandle_t package, const char *propname)
{
        const void *prop;
        int offset, len;

        offset = fdt_phandle_offset(package);
        if (offset < 0)
                return (-1);

        len = -1;
        prop = fdt_getprop(fdtp, offset, propname, &len);

        if (prop == NULL && strcmp(propname, "name") == 0) {
                /* Emulate the 'name' property */
                fdt_get_name(fdtp, offset, &len);
                return (len + 1);
        }

        if (prop == NULL && offset == fdt_path_offset(fdtp, "/chosen")) {
                if (strcmp(propname, "fdtbootcpu") == 0)
                        return (sizeof(cell_t));
                if (strcmp(propname, "fdtmemreserv") == 0)
                        return (sizeof(uint64_t)*2*fdt_num_mem_rsv(fdtp));
        }

        if (prop == NULL)
                return (-1);

        return (len);
}

/* Get the value of a property of a package. */
static ssize_t
ofw_fdt_getprop(ofw_t ofw, phandle_t package, const char *propname, void *buf,
    size_t buflen)
{
        const void *prop;
        const char *name;
        int len, offset;
        uint32_t cpuid;

        offset = fdt_phandle_offset(package);
        if (offset < 0)
                return (-1);

        prop = fdt_getprop(fdtp, offset, propname, &len);

        if (prop == NULL && strcmp(propname, "name") == 0) {
                /* Emulate the 'name' property */
                name = fdt_get_name(fdtp, offset, &len);
                strncpy(buf, name, buflen);
                return (len + 1);
        }

        if (prop == NULL && offset == fdt_path_offset(fdtp, "/chosen")) {
                if (strcmp(propname, "fdtbootcpu") == 0) {
                        cpuid = cpu_to_fdt32(fdt_boot_cpuid_phys(fdtp));
                        len = sizeof(cpuid);
                        prop = &cpuid;
                }
                if (strcmp(propname, "fdtmemreserv") == 0) {
                        prop = (char *)fdtp + fdt_off_mem_rsvmap(fdtp);
                        len = sizeof(uint64_t)*2*fdt_num_mem_rsv(fdtp);
                }
        }

        if (prop == NULL)
                return (-1);

        bcopy(prop, buf, min(len, buflen));

        return (len);
}

/*
 * Get the next property of a package. Return values:
 *  -1: package or previous property does not exist
 *   0: no more properties
 *   1: success
 */
static int
ofw_fdt_nextprop(ofw_t ofw, phandle_t package, const char *previous, char *buf,
    size_t size)
{
        const void *prop;
        const char *name;
        int offset;

        offset = fdt_phandle_offset(package);
        if (offset < 0)
                return (-1);

        if (previous == NULL)
                /* Find the first prop in the node */
                offset = fdt_first_property_offset(fdtp, offset);
        else {
                fdt_for_each_property_offset(offset, fdtp, offset) {
                        prop = fdt_getprop_by_offset(fdtp, offset, &name, NULL);
                        if (prop == NULL)
                                return (-1); /* Internal error */
                        /* Skip until we find 'previous', then bail out */
                        if (strcmp(name, previous) != 0)
                                continue;
                        offset = fdt_next_property_offset(fdtp, offset);
                        break;
                }
        }

        if (offset < 0)
                return (0); /* No properties */

        prop = fdt_getprop_by_offset(fdtp, offset, &name, &offset);
        if (prop == NULL)
                return (-1); /* Internal error */

        strncpy(buf, name, size);

        return (1);
}

/* Set the value of a property of a package. */
static int
ofw_fdt_setprop(ofw_t ofw, phandle_t package, const char *propname,
    const void *buf, size_t len)
{
        int offset;

        offset = fdt_phandle_offset(package);
        if (offset < 0)
                return (-1);

        if (fdt_setprop_inplace(fdtp, offset, propname, buf, len) != 0)
                /* Try to add property, when setting value inplace failed */
                return (fdt_setprop(fdtp, offset, propname, buf, len));

        return (0);
}

/* Convert a device specifier to a fully qualified pathname. */
static ssize_t
ofw_fdt_canon(ofw_t ofw, const char *device, char *buf, size_t len)
{

        return (-1);
}

/* Return a package handle for the specified device. */
static phandle_t
ofw_fdt_finddevice(ofw_t ofw, const char *device)
{
        int offset;

        offset = fdt_path_offset(fdtp, device);
        if (offset < 0)
                return (-1);
        return (fdt_offset_phandle(offset));
}

/* Return the fully qualified pathname corresponding to an instance. */
static ssize_t
ofw_fdt_instance_to_path(ofw_t ofw, ihandle_t instance, char *buf, size_t len)
{
        phandle_t phandle;

        phandle = OF_instance_to_package(instance);
        if (phandle == -1)
                return (-1);

        return (OF_package_to_path(phandle, buf, len));
}

/* Return the fully qualified pathname corresponding to a package. */
static ssize_t
ofw_fdt_package_to_path(ofw_t ofw, phandle_t package, char *buf, size_t len)
{

        return (-1);
}

#if defined(FDT_MARVELL)
static int
ofw_fdt_fixup(ofw_t ofw)
{
        char model[FDT_MODEL_LEN];
        phandle_t root;
        ssize_t len;
        int i;

        if ((root = ofw_fdt_finddevice(ofw, "/")) == -1)
                return (ENODEV);

        if ((len = ofw_fdt_getproplen(ofw, root, "model")) <= 0)
                return (0);

        bzero(model, FDT_MODEL_LEN);
        if (ofw_fdt_getprop(ofw, root, "model", model, FDT_MODEL_LEN) <= 0)
                return (0);

        /*
         * Search fixup table and call handler if appropriate.
         */
        for (i = 0; fdt_fixup_table[i].model != NULL; i++) {
                if (strncmp(model, fdt_fixup_table[i].model,
                    FDT_MODEL_LEN) != 0)
                        /*
                         * Sometimes it's convenient to provide one
                         * fixup entry that refers to many boards.
                         * To handle this case, simply check if model
                         * is compatible parameter
                         */
                        if(!ofw_bus_node_is_compatible(root,
                            fdt_fixup_table[i].model))
                                continue;

                if (fdt_fixup_table[i].handler != NULL)
                        (*fdt_fixup_table[i].handler)(root);
        }

        return (0);
}
#endif

static int
ofw_fdt_interpret(ofw_t ofw, const char *cmd, int nret, cell_t *retvals)
{
#if defined(FDT_MARVELL)
        int rv;

        /*
         * Note: FDT does not have the possibility to 'interpret' commands,
         * but we abuse the interface a bit to use it for doing non-standard
         * operations on the device tree blob.
         *
         * Currently the only supported 'command' is to trigger performing
         * fixups.
         */
        if (strncmp("perform-fixup", cmd, 13) != 0)
                return (0);

        rv = ofw_fdt_fixup(ofw);
        if (nret > 0)
                retvals[0] = rv;

        return (rv);
#else
        return (0);
#endif
}