// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * This file does the necessary interface mapping between the bootwrapper
 * device tree operations and the interface provided by shared source
 * files flatdevicetree.[ch].
 *
 * Copyright 2007 David Gibson, IBM Corporation.
 */

#include <stddef.h>
#include <stdio.h>
#include <page.h>
#include <libfdt.h>
#include "ops.h"

#define DEBUG   0
#define BAD_ERROR(err)  (((err) < 0) \
                         && ((err) != -FDT_ERR_NOTFOUND) \
                         && ((err) != -FDT_ERR_EXISTS))

#define check_err(err) \
        ({ \
                if (BAD_ERROR(err) || ((err < 0) && DEBUG)) \
                        printf("%s():%d  %s\n\r", __func__, __LINE__, \
                               fdt_strerror(err)); \
                if (BAD_ERROR(err)) \
                        exit(); \
                (err < 0) ? -1 : 0; \
        })

#define offset_devp(off)        \
        ({ \
                unsigned long _offset = (off); \
                check_err(_offset) ? NULL : (void *)(_offset+1); \
        })

#define devp_offset_find(devp)  (((unsigned long)(devp))-1)
#define devp_offset(devp)       (devp ? ((unsigned long)(devp))-1 : 0)

static void *fdt;
static void *buf; /* = NULL */

#define EXPAND_GRANULARITY      1024

static void expand_buf(int minexpand)
{
        int size = fdt_totalsize(fdt);
        int rc;

        size = _ALIGN(size + minexpand, EXPAND_GRANULARITY);
        buf = platform_ops.realloc(buf, size);
        if (!buf)
                fatal("Couldn't find %d bytes to expand device tree\n\r", size);
        rc = fdt_open_into(fdt, buf, size);
        if (rc != 0)
                fatal("Couldn't expand fdt into new buffer: %s\n\r",
                      fdt_strerror(rc));

        fdt = buf;
}

static void *fdt_wrapper_finddevice(const char *path)
{
        return offset_devp(fdt_path_offset(fdt, path));
}

static int fdt_wrapper_getprop(const void *devp, const char *name,
                               void *buf, const int buflen)
{
        const void *p;
        int len;

        p = fdt_getprop(fdt, devp_offset(devp), name, &len);
        if (!p)
                return check_err(len);
        memcpy(buf, p, min(len, buflen));
        return len;
}

static int fdt_wrapper_setprop(const void *devp, const char *name,
                               const void *buf, const int len)
{
        int rc;

        rc = fdt_setprop(fdt, devp_offset(devp), name, buf, len);
        if (rc == -FDT_ERR_NOSPACE) {
                expand_buf(len + 16);
                rc = fdt_setprop(fdt, devp_offset(devp), name, buf, len);
        }

        return check_err(rc);
}

static int fdt_wrapper_del_node(const void *devp)
{
        return fdt_del_node(fdt, devp_offset(devp));
}

static void *fdt_wrapper_get_parent(const void *devp)
{
        return offset_devp(fdt_parent_offset(fdt, devp_offset(devp)));
}

static void *fdt_wrapper_create_node(const void *devp, const char *name)
{
        int offset;

        offset = fdt_add_subnode(fdt, devp_offset(devp), name);
        if (offset == -FDT_ERR_NOSPACE) {
                expand_buf(strlen(name) + 16);
                offset = fdt_add_subnode(fdt, devp_offset(devp), name);
        }

        return offset_devp(offset);
}

static void *fdt_wrapper_find_node_by_prop_value(const void *prev,
                                                 const char *name,
                                                 const char *val,
                                                 int len)
{
        int offset = fdt_node_offset_by_prop_value(fdt, devp_offset_find(prev),
                                                   name, val, len);
        return offset_devp(offset);
}

static void *fdt_wrapper_find_node_by_compatible(const void *prev,
                                                 const char *val)
{
        int offset = fdt_node_offset_by_compatible(fdt, devp_offset_find(prev),
                                                   val);
        return offset_devp(offset);
}

static char *fdt_wrapper_get_path(const void *devp, char *buf, int len)
{
        int rc;

        rc = fdt_get_path(fdt, devp_offset(devp), buf, len);
        if (check_err(rc))
                return NULL;
        return buf;
}

static unsigned long fdt_wrapper_finalize(void)
{
        int rc;

        rc = fdt_pack(fdt);
        if (rc != 0)
                fatal("Couldn't pack flat tree: %s\n\r",
                      fdt_strerror(rc));
        return (unsigned long)fdt;
}

void fdt_init(void *blob)
{
        int err;
        int bufsize;

        dt_ops.finddevice = fdt_wrapper_finddevice;
        dt_ops.getprop = fdt_wrapper_getprop;
        dt_ops.setprop = fdt_wrapper_setprop;
        dt_ops.get_parent = fdt_wrapper_get_parent;
        dt_ops.create_node = fdt_wrapper_create_node;
        dt_ops.find_node_by_prop_value = fdt_wrapper_find_node_by_prop_value;
        dt_ops.find_node_by_compatible = fdt_wrapper_find_node_by_compatible;
        dt_ops.del_node = fdt_wrapper_del_node;
        dt_ops.get_path = fdt_wrapper_get_path;
        dt_ops.finalize = fdt_wrapper_finalize;

        /* Make sure the dt blob is the right version and so forth */
        fdt = blob;
        bufsize = fdt_totalsize(fdt) + EXPAND_GRANULARITY;
        buf = malloc(bufsize);
        if(!buf)
                fatal("malloc failed. can't relocate the device tree\n\r");

        err = fdt_open_into(fdt, buf, bufsize);

        if (err != 0)
                fatal("fdt_init(): %s\n\r", fdt_strerror(err));

        fdt = buf;
}