fdt_ro.c

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/*
 * libfdt - Flat Device Tree manipulation
 * Copyright (C) 2006 David Gibson, IBM Corporation.
 *
 * libfdt is dual licensed: you can use it either under the terms of
 * the GPL, or the BSD license, at your option.
 *
 *  a) This library is free software; you can redistribute it and/or
 *     modify it under the terms of the GNU General Public License as
 *     published by the Free Software Foundation; either version 2 of the
 *     License, or (at your option) any later version.
 *
 *     This library is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public
 *     License along with this library; if not, write to the Free
 *     Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
 *     MA 02110-1301 USA
 *
 * Alternatively,
 *
 *  b) 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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 "libfdt_env.h"

#include <fdt.h>
#include <libfdt.h>

#include "libfdt_internal.h"

static int _fdt_nodename_eq(const void *fdt, int offset,
                const char *s, int len)
{
    const char *p = fdt_offset_ptr(fdt, offset + FDT_TAGSIZE, len+1);

    if (! p)
        /* short match */
        return 0;

    if (memcmp(p, s, len) != 0)
        return 0;

    if (p[len] == '\0')
        return 1;
    else if (!memchr(s, '@', len) && (p[len] == '@'))
        return 1;
    else
        return 0;
}

const char *fdt_string(const void *fdt, int stroffset)
{
    return (const char *)fdt + fdt_off_dt_strings(fdt) + stroffset;
}

static int _fdt_string_eq(const void *fdt, int stroffset,
              const char *s, int len)
{
    const char *p = fdt_string(fdt, stroffset);

    return (strlen(p) == len) && (memcmp(p, s, len) == 0);
}

int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size)
{
    FDT_CHECK_HEADER(fdt);
    *address = fdt64_to_cpu(_fdt_mem_rsv(fdt, n)->address);
    *size = fdt64_to_cpu(_fdt_mem_rsv(fdt, n)->size);
    return 0;
}

int fdt_num_mem_rsv(const void *fdt)
{
    int i = 0;

    while (fdt64_to_cpu(_fdt_mem_rsv(fdt, i)->size) != 0)
        i++;
    return i;
}

static int _nextprop(const void *fdt, int offset)
{
    uint32_t tag;
    int nextoffset;

    do {
        tag = fdt_next_tag(fdt, offset, &nextoffset);

        switch (tag) {
        case FDT_END:
            if (nextoffset >= 0)
                return -FDT_ERR_BADSTRUCTURE;
            else
                return nextoffset;

        case FDT_PROP:
            return offset;
        }
        offset = nextoffset;
    } while (tag == FDT_NOP);

    return -FDT_ERR_NOTFOUND;
}

int fdt_subnode_offset_namelen(const void *fdt, int offset,
                   const char *name, int namelen)
{
    int depth;

    FDT_CHECK_HEADER(fdt);

    for (depth = 0;
         (offset >= 0) && (depth >= 0);
         offset = fdt_next_node(fdt, offset, &depth))
        if ((depth == 1)
            && _fdt_nodename_eq(fdt, offset, name, namelen))
            return offset;

    if (depth < 0)
        return -FDT_ERR_NOTFOUND;
    return offset; /* error */
}

int fdt_subnode_offset(const void *fdt, int parentoffset,
               const char *name)
{
    return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name));
}

int fdt_path_offset(const void *fdt, const char *path)
{
    const char *end = path + strlen(path);
    const char *p = path;
    int offset = 0;

    FDT_CHECK_HEADER(fdt);

    /* see if we have an alias */
    if (*path != '/') {
        const char *q = strchr(path, '/');

        if (!q)
            q = end;

        p = fdt_get_alias_namelen(fdt, p, q - p);
        if (!p)
            return -FDT_ERR_BADPATH;
        offset = fdt_path_offset(fdt, p);

        p = q;
    }

    while (*p) {
        const char *q;

        while (*p == '/')
            p++;
        if (! *p)
            return offset;
        q = strchr(p, '/');
        if (! q)
            q = end;

        offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);
        if (offset < 0)
            return offset;

        p = q;
    }

    return offset;
}

const char *fdt_get_name(const void *fdt, int nodeoffset, int *len)
{
    const struct fdt_node_header *nh = _fdt_offset_ptr(fdt, nodeoffset);
    int err;

    if (((err = fdt_check_header(fdt)) != 0)
        || ((err = _fdt_check_node_offset(fdt, nodeoffset)) < 0))
            goto fail;

    if (len)
        *len = strlen(nh->name);

    return nh->name;

 fail:
    if (len)
        *len = err;
    return NULL;
}

int fdt_first_property_offset(const void *fdt, int nodeoffset)
{
    int offset;

    if ((offset = _fdt_check_node_offset(fdt, nodeoffset)) < 0)
        return offset;

    return _nextprop(fdt, offset);
}

int fdt_next_property_offset(const void *fdt, int offset)
{
    if ((offset = _fdt_check_prop_offset(fdt, offset)) < 0)
        return offset;

    return _nextprop(fdt, offset);
}

const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
                              int offset,
                              int *lenp)
{
    int err;
    const struct fdt_property *prop;

    if ((err = _fdt_check_prop_offset(fdt, offset)) < 0) {
        if (lenp)
            *lenp = err;
        return NULL;
    }

    prop = _fdt_offset_ptr(fdt, offset);

    if (lenp)
        *lenp = fdt32_to_cpu(prop->len);

    return prop;
}

const struct fdt_property *fdt_get_property_namelen(const void *fdt,
                            int offset,
                            const char *name,
                            int namelen, int *lenp)
{
    for (offset = fdt_first_property_offset(fdt, offset);
         (offset >= 0);
         (offset = fdt_next_property_offset(fdt, offset))) {
        const struct fdt_property *prop;

        if (!(prop = fdt_get_property_by_offset(fdt, offset, lenp))) {
            offset = -FDT_ERR_INTERNAL;
            break;
        }
        if (_fdt_string_eq(fdt, fdt32_to_cpu(prop->nameoff),
                   name, namelen))
            return prop;
    }

    if (lenp)
        *lenp = offset;
    return NULL;
}

const struct fdt_property *fdt_get_property(const void *fdt,
                        int nodeoffset,
                        const char *name, int *lenp)
{
    return fdt_get_property_namelen(fdt, nodeoffset, name,
                    strlen(name), lenp);
}

const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
                const char *name, int namelen, int *lenp)
{
    const struct fdt_property *prop;

    prop = fdt_get_property_namelen(fdt, nodeoffset, name, namelen, lenp);
    if (! prop)
        return NULL;

    return prop->data;
}

const void *fdt_getprop_by_offset(const void *fdt, int offset,
                  const char **namep, int *lenp)
{
    const struct fdt_property *prop;

    prop = fdt_get_property_by_offset(fdt, offset, lenp);
    if (!prop)
        return NULL;
    if (namep)
        *namep = fdt_string(fdt, fdt32_to_cpu(prop->nameoff));
    return prop->data;
}

const void *fdt_getprop(const void *fdt, int nodeoffset,
            const char *name, int *lenp)
{
    return fdt_getprop_namelen(fdt, nodeoffset, name, strlen(name), lenp);
}

uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
{
    const uint32_t *php;
    int len;

    /* FIXME: This is a bit sub-optimal, since we potentially scan
     * over all the properties twice. */
    php = fdt_getprop(fdt, nodeoffset, "phandle", &len);
    if (!php || (len != sizeof(*php))) {
        php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len);
        if (!php || (len != sizeof(*php)))
            return 0;
    }

    return fdt32_to_cpu(*php);
}

const char *fdt_get_alias_namelen(const void *fdt,
                  const char *name, int namelen)
{
    int aliasoffset;

    aliasoffset = fdt_path_offset(fdt, "/aliases");
    if (aliasoffset < 0)
        return NULL;

    return fdt_getprop_namelen(fdt, aliasoffset, name, namelen, NULL);
}

const char *fdt_get_alias(const void *fdt, const char *name)
{
    return fdt_get_alias_namelen(fdt, name, strlen(name));
}

int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen)
{
    int pdepth = 0, p = 0;
    int offset, depth, namelen;
    const char *name;

    FDT_CHECK_HEADER(fdt);

    if (buflen < 2)
        return -FDT_ERR_NOSPACE;

    for (offset = 0, depth = 0;
         (offset >= 0) && (offset <= nodeoffset);
         offset = fdt_next_node(fdt, offset, &depth)) {
        while (pdepth > depth) {
            do {
                p--;
            } while (buf[p-1] != '/');
            pdepth--;
        }

        if (pdepth >= depth) {
            name = fdt_get_name(fdt, offset, &namelen);
            if (!name)
                return namelen;
            if ((p + namelen + 1) <= buflen) {
                memcpy(buf + p, name, namelen);
                p += namelen;
                buf[p++] = '/';
                pdepth++;
            }
        }

        if (offset == nodeoffset) {
            if (pdepth < (depth + 1))
                return -FDT_ERR_NOSPACE;

            if (p > 1) /* special case so that root path is "/", not "" */
                p--;
            buf[p] = '\0';
            return 0;
        }
    }

    if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
        return -FDT_ERR_BADOFFSET;
    else if (offset == -FDT_ERR_BADOFFSET)
        return -FDT_ERR_BADSTRUCTURE;

    return offset; /* error from fdt_next_node() */
}

int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
                 int supernodedepth, int *nodedepth)
{
    int offset, depth;
    int supernodeoffset = -FDT_ERR_INTERNAL;

    FDT_CHECK_HEADER(fdt);

    if (supernodedepth < 0)
        return -FDT_ERR_NOTFOUND;

    for (offset = 0, depth = 0;
         (offset >= 0) && (offset <= nodeoffset);
         offset = fdt_next_node(fdt, offset, &depth)) {
        if (depth == supernodedepth)
            supernodeoffset = offset;

        if (offset == nodeoffset) {
            if (nodedepth)
                *nodedepth = depth;

            if (supernodedepth > depth)
                return -FDT_ERR_NOTFOUND;
            else
                return supernodeoffset;
        }
    }

    if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
        return -FDT_ERR_BADOFFSET;
    else if (offset == -FDT_ERR_BADOFFSET)
        return -FDT_ERR_BADSTRUCTURE;

    return offset; /* error from fdt_next_node() */
}

int fdt_node_depth(const void *fdt, int nodeoffset)
{
    int nodedepth;
    int err;

    err = fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, &nodedepth);
    if (err)
        return (err < 0) ? err : -FDT_ERR_INTERNAL;
    return nodedepth;
}

int fdt_parent_offset(const void *fdt, int nodeoffset)
{
    int nodedepth = fdt_node_depth(fdt, nodeoffset);

    if (nodedepth < 0)
        return nodedepth;
    return fdt_supernode_atdepth_offset(fdt, nodeoffset,
                        nodedepth - 1, NULL);
}

int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
                  const char *propname,
                  const void *propval, int proplen)
{
    int offset;
    const void *val;
    int len;

    FDT_CHECK_HEADER(fdt);

    /* FIXME: The algorithm here is pretty horrible: we scan each
     * property of a node in fdt_getprop(), then if that didn't
     * find what we want, we scan over them again making our way
     * to the next node.  Still it's the easiest to implement
     * approach; performance can come later. */
    for (offset = fdt_next_node(fdt, startoffset, NULL);
         offset >= 0;
         offset = fdt_next_node(fdt, offset, NULL)) {
        val = fdt_getprop(fdt, offset, propname, &len);
        if (val && (len == proplen)
            && (memcmp(val, propval, len) == 0))
            return offset;
    }

    return offset; /* error from fdt_next_node() */
}

int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle)
{
    int offset;

    if ((phandle == 0) || (phandle == -1))
        return -FDT_ERR_BADPHANDLE;

    FDT_CHECK_HEADER(fdt);

    /* FIXME: The algorithm here is pretty horrible: we
     * potentially scan each property of a node in
     * fdt_get_phandle(), then if that didn't find what
     * we want, we scan over them again making our way to the next
     * node.  Still it's the easiest to implement approach;
     * performance can come later. */
    for (offset = fdt_next_node(fdt, -1, NULL);
         offset >= 0;
         offset = fdt_next_node(fdt, offset, NULL)) {
        if (fdt_get_phandle(fdt, offset) == phandle)
            return offset;
    }

    return offset; /* error from fdt_next_node() */
}

static int _fdt_stringlist_contains(const char *strlist, int listlen,
                    const char *str)
{
    int len = strlen(str);
    const char *p;

    while (listlen >= len) {
        if (memcmp(str, strlist, len+1) == 0)
            return 1;
        p = memchr(strlist, '\0', listlen);
        if (!p)
            return 0; /* malformed strlist.. */
        listlen -= (p-strlist) + 1;
        strlist = p + 1;
    }
    return 0;
}

int fdt_node_check_compatible(const void *fdt, int nodeoffset,
                  const char *compatible)
{
    const void *prop;
    int len;

    prop = fdt_getprop(fdt, nodeoffset, "compatible", &len);
    if (!prop)
        return len;
    if (_fdt_stringlist_contains(prop, len, compatible))
        return 0;
    else
        return 1;
}

int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
                  const char *compatible)
{
    int offset, err;

    FDT_CHECK_HEADER(fdt);

    /* FIXME: The algorithm here is pretty horrible: we scan each
     * property of a node in fdt_node_check_compatible(), then if
     * that didn't find what we want, we scan over them again
     * making our way to the next node.  Still it's the easiest to
     * implement approach; performance can come later. */
    for (offset = fdt_next_node(fdt, startoffset, NULL);
         offset >= 0;
         offset = fdt_next_node(fdt, offset, NULL)) {
        err = fdt_node_check_compatible(fdt, offset, compatible);
        if ((err < 0) && (err != -FDT_ERR_NOTFOUND))
            return err;
        else if (err == 0)
            return offset;
    }

    return offset; /* error from fdt_next_node() */
}