Committer: Michael Beasley <mike@snafu.setup>

[mikesnafu-overlay.git] / arch / powerpc / boot / libfdt / fdt_ro.c

/*
 * 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"

#define CHECK_HEADER(fdt) \
        { \
                int err; \
                if ((err = fdt_check_header(fdt)) != 0) \
                        return err; \
        }

static int nodename_eq(const void *fdt, int offset,
                       const char *s, int len)
{
        const char *p = fdt_offset_ptr(fdt, offset, 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 (char *)fdt + fdt_off_dt_strings(fdt) + stroffset;
}

int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size)
{
        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;
}

int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
                               const char *name, int namelen)
{
        int level = 0;
        uint32_t tag;
        int offset, nextoffset;

        CHECK_HEADER(fdt);

        tag = fdt_next_tag(fdt, parentoffset, &nextoffset);
        if (tag != FDT_BEGIN_NODE)
                return -FDT_ERR_BADOFFSET;

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

                switch (tag) {
                case FDT_END:
                        return -FDT_ERR_TRUNCATED;

                case FDT_BEGIN_NODE:
                        level++;
                        if (level != 1)
                                continue;
                        if (nodename_eq(fdt, offset+FDT_TAGSIZE, name, namelen))
                                /* Found it! */
                                return offset;
                        break;

                case FDT_END_NODE:
                        level--;
                        break;

                case FDT_PROP:
                case FDT_NOP:
                        break;

                default:
                        return -FDT_ERR_BADSTRUCTURE;
                }
        } while (level >= 0);

        return -FDT_ERR_NOTFOUND;
}

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;

        CHECK_HEADER(fdt);

        if (*path != '/')
                return -FDT_ERR_BADPATH;

        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;
        int err;

        if ((err = fdt_check_header(fdt)) != 0)
                goto fail;

        err = -FDT_ERR_BADOFFSET;
        nh = fdt_offset_ptr(fdt, nodeoffset, sizeof(*nh));
        if (!nh || (fdt32_to_cpu(nh->tag) != FDT_BEGIN_NODE))
                goto fail;

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

        return nh->name;

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

const struct fdt_property *fdt_get_property(const void *fdt,
                                            int nodeoffset,
                                            const char *name, int *lenp)
{
        uint32_t tag;
        const struct fdt_property *prop;
        int namestroff;
        int offset, nextoffset;
        int err;

        if ((err = fdt_check_header(fdt)) != 0)
                goto fail;

        err = -FDT_ERR_BADOFFSET;
        if (nodeoffset % FDT_TAGSIZE)
                goto fail;

        tag = fdt_next_tag(fdt, nodeoffset, &nextoffset);
        if (tag != FDT_BEGIN_NODE)
                goto fail;

        do {
                offset = nextoffset;

                tag = fdt_next_tag(fdt, offset, &nextoffset);
                switch (tag) {
                case FDT_END:
                        err = -FDT_ERR_TRUNCATED;
                        goto fail;

                case FDT_BEGIN_NODE:
                case FDT_END_NODE:
                case FDT_NOP:
                        break;

                case FDT_PROP:
                        err = -FDT_ERR_BADSTRUCTURE;
                        prop = fdt_offset_ptr(fdt, offset, sizeof(*prop));
                        if (! prop)
                                goto fail;
                        namestroff = fdt32_to_cpu(prop->nameoff);
                        if (streq(fdt_string(fdt, namestroff), name)) {
                                /* Found it! */
                                int len = fdt32_to_cpu(prop->len);
                                prop = fdt_offset_ptr(fdt, offset,
                                                      sizeof(*prop)+len);
                                if (! prop)
                                        goto fail;

                                if (lenp)
                                        *lenp = len;

                                return prop;
                        }
                        break;

                default:
                        err = -FDT_ERR_BADSTRUCTURE;
                        goto fail;
                }
        } while ((tag != FDT_BEGIN_NODE) && (tag != FDT_END_NODE));

        err = -FDT_ERR_NOTFOUND;
 fail:
        if (lenp)
                *lenp = err;
        return NULL;
}

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

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

        return prop->data;
}

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

        php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len);
        if (!php || (len != sizeof(*php)))
                return 0;

        return fdt32_to_cpu(*php);
}

int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen)
{
        uint32_t tag;
        int p = 0, overflow = 0;
        int offset, nextoffset, namelen;
        const char *name;

        CHECK_HEADER(fdt);

        tag = fdt_next_tag(fdt, 0, &nextoffset);
        if (tag != FDT_BEGIN_NODE)
                return -FDT_ERR_BADSTRUCTURE;

        if (buflen < 2)
                return -FDT_ERR_NOSPACE;
        buf[0] = '/';
        p = 1;

        while (nextoffset <= nodeoffset) {
                offset = nextoffset;
                tag = fdt_next_tag(fdt, offset, &nextoffset);
                switch (tag) {
                case FDT_END:
                        return -FDT_ERR_BADOFFSET;

                case FDT_BEGIN_NODE:
                        name = fdt_get_name(fdt, offset, &namelen);
                        if (!name)
                                return namelen;
                        if (overflow || ((p + namelen + 1) > buflen)) {
                                overflow++;
                                break;
                        }
                        memcpy(buf + p, name, namelen);
                        p += namelen;
                        buf[p++] = '/';
                        break;

                case FDT_END_NODE:
                        if (overflow) {
                                overflow--;
                                break;
                        }
                        do {
                                p--;
                        } while  (buf[p-1] != '/');
                        break;

                case FDT_PROP:
                case FDT_NOP:
                        break;

                default:
                        return -FDT_ERR_BADSTRUCTURE;
                }
        }

        if (overflow)
                return -FDT_ERR_NOSPACE;

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

int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
                                 int supernodedepth, int *nodedepth)
{
        int level = -1;
        uint32_t tag;
        int offset, nextoffset = 0;
        int supernodeoffset = -FDT_ERR_INTERNAL;

        CHECK_HEADER(fdt);

        if (supernodedepth < 0)
                return -FDT_ERR_NOTFOUND;

        do {
                offset = nextoffset;
                tag = fdt_next_tag(fdt, offset, &nextoffset);
                switch (tag) {
                case FDT_END:
                        return -FDT_ERR_BADOFFSET;

                case FDT_BEGIN_NODE:
                        level++;
                        if (level == supernodedepth)
                                supernodeoffset = offset;
                        break;

                case FDT_END_NODE:
                        level--;
                        break;

                case FDT_PROP:
                case FDT_NOP:
                        break;

                default:
                        return -FDT_ERR_BADSTRUCTURE;
                }
        } while (offset < nodeoffset);

        if (nodedepth)
                *nodedepth = level;

        if (supernodedepth > level)
                return -FDT_ERR_NOTFOUND;
        return supernodeoffset;
}

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)
{
        uint32_t tag;
        int offset, nextoffset;
        const void *val;
        int len;

        CHECK_HEADER(fdt);

        if (startoffset >= 0) {
                tag = fdt_next_tag(fdt, startoffset, &nextoffset);
                if (tag != FDT_BEGIN_NODE)
                        return -FDT_ERR_BADOFFSET;
        } else {
                nextoffset = 0;
        }

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

                switch (tag) {
                case FDT_BEGIN_NODE:
                        val = fdt_getprop(fdt, offset, propname, &len);
                        if (val
                            && (len == proplen)
                            && (memcmp(val, propval, len) == 0))
                                return offset;
                        break;

                case FDT_PROP:
                case FDT_END:
                case FDT_END_NODE:
                case FDT_NOP:
                        break;

                default:
                        return -FDT_ERR_BADSTRUCTURE;
                }
        } while (tag != FDT_END);

        return -FDT_ERR_NOTFOUND;
}

int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle)
{
        if ((phandle == 0) || (phandle == -1))
                return -FDT_ERR_BADPHANDLE;
        phandle = cpu_to_fdt32(phandle);
        return fdt_node_offset_by_prop_value(fdt, -1, "linux,phandle",
                                             &phandle, sizeof(phandle));
}

int _stringlist_contains(const void *strlist, int listlen, const char *str)
{
        int len = strlen(str);
        const void *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 (_stringlist_contains(prop, len, compatible))
                return 0;
        else
                return 1;
}

int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
                                  const char *compatible)
{
        uint32_t tag;
        int offset, nextoffset;
        int err;

        CHECK_HEADER(fdt);

        if (startoffset >= 0) {
                tag = fdt_next_tag(fdt, startoffset, &nextoffset);
                if (tag != FDT_BEGIN_NODE)
                        return -FDT_ERR_BADOFFSET;
        } else {
                nextoffset = 0;
        }

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

                switch (tag) {
                case FDT_BEGIN_NODE:
                        err = fdt_node_check_compatible(fdt, offset,
                                                        compatible);
                        if ((err < 0)
                            && (err != -FDT_ERR_NOTFOUND))
                                return err;
                        else if (err == 0)
                                return offset;
                        break;

                case FDT_PROP:
                case FDT_END:
                case FDT_END_NODE:
                case FDT_NOP:
                        break;

                default:
                        return -FDT_ERR_BADSTRUCTURE;
                }
        } while (tag != FDT_END);

        return -FDT_ERR_NOTFOUND;
}