diff options
Diffstat (limited to 'libfdt/fdt_ro.c')
| -rw-r--r-- | libfdt/fdt_ro.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/libfdt/fdt_ro.c b/libfdt/fdt_ro.c new file mode 100644 index 0000000..9112c6a --- /dev/null +++ b/libfdt/fdt_ro.c @@ -0,0 +1,229 @@ +/* + * libfdt - Flat Device Tree manipulation + * Copyright (C) 2006 David Gibson, IBM Corporation. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public License + * as published by the Free Software Foundation; either version 2.1 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser 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 + */ +#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 offset_streq(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 0; + + return 1; +} + +char *fdt_string(const void *fdt, int stroffset) +{ + return (char *)fdt + fdt_off_dt_strings(fdt) + stroffset; +} + +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 (offset_streq(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 -FDT_ERR_BADPATH; + 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; +} + +struct fdt_property *fdt_get_property(const void *fdt, + int nodeoffset, + const char *name, int *lenp) +{ + int level = 0; + uint32_t tag; + 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: + level++; + break; + + case FDT_END_NODE: + level--; + break; + + case FDT_PROP: + if (level != 0) + continue; + + err = -FDT_ERR_BADSTRUCTURE; + prop = fdt_offset_ptr_typed(fdt, offset, 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; + + case FDT_NOP: + break; + + default: + err = -FDT_ERR_BADSTRUCTURE; + goto fail; + } + } while (level >= 0); + + err = -FDT_ERR_NOTFOUND; + fail: + if (lenp) + *lenp = err; + return NULL; +} + +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; +} |