From 9675ee7208ab965d13ea8d8262d77ac4160ef549 Mon Sep 17 00:00:00 2001 From: Gerald Van Baren Date: Thu, 17 May 2007 23:54:36 -0400 Subject: Add fdt_find_node_by_type() and fdt_find_compatible_node() to LIBFDT Signed-off-by: Wolfgang Grandegger Acked-by: Gerald Van Baren --- libfdt/fdt_ro.c | 161 +++++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 143 insertions(+), 18 deletions(-) (limited to 'libfdt') diff --git a/libfdt/fdt_ro.c b/libfdt/fdt_ro.c index 1a03109e81..923c389ece 100644 --- a/libfdt/fdt_ro.c +++ b/libfdt/fdt_ro.c @@ -50,6 +50,33 @@ static int offset_streq(const void *fdt, int offset, return 1; } +/* + * Checks if the property name matches. + */ +static int prop_name_eq(const void *fdt, int offset, const char *name, + struct fdt_property **prop, int *lenp) +{ + int namestroff, len; + + *prop = fdt_offset_ptr_typed(fdt, offset, *prop); + if (! *prop) + return -FDT_ERR_BADSTRUCTURE; + + namestroff = fdt32_to_cpu((*prop)->nameoff); + if (streq(fdt_string(fdt, namestroff), name)) { + len = fdt32_to_cpu((*prop)->len); + *prop = fdt_offset_ptr(fdt, offset, + sizeof(**prop) + len); + if (*prop) { + if (lenp) + *lenp = len; + return 1; + } else + return -FDT_ERR_BADSTRUCTURE; + } + return 0; +} + /* * Return a pointer to the string at the given string offset. */ @@ -58,6 +85,118 @@ char *fdt_string(const void *fdt, int stroffset) return (char *)fdt + fdt_off_dt_strings(fdt) + stroffset; } +/* + * Check if the specified node is compatible by comparing the tokens + * in its "compatible" property with the specified string: + * + * nodeoffset - starting place of the node + * compat - the string to match to one of the tokens in the + * "compatible" list. + */ +int fdt_node_is_compatible(const void *fdt, int nodeoffset, + const char *compat) +{ + const char* cp; + int cplen, len; + + cp = fdt_getprop(fdt, nodeoffset, "compatible", &cplen); + if (cp == NULL) + return 0; + while (cplen > 0) { + if (strncmp(cp, compat, strlen(compat)) == 0) + return 1; + len = strlen(cp) + 1; + cp += len; + cplen -= len; + } + + return 0; +} + +/* + * Find a node by its device type property. On success, the offset of that + * node is returned or an error code otherwise: + * + * nodeoffset - the node to start searching from or 0, the node you pass + * will not be searched, only the next one will; typically, + * you pass 0 to start the search and then what the previous + * call returned. + * type - the device type string to match against. + */ +int fdt_find_node_by_type(const void *fdt, int nodeoffset, const char *type) +{ + int offset, nextoffset; + struct fdt_property *prop; + uint32_t tag; + int len, ret; + + CHECK_HEADER(fdt); + + tag = fdt_next_tag(fdt, nodeoffset, &nextoffset, NULL); + if (tag != FDT_BEGIN_NODE) + return -FDT_ERR_BADOFFSET; + if (nodeoffset) + nodeoffset = 0; /* start searching with next node */ + + while (1) { + offset = nextoffset; + tag = fdt_next_tag(fdt, offset, &nextoffset, NULL); + + switch (tag) { + case FDT_BEGIN_NODE: + nodeoffset = offset; + break; + + case FDT_PROP: + if (nodeoffset == 0) + break; + ret = prop_name_eq(fdt, offset, "device_type", + &prop, &len); + if (ret < 0) + return ret; + else if (ret > 0 && + strncmp(prop->data, type, len - 1) == 0) + return nodeoffset; + break; + + case FDT_END_NODE: + case FDT_NOP: + break; + + case FDT_END: + return -FDT_ERR_NOTFOUND; + + default: + return -FDT_ERR_BADSTRUCTURE; + } + } +} + +/* + * Find a node based on its device type and one of the tokens in its its + * "compatible" property. On success, the offset of that node is returned + * or an error code otherwise: + * + * nodeoffset - the node to start searching from or 0, the node you pass + * will not be searched, only the next one will; typically, + * you pass 0 to start the search and then what the previous + * call returned. + * type - the device type string to match against. + * compat - the string to match to one of the tokens in the + * "compatible" list. + */ +int fdt_find_compatible_node(const void *fdt, int nodeoffset, + const char *type, const char *compat) +{ + int offset; + + offset = fdt_find_node_by_type(fdt, nodeoffset, type); + if (offset < 0 || fdt_node_is_compatible(fdt, offset, compat)) + return offset; + + return -FDT_ERR_NOTFOUND; +} + /* * Return the node offset of the node specified by: * parentoffset - starting place (0 to start at the root) @@ -187,7 +326,6 @@ struct fdt_property *fdt_get_property(const void *fdt, int level = 0; uint32_t tag; struct fdt_property *prop; - int namestroff; int offset, nextoffset; int err; @@ -227,24 +365,11 @@ struct fdt_property *fdt_get_property(const void *fdt, 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; - + err = prop_name_eq(fdt, offset, name, &prop, lenp); + if (err > 0) return prop; - } + else if (err < 0) + goto fail; break; case FDT_NOP: -- cgit v1.2.1