diff options
| -rw-r--r-- | include/fdtdec.h | 47 | ||||
| -rw-r--r-- | lib/fdtdec.c | 116 |
2 files changed, 163 insertions, 0 deletions
diff --git a/include/fdtdec.h b/include/fdtdec.h index d871cdd..492431c 100644 --- a/include/fdtdec.h +++ b/include/fdtdec.h @@ -126,3 +126,50 @@ int fdtdec_get_is_enabled(const void *blob, int node, int default_val); * if not. */ int fdtdec_check_fdt(void); + +/** + * Find the nodes for a peripheral and return a list of them in the correct + * order. This is used to enumerate all the peripherals of a certain type. + * + * To use this, optionally set up a /aliases node with alias properties for + * a peripheral. For example, for usb you could have: + * + * aliases { + * usb0 = "/ehci@c5008000"; + * usb1 = "/ehci@c5000000"; + * }; + * + * Pass "usb" as the name to this function and will return a list of two + * nodes offsets: /ehci@c5008000 and ehci@c5000000. + * + * All nodes returned will match the compatible ID, as it is assumed that + * all peripherals use the same driver. + * + * If no alias node is found, then the node list will be returned in the + * order found in the fdt. If the aliases mention a node which doesn't + * exist, then this will be ignored. If nodes are found with no aliases, + * they will be added in any order. + * + * If there is a gap in the aliases, then this function return a 0 node at + * that position. The return value will also count these gaps. + * + * This function checks node properties and will not return nodes which are + * marked disabled (status = "disabled"). + * + * @param blob FDT blob to use + * @param name Root name of alias to search for + * @param id Compatible ID to look for + * @param node_list Place to put list of found nodes + * @param maxcount Maximum number of nodes to find + * @return number of nodes found on success, FTD_ERR_... on error + */ +int fdtdec_find_aliases_for_id(const void *blob, const char *name, + enum fdt_compat_id id, int *node_list, int maxcount); + +/* + * Get the name for a compatible ID + * + * @param id Compatible ID to look for + * @return compatible string for that id + */ +const char *fdtdec_get_compatible(enum fdt_compat_id id); diff --git a/lib/fdtdec.c b/lib/fdtdec.c index 0f87163..55d5bdf 100644 --- a/lib/fdtdec.c +++ b/lib/fdtdec.c @@ -35,6 +35,13 @@ DECLARE_GLOBAL_DATA_PTR; static const char * const compat_names[COMPAT_COUNT] = { }; +const char *fdtdec_get_compatible(enum fdt_compat_id id) +{ + /* We allow reading of the 'unknown' ID for testing purposes */ + assert(id >= 0 && id < COMPAT_COUNT); + return compat_names[id]; +} + /** * Look in the FDT for an alias with the given name and return its node. * @@ -132,6 +139,115 @@ int fdtdec_next_alias(const void *blob, const char *name, return err ? -FDT_ERR_NOTFOUND : node; } +/* TODO: Can we tighten this code up a little? */ +int fdtdec_find_aliases_for_id(const void *blob, const char *name, + enum fdt_compat_id id, int *node_list, int maxcount) +{ + int name_len = strlen(name); + int nodes[maxcount]; + int num_found = 0; + int offset, node; + int alias_node; + int count; + int i, j; + + /* find the alias node if present */ + alias_node = fdt_path_offset(blob, "/aliases"); + + /* + * start with nothing, and we can assume that the root node can't + * match + */ + memset(nodes, '\0', sizeof(nodes)); + + /* First find all the compatible nodes */ + for (node = count = 0; node >= 0 && count < maxcount;) { + node = fdtdec_next_compatible(blob, node, id); + if (node >= 0) + nodes[count++] = node; + } + if (node >= 0) + debug("%s: warning: maxcount exceeded with alias '%s'\n", + __func__, name); + + /* Now find all the aliases */ + memset(node_list, '\0', sizeof(*node_list) * maxcount); + + for (offset = fdt_first_property_offset(blob, alias_node); + offset > 0; + offset = fdt_next_property_offset(blob, offset)) { + const struct fdt_property *prop; + const char *path; + int number; + int found; + + node = 0; + prop = fdt_get_property_by_offset(blob, offset, NULL); + path = fdt_string(blob, fdt32_to_cpu(prop->nameoff)); + if (prop->len && 0 == strncmp(path, name, name_len)) + node = fdt_path_offset(blob, prop->data); + if (node <= 0) + continue; + + /* Get the alias number */ + number = simple_strtoul(path + name_len, NULL, 10); + if (number < 0 || number >= maxcount) { + debug("%s: warning: alias '%s' is out of range\n", + __func__, path); + continue; + } + + /* Make sure the node we found is actually in our list! */ + found = -1; + for (j = 0; j < count; j++) + if (nodes[j] == node) { + found = j; + break; + } + + if (found == -1) { + debug("%s: warning: alias '%s' points to a node " + "'%s' that is missing or is not compatible " + " with '%s'\n", __func__, path, + fdt_get_name(blob, node, NULL), + compat_names[id]); + continue; + } + + /* + * Add this node to our list in the right place, and mark + * it as done. + */ + if (fdtdec_get_is_enabled(blob, node)) { + node_list[number] = node; + if (number >= num_found) + num_found = number + 1; + } + nodes[j] = 0; + } + + /* Add any nodes not mentioned by an alias */ + for (i = j = 0; i < maxcount; i++) { + if (!node_list[i]) { + for (; j < maxcount; j++) + if (nodes[j] && + fdtdec_get_is_enabled(blob, nodes[j])) + break; + + /* Have we run out of nodes to add? */ + if (j == maxcount) + break; + + assert(!node_list[i]); + node_list[i] = nodes[j++]; + if (i >= num_found) + num_found = i + 1; + } + } + + return num_found; +} + /* * This function is a little odd in that it accesses global data. At some * point if the architecture board.c files merge this will make more sense. |