|
|
@@ -17,14 +17,39 @@
|
|
|
* as published by the Free Software Foundation; either version
|
|
|
* 2 of the License, or (at your option) any later version.
|
|
|
*/
|
|
|
+#include <linux/ctype.h>
|
|
|
#include <linux/module.h>
|
|
|
#include <linux/of.h>
|
|
|
#include <linux/spinlock.h>
|
|
|
#include <linux/slab.h>
|
|
|
#include <linux/proc_fs.h>
|
|
|
|
|
|
+/**
|
|
|
+ * struct alias_prop - Alias property in 'aliases' node
|
|
|
+ * @link: List node to link the structure in aliases_lookup list
|
|
|
+ * @alias: Alias property name
|
|
|
+ * @np: Pointer to device_node that the alias stands for
|
|
|
+ * @id: Index value from end of alias name
|
|
|
+ * @stem: Alias string without the index
|
|
|
+ *
|
|
|
+ * The structure represents one alias property of 'aliases' node as
|
|
|
+ * an entry in aliases_lookup list.
|
|
|
+ */
|
|
|
+struct alias_prop {
|
|
|
+ struct list_head link;
|
|
|
+ const char *alias;
|
|
|
+ struct device_node *np;
|
|
|
+ int id;
|
|
|
+ char stem[0];
|
|
|
+};
|
|
|
+
|
|
|
+static LIST_HEAD(aliases_lookup);
|
|
|
+
|
|
|
struct device_node *allnodes;
|
|
|
struct device_node *of_chosen;
|
|
|
+struct device_node *of_aliases;
|
|
|
+
|
|
|
+static DEFINE_MUTEX(of_aliases_mutex);
|
|
|
|
|
|
/* use when traversing tree through the allnext, child, sibling,
|
|
|
* or parent members of struct device_node.
|
|
|
@@ -988,3 +1013,108 @@ out_unlock:
|
|
|
}
|
|
|
#endif /* defined(CONFIG_OF_DYNAMIC) */
|
|
|
|
|
|
+static void of_alias_add(struct alias_prop *ap, struct device_node *np,
|
|
|
+ int id, const char *stem, int stem_len)
|
|
|
+{
|
|
|
+ ap->id = id;
|
|
|
+ ap->np = np;
|
|
|
+ strncpy(ap->stem, stem, stem_len);
|
|
|
+ ap->stem[stem_len] = 0;
|
|
|
+ list_add_tail(&ap->link, &aliases_lookup);
|
|
|
+ pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
|
|
|
+ ap->alias, ap->stem, ap->id, np ? np->full_name : NULL);
|
|
|
+}
|
|
|
+
|
|
|
+/**
|
|
|
+ * of_alias_scan() - Scan all properties of 'aliases' node
|
|
|
+ *
|
|
|
+ * The function scans all the properties of 'aliases' node and populate
|
|
|
+ * the global lookup table with the properties. It returns the
|
|
|
+ * number of alias_prop found, or error code in error case.
|
|
|
+ */
|
|
|
+__init void of_alias_scan(void)
|
|
|
+{
|
|
|
+ struct property *pp;
|
|
|
+
|
|
|
+ if (!of_aliases)
|
|
|
+ return;
|
|
|
+
|
|
|
+ for_each_property(pp, of_aliases->properties) {
|
|
|
+ const char *start = pp->name;
|
|
|
+ const char *end = start + strlen(start);
|
|
|
+ struct device_node *np;
|
|
|
+ struct alias_prop *ap;
|
|
|
+ int id, len;
|
|
|
+
|
|
|
+ /* Skip those we do not want to proceed */
|
|
|
+ if (!strcmp(pp->name, "name") ||
|
|
|
+ !strcmp(pp->name, "phandle") ||
|
|
|
+ !strcmp(pp->name, "linux,phandle"))
|
|
|
+ continue;
|
|
|
+
|
|
|
+ np = of_find_node_by_path(pp->value);
|
|
|
+ if (!np)
|
|
|
+ continue;
|
|
|
+
|
|
|
+ /* walk alias backwards to extract the id and 'stem' string */
|
|
|
+ while (isdigit(*(end-1)) && end > start)
|
|
|
+ end--;
|
|
|
+ len = end - start;
|
|
|
+ id = strlen(end) ? simple_strtoul(end, NULL, 10) : -1;
|
|
|
+
|
|
|
+ /* Allocate an alias_prop with enough space for the stem */
|
|
|
+ ap = early_init_dt_alloc_memory_arch(sizeof(*ap) + len + 1, 4);
|
|
|
+ if (!ap)
|
|
|
+ continue;
|
|
|
+ ap->alias = start;
|
|
|
+ of_alias_add(ap, np, id, start, len);
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+/**
|
|
|
+ * of_alias_get_id() - Get alias id for the given device_node
|
|
|
+ * @np: Pointer to the given device_node
|
|
|
+ * @stem: Alias stem of the given device_node
|
|
|
+ *
|
|
|
+ * The function travels the lookup table to get alias id for the given
|
|
|
+ * device_node and alias stem. It returns the alias id if find it.
|
|
|
+ * If not, dynamically creates one in the lookup table and returns it,
|
|
|
+ * or returns error code if fail to create.
|
|
|
+ */
|
|
|
+int of_alias_get_id(struct device_node *np, const char *stem)
|
|
|
+{
|
|
|
+ struct alias_prop *app;
|
|
|
+ int id = 0;
|
|
|
+ bool found = false;
|
|
|
+
|
|
|
+ mutex_lock(&of_aliases_mutex);
|
|
|
+ list_for_each_entry(app, &aliases_lookup, link) {
|
|
|
+ if (strcmp(app->stem, stem) != 0)
|
|
|
+ continue;
|
|
|
+
|
|
|
+ if (np == app->np) {
|
|
|
+ found = true;
|
|
|
+ id = app->id;
|
|
|
+ break;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (id <= app->id)
|
|
|
+ id = app->id + 1;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* If an id is not found, then allocate a new one */
|
|
|
+ if (!found) {
|
|
|
+ app = kzalloc(sizeof(*app) + strlen(stem) + 1, 4);
|
|
|
+ if (!app) {
|
|
|
+ id = -ENODEV;
|
|
|
+ goto out;
|
|
|
+ }
|
|
|
+ of_alias_add(app, np, id, stem, strlen(stem));
|
|
|
+ }
|
|
|
+
|
|
|
+ out:
|
|
|
+ mutex_unlock(&of_aliases_mutex);
|
|
|
+
|
|
|
+ return id;
|
|
|
+}
|
|
|
+EXPORT_SYMBOL_GPL(of_alias_get_id);
|
Linus Torvalds