]> err.no Git - linux-2.6/blobdiff - drivers/of/base.c
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
[linux-2.6] / drivers / of / base.c
index 723d80d704e063575d667b031c5251a14f6054e1..9bd7c4a31253a5d7349d5b2fd3cb383e826d9680 100644 (file)
  */
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/spinlock.h>
+
+struct device_node *allnodes;
+
+/* use when traversing tree through the allnext, child, sibling,
+ * or parent members of struct device_node.
+ */
+DEFINE_RWLOCK(devtree_lock);
 
 int of_n_addr_cells(struct device_node *np)
 {
@@ -51,6 +59,26 @@ int of_n_size_cells(struct device_node *np)
 }
 EXPORT_SYMBOL(of_n_size_cells);
 
+struct property *of_find_property(const struct device_node *np,
+                                 const char *name,
+                                 int *lenp)
+{
+       struct property *pp;
+
+       read_lock(&devtree_lock);
+       for (pp = np->properties; pp != 0; pp = pp->next) {
+               if (of_prop_cmp(pp->name, name) == 0) {
+                       if (lenp != 0)
+                               *lenp = pp->length;
+                       break;
+               }
+       }
+       read_unlock(&devtree_lock);
+
+       return pp;
+}
+EXPORT_SYMBOL(of_find_property);
+
 /*
  * Find a property with a given name for a given node
  * and return the value.
@@ -63,3 +91,294 @@ const void *of_get_property(const struct device_node *np, const char *name,
        return pp ? pp->value : NULL;
 }
 EXPORT_SYMBOL(of_get_property);
+
+/** Checks if the given "compat" string matches one of the strings in
+ * the device's "compatible" property
+ */
+int of_device_is_compatible(const struct device_node *device,
+               const char *compat)
+{
+       const char* cp;
+       int cplen, l;
+
+       cp = of_get_property(device, "compatible", &cplen);
+       if (cp == NULL)
+               return 0;
+       while (cplen > 0) {
+               if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
+                       return 1;
+               l = strlen(cp) + 1;
+               cp += l;
+               cplen -= l;
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL(of_device_is_compatible);
+
+/**
+ *  of_device_is_available - check if a device is available for use
+ *
+ *  @device: Node to check for availability
+ *
+ *  Returns 1 if the status property is absent or set to "okay" or "ok",
+ *  0 otherwise
+ */
+int of_device_is_available(const struct device_node *device)
+{
+       const char *status;
+       int statlen;
+
+       status = of_get_property(device, "status", &statlen);
+       if (status == NULL)
+               return 1;
+
+       if (statlen > 0) {
+               if (!strcmp(status, "okay") || !strcmp(status, "ok"))
+                       return 1;
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL(of_device_is_available);
+
+/**
+ *     of_get_parent - Get a node's parent if any
+ *     @node:  Node to get parent
+ *
+ *     Returns a node pointer with refcount incremented, use
+ *     of_node_put() on it when done.
+ */
+struct device_node *of_get_parent(const struct device_node *node)
+{
+       struct device_node *np;
+
+       if (!node)
+               return NULL;
+
+       read_lock(&devtree_lock);
+       np = of_node_get(node->parent);
+       read_unlock(&devtree_lock);
+       return np;
+}
+EXPORT_SYMBOL(of_get_parent);
+
+/**
+ *     of_get_next_parent - Iterate to a node's parent
+ *     @node:  Node to get parent of
+ *
+ *     This is like of_get_parent() except that it drops the
+ *     refcount on the passed node, making it suitable for iterating
+ *     through a node's parents.
+ *
+ *     Returns a node pointer with refcount incremented, use
+ *     of_node_put() on it when done.
+ */
+struct device_node *of_get_next_parent(struct device_node *node)
+{
+       struct device_node *parent;
+
+       if (!node)
+               return NULL;
+
+       read_lock(&devtree_lock);
+       parent = of_node_get(node->parent);
+       of_node_put(node);
+       read_unlock(&devtree_lock);
+       return parent;
+}
+
+/**
+ *     of_get_next_child - Iterate a node childs
+ *     @node:  parent node
+ *     @prev:  previous child of the parent node, or NULL to get first
+ *
+ *     Returns a node pointer with refcount incremented, use
+ *     of_node_put() on it when done.
+ */
+struct device_node *of_get_next_child(const struct device_node *node,
+       struct device_node *prev)
+{
+       struct device_node *next;
+
+       read_lock(&devtree_lock);
+       next = prev ? prev->sibling : node->child;
+       for (; next; next = next->sibling)
+               if (of_node_get(next))
+                       break;
+       of_node_put(prev);
+       read_unlock(&devtree_lock);
+       return next;
+}
+EXPORT_SYMBOL(of_get_next_child);
+
+/**
+ *     of_find_node_by_path - Find a node matching a full OF path
+ *     @path:  The full path to match
+ *
+ *     Returns a node pointer with refcount incremented, use
+ *     of_node_put() on it when done.
+ */
+struct device_node *of_find_node_by_path(const char *path)
+{
+       struct device_node *np = allnodes;
+
+       read_lock(&devtree_lock);
+       for (; np; np = np->allnext) {
+               if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
+                   && of_node_get(np))
+                       break;
+       }
+       read_unlock(&devtree_lock);
+       return np;
+}
+EXPORT_SYMBOL(of_find_node_by_path);
+
+/**
+ *     of_find_node_by_name - Find a node by its "name" property
+ *     @from:  The node to start searching from or NULL, the node
+ *             you pass will not be searched, only the next one
+ *             will; typically, you pass what the previous call
+ *             returned. of_node_put() will be called on it
+ *     @name:  The name string to match against
+ *
+ *     Returns a node pointer with refcount incremented, use
+ *     of_node_put() on it when done.
+ */
+struct device_node *of_find_node_by_name(struct device_node *from,
+       const char *name)
+{
+       struct device_node *np;
+
+       read_lock(&devtree_lock);
+       np = from ? from->allnext : allnodes;
+       for (; np; np = np->allnext)
+               if (np->name && (of_node_cmp(np->name, name) == 0)
+                   && of_node_get(np))
+                       break;
+       of_node_put(from);
+       read_unlock(&devtree_lock);
+       return np;
+}
+EXPORT_SYMBOL(of_find_node_by_name);
+
+/**
+ *     of_find_node_by_type - Find a node by its "device_type" property
+ *     @from:  The node to start searching from, or NULL to start searching
+ *             the entire device tree. The node you pass will not be
+ *             searched, only the next one will; typically, you pass
+ *             what the previous call returned. of_node_put() will be
+ *             called on from for you.
+ *     @type:  The type string to match against
+ *
+ *     Returns a node pointer with refcount incremented, use
+ *     of_node_put() on it when done.
+ */
+struct device_node *of_find_node_by_type(struct device_node *from,
+       const char *type)
+{
+       struct device_node *np;
+
+       read_lock(&devtree_lock);
+       np = from ? from->allnext : allnodes;
+       for (; np; np = np->allnext)
+               if (np->type && (of_node_cmp(np->type, type) == 0)
+                   && of_node_get(np))
+                       break;
+       of_node_put(from);
+       read_unlock(&devtree_lock);
+       return np;
+}
+EXPORT_SYMBOL(of_find_node_by_type);
+
+/**
+ *     of_find_compatible_node - Find a node based on type and one of the
+ *                                tokens in its "compatible" property
+ *     @from:          The node to start searching from or NULL, the node
+ *                     you pass will not be searched, only the next one
+ *                     will; typically, you pass what the previous call
+ *                     returned. of_node_put() will be called on it
+ *     @type:          The type string to match "device_type" or NULL to ignore
+ *     @compatible:    The string to match to one of the tokens in the device
+ *                     "compatible" list.
+ *
+ *     Returns a node pointer with refcount incremented, use
+ *     of_node_put() on it when done.
+ */
+struct device_node *of_find_compatible_node(struct device_node *from,
+       const char *type, const char *compatible)
+{
+       struct device_node *np;
+
+       read_lock(&devtree_lock);
+       np = from ? from->allnext : allnodes;
+       for (; np; np = np->allnext) {
+               if (type
+                   && !(np->type && (of_node_cmp(np->type, type) == 0)))
+                       continue;
+               if (of_device_is_compatible(np, compatible) && of_node_get(np))
+                       break;
+       }
+       of_node_put(from);
+       read_unlock(&devtree_lock);
+       return np;
+}
+EXPORT_SYMBOL(of_find_compatible_node);
+
+/**
+ * of_match_node - Tell if an device_node has a matching of_match structure
+ *     @matches:       array of of device match structures to search in
+ *     @node:          the of device structure to match against
+ *
+ *     Low level utility function used by device matching.
+ */
+const struct of_device_id *of_match_node(const struct of_device_id *matches,
+                                        const struct device_node *node)
+{
+       while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
+               int match = 1;
+               if (matches->name[0])
+                       match &= node->name
+                               && !strcmp(matches->name, node->name);
+               if (matches->type[0])
+                       match &= node->type
+                               && !strcmp(matches->type, node->type);
+               if (matches->compatible[0])
+                       match &= of_device_is_compatible(node,
+                                               matches->compatible);
+               if (match)
+                       return matches;
+               matches++;
+       }
+       return NULL;
+}
+EXPORT_SYMBOL(of_match_node);
+
+/**
+ *     of_find_matching_node - Find a node based on an of_device_id match
+ *                             table.
+ *     @from:          The node to start searching from or NULL, the node
+ *                     you pass will not be searched, only the next one
+ *                     will; typically, you pass what the previous call
+ *                     returned. of_node_put() will be called on it
+ *     @matches:       array of of device match structures to search in
+ *
+ *     Returns a node pointer with refcount incremented, use
+ *     of_node_put() on it when done.
+ */
+struct device_node *of_find_matching_node(struct device_node *from,
+                                         const struct of_device_id *matches)
+{
+       struct device_node *np;
+
+       read_lock(&devtree_lock);
+       np = from ? from->allnext : allnodes;
+       for (; np; np = np->allnext) {
+               if (of_match_node(matches, np) && of_node_get(np))
+                       break;
+       }
+       of_node_put(from);
+       read_unlock(&devtree_lock);
+       return np;
+}
+EXPORT_SYMBOL(of_find_matching_node);