clk: track the orphan status of clocks and their children

[firefly-linux-kernel-4.4.55.git] / drivers / clk / clk.c

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 898052ee0efade136d385e3e8e3a158b36750ebd..4912c2e55e2c475c7f6c6763e9a3b9891cdbd521 100644 (file)
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -57,6 +57,7 @@ struct clk_core {
        struct clk_core         *new_parent;
        struct clk_core         *new_child;
        unsigned long           flags;
+       bool                    orphan;
        unsigned int            enable_count;
        unsigned int            prepare_count;
        unsigned long           min_rate;
@@ -1091,18 +1092,40 @@ static int clk_fetch_parent_index(struct clk_core *core,
        return -EINVAL;
 }
 
+/*
+ * Update the orphan status of @core and all its children.
+ */
+static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
+{
+       struct clk_core *child;
+
+       core->orphan = is_orphan;
+
+       hlist_for_each_entry(child, &core->children, child_node)
+               clk_core_update_orphan_status(child, is_orphan);
+}
+
 static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
 {
+       bool was_orphan = core->orphan;
+
        hlist_del(&core->child_node);
 
        if (new_parent) {
+               bool becomes_orphan = new_parent->orphan;
+
                /* avoid duplicate POST_RATE_CHANGE notifications */
                if (new_parent->new_child == core)
                        new_parent->new_child = NULL;
 
                hlist_add_head(&core->child_node, &new_parent->children);
+
+               if (was_orphan != becomes_orphan)
+                       clk_core_update_orphan_status(core, becomes_orphan);
        } else {
                hlist_add_head(&core->child_node, &clk_orphan_list);
+               if (!was_orphan)
+                       clk_core_update_orphan_status(core, true);
        }
 
        core->parent = new_parent;
@@ -2359,13 +2382,17 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
         * clocks and re-parent any that are children of the clock currently
         * being clk_init'd.
         */
-       if (core->parent)
+       if (core->parent) {
                hlist_add_head(&core->child_node,
                                &core->parent->children);
-       else if (core->flags & CLK_IS_ROOT)
+               core->orphan = core->parent->orphan;
+       } else if (core->flags & CLK_IS_ROOT) {
                hlist_add_head(&core->child_node, &clk_root_list);
-       else
+               core->orphan = false;
+       } else {
                hlist_add_head(&core->child_node, &clk_orphan_list);
+               core->orphan = true;
+       }
 
        /*
         * Set clk's accuracy.  The preferred method is to use