Linux-libre 4.6.2-gnu

1 files changed, 80 insertions, 141 deletions

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index b4db67a44..fb74dc1f7 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -350,13 +350,12 @@ static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
 {
 	if (!core || index >= core->num_parents)
 		return NULL;
-	else if (!core->parents)
-		return clk_core_lookup(core->parent_names[index]);
-	else if (!core->parents[index])
-		return core->parents[index] =
-			clk_core_lookup(core->parent_names[index]);
-	else
-		return core->parents[index];
+
+	if (!core->parents[index])
+		core->parents[index] =
+				clk_core_lookup(core->parent_names[index]);
+
+	return core->parents[index];
 }
 
 struct clk_hw *
@@ -386,7 +385,7 @@ static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
 
 	ret = core->rate;
 
-	if (core->flags & CLK_IS_ROOT)
+	if (!core->num_parents)
 		goto out;
 
 	if (!core->parent)
@@ -1067,30 +1066,12 @@ static int clk_fetch_parent_index(struct clk_core *core,
 {
 	int i;
 
-	if (!core->parents) {
-		core->parents = kcalloc(core->num_parents,
-					sizeof(struct clk *), GFP_KERNEL);
-		if (!core->parents)
-			return -ENOMEM;
-	}
-
-	/*
-	 * find index of new parent clock using cached parent ptrs,
-	 * or if not yet cached, use string name comparison and cache
-	 * them now to avoid future calls to clk_core_lookup.
-	 */
-	for (i = 0; i < core->num_parents; i++) {
-		if (core->parents[i] == parent)
-			return i;
-
-		if (core->parents[i])
-			continue;
+	if (!parent)
+		return -EINVAL;
 
-		if (!strcmp(core->parent_names[i], parent->name)) {
-			core->parents[i] = clk_core_lookup(parent->name);
+	for (i = 0; i < core->num_parents; i++)
+		if (clk_core_get_parent_by_index(core, i) == parent)
 			return i;
-		}
-	}
 
 	return -EINVAL;
 }
@@ -1677,56 +1658,14 @@ struct clk *clk_get_parent(struct clk *clk)
 }
 EXPORT_SYMBOL_GPL(clk_get_parent);
 
-/*
- * .get_parent is mandatory for clocks with multiple possible parents.  It is
- * optional for single-parent clocks.  Always call .get_parent if it is
- * available and WARN if it is missing for multi-parent clocks.
- *
- * For single-parent clocks without .get_parent, first check to see if the
- * .parents array exists, and if so use it to avoid an expensive tree
- * traversal.  If .parents does not exist then walk the tree.
- */
 static struct clk_core *__clk_init_parent(struct clk_core *core)
 {
-	struct clk_core *ret = NULL;
-	u8 index;
+	u8 index = 0;
 
-	/* handle the trivial cases */
+	if (core->num_parents > 1 && core->ops->get_parent)
+		index = core->ops->get_parent(core->hw);
 
-	if (!core->num_parents)
-		goto out;
-
-	if (core->num_parents == 1) {
-		if (IS_ERR_OR_NULL(core->parent))
-			core->parent = clk_core_lookup(core->parent_names[0]);
-		ret = core->parent;
-		goto out;
-	}
-
-	if (!core->ops->get_parent) {
-		WARN(!core->ops->get_parent,
-			"%s: multi-parent clocks must implement .get_parent\n",
-			__func__);
-		goto out;
-	}
-
-	/*
-	 * Do our best to cache parent clocks in core->parents.  This prevents
-	 * unnecessary and expensive lookups.  We don't set core->parent here;
-	 * that is done by the calling function.
-	 */
-
-	index = core->ops->get_parent(core->hw);
-
-	if (!core->parents)
-		core->parents =
-			kcalloc(core->num_parents, sizeof(struct clk *),
-					GFP_KERNEL);
-
-	ret = clk_core_get_parent_by_index(core, index);
-
-out:
-	return ret;
+	return clk_core_get_parent_by_index(core, index);
 }
 
 static void clk_core_reparent(struct clk_core *core,
@@ -1809,13 +1748,13 @@ static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent)
 	/* try finding the new parent index */
 	if (parent) {
 		p_index = clk_fetch_parent_index(core, parent);
-		p_rate = parent->rate;
 		if (p_index < 0) {
 			pr_debug("%s: clk %s can not be parent of clk %s\n",
 					__func__, parent->name, core->name);
 			ret = p_index;
 			goto out;
 		}
+		p_rate = parent->rate;
 	}
 
 	/* propagate PRE_RATE_CHANGE notifications */
@@ -1902,6 +1841,10 @@ int clk_set_phase(struct clk *clk, int degrees)
 
 	clk_prepare_lock();
 
+	/* bail early if nothing to do */
+	if (degrees == clk->core->phase)
+		goto out;
+
 	trace_clk_set_phase(clk->core, degrees);
 
 	if (clk->core->ops->set_phase)
@@ -1912,6 +1855,7 @@ int clk_set_phase(struct clk *clk, int degrees)
 	if (!ret)
 		clk->core->phase = degrees;
 
+out:
 	clk_prepare_unlock();
 
 	return ret;
@@ -2218,7 +2162,7 @@ unlock:
  *
  * Dynamically removes a clk and all its child nodes from the
  * debugfs clk directory if clk->dentry points to debugfs created by
- * clk_debug_register in __clk_init.
+ * clk_debug_register in __clk_core_init.
  */
 static void clk_debug_unregister(struct clk_core *core)
 {
@@ -2303,26 +2247,22 @@ static inline void clk_debug_unregister(struct clk_core *core)
 #endif
 
 /**
- * __clk_init - initialize the data structures in a struct clk
- * @dev:	device initializing this clk, placeholder for now
- * @clk:	clk being initialized
+ * __clk_core_init - initialize the data structures in a struct clk_core
+ * @core:	clk_core being initialized
  *
  * Initializes the lists in struct clk_core, queries the hardware for the
  * parent and rate and sets them both.
  */
-static int __clk_init(struct device *dev, struct clk *clk_user)
+static int __clk_core_init(struct clk_core *core)
 {
 	int i, ret = 0;
 	struct clk_core *orphan;
 	struct hlist_node *tmp2;
-	struct clk_core *core;
 	unsigned long rate;
 
-	if (!clk_user)
+	if (!core)
 		return -EINVAL;
 
-	core = clk_user->core;
-
 	clk_prepare_lock();
 
 	/* check to see if a clock with this name is already registered */
@@ -2337,22 +2277,29 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
 	if (core->ops->set_rate &&
 	    !((core->ops->round_rate || core->ops->determine_rate) &&
 	      core->ops->recalc_rate)) {
-		pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
-				__func__, core->name);
+		pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
+		       __func__, core->name);
 		ret = -EINVAL;
 		goto out;
 	}
 
 	if (core->ops->set_parent && !core->ops->get_parent) {
-		pr_warning("%s: %s must implement .get_parent & .set_parent\n",
-				__func__, core->name);
+		pr_err("%s: %s must implement .get_parent & .set_parent\n",
+		       __func__, core->name);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (core->num_parents > 1 && !core->ops->get_parent) {
+		pr_err("%s: %s must implement .get_parent as it has multi parents\n",
+		       __func__, core->name);
 		ret = -EINVAL;
 		goto out;
 	}
 
 	if (core->ops->set_rate_and_parent &&
 			!(core->ops->set_parent && core->ops->set_rate)) {
-		pr_warn("%s: %s must implement .set_parent & .set_rate\n",
+		pr_err("%s: %s must implement .set_parent & .set_rate\n",
 				__func__, core->name);
 		ret = -EINVAL;
 		goto out;
@@ -2364,37 +2311,12 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
 				"%s: invalid NULL in %s's .parent_names\n",
 				__func__, core->name);
 
-	/*
-	 * Allocate an array of struct clk *'s to avoid unnecessary string
-	 * look-ups of clk's possible parents.  This can fail for clocks passed
-	 * in to clk_init during early boot; thus any access to core->parents[]
-	 * must always check for a NULL pointer and try to populate it if
-	 * necessary.
-	 *
-	 * If core->parents is not NULL we skip this entire block.  This allows
-	 * for clock drivers to statically initialize core->parents.
-	 */
-	if (core->num_parents > 1 && !core->parents) {
-		core->parents = kcalloc(core->num_parents, sizeof(struct clk *),
-					GFP_KERNEL);
-		/*
-		 * clk_core_lookup returns NULL for parents that have not been
-		 * clk_init'd; thus any access to clk->parents[] must check
-		 * for a NULL pointer.  We can always perform lazy lookups for
-		 * missing parents later on.
-		 */
-		if (core->parents)
-			for (i = 0; i < core->num_parents; i++)
-				core->parents[i] =
-					clk_core_lookup(core->parent_names[i]);
-	}
-
 	core->parent = __clk_init_parent(core);
 
 	/*
-	 * Populate core->parent if parent has already been __clk_init'd.  If
-	 * parent has not yet been __clk_init'd then place clk in the orphan
-	 * list.  If clk has set the CLK_IS_ROOT flag then place it in the root
+	 * Populate core->parent if parent has already been clk_core_init'd. If
+	 * parent has not yet been clk_core_init'd then place clk in the orphan
+	 * list.  If clk doesn't have any parents then place it in the root
 	 * clk list.
 	 *
 	 * Every time a new clk is clk_init'd then we walk the list of orphan
@@ -2405,7 +2327,7 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
 		hlist_add_head(&core->child_node,
 				&core->parent->children);
 		core->orphan = core->parent->orphan;
-	} else if (core->flags & CLK_IS_ROOT) {
+	} else if (!core->num_parents) {
 		hlist_add_head(&core->child_node, &clk_root_list);
 		core->orphan = false;
 	} else {
@@ -2454,24 +2376,15 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
 	core->rate = core->req_rate = rate;
 
 	/*
-	 * walk the list of orphan clocks and reparent any that are children of
-	 * this clock
+	 * walk the list of orphan clocks and reparent any that newly finds a
+	 * parent.
 	 */
 	hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
-		if (orphan->num_parents && orphan->ops->get_parent) {
-			i = orphan->ops->get_parent(orphan->hw);
-			if (i >= 0 && i < orphan->num_parents &&
-			    !strcmp(core->name, orphan->parent_names[i]))
-				clk_core_reparent(orphan, core);
-			continue;
-		}
+		struct clk_core *parent = __clk_init_parent(orphan);
 
-		for (i = 0; i < orphan->num_parents; i++)
-			if (!strcmp(core->name, orphan->parent_names[i])) {
-				clk_core_reparent(orphan, core);
-				break;
-			}
-	 }
+		if (parent)
+			clk_core_reparent(orphan, parent);
+	}
 
 	/*
 	 * optional platform-specific magic
@@ -2585,21 +2498,31 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw)
 		}
 	}
 
+	/* avoid unnecessary string look-ups of clk_core's possible parents. */
+	core->parents = kcalloc(core->num_parents, sizeof(*core->parents),
+				GFP_KERNEL);
+	if (!core->parents) {
+		ret = -ENOMEM;
+		goto fail_parents;
+	};
+
 	INIT_HLIST_HEAD(&core->clks);
 
 	hw->clk = __clk_create_clk(hw, NULL, NULL);
 	if (IS_ERR(hw->clk)) {
 		ret = PTR_ERR(hw->clk);
-		goto fail_parent_names_copy;
+		goto fail_parents;
 	}
 
-	ret = __clk_init(dev, hw->clk);
+	ret = __clk_core_init(core);
 	if (!ret)
 		return hw->clk;
 
 	__clk_free_clk(hw->clk);
 	hw->clk = NULL;
 
+fail_parents:
+	kfree(core->parents);
 fail_parent_names_copy:
 	while (--i >= 0)
 		kfree_const(core->parent_names[i]);
@@ -2683,7 +2606,7 @@ void clk_unregister(struct clk *clk)
 	if (clk->core->ops == &clk_nodrv_ops) {
 		pr_err("%s: unregistered clock: %s\n", __func__,
 		       clk->core->name);
-		return;
+		goto unlock;
 	}
 	/*
 	 * Assign empty clock ops for consumers that might still hold
@@ -2709,7 +2632,7 @@ void clk_unregister(struct clk *clk)
 		pr_warn("%s: unregistering prepared clock: %s\n",
 					__func__, clk->core->name);
 	kref_put(&clk->core->ref, __clk_release);
-
+unlock:
 	clk_prepare_unlock();
 }
 EXPORT_SYMBOL_GPL(clk_unregister);
@@ -3061,10 +2984,23 @@ struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
 {
 	return __of_clk_get_from_provider(clkspec, NULL, __func__);
 }
+EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
 
-int of_clk_get_parent_count(struct device_node *np)
+/**
+ * of_clk_get_parent_count() - Count the number of clocks a device node has
+ * @np: device node to count
+ *
+ * Returns: The number of clocks that are possible parents of this node
+ */
+unsigned int of_clk_get_parent_count(struct device_node *np)
 {
-	return of_count_phandle_with_args(np, "clocks", "#clock-cells");
+	int count;
+
+	count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
+	if (count < 0)
+		return 0;
+
+	return count;
 }
 EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
 
@@ -3214,6 +3150,9 @@ void __init of_clk_init(const struct of_device_id *matches)
 	for_each_matching_node_and_match(np, matches, &match) {
 		struct clock_provider *parent;
 
+		if (!of_device_is_available(np))
+			continue;
+
 		parent = kzalloc(sizeof(*parent), GFP_KERNEL);
 		if (!parent) {
 			list_for_each_entry_safe(clk_provider, next,