1 files changed, 204 insertions, 143 deletions

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index d584004f7af7..820a939fb6bb 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -172,104 +172,6 @@ static bool clk_core_is_enabled(struct clk_core *core)
 	return core->ops->is_enabled(core->hw);
 }
 
-static void clk_unprepare_unused_subtree(struct clk_core *core)
-{
-	struct clk_core *child;
-
-	lockdep_assert_held(&prepare_lock);
-
-	hlist_for_each_entry(child, &core->children, child_node)
-		clk_unprepare_unused_subtree(child);
-
-	if (core->prepare_count)
-		return;
-
-	if (core->flags & CLK_IGNORE_UNUSED)
-		return;
-
-	if (clk_core_is_prepared(core)) {
-		trace_clk_unprepare(core);
-		if (core->ops->unprepare_unused)
-			core->ops->unprepare_unused(core->hw);
-		else if (core->ops->unprepare)
-			core->ops->unprepare(core->hw);
-		trace_clk_unprepare_complete(core);
-	}
-}
-
-static void clk_disable_unused_subtree(struct clk_core *core)
-{
-	struct clk_core *child;
-	unsigned long flags;
-
-	lockdep_assert_held(&prepare_lock);
-
-	hlist_for_each_entry(child, &core->children, child_node)
-		clk_disable_unused_subtree(child);
-
-	flags = clk_enable_lock();
-
-	if (core->enable_count)
-		goto unlock_out;
-
-	if (core->flags & CLK_IGNORE_UNUSED)
-		goto unlock_out;
-
-	/*
-	 * some gate clocks have special needs during the disable-unused
-	 * sequence.  call .disable_unused if available, otherwise fall
-	 * back to .disable
-	 */
-	if (clk_core_is_enabled(core)) {
-		trace_clk_disable(core);
-		if (core->ops->disable_unused)
-			core->ops->disable_unused(core->hw);
-		else if (core->ops->disable)
-			core->ops->disable(core->hw);
-		trace_clk_disable_complete(core);
-	}
-
-unlock_out:
-	clk_enable_unlock(flags);
-}
-
-static bool clk_ignore_unused;
-static int __init clk_ignore_unused_setup(char *__unused)
-{
-	clk_ignore_unused = true;
-	return 1;
-}
-__setup("clk_ignore_unused", clk_ignore_unused_setup);
-
-static int clk_disable_unused(void)
-{
-	struct clk_core *core;
-
-	if (clk_ignore_unused) {
-		pr_warn("clk: Not disabling unused clocks\n");
-		return 0;
-	}
-
-	clk_prepare_lock();
-
-	hlist_for_each_entry(core, &clk_root_list, child_node)
-		clk_disable_unused_subtree(core);
-
-	hlist_for_each_entry(core, &clk_orphan_list, child_node)
-		clk_disable_unused_subtree(core);
-
-	hlist_for_each_entry(core, &clk_root_list, child_node)
-		clk_unprepare_unused_subtree(core);
-
-	hlist_for_each_entry(core, &clk_orphan_list, child_node)
-		clk_unprepare_unused_subtree(core);
-
-	clk_prepare_unlock();
-
-	return 0;
-}
-late_initcall_sync(clk_disable_unused);
-
 /***    helper functions   ***/
 
 const char *__clk_get_name(const struct clk *clk)
@@ -591,6 +493,13 @@ static void clk_core_unprepare(struct clk_core *core)
 	clk_core_unprepare(core->parent);
 }
 
+static void clk_core_unprepare_lock(struct clk_core *core)
+{
+	clk_prepare_lock();
+	clk_core_unprepare(core);
+	clk_prepare_unlock();
+}
+
 /**
  * clk_unprepare - undo preparation of a clock source
  * @clk: the clk being unprepared
@@ -607,9 +516,7 @@ void clk_unprepare(struct clk *clk)
 	if (IS_ERR_OR_NULL(clk))
 		return;
 
-	clk_prepare_lock();
-	clk_core_unprepare(clk->core);
-	clk_prepare_unlock();
+	clk_core_unprepare_lock(clk->core);
 }
 EXPORT_SYMBOL_GPL(clk_unprepare);
 
@@ -645,6 +552,17 @@ static int clk_core_prepare(struct clk_core *core)
 	return 0;
 }
 
+static int clk_core_prepare_lock(struct clk_core *core)
+{
+	int ret;
+
+	clk_prepare_lock();
+	ret = clk_core_prepare(core);
+	clk_prepare_unlock();
+
+	return ret;
+}
+
 /**
  * clk_prepare - prepare a clock source
  * @clk: the clk being prepared
@@ -659,16 +577,10 @@ static int clk_core_prepare(struct clk_core *core)
  */
 int clk_prepare(struct clk *clk)
 {
-	int ret;
-
 	if (!clk)
 		return 0;
 
-	clk_prepare_lock();
-	ret = clk_core_prepare(clk->core);
-	clk_prepare_unlock();
-
-	return ret;
+	return clk_core_prepare_lock(clk->core);
 }
 EXPORT_SYMBOL_GPL(clk_prepare);
 
@@ -688,16 +600,25 @@ static void clk_core_disable(struct clk_core *core)
 	if (--core->enable_count > 0)
 		return;
 
-	trace_clk_disable(core);
+	trace_clk_disable_rcuidle(core);
 
 	if (core->ops->disable)
 		core->ops->disable(core->hw);
 
-	trace_clk_disable_complete(core);
+	trace_clk_disable_complete_rcuidle(core);
 
 	clk_core_disable(core->parent);
 }
 
+static void clk_core_disable_lock(struct clk_core *core)
+{
+	unsigned long flags;
+
+	flags = clk_enable_lock();
+	clk_core_disable(core);
+	clk_enable_unlock(flags);
+}
+
 /**
  * clk_disable - gate a clock
  * @clk: the clk being gated
@@ -712,14 +633,10 @@ static void clk_core_disable(struct clk_core *core)
  */
 void clk_disable(struct clk *clk)
 {
-	unsigned long flags;
-
 	if (IS_ERR_OR_NULL(clk))
 		return;
 
-	flags = clk_enable_lock();
-	clk_core_disable(clk->core);
-	clk_enable_unlock(flags);
+	clk_core_disable_lock(clk->core);
 }
 EXPORT_SYMBOL_GPL(clk_disable);
 
@@ -741,12 +658,12 @@ static int clk_core_enable(struct clk_core *core)
 		if (ret)
 			return ret;
 
-		trace_clk_enable(core);
+		trace_clk_enable_rcuidle(core);
 
 		if (core->ops->enable)
 			ret = core->ops->enable(core->hw);
 
-		trace_clk_enable_complete(core);
+		trace_clk_enable_complete_rcuidle(core);
 
 		if (ret) {
 			clk_core_disable(core->parent);
@@ -758,6 +675,18 @@ static int clk_core_enable(struct clk_core *core)
 	return 0;
 }
 
+static int clk_core_enable_lock(struct clk_core *core)
+{
+	unsigned long flags;
+	int ret;
+
+	flags = clk_enable_lock();
+	ret = clk_core_enable(core);
+	clk_enable_unlock(flags);
+
+	return ret;
+}
+
 /**
  * clk_enable - ungate a clock
  * @clk: the clk being ungated
@@ -773,19 +702,136 @@ static int clk_core_enable(struct clk_core *core)
  */
 int clk_enable(struct clk *clk)
 {
-	unsigned long flags;
-	int ret;
-
 	if (!clk)
 		return 0;
 
+	return clk_core_enable_lock(clk->core);
+}
+EXPORT_SYMBOL_GPL(clk_enable);
+
+static int clk_core_prepare_enable(struct clk_core *core)
+{
+	int ret;
+
+	ret = clk_core_prepare_lock(core);
+	if (ret)
+		return ret;
+
+	ret = clk_core_enable_lock(core);
+	if (ret)
+		clk_core_unprepare_lock(core);
+
+	return ret;
+}
+
+static void clk_core_disable_unprepare(struct clk_core *core)
+{
+	clk_core_disable_lock(core);
+	clk_core_unprepare_lock(core);
+}
+
+static void clk_unprepare_unused_subtree(struct clk_core *core)
+{
+	struct clk_core *child;
+
+	lockdep_assert_held(&prepare_lock);
+
+	hlist_for_each_entry(child, &core->children, child_node)
+		clk_unprepare_unused_subtree(child);
+
+	if (core->prepare_count)
+		return;
+
+	if (core->flags & CLK_IGNORE_UNUSED)
+		return;
+
+	if (clk_core_is_prepared(core)) {
+		trace_clk_unprepare(core);
+		if (core->ops->unprepare_unused)
+			core->ops->unprepare_unused(core->hw);
+		else if (core->ops->unprepare)
+			core->ops->unprepare(core->hw);
+		trace_clk_unprepare_complete(core);
+	}
+}
+
+static void clk_disable_unused_subtree(struct clk_core *core)
+{
+	struct clk_core *child;
+	unsigned long flags;
+
+	lockdep_assert_held(&prepare_lock);
+
+	hlist_for_each_entry(child, &core->children, child_node)
+		clk_disable_unused_subtree(child);
+
+	if (core->flags & CLK_OPS_PARENT_ENABLE)
+		clk_core_prepare_enable(core->parent);
+
 	flags = clk_enable_lock();
-	ret = clk_core_enable(clk->core);
+
+	if (core->enable_count)
+		goto unlock_out;
+
+	if (core->flags & CLK_IGNORE_UNUSED)
+		goto unlock_out;
+
+	/*
+	 * some gate clocks have special needs during the disable-unused
+	 * sequence.  call .disable_unused if available, otherwise fall
+	 * back to .disable
+	 */
+	if (clk_core_is_enabled(core)) {
+		trace_clk_disable(core);
+		if (core->ops->disable_unused)
+			core->ops->disable_unused(core->hw);
+		else if (core->ops->disable)
+			core->ops->disable(core->hw);
+		trace_clk_disable_complete(core);
+	}
+
+unlock_out:
 	clk_enable_unlock(flags);
+	if (core->flags & CLK_OPS_PARENT_ENABLE)
+		clk_core_disable_unprepare(core->parent);
+}
 
-	return ret;
+static bool clk_ignore_unused;
+static int __init clk_ignore_unused_setup(char *__unused)
+{
+	clk_ignore_unused = true;
+	return 1;
 }
-EXPORT_SYMBOL_GPL(clk_enable);
+__setup("clk_ignore_unused", clk_ignore_unused_setup);
+
+static int clk_disable_unused(void)
+{
+	struct clk_core *core;
+
+	if (clk_ignore_unused) {
+		pr_warn("clk: Not disabling unused clocks\n");
+		return 0;
+	}
+
+	clk_prepare_lock();
+
+	hlist_for_each_entry(core, &clk_root_list, child_node)
+		clk_disable_unused_subtree(core);
+
+	hlist_for_each_entry(core, &clk_orphan_list, child_node)
+		clk_disable_unused_subtree(core);
+
+	hlist_for_each_entry(core, &clk_root_list, child_node)
+		clk_unprepare_unused_subtree(core);
+
+	hlist_for_each_entry(core, &clk_orphan_list, child_node)
+		clk_unprepare_unused_subtree(core);
+
+	clk_prepare_unlock();
+
+	return 0;
+}
+late_initcall_sync(clk_disable_unused);
 
 static int clk_core_round_rate_nolock(struct clk_core *core,
 				      struct clk_rate_request *req)
@@ -828,9 +874,7 @@ static int clk_core_round_rate_nolock(struct clk_core *core,
 /**
  * __clk_determine_rate - get the closest rate actually supported by a clock
  * @hw: determine the rate of this clock
- * @rate: target rate
- * @min_rate: returned rate must be greater than this rate
- * @max_rate: returned rate must be less than this rate
+ * @req: target rate request
  *
  * Useful for clk_ops such as .set_rate and .determine_rate.
  */
@@ -1128,7 +1172,9 @@ static struct clk_core *__clk_set_parent_before(struct clk_core *core,
 	struct clk_core *old_parent = core->parent;
 
 	/*
-	 * Migrate prepare state between parents and prevent race with
+	 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
+	 *
+	 * 2. Migrate prepare state between parents and prevent race with
 	 * clk_enable().
 	 *
 	 * If the clock is not prepared, then a race with
@@ -1144,12 +1190,17 @@ static struct clk_core *__clk_set_parent_before(struct clk_core *core,
 	 *
 	 * See also: Comment for clk_set_parent() below.
 	 */
+
+	/* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
+	if (core->flags & CLK_OPS_PARENT_ENABLE) {
+		clk_core_prepare_enable(old_parent);
+		clk_core_prepare_enable(parent);
+	}
+
+	/* migrate prepare count if > 0 */
 	if (core->prepare_count) {
-		clk_core_prepare(parent);
-		flags = clk_enable_lock();
-		clk_core_enable(parent);
-		clk_core_enable(core);
-		clk_enable_unlock(flags);
+		clk_core_prepare_enable(parent);
+		clk_core_enable_lock(core);
 	}
 
 	/* update the clk tree topology */
@@ -1164,18 +1215,19 @@ static void __clk_set_parent_after(struct clk_core *core,
 				   struct clk_core *parent,
 				   struct clk_core *old_parent)
 {
-	unsigned long flags;
-
 	/*
 	 * Finish the migration of prepare state and undo the changes done
 	 * for preventing a race with clk_enable().
 	 */
 	if (core->prepare_count) {
-		flags = clk_enable_lock();
-		clk_core_disable(core);
-		clk_core_disable(old_parent);
-		clk_enable_unlock(flags);
-		clk_core_unprepare(old_parent);
+		clk_core_disable_lock(core);
+		clk_core_disable_unprepare(old_parent);
+	}
+
+	/* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
+	if (core->flags & CLK_OPS_PARENT_ENABLE) {
+		clk_core_disable_unprepare(parent);
+		clk_core_disable_unprepare(old_parent);
 	}
 }
 
@@ -1422,13 +1474,17 @@ static void clk_change_rate(struct clk_core *core)
 	unsigned long best_parent_rate = 0;
 	bool skip_set_rate = false;
 	struct clk_core *old_parent;
+	struct clk_core *parent = NULL;
 
 	old_rate = core->rate;
 
-	if (core->new_parent)
+	if (core->new_parent) {
+		parent = core->new_parent;
 		best_parent_rate = core->new_parent->rate;
-	else if (core->parent)
+	} else if (core->parent) {
+		parent = core->parent;
 		best_parent_rate = core->parent->rate;
+	}
 
 	if (core->flags & CLK_SET_RATE_UNGATE) {
 		unsigned long flags;
@@ -1456,6 +1512,9 @@ static void clk_change_rate(struct clk_core *core)
 		__clk_set_parent_after(core, core->new_parent, old_parent);
 	}
 
+	if (core->flags & CLK_OPS_PARENT_ENABLE)
+		clk_core_prepare_enable(parent);
+
 	trace_clk_set_rate(core, core->new_rate);
 
 	if (!skip_set_rate && core->ops->set_rate)
@@ -1474,6 +1533,9 @@ static void clk_change_rate(struct clk_core *core)
 		clk_core_unprepare(core);
 	}
 
+	if (core->flags & CLK_OPS_PARENT_ENABLE)
+		clk_core_disable_unprepare(parent);
+
 	if (core->notifier_count && old_rate != core->rate)
 		__clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
 
@@ -1501,7 +1563,6 @@ static int clk_core_set_rate_nolock(struct clk_core *core,
 {
 	struct clk_core *top, *fail_clk;
 	unsigned long rate = req_rate;
-	int ret = 0;
 
 	if (!core)
 		return 0;
@@ -1532,7 +1593,7 @@ static int clk_core_set_rate_nolock(struct clk_core *core,
 
 	core->req_rate = req_rate;
 
-	return ret;
+	return 0;
 }
 
 /**