1 files changed, 530 insertions, 147 deletions

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index a004769528e..8b73edef151 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -21,6 +21,8 @@
 #include <linux/init.h>
 #include <linux/sched.h>
 
+#include "clk.h"
+
 static DEFINE_SPINLOCK(enable_lock);
 static DEFINE_MUTEX(prepare_lock);
 
@@ -92,7 +94,7 @@ static void clk_enable_unlock(unsigned long flags)
 
 /***        debugfs support        ***/
 
-#ifdef CONFIG_COMMON_CLK_DEBUG
+#ifdef CONFIG_DEBUG_FS
 #include <linux/debugfs.h>
 
 static struct dentry *rootdir;
@@ -104,11 +106,11 @@ static void clk_summary_show_one(struct seq_file *s, struct clk *c, int level)
 	if (!c)
 		return;
 
-	seq_printf(s, "%*s%-*s %-11d %-12d %-10lu",
+	seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu\n",
 		   level * 3 + 1, "",
 		   30 - level * 3, c->name,
-		   c->enable_count, c->prepare_count, clk_get_rate(c));
-	seq_printf(s, "\n");
+		   c->enable_count, c->prepare_count, clk_get_rate(c),
+		   clk_get_accuracy(c));
 }
 
 static void clk_summary_show_subtree(struct seq_file *s, struct clk *c,
@@ -129,8 +131,8 @@ static int clk_summary_show(struct seq_file *s, void *data)
 {
 	struct clk *c;
 
-	seq_printf(s, "   clock                        enable_cnt  prepare_cnt  rate\n");
-	seq_printf(s, "---------------------------------------------------------------------\n");
+	seq_puts(s, "   clock                         enable_cnt  prepare_cnt        rate   accuracy\n");
+	seq_puts(s, "--------------------------------------------------------------------------------\n");
 
 	clk_prepare_lock();
 
@@ -167,6 +169,7 @@ static void clk_dump_one(struct seq_file *s, struct clk *c, int level)
 	seq_printf(s, "\"enable_count\": %d,", c->enable_count);
 	seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
 	seq_printf(s, "\"rate\": %lu", clk_get_rate(c));
+	seq_printf(s, "\"accuracy\": %lu", clk_get_accuracy(c));
 }
 
 static void clk_dump_subtree(struct seq_file *s, struct clk *c, int level)
@@ -248,6 +251,11 @@ static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry)
 	if (!d)
 		goto err_out;
 
+	d = debugfs_create_u32("clk_accuracy", S_IRUGO, clk->dentry,
+			(u32 *)&clk->accuracy);
+	if (!d)
+		goto err_out;
+
 	d = debugfs_create_x32("clk_flags", S_IRUGO, clk->dentry,
 			(u32 *)&clk->flags);
 	if (!d)
@@ -268,11 +276,16 @@ static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry)
 	if (!d)
 		goto err_out;
 
+	if (clk->ops->debug_init)
+		if (clk->ops->debug_init(clk->hw, clk->dentry))
+			goto err_out;
+
 	ret = 0;
 	goto out;
 
 err_out:
-	debugfs_remove(clk->dentry);
+	debugfs_remove_recursive(clk->dentry);
+	clk->dentry = NULL;
 out:
 	return ret;
 }
@@ -342,6 +355,21 @@ out:
 	return ret;
 }
 
+ /**
+ * clk_debug_unregister - remove a clk node from the debugfs clk tree
+ * @clk: the clk being removed from the debugfs clk tree
+ *
+ * Dynamically removes a clk and all it's children clk nodes from the
+ * debugfs clk tree if clk->dentry points to debugfs created by
+ * clk_debug_register in __clk_init.
+ *
+ * Caller must hold prepare_lock.
+ */
+static void clk_debug_unregister(struct clk *clk)
+{
+	debugfs_remove_recursive(clk->dentry);
+}
+
 /**
  * clk_debug_reparent - reparent clk node in the debugfs clk tree
  * @clk: the clk being reparented
@@ -432,6 +460,9 @@ static inline int clk_debug_register(struct clk *clk) { return 0; }
 static inline void clk_debug_reparent(struct clk *clk, struct clk *new_parent)
 {
 }
+static inline void clk_debug_unregister(struct clk *clk)
+{
+}
 #endif
 
 /* caller must hold prepare_lock */
@@ -547,16 +578,19 @@ struct clk_hw *__clk_get_hw(struct clk *clk)
 {
 	return !clk ? NULL : clk->hw;
 }
+EXPORT_SYMBOL_GPL(__clk_get_hw);
 
 u8 __clk_get_num_parents(struct clk *clk)
 {
 	return !clk ? 0 : clk->num_parents;
 }
+EXPORT_SYMBOL_GPL(__clk_get_num_parents);
 
 struct clk *__clk_get_parent(struct clk *clk)
 {
 	return !clk ? NULL : clk->parent;
 }
+EXPORT_SYMBOL_GPL(__clk_get_parent);
 
 struct clk *clk_get_parent_by_index(struct clk *clk, u8 index)
 {
@@ -570,6 +604,7 @@ struct clk *clk_get_parent_by_index(struct clk *clk, u8 index)
 	else
 		return clk->parents[index];
 }
+EXPORT_SYMBOL_GPL(clk_get_parent_by_index);
 
 unsigned int __clk_get_enable_count(struct clk *clk)
 {
@@ -601,6 +636,15 @@ unsigned long __clk_get_rate(struct clk *clk)
 out:
 	return ret;
 }
+EXPORT_SYMBOL_GPL(__clk_get_rate);
+
+unsigned long __clk_get_accuracy(struct clk *clk)
+{
+	if (!clk)
+		return 0;
+
+	return clk->accuracy;
+}
 
 unsigned long __clk_get_flags(struct clk *clk)
 {
@@ -649,6 +693,7 @@ bool __clk_is_enabled(struct clk *clk)
 out:
 	return !!ret;
 }
+EXPORT_SYMBOL_GPL(__clk_is_enabled);
 
 static struct clk *__clk_lookup_subtree(const char *name, struct clk *clk)
 {
@@ -740,6 +785,7 @@ out:
 
 	return best;
 }
+EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
 
 /***        clk api        ***/
 
@@ -775,6 +821,9 @@ void __clk_unprepare(struct clk *clk)
  */
 void clk_unprepare(struct clk *clk)
 {
+	if (IS_ERR_OR_NULL(clk))
+		return;
+
 	clk_prepare_lock();
 	__clk_unprepare(clk);
 	clk_prepare_unlock();
@@ -836,9 +885,6 @@ static void __clk_disable(struct clk *clk)
 	if (!clk)
 		return;
 
-	if (WARN_ON(IS_ERR(clk)))
-		return;
-
 	if (WARN_ON(clk->enable_count == 0))
 		return;
 
@@ -867,6 +913,9 @@ void clk_disable(struct clk *clk)
 {
 	unsigned long flags;
 
+	if (IS_ERR_OR_NULL(clk))
+		return;
+
 	flags = clk_enable_lock();
 	__clk_disable(clk);
 	clk_enable_unlock(flags);
@@ -957,6 +1006,7 @@ unsigned long __clk_round_rate(struct clk *clk, unsigned long rate)
 	else
 		return clk->rate;
 }
+EXPORT_SYMBOL_GPL(__clk_round_rate);
 
 /**
  * clk_round_rate - round the given rate for a clk
@@ -1016,6 +1066,66 @@ static int __clk_notify(struct clk *clk, unsigned long msg,
 }
 
 /**
+ * __clk_recalc_accuracies
+ * @clk: first clk in the subtree
+ *
+ * Walks the subtree of clks starting with clk and recalculates accuracies as
+ * it goes.  Note that if a clk does not implement the .recalc_accuracy
+ * callback then it is assumed that the clock will take on the accuracy of it's
+ * parent.
+ *
+ * Caller must hold prepare_lock.
+ */
+static void __clk_recalc_accuracies(struct clk *clk)
+{
+	unsigned long parent_accuracy = 0;
+	struct clk *child;
+
+	if (clk->parent)
+		parent_accuracy = clk->parent->accuracy;
+
+	if (clk->ops->recalc_accuracy)
+		clk->accuracy = clk->ops->recalc_accuracy(clk->hw,
+							  parent_accuracy);
+	else
+		clk->accuracy = parent_accuracy;
+
+	hlist_for_each_entry(child, &clk->children, child_node)
+		__clk_recalc_accuracies(child);
+}
+
+/**
+ * clk_get_accuracy - return the accuracy of clk
+ * @clk: the clk whose accuracy is being returned
+ *
+ * Simply returns the cached accuracy of the clk, unless
+ * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
+ * issued.
+ * If clk is NULL then returns 0.
+ */
+long clk_get_accuracy(struct clk *clk)
+{
+	unsigned long accuracy;
+
+	clk_prepare_lock();
+	if (clk && (clk->flags & CLK_GET_ACCURACY_NOCACHE))
+		__clk_recalc_accuracies(clk);
+
+	accuracy = __clk_get_accuracy(clk);
+	clk_prepare_unlock();
+
+	return accuracy;
+}
+EXPORT_SYMBOL_GPL(clk_get_accuracy);
+
+static unsigned long clk_recalc(struct clk *clk, unsigned long parent_rate)
+{
+	if (clk->ops->recalc_rate)
+		return clk->ops->recalc_rate(clk->hw, parent_rate);
+	return parent_rate;
+}
+
+/**
  * __clk_recalc_rates
  * @clk: first clk in the subtree
  * @msg: notification type (see include/linux/clk.h)
@@ -1040,10 +1150,7 @@ static void __clk_recalc_rates(struct clk *clk, unsigned long msg)
 	if (clk->parent)
 		parent_rate = clk->parent->rate;
 
-	if (clk->ops->recalc_rate)
-		clk->rate = clk->ops->recalc_rate(clk->hw, parent_rate);
-	else
-		clk->rate = parent_rate;
+	clk->rate = clk_recalc(clk, parent_rate);
 
 	/*
 	 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
@@ -1080,13 +1187,16 @@ unsigned long clk_get_rate(struct clk *clk)
 }
 EXPORT_SYMBOL_GPL(clk_get_rate);
 
-static u8 clk_fetch_parent_index(struct clk *clk, struct clk *parent)
+static int clk_fetch_parent_index(struct clk *clk, struct clk *parent)
 {
-	u8 i;
+	int i;
 
-	if (!clk->parents)
-		clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents),
-								GFP_KERNEL);
+	if (!clk->parents) {
+		clk->parents = kcalloc(clk->num_parents,
+					sizeof(struct clk *), GFP_KERNEL);
+		if (!clk->parents)
+			return -ENOMEM;
+	}
 
 	/*
 	 * find index of new parent clock using cached parent ptrs,
@@ -1094,16 +1204,19 @@ static u8 clk_fetch_parent_index(struct clk *clk, struct clk *parent)
 	 * them now to avoid future calls to __clk_lookup.
 	 */
 	for (i = 0; i < clk->num_parents; i++) {
-		if (clk->parents && clk->parents[i] == parent)
-			break;
-		else if (!strcmp(clk->parent_names[i], parent->name)) {
-			if (clk->parents)
-				clk->parents[i] = __clk_lookup(parent->name);
-			break;
+		if (clk->parents[i] == parent)
+			return i;
+
+		if (clk->parents[i])
+			continue;
+
+		if (!strcmp(clk->parent_names[i], parent->name)) {
+			clk->parents[i] = __clk_lookup(parent->name);
+			return i;
 		}
 	}
 
-	return i;
+	return -EINVAL;
 }
 
 static void clk_reparent(struct clk *clk, struct clk *new_parent)
@@ -1123,10 +1236,9 @@ static void clk_reparent(struct clk *clk, struct clk *new_parent)
 	clk->parent = new_parent;
 }
 
-static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index)
+static struct clk *__clk_set_parent_before(struct clk *clk, struct clk *parent)
 {
 	unsigned long flags;
-	int ret = 0;
 	struct clk *old_parent = clk->parent;
 
 	/*
@@ -1157,6 +1269,34 @@ static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index)
 	clk_reparent(clk, parent);
 	clk_enable_unlock(flags);
 
+	return old_parent;
+}
+
+static void __clk_set_parent_after(struct clk *clk, struct clk *parent,
+		struct clk *old_parent)
+{
+	/*
+	 * Finish the migration of prepare state and undo the changes done
+	 * for preventing a race with clk_enable().
+	 */
+	if (clk->prepare_count) {
+		clk_disable(clk);
+		clk_disable(old_parent);
+		__clk_unprepare(old_parent);
+	}
+
+	/* update debugfs with new clk tree topology */
+	clk_debug_reparent(clk, parent);
+}
+
+static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index)
+{
+	unsigned long flags;
+	int ret = 0;
+	struct clk *old_parent;
+
+	old_parent = __clk_set_parent_before(clk, parent);
+
 	/* change clock input source */
 	if (parent && clk->ops->set_parent)
 		ret = clk->ops->set_parent(clk->hw, p_index);
@@ -1174,18 +1314,8 @@ static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index)
 		return ret;
 	}
 
-	/*
-	 * Finish the migration of prepare state and undo the changes done
-	 * for preventing a race with clk_enable().
-	 */
-	if (clk->prepare_count) {
-		clk_disable(clk);
-		clk_disable(old_parent);
-		__clk_unprepare(old_parent);
-	}
+	__clk_set_parent_after(clk, parent, old_parent);
 
-	/* update debugfs with new clk tree topology */
-	clk_debug_reparent(clk, parent);
 	return 0;
 }
 
@@ -1211,17 +1341,17 @@ static int __clk_speculate_rates(struct clk *clk, unsigned long parent_rate)
 	unsigned long new_rate;
 	int ret = NOTIFY_DONE;
 
-	if (clk->ops->recalc_rate)
-		new_rate = clk->ops->recalc_rate(clk->hw, parent_rate);
-	else
-		new_rate = parent_rate;
+	new_rate = clk_recalc(clk, parent_rate);
 
 	/* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
 	if (clk->notifier_count)
 		ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate);
 
-	if (ret & NOTIFY_STOP_MASK)
+	if (ret & NOTIFY_STOP_MASK) {
+		pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
+				__func__, clk->name, ret);
 		goto out;
+	}
 
 	hlist_for_each_entry(child, &clk->children, child_node) {
 		ret = __clk_speculate_rates(child, new_rate);
@@ -1247,10 +1377,7 @@ static void clk_calc_subtree(struct clk *clk, unsigned long new_rate,
 		new_parent->new_child = clk;
 
 	hlist_for_each_entry(child, &clk->children, child_node) {
-		if (child->ops->recalc_rate)
-			child->new_rate = child->ops->recalc_rate(child->hw, new_rate);
-		else
-			child->new_rate = new_rate;
+		child->new_rate = clk_recalc(child, new_rate);
 		clk_calc_subtree(child, child->new_rate, NULL, 0);
 	}
 }
@@ -1265,7 +1392,7 @@ static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate)
 	struct clk *old_parent, *parent;
 	unsigned long best_parent_rate = 0;
 	unsigned long new_rate;
-	u8 p_index = 0;
+	int p_index = 0;
 
 	/* sanity */
 	if (IS_ERR_OR_NULL(clk))
@@ -1306,7 +1433,7 @@ static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate)
 	/* try finding the new parent index */
 	if (parent) {
 		p_index = clk_fetch_parent_index(clk, parent);
-		if (p_index == clk->num_parents) {
+		if (p_index < 0) {
 			pr_debug("%s: clk %s can not be parent of clk %s\n",
 				 __func__, parent->name, clk->name);
 			return NULL;
@@ -1370,23 +1497,35 @@ static void clk_change_rate(struct clk *clk)
 	struct clk *child;
 	unsigned long old_rate;
 	unsigned long best_parent_rate = 0;
+	bool skip_set_rate = false;
+	struct clk *old_parent;
 
 	old_rate = clk->rate;
 
-	/* set parent */
-	if (clk->new_parent && clk->new_parent != clk->parent)
-		__clk_set_parent(clk, clk->new_parent, clk->new_parent_index);
-
-	if (clk->parent)
+	if (clk->new_parent)
+		best_parent_rate = clk->new_parent->rate;
+	else if (clk->parent)
 		best_parent_rate = clk->parent->rate;
 
-	if (clk->ops->set_rate)
+	if (clk->new_parent && clk->new_parent != clk->parent) {
+		old_parent = __clk_set_parent_before(clk, clk->new_parent);
+
+		if (clk->ops->set_rate_and_parent) {
+			skip_set_rate = true;
+			clk->ops->set_rate_and_parent(clk->hw, clk->new_rate,
+					best_parent_rate,
+					clk->new_parent_index);
+		} else if (clk->ops->set_parent) {
+			clk->ops->set_parent(clk->hw, clk->new_parent_index);
+		}
+
+		__clk_set_parent_after(clk, clk->new_parent, old_parent);
+	}
+
+	if (!skip_set_rate && clk->ops->set_rate)
 		clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate);
 
-	if (clk->ops->recalc_rate)
-		clk->rate = clk->ops->recalc_rate(clk->hw, best_parent_rate);
-	else
-		clk->rate = best_parent_rate;
+	clk->rate = clk_recalc(clk, best_parent_rate);
 
 	if (clk->notifier_count && old_rate != clk->rate)
 		__clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate);
@@ -1454,7 +1593,7 @@ int clk_set_rate(struct clk *clk, unsigned long rate)
 	/* notify that we are about to change rates */
 	fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
 	if (fail_clk) {
-		pr_warn("%s: failed to set %s rate\n", __func__,
+		pr_debug("%s: failed to set %s rate\n", __func__,
 				fail_clk->name);
 		clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
 		ret = -EBUSY;
@@ -1532,7 +1671,7 @@ static struct clk *__clk_init_parent(struct clk *clk)
 
 	if (!clk->parents)
 		clk->parents =
-			kzalloc((sizeof(struct clk*) * clk->num_parents),
+			kcalloc(clk->num_parents, sizeof(struct clk *),
 					GFP_KERNEL);
 
 	ret = clk_get_parent_by_index(clk, index);
@@ -1545,6 +1684,7 @@ void __clk_reparent(struct clk *clk, struct clk *new_parent)
 {
 	clk_reparent(clk, new_parent);
 	clk_debug_reparent(clk, new_parent);
+	__clk_recalc_accuracies(clk);
 	__clk_recalc_rates(clk, POST_RATE_CHANGE);
 }
 
@@ -1568,15 +1708,12 @@ void __clk_reparent(struct clk *clk, struct clk *new_parent)
 int clk_set_parent(struct clk *clk, struct clk *parent)
 {
 	int ret = 0;
-	u8 p_index = 0;
+	int p_index = 0;
 	unsigned long p_rate = 0;
 
 	if (!clk)
 		return 0;
 
-	if (!clk->ops)
-		return -EINVAL;
-
 	/* verify ops for for multi-parent clks */
 	if ((clk->num_parents > 1) && (!clk->ops->set_parent))
 		return -ENOSYS;
@@ -1597,10 +1734,10 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
 	if (parent) {
 		p_index = clk_fetch_parent_index(clk, parent);
 		p_rate = parent->rate;
-		if (p_index == clk->num_parents) {
+		if (p_index < 0) {
 			pr_debug("%s: clk %s can not be parent of clk %s\n",
 					__func__, parent->name, clk->name);
-			ret = -EINVAL;
+			ret = p_index;
 			goto out;
 		}
 	}
@@ -1615,11 +1752,13 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
 	/* do the re-parent */
 	ret = __clk_set_parent(clk, parent, p_index);
 
-	/* propagate rate recalculation accordingly */
-	if (ret)
+	/* propagate rate an accuracy recalculation accordingly */
+	if (ret) {
 		__clk_recalc_rates(clk, ABORT_RATE_CHANGE);
-	else
+	} else {
 		__clk_recalc_rates(clk, POST_RATE_CHANGE);
+		__clk_recalc_accuracies(clk);
+	}
 
 out:
 	clk_prepare_unlock();
@@ -1672,6 +1811,14 @@ int __clk_init(struct device *dev, struct clk *clk)
 		goto out;
 	}
 
+	if (clk->ops->set_rate_and_parent &&
+			!(clk->ops->set_parent && clk->ops->set_rate)) {
+		pr_warn("%s: %s must implement .set_parent & .set_rate\n",
+				__func__, clk->name);
+		ret = -EINVAL;
+		goto out;
+	}
+
 	/* throw a WARN if any entries in parent_names are NULL */
 	for (i = 0; i < clk->num_parents; i++)
 		WARN(!clk->parent_names[i],
@@ -1689,8 +1836,8 @@ int __clk_init(struct device *dev, struct clk *clk)
 	 * for clock drivers to statically initialize clk->parents.
 	 */
 	if (clk->num_parents > 1 && !clk->parents) {
-		clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents),
-				GFP_KERNEL);
+		clk->parents = kcalloc(clk->num_parents, sizeof(struct clk *),
+					GFP_KERNEL);
 		/*
 		 * __clk_lookup returns NULL for parents that have not been
 		 * clk_init'd; thus any access to clk->parents[] must check
@@ -1724,6 +1871,21 @@ int __clk_init(struct device *dev, struct clk *clk)
 		hlist_add_head(&clk->child_node, &clk_orphan_list);
 
 	/*
+	 * Set clk's accuracy.  The preferred method is to use
+	 * .recalc_accuracy. For simple clocks and lazy developers the default
+	 * fallback is to use the parent's accuracy.  If a clock doesn't have a
+	 * parent (or is orphaned) then accuracy is set to zero (perfect
+	 * clock).
+	 */
+	if (clk->ops->recalc_accuracy)
+		clk->accuracy = clk->ops->recalc_accuracy(clk->hw,
+					__clk_get_accuracy(clk->parent));
+	else if (clk->parent)
+		clk->accuracy = clk->parent->accuracy;
+	else
+		clk->accuracy = 0;
+
+	/*
 	 * Set clk's rate.  The preferred method is to use .recalc_rate.  For
 	 * simple clocks and lazy developers the default fallback is to use the
 	 * parent's rate.  If a clock doesn't have a parent (or is orphaned)
@@ -1737,6 +1899,7 @@ int __clk_init(struct device *dev, struct clk *clk)
 	else
 		clk->rate = 0;
 
+	clk_debug_register(clk);
 	/*
 	 * walk the list of orphan clocks and reparent any that are children of
 	 * this clock
@@ -1767,8 +1930,7 @@ int __clk_init(struct device *dev, struct clk *clk)
 	if (clk->ops->init)
 		clk->ops->init(clk->hw);
 
-	clk_debug_register(clk);
-
+	kref_init(&clk->ref);
 out:
 	clk_prepare_unlock();
 
@@ -1804,6 +1966,10 @@ struct clk *__clk_register(struct device *dev, struct clk_hw *hw)
 	clk->flags = hw->init->flags;
 	clk->parent_names = hw->init->parent_names;
 	clk->num_parents = hw->init->num_parents;
+	if (dev && dev->driver)
+		clk->owner = dev->driver->owner;
+	else
+		clk->owner = NULL;
 
 	ret = __clk_init(dev, clk);
 	if (ret)
@@ -1813,9 +1979,28 @@ struct clk *__clk_register(struct device *dev, struct clk_hw *hw)
 }
 EXPORT_SYMBOL_GPL(__clk_register);
 
-static int _clk_register(struct device *dev, struct clk_hw *hw, struct clk *clk)
+/**
+ * clk_register - allocate a new clock, register it and return an opaque cookie
+ * @dev: device that is registering this clock
+ * @hw: link to hardware-specific clock data
+ *
+ * clk_register is the primary interface for populating the clock tree with new
+ * clock nodes.  It returns a pointer to the newly allocated struct clk which
+ * cannot be dereferenced by driver code but may be used in conjuction with the
+ * rest of the clock API.  In the event of an error clk_register will return an
+ * error code; drivers must test for an error code after calling clk_register.
+ */
+struct clk *clk_register(struct device *dev, struct clk_hw *hw)
 {
 	int i, ret;
+	struct clk *clk;
+
+	clk = kzalloc(sizeof(*clk), GFP_KERNEL);
+	if (!clk) {
+		pr_err("%s: could not allocate clk\n", __func__);
+		ret = -ENOMEM;
+		goto fail_out;
+	}
 
 	clk->name = kstrdup(hw->init->name, GFP_KERNEL);
 	if (!clk->name) {
@@ -1824,14 +2009,16 @@ static int _clk_register(struct device *dev, struct clk_hw *hw, struct clk *clk)
 		goto fail_name;
 	}
 	clk->ops = hw->init->ops;
+	if (dev && dev->driver)
+		clk->owner = dev->driver->owner;
 	clk->hw = hw;
 	clk->flags = hw->init->flags;
 	clk->num_parents = hw->init->num_parents;
 	hw->clk = clk;
 
 	/* allocate local copy in case parent_names is __initdata */
-	clk->parent_names = kzalloc((sizeof(char*) * clk->num_parents),
-			GFP_KERNEL);
+	clk->parent_names = kcalloc(clk->num_parents, sizeof(char *),
+					GFP_KERNEL);
 
 	if (!clk->parent_names) {
 		pr_err("%s: could not allocate clk->parent_names\n", __func__);
@@ -1853,7 +2040,7 @@ static int _clk_register(struct device *dev, struct clk_hw *hw, struct clk *clk)
 
 	ret = __clk_init(dev, clk);
 	if (!ret)
-		return 0;
+		return clk;
 
 fail_parent_names_copy:
 	while (--i >= 0)
@@ -1862,54 +2049,116 @@ fail_parent_names_copy:
 fail_parent_names:
 	kfree(clk->name);
 fail_name:
-	return ret;
+	kfree(clk);
+fail_out:
+	return ERR_PTR(ret);
 }
+EXPORT_SYMBOL_GPL(clk_register);
 
-/**
- * clk_register - allocate a new clock, register it and return an opaque cookie
- * @dev: device that is registering this clock
- * @hw: link to hardware-specific clock data
- *
- * clk_register is the primary interface for populating the clock tree with new
- * clock nodes.  It returns a pointer to the newly allocated struct clk which
- * cannot be dereferenced by driver code but may be used in conjuction with the
- * rest of the clock API.  In the event of an error clk_register will return an
- * error code; drivers must test for an error code after calling clk_register.
+/*
+ * Free memory allocated for a clock.
+ * Caller must hold prepare_lock.
  */
-struct clk *clk_register(struct device *dev, struct clk_hw *hw)
+static void __clk_release(struct kref *ref)
 {
-	int ret;
-	struct clk *clk;
-
-	clk = kzalloc(sizeof(*clk), GFP_KERNEL);
-	if (!clk) {
-		pr_err("%s: could not allocate clk\n", __func__);
-		ret = -ENOMEM;
-		goto fail_out;
-	}
+	struct clk *clk = container_of(ref, struct clk, ref);
+	int i = clk->num_parents;
 
-	ret = _clk_register(dev, hw, clk);
-	if (!ret)
-		return clk;
+	kfree(clk->parents);
+	while (--i >= 0)
+		kfree(clk->parent_names[i]);
 
+	kfree(clk->parent_names);
+	kfree(clk->name);
 	kfree(clk);
-fail_out:
-	return ERR_PTR(ret);
 }
-EXPORT_SYMBOL_GPL(clk_register);
+
+/*
+ * Empty clk_ops for unregistered clocks. These are used temporarily
+ * after clk_unregister() was called on a clock and until last clock
+ * consumer calls clk_put() and the struct clk object is freed.
+ */
+static int clk_nodrv_prepare_enable(struct clk_hw *hw)
+{
+	return -ENXIO;
+}
+
+static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
+{
+	WARN_ON_ONCE(1);
+}
+
+static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
+					unsigned long parent_rate)
+{
+	return -ENXIO;
+}
+
+static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
+{
+	return -ENXIO;
+}
+
+static const struct clk_ops clk_nodrv_ops = {
+	.enable		= clk_nodrv_prepare_enable,
+	.disable	= clk_nodrv_disable_unprepare,
+	.prepare	= clk_nodrv_prepare_enable,
+	.unprepare	= clk_nodrv_disable_unprepare,
+	.set_rate	= clk_nodrv_set_rate,
+	.set_parent	= clk_nodrv_set_parent,
+};
 
 /**
  * clk_unregister - unregister a currently registered clock
  * @clk: clock to unregister
- *
- * Currently unimplemented.
  */
-void clk_unregister(struct clk *clk) {}
+void clk_unregister(struct clk *clk)
+{
+	unsigned long flags;
+
+       if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
+               return;
+
+	clk_prepare_lock();
+
+	if (clk->ops == &clk_nodrv_ops) {
+		pr_err("%s: unregistered clock: %s\n", __func__, clk->name);
+		goto out;
+	}
+	/*
+	 * Assign empty clock ops for consumers that might still hold
+	 * a reference to this clock.
+	 */
+	flags = clk_enable_lock();
+	clk->ops = &clk_nodrv_ops;
+	clk_enable_unlock(flags);
+
+	if (!hlist_empty(&clk->children)) {
+		struct clk *child;
+		struct hlist_node *t;
+
+		/* Reparent all children to the orphan list. */
+		hlist_for_each_entry_safe(child, t, &clk->children, child_node)
+			clk_set_parent(child, NULL);
+	}
+
+	clk_debug_unregister(clk);
+
+	hlist_del_init(&clk->child_node);
+
+	if (clk->prepare_count)
+		pr_warn("%s: unregistering prepared clock: %s\n",
+					__func__, clk->name);
+
+	kref_put(&clk->ref, __clk_release);
+out:
+	clk_prepare_unlock();
+}
 EXPORT_SYMBOL_GPL(clk_unregister);
 
 static void devm_clk_release(struct device *dev, void *res)
 {
-	clk_unregister(res);
+	clk_unregister(*(struct clk **)res);
 }
 
 /**
@@ -1924,18 +2173,18 @@ static void devm_clk_release(struct device *dev, void *res)
 struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
 {
 	struct clk *clk;
-	int ret;
+	struct clk **clkp;
 
-	clk = devres_alloc(devm_clk_release, sizeof(*clk), GFP_KERNEL);
-	if (!clk)
+	clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
+	if (!clkp)
 		return ERR_PTR(-ENOMEM);
 
-	ret = _clk_register(dev, hw, clk);
-	if (!ret) {
-		devres_add(dev, clk);
+	clk = clk_register(dev, hw);
+	if (!IS_ERR(clk)) {
+		*clkp = clk;
+		devres_add(dev, clkp);
 	} else {
-		devres_free(clk);
-		clk = ERR_PTR(ret);
+		devres_free(clkp);
 	}
 
 	return clk;
@@ -1964,6 +2213,32 @@ void devm_clk_unregister(struct device *dev, struct clk *clk)
 }
 EXPORT_SYMBOL_GPL(devm_clk_unregister);
 
+/*
+ * clkdev helpers
+ */
+int __clk_get(struct clk *clk)
+{
+	if (clk) {
+		if (!try_module_get(clk->owner))
+			return 0;
+
+		kref_get(&clk->ref);
+	}
+	return 1;
+}
+
+void __clk_put(struct clk *clk)
+{
+	if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
+		return;
+
+	clk_prepare_lock();
+	kref_put(&clk->ref, __clk_release);
+	clk_prepare_unlock();
+
+	module_put(clk->owner);
+}
+
 /***        clk rate change notifiers        ***/
 
 /**
@@ -1977,20 +2252,11 @@ EXPORT_SYMBOL_GPL(devm_clk_unregister);
  * re-enter into the clk framework by calling any top-level clk APIs;
  * this will cause a nested prepare_lock mutex.
  *
- * Pre-change notifier callbacks will be passed the current, pre-change
- * rate of the clk via struct clk_notifier_data.old_rate.  The new,
- * post-change rate of the clk is passed via struct
- * clk_notifier_data.new_rate.
- *
- * Post-change notifiers will pass the now-current, post-change rate of
- * the clk in both struct clk_notifier_data.old_rate and struct
+ * In all notification cases cases (pre, post and abort rate change) the
+ * original clock rate is passed to the callback via struct
+ * clk_notifier_data.old_rate and the new frequency is passed via struct
  * clk_notifier_data.new_rate.
  *
- * Abort-change notifiers are effectively the opposite of pre-change
- * notifiers: the original pre-change clk rate is passed in via struct
- * clk_notifier_data.new_rate and the failed post-change rate is passed
- * in via struct clk_notifier_data.old_rate.
- *
  * clk_notifier_register() must be called from non-atomic context.
  * Returns -EINVAL if called with null arguments, -ENOMEM upon
  * allocation failure; otherwise, passes along the return value of
@@ -2098,13 +2364,22 @@ struct of_clk_provider {
 	void *data;
 };
 
-extern struct of_device_id __clk_of_table[];
-
 static const struct of_device_id __clk_of_table_sentinel
 	__used __section(__clk_of_table_end);
 
 static LIST_HEAD(of_clk_providers);
-static DEFINE_MUTEX(of_clk_lock);
+static DEFINE_MUTEX(of_clk_mutex);
+
+/* of_clk_provider list locking helpers */
+void of_clk_lock(void)
+{
+	mutex_lock(&of_clk_mutex);
+}
+
+void of_clk_unlock(void)
+{
+	mutex_unlock(&of_clk_mutex);
+}
 
 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
 				     void *data)
@@ -2148,9 +2423,9 @@ int of_clk_add_provider(struct device_node *np,
 	cp->data = data;
 	cp->get = clk_src_get;
 
-	mutex_lock(&of_clk_lock);
+	mutex_lock(&of_clk_mutex);
 	list_add(&cp->link, &of_clk_providers);
-	mutex_unlock(&of_clk_lock);
+	mutex_unlock(&of_clk_mutex);
 	pr_debug("Added clock from %s\n", np->full_name);
 
 	return 0;
@@ -2165,7 +2440,7 @@ void of_clk_del_provider(struct device_node *np)
 {
 	struct of_clk_provider *cp;
 
-	mutex_lock(&of_clk_lock);
+	mutex_lock(&of_clk_mutex);
 	list_for_each_entry(cp, &of_clk_providers, link) {
 		if (cp->node == np) {
 			list_del(&cp->link);
@@ -2174,33 +2449,52 @@ void of_clk_del_provider(struct device_node *np)
 			break;
 		}
 	}
-	mutex_unlock(&of_clk_lock);
+	mutex_unlock(&of_clk_mutex);
 }
 EXPORT_SYMBOL_GPL(of_clk_del_provider);
 
-struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
+struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec)
 {
 	struct of_clk_provider *provider;
-	struct clk *clk = ERR_PTR(-ENOENT);
+	struct clk *clk = ERR_PTR(-EPROBE_DEFER);
 
 	/* Check if we have such a provider in our array */
-	mutex_lock(&of_clk_lock);
 	list_for_each_entry(provider, &of_clk_providers, link) {
 		if (provider->node == clkspec->np)
 			clk = provider->get(clkspec, provider->data);
 		if (!IS_ERR(clk))
 			break;
 	}
-	mutex_unlock(&of_clk_lock);
 
 	return clk;
 }
 
+struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
+{
+	struct clk *clk;
+
+	mutex_lock(&of_clk_mutex);
+	clk = __of_clk_get_from_provider(clkspec);
+	mutex_unlock(&of_clk_mutex);
+
+	return clk;
+}
+
+int of_clk_get_parent_count(struct device_node *np)
+{
+	return of_count_phandle_with_args(np, "clocks", "#clock-cells");
+}
+EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
+
 const char *of_clk_get_parent_name(struct device_node *np, int index)
 {
 	struct of_phandle_args clkspec;
+	struct property *prop;
 	const char *clk_name;
+	const __be32 *vp;
+	u32 pv;
 	int rc;
+	int count;
 
 	if (index < 0)
 		return NULL;
@@ -2210,8 +2504,22 @@ const char *of_clk_get_parent_name(struct device_node *np, int index)
 	if (rc)
 		return NULL;
 
+	index = clkspec.args_count ? clkspec.args[0] : 0;
+	count = 0;
+
+	/* if there is an indices property, use it to transfer the index
+	 * specified into an array offset for the clock-output-names property.
+	 */
+	of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
+		if (index == pv) {
+			index = count;
+			break;
+		}
+		count++;
+	}
+
 	if (of_property_read_string_index(clkspec.np, "clock-output-names",
-					  clkspec.args_count ? clkspec.args[0] : 0,
+					  index,
 					  &clk_name) < 0)
 		clk_name = clkspec.np->name;
 
@@ -2220,24 +2528,99 @@ const char *of_clk_get_parent_name(struct device_node *np, int index)
 }
 EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
 
+struct clock_provider {
+	of_clk_init_cb_t clk_init_cb;
+	struct device_node *np;
+	struct list_head node;
+};
+
+static LIST_HEAD(clk_provider_list);
+
+/*
+ * This function looks for a parent clock. If there is one, then it
+ * checks that the provider for this parent clock was initialized, in
+ * this case the parent clock will be ready.
+ */
+static int parent_ready(struct device_node *np)
+{
+	int i = 0;
+
+	while (true) {
+		struct clk *clk = of_clk_get(np, i);
+
+		/* this parent is ready we can check the next one */
+		if (!IS_ERR(clk)) {
+			clk_put(clk);
+			i++;
+			continue;
+		}
+
+		/* at least one parent is not ready, we exit now */
+		if (PTR_ERR(clk) == -EPROBE_DEFER)
+			return 0;
+
+		/*
+		 * Here we make assumption that the device tree is
+		 * written correctly. So an error means that there is
+		 * no more parent. As we didn't exit yet, then the
+		 * previous parent are ready. If there is no clock
+		 * parent, no need to wait for them, then we can
+		 * consider their absence as being ready
+		 */
+		return 1;
+	}
+}
+
 /**
  * of_clk_init() - Scan and init clock providers from the DT
  * @matches: array of compatible values and init functions for providers.
  *
- * This function scans the device tree for matching clock providers and
- * calls their initialization functions
+ * This function scans the device tree for matching clock providers
+ * and calls their initialization functions. It also does it by trying
+ * to follow the dependencies.
  */
 void __init of_clk_init(const struct of_device_id *matches)
 {
 	const struct of_device_id *match;
 	struct device_node *np;
+	struct clock_provider *clk_provider, *next;
+	bool is_init_done;
+	bool force = false;
 
 	if (!matches)
-		matches = __clk_of_table;
+		matches = &__clk_of_table;
 
+	/* First prepare the list of the clocks providers */
 	for_each_matching_node_and_match(np, matches, &match) {
-		of_clk_init_cb_t clk_init_cb = match->data;
-		clk_init_cb(np);
+		struct clock_provider *parent =
+			kzalloc(sizeof(struct clock_provider),	GFP_KERNEL);
+
+		parent->clk_init_cb = match->data;
+		parent->np = np;
+		list_add_tail(&parent->node, &clk_provider_list);
+	}
+
+	while (!list_empty(&clk_provider_list)) {
+		is_init_done = false;
+		list_for_each_entry_safe(clk_provider, next,
+					&clk_provider_list, node) {
+			if (force || parent_ready(clk_provider->np)) {
+				clk_provider->clk_init_cb(clk_provider->np);
+				list_del(&clk_provider->node);
+				kfree(clk_provider);
+				is_init_done = true;
+			}
+		}
+
+		/*
+		 * We didn't manage to initialize any of the
+		 * remaining providers during the last loop, so now we
+		 * initialize all the remaining ones unconditionally
+		 * in case the clock parent was not mandatory
+		 */
+		if (!is_init_done)
+			force = true;
+
 	}
 }
 #endif