1 files changed, 200 insertions, 62 deletions

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index ffa63ddcd408..ffd33b63c37e 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -39,6 +39,13 @@ static LIST_HEAD(clk_notifier_list);
 
 /***    private data structures    ***/
 
+struct clk_parent_map {
+	const struct clk_hw	*hw;
+	struct clk_core		*core;
+	const char		*fw_name;
+	const char		*name;
+};
+
 struct clk_core {
 	const char		*name;
 	const struct clk_ops	*ops;
@@ -47,8 +54,7 @@ struct clk_core {
 	struct device		*dev;
 	struct device_node	*of_node;
 	struct clk_core		*parent;
-	const char		**parent_names;
-	struct clk_core		**parents;
+	struct clk_parent_map	*parents;
 	u8			num_parents;
 	u8			new_parent_index;
 	unsigned long		rate;
@@ -317,17 +323,92 @@ static struct clk_core *clk_core_lookup(const char *name)
 	return NULL;
 }
 
+/**
+ * clk_core_get - Find the parent of a clk using a clock specifier in DT
+ * @core: clk to find parent of
+ * @name: name to search for in 'clock-names' of device providing clk
+ *
+ * This is the preferred method for clk providers to find the parent of a
+ * clk when that parent is external to the clk controller. The parent_names
+ * array is indexed and treated as a local name matching a string in the device
+ * node's 'clock-names' property. This allows clk providers to use their own
+ * namespace instead of looking for a globally unique parent string.
+ *
+ * For example the following DT snippet would allow a clock registered by the
+ * clock-controller@c001 that has a clk_init_data::parent_data array
+ * with 'xtal' in the 'name' member to find the clock provided by the
+ * clock-controller@f00abcd without needing to get the globally unique name of
+ * the xtal clk.
+ *
+ *      parent: clock-controller@f00abcd {
+ *              reg = <0xf00abcd 0xabcd>;
+ *              #clock-cells = <0>;
+ *      };
+ *
+ *      clock-controller@c001 {
+ *              reg = <0xc001 0xf00d>;
+ *              clocks = <&parent>;
+ *              clock-names = "xtal";
+ *              #clock-cells = <1>;
+ *      };
+ *
+ * Returns: -ENOENT when the provider can't be found or the clk doesn't
+ * exist in the provider. -EINVAL when the name can't be found. NULL when the
+ * provider knows about the clk but it isn't provided on this system.
+ * A valid clk_core pointer when the clk can be found in the provider.
+ */
+static struct clk_core *clk_core_get(struct clk_core *core, const char *name)
+{
+	struct clk_hw *hw;
+	struct device_node *np = core->of_node;
+
+	if (!np)
+		return ERR_PTR(-ENOENT);
+
+	/* TODO: Support clkdev clk_lookups */
+	hw = of_clk_get_hw(np, -1, name);
+	if (IS_ERR_OR_NULL(hw))
+		return ERR_CAST(hw);
+
+	return hw->core;
+}
+
+static void clk_core_fill_parent_index(struct clk_core *core, u8 index)
+{
+	struct clk_parent_map *entry = &core->parents[index];
+	struct clk_core *parent = ERR_PTR(-ENOENT);
+
+	if (entry->hw) {
+		parent = entry->hw->core;
+		/*
+		 * We have a direct reference but it isn't registered yet?
+		 * Orphan it and let clk_reparent() update the orphan status
+		 * when the parent is registered.
+		 */
+		if (!parent)
+			parent = ERR_PTR(-EPROBE_DEFER);
+	} else {
+		if (entry->fw_name)
+			parent = clk_core_get(core, entry->fw_name);
+		if (IS_ERR(parent) && PTR_ERR(parent) == -ENOENT)
+			parent = clk_core_lookup(entry->name);
+	}
+
+	/* Only cache it if it's not an error */
+	if (!IS_ERR(parent))
+		entry->core = parent;
+}
+
 static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
 							 u8 index)
 {
-	if (!core || index >= core->num_parents)
+	if (!core || index >= core->num_parents || !core->parents)
 		return NULL;
 
-	if (!core->parents[index])
-		core->parents[index] =
-				clk_core_lookup(core->parent_names[index]);
+	if (!core->parents[index].core)
+		clk_core_fill_parent_index(core, index);
 
-	return core->parents[index];
+	return core->parents[index].core;
 }
 
 struct clk_hw *
@@ -1520,15 +1601,15 @@ static int clk_fetch_parent_index(struct clk_core *core,
 		return -EINVAL;
 
 	for (i = 0; i < core->num_parents; i++) {
-		if (core->parents[i] == parent)
+		if (core->parents[i].core == parent)
 			return i;
 
-		if (core->parents[i])
+		if (core->parents[i].core)
 			continue;
 
 		/* Fallback to comparing globally unique names */
-		if (!strcmp(parent->name, core->parent_names[i])) {
-			core->parents[i] = parent;
+		if (!strcmp(parent->name, core->parents[i].name)) {
+			core->parents[i].core = parent;
 			return i;
 		}
 	}
@@ -2294,6 +2375,7 @@ void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
 bool clk_has_parent(struct clk *clk, struct clk *parent)
 {
 	struct clk_core *core, *parent_core;
+	int i;
 
 	/* NULL clocks should be nops, so return success if either is NULL. */
 	if (!clk || !parent)
@@ -2306,8 +2388,11 @@ bool clk_has_parent(struct clk *clk, struct clk *parent)
 	if (core->parent == parent_core)
 		return true;
 
-	return match_string(core->parent_names, core->num_parents,
-			    parent_core->name) >= 0;
+	for (i = 0; i < core->num_parents; i++)
+		if (!strcmp(core->parents[i].name, parent_core->name))
+			return true;
+
+	return false;
 }
 EXPORT_SYMBOL_GPL(clk_has_parent);
 
@@ -2890,9 +2975,9 @@ static int possible_parents_show(struct seq_file *s, void *data)
 	int i;
 
 	for (i = 0; i < core->num_parents - 1; i++)
-		seq_printf(s, "%s ", core->parent_names[i]);
+		seq_printf(s, "%s ", core->parents[i].name);
 
-	seq_printf(s, "%s\n", core->parent_names[i]);
+	seq_printf(s, "%s\n", core->parents[i].name);
 
 	return 0;
 }
@@ -3026,7 +3111,7 @@ static inline void clk_debug_unregister(struct clk_core *core)
  */
 static int __clk_core_init(struct clk_core *core)
 {
-	int i, ret;
+	int ret;
 	struct clk_core *orphan;
 	struct hlist_node *tmp2;
 	unsigned long rate;
@@ -3080,12 +3165,6 @@ static int __clk_core_init(struct clk_core *core)
 		goto out;
 	}
 
-	/* throw a WARN if any entries in parent_names are NULL */
-	for (i = 0; i < core->num_parents; i++)
-		WARN(!core->parent_names[i],
-				"%s: invalid NULL in %s's .parent_names\n",
-				__func__, core->name);
-
 	core->parent = __clk_init_parent(core);
 
 	/*
@@ -3314,10 +3393,102 @@ struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
 	return clk;
 }
 
+static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
+{
+	const char *dst;
+
+	if (!src) {
+		if (must_exist)
+			return -EINVAL;
+		return 0;
+	}
+
+	*dst_p = dst = kstrdup_const(src, GFP_KERNEL);
+	if (!dst)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int clk_core_populate_parent_map(struct clk_core *core)
+{
+	const struct clk_init_data *init = core->hw->init;
+	u8 num_parents = init->num_parents;
+	const char * const *parent_names = init->parent_names;
+	const struct clk_hw **parent_hws = init->parent_hws;
+	const struct clk_parent_data *parent_data = init->parent_data;
+	int i, ret = 0;
+	struct clk_parent_map *parents, *parent;
+
+	if (!num_parents)
+		return 0;
+
+	/*
+	 * Avoid unnecessary string look-ups of clk_core's possible parents by
+	 * having a cache of names/clk_hw pointers to clk_core pointers.
+	 */
+	parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
+	core->parents = parents;
+	if (!parents)
+		return -ENOMEM;
+
+	/* Copy everything over because it might be __initdata */
+	for (i = 0, parent = parents; i < num_parents; i++, parent++) {
+		if (parent_names) {
+			/* throw a WARN if any entries are NULL */
+			WARN(!parent_names[i],
+				"%s: invalid NULL in %s's .parent_names\n",
+				__func__, core->name);
+			ret = clk_cpy_name(&parent->name, parent_names[i],
+					   true);
+		} else if (parent_data) {
+			parent->hw = parent_data[i].hw;
+			ret = clk_cpy_name(&parent->fw_name,
+					   parent_data[i].fw_name, false);
+			if (!ret)
+				ret = clk_cpy_name(&parent->name,
+						   parent_data[i].name,
+						   false);
+		} else if (parent_hws) {
+			parent->hw = parent_hws[i];
+		} else {
+			ret = -EINVAL;
+			WARN(1, "Must specify parents if num_parents > 0\n");
+		}
+
+		if (ret) {
+			do {
+				kfree_const(parents[i].name);
+				kfree_const(parents[i].fw_name);
+			} while (--i >= 0);
+			kfree(parents);
+
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void clk_core_free_parent_map(struct clk_core *core)
+{
+	int i = core->num_parents;
+
+	if (!core->num_parents)
+		return;
+
+	while (--i >= 0) {
+		kfree_const(core->parents[i].name);
+		kfree_const(core->parents[i].fw_name);
+	}
+
+	kfree(core->parents);
+}
+
 static struct clk *
 __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
 {
-	int i, ret;
+	int ret;
 	struct clk_core *core;
 
 	core = kzalloc(sizeof(*core), GFP_KERNEL);
@@ -3351,33 +3522,9 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
 	core->max_rate = ULONG_MAX;
 	hw->core = core;
 
-	/* allocate local copy in case parent_names is __initdata */
-	core->parent_names = kcalloc(core->num_parents, sizeof(char *),
-					GFP_KERNEL);
-
-	if (!core->parent_names) {
-		ret = -ENOMEM;
-		goto fail_parent_names;
-	}
-
-
-	/* copy each string name in case parent_names is __initdata */
-	for (i = 0; i < core->num_parents; i++) {
-		core->parent_names[i] = kstrdup_const(hw->init->parent_names[i],
-						GFP_KERNEL);
-		if (!core->parent_names[i]) {
-			ret = -ENOMEM;
-			goto fail_parent_names_copy;
-		}
-	}
-
-	/* 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;
+	ret = clk_core_populate_parent_map(core);
+	if (ret)
 		goto fail_parents;
-	};
 
 	INIT_HLIST_HEAD(&core->clks);
 
@@ -3388,7 +3535,7 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
 	hw->clk = alloc_clk(core, NULL, NULL);
 	if (IS_ERR(hw->clk)) {
 		ret = PTR_ERR(hw->clk);
-		goto fail_parents;
+		goto fail_create_clk;
 	}
 
 	clk_core_link_consumer(hw->core, hw->clk);
@@ -3404,13 +3551,9 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
 	free_clk(hw->clk);
 	hw->clk = NULL;
 
+fail_create_clk:
+	clk_core_free_parent_map(core);
 fail_parents:
-	kfree(core->parents);
-fail_parent_names_copy:
-	while (--i >= 0)
-		kfree_const(core->parent_names[i]);
-	kfree(core->parent_names);
-fail_parent_names:
 fail_ops:
 	kfree_const(core->name);
 fail_name:
@@ -3473,15 +3616,10 @@ EXPORT_SYMBOL_GPL(of_clk_hw_register);
 static void __clk_release(struct kref *ref)
 {
 	struct clk_core *core = container_of(ref, struct clk_core, ref);
-	int i = core->num_parents;
 
 	lockdep_assert_held(&prepare_lock);
 
-	kfree(core->parents);
-	while (--i >= 0)
-		kfree_const(core->parent_names[i]);
-
-	kfree(core->parent_names);
+	clk_core_free_parent_map(core);
 	kfree_const(core->name);
 	kfree(core);
 }