Merge branch 'clk-parent-rewrite-1' into clk-next

- Rewrite how clk parents can be specified to be DT/clkdev based instead
of just string based

* clk-parent-rewrite-1:
clk: Cache core in clk_fetch_parent_index() without names
clk: fixed-factor: Initialize clk_init_data on stack
clk: fixed-factor: Let clk framework find parent
clk: Allow parents to be specified via clkspec index
clk: Look for parents with clkdev based clk_lookups
clk: Allow parents to be specified without string names
clk: Add of_clk_hw_register() API for early clk drivers
driver core: Let dev_of_node() accept a NULL dev
clk: Prepare for clk registration API that uses DT nodes
clkdev: Move clk creation outside of 'clocks_mutex'

drivers/clk/clk-fixed-factor.c

···
 };
 EXPORT_SYMBOL_GPL(clk_fixed_factor_ops);
 
-struct clk_hw *clk_hw_register_fixed_factor(struct device *dev,
-		const char *name, const char *parent_name, unsigned long flags,
-		unsigned int mult, unsigned int div)
+static struct clk_hw *
+__clk_hw_register_fixed_factor(struct device *dev, struct device_node *np,
+		const char *name, const char *parent_name, int index,
+		unsigned long flags, unsigned int mult, unsigned int div)
 {
 	struct clk_fixed_factor *fix;
-	struct clk_init_data init;
+	struct clk_init_data init = { };
+	struct clk_parent_data pdata = { .index = index };
 	struct clk_hw *hw;
 	int ret;
 
···
 	init.name = name;
 	init.ops = &clk_fixed_factor_ops;
 	init.flags = flags;
-	init.parent_names = &parent_name;
+	if (parent_name)
+		init.parent_names = &parent_name;
+	else
+		init.parent_data = &pdata;
 	init.num_parents = 1;
 
 	hw = &fix->hw;
-	ret = clk_hw_register(dev, hw);
+	if (dev)
+		ret = clk_hw_register(dev, hw);
+	else
+		ret = of_clk_hw_register(np, hw);
 	if (ret) {
 		kfree(fix);
 		hw = ERR_PTR(ret);
 	}
 
 	return hw;
+}
+
+struct clk_hw *clk_hw_register_fixed_factor(struct device *dev,
+		const char *name, const char *parent_name, unsigned long flags,
+		unsigned int mult, unsigned int div)
+{
+	return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, -1,
+					      flags, mult, div);
 }
 EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor);
 
···
 	{ /* Sentinel */ },
 };
 
-static struct clk *_of_fixed_factor_clk_setup(struct device_node *node)
+static struct clk_hw *_of_fixed_factor_clk_setup(struct device_node *node)
 {
-	struct clk *clk;
+	struct clk_hw *hw;
 	const char *clk_name = node->name;
-	const char *parent_name;
 	unsigned long flags = 0;
 	u32 div, mult;
 	int ret;
···
 	}
 
 	of_property_read_string(node, "clock-output-names", &clk_name);
-	parent_name = of_clk_get_parent_name(node, 0);
 
 	if (of_match_node(set_rate_parent_matches, node))
 		flags |= CLK_SET_RATE_PARENT;
 
-	clk = clk_register_fixed_factor(NULL, clk_name, parent_name, flags,
-					mult, div);
-	if (IS_ERR(clk)) {
+	hw = __clk_hw_register_fixed_factor(NULL, node, clk_name, NULL, 0,
+					    flags, mult, div);
+	if (IS_ERR(hw)) {
 		/*
-		 * If parent clock is not registered, registration would fail.
 		 * Clear OF_POPULATED flag so that clock registration can be
 		 * attempted again from probe function.
 		 */
 		of_node_clear_flag(node, OF_POPULATED);
-		return clk;
+		return ERR_CAST(hw);
 	}
 
-	ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);
+	ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
 	if (ret) {
-		clk_unregister(clk);
+		clk_hw_unregister_fixed_factor(hw);
 		return ERR_PTR(ret);
 	}
 
-	return clk;
+	return hw;
 }
 
 /**
···
 
 static int of_fixed_factor_clk_remove(struct platform_device *pdev)
 {
-	struct clk *clk = platform_get_drvdata(pdev);
+	struct clk_hw *clk = platform_get_drvdata(pdev);
 
 	of_clk_del_provider(pdev->dev.of_node);
-	clk_unregister_fixed_factor(clk);
+	clk_hw_unregister_fixed_factor(clk);
 
 	return 0;
 }
 
 static int of_fixed_factor_clk_probe(struct platform_device *pdev)
 {
-	struct clk *clk;
+	struct clk_hw *clk;
 
 	/*
 	 * This function is not executed when of_fixed_factor_clk_setup

drivers/clk/clk.c

···
 
 /***    private data structures    ***/
 
+struct clk_parent_map {
+	const struct clk_hw	*hw;
+	struct clk_core		*core;
+	const char		*fw_name;
+	const char		*name;
+	int			index;
+};
+
 struct clk_core {
 	const char		*name;
 	const struct clk_ops	*ops;
 	struct clk_hw		*hw;
 	struct module		*owner;
 	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;
···
 	return NULL;
 }
 
+/**
+ * clk_core_get - Find the clk_core parent of a clk
+ * @core: clk to find parent of
+ * @p_index: parent index to search for
+ *
+ * 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 or as the 'con_id' matching the device's
+ * dev_name() in a clk_lookup. 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, u8 p_index)
+{
+	const char *name = core->parents[p_index].fw_name;
+	int index = core->parents[p_index].index;
+	struct clk_hw *hw = ERR_PTR(-ENOENT);
+	struct device *dev = core->dev;
+	const char *dev_id = dev ? dev_name(dev) : NULL;
+	struct device_node *np = core->of_node;
+
+	if (np && index >= 0)
+		hw = of_clk_get_hw(np, index, name);
+
+	/*
+	 * If the DT search above couldn't find the provider or the provider
+	 * didn't know about this clk, fallback to looking up via clkdev based
+	 * clk_lookups
+	 */
+	if (PTR_ERR(hw) == -ENOENT && name)
+		hw = clk_find_hw(dev_id, name);
+
+	if (IS_ERR(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 {
+		parent = clk_core_get(core, index);
+		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 *
···
 		return -EINVAL;
 
 	for (i = 0; i < core->num_parents; i++) {
-		if (core->parents[i] == parent)
+		/* Found it first try! */
+		if (core->parents[i].core == parent)
 			return i;
 
-		if (core->parents[i])
+		/* Something else is here, so keep looking */
+		if (core->parents[i].core)
 			continue;
 
-		/* Fallback to comparing globally unique names */
-		if (!strcmp(parent->name, core->parent_names[i])) {
-			core->parents[i] = parent;
-			return i;
+		/* Maybe core hasn't been cached but the hw is all we know? */
+		if (core->parents[i].hw) {
+			if (core->parents[i].hw == parent->hw)
+				break;
+
+			/* Didn't match, but we're expecting a clk_hw */
+			continue;
 		}
+
+		/* Maybe it hasn't been cached (clk_set_parent() path) */
+		if (parent == clk_core_get(core, i))
+			break;
+
+		/* Fallback to comparing globally unique names */
+		if (!strcmp(parent->name, core->parents[i].name))
+			break;
 	}
 
-	return -EINVAL;
+	if (i == core->num_parents)
+		return -EINVAL;
+
+	core->parents[i].core = parent;
+	return i;
 }
 
 /*
···
 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)
···
 	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);
 
···
 	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;
 }
···
  */
 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;
···
 		ret = -EINVAL;
 		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);
 
···
 	return 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 *deprecated* interface for populating the clock tree with
- * new clock nodes. Use clk_hw_register() instead.
- *
- * Returns: a pointer to the newly allocated struct clk which
- * cannot be dereferenced by driver code but may be used in conjunction 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)
+static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
 {
-	int i, ret;
+	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++) {
+		parent->index = -1;
+		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;
+			parent->index = parent_data[i].index;
+			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 ret;
 	struct clk_core *core;
 
 	core = kzalloc(sizeof(*core), GFP_KERNEL);
···
 	if (dev && pm_runtime_enabled(dev))
 		core->rpm_enabled = true;
 	core->dev = dev;
+	core->of_node = np;
 	if (dev && dev->driver)
 		core->owner = dev->driver->owner;
 	core->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);
 
···
 	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);
···
 	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:
 	kfree(core);
 fail_out:
 	return ERR_PTR(ret);
+}
+
+/**
+ * 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 *deprecated* interface for populating the clock tree with
+ * new clock nodes. Use clk_hw_register() instead.
+ *
+ * Returns: a pointer to the newly allocated struct clk which
+ * cannot be dereferenced by driver code but may be used in conjunction 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)
+{
+	return __clk_register(dev, dev_of_node(dev), hw);
 }
 EXPORT_SYMBOL_GPL(clk_register);
 
···
  */
 int clk_hw_register(struct device *dev, struct clk_hw *hw)
 {
-	return PTR_ERR_OR_ZERO(clk_register(dev, hw));
+	return PTR_ERR_OR_ZERO(__clk_register(dev, dev_of_node(dev), hw));
 }
 EXPORT_SYMBOL_GPL(clk_hw_register);
+
+/*
+ * of_clk_hw_register - register a clk_hw and return an error code
+ * @node: device_node of device that is registering this clock
+ * @hw: link to hardware-specific clock data
+ *
+ * of_clk_hw_register() is the primary interface for populating the clock tree
+ * with new clock nodes when a struct device is not available, but a struct
+ * device_node is. It returns an integer equal to zero indicating success or
+ * less than zero indicating failure. Drivers must test for an error code after
+ * calling of_clk_hw_register().
+ */
+int of_clk_hw_register(struct device_node *node, struct clk_hw *hw)
+{
+	return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw));
+}
+EXPORT_SYMBOL_GPL(of_clk_hw_register);
 
 /* Free memory allocated for a clock. */
 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);
 }

drivers/clk/clk.h

···
 }
 #endif
 
+struct clk_hw *clk_find_hw(const char *dev_id, const char *con_id);
+
 #ifdef CONFIG_COMMON_CLK
 struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
 			      const char *dev_id, const char *con_id);

drivers/clk/clkdev.c

···
 	return cl;
 }
 
+struct clk_hw *clk_find_hw(const char *dev_id, const char *con_id)
+{
+	struct clk_lookup *cl;
+	struct clk_hw *hw = ERR_PTR(-ENOENT);
+
+	mutex_lock(&clocks_mutex);
+	cl = clk_find(dev_id, con_id);
+	if (cl)
+		hw = cl->clk_hw;
+	mutex_unlock(&clocks_mutex);
+
+	return hw;
+}
+
 static struct clk *__clk_get_sys(struct device *dev, const char *dev_id,
 				 const char *con_id)
 {
-	struct clk_lookup *cl;
-	struct clk *clk = NULL;
+	struct clk_hw *hw = clk_find_hw(dev_id, con_id);
 
-	mutex_lock(&clocks_mutex);
-
-	cl = clk_find(dev_id, con_id);
-	if (!cl)
-		goto out;
-
-	clk = clk_hw_create_clk(dev, cl->clk_hw, dev_id, con_id);
-	if (IS_ERR(clk))
-		cl = NULL;
-out:
-	mutex_unlock(&clocks_mutex);
-
-	return cl ? clk : ERR_PTR(-ENOENT);
+	return clk_hw_create_clk(dev, hw, dev_id, con_id);
 }
 
 struct clk *clk_get_sys(const char *dev_id, const char *con_id)

include/linux/clk-provider.h

···
 };
 
 /**
+ * struct clk_parent_data - clk parent information
+ * @hw: parent clk_hw pointer (used for clk providers with internal clks)
+ * @fw_name: parent name local to provider registering clk
+ * @name: globally unique parent name (used as a fallback)
+ * @index: parent index local to provider registering clk (if @fw_name absent)
+ */
+struct clk_parent_data {
+	const struct clk_hw	*hw;
+	const char		*fw_name;
+	const char		*name;
+	int			index;
+};
+
+/**
  * struct clk_init_data - holds init data that's common to all clocks and is
  * shared between the clock provider and the common clock framework.
  *
  * @name: clock name
  * @ops: operations this clock supports
  * @parent_names: array of string names for all possible parents
+ * @parent_data: array of parent data for all possible parents (when some
+ *               parents are external to the clk controller)
+ * @parent_hws: array of pointers to all possible parents (when all parents
+ *              are internal to the clk controller)
  * @num_parents: number of possible parents
  * @flags: framework-level hints and quirks
  */
 struct clk_init_data {
 	const char		*name;
 	const struct clk_ops	*ops;
+	/* Only one of the following three should be assigned */
 	const char		* const *parent_names;
+	const struct clk_parent_data	*parent_data;
+	const struct clk_hw		**parent_hws;
 	u8			num_parents;
 	unsigned long		flags;
 };
···
 
 int __must_check clk_hw_register(struct device *dev, struct clk_hw *hw);
 int __must_check devm_clk_hw_register(struct device *dev, struct clk_hw *hw);
+int __must_check of_clk_hw_register(struct device_node *node, struct clk_hw *hw);
 
 void clk_unregister(struct clk *clk);
 void devm_clk_unregister(struct device *dev, struct clk *clk);

include/linux/device.h

···
 
 static inline struct device_node *dev_of_node(struct device *dev)
 {
-	if (!IS_ENABLED(CONFIG_OF))
+	if (!IS_ENABLED(CONFIG_OF) || !dev)
 		return NULL;
 	return dev->of_node;
 }