Revert "of/platform: Add functional dependency link from DT bindings"

This reverts commit 690ff788.

Based on a lot of email and in-person discussions, this patch series is
being reworked to address a number of issues that were pointed out that
needed to be taken care of before it should be merged.  It will be
resubmitted with those changes hopefully soon.

Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Saravana Kannan <saravanak@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/admin-guide/kernel-parameters.txt

@@ -3170,11 +3170,6 @@
 			This can be set from sysctl after boot.
 			See Documentation/admin-guide/sysctl/vm.rst for details.
 
-	of_devlink	[KNL] Make device links from common DT bindings. Useful
-			for optimizing probe order and making sure resources
-			aren't turned off before the consumer devices have
-			probed.
-
 	ohci1394_dma=early	[HW] enable debugging via the ohci1394 driver.
 			See Documentation/debugging-via-ohci1394.txt for more
 			info.

drivers/of/platform.c

@@ -503,170 +503,6 @@ int of_platform_default_populate(struct device_node *root,
 }
 EXPORT_SYMBOL_GPL(of_platform_default_populate);
 
-bool of_link_is_valid(struct device_node *con, struct device_node *sup)
-{
-	of_node_get(sup);
-	/*
-	 * Don't allow linking a device node as a consumer of one of its
-	 * descendant nodes. By definition, a child node can't be a functional
-	 * dependency for the parent node.
-	 */
-	while (sup) {
-		if (sup == con) {
-			of_node_put(sup);
-			return false;
-		}
-		sup = of_get_next_parent(sup);
-	}
-	return true;
-}
-
-static int of_link_to_phandle(struct device *dev, struct device_node *sup_np)
-{
-	struct platform_device *sup_dev;
-	u32 dl_flags = DL_FLAG_AUTOPROBE_CONSUMER;
-	int ret = 0;
-
-	/*
-	 * Since we are trying to create device links, we need to find
-	 * the actual device node that owns this supplier phandle.
-	 * Often times it's the same node, but sometimes it can be one
-	 * of the parents. So walk up the parent till you find a
-	 * device.
-	 */
-	while (sup_np && !of_find_property(sup_np, "compatible", NULL))
-		sup_np = of_get_next_parent(sup_np);
-	if (!sup_np)
-		return 0;
-
-	if (!of_link_is_valid(dev->of_node, sup_np)) {
-		of_node_put(sup_np);
-		return 0;
-	}
-	sup_dev = of_find_device_by_node(sup_np);
-	of_node_put(sup_np);
-	if (!sup_dev)
-		return -ENODEV;
-	if (!device_link_add(dev, &sup_dev->dev, dl_flags))
-		ret = -ENODEV;
-	put_device(&sup_dev->dev);
-	return ret;
-}
-
-static struct device_node *parse_prop_cells(struct device_node *np,
-					    const char *prop, int index,
-					    const char *binding,
-					    const char *cell)
-{
-	struct of_phandle_args sup_args;
-
-	/* Don't need to check property name for every index. */
-	if (!index && strcmp(prop, binding))
-		return NULL;
-
-	if (of_parse_phandle_with_args(np, binding, cell, index, &sup_args))
-		return NULL;
-
-	return sup_args.np;
-}
-
-static struct device_node *parse_clocks(struct device_node *np,
-					const char *prop, int index)
-{
-	return parse_prop_cells(np, prop, index, "clocks", "#clock-cells");
-}
-
-static struct device_node *parse_interconnects(struct device_node *np,
-					       const char *prop, int index)
-{
-	return parse_prop_cells(np, prop, index, "interconnects",
-				"#interconnect-cells");
-}
-
-static int strcmp_suffix(const char *str, const char *suffix)
-{
-	unsigned int len, suffix_len;
-
-	len = strlen(str);
-	suffix_len = strlen(suffix);
-	if (len <= suffix_len)
-		return -1;
-	return strcmp(str + len - suffix_len, suffix);
-}
-
-static struct device_node *parse_regulators(struct device_node *np,
-					    const char *prop, int index)
-{
-	if (index || strcmp_suffix(prop, "-supply"))
-		return NULL;
-
-	return of_parse_phandle(np, prop, 0);
-}
-
-/**
- * struct supplier_bindings - Information for parsing supplier DT binding
- *
- * @parse_prop:		If the function cannot parse the property, return NULL.
- *			Otherwise, return the phandle listed in the property
- *			that corresponds to the index.
- */
-struct supplier_bindings {
-	struct device_node *(*parse_prop)(struct device_node *np,
-					  const char *name, int index);
-};
-
-static const struct supplier_bindings bindings[] = {
-	{ .parse_prop = parse_clocks, },
-	{ .parse_prop = parse_interconnects, },
-	{ .parse_prop = parse_regulators, },
-	{ },
-};
-
-static bool of_link_property(struct device *dev, struct device_node *con_np,
-			     const char *prop)
-{
-	struct device_node *phandle;
-	const struct supplier_bindings *s = bindings;
-	unsigned int i = 0;
-	bool done = true, matched = false;
-
-	while (!matched && s->parse_prop) {
-		while ((phandle = s->parse_prop(con_np, prop, i))) {
-			matched = true;
-			i++;
-			if (of_link_to_phandle(dev, phandle))
-				/*
-				 * Don't stop at the first failure. See
-				 * Documentation for bus_type.add_links for
-				 * more details.
-				 */
-				done = false;
-		}
-		s++;
-	}
-	return done ? 0 : -ENODEV;
-}
-
-static bool of_devlink;
-core_param(of_devlink, of_devlink, bool, 0);
-
-static int of_link_to_suppliers(struct device *dev)
-{
-	struct property *p;
-	bool done = true;
-
-	if (!of_devlink)
-		return 0;
-	if (unlikely(!dev->of_node))
-		return 0;
-
-	for_each_property_of_node(dev->of_node, p)
-		if (of_link_property(dev, dev->of_node, p->name))
-			done = false;
-
-	return done ? 0 : -ENODEV;
-}
-
 #ifndef CONFIG_PPC
 static const struct of_device_id reserved_mem_matches[] = {
 	{ .compatible = "qcom,rmtfs-mem" },
@@ -682,7 +518,6 @@ static int __init of_platform_default_populate_init(void)
 	if (!of_have_populated_dt())
 		return -ENODEV;
 
-	platform_bus_type.add_links = of_link_to_suppliers;
 	/*
 	 * Handle certain compatibles explicitly, since we don't want to create
 	 * platform_devices for every node in /reserved-memory with a