Merge tag 'devicetree-for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

Pull Devicetree updates from Rob Herring:

 - a bunch of DT binding conversions to DT schema format

 - clean-ups of the Arm idle-states binding

 - support a default number of cells in of_for_each_phandle() when the
   cells name is missing

 - expose dtbs_check and dt_binding_check in the make help

 - convert writting-schema.md to ReST

 - HiSilicon reset controller binding updates

 - add documentation for MT8516 RNG

* tag 'devicetree-for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (46 commits)
  of: restore old handling of cells_name=NULL in of_*_phandle_with_args()
  bus: qcom: fix spelling mistake "ambigous" -> "ambiguous"
  of: Let of_for_each_phandle fallback to non-negative cell_count
  iommu: pass cell_count = -1 to of_for_each_phandle with cells_name
  dt-bindings: arm: Convert Realtek board/soc bindings to json-schema
  dt-bindings: arm: Convert Actions Semi bindings to jsonschema
  dt-bindings: Correct spelling in example schema
  dt-bindings: cpu: Add a support cpu type for cortex-a55
  dt-bindings: gpu: mali-midgard: Add samsung exynos5250 compatible
  dt-bindings: arm: idle-states: Move exit-latency-us explanation
  dt-bindings: arm: idle-states: Add punctuation to improve readability
  dt-bindings: arm: idle-states: Correct "constraint guarantees"
  dt-bindings: arm: idle-states: Correct references to wake-up delay
  dt-bindings: arm: idle-states: Use "e.g." and "i.e." consistently
  pinctrl-mcp23s08: Fix property-name in dt-example
  dt-bindings: Clarify interrupts-extended usage
  dt-bindings: Convert Arm Mali Utgard GPU to DT schema
  dt-bindings: Convert Arm Mali Bifrost GPU to DT schema
  dt-bindings: Convert Arm Mali Midgard GPU to DT schema
  dt-bindings: irq: Convert Allwinner NMI Controller to a schema
  ...

drivers/of/base.c

@@ -1286,6 +1286,13 @@ int of_phandle_iterator_init(struct of_phandle_iterator *it,
 
 	memset(it, 0, sizeof(*it));
 
+	/*
+	 * one of cell_count or cells_name must be provided to determine the
+	 * argument length.
+	 */
+	if (cell_count < 0 && !cells_name)
+		return -EINVAL;
+
 	list = of_get_property(np, list_name, &size);
 	if (!list)
 		return -ENOENT;
@@ -1335,11 +1342,20 @@ int of_phandle_iterator_next(struct of_phandle_iterator *it)
 
 			if (of_property_read_u32(it->node, it->cells_name,
 						 &count)) {
-				pr_err("%pOF: could not get %s for %pOF\n",
-				       it->parent,
-				       it->cells_name,
-				       it->node);
-				goto err;
+				/*
+				 * If both cell_count and cells_name is given,
+				 * fall back to cell_count in absence
+				 * of the cells_name property
+				 */
+				if (it->cell_count >= 0) {
+					count = it->cell_count;
+				} else {
+					pr_err("%pOF: could not get %s for %pOF\n",
+					       it->parent,
+					       it->cells_name,
+					       it->node);
+					goto err;
+				}
 			}
 		} else {
 			count = it->cell_count;
@@ -1503,10 +1519,17 @@ int of_parse_phandle_with_args(const struct device_node *np, const char *list_na
 				const char *cells_name, int index,
 				struct of_phandle_args *out_args)
 {
+	int cell_count = -1;
+
 	if (index < 0)
 		return -EINVAL;
-	return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
-					    index, out_args);
+
+	/* If cells_name is NULL we assume a cell count of 0 */
+	if (!cells_name)
+		cell_count = 0;
+
+	return __of_parse_phandle_with_args(np, list_name, cells_name,
+					    cell_count, index, out_args);
 }
 EXPORT_SYMBOL(of_parse_phandle_with_args);
 
@@ -1588,7 +1611,7 @@ int of_parse_phandle_with_args_map(const struct device_node *np,
 	if (!pass_name)
 		goto free;
 
-	ret = __of_parse_phandle_with_args(np, list_name, cells_name, 0, index,
+	ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
 					   out_args);
 	if (ret)
 		goto free;
@@ -1756,7 +1779,24 @@ int of_count_phandle_with_args(const struct device_node *np, const char *list_na
 	struct of_phandle_iterator it;
 	int rc, cur_index = 0;
 
-	rc = of_phandle_iterator_init(&it, np, list_name, cells_name, 0);
+	/*
+	 * If cells_name is NULL we assume a cell count of 0. This makes
+	 * counting the phandles trivial as each 32bit word in the list is a
+	 * phandle and no arguments are to consider. So we don't iterate through
+	 * the list but just use the length to determine the phandle count.
+	 */
+	if (!cells_name) {
+		const __be32 *list;
+		int size;
+
+		list = of_get_property(np, list_name, &size);
+		if (!list)
+			return -ENOENT;
+
+		return size / sizeof(*list);
+	}
+
+	rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
 	if (rc)
 		return rc;
 

drivers/of/unittest.c

@@ -1044,8 +1044,10 @@ static void __init of_unittest_platform_populate(void)
 	test_bus = platform_device_register_full(&test_bus_info);
 	rc = PTR_ERR_OR_ZERO(test_bus);
 	unittest(!rc, "testbus registration failed; rc=%i\n", rc);
-	if (rc)
+	if (rc) {
+		of_node_put(np);
 		return;
+	}
 	test_bus->dev.of_node = np;
 
 	/*