drivers/of: Add empty ranges quirk for PA-Semi

commit a5ed1ad0 upstream.

The "sdc" node is missing the ranges property, it needs to be treated
as having an empty one otherwise translation fails for its children.

Fixes 746c9e9f, "of/base: Fix PowerPC address parsing hack"
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/of/address.c

@@ -403,12 +403,17 @@ static struct of_bus *of_match_bus(struct device_node *np)
 	return NULL;
 }
 
-static int of_empty_ranges_quirk(void)
+static int of_empty_ranges_quirk(struct device_node *np)
 {
 	if (IS_ENABLED(CONFIG_PPC)) {
-		/* To save cycles, we cache the result */
+		/* To save cycles, we cache the result for global "Mac" setting */
 		static int quirk_state = -1;
 
+		/* PA-SEMI sdc DT bug */
+		if (of_device_is_compatible(np, "1682m-sdc"))
+			return true;
+
+		/* Make quirk cached */
 		if (quirk_state < 0)
 			quirk_state =
 				of_machine_is_compatible("Power Macintosh") ||
@@ -443,7 +448,7 @@ static int of_translate_one(struct device_node *parent, struct of_bus *bus,
 	 * This code is only enabled on powerpc. --gcl
 	 */
 	ranges = of_get_property(parent, rprop, &rlen);
-	if (ranges == NULL && !of_empty_ranges_quirk()) {
+	if (ranges == NULL && !of_empty_ranges_quirk(parent)) {
 		pr_err("OF: no ranges; cannot translate\n");
 		return 1;
 	}