fdt: Add fdtdec_get_addr_size() to read reg properties

It is common to have a "reg = <address size>" property in the FDT.
Add a function to handle this, similar to the existing
fdtdec_get_addr();

Signed-off-by: Simon Glass <sjg@chromium.org>

include/fdtdec.h

@@ -38,11 +38,13 @@
  */
 #ifdef CONFIG_PHYS_64BIT
 typedef u64 fdt_addr_t;
+typedef u64 fdt_size_t;
 #define FDT_ADDR_T_NONE (-1ULL)
 #define fdt_addr_to_cpu(reg) be64_to_cpu(reg)
 #define fdt_size_to_cpu(reg) be64_to_cpu(reg)
 #else
 typedef u32 fdt_addr_t;
+typedef u32 fdt_size_t;
 #define FDT_ADDR_T_NONE (-1U)
 #define fdt_addr_to_cpu(reg) be32_to_cpu(reg)
 #define fdt_size_to_cpu(reg) be32_to_cpu(reg)
@@ -200,6 +202,19 @@ fdt_addr_t fdtdec_get_addr(const void *blob, int node,
 		const char *prop_name);
 
 /**
+ * Look up an address property in a node and return it as an address.
+ * The property must hold one address with a length. This is only tested
+ * on 32-bit machines.
+ *
+ * @param blob	FDT blob
+ * @param node	node to examine
+ * @param prop_name	name of property to find
+ * @return address, if found, or FDT_ADDR_T_NONE if not
+ */
+fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
+		const char *prop_name, fdt_size_t *sizep);
+
+/**
  * Look up a 32-bit integer property in a node and return it. The property
  * must have at least 4 bytes of data. The value of the first cell is
  * returned.

lib/fdtdec.c

@@ -68,25 +68,40 @@ const char *fdtdec_get_compatible(enum fdt_compat_id id)
 	return compat_names[id];
 }
 
-fdt_addr_t fdtdec_get_addr(const void *blob, int node,
-		const char *prop_name)
+fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
+		const char *prop_name, fdt_size_t *sizep)
 {
 	const fdt_addr_t *cell;
 	int len;
 
 	debug("%s: %s: ", __func__, prop_name);
 	cell = fdt_getprop(blob, node, prop_name, &len);
-	if (cell && (len == sizeof(fdt_addr_t) ||
-			len == sizeof(fdt_addr_t) * 2)) {
+	if (cell && ((!sizep && len == sizeof(fdt_addr_t)) ||
+		     len == sizeof(fdt_addr_t) * 2)) {
 		fdt_addr_t addr = fdt_addr_to_cpu(*cell);
-
-		debug("%p\n", (void *)addr);
+		if (sizep) {
+			const fdt_size_t *size;
+
+			size = (fdt_size_t *)((char *)cell +
+					sizeof(fdt_addr_t));
+			*sizep = fdt_size_to_cpu(*size);
+			debug("addr=%p, size=%p\n", (void *)addr,
+			      (void *)*sizep);
+		} else {
+			debug("%p\n", (void *)addr);
+		}
 		return addr;
 	}
 	debug("(not found)\n");
 	return FDT_ADDR_T_NONE;
 }
 
+fdt_addr_t fdtdec_get_addr(const void *blob, int node,
+		const char *prop_name)
+{
+	return fdtdec_get_addr_size(blob, node, prop_name, NULL);
+}
+
 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
 		s32 default_val)
 {