dm: core: Add dev_get_addr_size_index() to retrieve addr and size

The currently available functions accessing the 'reg' property of a
device only retrieve the address. Sometimes its also necessary to
retrieve the size described by the 'reg' property. This patch adds
the new function dev_get_addr_size_index() which retrieves both,
the address and the size described by the 'reg' property.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/core/device.c b/drivers/core/device.c
index dcf5d9d..ed553d7 100644
--- a/drivers/core/device.c
+++ b/drivers/core/device.c
@@ -693,6 +693,28 @@
 #endif
 }
 
+fdt_addr_t dev_get_addr_size_index(struct udevice *dev, int index,
+				   fdt_size_t *size)
+{
+#if CONFIG_IS_ENABLED(OF_CONTROL)
+	/*
+	 * Only get the size in this first call. We'll get the addr in the
+	 * next call to the exisiting dev_get_xxx function which handles
+	 * all config options.
+	 */
+	fdtdec_get_addr_size_auto_noparent(gd->fdt_blob, dev->of_offset,
+					   "reg", index, size, false);
+
+	/*
+	 * Get the base address via the existing function which handles
+	 * all Kconfig cases
+	 */
+	return dev_get_addr_index(dev, index);
+#else
+	return FDT_ADDR_T_NONE;
+#endif
+}
+
 fdt_addr_t dev_get_addr_name(struct udevice *dev, const char *name)
 {
 #if CONFIG_IS_ENABLED(OF_CONTROL)
diff --git a/include/dm/device.h b/include/dm/device.h
index babf8ac..9948bd4 100644
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -497,6 +497,22 @@
 fdt_addr_t dev_get_addr_index(struct udevice *dev, int index);
 
 /**
+ * dev_get_addr_size_index() - Get the indexed reg property of a device
+ *
+ * Returns the address and size specified in the 'reg' property of a device.
+ *
+ * @dev: Pointer to a device
+ * @index: the 'reg' property can hold a list of <addr, size> pairs
+ *	   and @index is used to select which one is required
+ * @size: Pointer to size varible - this function returns the size
+ *        specified in the 'reg' property here
+ *
+ * @return addr
+ */
+fdt_addr_t dev_get_addr_size_index(struct udevice *dev, int index,
+				   fdt_size_t *size);
+
+/**
  * dev_get_addr_name() - Get the reg property of a device, indexed by name
  *
  * @dev: Pointer to a device