diff --git a/src/flash/arm_nandio.h b/src/flash/arm_nandio.h
index 27b3ad351..d3504f434 100644
--- a/src/flash/arm_nandio.h
+++ b/src/flash/arm_nandio.h
@@ -1,25 +1,55 @@
+/*
+ * Copyright (C) 2009 by David Brownell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the
+ * Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
 #ifndef __ARM_NANDIO_H
 #define __ARM_NANDIO_H
 
 #include <flash/nand.h>
 #include <helper/binarybuffer.h>
 
+/**
+ * Available operational states the arm_nand_data struct can be in.
+ */
+enum arm_nand_op {
+	ARM_NAND_NONE, /**< No operation performed. */
+	ARM_NAND_READ, /**< Read operation performed. */
+	ARM_NAND_WRITE, /**< Write operation performed. */
+};
+
 /**
  * The arm_nand_data struct is used for defining NAND I/O operations on an ARM
  * core.
  */
 struct arm_nand_data {
-	/** target is proxy for some ARM core */
-	struct target		*target;
+	/** Target is proxy for some ARM core. */
+	struct target *target;
 
-	/** copy_area holds write-to-NAND loop and data to write */
+	/** The copy area holds code loop and data for I/O operations. */
 	struct working_area	*copy_area;
 
-	/** chunk_size == page or ECC unit */
-	unsigned		chunk_size;
+	/** The chunk size is the page size or ECC chunk. */
+	unsigned chunk_size;
 
-	/** data == where to write the data */
-	uint32_t		data;
+	/** Where data is read from or written to. */
+	uint32_t data;
+
+	/** Last operation executed using this struct. */
+	enum arm_nand_op op;
 
 	/* currently implicit:  data width == 8 bits (not 16) */
 };
diff --git a/src/flash/nand/davinci.c b/src/flash/nand/davinci.c
index 40be36d46..66770737c 100644
--- a/src/flash/nand/davinci.c
+++ b/src/flash/nand/davinci.c
@@ -710,6 +710,7 @@ NAND_DEVICE_COMMAND_HANDLER(davinci_nand_device_command)
 
 	info->io.target = target;
 	info->io.data = info->data;
+	info->io.op = ARM_NAND_NONE;
 
 	/* NOTE:  for now we don't do any error correction on read.
 	 * Nothing else in OpenOCD currently corrects read errors,
diff --git a/src/flash/nand/orion.c b/src/flash/nand/orion.c
index 436151fba..b124deee6 100644
--- a/src/flash/nand/orion.c
+++ b/src/flash/nand/orion.c
@@ -155,6 +155,7 @@ NAND_DEVICE_COMMAND_HANDLER(orion_nand_device_command)
 
 	hw->io.target = hw->target;
 	hw->io.data = hw->data;
+	hw->io.op = ARM_NAND_NONE;
 
 	return ERROR_OK;
 }