diff --git a/ChangeLog b/ChangeLog
index c897ce17118..0297310651d 100755
--- a/ChangeLog
+++ b/ChangeLog
@@ -11049,4 +11049,7 @@
 	* Many files: Standardize naming of the user LED interface functions.
 	  The new user LED interface functions are now prototyped in only in
 	  include/nuttx/board.h and have name like board_userled_* (2015-11-01).
+	* Rename ioexpander/ directories to discrete/.  This expands the
+	  namespace so that other discrete I/O drivers can reside there as
+	  well (2015-11-01).
 
diff --git a/drivers/Kconfig b/drivers/Kconfig
index 263001d9cca..16fa26de7d0 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -292,16 +292,16 @@ if INPUT
 source drivers/input/Kconfig
 endif # INPUT
 
-menuconfig IOEXPANDER
-	bool "IO Expanders Support"
+menuconfig DISCRETE_IO
+	bool "Discrete I/O"
 	default n
 	---help---
-		This directory holds implementations of IO expander drivers.
-		See include/nuttx/ioexpander/ioexpander.h for registration information.
+		This directory holds implementations of IO expander and other
+		discrete I/O drivers.
 
-if IOEXPANDER
-source drivers/ioexpander/Kconfig
-endif # IOEXPANDER
+if DISCRETE_IO
+source drivers/discrete/Kconfig
+endif # DISCRETE_IO
 
 menuconfig LCD
 	bool "LCD Driver Support"
diff --git a/drivers/Makefile b/drivers/Makefile
index 086cecb2ad1..80630ed5af9 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -53,7 +53,7 @@ include analog$(DELIM)Make.defs
 include audio$(DELIM)Make.defs
 include bch$(DELIM)Make.defs
 include input$(DELIM)Make.defs
-include ioexpander$(DELIM)Make.defs
+include discrete$(DELIM)Make.defs
 include lcd$(DELIM)Make.defs
 include mmcsd$(DELIM)Make.defs
 include mtd$(DELIM)Make.defs
diff --git a/drivers/ioexpander/Kconfig b/drivers/discrete/Kconfig
similarity index 76%
rename from drivers/ioexpander/Kconfig
rename to drivers/discrete/Kconfig
index 10560410637..afeaacb8347 100644
--- a/drivers/ioexpander/Kconfig
+++ b/drivers/discrete/Kconfig
@@ -3,6 +3,15 @@
 # see the file kconfig-language.txt in the NuttX tools repository.
 #
 
+menuconfig IOEXPANDER
+	bool "IO Expander Support"
+	default n
+	---help---
+		This directory holds implementations of IO expander drivers.
+		See include/nuttx/discrete/ioexpander.h for registration information.
+
+if IOEXPANDER
+
 config IOEXPANDER_MULTIPIN
 	bool "Support multi-pin access routines"
 	default n
@@ -32,3 +41,4 @@ config PCA9555_INT_DISABLE
 		Disable driver interrupt functionality
 
 endif # IOEXPANDER_PCA9555
+endif # IOEXPANDER
diff --git a/drivers/ioexpander/Make.defs b/drivers/discrete/Make.defs
similarity index 94%
rename from drivers/ioexpander/Make.defs
rename to drivers/discrete/Make.defs
index 7e34efa8b0c..94ae462c7cc 100644
--- a/drivers/ioexpander/Make.defs
+++ b/drivers/discrete/Make.defs
@@ -1,5 +1,5 @@
 ############################################################################
-# drivers/ioexpander/Make.defs
+# drivers/discrete/Make.defs
 #
 #   Copyright (C) 2015 Gregory Nutt. All rights reserved.
 #   Author: Sebastien Lorquet <sebastien@lorquet.fr>
@@ -45,8 +45,8 @@ endif
 
 # Include io expander device driver build support
 
-DEPPATH += --dep-path ioexpander
-VPATH += :ioexpander
-CFLAGS += ${shell $(INCDIR) $(INCDIROPT) "$(CC)" $(TOPDIR)$(DELIM)drivers$(DELIM)ioexpander}
+DEPPATH += --dep-path discrete
+VPATH += :discrete
+CFLAGS += ${shell $(INCDIR) $(INCDIROPT) "$(CC)" $(TOPDIR)$(DELIM)drivers$(DELIM)discrete}
 
 endif
diff --git a/drivers/ioexpander/pca9555.c b/drivers/discrete/pca9555.c
similarity index 96%
rename from drivers/ioexpander/pca9555.c
rename to drivers/discrete/pca9555.c
index 3bf2cf1923b..ae5c117d8a1 100644
--- a/drivers/ioexpander/pca9555.c
+++ b/drivers/discrete/pca9555.c
@@ -1,5 +1,5 @@
 /****************************************************************************
- * drivers/ioexpander/pca9555.c
+ * drivers/discrete/pca9555.c
  *
  *   Copyright (C) 2015 Gregory Nutt. All rights reserved.
  *   Author: Sebastien Lorquet <sebastien@lorquet.fr>
@@ -48,7 +48,8 @@
 #include <debug.h>
 
 #include <nuttx/i2c.h>
-#include <nuttx/ioexpander/ioexpander.h>
+#include <nuttx/kmalloc.h>
+#include <nuttx/discrete/ioexpander.h>
 
 #include "pca9555.h"
 
@@ -208,7 +209,7 @@ static int pca9555_getbit(FAR struct i2c_dev_s *i2c, uint8_t addr,
  * Name: pca9555_direction
  *
  * Description:
- *  See include/nuttx/ioexpander/ioexpander.h
+ *  See include/nuttx/discrete/ioexpander.h
  *
  ****************************************************************************/
 
@@ -224,12 +225,12 @@ static int pca9555_direction(FAR struct ioexpander_dev_s *dev, uint8_t pin,
  * Name: pca9555_option
  *
  * Description:
- *  See include/nuttx/ioexpander/ioexpander.h
+ *  See include/nuttx/discrete/ioexpander.h
  *
  ****************************************************************************/
 
 static int pca9555_option(FAR struct ioexpander_dev_s *dev, uint8_t pin,
-                          int opt, void *val)
+                          int opt, FAR void *val)
 {
   FAR struct pca9555_dev_s *pca = (FAR struct pca9555_dev_s *)dev;
   int ival = (int)val;
@@ -246,7 +247,7 @@ static int pca9555_option(FAR struct ioexpander_dev_s *dev, uint8_t pin,
  * Name: pca9555_write
  *
  * Description:
- *  See include/nuttx/ioexpander/ioexpander.h
+ *  See include/nuttx/discrete/ioexpander.h
  *
  ****************************************************************************/
 
@@ -261,7 +262,7 @@ static int pca9555_write(FAR struct ioexpander_dev_s *dev, uint8_t pin,
  * Name: pca9555_readpin
  *
  * Description:
- *  See include/nuttx/ioexpander/ioexpander.h
+ *  See include/nuttx/discrete/ioexpander.h
  *
  ****************************************************************************/
 
@@ -276,7 +277,7 @@ static int pca9555_readpin(FAR struct ioexpander_dev_s *dev, uint8_t pin,
  * Name: pca9555_readbuf
  *
  * Description:
- *  See include/nuttx/ioexpander/ioexpander.h
+ *  See include/nuttx/discrete/ioexpander.h
  *
  ****************************************************************************/
 
@@ -340,7 +341,7 @@ static int pca9555_getmultibits(FAR struct i2c_dev_s *i2c, uint8_t addr,
  * Name: pca9555_multiwrite
  *
  * Description:
- *  See include/nuttx/ioexpander/ioexpander.h
+ *  See include/nuttx/discrete/ioexpander.h
  *
  ****************************************************************************/
 
@@ -402,7 +403,7 @@ static int pca9555_multiwrite(FAR struct ioexpander_dev_s *dev,
  * Name: pca9555_multireadpin
  *
  * Description:
- *  See include/nuttx/ioexpander/ioexpander.h
+ *  See include/nuttx/discrete/ioexpander.h
  *
  ****************************************************************************/
 
@@ -419,7 +420,7 @@ static int pca9555_multireadpin(FAR struct ioexpander_dev_s *dev,
  * Name: pca9555_multireadbuf
  *
  * Description:
- *  See include/nuttx/ioexpander/ioexpander.h
+ *  See include/nuttx/discrete/ioexpander.h
  *
  ****************************************************************************/
 
@@ -440,7 +441,7 @@ static int pca9555_multireadbuf(FAR struct ioexpander_dev_s *dev,
  * Name: pca9555_gpioworker
  *
  * Description:
- *  See include/nuttx/ioexpander/ioexpander.h
+ *  See include/nuttx/discrete/ioexpander.h
  *
  ****************************************************************************/
 
diff --git a/drivers/ioexpander/pca9555.h b/drivers/discrete/pca9555.h
similarity index 95%
rename from drivers/ioexpander/pca9555.h
rename to drivers/discrete/pca9555.h
index ef0495a9f4c..2586937c83c 100644
--- a/drivers/ioexpander/pca9555.h
+++ b/drivers/discrete/pca9555.h
@@ -1,5 +1,5 @@
 /********************************************************************************************
- * drivers/ioexpander/pca9555.h
+ * drivers/discrete/pca9555.h
  *
  *   Copyright (C) 2015 Gregory Nutt. All rights reserved.
  *   Author: Sebastien Lorquet <sebastien@lorquet.fr>
@@ -37,8 +37,8 @@
  *
  ********************************************************************************************/
 
-#ifndef __DRIVERS_IOEXPANDER_PCA9555_H
-#define __DRIVERS_IOEXPANDER_PCA9555_H
+#ifndef __DRIVERS_DISCRETE_PCA9555_H
+#define __DRIVERS_DISCRETE_PCA9555_H
 
 /********************************************************************************************
  * Included Files
@@ -49,8 +49,8 @@
 #include <nuttx/wdog.h>
 #include <nuttx/clock.h>
 #include <nuttx/wqueue.h>
-#include <nuttx/ioexpander/ioexpander.h>
-#include <nuttx/ioexpander/pca9555.h>
+#include <nuttx/discrete/ioexpander.h>
+#include <nuttx/discrete/pca9555.h>
 
 #include <nuttx/i2c.h>
 #include <nuttx/irq.h>
@@ -139,4 +139,4 @@ struct pca9555_dev_s
 };
 
 #endif /* CONFIG_IOEXPANDER && CONFIG_IOEXPANDER_PCA9555 */
-#endif /* __DRIVERS_IOEXPANDER_PCA9555_H */
+#endif /* __DRIVERS_DISCRETE_PCA9555_H */
diff --git a/include/nuttx/ioexpander/ioexpander.h b/include/nuttx/discrete/ioexpander.h
similarity index 98%
rename from include/nuttx/ioexpander/ioexpander.h
rename to include/nuttx/discrete/ioexpander.h
index 96d4197a724..609961d8959 100644
--- a/include/nuttx/ioexpander/ioexpander.h
+++ b/include/nuttx/discrete/ioexpander.h
@@ -1,5 +1,5 @@
 /****************************************************************************
- * include/nuttx/ioexpander/ioexpander.h
+ * include/nuttx/discrete/ioexpander.h
  *
  *   Copyright (C) 2015 Gregory Nutt. All rights reserved.
  *   Author: Sebastien Lorquet <sebastien@lorquet.fr>
@@ -33,8 +33,8 @@
  *
  ****************************************************************************/
 
-#ifndef __INCLUDE_NUTTX_IOEXPANDER_IOEXPANDER_H
-#define __INCLUDE_NUTTX_IOEXPANDER_IOEXPANDER_H
+#ifndef __INCLUDE_NUTTX_DISCRETE_IOEXPANDER_H
+#define __INCLUDE_NUTTX_DISCRETE_IOEXPANDER_H
 
 /****************************************************************************
  * Included Files
@@ -252,5 +252,5 @@ struct ioexpander_dev_s
 };
 
 #endif //CONFIG_IOEXPANDER
-#endif //__INCLUDE_NUTTX_IOEXPANDER_IOEXPANDER_H
+#endif //__INCLUDE_NUTTX_DISCRETE_IOEXPANDER_H
 
diff --git a/include/nuttx/ioexpander/pca9555.h b/include/nuttx/discrete/pca9555.h
similarity index 96%
rename from include/nuttx/ioexpander/pca9555.h
rename to include/nuttx/discrete/pca9555.h
index b8c857a3e7e..fea1bdb3d44 100644
--- a/include/nuttx/ioexpander/pca9555.h
+++ b/include/nuttx/discrete/pca9555.h
@@ -1,5 +1,5 @@
 /********************************************************************************************
- * include/nuttx/ioexpander/pca9555.h
+ * include/nuttx/discrete/pca9555.h
  *
  *   Copyright (C) 2015 Gregory Nutt. All rights reserved.
  *   Author: Sebastien Lorquet <sebastien@lorquet.fr>
@@ -37,8 +37,8 @@
  *
  ********************************************************************************************/
 
-#ifndef __INCLUDE_NUTTX_IOEXPANDER_PCA9555_H
-#define __INCLUDE_NUTTX_IOEXPANDER_PCA9555_H
+#ifndef __INCLUDE_NUTTX_DISCRETE_PCA9555_H
+#define __INCLUDE_NUTTX_DISCRETE_PCA9555_H
 
 #include <nuttx/i2c.h>
 
@@ -120,4 +120,4 @@ FAR struct ioexpander_dev_s* pca9555_initialize(FAR struct i2c_dev_s *dev,
 }
 #endif
 
-#endif /* __INCLUDE_NUTTX_IOEXPANDER_PCA9555_H */
+#endif /* __INCLUDE_NUTTX_DISCRETE_PCA9555_H */