diff --git a/include/nuttx/analog/ads1242.h b/include/nuttx/analog/ads1242.h
index d8a630bd207..aeeb48da6cf 100644
--- a/include/nuttx/analog/ads1242.h
+++ b/include/nuttx/analog/ads1242.h
@@ -1,5 +1,5 @@
 /****************************************************************************
- * include/nuttx/sensors/ads1242.h
+ * include/nuttx/analog/ads1242.h
  *
  *   Copyright (C) 2016, DS-Automotion GmbH. All rights reserved.
  *   Author: Alexander Entinger <a.entinger@ds-automotion.com>
@@ -41,7 +41,7 @@
  ****************************************************************************/
 
 #include <nuttx/config.h>
-#include <nuttx/fs/ioctl.h>
+#include <nuttx/analog/ioctl.h>
 #include <nuttx/spi/spi.h>
 
 #if defined(CONFIG_SPI) && defined(CONFIG_ADC_ADS1242)
@@ -59,12 +59,12 @@
  * Cmd: ANIOC_ADS2142_DO_SYSTEM_OFFSET_CALIB  Arg: None
  */
 
-#define ANIOC_ADS2142_READ                    _ANIOC(ANIOC_USER + 0)
-#define ANIOC_ADS2142_SET_GAIN                _ANIOC(ANIOC_USER + 1)
-#define ANIOC_ADS2142_SET_POSITIVE_INPUT      _ANIOC(ANIOC_USER + 2)
-#define ANIOC_ADS2142_SET_NEGATIVE_INPUT      _ANIOC(ANIOC_USER + 3)
-#define ANIOC_ADS2142_IS_DATA_READY           _ANIOC(ANIOC_USER + 4)
-#define ANIOC_ADS2142_DO_SYSTEM_OFFSET_CALIB  _ANIOC(ANIOC_USER + 5)
+#define ANIOC_ADS2142_READ                    _ANIOC(AN_ADS2142_FIRST + 0)
+#define ANIOC_ADS2142_SET_GAIN                _ANIOC(AN_ADS2142_FIRST + 1)
+#define ANIOC_ADS2142_SET_POSITIVE_INPUT      _ANIOC(AN_ADS2142_FIRST + 2)
+#define ANIOC_ADS2142_SET_NEGATIVE_INPUT      _ANIOC(AN_ADS2142_FIRST + 3)
+#define ANIOC_ADS2142_IS_DATA_READY           _ANIOC(AN_ADS2142_FIRST + 4)
+#define ANIOC_ADS2142_DO_SYSTEM_OFFSET_CALIB  _ANIOC(AN_ADS2142_FIRST + 5)
 
 /* ADS1242 REGISTER *********************************************************/
 
diff --git a/include/nuttx/analog/ioctl.h b/include/nuttx/analog/ioctl.h
new file mode 100644
index 00000000000..1364309958e
--- /dev/null
+++ b/include/nuttx/analog/ioctl.h
@@ -0,0 +1,94 @@
+/****************************************************************************
+ * include/nuttx/analog/ioctl.h
+ *
+ *   Copyright (C) 2017 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#ifndef __INCLUDE_NUTTX_ANALOG_IOCTL_H
+#define __INCLUDE_NUTTX_ANALOG_IOCTL_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/fs/ioctl.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* The analog driver sub-system uses the standard character driver framework.
+ * However, since the driver is a devices control interface rather than a
+ * data transfer interface, the majority of the functionality is implemented
+ * in driver ioctl calls.  Standard ioctl commands are listed below:
+ */
+
+/* DAC/ADC */
+
+#define ANIOC_TRIGGER     _ANIOC(0x0001)  /* Trigger one conversion
+                                           * IN: None
+                                           * OUT: None */
+
+#define AN_FIRST           0x0001         /* First required command */
+#define AN_NCMDS           1              /* Two required commands */
+
+/* User defined ioctl commands are also supported. These will be forwarded
+ * by the upper-half QE driver to the lower-half QE driver via the ioctl()
+ * method fo the QE lower-half interface.  However, the lower-half driver
+ * must reserve a block of commands as follows in order prevent IOCTL
+ * command numbers from overlapping.
+ */
+
+/* See include/nuttx/sensors/ads1242.h */
+
+#define AN_ADS2142_FIRST   (AN_FIRST + AN_NCMDS)
+#define AN_ADS2142_NCMDS   6
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __INCLUDE_NUTTX_ANALOG_IOCTL_H */
diff --git a/include/nuttx/fs/ioctl.h b/include/nuttx/fs/ioctl.h
index c8e76b3ca35..c5d25cd2120 100644
--- a/include/nuttx/fs/ioctl.h
+++ b/include/nuttx/fs/ioctl.h
@@ -242,21 +242,16 @@
 #define _TSIOCVALID(c)    (_IOC_TYPE(c)==_TSIOCBASE)
 #define _TSIOC(nr)        _IOC(_TSIOCBASE,nr)
 
-/* NuttX sensor ioctl definitions (see nuttx/sensor/xxx.h) ******************/
+/* NuttX sensor ioctl definitions (see nuttx/sensor/ioctl.h) ****************/
 
 #define _SNIOCVALID(c)    (_IOC_TYPE(c)==_SNIOCBASE)
 #define _SNIOC(nr)        _IOC(_SNIOCBASE,nr)
 
-/* Nuttx Analog (DAC/ADC_ ioctl commands ************************************/
+/* Nuttx Analog (DAC/ADC) ioctl commands (see nuttx/analog/ioctl.h **********/
 
 #define _ANIOCVALID(c)    (_IOC_TYPE(c)==_ANIOCBASE)
 #define _ANIOC(nr)        _IOC(_ANIOCBASE,nr)
 
-#define ANIOC_TRIGGER     _ANIOC(0x0001)  /* Trigger one conversion
-                                           * IN: None
-                                           * OUT: None */
-#define ANIOC_USER        0x0002          /* Device specific IOCTL commands
-                                           * may follow */
 /* NuttX PWM ioctl definitions (see nuttx/drivers/pwm.h) ********************/
 
 #define _PWMIOCVALID(c)   (_IOC_TYPE(c)==_PWMIOCBASE)
diff --git a/include/nuttx/sensors/qencoder.h b/include/nuttx/sensors/qencoder.h
index 7f269694863..33041f254e9 100644
--- a/include/nuttx/sensors/qencoder.h
+++ b/include/nuttx/sensors/qencoder.h
@@ -54,9 +54,9 @@
 
 /* IOCTL Commands ***********************************************************/
 /* The Quadrature Encode module uses a standard character driver framework.
- * However, since the driver is a devices control interface and not a data
- * transfer interface, the majority of the functionality is implemented in
- * driver ioctl calls.  The PWM ioctl commands are listed below:
+ * However, since the driver is a device control interface rather than a
+ * data transfer interface, the majority of the functionality is implemented
+ * in driver ioctl calls.  The PWM ioctl commands are listed below:
  *
  * QEIOC_POSITION - Get the current position from the encoder.
  *   Argument: int32_t pointer to the location to return the position.