Squashed commit of the following:

driver/ioexpander:  Add gpio_pin_unregister function to GPIO driver
  driver/ioexpander:  Add pinset struct to GPIO driver for interrupt pins larger than 64
  driver/ioexpander:  Initialize pintype/inttype when registering ioexpander device
  driver/ioexpander:  Add SETPINTYPE ioctl command to the GPIO driver

drivers/ioexpander/Kconfig

@@ -189,4 +189,15 @@ config GPIO_LOWER_HALF
 		Enable support for a lower half driver that provides GPIO driver
 		support for I/O expander pins.
 
+if GPIO_LOWER_HALF
+
+config GPIO_LOWER_HALF_INTTYPE
+	int "default interrupt type for GPIO_INTERRUPT_PIN pintype"
+	default 14
+	---help---
+		This is the default interrupt type (IOEXPANDER_VAL_BOTH) for
+		GPIO_INTERRUPT_PIN pintype in gplf driver register.
+
+endif
+
 endmenu # IO Expander/GPIO Support

drivers/ioexpander/gpio.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * drivers/ioexpander/gpio.c
  *
- *   Copyright (C) 2016 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2016, 2018 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -55,7 +55,7 @@
  * Private Function Prototypes
  ****************************************************************************/
 
-static int     gpio_handler(FAR struct gpio_dev_s *dev);
+static int     gpio_handler(FAR struct gpio_dev_s *dev, uint8_t pin);
 static int     gpio_open(FAR struct file *filep);
 static int     gpio_close(FAR struct file *filep);
 static ssize_t gpio_read(FAR struct file *filep, FAR char *buffer,
@@ -97,7 +97,7 @@ static const struct file_operations g_gpio_drvrops =
  *
  ****************************************************************************/
 
-static int gpio_handler(FAR struct gpio_dev_s *dev)
+static int gpio_handler(FAR struct gpio_dev_s *dev, uint8_t pin)
 {
   DEBUGASSERT(dev != NULL);
   (void)nxsig_kill(dev->gp_pid, dev->gp_signo);
@@ -296,6 +296,17 @@ static int gpio_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
           }
         break;
 
+      /* Command:     GPIOC_SETPINTYPE
+       * Description: Set the GPIO pin type.
+       * Argument:    The enum gpio_pintype_e type.
+       */
+
+      case GPIOC_SETPINTYPE:
+        {
+          ret = dev->gp_ops->go_setpintype(dev, arg);
+        }
+        break;
+
       /* Unrecognized command */
 
       default:
@@ -378,4 +389,54 @@ int gpio_pin_register(FAR struct gpio_dev_s *dev, int minor)
   return register_driver(devname, &g_gpio_drvrops, 0666, dev);
 }
 
+/****************************************************************************
+ * Name: gpio_pin_unregister
+ *
+ * Description:
+ *   Unregister GPIO pin device driver.
+ *
+ *   - Input pin types will be registered at /dev/gpinN
+ *   - Output pin types will be registered at /dev/gpoutN
+ *   - Interrupt pin types will be registered at /dev/gpintN
+ *
+ *   Where N is the provided minor number in the range of 0-99.
+ *
+ *
+ ****************************************************************************/
+
+void gpio_pin_unregister(FAR struct gpio_dev_s *dev, int minor)
+{
+  FAR const char *fmt;
+  char devname[16];
+
+  switch (dev->gp_pintype)
+    {
+      case GPIO_INPUT_PIN:
+        {
+          fmt = "/dev/gpin%u";
+        }
+        break;
+
+      case GPIO_OUTPUT_PIN:
+        {
+          fmt = "/dev/gpout%u";
+        }
+        break;
+
+      case GPIO_INTERRUPT_PIN:
+        {
+          fmt = "/dev/gpint%u";
+        }
+        break;
+
+      default:
+        return;
+    }
+
+  snprintf(devname, 16, fmt, (unsigned int)minor);
+  gpioinfo("Unregistering %s\n", devname);
+
+  (void)unregister_driver(devname);
+}
+
 #endif /* CONFIG_DEV_GPIO */

drivers/ioexpander/gpio_lower_half.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * drivers/ioexpander/gpio_lower_half.c
  *
- *   Copyright (C) 2016 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2016, 2018 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -88,6 +88,8 @@ static int gplh_write(FAR struct gpio_dev_s *gpio, bool value);
 static int gplh_attach(FAR struct gpio_dev_s *gpio, pin_interrupt_t callback);
 static int gplh_enable(FAR struct gpio_dev_s *gpio, bool enable);
 #endif
+static int gplh_setpintype(FAR struct gpio_dev_s *gpio,
+                           enum gpio_pintype_e pintype);
 
 /****************************************************************************
  * Private Data
@@ -106,6 +108,22 @@ static const struct gpio_operations_s g_gplh_ops =
   NULL,        /* attach */
   NULL,        /* enable */
 #endif
+  gplh_setpintype,
+};
+
+/* REVISIT:  The following violates the NuttX coding standard requirement
+ * for C89 compatibility.
+ */
+
+static const uint32_t g_gplh_inttype[] =
+{
+  [GPIO_INPUT_PIN]              = IOEXPANDER_VAL_DISABLE,
+  [GPIO_INTERRUPT_PIN]          = CONFIG_GPIO_LOWER_HALF_INTTYPE,
+  [GPIO_INTERRUPT_HIGH_PIN]     = IOEXPANDER_VAL_HIGH,
+  [GPIO_INTERRUPT_LOW_PIN]      = IOEXPANDER_VAL_LOW,
+  [GPIO_INTERRUPT_RISING_PIN]   = IOEXPANDER_VAL_RISING,
+  [GPIO_INTERRUPT_FALLING_PIN]  = IOEXPANDER_VAL_FALLING,
+  [GPIO_INTERRUPT_BOTH_PIN]     = IOEXPANDER_VAL_BOTH,
 };
 
 /****************************************************************************
@@ -135,7 +153,7 @@ static int gplh_handler(FAR struct ioexpander_dev_s *ioe,
    * upper half GPIO driver via its callback.
    */
 
-  return priv->callback(&priv->gpio);
+  return priv->callback(&priv->gpio, priv->pin);
 }
 #endif
 
@@ -258,7 +276,11 @@ static int gplh_enable(FAR struct gpio_dev_s *gpio, bool enable)
 
       else if (priv->handle == NULL)
         {
+#if CONFIG_IOEXPANDER_NPINS <= 64
           ioe_pinset_t pinset = ((ioe_pinset_t)1 << priv->pin);
+#else
+          ioe_pinset_t pinset = ((ioe_pinset_t)priv->pin);
+#endif
 
           /* We have a callback and the callback is not yet attached.
            * do it now.
@@ -302,6 +324,39 @@ static int gplh_enable(FAR struct gpio_dev_s *gpio, bool enable)
 }
 #endif
 
+/****************************************************************************
+ * Name: gplh_setpintype
+ *
+ * Description:
+ *   Set I/O expander pin to an appointed gpiopintype
+ *
+ ****************************************************************************/
+
+static int gplh_setpintype(FAR struct gpio_dev_s *gpio, enum gpio_pintype_e pintype)
+{
+  FAR struct gplh_dev_s *priv = (FAR struct gplh_dev_s *)gpio;
+  FAR struct ioexpander_dev_s *ioe = priv->ioe;
+  uint8_t pin = priv->pin;
+
+  if (pintype >= GPIO_NPINTYPES)
+    {
+      return -EINVAL;
+    }
+  else if (pintype == GPIO_OUTPUT_PIN)
+    {
+      IOEXP_SETDIRECTION(ioe, pin, IOEXPANDER_DIRECTION_OUT);
+    }
+  else
+    {
+      IOEXP_SETDIRECTION(ioe, pin, IOEXPANDER_DIRECTION_IN);
+      IOEXP_SETOPTION(ioe, pin, IOEXPANDER_OPTION_INTCFG,
+                      (FAR void *)g_gplh_inttype[pintype]);
+    }
+
+  gpio->gp_pintype = pintype;
+  return OK;
+}
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -360,6 +415,17 @@ int gpio_lower_half(FAR struct ioexpander_dev_s *ioe, unsigned int pin,
   gpio->gp_pintype = (uint8_t)pintype;
   gpio->gp_ops     = &g_gplh_ops;
 
+  if (pintype == GPIO_OUTPUT_PIN)
+    {
+      IOEXP_SETDIRECTION(ioe, pin, IOEXPANDER_DIRECTION_OUT);
+    }
+  else
+    {
+      IOEXP_SETDIRECTION(ioe, pin, IOEXPANDER_DIRECTION_IN);
+      IOEXP_SETOPTION(ioe, pin, IOEXPANDER_OPTION_INTCFG,
+                      (FAR void *)g_gplh_inttype[pintype]);
+    }
+
   /* Register the GPIO driver */
 
   ret = gpio_pin_register(gpio, minor);

include/nuttx/ioexpander/gpio.h

@@ -75,6 +75,11 @@
  * Command:     GPIOC_UNREGISTER
  * Description: Stop receiving signals for pin interrupts.
  * Argument:    None.
+ *
+ * Command:     GPIOC_SETPINTYPE
+ * Description: Set the GPIO pin type.
+ * Argument:    The enum gpio_pintype_e type.
+ *
  */
 
 #define GPIOC_WRITE      _GPIOC(1)
@@ -82,6 +87,7 @@
 #define GPIOC_PINTYPE    _GPIOC(3)
 #define GPIOC_REGISTER   _GPIOC(4)
 #define GPIOC_UNREGISTER _GPIOC(5)
+#define GPIOC_SETPINTYPE _GPIOC(6)
 
 /****************************************************************************
  * Public Types
@@ -94,6 +100,11 @@ enum gpio_pintype_e
   GPIO_INPUT_PIN = 0,
   GPIO_OUTPUT_PIN,
   GPIO_INTERRUPT_PIN,
+  GPIO_INTERRUPT_HIGH_PIN,
+  GPIO_INTERRUPT_LOW_PIN,
+  GPIO_INTERRUPT_RISING_PIN,
+  GPIO_INTERRUPT_FALLING_PIN,
+  GPIO_INTERRUPT_BOTH_PIN,
   GPIO_NPINTYPES
 };
 
@@ -110,6 +121,7 @@ typedef CODE int (*pin_interrupt_t)(FAR struct gpio_dev_s *dev);
  *     for other pin types may be NULL.
  *   - go_attach and gp_eanble.  Required only the GPIO_INTERRUPT_PIN pin
  *     type.  Unused for other pin types may be NULL.
+ *   - go_setpinytype.  Required for all all pin types.
  */
 
 struct gpio_dev_s;
@@ -122,6 +134,8 @@ struct gpio_operations_s
   CODE int (*go_attach)(FAR struct gpio_dev_s *dev,
                         pin_interrupt_t callback);
   CODE int (*go_enable)(FAR struct gpio_dev_s *dev, bool enable);
+  CODE int (*go_setpintype)(FAR struct gpio_dev_s *dev,
+                            enum gpio_pintype_e pintype);
 };
 
 /* Pin interface definition.  Must lie in writable memory. */
@@ -177,6 +191,23 @@ extern "C"
 
 int gpio_pin_register(FAR struct gpio_dev_s *dev, int minor);
 
+/****************************************************************************
+ * Name: gpio_pin_unregister
+ *
+ * Description:
+ *   Unregister GPIO pin device driver.
+ *
+ *   - Input pin types will be registered at /dev/gpinN
+ *   - Output pin types will be registered at /dev/gpoutN
+ *   - Interrupt pin types will be registered at /dev/gpintN
+ *
+ *   Where N is the provided minor number in the range of 0-99.
+ *
+ *
+ ****************************************************************************/
+
+void gpio_pin_unregister(FAR struct gpio_dev_s *dev, int minor);
+
 /****************************************************************************
  * Name: gpio_lower_half
  *

include/nuttx/ioexpander/ioexpander.h

@@ -1,7 +1,7 @@
 /****************************************************************************
  * include/nuttx/ioexpander/ioexpander.h
  *
- *   Copyright (C) 2015-2016 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2015-2016, 2018 Gregory Nutt. All rights reserved.
  *   Author: Sebastien Lorquet <sebastien@lorquet.fr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -41,6 +41,7 @@
  ****************************************************************************/
 
 #include <nuttx/config.h>
+#include <stdbool.h>
 #include <stdint.h>
 
 #ifdef CONFIG_IOEXPANDER
@@ -55,10 +56,6 @@
 #  define CONFIG_IOEXPANDER_NPINS 16
 #endif
 
-#if CONFIG_IOEXPANDER_NPINS > 64
-#  error No support for devices with more than 64 pins
-#endif
-
 /* Pin definitions **********************************************************/
 
 #define IOEXPANDER_DIRECTION_IN    0
@@ -101,7 +98,7 @@
  *
  ****************************************************************************/
 
-#define IOEXP_SETDIRECTION(dev,pin,dir)  ((dev)->ops->ioe_direction(dev,pin,dir))
+#define IOEXP_SETDIRECTION(dev,pin,dir) ((dev)->ops->ioe_direction(dev,pin,dir))
 
 /****************************************************************************
  * Name: IOEXP_SETOPTION
@@ -293,7 +290,11 @@
  * Public Types
  ****************************************************************************/
 
-/* This type represents a bitmap of pins */
+/* This type represents a bitmap of pins
+ *
+ * For IOE NPINS greater than 64, ioe_pinset_t represent one interrupt pin
+ * number instead of a bitmap of pins.
+ */
 
 #if CONFIG_IOEXPANDER_NPINS <= 8
 typedef uint8_t ioe_pinset_t;
@@ -301,8 +302,10 @@ typedef uint8_t ioe_pinset_t;
 typedef uint16_t ioe_pinset_t;
 #elif CONFIG_IOEXPANDER_NPINS <= 32
 typedef uint32_t ioe_pinset_t;
-#else /* if CONFIG_IOEXPANDER_NPINS <= 64 */
+#elif CONFIG_IOEXPANDER_NPINS <= 64
 typedef uint64_t ioe_pinset_t;
+#else
+typedef uint8_t ioe_pinset_t;
 #endif
 
 #ifdef CONFIG_IOEXPANDER_INT_ENABLE