diff --git a/drivers/ioexpander/icjx.c b/drivers/ioexpander/icjx.c
index 792e2dacb77..90fc94d3117 100644
--- a/drivers/ioexpander/icjx.c
+++ b/drivers/ioexpander/icjx.c
@@ -53,15 +53,29 @@
  * Private Types
  ****************************************************************************/
 
+struct icjx_callback_s
+{
+  ioe_pinset_t pinset;
+  ioe_callback_t function;
+  FAR void *arg;
+};
+
 struct icjx_dev_s
 {
   struct ioexpander_dev_s dev;         /* Nested structure to allow casting
                                         * as public gpio expander. */
   FAR struct icjx_config_s *config;    /* Board configuration data */
   FAR struct spi_dev_s *spi;           /* Saved SPI driver instance */
+
   uint16_t outpins;
   uint16_t outstate;
+  uint16_t irqpins;
   mutex_t lock;
+
+#ifdef CONFIG_IOEXPANDER_INT_ENABLE
+  struct work_s work;
+  struct icjx_callback_s callback;
+#endif
 };
 
 /****************************************************************************
@@ -100,6 +114,12 @@ static int icjx_multireadpin(FAR struct ioexpander_dev_s *dev,
                              FAR const uint8_t *pins, FAR bool *values,
                              int count);
 #endif
+#ifdef CONFIG_IOEXPANDER_INT_ENABLE
+static FAR void *icjx_attach(FAR struct ioexpander_dev_s *dev,
+                             ioe_pinset_t pinset, ioe_callback_t callback,
+                             FAR void *arg);
+static int icjx_detach(FAR struct ioexpander_dev_s *dev, FAR void *handle);
+#endif
 
 /****************************************************************************
  * Private Data
@@ -127,6 +147,10 @@ static const struct ioexpander_ops_s g_icjx_ops =
   , icjx_multireadpin
   , icjx_multireadpin
 #endif
+#ifdef CONFIG_IOEXPANDER_INT_ENABLE
+  , icjx_attach
+  , icjx_detach
+#endif
 };
 
 /****************************************************************************
@@ -463,15 +487,81 @@ static int icjx_option(FAR struct ioexpander_dev_s *dev, uint8_t pin,
                        int opt, FAR void *value)
 {
   /* TODO: Implementation of iC-JX options should be here. This includes
-   * setup of filters, ADC, interrupts etc. The right way to implement
+   * setup of filters, ADC etc. The right way to implement
    * this would probably be to introduce config structure to
    * include/nuttx/ioexpanders/icjx.h that the user could use for the
    * nibbles configuration.
+   *
+   * Currently only interrupts are implemented.
    */
 
-  gpiowarn("ERROR: iC-JX options are not yet implemted!\n");
+  FAR struct icjx_dev_s *priv = (FAR struct icjx_dev_s *)dev;
+  uint8_t data;
+  uint8_t reg;
+  int ret;
 
-  return -ENOTSUP;
+  DEBUGASSERT(priv != NULL && priv->config != NULL);
+
+  gpioinfo("Expander id=%02x pin=%u option=%u\n",
+           priv->config->id, pin, opt);
+
+  if (opt == IOEXPANDER_OPTION_INTCFG)
+    {
+      unsigned int ival = (unsigned int)((uintptr_t)value);
+      ret = nxmutex_lock(&priv->lock);
+      if (ret < 0)
+        {
+          return ret;
+        }
+
+      switch (ival)
+        {
+          case IOEXPANDER_VAL_HIGH:
+          case IOEXPANDER_VAL_LOW:
+          case IOEXPANDER_VAL_RISING:
+          case IOEXPANDER_VAL_FALLING:
+          case IOEXPANDER_VAL_BOTH:
+            priv->irqpins |= 1 << pin;
+            break;
+          case IOEXPANDER_VAL_DISABLE:
+            priv->irqpins &= ~(1 << pin);
+            break;
+          default:
+            nxmutex_unlock(&priv->lock);
+            return -EINVAL;
+        }
+
+      /* We have to modify ICJX_CHNG_INT_EN_A or ICJX_CHNG_INT_EN_B
+       * register.
+       */
+
+      if (pin < 8)
+        {
+          reg = ICJX_CHNG_INT_EN_A;
+          data = priv->irqpins & 0xff;
+        }
+      else
+        {
+          reg = ICJX_CHNG_INT_EN_B;
+          data = (priv->irqpins >> 8) & 0xff;
+        }
+
+      ret = icjx_write(priv, reg, data, ICJX_NOB1);
+      if (ret < 0)
+        {
+          gpioerr("Cannot write to %s register\n.",
+            reg == ICJX_CHNG_INT_EN_A ?
+            "ICJX_CHNG_INT_EN_A" : "ICJX_CHNG_INT_EN_B");
+        }
+
+      nxmutex_unlock(&priv->lock);
+    }
+  else
+    {
+      return -ENOTTY;
+    }
+
+  return ret;
 }
 
 /****************************************************************************
@@ -742,7 +832,7 @@ static int icjx_multireadpin(FAR struct ioexpander_dev_s *dev,
 
       if ((priv->outpins & (1 << pin)) != 0)
         {
-           values[i] = (priv->outstate & (1 << pin)) != 0;
+           values[i] = (bool)((priv->outstate & (1 << pin)) != 0);
         }
     }
 
@@ -755,13 +845,164 @@ static int icjx_multireadpin(FAR struct ioexpander_dev_s *dev,
 
   for (int i = 0; i < count; i++)
     {
-      values[i] = (data >> (pins[i] & 0xf)) & 1;
+      values[i] = (bool)((data >> (pins[i] & 0xf)) & 1);
     }
 
   return OK;
 }
 #endif /* CONFIG_IOEXPANDER_MULTIPIN */
 
+/****************************************************************************
+ * Name: icjx_attach
+ *
+ * Description:
+ *   Attach and enable a pin interrupt callback function.
+ *
+ * Input Parameters:
+ *   dev      - Device-specific state data
+ *   pinset   - The set of pin events that will generate the callback
+ *   callback - The pointer to callback function.  NULL will detach the
+ *              callback.
+ *   arg      - User-provided callback argument
+ *
+ * Returned Value:
+ *   A non-NULL handle value is returned on success.  This handle may be
+ *   used later to detach and disable the pin interrupt.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_IOEXPANDER_INT_ENABLE
+static FAR void *icjx_attach(FAR struct ioexpander_dev_s *dev,
+                             ioe_pinset_t pinset, ioe_callback_t callback,
+                             FAR void *arg)
+{
+  FAR struct icjx_dev_s *priv = (FAR struct icjx_dev_s *)dev;
+  FAR void *handle = NULL;
+  int ret;
+
+  /* Get exclusive access */
+
+  ret = nxmutex_lock(&priv->lock);
+  if (ret < 0)
+    {
+      return NULL;
+    }
+
+  if (priv->callback.function == NULL)
+    {
+      /* Yes.. use this entry */
+
+      priv->callback.pinset   = pinset;
+      priv->callback.function = callback;
+      priv->callback.arg      = arg;
+      handle                  = &priv->callback;
+    }
+
+  /* Add this callback to the table */
+
+  nxmutex_unlock(&priv->lock);
+  return handle;
+}
+
+/****************************************************************************
+ * Name: icjx_detach
+ *
+ * Description:
+ *   Detach and disable a pin interrupt callback function.
+ *
+ * Input Parameters:
+ *   dev      - Device-specific state data
+ *   handle   - The non-NULL opaque value return by pca9555_attch()
+ *
+ * Returned Value:
+ *   0 on success, else a negative error code
+ *
+ ****************************************************************************/
+
+static int icjx_detach(FAR struct ioexpander_dev_s *dev, FAR void *handle)
+{
+  FAR struct icjx_callback_s *cb =
+    (FAR struct icjx_callback_s *)handle;
+
+  cb->pinset = 0;
+  cb->function = NULL;
+  cb->arg  = NULL;
+  return OK;
+}
+
+/****************************************************************************
+ * Name: icjx_interrupt_worker
+ *
+ * Description:
+ *   Handle GPIO interrupt events (this function actually executes in the
+ *   context of the worker thread).
+ *
+ ****************************************************************************/
+
+static void icjx_interrupt_worker(void *arg)
+{
+  FAR struct icjx_dev_s *priv = (FAR struct icjx_dev_s *)arg;
+  uint8_t regaddr;
+  uint16_t change_of_input;
+  uint16_t isr;
+  ioe_pinset_t irq_match;
+  int ret;
+
+  /* Read interrupt status register */
+
+  icjx_read(priv, ICJX_INT_STATUS_A, &isr, ICJX_NOB2);
+  while (isr != 0)
+    {
+      if ((isr & ICJX_ISR_A_DCHI) != 0)
+        {
+          ret = icjx_read(priv, ICJX_CHNG_MSG_A, &change_of_input,
+                          ICJX_NOB2);
+          if (ret == OK)
+            {
+              irq_match = change_of_input & priv->callback.pinset;
+              if (irq_match != 0)
+                {
+                  /* Change of input.. perform the callback */
+
+                  priv->callback.function(&priv->dev, irq_match,
+                                          priv->callback.arg);
+                }
+            }
+        }
+
+      /* Clear interrupt and check ISR again */
+
+      icjx_write(priv, ICJX_CTRL_WORD_4, ICJX_CTRL_WORD_4_EOI, ICJX_NOB1);
+      icjx_read(priv, ICJX_INT_STATUS_A, &isr, ICJX_NOB2);
+    }
+}
+
+/****************************************************************************
+ * Name: icjx_interrupt
+ *
+ * Description:
+ *   Handle GPIO interrupt events (this function executes in the
+ *   context of the interrupt).
+ *
+ ****************************************************************************/
+
+static int icjx_interrupt(int irq, FAR void *context, FAR void *arg)
+{
+  FAR struct icjx_dev_s *priv = (FAR struct icjx_dev_s *)arg;
+
+  /* Create HP work to handle the interrupt. We do not want to do
+   * this in the interrupt handler because SPI communication speed.
+   */
+
+  DEBUGASSERT(work_available(&priv->work));
+  DEBUGVERIFY(work_queue(HPWORK, &priv->work, icjx_interrupt_worker,
+                        (void *)priv, 0));
+
+  return OK;
+}
+
+#endif
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -811,6 +1052,12 @@ FAR struct ioexpander_dev_s *icjx_initialize(FAR struct spi_dev_s *spi,
   priv->config   = config;
   priv->outpins  = 0;
   priv->outstate = 0;
+  priv->irqpins  = 0;
+
+#ifdef CONFIG_ICJX_INT_ENABLE
+  config->attach(config, icjx_interrupt, priv);
+  config->enable(config, true);
+#endif
 
   nxmutex_init(&priv->lock);
 
@@ -852,6 +1099,10 @@ FAR struct ioexpander_dev_s *icjx_initialize(FAR struct spi_dev_s *spi,
       goto err;
     }
 
+  /* Clear initial interrupts if any */
+
+  icjx_write(priv, ICJX_CTRL_WORD_4, ICJX_CTRL_WORD_4_EOI, ICJX_NOB1);
+
   return &priv->dev;
 
 err:
diff --git a/drivers/ioexpander/icjx.h b/drivers/ioexpander/icjx.h
index f0a736ce0e0..550924394c0 100644
--- a/drivers/ioexpander/icjx.h
+++ b/drivers/ioexpander/icjx.h
@@ -98,5 +98,29 @@
 #define ICJX_CTRL_WORD_2_NIOL   (1 << 3)
 #define ICJX_CTRL_WORD_2_NIOH   (1 << 7)
 
+/* Control Word 4 */
+
+#define ICJX_CTRL_WORD_4_EOI    (1 << 7)
+
+/* Interrupt Status Register A */
+
+#define ICJX_ISR_A_SCS   (1 << 0)
+#define ICJX_ISR_A_ET1   (1 << 1)
+#define ICJX_ISR_A_ET2   (1 << 2)
+#define ICJX_ISR_A_ISCI  (1 << 4)
+#define ICJX_ISR_A_IET1  (1 << 5)
+#define ICJX_ISR_A_IET2  (1 << 6)
+#define ICJX_ISR_A_DCHI  (1 << 7)
+
+/* Interrupt Status Register B */
+
+#define ICJX_ISR_B_USA   (1 << 0)
+#define ICJX_ISR_B_USD   (1 << 1)
+#define ICJX_ISR_B_EOC   (1 << 2)
+#define ICJX_ISR_B_IUSA  (1 << 4)
+#define ICJX_ISR_B_IUSD  (1 << 5)
+#define ICJX_ISR_B_ISD   (1 << 6)
+#define ICJX_ISR_B_IOEC  (1 << 7)
+
 #endif /* CONFIG_IOEXPANDER && CONFIG_IOEXPANDER_ICJX */
 #endif /* __DRIVERS_IOEXPANDER_ICJX_H */
diff --git a/include/nuttx/ioexpander/icjx.h b/include/nuttx/ioexpander/icjx.h
index 629a048019d..aa133a4495d 100644
--- a/include/nuttx/ioexpander/icjx.h
+++ b/include/nuttx/ioexpander/icjx.h
@@ -67,6 +67,20 @@ struct icjx_config_s
   uint8_t addr;         /* Device address (set by A(1:0) pins) */
   uint8_t mode;         /* SPI mode */
   uint32_t frequency;   /* SPI frequency */
+
+#ifdef CONFIG_IOEXPANDER_INT_ENABLE
+  /* IRQ/GPIO access callbacks.  These operations all hidden behind
+   * callbacks to isolate the iC-JX driver from differences in GPIO
+   * interrupt handling by varying boards and MCUs.
+   *
+   * attach  - Attach the iC-JX interrupt handler to the GPIO interrupt
+   * enable  - Enable or disable the GPIO interrupt
+   */
+
+  CODE int  (*attach)(FAR struct icjx_config_s *config, xcpt_t handler,
+                      FAR void *arg);
+  CODE void (*enable)(FAR struct icjx_config_s *config, bool enable);
+#endif
 };
 
 /****************************************************************************