Add GPIO IRQ logic

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@1779 42af7a65-404d-4744-a932-0658087f49c3

5 files changed, 567 insertions, 3 deletions

diff --git a/nuttx/arch/arm/include/lm3s/irq.h b/nuttx/arch/arm/include/lm3s/irq.h
index 6714c909a..68df2e4b6 100644
--- a/nuttx/arch/arm/include/lm3s/irq.h
+++ b/nuttx/arch/arm/include/lm3s/irq.h
@@ -46,6 +46,7 @@
 
 #include <nuttx/config.h>
 #include <sys/types.h>
+#include <nuttx/irq.h>
 
 /************************************************************************************
  * Definitions
@@ -121,6 +122,124 @@
 
 #define NR_IRQS              (60) /* Really only 43 */
 
+/* GPIO IRQs -- Note that support for individual GPIO ports can
+ * be disabled in order to reduce the size of the implemenation.
+ */
+
+#ifndef CONFIG_LM3S_DISABLE_GPIOA_IRQS
+#  define LM3S_IRQ_GPIOA_0 (NR_IRQS + 0)
+#  define LM3S_IRQ_GPIOA_1 (NR_IRQS + 1)
+#  define LM3S_IRQ_GPIOA_2 (NR_IRQS + 2)
+#  define LM3S_IRQ_GPIOA_3 (NR_IRQS + 3)
+#  define LM3S_IRQ_GPIOA_4 (NR_IRQS + 4)
+#  define LM3S_IRQ_GPIOA_5 (NR_IRQS + 5)
+#  define LM3S_IRQ_GPIOA_6 (NR_IRQS + 6)
+#  define LM3S_IRQ_GPIOA_7 (NR_IRQS + 7)
+#  define _NGPIOAIRQS      (NR_IRQS + 8)
+#else
+#  define _NGPIOAIRQS      NR_IRQS
+#endif
+
+#ifndef CONFIG_LM3S_DISABLE_GPIOB_IRQS
+#  define LM3S_IRQ_GPIOB_0 (_NGPIOAIRQS + 0)
+#  define LM3S_IRQ_GPIOB_1 (_NGPIOAIRQS + 1)
+#  define LM3S_IRQ_GPIOB_2 (_NGPIOAIRQS + 2)
+#  define LM3S_IRQ_GPIOB_3 (_NGPIOAIRQS + 3)
+#  define LM3S_IRQ_GPIOB_4 (_NGPIOAIRQS + 4)
+#  define LM3S_IRQ_GPIOB_5 (_NGPIOAIRQS + 5)
+#  define LM3S_IRQ_GPIOB_6 (_NGPIOAIRQS + 6)
+#  define LM3S_IRQ_GPIOB_7 (_NGPIOAIRQS + 7)
+#  define _NGPIOBIRQS      (_NGPIOAIRQS + 8)
+#else
+#  define _NGPIOBIRQS      _NGPIOAIRQS
+#endif
+
+#ifndef CONFIG_LM3S_DISABLE_GPIOC_IRQS
+#  define LM3S_IRQ_GPIOC_0 (_NGPIOBIRQS + 0)
+#  define LM3S_IRQ_GPIOC_1 (_NGPIOBIRQS + 1)
+#  define LM3S_IRQ_GPIOC_2 (_NGPIOBIRQS + 2)
+#  define LM3S_IRQ_GPIOC_3 (_NGPIOBIRQS + 3)
+#  define LM3S_IRQ_GPIOC_4 (_NGPIOBIRQS + 4)
+#  define LM3S_IRQ_GPIOC_5 (_NGPIOBIRQS + 5)
+#  define LM3S_IRQ_GPIOC_6 (_NGPIOBIRQS + 6)
+#  define LM3S_IRQ_GPIOC_7 (_NGPIOBIRQS + 7)
+#  define _NGPIOCIRQS      (_NGPIOBIRQS + 8)
+#else
+#  define _NGPIOCIRQS      _NGPIOBIRQS
+#endif
+
+#ifndef CONFIG_LM3S_DISABLE_GPIOD_IRQS
+#  define LM3S_IRQ_GPIOD_0 (_NGPIOCIRQS + 0)
+#  define LM3S_IRQ_GPIOD_1 (_NGPIOCIRQS + 1)
+#  define LM3S_IRQ_GPIOD_2 (_NGPIOCIRQS + 2)
+#  define LM3S_IRQ_GPIOD_3 (_NGPIOCIRQS + 3)
+#  define LM3S_IRQ_GPIOD_4 (_NGPIOCIRQS + 4)
+#  define LM3S_IRQ_GPIOD_5 (_NGPIOCIRQS + 5)
+#  define LM3S_IRQ_GPIOD_6 (_NGPIOCIRQS + 6)
+#  define LM3S_IRQ_GPIOD_7 (_NGPIOCIRQS + 7)
+#  define _NGPIODIRQS      (_NGPIOCIRQS + 8)
+#else
+#  define _NGPIODIRQS      _NGPIOCIRQS
+#endif
+
+#ifndef CONFIG_LM3S_DISABLE_GPIOE_IRQS
+#  define LM3S_IRQ_GPIOE_0 (_NGPIODIRQS + 0)
+#  define LM3S_IRQ_GPIOE_1 (_NGPIODIRQS + 1)
+#  define LM3S_IRQ_GPIOE_2 (_NGPIODIRQS + 2)
+#  define LM3S_IRQ_GPIOE_3 (_NGPIODIRQS + 3)
+#  define LM3S_IRQ_GPIOE_4 (_NGPIODIRQS + 4)
+#  define LM3S_IRQ_GPIOE_5 (_NGPIODIRQS + 5)
+#  define LM3S_IRQ_GPIOE_6 (_NGPIODIRQS + 6)
+#  define LM3S_IRQ_GPIOE_7 (_NGPIODIRQS + 7)
+#  define _NGPIOEIRQS      (_NGPIODIRQS + 8)
+#else
+#  define _NGPIOEIRQS      _NGPIODIRQS
+#endif
+
+#ifndef CONFIG_LM3S_DISABLE_GPIOF_IRQS
+#  define LM3S_IRQ_GPIOF_0 (_NGPIOEIRQS + 0)
+#  define LM3S_IRQ_GPIOF_1 (_NGPIOEIRQS + 1)
+#  define LM3S_IRQ_GPIOF_2 (_NGPIOEIRQS + 2)
+#  define LM3S_IRQ_GPIOF_3 (_NGPIOEIRQS + 3)
+#  define LM3S_IRQ_GPIOF_4 (_NGPIOEIRQS + 4)
+#  define LM3S_IRQ_GPIOF_5 (_NGPIOEIRQS + 5)
+#  define LM3S_IRQ_GPIOF_6 (_NGPIOEIRQS + 6)
+#  define LM3S_IRQ_GPIOF_7 (_NGPIOEIRQS + 7)
+#  define _NGPIOFIRQS      (_NGPIOEIRQS + 8)
+#else
+#  define _NGPIOFIRQS      _NGPIOEIRQS
+#endif
+
+#ifndef CONFIG_LM3S_DISABLE_GPIOG_IRQS
+#  define LM3S_IRQ_GPIOG_0 (_NGPIOFIRQS + 0)
+#  define LM3S_IRQ_GPIOG_1 (_NGPIOFIRQS + 1)
+#  define LM3S_IRQ_GPIOG_2 (_NGPIOFIRQS + 2)
+#  define LM3S_IRQ_GPIOG_3 (_NGPIOFIRQS + 3)
+#  define LM3S_IRQ_GPIOG_4 (_NGPIOFIRQS + 4)
+#  define LM3S_IRQ_GPIOG_5 (_NGPIOFIRQS + 5)
+#  define LM3S_IRQ_GPIOG_6 (_NGPIOFIRQS + 6)
+#  define LM3S_IRQ_GPIOG_7 (_NGPIOFIRQS + 7)
+#  define _NGPIOGIRQS      (_NGPIOFIRQS + 8)
+#else
+#  define _NGPIOGIRQS      _NGPIOFIRQS
+#endif
+
+#ifndef CONFIG_LM3S_DISABLE_GPIOH_IRQS
+#  define LM3S_IRQ_GPIOH_0 (_NGPIOGIRQS + 0)
+#  define LM3S_IRQ_GPIOH_1 (_NGPIOGIRQS + 1)
+#  define LM3S_IRQ_GPIOH_2 (_NGPIOGIRQS + 2)
+#  define LM3S_IRQ_GPIOH_3 (_NGPIOGIRQS + 3)
+#  define LM3S_IRQ_GPIOH_4 (_NGPIOGIRQS + 4)
+#  define LM3S_IRQ_GPIOH_5 (_NGPIOGIRQS + 5)
+#  define LM3S_IRQ_GPIOH_6 (_NGPIOGIRQS + 6)
+#  define LM3S_IRQ_GPIOH_7 (_NGPIOGIRQS + 7)
+#  define _NGPIOHIRQS      (_NGPIOGIRQS + 8)
+#else
+#  define _NGPIOHIRQS      _NGPIOGIRQS
+#endif
+
+#define NR_GPIO_IRQS       (_NGPIOHIRQS - NR_IRQS)
+
 /************************************************************************************
  * Public Types
  ************************************************************************************/
@@ -141,6 +260,37 @@ extern "C" {
  * Public Functions
  ************************************************************************************/
 
+/****************************************************************************
+ * Name: gpio_irqattach
+ *
+ * Description:
+ *   Attach the interrupt handler 'isr' to the GPIO IRQ 'irq'
+ *
+ ****************************************************************************/
+
+EXTERN int gpio_irqattach(int irq, xcpt_t isr);
+#define gpio_irqdetach(isr) gpio_irqattach(isr, NULL)
+
+/****************************************************************************
+ * Name: gpio_irqenable
+ *
+ * Description:
+ *   Enable the GPIO IRQ specified by 'irq'
+ *
+ ****************************************************************************/
+
+EXTERN void gpio_irqenable(int irq);
+
+/****************************************************************************
+ * Name: gpio_irqdisable
+ *
+ * Description:
+ *   Disable the GPIO IRQ specified by 'irq'
+ *
+ ****************************************************************************/
+
+EXTERN void gpio_irqdisable(int irq);
+
 #undef EXTERN
 #ifdef __cplusplus
 }
diff --git a/nuttx/arch/arm/src/lm3s/Make.defs b/nuttx/arch/arm/src/lm3s/Make.defs
index 9e9ea238e..f033f8826 100644
--- a/nuttx/arch/arm/src/lm3s/Make.defs
+++ b/nuttx/arch/arm/src/lm3s/Make.defs
@@ -47,7 +47,8 @@ CMN_CSRCS	= up_allocateheap.c up_assert.c up_blocktask.c up_copystate.c \
 
 CHIP_ASRCS	= lm3s_context.S
 CHIP_CSRCS	= lm3s_start.c lm3s_syscontrol.c lm3s_irq.c lm3s_pendsv.c \
-		  lm3s_gpio.c lm3s_timerisr.c lm3s_lowputc.c lm3s_serial.c
+		  lm3s_gpio.c lm3s_gpioirq.c lm3s_timerisr.c lm3s_lowputc.c \
+		  lm3s_serial.c
 
 ifdef CONFIG_NET
 CHIP_CSRCS	+= lm3s_ethernet.c
diff --git a/nuttx/arch/arm/src/lm3s/lm3s_gpioirq.c b/nuttx/arch/arm/src/lm3s/lm3s_gpioirq.c
new file mode 100644
index 000000000..590e0d753
--- /dev/null
+++ b/nuttx/arch/arm/src/lm3s/lm3s_gpioirq.c
@@ -0,0 +1,394 @@
+/****************************************************************************
+ * arch/arm/src/lm3s/lm3s_gpioirq.c
+ * arch/arm/src/chip/lm3s_gpioirq.c
+ *
+ *   Copyright (C) 2009 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * 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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <sys/types.h>
+
+#include <string.h>
+#include <assert.h>
+#include <debug.h>
+
+#include <arch/irq.h>
+
+#include "up_arch.h"
+#include "os_internal.h"
+#include "irq_internal.h"
+#include "lm3s_internal.h"
+
+/****************************************************************************
+ * Private Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* A table of handlers for each GPIO interrupt */
+
+static FAR xcpt_t g_gpioirqvector[NR_GPIO_IRQS];
+
+/* A table that maps a GPIO group to a GPIO base address.  Overly complicated
+ * be we support disabling interrupt support for arbitrary ports
+ */
+
+static const uint32 g_gpiobase[] =
+{
+#ifndef CONFIG_LM3S_DISABLE_GPIOA_IRQS
+   LM3S_GPIOA_BASE,
+#endif
+#ifndef CONFIG_LM3S_DISABLE_GPIOB_IRQS
+  LM3S_GPIOB_BASE,
+#endif
+#ifndef CONFIG_LM3S_DISABLE_GPIOC_IRQS
+  LM3S_GPIOC_BASE,
+#endif
+#ifndef CONFIG_LM3S_DISABLE_GPIOD_IRQS
+  LM3S_GPIOD_BASE,
+#endif
+#ifndef CONFIG_LM3S_DISABLE_GPIOE_IRQS
+  LM3S_GPIOE_BASE,
+#endif
+#ifndef CONFIG_LM3S_DISABLE_GPIOF_IRQS
+  LM3S_GPIOF_BASE,
+#endif
+#ifndef CONFIG_LM3S_DISABLE_GPIOG_IRQS
+  LM3S_GPIOG_BASE,
+#endif
+#ifndef CONFIG_LM3S_DISABLE_GPIOH_IRQS
+  LM3S_GPIOH_BASE,
+#endif
+};
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: lm3s_gpiobaseaddress
+ *
+ * Description:
+ *   Given a GPIO enumeration value, return the base address of the
+ *   associated GPIO registers.
+ *
+ ****************************************************************************/
+
+static inline uint32 lm3s_gpiobaseaddress(unsigned int port)
+{
+  return g_gpiobase[port >> 3];
+}
+
+/****************************************************************************
+ * Name: lm3s_gpio*handler
+ *
+ * Description:
+ *   Handle interrupts on each enabled GPIO port
+ *
+ ****************************************************************************/
+
+static int lm3s_gpiohandler(uint32 regbase, int irqbase, void *context)
+{
+  uint32 mis;
+  int irq;
+  int pin;
+
+  /* Handle each pending GPIO interrupt.  "The GPIO MIS register is the masked
+   * interrupt status register. Bits read High in GPIO MIS reflect the status
+   * of input lines triggering an interrupt. Bits read as Low indicate that
+   * either no interrupt has been generated, or the interrupt is masked."
+   */
+
+  mis = getreg32(regbase + LM3S_GPIO_MIS_OFFSET) & 0xff;
+
+  /* Clear all GPIO interrupts that we are going to process.  "The GPIO ICR
+   * register is the interrupt clear register. Writing a 1 to a bit in this
+   * register clears the corresponding interrupt edge detection logic register.
+   * Writing a 0 has no effect."
+   */
+
+  putreg32(mis, regbase + LM3S_GPIO_ICR_OFFSET);
+
+  /* Now process each IRQ pending in the MIS */
+
+  for (pin = 0; pin < 8 && mis != 0; pin++, mis >>= 1)
+    {
+      if ((mis & 1) != 0)
+        {
+          irq = irqbase + pin;
+          g_gpioirqvector[irq - NR_IRQS](irq, context);
+        }
+    }
+  return OK;
+}
+
+#ifndef CONFIG_LM3S_DISABLE_GPIOA_IRQS
+static int lm3s_gpioahandler(int irq, FAR void *context)
+{
+  return lm3s_gpiohandler(LM3S_GPIOA_BASE, LM3S_IRQ_GPIOA_0, context);
+}
+#endif
+
+#ifndef CONFIG_LM3S_DISABLE_GPIOB_IRQS
+static int lm3s_gpiobhandler(int irq, FAR void *context)
+{
+  return lm3s_gpiohandler(LM3S_GPIOB_BASE, LM3S_IRQ_GPIOB_0, context);
+}
+#endif
+
+#ifndef CONFIG_LM3S_DISABLE_GPIOC_IRQS
+static int lm3s_gpiochandler(int irq, FAR void *context)
+{
+  return lm3s_gpiohandler(LM3S_GPIOC_BASE, LM3S_IRQ_GPIOC_0, context);
+}
+#endif
+
+#ifndef CONFIG_LM3S_DISABLE_GPIOD_IRQS
+static int lm3s_gpiodhandler(int irq, FAR void *context)
+{
+  return lm3s_gpiohandler(LM3S_GPIOD_BASE, LM3S_IRQ_GPIOD_0, context);
+}
+#endif
+
+#ifndef CONFIG_LM3S_DISABLE_GPIOE_IRQS
+static int lm3s_gpioehandler(int irq, FAR void *context)
+{
+  return lm3s_gpiohandler(LM3S_GPIOE_BASE, LM3S_IRQ_GPIOE_0, context);
+}
+#endif
+
+#ifndef CONFIG_LM3S_DISABLE_GPIOF_IRQS
+static int lm3s_gpiofhandler(int irq, FAR void *context)
+{
+  return lm3s_gpiohandler(LM3S_GPIOF_BASE, LM3S_IRQ_GPIOF_0, context);
+}
+#endif
+
+#ifndef CONFIG_LM3S_DISABLE_GPIOG_IRQS
+static int lm3s_gpioghandler(int irq, FAR void *context)
+{
+  return lm3s_gpiohandler(LM3S_GPIOG_BASE, LM3S_IRQ_GPIOG_0, context);
+}
+#endif
+
+#ifndef CONFIG_LM3S_DISABLE_GPIOH_IRQS
+static int lm3s_gpiohhandler(int irq, FAR void *context)
+{
+  return lm3s_gpiohandler(LM3S_GPIOH_BASE, LM3S_IRQ_GPIOH_0, context);
+}
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: gpio_irqinitialize
+ *
+ * Description:
+ *   Initialize all vectors to the unexpected interrupt handler
+ *
+ ****************************************************************************/
+
+int gpio_irqinitialize(void)
+{
+  int i;
+
+  /* Point all interrupt vectors to the unexpected interrupt */
+
+  for (i = 0; i < NR_GPIO_IRQS; i++)
+    {
+      g_gpioirqvector[i] = irq_unexpected_isr;
+    }
+
+  /* Then attach all GPIO interrupt handlers */
+
+#ifndef CONFIG_LM3S_DISABLE_GPIOA_IRQS
+  irq_attach(LM3S_IRQ_GPIOA, lm3s_gpioahandler);
+#endif
+#ifndef CONFIG_LM3S_DISABLE_GPIOB_IRQS
+  irq_attach(LM3S_IRQ_GPIOB, lm3s_gpiobhandler);
+#endif
+#ifndef CONFIG_LM3S_DISABLE_GPIOC_IRQS
+  irq_attach(LM3S_IRQ_GPIOC, lm3s_gpiochandler);
+#endif
+#ifndef CONFIG_LM3S_DISABLE_GPIOD_IRQS
+  irq_attach(LM3S_IRQ_GPIOD, lm3s_gpiodhandler);
+#endif
+#ifndef CONFIG_LM3S_DISABLE_GPIOE_IRQS
+  irq_attach(LM3S_IRQ_GPIOE, lm3s_gpioehandler);
+#endif
+#ifndef CONFIG_LM3S_DISABLE_GPIOF_IRQS
+  irq_attach(LM3S_IRQ_GPIOF, lm3s_gpiofhandler);
+#endif
+#ifndef CONFIG_LM3S_DISABLE_GPIOG_IRQS
+  irq_attach(LM3S_IRQ_GPIOG, lm3s_gpioghandler);
+#endif
+#ifndef CONFIG_LM3S_DISABLE_GPIOH_IRQS
+  irq_attach(LM3S_IRQ_GPIOH, lm3s_gpiohhandler);
+#endif
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: gpio_irqattach
+ *
+ * Description:
+ *   Attach in GPIO interrupt to the provide 'isr'
+ *
+ ****************************************************************************/
+
+int gpio_irqattach(int irq, xcpt_t isr)
+{
+  irqstate_t flags;
+  int        gpioirq = irq - NR_IRQS;
+  int        ret     = ERROR;
+
+  if ((unsigned)gpioirq < NR_GPIO_IRQS)
+    {
+      flags = irqsave();
+
+      /* If the new ISR is NULL, then the ISR is being detached.
+       * In this case, disable the ISR and direct any interrupts
+       * to the unexpected interrupt handler.
+       */
+
+      if (isr == NULL)
+        {
+#ifndef CONFIG_ARCH_NOINTC
+           gpio_irqdisable(gpioirq);
+#endif
+           isr = irq_unexpected_isr;
+        }
+
+      /* Save the new ISR in the table. */
+
+      g_irqvector[gpioirq] = isr;
+      irqrestore(flags);
+      ret = OK;
+    }
+  return ret;
+}
+
+/****************************************************************************
+ * Name: gpio_irqenable
+ *
+ * Description:
+ *   Enable the GPIO IRQ specified by 'irq'
+ *
+ ****************************************************************************/
+
+void gpio_irqenable(int irq)
+{
+  irqstate_t flags;
+  int        gpioirq = irq - NR_IRQS;
+  uint32     base;
+  uint32     regval;
+  int        pin;
+  int        ret     = ERROR;
+
+  if ((unsigned)gpioirq < NR_GPIO_IRQS)
+    {
+      /* Get the base address of the GPIO module associated with this IRQ */
+
+      base = lm3s_gpiobaseaddress(gpioirq);
+      pin  = (1 << (gpioirq & 7));
+
+      /* Disable the GPIO interrupt. "The GPIO IM register is the interrupt
+       * mask register. Bits set to High in GPIO IM allow the corresponding
+       * pins to trigger their individual interrupts and the combined GPIO INTR
+       * line. Clearing a bit disables interrupt triggering on that pin. All
+       * bits are cleared by a reset.
+       */
+
+      flags   = irqsave();
+      regval  = getreg32(base + LM3S_GPIO_IM_OFFSET);
+      regval |= pin;
+      putreg32(regval, base + LM3S_GPIO_IM_OFFSET);
+      irqrestore(flags);
+      ret = OK;
+    }
+  return ret;
+}
+
+/****************************************************************************
+ * Name: gpio_irqdisable
+ *
+ * Description:
+ *   Disable the GPIO IRQ specified by 'irq'
+ *
+ ****************************************************************************/
+
+void gpio_irqdisable(int irq)
+{
+  irqstate_t flags;
+  int        gpioirq = irq - NR_IRQS;
+  uint32     base;
+  uint32     regval;
+  int        pin;
+  int        ret     = ERROR;
+
+  if ((unsigned)gpioirq < NR_GPIO_IRQS)
+    {
+      /* Get the base address of the GPIO module associated with this IRQ */
+
+      base = lm3s_gpiobaseaddress(gpioirq);
+      pin  = (1 << (gpioirq & 7));
+
+      /* Disable the GPIO interrupt. "The GPIO IM register is the interrupt
+       * mask register. Bits set to High in GPIO IM allow the corresponding
+       * pins to trigger their individual interrupts and the combined GPIO INTR
+       * line. Clearing a bit disables interrupt triggering on that pin. All
+       * bits are cleared by a reset.
+       */
+
+      flags   = irqsave();
+      regval  = getreg32(base + LM3S_GPIO_IM_OFFSET);
+      regval &= ~pin;
+      putreg32(regval, base + LM3S_GPIO_IM_OFFSET);
+      irqrestore(flags);
+      ret = OK;
+    }
+  return ret;
+}
+
diff --git a/nuttx/arch/arm/src/lm3s/lm3s_internal.h b/nuttx/arch/arm/src/lm3s/lm3s_internal.h
index 0f48c6f23..22a69a24c 100644
--- a/nuttx/arch/arm/src/lm3s/lm3s_internal.h
+++ b/nuttx/arch/arm/src/lm3s/lm3s_internal.h
@@ -250,8 +250,6 @@ EXTERN void lm3s_clockconfig(uint32 newrcc, uint32 newrcc2);
 
 EXTERN void up_clockconfig(void);
 
-/* Configure a GPIO pin */
-
 /****************************************************************************
  * Name: lm3s_configgpio
  *
@@ -292,6 +290,16 @@ EXTERN void lm3s_gpiowrite(uint32 pinset, boolean value);
 
 EXTERN boolean lm3s_gpioread(uint32 pinset, boolean value);
 
+/****************************************************************************
+ * Name: gpio_irqinitialize
+ *
+ * Description:
+ *   Initialize all vectors to the unexpected interrupt handler
+ *
+ ****************************************************************************/
+
+EXTERN int weak_function gpio_irqinitialize(void);
+
 #undef EXTERN
 #if defined(__cplusplus)
 }
diff --git a/nuttx/arch/arm/src/lm3s/lm3s_irq.c b/nuttx/arch/arm/src/lm3s/lm3s_irq.c
index 80bb33503..def4ce391 100644
--- a/nuttx/arch/arm/src/lm3s/lm3s_irq.c
+++ b/nuttx/arch/arm/src/lm3s/lm3s_irq.c
@@ -175,6 +175,17 @@ void up_irqinitialize(void)
 
   current_regs = NULL;
 
+  /* Initialize support for GPIO interrupts if included in this build */
+
+#ifndef CONFIG_LM3S_DISABLE_GPIO_IRQS
+#ifdef CONFIG_HAVE_WEAKFUNCTIONS
+  if (gpio_irqinitialize != NULL)
+#endif
+    {
+      gpio_irqinitialize();
+    }
+#endif
+
   /* Attach the PendSV exception handler and set it to the minimum
    * prioirity.  The PendSV exception is used for performing
    * context switches.