Cortex-A9 GIC: Add an interface to set interrupt edge/level trigger

arch/arm/src/armv7-a/arm_gicv2.c

@@ -523,4 +523,56 @@ int up_prioritize_irq(int irq, int priority)
   return -EINVAL;
 }
 
+/****************************************************************************
+ * Name: arm_gic_irq_trigger
+ *
+ * Description:
+ *   Set the trigger type for the specificd IRQ source and the current CPU.
+ *
+ *   Since this API is not supported on all architectures, it should be
+ *   avoided in common implementations where possible.
+ *
+ * Input Paramters:
+ *   irq - The interrupt request to modify.
+ *   edge - False: Active HIGH level sensitive, True: Rising edge sensitive
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value is returned on any failure.
+ *
+ ****************************************************************************/
+
+int arm_gic_irq_trigger(int irq, bool edge)
+{
+  uintptr_t regaddr;
+  uint32_t regval;
+  uint32_t intcfg;
+
+  if (irq > GIC_IRQ_SGI15 && irq < NR_IRQS)
+    {
+      /* Get the address of the Interrupt Configuration Register for this
+       * irq.
+       */
+
+      regaddr = GIC_ICDICFR(irq);
+
+      /* Get the new Interrupt configuration bit setting */
+
+      intcfg = (edge ? (INT_ICDICFR_EDGE | INT_ICDICFR_1N) : INT_ICDICFR_1N);
+
+      /* Write the correct interrupt trigger to the Interrupt Configuration
+       * Register.
+       */
+
+      regval  = getreg32(regaddr);
+      regval &= ~GIC_ICDICFR_ID_MASK(irq);
+      regval |= GIC_ICDICFR_ID(irq, intcfg);
+      putreg32(regval, regaddr);
+
+      return OK;
+    }
+
+  return -EINVAL;
+}
+
+
 #endif /* CONFIG_ARMV7A_HAVE_GICv2 */

arch/arm/src/armv7-a/gic.h

@@ -495,7 +495,7 @@
 #define INT_ICDICFR_EDGE           2         /* Bit n+2: 1=Edge sensitive */
 
 #define GIC_ICDICFR_ID_SHIFT(n)    GIC_SHIFT16(n)
-#define GIC_ICDICFR_ID_MASK(n)     GIC_MASK16(n
+#define GIC_ICDICFR_ID_MASK(n)     GIC_MASK16(n)
 #  define GIC_ICDICFR_ID(n,c)      ((uint32_t)(c) << GIC_SHIFT16(n))
 
 /* PPI Status Register */
@@ -720,6 +720,26 @@ void arm_gic0_initialize(void);
 
 void arm_gic_initialize(void);
 
+/****************************************************************************
+ * Name: arm_gic_irq_trigger
+ *
+ * Description:
+ *   Set the trigger type for the specificd IRQ source and the current CPU.
+ *
+ *   Since this API is not supported on all architectures, it should be
+ *   avoided in common implementations where possible.
+ *
+ * Input Paramters:
+ *   irq - The interrupt request to modify.
+ *   edge - False: Active HIGH level sensitive, True: Rising edge sensitive
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value is returned on any failure.
+ *
+ ****************************************************************************/
+
+int arm_gic_irq_trigger(int irq, bool edge);
+
 /****************************************************************************
  * Name: arm_decodeirq
  *

arch/arm/src/imx6/imx_serial.c

@@ -57,6 +57,7 @@
 #include "up_arch.h"
 #include "up_internal.h"
 
+#include "gic.h"
 #include "chip/imx_uart.h"
 #include "imx_config.h"
 #include "imx_lowputc.h"
@@ -613,6 +614,10 @@ static int imx_attach(struct uart_dev_s *dev)
   ret = irq_attach(priv->irq, priv->handler);
   if (ret == OK)
     {
+      /* Configure as a (high) level interrupt */
+
+      (void)arm_gic_irq_trigger(priv->irq, false);
+
       /* Enable the interrupt (RX and TX interrupts are still disabled
        * in the UART
        */

arch/arm/src/imx6/imx_timerisr.c

@@ -46,6 +46,7 @@
 #include <arch/irq.h>
 
 #include "up_arch.h"
+#include "gic.h"
 #include "chip/imx_ccm.h"
 #include "chip/imx_gpt.h"
 
@@ -235,6 +236,10 @@ void up_timer_initialize(void)
   cr |= GPT_CR_EN;
   putreg32(cr, IMX_GPT_CR);
 
+  /* Configure as a (rising) edge-triggered interrupt */
+
+  (void)arm_gic_irq_trigger(IMX_IRQ_GPT, true);
+
   /* Attach the timer interrupt vector */
 
   (void)irq_attach(IMX_IRQ_GPT, (xcpt_t)up_timerisr);

configs/sabre-6quad/README.txt

@@ -46,6 +46,14 @@ no interrupt driver serial console output (syslog, printf).
 
 2016-05-16:  I know get serial interrupts (but not timer interrupts).  This
 involves a few changes to GIC bit settings that I do not fully understand.
+With this change, the NSH serial console works:
+
+  MX6Q SABRESD U-Boot > ABEFGHILMN
+
+  NuttShell (NSH)
+  nsh>
+
+But there are still no timer interrupts.
 
 Platform Features
 =================