[PATCH] Added interrupt handler for DMA channel 0, 1 & 2

[Mudit Jain]

Added macros for DMA channels 0-12
Added interrupt handlers for DMA 0, 1 & 2

The added IRQs are in accordance with the
BCM Peripherals Datasheet and also have been verified
with the linux source code for RPi
---
 c/src/lib/libbsp/arm/raspberrypi/include/irq.h | 17 ++++++++++
 c/src/lib/libbsp/arm/raspberrypi/irq/irq.c     | 45 ++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

diff --git a/c/src/lib/libbsp/arm/raspberrypi/include/irq.h b/c/src/lib/libbsp/arm/raspberrypi/include/irq.h
index 8436c2d..50616e1 100644
--- a/c/src/lib/libbsp/arm/raspberrypi/include/irq.h
+++ b/c/src/lib/libbsp/arm/raspberrypi/include/irq.h
@@ -35,6 +35,23 @@
 
 #define BCM2835_INTC_TOTAL_IRQ       64 + 8
 
+/* DMA Interrupt is routed to IRQ 16 for DMA Channel 0,
+   IRQ 17 for Channel 1, and so on till IRQ 28 for Channel 12.
+ */
+
+#define BCM2835_IRQ_ID_DMA_CH0       16
+#define BCM2835_IRQ_ID_DMA_CH1       17
+#define BCM2835_IRQ_ID_DMA_CH2       18
+#define BCM2835_IRQ_ID_DMA_CH3       19
+#define BCM2835_IRQ_ID_DMA_CH4       20
+#define BCM2835_IRQ_ID_DMA_CH5       21
+#define BCM2835_IRQ_ID_DMA_CH6       22
+#define BCM2835_IRQ_ID_DMA_CH7       23
+#define BCM2835_IRQ_ID_DMA_CH8       24
+#define BCM2835_IRQ_ID_DMA_CH9       25
+#define BCM2835_IRQ_ID_DMA_CH10      26
+#define BCM2835_IRQ_ID_DMA_CH11      27
+#define BCM2835_IRQ_ID_DMA_CH12      28
 
 #define BCM2835_IRQ_ID_AUX           29
 #define BCM2835_IRQ_ID_SPI_SLAVE     43
diff --git a/c/src/lib/libbsp/arm/raspberrypi/irq/irq.c b/c/src/lib/libbsp/arm/raspberrypi/irq/irq.c
index 7b3b2be..3279b35 100644
--- a/c/src/lib/libbsp/arm/raspberrypi/irq/irq.c
+++ b/c/src/lib/libbsp/arm/raspberrypi/irq/irq.c
@@ -64,6 +64,21 @@ void bsp_interrupt_dispatch(void)
   {
       vector = BCM2835_IRQ_ID_UART;
   }
+  /* DMA 0 */
+  else if ( BCM2835_REG(BCM2835_IRQ_PENDING1) & BCM2835_BIT(16) )
+  {
+      vector = BCM2835_IRQ_ID_DMA_CH0;
+  }
+  /* DMA 1 */
+  else if ( BCM2835_REG(BCM2835_IRQ_PENDING1) & BCM2835_BIT(17) )
+  {
+      vector = BCM2835_IRQ_ID_DMA_CH1;
+  }
+  /* DMA 2 */
+  else if ( BCM2835_REG(BCM2835_IRQ_PENDING1) & BCM2835_BIT(18) )
+  {
+      vector = BCM2835_IRQ_ID_DMA_CH2;
+  }
   /* GPIO 0*/
   else if ( BCM2835_REG(BCM2835_IRQ_PENDING2) & BCM2835_BIT(17) )
   {
@@ -114,6 +129,21 @@ rtems_status_code bsp_interrupt_vector_enable(rtems_vector_number vector)
   {
       BCM2835_REG(BCM2835_IRQ_ENABLE2) =  BCM2835_BIT(25);
   }
+  /* DMA 0 */
+  else if ( vector == BCM2835_IRQ_ID_DMA_CH0 )
+  {
+      BCM2835_REG(BCM2835_IRQ_ENABLE1) =  BCM2835_BIT(16);
+  }
+  /* DMA 1 */
+  else if ( vector == BCM2835_IRQ_ID_DMA_CH1 )
+  {
+      BCM2835_REG(BCM2835_IRQ_ENABLE1) =  BCM2835_BIT(17);
+  }
+  /* DMA 2 */
+  else if ( vector == BCM2835_IRQ_ID_DMA_CH2 )
+  {
+      BCM2835_REG(BCM2835_IRQ_ENABLE1) =  BCM2835_BIT(18);
+  }
   /* GPIO 0 */
   else if ( vector == BCM2835_IRQ_ID_GPIO_0 )
   {
@@ -164,6 +194,21 @@ rtems_status_code bsp_interrupt_vector_disable(rtems_vector_number vector)
   {
       BCM2835_REG(BCM2835_IRQ_DISABLE2) = BCM2835_BIT(25);
   }
+  /* DMA 0 */
+  else if ( vector == BCM2835_IRQ_ID_DMA_CH0 )
+  {
+      BCM2835_REG(BCM2835_IRQ_DISABLE1) = BCM2835_BIT(16);
+  }
+  /* DMA 1 */
+  else if ( vector == BCM2835_IRQ_ID_DMA_CH1 )
+  {
+      BCM2835_REG(BCM2835_IRQ_DISABLE1) = BCM2835_BIT(17);
+  }
+  /* DMA 2 */
+  else if ( vector == BCM2835_IRQ_ID_DMA_CH2 )
+  {
+      BCM2835_REG(BCM2835_IRQ_DISABLE1) = BCM2835_BIT(18);
+  }
   /* GPIO 0 */
   else if ( vector == BCM2835_IRQ_ID_GPIO_0 )
   {
-- 
1.9.1