Diff: Drivers/dma.c

Revision:

0:e57bc370d339

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Drivers/dma.c	Tue Jan 05 11:45:44 2016 +0000
@@ -0,0 +1,63 @@
+/*
+ * dma.c
+ *
+ *  Created on: 03/07/2011
+ *      Author: francisco
+ */
+#include <LPC17xx.h>
+#include "dma.h"
+
+#define LPC_GPDMACH          ((LPC_GPDMACH_TypeDef   **) LPC_GPDMACH0_BASE )
+
+void init_dma()
+{
+    LPC_SC->PCONP |= 1<<29;     //Power GPDMA module
+
+    LPC_GPDMA->DMACConfig = 1;  //Enable GPDMA
+
+    //Clear any previous interrupts
+    LPC_GPDMA->DMACIntTCClear = 0xFF;
+    LPC_GPDMA->DMACIntErrClr = 0xFF;
+
+    NVIC_SetPriority(DMA_IRQn,(1<<__NVIC_PRIO_BITS) - 1);
+    NVIC_EnableIRQ(DMA_IRQn);
+}
+
+void setup_channel(dmaLinkedListNode* pList,int ch,int src,int dst)
+{
+    //Initialize the channel with previously configured LL;
+    LPC_GPDMACH0->DMACCSrcAddr = pList->sourceAddr;
+    LPC_GPDMACH0->DMACCDestAddr = pList->destAddr;
+    LPC_GPDMACH0->DMACCControl = pList->dmaControl;
+    LPC_GPDMACH0->DMACCLLI = (unsigned long int) pList & 0xFFFFFFFC; //Lower bits must be 0
+
+    int transfer_type;
+    if(src == DMA_MEMORY && dst != DMA_MEMORY)
+    {
+        transfer_type = DMA_MEMORY_TO_PERIPHERAL;
+        src = 0;
+    }
+    else if(src != DMA_MEMORY && dst == DMA_MEMORY)
+    {
+        transfer_type = DMA_PERIPHERAL_TO_MEMORY;
+        dst = 0;
+    }
+    else if(src == DMA_MEMORY && dst == DMA_MEMORY)
+    {
+        transfer_type = DMA_MEMORY_TO_MEMORY;
+        src=dst = 0;
+    }
+    else if(src != DMA_MEMORY && dst != DMA_MEMORY)
+        transfer_type = DMA_PERIPHERAL_TO_PERIPHERAL;
+
+    //Set up all relevant bits
+    LPC_GPDMACH0->DMACCConfig = (src<<1) | (dst<<5) | (transfer_type<<11) | (1<<15);
+
+    //Finally, enable the channel -
+    LPC_GPDMACH0->DMACCConfig |= 1<<0;
+}
+
+void stop_channel()
+{
+    LPC_GPDMACH0->DMACCConfig &= ~(1<<0);
+}