Diff: dma.cpp

Revision:

0:8e50c5fd42f6

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dma.cpp	Mon Mar 09 21:29:27 2015 +0000
@@ -0,0 +1,82 @@
+#include "dma.h"
+
+namespace mbed {
+
+
+DMA::DMA (int priority):
+channel_num(_channel_num) 
+{
+    chan = chooseFreeChannel(priority) ;
+//    channel_num = _channel_num;
+    DMA_reset(chan);// reset the register value to default and clear the interrupts
+    dma_init_struct = DMA_struct_create(); // initialize the dma data structure to default value
+}
+
+
+DMA::~DMA()
+{
+    DMA_struct_delete(dma_init_struct);
+    DMA_IRQ_detach(chan);
+}
+
+// if no channel choosed, choose whichever free channel, otherwise, wait until the channel is free
+int DMA::chooseFreeChannel (int channel)
+{
+    int reval=channel;
+    if (channel > (channel_num-1) || channel < 0) 
+    {
+        reval = 0;
+        while (1) { //if not chosen channel, round robin checked which channel is free
+            if (!DMA_channel_active(reval))
+                return reval;
+            reval++;
+            if (reval>(channel_num-1))
+                reval=0;
+        }
+    } 
+    else
+    {
+        while (DMA_channel_active(reval));//if has chosen the channel, wait until the channel is free
+    }
+    
+    return reval;
+}
+
+void DMA::TriggerSource(TriggerType trig)
+{
+    DMA_trigger_source(dma_init_struct, trig);
+}
+
+void DMA::TriggerDestination(TriggerType trig)
+{
+    DMA_trigger_destination(dma_init_struct, trig);
+}
+
+/*
+void DMA::next(LLI* list)
+{
+        DMA_next(dma_init_struct, list);
+}
+*/
+
+void DMA::next(const uint32_t src, const uint32_t dst, uint32_t size)
+{
+    DMA_next(dma_init_struct, src, dst, size);
+}
+
+void DMA::start (unsigned int len)
+{
+    DMA_init(chan,dma_init_struct);
+    DMA_start(chan, dma_init_struct, len);
+}
+
+void DMA::wait()
+{
+    while (DMA_channel_active(chan));
+}
+
+bool DMA::finished()
+{
+    return !DMA_channel_active(chan);
+}
+}