add dma

Author: andete

.gitignore

@@ -0,0 +1 @@
+*~

tool/dma.h

@@ -0,0 +1,19 @@
+/* -*- Mode: C; tab-width: 2; indent-tabs-mode: nil -*- */
+
+/* DMA control block, must be aligned to 256. */
+DMA_DESCRIPTOR_TypeDef dma_control_block[DMA_CHAN_COUNT * 2] __attribute__ ((aligned(256)));
+
+namespace dma {
+
+  DMA_Init_TypeDef dmaInit = {
+    .hprot        = 0,                 // No descriptor protection
+    .controlBlock = dma_control_block, // DMA control block alligned to 256
+  };
+
+  static void setup() {
+
+    DMA_Init(&dmaInit);
+
+  }
+
+}

tool/leuart0.h

@@ -1,23 +1,58 @@
 /* -*- Mode: C; tab-width: 2; indent-tabs-mode: nil -*- */
 
+#define LEUART0_DMA_CHANNEL    0
+#define LEUART0_BUF_MAX        255
+
 namespace leuart0 {
 
   // extra serial interface for debugging
 
   // PD4: TX
   // PD5: RX
 
+  static char rxbuf[LEUART0_BUF_MAX] = {0};
+
+  LEUART_Init_TypeDef init = {
+    .enable   = leuartEnableRx, // Activate data reception on LEUn_RX pin.
+    .refFreq  = 0, // Inherit the clock frequenzy from the LEUART clock source
+    .baudrate = 9600,
+    .databits = leuartDatabits8,
+    .parity   = leuartNoParity,
+    .stopbits = leuartStopbits1,
+  }; 
+
+  DMA_Init_TypeDef dma_init = {
+    .hprot        = 0,                  // No descriptor protection
+    .controlBlock = dmaControlBlock,    // DMA control block alligned to 256
+  };
+
+  DMA_CfgChannel_TypeDef chnlCfg = {
+    .highPri   = false, // Normal priority
+    .enableInt = false, // No interupt enabled for callback functions
+    // Set LEUART0 RX data available as source of DMA signals:
+    .select    = DMAREQ_LEUART0_RXDATAV,
+    .cb        = NULL,
+  };
+
+  DMA_CfgDescr_TypeDef descrCfg = {
+    .dstInc  = dmaDataInc1,    // Increment destination address by one byte
+    .srcInc  = dmaDataIncNone, // Do no increment source address
+    .size    = dmaDataSize1,   // Data size is one byte
+    .arbRate = dmaArbitrate1,  // Rearbitrate for each byte recieved
+    .hprot   = 0,              // No read/write source protection
+  };
+
+
   static void setup() {
+    GPIO_PinModeSet(gpioPortD, 4, gpioModePushPull, 1);
+    GPIO_PinModeSet(gpioPortD, 5, gpioModeInput, 0);
     // To avoid false start, configure output LEU0_TX as high on PD4
-    GPIO->P[3].DOUT |= (1 << 4);
-    // Pin PD4 is configured to Push-pull
-    GPIO->P[3].MODEL = (GPIO->P[3].MODEL & ~_GPIO_P_MODEL_MODE4_MASK) | GPIO_P_MODEL_MODE4_PUSHPULL;
-    // Pin PD5 is configured to Input enabled
-    GPIO->P[3].MODEL = (GPIO->P[3].MODEL & ~_GPIO_P_MODEL_MODE5_MASK) | GPIO_P_MODEL_MODE5_INPUT;
+    GPIO_PinOutSet(gpioPortD, 4);
 
 
-    // Enable signals TX, RX
-    LEUART0->ROUTE |= LEUART_ROUTE_TXPEN | LEUART_ROUTE_RXPEN;
+    // Enable signals TX, RX at location 0
+    LEUART0->ROUTE |= LEUART_ROUTE_TXPEN | LEUART_ROUTE_RXPEN 
+        | LEUART_ROUTE_LOCATION_LOC0;
   }
 
 }

tool/main.cc

@@ -6,8 +6,12 @@
 #include "em_adc.h"
 #include "em_cmu.h"
 #include "em_usart.h"
+#include "em_leuart.h"
+#include "em_dma.h"
+#include "em_gpio.h"
 
 // own code
+#include "dma.h"
 #include "tick.h"
 #include "clock.h"
 #include "adc0.h"
@@ -23,6 +27,7 @@ static void setup() {
 
   tick::setup();
   clock::setup();
+  dma::setup();
   adc0::setup();
   leuart0::setup();
   timer0::setup();

tool/swd.h

@@ -0,0 +1,12 @@
+/* -*- Mode: C; tab-width: 2; indent-tabs-mode: nil -*- */
+
+namespace swd {
+
+  static void setup() {
+
+    // enable SWO tracing output
+    GPIO->ROUTE |= GPIO_ROUTE_SWOPEN;
+
+  }
+
+}