XMC47: eLua serial console: Enable DMA mode for UART0

src/platform/xmc4000/platform.c

@@ -178,14 +178,28 @@ timer_data_type platform_s_timer_op( unsigned id, int op,timer_data_type data )
 // ****************************************************************************
 // UART
 
+void elua_uart_rx_callback( void )
+{
+  // Empty for now.
+}
+
+void elua_uart_tx_callback( void )
+{
+  // Empty for now.
+}
+
 void platform_s_uart_send( unsigned id, u8 data )
 {
+  // Internally invokes DMA for transmit
   UART_Transmit( &UART_0, &data, 1 );
+  while( UART_0.runtime->tx_busy );
 }
 
 int platform_s_uart_recv( unsigned id, timer_data_type timeout )
 {
+  // Internally invokes DMA for receive
   UART_Receive( &UART_0, &recv_byte, 1 );
+  while( UART_0.runtime->rx_busy );
   return recv_byte;
 }
 

src/platform/xmc4000/xmclib/gen/UART/uart_conf.c

@@ -75,6 +75,8 @@ extern void UART_lProtocolHandler(const UART_t * const handle);
  * DATA STRUCTURES
  **********************************************************************************************************************/
 UART_STATUS_t UART_0_init(void);
+void UART_0_dma_tx_handler(XMC_DMA_CH_EVENT_t event);
+void UART_0_dma_rx_handler(XMC_DMA_CH_EVENT_t event);
 
 /*USIC channel configuration*/
 const XMC_UART_CH_CONFIG_t UART_0_channel_config =
@@ -102,12 +104,56 @@ const UART_TX_CONFIG_t UART_0_tx_pin =
   .pin = 5U
 };
 
+const XMC_DMA_CH_CONFIG_t UART_0_tx_dma_ch_config =
+{
+  .enable_interrupt = true,
+  .dst_transfer_width = (uint32_t)XMC_DMA_CH_TRANSFER_WIDTH_8,
+  .src_transfer_width = (uint32_t)XMC_DMA_CH_TRANSFER_WIDTH_8,
+  .dst_address_count_mode = (uint32_t)XMC_DMA_CH_ADDRESS_COUNT_MODE_NO_CHANGE,
+  .src_address_count_mode = (uint32_t)XMC_DMA_CH_ADDRESS_COUNT_MODE_INCREMENT,
+  .dst_burst_length = (uint32_t)XMC_DMA_CH_BURST_LENGTH_1,
+  .src_burst_length = (uint32_t)XMC_DMA_CH_BURST_LENGTH_8,
+  .transfer_flow = (uint32_t)XMC_DMA_CH_TRANSFER_FLOW_M2P_DMA,
+  .transfer_type = (uint32_t)XMC_DMA_CH_TRANSFER_TYPE_SINGLE_BLOCK,
+  .dst_handshaking = (uint32_t)XMC_DMA_CH_DST_HANDSHAKING_HARDWARE,
+  .dst_peripheral_request = DMA_PERIPHERAL_REQUEST(5U, 10U), /*DMA0_PERIPHERAL_REQUEST_USIC0_SR0_5*/
+};
+
+const UART_DMA_CONFIG_t UART_0_tx_dma_config =
+{
+  .dma_ch_config = &UART_0_tx_dma_ch_config,
+  .dma_channel   = 5U
+};
+
+const XMC_DMA_CH_CONFIG_t UART_0_rx_dma_ch_config =
+{
+  .enable_interrupt = true,
+  .dst_transfer_width = (uint32_t)XMC_DMA_CH_TRANSFER_WIDTH_8,
+  .src_transfer_width = (uint32_t)XMC_DMA_CH_TRANSFER_WIDTH_8,
+  .dst_address_count_mode = (uint32_t)XMC_DMA_CH_ADDRESS_COUNT_MODE_INCREMENT,
+  .src_address_count_mode = (uint32_t)XMC_DMA_CH_ADDRESS_COUNT_MODE_NO_CHANGE,
+  .dst_burst_length = (uint32_t)XMC_DMA_CH_BURST_LENGTH_8,
+  .src_burst_length = (uint32_t)XMC_DMA_CH_BURST_LENGTH_1,
+  .transfer_flow = (uint32_t)XMC_DMA_CH_TRANSFER_FLOW_P2M_DMA,
+  .transfer_type = (uint32_t)XMC_DMA_CH_TRANSFER_TYPE_SINGLE_BLOCK,
+  .src_handshaking = (uint32_t)XMC_DMA_CH_SRC_HANDSHAKING_HARDWARE,
+  .src_peripheral_request = DMA_PERIPHERAL_REQUEST(2U, 11U), /*DMA0_PERIPHERAL_REQUEST_USIC0_SR1_2*/
+};
+
+const UART_DMA_CONFIG_t UART_0_rx_dma_config =
+{
+  .dma_ch_config = &UART_0_rx_dma_ch_config,
+  .dma_channel   = 4U
+};
+
 /*UART APP configuration structure*/
 const UART_CONFIG_t UART_0_config = 
 {
   .channel_config   = &UART_0_channel_config,
 
-
+  .global_dma    = &GLOBAL_DMA_0,
+  .transmit_dma_config = &UART_0_tx_dma_config,
+  .receive_dma_config = &UART_0_rx_dma_config,
   .fptr_uart_config = UART_0_init,  
   .sync_error_cbhandler = NULL,  
   .rx_noise_error_cbhandler = NULL,  
@@ -116,10 +162,10 @@ const UART_CONFIG_t UART_0_config =
   .collision_error_cbhandler = NULL,
   .tx_pin_config    = &UART_0_tx_pin,
   .mode             = UART_MODE_FULLDUPLEX,
-  .transmit_mode = UART_TRANSFER_MODE_DIRECT,
+  .transmit_mode = UART_TRANSFER_MODE_DMA,
-  .receive_mode = UART_TRANSFER_MODE_DIRECT,
+  .receive_mode = UART_TRANSFER_MODE_DMA,
-  .tx_fifo_size     = XMC_USIC_CH_FIFO_SIZE_16WORDS,
+  .tx_fifo_size     = XMC_USIC_CH_FIFO_DISABLED,
-  .rx_fifo_size     = XMC_USIC_CH_FIFO_SIZE_16WORDS,
+  .rx_fifo_size     = XMC_USIC_CH_FIFO_DISABLED,
 };
 
 /*Runtime handler*/
@@ -150,32 +196,65 @@ const XMC_GPIO_CONFIG_t UART_0_rx_pin_config   = {
 UART_STATUS_t UART_0_init()
 {
   UART_STATUS_t status = UART_STATUS_SUCCESS;
+  status = (UART_STATUS_t)GLOBAL_DMA_Init(&GLOBAL_DMA_0);
+  XMC_DMA_CH_Init(XMC_DMA0, 5U, &UART_0_tx_dma_ch_config);
+  XMC_DMA_CH_EnableEvent(XMC_DMA0,  5U, XMC_DMA_CH_EVENT_TRANSFER_COMPLETE);
+
+  XMC_DMA_CH_Init(XMC_DMA0, 4U, &UART_0_rx_dma_ch_config);
+  XMC_DMA_CH_EnableEvent(XMC_DMA0,  4U, XMC_DMA_CH_EVENT_TRANSFER_COMPLETE);
+
   /*Configure Receive pin*/
   XMC_GPIO_Init((XMC_GPIO_PORT_t *)PORT1_BASE, 4U, &UART_0_rx_pin_config);
   /* Initialize USIC channel in UART mode*/
   XMC_UART_CH_Init(XMC_UART0_CH0, &UART_0_channel_config);
   /*Set input source path*/
   XMC_USIC_CH_SetInputSource(XMC_UART0_CH0, XMC_USIC_CH_INPUT_DX0, 1U);
-  /*Configure transmit FIFO*/
-  XMC_USIC_CH_TXFIFO_Configure(XMC_UART0_CH0,
-        16U,
-        XMC_USIC_CH_FIFO_SIZE_16WORDS,
-        1U);
-  /*Configure receive FIFO*/
-  XMC_USIC_CH_RXFIFO_Configure(XMC_UART0_CH0,
-        0U,
-        XMC_USIC_CH_FIFO_SIZE_16WORDS,
-        15U);
   /* Start UART */
   XMC_UART_CH_Start(XMC_UART0_CH0);
 
   /* Initialize UART TX pin */
   XMC_GPIO_Init((XMC_GPIO_PORT_t *)PORT1_BASE, 5U, &UART_0_tx_pin_config);
 
+  /*Set service request for transmit interrupt*/
+  XMC_USIC_CH_SetInterruptNodePointer(XMC_UART0_CH0, XMC_USIC_CH_INTERRUPT_NODE_POINTER_TRANSMIT_BUFFER,
+     0U);
+  /*Set service request for receive interrupt*/
+  XMC_USIC_CH_SetInterruptNodePointer(XMC_UART0_CH0, XMC_USIC_CH_INTERRUPT_NODE_POINTER_RECEIVE,
+     1U);
+  XMC_USIC_CH_SetInterruptNodePointer(XMC_UART0_CH0, XMC_USIC_CH_INTERRUPT_NODE_POINTER_ALTERNATE_RECEIVE,
+     1U);
   /*Set service request for UART protocol events*/
   XMC_USIC_CH_SetInterruptNodePointer(XMC_UART0_CH0, XMC_USIC_CH_INTERRUPT_NODE_POINTER_PROTOCOL,
-     0U);
+     2U);
+  /*Register transfer complete event handler*/
+  XMC_DMA_CH_SetEventHandler(XMC_DMA0, 4U, UART_0_dma_rx_handler);
+  /*Register transfer complete event handler*/
+  XMC_DMA_CH_SetEventHandler(XMC_DMA0, 5U, UART_0_dma_tx_handler);
+  /* make DMA ready for transmission*/
+  XMC_USIC_CH_TriggerServiceRequest(XMC_UART0_CH0, 0U); 
   return status;
 }
+
+void UART_0_dma_tx_handler(XMC_DMA_CH_EVENT_t event)
+{
+  if(event == XMC_DMA_CH_EVENT_TRANSFER_COMPLETE)
+  {
+    UART_0.runtime->tx_busy = false;
+    elua_uart_tx_callback();
+
+  }
+}
+
+
+void UART_0_dma_rx_handler(XMC_DMA_CH_EVENT_t event)
+{
+  if(event == XMC_DMA_CH_EVENT_TRANSFER_COMPLETE)
+  {
+    UART_0.runtime->rx_busy = false;
+    elua_uart_rx_callback();
+
+  }
+}
+
 /*CODE_BLOCK_END*/
 

src/platform/xmc4000/xmclib/gen/UART/uart_conf.h

@@ -61,8 +61,8 @@
 #define UART_PATCH_VERSION (10U)
 
 
-#define UART_TX_DIRECT_USED
+#define UART_TX_DMA_USED
-#define UART_RX_DIRECT_USED
+#define UART_RX_DMA_USED
 
 #endif /* End of UART_CONF_H */
 /*CODE_BLOCK_END*/

src/platform/xmc4000/xmclib/gen/UART/uart_extern.h

@@ -65,6 +65,8 @@ extern "C" {
 #endif
   
 /*Extern declaration for callback functions and UART APP instance handles*/
+  extern void elua_uart_tx_callback(void);
+  extern void elua_uart_rx_callback(void);
 
   extern UART_t UART_0;