slip working with int driven rx

mission/testIp.cpp

@@ -9,8 +9,13 @@
 #include <netif/slipif.h>
 #include <sys/socket.h>
 
+#include <xscugic.h>
 #include <xuartps.h>
 
+#undef XUARTPS_IXR_RXOVR
+#define XUARTPS_IXR_RXOVR 0x00000020U /**< Rx Overrun error interrupt */
+#define XUARTPS_IXR_RTRIG 0x00000001U /**< RX FIFO trigger interrupt. */
+
 extern "C" {
 void slipif_rxbyte_input(struct netif *netif, u8_t c);
 
@@ -18,22 +23,41 @@ void myInitDone(void *arg) { puts("init done"); }
 
 struct netif netif;
 
-void pollUart(void *) {
+extern XScuGic xInterruptController; /* Interrupt controller instance */
+
+/** this is based on XUartPs_InterruptHandler() in xuartps_intr.c*/
+void handleUARTInt(void *) {
+  XUartPs_SendByte(STDOUT_BASEADDRESS, 'I');
+
+  u32 IsrStatus;
+
+  /*
+   * Read the interrupt ID register to determine which
+   * interrupt is active
+   */
+  IsrStatus = XUartPs_ReadReg(STDIN_BASEADDRESS, XUARTPS_IMR_OFFSET);
+
+  IsrStatus &= XUartPs_ReadReg(STDIN_BASEADDRESS, XUARTPS_ISR_OFFSET);
+
+  // Onlx RX intterupts are enabled
+  // We do not care which interrupt actually triggered, just get all bytes
+  // available into the stack
+  u32 RecievedByte;
+  while (XUartPs_IsReceiveData(STDIN_BASEADDRESS)) {
+    RecievedByte = XUartPs_ReadReg(STDIN_BASEADDRESS, XUARTPS_FIFO_OFFSET);
+    slipif_received_byte(&netif, (u8)RecievedByte);
+  }
+
+  /* Clear the interrupt status. */
+  XUartPs_WriteReg(STDIN_BASEADDRESS, XUARTPS_ISR_OFFSET, IsrStatus);
+}
+
+void forwardPackets(void *) {
   while (1) {
-    if (XUartPs_IsReceiveData(STDIN_BASEADDRESS)) {
-      u32 RecievedByte;
-      /* Wait until there is data */
-      while (XUartPs_IsReceiveData(STDIN_BASEADDRESS)) {
-        RecievedByte = XUartPs_ReadReg(STDIN_BASEADDRESS, XUARTPS_FIFO_OFFSET);
-        slipif_rxbyte_input(&netif, (u8)RecievedByte);
-      }
-    }
-    vTaskDelay(pdMS_TO_TICKS(5));
+    slipif_process_rxqueue(&netif);
+    vTaskDelay(pdMS_TO_TICKS(10));
   }
 }
-}
-
-
 
 uint32_t sio_data;
 
@@ -41,6 +65,8 @@ sio_fd_t sio_open(u8_t devnum) { return &sio_data; }
 
 void sio_send(u8_t c, sio_fd_t fd) { XUartPs_SendByte(STDOUT_BASEADDRESS, c); }
 
+} // extern "C"
+
 void testIp() {
 
   tcpip_init(myInitDone, nullptr);
@@ -59,14 +85,38 @@ void testIp() {
 
   vTaskDelay(pdMS_TO_TICKS(2000));
 
-  xTaskCreate(
-      pollUart, /* The function that implements the task. */
-      "uart", /* The text name assigned to the task - for debug only as it is not used by the
-                      kernel. */
-      2048, /* The size of the stack to allocate to the task. */
-      nullptr, /* The parameter passed to the task - not used in this simple case. */
-      1,               /* The priority assigned to the task. */
-      nullptr);
+  /* Install the UART Interrupt handler. */
+  BaseType_t xStatus =
+      XScuGic_Connect(&xInterruptController, XPAR_XUARTPS_1_INTR,
+                      (Xil_ExceptionHandler)handleUARTInt, nullptr);
+  configASSERT(xStatus == XST_SUCCESS);
+  (void)xStatus; /* Remove compiler warning if configASSERT() is not defined. */
+
+  // Set trigger level to 62 of 64 bytes, giving interrupt some time to react
+  XUartPs_WriteReg(STDIN_BASEADDRESS, XUARTPS_RXWM_OFFSET, 62);
+
+  // Setting the rx timeout to n*4 -1 bits
+  XUartPs_WriteReg(STDIN_BASEADDRESS, XUARTPS_RXTOUT_OFFSET, 50);
+
+  // enable UART Interrupts
+  u32 mask = XUARTPS_IXR_RTRIG | XUARTPS_IXR_RXOVR | XUARTPS_IXR_RXFULL | XUARTPS_IXR_TOUT;
+  /* Write the mask to the IER Register */
+  XUartPs_WriteReg(STDIN_BASEADDRESS, XUARTPS_IER_OFFSET, mask);
+  /* Write the inverse of the Mask to the IDR register */
+  XUartPs_WriteReg(STDIN_BASEADDRESS, XUARTPS_IDR_OFFSET, (~mask));
+
+  /* Enable the interrupt for the UART1 in the interrupt controller. */
+  XScuGic_Enable(&xInterruptController, XPAR_XUARTPS_1_INTR);
+
+  // Start task to forwad packets from ISR to IP Task
+  xTaskCreate(forwardPackets, /* The function that implements the task. */
+              "slip forward", /* The text name assigned to the task - for debug
+                              only as it is not used by the kernel. */
+              1024,     /* The size of the stack to allocate to the task. */
+              nullptr, /* The parameter passed to the task - not used in this
+                          simple case. */
+              4,       /* The priority assigned to the task. */
+              nullptr);
 
   puts("socket");