1 files changed, 100 insertions, 0 deletions
diff --git a/app/usart.c b/app/usart.c
new file mode 100644
index 0000000..74e5383
--- /dev/null
+++ b/app/usart.c
@@ -0,0 +1,100 @@
+#include "project.h"
+
+#define BUFFER_SIZE 256
+
+
+#define USART1_TX GPIO_USART1_TX
+#define USART1_TX_PORT GPIOA
+
+#define USART1_RX GPIO_USART1_RX
+#define USART1_RX_PORT GPIOA
+
+
+
+ring_t rx1_ring;
+static uint8_t rx1_ring_buf[BUFFER_SIZE];
+
+ring_t tx1_ring;
+static uint8_t tx1_ring_buf[BUFFER_SIZE];
+
+void
+usart1_isr (void)
+{
+  uint8_t data;
+
+  /* Check if we were called because of RXNE. */
+  if (((USART_CR1 (USART1) & USART_CR1_RXNEIE) != 0) &&
+      ((USART_SR (USART1) & USART_SR_RXNE) != 0))
+    {
+      data = usart_recv (USART1);
+      ring_write_byte(&rx1_ring,data);
+    }
+
+  /* Check if we were called because of TXE. */
+  if (((USART_CR1 (USART1) & USART_CR1_TXEIE) != 0) &&
+      ((USART_SR (USART1) & USART_SR_TXE) != 0))
+    {
+
+      if (ring_read_byte (&tx1_ring, &data))
+        {
+	  /*No more data, Disable the TXE interrupt, it's no longer needed. */
+	  usart_disable_tx_interrupt(USART1);
+        }
+      else
+        {
+          usart_send_blocking (USART1, data);
+        }
+    }
+
+}
+
+
+void
+usart1_queue (uint8_t d)
+{
+  ring_write_byte (&tx1_ring, d);
+  usart_enable_tx_interrupt(USART1);
+}
+
+void
+usart1_drain (void)
+{
+  while (!ring_empty (&tx1_ring));
+}
+
+
+int
+usart1_write (char *ptr, int len,int blocking)
+{
+  int ret;
+
+      ret = ring_write (&tx1_ring, (uint8_t *) ptr, len,blocking);
+      usart_enable_tx_interrupt(USART1);
+      return ret;
+}
+
+
+void
+usart_init (void)
+{
+  ring_init (&rx1_ring, rx1_ring_buf, sizeof (rx1_ring_buf));
+  ring_init (&tx1_ring, tx1_ring_buf, sizeof (tx1_ring_buf));
+
+  nvic_enable_irq (NVIC_USART1_IRQ);
+
+
+  MAP_AF(USART1_TX);
+  MAP_AF_PU(USART1_RX);
+
+
+  usart_set_baudrate (USART1, 38400);
+  usart_set_databits (USART1, 8);
+  usart_set_stopbits (USART1, USART_STOPBITS_1);
+  usart_set_parity (USART1, USART_PARITY_NONE);
+  usart_set_flow_control (USART1, USART_FLOWCONTROL_NONE);
+  usart_set_mode (USART1, USART_MODE_TX_RX);
+
+  USART_CR1 (USART1) |= USART_CR1_RXNEIE;
+
+  usart_enable (USART1);
+}