1 files changed, 56 insertions, 0 deletions
diff --git a/src/sam3/serial.c b/src/sam3/serial.c
new file mode 100644
index 00000000..1fe55751
--- /dev/null
+++ b/src/sam3/serial.c
@@ -0,0 +1,56 @@
+// sam3x8e serial port
+//
+// Copyright (C) 2016-2018  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU GPLv3 license.
+
+#include "autoconf.h" // CONFIG_SERIAL_BAUD
+#include "board/serial_irq.h" // serial_rx_data
+#include "internal.h" // gpio_peripheral
+#include "sam3x8e.h" // UART
+#include "sched.h" // DECL_INIT
+
+void
+serial_init(void)
+{
+    gpio_peripheral(GPIO('A', 8), 'A', 1);
+    gpio_peripheral(GPIO('A', 9), 'A', 0);
+
+    // Reset uart
+    PMC->PMC_PCER0 = 1 << ID_UART;
+    UART->UART_PTCR = UART_PTCR_RXTDIS | UART_PTCR_TXTDIS;
+    UART->UART_CR = UART_CR_RSTRX | UART_CR_RSTTX | UART_CR_RXDIS | UART_CR_TXDIS;
+    UART->UART_IDR = 0xFFFFFFFF;
+
+    // Enable uart
+    UART->UART_MR = (US_MR_CHRL_8_BIT | US_MR_NBSTOP_1_BIT | UART_MR_PAR_NO
+                     | UART_MR_CHMODE_NORMAL);
+    UART->UART_BRGR = SystemCoreClock / (16 * CONFIG_SERIAL_BAUD);
+    UART->UART_IER = UART_IER_RXRDY;
+    NVIC_EnableIRQ(UART_IRQn);
+    NVIC_SetPriority(UART_IRQn, 0);
+    UART->UART_CR = UART_CR_RXEN | UART_CR_TXEN;
+}
+DECL_INIT(serial_init);
+
+void __visible
+UART_Handler(void)
+{
+    uint32_t status = UART->UART_SR;
+    if (status & UART_SR_RXRDY)
+        serial_rx_byte(UART->UART_RHR);
+    if (status & UART_SR_TXRDY) {
+        uint8_t data;
+        int ret = serial_get_tx_byte(&data);
+        if (ret)
+            UART->UART_IDR = UART_IDR_TXRDY;
+        else
+            UART->UART_THR = data;
+    }
+}
+
+void
+serial_enable_tx_irq(void)
+{
+    UART->UART_IER = UART_IDR_TXRDY;
+}