From e4574fa3bfb1a80218292b5f3b76778bf76cae84 Mon Sep 17 00:00:00 2001
From: Kamil Tomaszewski <kamil.tomaszewski@sony.com>
Date: Mon, 21 Oct 2019 13:17:51 +0200
Subject: [PATCH] Clean UART on reset

---
 ports/cxd56/common-hal/busio/UART.c | 9 +++++++++
 ports/cxd56/common-hal/busio/UART.h | 2 ++
 ports/cxd56/supervisor/port.c       | 4 ++++
 3 files changed, 15 insertions(+)

diff --git a/ports/cxd56/common-hal/busio/UART.c b/ports/cxd56/common-hal/busio/UART.c
index 6c59c8f283..4a1376f19a 100644
--- a/ports/cxd56/common-hal/busio/UART.c
+++ b/ports/cxd56/common-hal/busio/UART.c
@@ -187,3 +187,12 @@ bool common_hal_busio_uart_ready_to_tx(busio_uart_obj_t *self) {
     ioctl(busio_uart_dev[self->number].fd, TCFLSH, (long unsigned int)NULL);
     return true;
 }
+
+void busio_uart_reset(void) {
+    for (int i = 0; i < MP_ARRAY_SIZE(busio_uart_dev); i++) {
+        if (busio_uart_dev[i].fd >= 0) {
+            close(busio_uart_dev[i].fd);
+            busio_uart_dev[i].fd = -1;
+        }
+    }
+}
diff --git a/ports/cxd56/common-hal/busio/UART.h b/ports/cxd56/common-hal/busio/UART.h
index c1f6fff533..e1d8161491 100644
--- a/ports/cxd56/common-hal/busio/UART.h
+++ b/ports/cxd56/common-hal/busio/UART.h
@@ -40,4 +40,6 @@ typedef struct {
     uint32_t timeout;
 } busio_uart_obj_t;
 
+void busio_uart_reset(void);
+
 #endif // MICROPY_INCLUDED_CXD56_COMMON_HAL_BUSIO_UART_H
diff --git a/ports/cxd56/supervisor/port.c b/ports/cxd56/supervisor/port.c
index 3fddfe52c6..c7ed4b232e 100644
--- a/ports/cxd56/supervisor/port.c
+++ b/ports/cxd56/supervisor/port.c
@@ -35,6 +35,7 @@
 #include "common-hal/analogio/AnalogIn.h"
 #include "common-hal/pulseio/PulseOut.h"
 #include "common-hal/pulseio/PWMOut.h"
+#include "common-hal/busio/UART.h"
 
 safe_mode_t port_init(void) {
     boardctl(BOARDIOC_INIT, 0);
@@ -60,6 +61,9 @@ void reset_port(void) {
     pulseout_reset();
     pwmout_reset();
 #endif
+#if CIRCUITPY_BUSIO
+    busio_uart_reset();
+#endif
 
     reset_all_pins();
 }