serial: c33: add flow control to BLE serial

Author: facchinm

cores/arduino/Serial.cpp

@@ -82,10 +82,11 @@ void UART::WrapperCallback(uart_callback_args_t *p_args) {
 }
 
 
-/* -------------------------------------------------------------------------- */
-UART::UART(int _pin_tx, int _pin_rx) :
+UART::UART(int _pin_tx, int _pin_rx, int _pin_rts, int _pin_cts):
   tx_pin(_pin_tx),
   rx_pin(_pin_rx),
+  rts_pin(_pin_rts),
+  cts_pin(_pin_cts),
   init_ok(false) {
 /* -------------------------------------------------------------------------- */    
   uart_cfg.txi_irq = FSP_INVALID_VECTOR;
@@ -94,9 +95,6 @@ UART::UART(int _pin_tx, int _pin_rx) :
   uart_cfg.eri_irq = FSP_INVALID_VECTOR;
 }
 
-
-
-
 /* -------------------------------------------------------------------------- */
 bool UART::setUpUartIrqs(uart_cfg_t &cfg) {
 /* -------------------------------------------------------------------------- */  
@@ -181,9 +179,14 @@ bool  UART::cfg_pins(int max_index) {
   /* actually configuring PIN function */
   ioport_peripheral_t ioport_tx = USE_SCI_EVEN_CFG(cfg_tx) ? IOPORT_PERIPHERAL_SCI0_2_4_6_8 : IOPORT_PERIPHERAL_SCI1_3_5_7_9;
   ioport_peripheral_t ioport_rx = USE_SCI_EVEN_CFG(cfg_rx) ? IOPORT_PERIPHERAL_SCI0_2_4_6_8 : IOPORT_PERIPHERAL_SCI1_3_5_7_9;
-  
+
   R_IOPORT_PinCfg(&g_ioport_ctrl, g_pin_cfg[tx_pin].pin, (uint32_t) (IOPORT_CFG_PERIPHERAL_PIN | ioport_tx));
   R_IOPORT_PinCfg(&g_ioport_ctrl, g_pin_cfg[rx_pin].pin, (uint32_t) (IOPORT_CFG_PERIPHERAL_PIN | ioport_rx));
+  if (rts_pin != -1 && cts_pin != -1) {
+    // hopefully people using flow control have read the datasheet so let's avoid the double check
+    R_IOPORT_PinCfg(&g_ioport_ctrl, g_pin_cfg[rts_pin].pin, (uint32_t) (IOPORT_CFG_PERIPHERAL_PIN | ioport_rx));
+    R_IOPORT_PinCfg(&g_ioport_ctrl, g_pin_cfg[cts_pin].pin, (uint32_t) (IOPORT_CFG_PERIPHERAL_PIN | ioport_rx));
+  }
 
   return true;
 }
@@ -213,6 +216,9 @@ void UART::begin(unsigned long baudrate, uint16_t config) {
     uart_cfg_extend.p_baud_setting                = &uart_baud;
     uart_cfg_extend.flow_control                  = SCI_UART_FLOW_CONTROL_RTS;
     uart_cfg_extend.flow_control_pin              = (bsp_io_port_pin_t) UINT16_MAX;
+    if (rts_pin != -1 && cts_pin != -1) {
+      uart_cfg_extend.flow_control                  = SCI_UART_FLOW_CONTROL_HARDWARE_CTSRTS;
+    }
     uart_cfg_extend.rs485_setting.enable          = SCI_UART_RS485_DISABLE;
     uart_cfg_extend.rs485_setting.polarity        = SCI_UART_RS485_DE_POLARITY_HIGH;
     uart_cfg_extend.rs485_setting.de_control_pin  = (bsp_io_port_pin_t) UINT16_MAX;

cores/arduino/Serial.h

@@ -52,8 +52,8 @@ class UART : public arduino::HardwareSerial {
   public:
     static UART *g_uarts[MAX_UARTS]; 
     static void WrapperCallback(uart_callback_args_t *p_args);
-    
-    UART(int _pin_tx, int _pin_rx);
+
+    UART(int _pin_tx, int _pin_rx, int pin_rts = -1, int pin_cts = -1);
     void begin(unsigned long);
     void begin(unsigned long, uint16_t config);
     void end();
@@ -70,6 +70,8 @@ class UART : public arduino::HardwareSerial {
   private:          
     int                       tx_pin;
     int                       rx_pin;
+    int                       rts_pin = -1;
+    int                       cts_pin = -1;
     bool                      cfg_pins(int max_index);
 
     int                       channel;

cores/arduino/SerialObj3.cpp

@@ -9,5 +9,5 @@ UART _UART4_(UART4_TX_PIN, UART4_RX_PIN);
 #endif
 
 #if SERIAL_HOWMANY > 4
-UART _UART5_(UART5_TX_PIN, UART5_RX_PIN);
+UART _UART5_(UART5_TX_PIN, UART5_RX_PIN, UART5_RTS_PIN, UART5_CTS_PIN);
 #endif

variants/PORTENTA_C33/pins_arduino.h

@@ -80,6 +80,8 @@ static const uint8_t A7 = PIN_A7;
 #define UART4_RX_PIN        58
 #define UART5_TX_PIN        92
 #define UART5_RX_PIN        93
+#define UART5_RTS_PIN       94
+#define UART5_CTS_PIN       95
 
 /****** WIRE CORE DEFINES ******/