Add uart flow control (take 2)

firmware/app_layer_v1/features.c

@@ -57,7 +57,10 @@ static void PinsInit() {
     SetPinDigitalIn(i, 0);    // all other pins: input, no-pull
   }
   for (i = 0; i < NUM_UART_MODULES; ++i) {
-    SetPinUart(0, i, 0, 0);  // UART RX disabled
+    SetPinUart(0, i, 0, 0, 0);  // UART RX disabled
+    // Why isn't TX reset?
+    SetPinUart(0, i, 0, 1, 0);  // UART CTS disabled
+    SetPinUart(0, i, 1, 1, 0);  // UART RTS disabled
   }
   // clear and enable global CN interrupts
   _CNIF = 0;
@@ -110,33 +113,59 @@ void SetPinPwm(int pin, int pwm_num, int enable) {
   PinSetRpor(pin, enable ? (pwm_num == 8 ? 35 : 18 + pwm_num) : 0);
 }
 
-void SetPinUart(int pin, int uart_num, int dir, int enable) {
-  log_printf("SetPinUart(%d, %d, %d, %d)", pin, uart_num, dir, enable);
+void SetPinUart(int pin, int uart_num, int dir, int flow, int enable) {
+  log_printf("SetPinUart(%d, %d, %d, %d, %d)", pin, uart_num, dir, flow, enable);
   SAVE_PIN_FOR_LOG(pin);
   SAVE_UART_FOR_LOG(uart_num);
-  if (dir) {
-    // TX
-    const BYTE rp[] = { 3, 5, 28, 30 };
-    PinSetRpor(pin, enable ? rp[uart_num] : 0);
+  if (!flow) {
+    if (dir) {
+      // TX
+      const BYTE rp[] = { 3, 5, 28, 30 };
+      PinSetRpor(pin, enable ? rp[uart_num] : 0);
+    } else {
+      // RX
+      int rpin = enable ? PinToRpin(pin) : 0x3F;
+      switch (uart_num) {
+        case 0:
+          _U1RXR = rpin;
+          break;
+
+        case 1:
+          _U2RXR = rpin;
+          break;
+
+        case 2:
+          _U3RXR = rpin;
+          break;
+
+        case 3:
+          _U4RXR = rpin;
+          break;
+      }
+    }
   } else {
-    // RX
-    int rpin = enable ? PinToRpin(pin) : 0x3F;
-    switch (uart_num) {
-      case 0:
-        _U1RXR = rpin;
-        break;
+    if (dir) {  // RTS output
+      const BYTE rp[] = { 4, 6, 29, 31 };
+      PinSetRpor(pin, enable ? rp[uart_num] : 0);
+    } else {    // CTS input
+      int rpin = enable ? PinToRpin(pin) : 0x3F;
+      switch (uart_num) {
+        case 0:
+          _U1CTSR = rpin;
+          break;
 
-      case 1:
-        _U2RXR = rpin;
-        break;
+        case 1:
+          _U2CTSR = rpin;
+          break;
 
-      case 2:
-        _U3RXR = rpin;
-        break;
+        case 2:
+          _U3CTSR = rpin;
+          break;
 
-      case 3:
-        _U4RXR = rpin;
-        break;
+        case 3:
+          _U4CTSR = rpin;
+          break;
+      }
     }
   }
 }

firmware/app_layer_v1/features.h

@@ -36,7 +36,7 @@ void SetPinDigitalOut(int pin, int value, int open_drain);
 void SetPinDigitalIn(int pin, int pull);
 void SetPinAnalogIn(int pin);
 void SetPinPwm(int pin, int pwm_num, int enable);
-void SetPinUart(int pin, int uart_num, int dir, int enable);
+void SetPinUart(int pin, int uart_num, int dir, int flow, int enable);
 void SetPinSpi(int pin, int spi_num, int mode, int enable);
 void SetPinInCap(int pin, int incap_num, int enable);
 void HardReset();

firmware/app_layer_v1/protocol.c

@@ -335,7 +335,8 @@ static BOOL MessageDone() {
                  rx_msg.args.uart_config.rate,
                  rx_msg.args.uart_config.speed4x,
                  rx_msg.args.uart_config.two_stop_bits,
-                 rx_msg.args.uart_config.parity);
+                 rx_msg.args.uart_config.parity,
+                 rx_msg.args.uart_config.flow);
       break;
 
     case SET_PIN_UART:
@@ -344,6 +345,7 @@ static BOOL MessageDone() {
       SetPinUart(rx_msg.args.set_pin_uart.pin,
                  rx_msg.args.set_pin_uart.uart_num,
                  rx_msg.args.set_pin_uart.dir,
+                 rx_msg.args.set_pin_uart.flow,
                  rx_msg.args.set_pin_uart.enable);
       break;
 

firmware/app_layer_v1/protocol_defs.h

@@ -160,12 +160,19 @@ typedef struct PACKED {
   BYTE data[0];
 } UART_DATA_ARGS;
 
+typedef enum {
+  FLOW_NONE,
+  FLOW_IRDA,
+  FLOW_RTSCTS,
+  FLOW_RS485,
+} UART_FLOW_MODE;
+
 // uart config
 typedef struct PACKED {
   BYTE parity : 2;
   BYTE two_stop_bits : 1;
   BYTE speed4x : 1;
-  BYTE : 2;
+  BYTE flow : 2;
   BYTE uart_num : 2;
   WORD rate;
 } UART_CONFIG_ARGS;
@@ -182,7 +189,8 @@ typedef struct PACKED {
   BYTE pin : 6;
   BYTE : 2;
   BYTE uart_num : 2;
-  BYTE : 4;
+  BYTE : 3;
+  BYTE flow : 1;
   BYTE dir : 1;
   BYTE enable : 1;
 } SET_PIN_UART_ARGS;

firmware/app_layer_v1/uart.c

@@ -64,12 +64,13 @@ DEFINE_REG_SETTERS_1B(NUM_UART_MODULES, _U, TXIE)
 DEFINE_REG_SETTERS_1B(NUM_UART_MODULES, _U, TXIF)
 DEFINE_REG_SETTERS_1B(NUM_UART_MODULES, _U, TXIP)
 
-static void UARTConfigInternal(int uart_num, int rate, int speed4x, int two_stop_bits, int parity, int external);
+static void UARTConfigInternal(int uart_num, int rate, int speed4x, int two_stop_bits, int parity,
+                               int flow_mode, int external);
 
 void UARTInit() {
   int i;
   for (i = 0; i < NUM_UART_MODULES; ++i) {
-    UARTConfigInternal(i, 0, 0, 0, 0, 0);
+    UARTConfigInternal(i, 0, 0, 0, 0, 0, 0);
     Set_URXIP[i](4);  // RX int. priority 4
     Set_UTXIP[i](4);  // TX int. priority 4
   }
@@ -83,12 +84,15 @@ static inline void UARTSendStatus(int uart_num, int enabled) {
   AppProtocolSendMessage(&msg);
 }
 
-static void UARTConfigInternal(int uart_num, int rate, int speed4x, int two_stop_bits, int parity, int external) {
+static void UARTConfigInternal(int uart_num, int rate, int speed4x, int two_stop_bits, int parity,
+                               int flow_mode, int external) {
   volatile UART* regs = uart_reg[uart_num];
   UART_STATE* uart = &uarts[uart_num];
+  // for irda, idle state is 0 for both RX and TX (i.e. for TFBS4711)
+  const int flow_map[] = {0x0000, 0x1010, 0x0200, 0x0a00};  // none, irda, rtscts, rs485/simplex
   if (external) {
-    log_printf("UARTConfig(%d, %d, %d, %d, %d)", uart_num, rate, speed4x,
-               two_stop_bits, parity);
+    log_printf("UARTConfig(%d, %d, %d, %d, %d, %d)", uart_num, rate, speed4x,
+               two_stop_bits, parity, flow_mode);
   }
   SAVE_UART_FOR_LOG(uart_num);
   Set_URXIE[uart_num](0);  // disable RX int.
@@ -106,7 +110,8 @@ static void UARTConfigInternal(int uart_num, int rate, int speed4x, int two_stop
     Set_URXIF[uart_num](0);  // clear RX int.
     Set_UTXIF[uart_num](0);  // clear TX int.
     Set_URXIE[uart_num](1);  // enable RX int.
-    regs->uxmode = 0x8000 | (speed4x ? 0x0008 : 0x0000) | two_stop_bits | (parity << 1);  // enable
+    regs->uxmode = 0x8000 | flow_map[flow_mode & 0x3] \
+        | (speed4x ? 0x0008 : 0x0000) | two_stop_bits | (parity << 1);  // enable
     regs->uxsta = 0x8400;  // IRQ when TX buffer is empty, enable TX, IRQ when character received.
     uart->num_tx_since_last_report = TX_BUF_SIZE;
   } else {
@@ -116,8 +121,8 @@ static void UARTConfigInternal(int uart_num, int rate, int speed4x, int two_stop
   }
 }
 
-void UARTConfig(int uart_num, int rate, int speed4x, int two_stop_bits, int parity) {
-  UARTConfigInternal(uart_num, rate, speed4x, two_stop_bits, parity, 1);
+void UARTConfig(int uart_num, int rate, int speed4x, int two_stop_bits, int parity, int flow_mode) {
+  UARTConfigInternal(uart_num, rate, speed4x, two_stop_bits, parity, flow_mode, 1);
 }
 
 
@@ -225,4 +230,3 @@ void UARTTransmit(int uart_num, const void* data, int size) {
 #if NUM_UART_MODULES >= 4
   DEFINE_INTERRUPT_HANDLERS(4)
 #endif
-

firmware/app_layer_v1/uart.h

@@ -32,7 +32,7 @@
 
 void UARTInit();
 void UARTConfig(int uart_num, int rate, int speed4x, int two_stop_bits,
-                int parity);
+                int parity, int flow_mode);
 void UARTTransmit(int uart_num, const void* data, int size);
 void UARTTasks();
 

software/IOIOLib/src/ioio/lib/api/IOIO.java

@@ -485,6 +485,17 @@ public PulseInput openPulseInput(int pin, PulseMode mode)
 	 *            The parity mode, as in {@link Parity}.
 	 * @param stopbits
 	 *            Number of stop bits, as in {@link StopBits}.
+	 * @param mode
+	 *            Flow control mode, as in {@link FlowMode}.  This can by FLOW_NONE,
+	 *            FLOW_IRDA, FLOW_RTSCTS, or FLOW_RS485.
+	 * @param rts
+	 *            Pin number specification for the RTS (Request To Send) output pin.
+	 *            If the flow control mode is not FLOW_RTSCTS or FLOW_RS485, then
+	 *            this parameter is ignored.
+	 * @param cts
+	 *            Pin number specification for the CTS (Clear To Send) input pin.
+	 *            If the flow control mode is not FLOW_RTSCTS or FLOW_RS485, then
+	 *            this parameter is ignored.
 	 * @return Interface of the assigned module.
 	 * @throws ConnectionLostException
 	 *             Connection was lost before or during the execution of this
@@ -496,20 +507,34 @@ public PulseInput openPulseInput(int pin, PulseMode mode)
 	 * @see Uart
 	 */
 	public Uart openUart(DigitalInput.Spec rx, DigitalOutput.Spec tx, int baud,
-			Parity parity, StopBits stopbits) throws ConnectionLostException;
+			Parity parity, StopBits stopbits, Uart.FlowMode mode, DigitalOutput.Spec rts,
+			DigitalInput.Spec cts) throws ConnectionLostException;
 
 	/**
 	 * Shorthand for
-	 * {@link #openUart(DigitalInput.Spec, DigitalOutput.Spec, int, Uart.Parity, Uart.StopBits)}
+	 * {@link #openUart(DigitalInput.Spec, DigitalOutput.Spec, int, Uart.Parity, Uart.StopBits, Uart.FlowMode, DigitalOutput.Spec, DigitalInput.Spec)}
 	 * , where the input pins use their default specs. {@link #INVALID_PIN} can
-	 * be used on either pin if a TX- or RX-only UART is needed.
+	 * be used on either pin if a TX- or RX-only UART is needed.  The flow mode is FLOW_NONE.
 	 * 
 	 * @see #openUart(DigitalInput.Spec, DigitalOutput.Spec, int, Uart.Parity,
-	 *      Uart.StopBits)
+	 *      Uart.StopBits, Uart.FlowMode, DigitalOutput.Spec, DigitalInput.Spec)
 	 */
 	public Uart openUart(int rx, int tx, int baud, Parity parity,
 			StopBits stopbits) throws ConnectionLostException;
 
+	/**
+	 * Shorthand for
+	 * {@link #openUart(DigitalInput.Spec, DigitalOutput.Spec, int, Uart.Parity, Uart.StopBits, Uart.FlowMode, DigitalOutput.Spec, DigitalInput.Spec)}
+	 * , where the input pins use their default specs. {@link #INVALID_PIN} can
+	 * be used on either pin if a TX- or RX-only UART is needed.
+	 * 
+	 * @see #openUart(DigitalInput.Spec, DigitalOutput.Spec, int, Uart.Parity,
+	 *      Uart.StopBits, Uart.FlowMode, DigitalOutput.Spec, DigitalInput.Spec)
+	 */
+    public Uart openUart(int rx, int tx, int baud, Uart.Parity parity,
+        Uart.StopBits stopbits, Uart.FlowMode mode, int rts,
+        int cts) throws ConnectionLostException;
+
 	/**
 	 * Open a SPI master module, enabling communication with multiple
 	 * SPI-enabled slave modules.

software/IOIOLib/src/ioio/lib/api/Uart.java

@@ -40,7 +40,7 @@
  * asynchronous point-to-point data transfer. It typically serves for opening
  * consoles or as a basis for higher-level protocols, such as MIDI, RS-232 and
  * RS-485. Uart instances are obtained by calling
- * {@link IOIO#openUart(DigitalInput.Spec, DigitalOutput.Spec, int, Uart.Parity, Uart.StopBits)}.
+ * {@link IOIO#openUart(DigitalInput.Spec, DigitalOutput.Spec, int, Uart.Parity, Uart.StopBits, Uart.FlowMode, DigitalOutput.Spec, DigitalInput.Spec)}.
  * <p>
  * The UART protocol is completely symmetric - there is no "master" and "slave"
  * at this layer. Each end may send any number of bytes at arbitrary times,
@@ -70,7 +70,7 @@
  * </pre>
  * 
  * @see IOIO#openUart(DigitalInput.Spec, DigitalOutput.Spec, int, Uart.Parity,
- *      Uart.StopBits)
+ *      Uart.StopBits, Uart.FlowMode, DigitalOutput.Spec, DigitalInput.Spec)
  */
 public interface Uart extends Closeable {
 	/** Parity-bit mode. */
@@ -91,6 +91,19 @@ enum StopBits {
 		TWO
 	}
 
+	/** Flow control line modes */
+	enum FlowMode {
+		/** No flow control. */
+		NONE,
+		/** Use IRDA encode/decode and no flow control. */
+		IRDA,
+		/** Use RTS/CTS lines for flow control. */
+		RTSCTS,
+		/** Raise RTS when transmitting (for RS-485 transmit enable).
+		Note that CTS should be connected to RTS. */
+		RS485,
+	}
+
 	/**
 	 * Gets the input stream.
 	 *