AP_HAL: remove unused peek() interface from UART drivers

this is a bit tricky to implement on some platforms, and is unused
anyway

libraries/AP_HAL/utility/Stream.h

@@ -15,10 +15,9 @@ public:
      * FastSerial library. As far as concerns go, it belongs with available() */
     virtual int16_t txspace() = 0;
 
-    /* return value for read() and peek() :
+    /* return value for read():
      * -1 if nothing available, uint8_t value otherwise. */
     virtual int16_t read() = 0;
-    virtual int16_t peek() = 0;
 
 };
 

libraries/AP_HAL_AVR/Console.cpp

@@ -77,10 +77,6 @@ int16_t AVRConsoleDriver::read() {
     return _base_uart->read();
 }
 
-int16_t AVRConsoleDriver::peek() {
-    return _base_uart->peek();
-}
-
 // Print method implementations /////////////////////////////////////////
 
 size_t AVRConsoleDriver::write(uint8_t c) {

libraries/AP_HAL_AVR/Console.h

@@ -30,7 +30,6 @@ public:
     int16_t available();
     int16_t txspace();
     int16_t read();
-    int16_t peek();
 
     /* Implementations of Print virtual methods */
     size_t write(uint8_t c);

libraries/AP_HAL_AVR/UARTDriver.cpp

@@ -150,16 +150,6 @@ int16_t AVRUARTDriver::read(void) {
 	return (c);
 }
 
-int16_t AVRUARTDriver::peek(void) {
-
-	// if the head and tail are equal, the buffer is empty
-	if (!_open || (_rxBuffer->head == _rxBuffer->tail))
-		return (-1);
-
-	// pull character from tail
-	return (_rxBuffer->bytes[_rxBuffer->tail]);
-}
-
 void AVRUARTDriver::flush(void) {
 	// don't reverse this or there may be problems if the RX interrupt
 	// occurs after reading the value of _rxBuffer->head but before writing

libraries/AP_HAL_AVR/UARTDriver.h

@@ -55,7 +55,6 @@ public:
     int16_t available();
     int16_t txspace();
     int16_t read();
-    int16_t peek();
 
     /* Implementations of Print virtual methods */
     size_t write(uint8_t c);

libraries/AP_HAL_AVR_SITL/Console.cpp

@@ -95,11 +95,6 @@ int16_t SITLConsoleDriver::read()
     return _base_uart->read();
 }
 
-int16_t SITLConsoleDriver::peek() 
-{
-        return _base_uart->peek();
-}
-
 // Print method implementations /////////////////////////////////////////
 
 size_t SITLConsoleDriver::write(uint8_t c) 

libraries/AP_HAL_AVR_SITL/Console.h

@@ -32,7 +32,6 @@ public:
     int16_t available();
     int16_t txspace();
     int16_t read();
-    int16_t peek();
 
     /* Implementations of Print virtual methods */
     size_t write(uint8_t c);

libraries/AP_HAL_AVR_SITL/UARTDriver.cpp

@@ -139,11 +139,6 @@ int16_t SITLUARTDriver::read(void)
     return -1;
 }
 
-int16_t SITLUARTDriver::peek(void) 
-{
-    return -1;
-}
-
 void SITLUARTDriver::flush(void) 
 {
 }

libraries/AP_HAL_AVR_SITL/UARTDriver.h

@@ -53,7 +53,6 @@ public:
     int16_t available();
     int16_t txspace();
     int16_t read();
-    int16_t peek();
 
     /* Implementations of Print virtual methods */
     size_t write(uint8_t c);

libraries/AP_HAL_Empty/Console.cpp

@@ -66,10 +66,6 @@ int16_t EmptyConsoleDriver::read() {
     return _d->read();
 }
 
-int16_t EmptyConsoleDriver::peek() {
-    return _d->peek();
-}
-
 size_t EmptyConsoleDriver::write(uint8_t c) {
     return _d->write(c);
 }

libraries/AP_HAL_Empty/Console.h

@@ -23,7 +23,6 @@ public:
     int16_t available();
     int16_t txspace();
     int16_t read();
-    int16_t peek();
 
     size_t write(uint8_t c);
 private:

libraries/AP_HAL_Empty/UARTDriver.cpp

@@ -25,7 +25,6 @@ void EmptyUARTDriver::vprintf_P(const prog_char *pstr, va_list ap) {}
 int16_t EmptyUARTDriver::available() { return 0; }
 int16_t EmptyUARTDriver::txspace() { return 1; }
 int16_t EmptyUARTDriver::read() { return -1; }
-int16_t EmptyUARTDriver::peek() { return -1; }
 
 /* Empty implementations of Print virtual methods */
 size_t EmptyUARTDriver::write(uint8_t c) { return 0; }

libraries/AP_HAL_Empty/UARTDriver.h

@@ -29,7 +29,6 @@ public:
     int16_t available();
     int16_t txspace();
     int16_t read();
-    int16_t peek();
 
     /* Empty implementations of Print virtual methods */
     size_t write(uint8_t c);

libraries/AP_HAL_PX4/Console.cpp

@@ -71,10 +71,6 @@ int16_t PX4ConsoleDriver::read() {
 	return _uart->read();
 }
 
-int16_t PX4ConsoleDriver::peek() {
-	return _uart->peek();
-}
-
 size_t PX4ConsoleDriver::write(uint8_t c) {
 	return _uart->write(c);
 }

libraries/AP_HAL_PX4/Console.h

@@ -24,7 +24,6 @@ public:
     int16_t available();
     int16_t txspace();
     int16_t read();
-    int16_t peek();
 
     size_t write(uint8_t c);
 

libraries/AP_HAL_PX4/UARTDriver.cpp

@@ -130,10 +130,6 @@ int16_t PX4UARTDriver::read() {
 	return -1;
 }
 
-int16_t PX4UARTDriver::peek() { 
-	return -1;
-}
-
 /* PX4 implementations of Print virtual methods */
 size_t PX4UARTDriver::write(uint8_t c) { 
 	if (!_initialised) {

libraries/AP_HAL_PX4/UARTDriver.h

@@ -29,7 +29,6 @@ public:
     int16_t available();
     int16_t txspace();
     int16_t read();
-    int16_t peek();
 
     /* PX4 implementations of Print virtual methods */
     size_t write(uint8_t c);

libraries/AP_HAL_SMACCM/Console.cpp

@@ -125,15 +125,6 @@ int16_t SMACCMConsoleDriver::read()
   }
 }
 
-int16_t SMACCMConsoleDriver::peek()
-{
-  if (_user_backend) {
-    return _rxbuf.peek();
-  } else {
-    return _d->peek();
-  }
-}
-
 size_t SMACCMConsoleDriver::write(uint8_t c)
 {
   if (_user_backend) {
@@ -192,15 +183,6 @@ int16_t SMACCMConsoleDriver::Buffer::pop()
   return (int16_t) b;
 }
 
-int16_t SMACCMConsoleDriver::Buffer::peek()
-{
-  if ( _tail == _head ) {
-    return -1;
-  }
-  uint8_t b = _bytes[_tail];
-  return (int16_t) b;
-}
-
 uint16_t SMACCMConsoleDriver::Buffer::bytes_used()
 {
   return ((_head - _tail) & _mask);

libraries/AP_HAL_SMACCM/Console.h

@@ -32,7 +32,6 @@ public:
     int16_t available();
     int16_t txspace();
     int16_t read();
-    int16_t peek();
 
     size_t write(uint8_t c);
 private:
@@ -44,7 +43,6 @@ private:
         bool allocate(uint16_t size);
         bool push(uint8_t b);
         int16_t  pop();
-        int16_t  peek();
 
         uint16_t bytes_free();
         uint16_t bytes_used();

libraries/AP_HAL_SMACCM/UARTDriver.cpp

@@ -146,19 +146,6 @@ int16_t SMACCMUARTDriver::read()
   return (int16_t)c;
 }
 
-int16_t SMACCMUARTDriver::peek()
-{
-  uint8_t c;
-
-  if (m_dev == NULL)
-    return -1;
-
-  if (!usart_peek(m_dev, &c))
-    return -1;
-
-  return (int16_t)c;
-}
-
 /* SMACCM implementations of Print virtual methods */
 size_t SMACCMUARTDriver::write(uint8_t c)
 {

libraries/AP_HAL_SMACCM/UARTDriver.h

@@ -36,7 +36,6 @@ public:
   int16_t available();
   int16_t txspace();
   int16_t read();
-  int16_t peek();
 
   /* SMACCM implementations of Print virtual methods */
   size_t write(uint8_t c);