Merged upstream arduino branch

1 files changed, 93 insertions, 17 deletions

diff --git a/cores/arduino/HardwareSerial.cpp b/cores/arduino/HardwareSerial.cpp
index f40ddee..2e64acb 100644
--- a/cores/arduino/HardwareSerial.cpp
+++ b/cores/arduino/HardwareSerial.cpp
@@ -18,6 +18,7 @@
   
   Modified 23 November 2006 by David A. Mellis
   Modified 28 September 2010 by Mark Sproul
+  Modified 14 August 2012 by Alarus
 */
 
 #include <stdlib.h>
@@ -109,13 +110,22 @@ inline void store_char(unsigned char c, ring_buffer *buffer)
 #endif
   {
   #if defined(UDR0)
-    unsigned char c  =  UDR0;
+    if (bit_is_clear(UCSR0A, UPE0)) {
+      unsigned char c = UDR0;
+      store_char(c, &rx_buffer);
+    } else {
+      unsigned char c = UDR0;
+    };
   #elif defined(UDR)
-    unsigned char c  =  UDR;
+    if (bit_is_clear(UCSRA, PE)) {
+      unsigned char c = UDR;
+      store_char(c, &rx_buffer);
+    } else {
+      unsigned char c = UDR;
+    };
   #else
     #error UDR not defined
   #endif
-    store_char(c, &rx_buffer);
   }
 #endif
 #endif
@@ -126,8 +136,12 @@ inline void store_char(unsigned char c, ring_buffer *buffer)
   #define serialEvent1_implemented
   SIGNAL(USART1_RX_vect)
   {
-    unsigned char c = UDR1;
-    store_char(c, &rx_buffer1);
+    if (bit_is_clear(UCSR1A, UPE1)) {
+      unsigned char c = UDR1;
+      store_char(c, &rx_buffer1);
+    } else {
+      unsigned char c = UDR1;
+    };
   }
 #elif defined(SIG_USART1_RECV)
   #error SIG_USART1_RECV
@@ -139,8 +153,12 @@ inline void store_char(unsigned char c, ring_buffer *buffer)
   #define serialEvent2_implemented
   SIGNAL(USART2_RX_vect)
   {
-    unsigned char c = UDR2;
-    store_char(c, &rx_buffer2);
+    if (bit_is_clear(UCSR2A, UPE2)) {
+      unsigned char c = UDR2;
+      store_char(c, &rx_buffer2);
+    } else {
+      unsigned char c = UDR2;
+    };
   }
 #elif defined(SIG_USART2_RECV)
   #error SIG_USART2_RECV
@@ -152,8 +170,12 @@ inline void store_char(unsigned char c, ring_buffer *buffer)
   #define serialEvent3_implemented
   SIGNAL(USART3_RX_vect)
   {
-    unsigned char c = UDR3;
-    store_char(c, &rx_buffer3);
+    if (bit_is_clear(UCSR3A, UPE3)) {
+      unsigned char c = UDR3;
+      store_char(c, &rx_buffer3);
+    } else {
+      unsigned char c = UDR3;
+    };
   }
 #elif defined(SIG_USART3_RECV)
   #error SIG_USART3_RECV
@@ -274,7 +296,7 @@ ISR(USART3_UDRE_vect)
 HardwareSerial::HardwareSerial(ring_buffer *rx_buffer, ring_buffer *tx_buffer,
   volatile uint8_t *ubrrh, volatile uint8_t *ubrrl,
   volatile uint8_t *ucsra, volatile uint8_t *ucsrb,
-  volatile uint8_t *udr,
+  volatile uint8_t *ucsrc, volatile uint8_t *udr,
   uint8_t rxen, uint8_t txen, uint8_t rxcie, uint8_t udrie, uint8_t u2x)
 {
   _rx_buffer = rx_buffer;
@@ -283,6 +305,7 @@ HardwareSerial::HardwareSerial(ring_buffer *rx_buffer, ring_buffer *tx_buffer,
   _ubrrl = ubrrl;
   _ucsra = ucsra;
   _ucsrb = ucsrb;
+  _ucsrc = ucsrc;
   _udr = udr;
   _rxen = rxen;
   _txen = txen;
@@ -327,6 +350,55 @@ try_again:
   *_ubrrh = baud_setting >> 8;
   *_ubrrl = baud_setting;
 
+  transmitting = false;
+
+  sbi(*_ucsrb, _rxen);
+  sbi(*_ucsrb, _txen);
+  sbi(*_ucsrb, _rxcie);
+  cbi(*_ucsrb, _udrie);
+}
+
+void HardwareSerial::begin(unsigned long baud, byte config)
+{
+  uint16_t baud_setting;
+  uint8_t current_config;
+  bool use_u2x = true;
+
+#if F_CPU == 16000000UL
+  // hardcoded exception for compatibility with the bootloader shipped
+  // with the Duemilanove and previous boards and the firmware on the 8U2
+  // on the Uno and Mega 2560.
+  if (baud == 57600) {
+    use_u2x = false;
+  }
+#endif
+
+try_again:
+  
+  if (use_u2x) {
+    *_ucsra = 1 << _u2x;
+    baud_setting = (F_CPU / 4 / baud - 1) / 2;
+  } else {
+    *_ucsra = 0;
+    baud_setting = (F_CPU / 8 / baud - 1) / 2;
+  }
+  
+  if ((baud_setting > 4095) && use_u2x)
+  {
+    use_u2x = false;
+    goto try_again;
+  }
+
+  // assign the baud_setting, a.k.a. ubbr (USART Baud Rate Register)
+  *_ubrrh = baud_setting >> 8;
+  *_ubrrl = baud_setting;
+
+  //set the data bits, parity, and stop bits
+#if defined(__AVR_ATmega8__)
+  config |= 0x80; // select UCSRC register (shared with UBRRH)
+#endif
+  *_ucsrc = config;
+  
   sbi(*_ucsrb, _rxen);
   sbi(*_ucsrb, _txen);
   sbi(*_ucsrb, _rxcie);
@@ -376,8 +448,9 @@ int HardwareSerial::read(void)
 
 void HardwareSerial::flush()
 {
-  while (_tx_buffer->head != _tx_buffer->tail)
-    ;
+  // UDR is kept full while the buffer is not empty, so TXC triggers when EMPTY && SENT
+  while (transmitting && ! (*_ucsra & _BV(TXC0)));
+  transmitting = false;
 }
 
 size_t HardwareSerial::write(uint8_t c)
@@ -394,6 +467,9 @@ size_t HardwareSerial::write(uint8_t c)
   _tx_buffer->head = i;
 	
   sbi(*_ucsrb, _udrie);
+  // clear the TXC bit -- "can be cleared by writing a one to its bit location"
+  transmitting = true;
+  sbi(*_ucsra, TXC0);
   
   return 1;
 }
@@ -405,9 +481,9 @@ HardwareSerial::operator bool() {
 // Preinstantiate Objects //////////////////////////////////////////////////////
 
 #if defined(UBRRH) && defined(UBRRL)
-  HardwareSerial Serial(&rx_buffer, &tx_buffer, &UBRRH, &UBRRL, &UCSRA, &UCSRB, &UDR, RXEN, TXEN, RXCIE, UDRIE, U2X);
+  HardwareSerial Serial(&rx_buffer, &tx_buffer, &UBRRH, &UBRRL, &UCSRA, &UCSRB, &UCSRC, &UDR, RXEN, TXEN, RXCIE, UDRIE, U2X);
 #elif defined(UBRR0H) && defined(UBRR0L)
-  HardwareSerial Serial(&rx_buffer, &tx_buffer, &UBRR0H, &UBRR0L, &UCSR0A, &UCSR0B, &UDR0, RXEN0, TXEN0, RXCIE0, UDRIE0, U2X0);
+  HardwareSerial Serial(&rx_buffer, &tx_buffer, &UBRR0H, &UBRR0L, &UCSR0A, &UCSR0B, &UCSR0C, &UDR0, RXEN0, TXEN0, RXCIE0, UDRIE0, U2X0);
 #elif defined(USBCON)
   // do nothing - Serial object and buffers are initialized in CDC code
 #else
@@ -415,13 +491,13 @@ HardwareSerial::operator bool() {
 #endif
 
 #if defined(UBRR1H)
-  HardwareSerial Serial1(&rx_buffer1, &tx_buffer1, &UBRR1H, &UBRR1L, &UCSR1A, &UCSR1B, &UDR1, RXEN1, TXEN1, RXCIE1, UDRIE1, U2X1);
+  HardwareSerial Serial1(&rx_buffer1, &tx_buffer1, &UBRR1H, &UBRR1L, &UCSR1A, &UCSR1B, &UCSR1C, &UDR1, RXEN1, TXEN1, RXCIE1, UDRIE1, U2X1);
 #endif
 #if defined(UBRR2H)
-  HardwareSerial Serial2(&rx_buffer2, &tx_buffer2, &UBRR2H, &UBRR2L, &UCSR2A, &UCSR2B, &UDR2, RXEN2, TXEN2, RXCIE2, UDRIE2, U2X2);
+  HardwareSerial Serial2(&rx_buffer2, &tx_buffer2, &UBRR2H, &UBRR2L, &UCSR2A, &UCSR2B, &UCSR2C, &UDR2, RXEN2, TXEN2, RXCIE2, UDRIE2, U2X2);
 #endif
 #if defined(UBRR3H)
-  HardwareSerial Serial3(&rx_buffer3, &tx_buffer3, &UBRR3H, &UBRR3L, &UCSR3A, &UCSR3B, &UDR3, RXEN3, TXEN3, RXCIE3, UDRIE3, U2X3);
+  HardwareSerial Serial3(&rx_buffer3, &tx_buffer3, &UBRR3H, &UBRR3L, &UCSR3A, &UCSR3B, &UCSR3C, &UDR3, RXEN3, TXEN3, RXCIE3, UDRIE3, U2X3);
 #endif
 
 #endif // whole file