| 1 | /* |
| 2 | HardwareSerial_private.h - Hardware serial library for Wiring |
| 3 | Copyright (c) 2006 Nicholas Zambetti. All right reserved. |
| 4 | |
| 5 | This library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2.1 of the License, or (at your option) any later version. |
| 9 | |
| 10 | This library is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with this library; if not, write to the Free Software |
| 17 | Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 18 | |
| 19 | Modified 23 November 2006 by David A. Mellis |
| 20 | Modified 28 September 2010 by Mark Sproul |
| 21 | Modified 14 August 2012 by Alarus |
| 22 | */ |
| 23 |
|
| 24 | #include "wiring_private.h" |
| 25 |
|
| 26 | // this next line disables the entire HardwareSerial.cpp, |
| 27 | // this is so I can support Attiny series and any other chip without a uart |
| 28 | #if defined(HAVE_HWSERIAL0) || defined(HAVE_HWSERIAL1) || defined(HAVE_HWSERIAL2) || defined(HAVE_HWSERIAL3) |
| 29 |
|
| 30 | // Ensure that the various bit positions we use are available with a 0 |
| 31 | // postfix, so we can always use the values for UART0 for all UARTs. The |
| 32 | // alternative, passing the various values for each UART to the |
| 33 | // HardwareSerial constructor also works, but makes the code bigger and |
| 34 | // slower. |
| 35 | #if !defined(TXC0) |
| 36 | #if defined(TXC) |
| 37 | // Some chips like ATmega8 don't have UPE, only PE. The other bits are |
| 38 | // named as expected. |
| 39 | #if !defined(UPE) && defined(PE) |
| 40 | #define UPE PE |
| 41 | #endif |
| 42 | // On ATmega8, the uart and its bits are not numbered, so there is no TXC0 etc. |
| 43 | #define TXC0 TXC |
| 44 | #define RXEN0 RXEN |
| 45 | #define TXEN0 TXEN |
| 46 | #define RXCIE0 RXCIE |
| 47 | #define UDRIE0 UDRIE |
| 48 | #define U2X0 U2X |
| 49 | #define UPE0 UPE |
| 50 | #define UDRE0 UDRE |
| 51 | #elif defined(TXC1) |
| 52 | // Some devices have uart1 but no uart0 |
| 53 | #define TXC0 TXC1 |
| 54 | #define RXEN0 RXEN1 |
| 55 | #define TXEN0 TXEN1 |
| 56 | #define RXCIE0 RXCIE1 |
| 57 | #define UDRIE0 UDRIE1 |
| 58 | #define U2X0 U2X1 |
| 59 | #define UPE0 UPE1 |
| 60 | #define UDRE0 UDRE1 |
| 61 | #else |
| 62 | #error No UART found in HardwareSerial.cpp |
| 63 | #endif |
| 64 | #endif // !defined TXC0 |
| 65 | |
| 66 | // Check at compiletime that it is really ok to use the bit positions of |
| 67 | // UART0 for the other UARTs as well, in case these values ever get |
| 68 | // changed for future hardware. |
| 69 | #if defined(TXC1) && (TXC1 != TXC0 || RXEN1 != RXEN0 || RXCIE1 != RXCIE0 || \ |
| 70 | UDRIE1 != UDRIE0 || U2X1 != U2X0 || UPE1 != UPE0 || \ |
| 71 | UDRE1 != UDRE0) |
| 72 | #error "Not all bit positions for UART1 are the same as for UART0" |
| 73 | #endif |
| 74 | #if defined(TXC2) && (TXC2 != TXC0 || RXEN2 != RXEN0 || RXCIE2 != RXCIE0 || \ |
| 75 | UDRIE2 != UDRIE0 || U2X2 != U2X0 || UPE2 != UPE0 || \ |
| 76 | UDRE2 != UDRE0) |
| 77 | #error "Not all bit positions for UART2 are the same as for UART0" |
| 78 | #endif |
| 79 | #if defined(TXC3) && (TXC3 != TXC0 || RXEN3 != RXEN0 || RXCIE3 != RXCIE0 || \ |
| 80 | UDRIE3 != UDRIE0 || U3X3 != U3X0 || UPE3 != UPE0 || \ |
| 81 | UDRE3 != UDRE0) |
| 82 | #error "Not all bit positions for UART3 are the same as for UART0" |
| 83 | #endif |
| 84 |
|
| 85 | // Constructors //////////////////////////////////////////////////////////////// |
| 86 |
|
| 87 | HardwareSerial::HardwareSerial( |
| 88 | volatile uint8_t *ubrrh, volatile uint8_t *ubrrl, |
| 89 | volatile uint8_t *ucsra, volatile uint8_t *ucsrb, |
| 90 | volatile uint8_t *ucsrc, volatile uint8_t *udr) : |
| 91 | _ubrrh(ubrrh), _ubrrl(ubrrl), |
| 92 | _ucsra(ucsra), _ucsrb(ucsrb), _ucsrc(ucsrc), |
| 93 | _udr(udr), |
| 94 | _rx_buffer_head(0), _rx_buffer_tail(0), |
| 95 | _tx_buffer_head(0), _tx_buffer_tail(0) |
| 96 | { |
| 97 | } |
| 98 |
|
| 99 | // Actual interrupt handlers ////////////////////////////////////////////////////////////// |
| 100 |
|
| 101 | void HardwareSerial::_rx_complete_irq(void) |
| 102 | { |
| 103 | if (bit_is_clear(*_ucsra, UPE0)) { |
| 104 | // No Parity error, read byte and store it in the buffer if there is |
| 105 | // room |
| 106 | unsigned char c = *_udr; |
| 107 | rx_buffer_index_t i = (unsigned int)(_rx_buffer_head + 1) % SERIAL_RX_BUFFER_SIZE; |
| 108 |
|
| 109 | // if we should be storing the received character into the location |
| 110 | // just before the tail (meaning that the head would advance to the |
| 111 | // current location of the tail), we're about to overflow the buffer |
| 112 | // and so we don't write the character or advance the head. |
| 113 | if (i != _rx_buffer_tail) { |
| 114 | _rx_buffer[_rx_buffer_head] = c; |
| 115 | _rx_buffer_head = i; |
| 116 | } |
| 117 | } else { |
| 118 | // Parity error, read byte but discard it |
| 119 | *_udr; |
| 120 | }; |
| 121 | } |
| 122 |
|
| 123 | #endif // whole file |
| 124 |
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