diff options
Diffstat (limited to 'drivers/avr/uart.c')
| -rw-r--r-- | drivers/avr/uart.c | 170 |
1 files changed, 0 insertions, 170 deletions
diff --git a/drivers/avr/uart.c b/drivers/avr/uart.c deleted file mode 100644 index c6abcb6fe0..0000000000 --- a/drivers/avr/uart.c +++ /dev/null @@ -1,170 +0,0 @@ -/* UART Example for Teensy USB Development Board - * http://www.pjrc.com/teensy/ - * Copyright (c) 2009 PJRC.COM, LLC - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this software and associated documentation files (the "Software"), to deal - * in the Software without restriction, including without limitation the rights - * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell - * copies of the Software, and to permit persons to whom the Software is - * furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, - * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN - * THE SOFTWARE. - */ - -// Version 1.0: Initial Release -// Version 1.1: Add support for Teensy 2.0, minor optimizations - -#include <avr/io.h> -#include <avr/interrupt.h> - -#include "uart.h" - -#if defined(__AVR_AT90USB162__) || defined(__AVR_ATmega16U2__) || defined(__AVR_ATmega32U2__) || defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__) || defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB647__) || defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB1287__) -# define UDRn UDR1 -# define UBRRnL UBRR1L -# define UCSRnA UCSR1A -# define UCSRnB UCSR1B -# define UCSRnC UCSR1C -# define U2Xn U2X1 -# define RXENn RXEN1 -# define TXENn TXEN1 -# define RXCIEn RXCIE1 -# define UCSZn1 UCSZ11 -# define UCSZn0 UCSZ10 -# define UDRIEn UDRIE1 -# define USARTn_UDRE_vect USART1_UDRE_vect -# define USARTn_RX_vect USART1_RX_vect -#elif defined(__AVR_ATmega32A__) -# define UDRn UDR -# define UBRRnL UBRRL -# define UCSRnA UCSRA -# define UCSRnB UCSRB -# define UCSRnC UCSRC -# define U2Xn U2X -# define RXENn RXEN -# define TXENn TXEN -# define RXCIEn RXCIE -# define UCSZn1 UCSZ1 -# define UCSZn0 UCSZ0 -# define UDRIEn UDRIE -# define USARTn_UDRE_vect USART_UDRE_vect -# define USARTn_RX_vect USART_RX_vect -#elif defined(__AVR_ATmega328__) || defined(__AVR_ATmega328P__) -# define UDRn UDR0 -# define UBRRnL UBRR0L -# define UCSRnA UCSR0A -# define UCSRnB UCSR0B -# define UCSRnC UCSR0C -# define U2Xn U2X0 -# define RXENn RXEN0 -# define TXENn TXEN0 -# define RXCIEn RXCIE0 -# define UCSZn1 UCSZ01 -# define UCSZn0 UCSZ00 -# define UDRIEn UDRIE0 -# define USARTn_UDRE_vect USART_UDRE_vect -# define USARTn_RX_vect USART_RX_vect -#endif - -// These buffers may be any size from 2 to 256 bytes. -#define RX_BUFFER_SIZE 64 -#define TX_BUFFER_SIZE 256 - -static volatile uint8_t tx_buffer[TX_BUFFER_SIZE]; -static volatile uint8_t tx_buffer_head; -static volatile uint8_t tx_buffer_tail; -static volatile uint8_t rx_buffer[RX_BUFFER_SIZE]; -static volatile uint8_t rx_buffer_head; -static volatile uint8_t rx_buffer_tail; - -// Initialize the UART -void uart_init(uint32_t baud) { - cli(); - UBRRnL = (F_CPU / 4 / baud - 1) / 2; - UCSRnA = (1 << U2Xn); - UCSRnB = (1 << RXENn) | (1 << TXENn) | (1 << RXCIEn); - UCSRnC = (1 << UCSZn1) | (1 << UCSZn0); - tx_buffer_head = tx_buffer_tail = 0; - rx_buffer_head = rx_buffer_tail = 0; - sei(); -} - -// Transmit a byte -void uart_putchar(uint8_t c) { - uint8_t i; - - i = tx_buffer_head + 1; - if (i >= TX_BUFFER_SIZE) i = 0; - // return immediately to avoid deadlock when interrupt is disabled(called from ISR) - if (tx_buffer_tail == i && (SREG & (1 << SREG_I)) == 0) return; - while (tx_buffer_tail == i) - ; // wait until space in buffer - // cli(); - tx_buffer[i] = c; - tx_buffer_head = i; - UCSRnB = (1 << RXENn) | (1 << TXENn) | (1 << RXCIEn) | (1 << UDRIEn); - // sei(); -} - -// Receive a byte -uint8_t uart_getchar(void) { - uint8_t c, i; - - while (rx_buffer_head == rx_buffer_tail) - ; // wait for character - i = rx_buffer_tail + 1; - if (i >= RX_BUFFER_SIZE) i = 0; - c = rx_buffer[i]; - rx_buffer_tail = i; - return c; -} - -// Return whether the number of bytes waiting in the receive buffer is nonzero. -// Call this before uart_getchar() to check if it will need -// to wait for a byte to arrive. -bool uart_available(void) { - uint8_t head, tail; - - head = rx_buffer_head; - tail = rx_buffer_tail; - if (head >= tail) return (head - tail) > 0; - return (RX_BUFFER_SIZE + head - tail) > 0; -} - -// Transmit Interrupt -ISR(USARTn_UDRE_vect) { - uint8_t i; - - if (tx_buffer_head == tx_buffer_tail) { - // buffer is empty, disable transmit interrupt - UCSRnB = (1 << RXENn) | (1 << TXENn) | (1 << RXCIEn); - } else { - i = tx_buffer_tail + 1; - if (i >= TX_BUFFER_SIZE) i = 0; - UDRn = tx_buffer[i]; - tx_buffer_tail = i; - } -} - -// Receive Interrupt -ISR(USARTn_RX_vect) { - uint8_t c, i; - - c = UDRn; - i = rx_buffer_head + 1; - if (i >= RX_BUFFER_SIZE) i = 0; - if (i != rx_buffer_tail) { - rx_buffer[i] = c; - rx_buffer_head = i; - } -} |