/* uart.avr.c */ /* avr.uart - UART AVR module. {{{ * * Copyright (C) 2005 Nicolas Schodet * * Robot APB Team/Efrei 2006. * Web: http://assos.efrei.fr/robot/ * Email: robot AT efrei DOT fr * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * }}} */ #include "common.h" #include "uart.h" #include "uart_common.h" #if AC_UART (PORT) != -1 #include "io.h" /* Tested AVR check. */ #if defined (__AVR_ATmega8__) #elif defined (__AVR_ATmega8535__) #elif defined (__AVR_ATmega16__) #elif defined (__AVR_ATmega32__) #elif defined (__AVR_ATmega128__) # define PE UPE #elif defined (__AVR_ATmega64__) # define PE UPE #else # warning "uart: not tested on this chip" #endif /* UART port number. */ #if AC_UART (PORT) == 0 # if !defined (UBRRH) # if defined (UBRR0H) # define UBRRH UBRR0H # define UBRRL UBRR0L # define UCSRA UCSR0A # define UCSRB UCSR0B # define UCSRC UCSR0C # define UDR UDR0 # define SIG_UART_RECV SIG_UART0_RECV # define SIG_UART_DATA SIG_UART0_DATA # else # error "uart: can not find uart 0" # endif /* defined (UBRR0H) */ # endif /* !defined (UBRRH) */ #else /* AC_UART (PORT) == 1 */ # if defined (UBRR1H) # define UBRRH UBRR1H # define UBRRL UBRR1L # define UCSRA UCSR1A # define UCSRB UCSR1B # define UCSRC UCSR1C # define UDR UDR1 # define SIG_UART_RECV SIG_UART1_RECV # define SIG_UART_DATA SIG_UART1_DATA # else # error "uart: can not find uart 1" # endif /* defined (UBRR1H) */ #endif /* AC_UART (PORT) == 1 */ /* UR selector (UCSRC & UBRRH multiplexed). */ #if defined (URSEL) # define SELECTOR _BV (URSEL) #else # define SELECTOR 0 #endif /* Baud rate error check. */ #define UBRR_VAL (AC_FREQ / 16 / AC_UART (BAUDRATE) - 1) #define BAUDRATE_VAL (AC_FREQ / 16 / (UBRR_VAL + 1)) #if BAUDRATE_VAL - AC_UART (BAUDRATE) > 2 #warning "uart: baud rate error > 2" #elif BAUDRATE_VAL - AC_UART (BAUDRATE) > 1 #warning "uart: baud rate error > 1" #elif BAUDRATE_VAL - AC_UART (BAUDRATE) > 0 #warning "uart: baud rate error > 0" #endif /* Mode. */ #define POLLING 1 #define RING 2 #define SEND_MODE AC_UART (SEND_MODE) #define RECV_MODE AC_UART (RECV_MODE) #if RECV_MODE == POLLING # define RECV_IE 0 #elif RECV_MODE == RING # define RECV_IE _BV (RXCIE) #else # error "uart: bad mode" #endif /* Parity. */ #define ODD (_BV (UPM1) | _BV (UPM0)) #define EVEN _BV (UPM1) #define NONE 0 #define PARITY AC_UART (PARITY) /* Stop bits. */ #if AC_UART (STOP_BITS) == 1 #define STOP_BITS 0 #elif AC_UART (STOP_BITS) == 2 #define STOP_BITS _BV (USBS) #else #error "uart: bad stop bits value" #endif /* Character size. */ #define CHAR_SIZE (_BV (UCSZ1) | _BV (UCSZ0)) /* Buffers. */ #if SEND_MODE == RING # define SEND_BUFFER_SIZE AC_UART (SEND_BUFFER_SIZE) # define SEND_BUFFER_MASK (SEND_BUFFER_SIZE - 1) # if SEND_BUFFER_SIZE & SEND_BUFFER_MASK # error "uart: send buffer size must be a power of 2" # endif #endif #if RECV_MODE == RING # define RECV_BUFFER_SIZE AC_UART (RECV_BUFFER_SIZE) # define RECV_BUFFER_MASK (RECV_BUFFER_SIZE - 1) # if RECV_BUFFER_SIZE & RECV_BUFFER_MASK # error "uart: recv buffer size must be a power of 2" # endif #endif /* Send buffer. */ #if SEND_MODE == RING static uint8_t uart_send_buffer[SEND_BUFFER_SIZE]; static volatile uint8_t uart_send_head, uart_send_tail; #endif /* Recv buffer. */ #if RECV_MODE == RING static uint8_t uart_recv_buffer[RECV_BUFFER_SIZE]; static volatile uint8_t uart_recv_head, uart_recv_tail; #endif /* Full buffer politic. */ #define DROP 1 #define WAIT 2 #define SEND_BUFFER_FULL AC_UART (SEND_BUFFER_FULL) #if SEND_BUFFER_FULL != DROP && SEND_BUFFER_FULL != WAIT # error "uart: bad full buffer politic" #endif /* Error code. */ #define ERROR_BITS (_BV (FE) | _BV (DOR) | _BV (PE)) /* +AutoDec */ /* -AutoDec */ /** Initialise uart. */ void uart_init (void) { /* Set baud rate. */ #if (UBRR_VAL >> 8) != 0 UBRRH = UBRR_VAL >> 8; #endif UBRRL = UBRR_VAL & 0xff; UCSRA = 0; /* Set format and enable uart. */ UCSRC = SELECTOR | PARITY | STOP_BITS | CHAR_SIZE; UCSRB = RECV_IE | _BV (RXEN) | _BV (TXEN); #if RECV_MODE == RING uart_recv_head = 0; uart_recv_tail = 0; #endif #if SEND_MODE == RING uart_send_head = 0; uart_send_tail = 0; #endif } /** Read a char. */ uint8_t uart_getc (void) { #if RECV_MODE == POLLING uint8_t tmperr, c; loop_until_bit_is_set (UCSRA, RXC); tmperr = UCSRA & ERROR_BITS; c = UDR; if (tmperr) return 0xff; else return c; #elif RECV_MODE == RING uint8_t tmptail = uart_recv_tail; while (uart_recv_head == tmptail) ; tmptail = (tmptail + 1) & RECV_BUFFER_MASK; uart_recv_tail = tmptail; return uart_recv_buffer[tmptail]; #endif } /** Write a char. */ void uart_putc (uint8_t c) { #if SEND_MODE == POLLING # if SEND_BUFFER_FULL == WAIT loop_until_bit_is_set (UCSRA, UDRE); # else if (!(UCSRA & _BV (UDRE))) return; # endif UDR = c; #elif SEND_MODE == RING uint8_t tmphead; tmphead = (uart_send_head + 1) & SEND_BUFFER_MASK; # if SEND_BUFFER_FULL == WAIT while (tmphead == uart_send_tail) ; # else if (tmphead == uart_send_tail) return; # endif uart_send_buffer[tmphead] = c; uart_send_head = tmphead; UCSRB |= _BV (UDRIE); #endif } /** Retrieve available chars. */ uint8_t uart_poll (void) { #if RECV_MODE == POLLING return UCSRA & _BV (RXC); #elif RECV_MODE == RING return (uart_recv_head - uart_recv_tail) & RECV_BUFFER_MASK; #endif } #if RECV_MODE == RING /* Handle received char for ring buffer. */ SIGNAL (SIG_UART_RECV) { uint8_t c; uint8_t tmphead; uint8_t tmperr; tmperr = UCSRA & ERROR_BITS; c = UDR; if (tmperr) c = 0xff; tmphead = (uart_recv_head + 1) & RECV_BUFFER_MASK; uart_recv_head = tmphead; /* If overflowed, clear the receive buffer. */ if (tmphead == uart_recv_tail) { tmphead = (tmphead + 1) & RECV_BUFFER_MASK; uart_recv_head = tmphead; c = 0xff; } uart_recv_buffer[tmphead] = c; } #endif /* RECV_MODE == RING */ #if SEND_MODE == RING /** Handle data register empty for ring buffer. */ SIGNAL (SIG_UART_DATA) { uint8_t tmptail; if (uart_send_head != uart_send_tail) { tmptail = (uart_send_tail + 1) & SEND_BUFFER_MASK; uart_send_tail = tmptail; UDR = uart_send_buffer[tmptail]; } else { UCSRB &= ~_BV (UDRIE); } } #endif /* SEND_MODE == RING */ #endif /* AC_UART (PORT) != -1 */