/* Copyright 2013 Jun WAKO <wakojun@gmail.com> This software is licensed with a Modified BSD License. All of this is supposed to be Free Software, Open Source, DFSG-free, GPL-compatible, and OK to use in both free and proprietary applications. Additions and corrections to this file are welcome. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of the copyright holders nor the names of contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include <stdbool.h> #include <avr/io.h> #include <avr/interrupt.h> #include "serial.h" #if defined(SERIAL_UART_RTS_LO) && defined(SERIAL_UART_RTS_HI) // Buffer state // Empty: RBUF_SPACE == RBUF_SIZE(head==tail) // Last 1 space: RBUF_SPACE == 2 // Full: RBUF_SPACE == 1(last cell of rbuf be never used.) #define RBUF_SPACE() (rbuf_head < rbuf_tail ? (rbuf_tail - rbuf_head) : (RBUF_SIZE - rbuf_head + rbuf_tail)) // allow to send #define rbuf_check_rts_lo() do { if (RBUF_SPACE() > 2) SERIAL_UART_RTS_LO(); } while (0) // prohibit to send #define rbuf_check_rts_hi() do { if (RBUF_SPACE() <= 2) SERIAL_UART_RTS_HI(); } while (0) #else #define rbuf_check_rts_lo() #define rbuf_check_rts_hi() #endif void serial_init(void) { SERIAL_UART_INIT(); } // RX ring buffer #define RBUF_SIZE 256 static uint8_t rbuf[RBUF_SIZE]; static uint8_t rbuf_head = 0; static uint8_t rbuf_tail = 0; uint8_t serial_recv(void) { uint8_t data = 0; if (rbuf_head == rbuf_tail) { return 0; } data = rbuf[rbuf_tail]; rbuf_tail = (rbuf_tail + 1) % RBUF_SIZE; rbuf_check_rts_lo(); return data; } int16_t serial_recv2(void) { uint8_t data = 0; if (rbuf_head == rbuf_tail) { return -1; } data = rbuf[rbuf_tail]; rbuf_tail = (rbuf_tail + 1) % RBUF_SIZE; rbuf_check_rts_lo(); return data; } void serial_send(uint8_t data) { while (!SERIAL_UART_TXD_READY) ; SERIAL_UART_DATA = data; } // USART RX complete interrupt ISR(SERIAL_UART_RXD_VECT) { uint8_t next = (rbuf_head + 1) % RBUF_SIZE; if (next != rbuf_tail) { rbuf[rbuf_head] = SERIAL_UART_DATA; rbuf_head = next; } rbuf_check_rts_hi(); }