mirror of
https://github.com/qmk/qmk_firmware.git
synced 2024-12-14 22:00:53 +00:00
134 lines
4.2 KiB
C
134 lines
4.2 KiB
C
/*
|
|
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"
|
|
|
|
#ifndef SERIAL_UART_BAUD
|
|
# define SERIAL_UART_BAUD 9600
|
|
#endif
|
|
|
|
#define SERIAL_UART_UBRR (F_CPU / (16UL * SERIAL_UART_BAUD) - 1)
|
|
#define SERIAL_UART_TXD_READY (UCSR1A & _BV(UDRE1))
|
|
#define SERIAL_UART_RXD_VECT USART1_RX_vect
|
|
|
|
#ifndef SERIAL_UART_INIT_CUSTOM
|
|
# define SERIAL_UART_INIT_CUSTOM \
|
|
/* enable TX */ \
|
|
UCSR1B = _BV(TXEN1); \
|
|
/* 8-bit data */ \
|
|
UCSR1C = _BV(UCSZ11) | _BV(UCSZ10);
|
|
#endif
|
|
|
|
#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) {
|
|
do {
|
|
// Set baud rate
|
|
UBRR1L = SERIAL_UART_UBRR;
|
|
UBRR1L = SERIAL_UART_UBRR >> 8;
|
|
SERIAL_UART_INIT_CUSTOM;
|
|
} while (0);
|
|
}
|
|
|
|
// 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();
|
|
}
|