448 lines
13 KiB
C++
448 lines
13 KiB
C++
/*
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with this library; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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The latest version of this library can always be found at
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http://arduiniana.org.
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*/
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// When set, _DEBUG co-opts pins 11 and 13 for debugging with an
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// oscilloscope or logic analyzer. Beware: it also slightly modifies
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// the bit times, so don't rely on it too much at high baud rates
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#define _DEBUG 0
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#define _DEBUG_PIN1 11
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#define _DEBUG_PIN2 13
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#define MAX_SOFT_SERIAL_SPEED 115200
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#define MIN_SOFT_SERIAL_SPEED 300
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//
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// Includes
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//
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// #include <avr/pgmspace.h>
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#include <Arduino.h>
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#include <SoftwareSerial.h>
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#include "mik32_hal_irq.h"
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#include "mik32_hal_gpio.h"
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#include "mik32_hal_scr1_timer.h"
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//
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// Statics
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//
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SoftwareSerial *SoftwareSerial::active_object = 0;
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uint8_t SoftwareSerial::_receive_buffer[_SS_MAX_RX_BUFF];
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volatile uint8_t SoftwareSerial::_receive_buffer_tail = 0;
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volatile uint8_t SoftwareSerial::_receive_buffer_head = 0;
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//
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// Debugging
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//
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// This function generates a brief pulse
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// for debugging or measuring on an oscilloscope.
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// #if _DEBUG
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// inline void DebugPulse(uint8_t pin, uint8_t count)
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// {
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// volatile uint8_t *pport = portOutputRegister(digitalPinToPort(pin));
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// uint8_t val = *pport;
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// while (count--)
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// {
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// *pport = val | digitalPinToBitMask(pin);
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// *pport = val;
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// }
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// }
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// #else
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// inline void DebugPulse(uint8_t, uint8_t) {}
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// #endif
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//
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// Private methods
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//
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// get ticks from systick
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#define CURRENT_TICKS ((uint64_t)(SCR1_TIMER->MTIMEH)<<32 | SCR1_TIMER->MTIME)
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// function placed in ram. Should not call other function placed in flash
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void SoftwareSerial::tunedDelay(uint32_t delayTicks)
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{
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uint64_t startTicks = CURRENT_TICKS;
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while ((CURRENT_TICKS - startTicks) < delayTicks)
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;
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}
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// This function sets the current object as the "listening"
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// one and returns true if it replaces another
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bool SoftwareSerial::listen()
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{
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if (!_rx_delay_stopbit)
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return false;
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if (active_object != this)
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{
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if (active_object)
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active_object->stopListening();
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_buffer_overflow = false;
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_receive_buffer_head = _receive_buffer_tail = 0;
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active_object = this;
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setRxIntMsk(true);
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return true;
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}
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return false;
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}
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// Stop listening. Returns true if we were actually listening.
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bool SoftwareSerial::stopListening()
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{
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if (active_object == this)
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{
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setRxIntMsk(false);
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active_object = NULL;
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return true;
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}
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return false;
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}
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//
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// The receive routine called by the interrupt handler
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//
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void SoftwareSerial::recv()
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{
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// if (active_object)
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// {
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// uint8_t data = 0;
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// // If RX line is high, then we don't see any start bit
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// // so interrupt is probably not for us
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// if (_inverse_logic ? rx_pin_read() : !rx_pin_read())
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// {
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// // Disable further interrupts during reception, this prevents
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// // triggering another interrupt directly after we return, which can
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// // cause problems at higher baudrates.
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// setRxIntMsk(false);
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// // Wait approximately 1/2 of a bit width to "center" the sample
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// tunedDelay(_rx_delay_centering);
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// // DebugPulse(_DEBUG_PIN2, 1);
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// // Read each of the 8 bits
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// for (uint8_t i=8; i > 0; --i)
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// {
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// tunedDelay(_rx_delay_intrabit);
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// data >>= 1;
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// // DebugPulse(_DEBUG_PIN2, 1);
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// if (rx_pin_read())
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// data |= 0x80;
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// }
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// if (_inverse_logic)
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// data = ~data;
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// // if buffer full, set the overflow flag and return
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// uint8_t next = (_receive_buffer_tail + 1) % _SS_MAX_RX_BUFF;
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// if (next != _receive_buffer_head)
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// {
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// // save new data in buffer: tail points to where byte goes
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// _receive_buffer[_receive_buffer_tail] = data; // save new byte
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// _receive_buffer_tail = next;
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// }
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// else
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// {
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// // DebugPulse(_DEBUG_PIN1, 1);
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// _buffer_overflow = true;
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// }
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// // skip the stop bit
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// tunedDelay(_rx_delay_stopbit);
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// // DebugPulse(_DEBUG_PIN1, 1);
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// // Re-enable interrupts when we're sure to be inside the stop bit
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// setRxIntMsk(true);
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// }
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// }
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}
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uint8_t SoftwareSerial::rx_pin_read()
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{
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return (uint8_t)HAL_GPIO_ReadPin((GPIO_TypeDef *)_receivePortRegister, (HAL_PinsTypeDef)_receiveBitMask);
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}
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//
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// Interrupt handling
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//
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/* static */
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inline void SoftwareSerial::handle_interrupt() // todo унести в обработчик прерываний
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{
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if (active_object)
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{
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active_object->recv();
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}
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}
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// #if defined(PCINT0_vect)
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// ISR(PCINT0_vect)
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// {
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// SoftwareSerial::handle_interrupt();
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// }
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// #endif
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//
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// Constructor
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//
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SoftwareSerial::SoftwareSerial(uint8_t receivePin, uint8_t transmitPin, bool inverse_logic /* = false */) :
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_rx_delay_centering(0),
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_rx_delay_intrabit(0),
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_rx_delay_stopbit(0),
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_tx_delay(0),
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_buffer_overflow(false),
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_inverse_logic(inverse_logic)
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{
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_transmitPin = transmitPin;
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_receivePin = receivePin;
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}
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//
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// Destructor
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//
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SoftwareSerial::~SoftwareSerial()
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{
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end();
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}
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void SoftwareSerial::setTX(uint8_t tx)
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{
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// First configure then write because writing pin didn't work until config is applied
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pinMode(tx, OUTPUT);
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digitalWrite(tx, _inverse_logic ? LOW : HIGH);
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_transmitBitMask = (uint16_t)digitalPinToBitMask(tx); // save tx bit mask
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_transmitPortRegister = (uint32_t)digitalPinToPort(tx); // save tx port adress
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}
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void SoftwareSerial::setRX(uint8_t rx)
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{
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_receiveBitMask = (uint16_t)digitalPinToBitMask(rx); // save rx bit mask
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_receivePortRegister = (uint32_t)digitalPinToPort(rx); // save rx port adress
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// attachInterrupt(digitalPinToInterrupt(rx), [this]() { this->recv(); }, _inverse_logic ? RISING : FALLING);
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if (!_inverse_logic)
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pinMode(rx, INPUT_PULLUP); // pullup for normal logic
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// HAL_GPIO_PinConfig((GPIO_TypeDef*)_receivePortRegister, (HAL_PinsTypeDef)_receiveBitMask, HAL_GPIO_MODE_GPIO_INPUT, HAL_GPIO_PULL_UP, HAL_GPIO_DS_2MA);
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else
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pinMode(rx, INPUT);
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}
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uint32_t SoftwareSerial::subtract_cap(uint32_t num, uint16_t sub)
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{
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if (num > sub)
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return num - sub;
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else
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return 1;
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}
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//
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// Public methods
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//
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void SoftwareSerial::begin(long speed)
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{
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// set pins config
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setRX(_receivePin);
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setTX(_transmitPin);
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_rx_delay_centering = _rx_delay_intrabit = _rx_delay_stopbit = _tx_delay = 0;
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// limit speed
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if (speed > MAX_SOFT_SERIAL_SPEED) speed = MAX_SOFT_SERIAL_SPEED;
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if (speed < MIN_SOFT_SERIAL_SPEED) speed = MIN_SOFT_SERIAL_SPEED;
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// Precalculate the various delays in number of ticks
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uint32_t bit_delay = F_CPU / speed;
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// 12 (gcc 4.8.2) or 13 (gcc 4.3.2) cycles from start bit to first bit,
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// 15 (gcc 4.8.2) or 16 (gcc 4.3.2) cycles between bits,
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// 12 (gcc 4.8.2) or 14 (gcc 4.3.2) cycles from last bit to stop bit
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// These are all close enough to just use 15 cycles, since the inter-bit
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// timings are the most critical (deviations stack 8 times)
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_tx_delay = subtract_cap(bit_delay, 35); // 15
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// Only setup rx when we have a valid INT for this pin
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if (digitalPinToInterrupt(_receivePin) != NOT_AN_INTERRUPT)
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{
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// #if GCC_VERSION > 40800
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// // Timings counted from gcc 4.8.2 output. This works up to 115200 on
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// // 16Mhz and 57600 on 8Mhz.
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// //
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// // When the start bit occurs, there are 3 or 4 cycles before the
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// // interrupt flag is set, 4 cycles before the PC is set to the right
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// // interrupt vector address and the old PC is pushed on the stack,
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// // and then 75 cycles of instructions (including the RJMP in the
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// // ISR vector table) until the first delay. After the delay, there
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// // are 17 more cycles until the pin value is read (excluding the
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// // delay in the loop).
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// // We want to have a total delay of 1.5 bit time. Inside the loop,
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// // we already wait for 1 bit time - 23 cycles, so here we wait for
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// // 0.5 bit time - (71 + 18 - 22) cycles.
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// _rx_delay_centering = subtract_cap(bit_delay / 2, (4 + 4 + 75 + 17 - 23));
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// // There are 23 cycles in each loop iteration (excluding the delay)
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// _rx_delay_intrabit = subtract_cap(bit_delay, 23);
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// // There are 37 cycles from the last bit read to the start of
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// // stopbit delay and 11 cycles from the delay until the interrupt
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// // mask is enabled again (which _must_ happen during the stopbit).
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// // This delay aims at 3/4 of a bit time, meaning the end of the
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// // delay will be at 1/4th of the stopbit. This allows some extra
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// // time for ISR cleanup, which makes 115200 baud at 16Mhz work more
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// // reliably
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// _rx_delay_stopbit = subtract_cap(bit_delay * 3 / 4, (37 + 11));
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// #else // Timings counted from gcc 4.3.2 output
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// // Note that this code is a _lot_ slower, mostly due to bad register
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// // allocation choices of gcc. This works up to 57600 on 16Mhz and
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// // 38400 on 8Mhz.
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// _rx_delay_centering = subtract_cap(bit_delay / 2, (4 + 4 + 97 + 29 - 11));
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// _rx_delay_intrabit = subtract_cap(bit_delay, 11);
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// _rx_delay_stopbit = subtract_cap(bit_delay * 3 / 4, (44 + 17));
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// #endif
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// Enable the INT for the entire port here, but never disable it
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// (others might also need it, so we disable the interrupt by using
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// the per-pin PCMSK register).
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// if (_inverse_logic)
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// _int_mode = GPIO_INT_MODE_RISING; // start bit: low to high
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// else
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// _int_mode = GPIO_INT_MODE_FALLING; // start bit: high to low
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// // Save gpio_mux and gpio_line for on/off interrupts
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// _int_maskMux = digitalPinToGpioIntMux(_receivePin); // gpio mux value
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// _int_maskLine = digitalPinToGpioIntLine(_receivePin); // gpio irq line value
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// HAL_EPIC_MaskEdgeSet(HAL_EPIC_GPIO_IRQ_MASK); // turn on the mask in EPIC
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// *digitalPinToPCICR((int8_t)_receivePin) |= _BV(digitalPinToPCICRbit(_receivePin));
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// _pcint_maskreg = digitalPinToPCMSK(_receivePin);
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// _pcint_maskvalue = _BV(digitalPinToPCMSKbit(_receivePin));
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}
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else
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ErrorMsgHandler("SoftwareSerial.begin(): Rx pin does not support interrupts, use different pin");
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tunedDelay(_tx_delay); // if we were low this establishes the end
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// #if _DEBUG
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// pinMode(_DEBUG_PIN1, OUTPUT);
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// pinMode(_DEBUG_PIN2, OUTPUT);
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// #endif
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listen();
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}
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void SoftwareSerial::setRxIntMsk(bool enable)
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{
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if (enable)
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HAL_GPIO_InitInterruptLine((HAL_GPIO_Line_Config)_int_maskMux, (HAL_GPIO_InterruptMode)_int_mode);
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// *_pcint_maskreg |= _pcint_maskvalue;
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else
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HAL_GPIO_DeInitInterruptLine((HAL_GPIO_Line)_int_maskLine);
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// *_pcint_maskreg &= ~_pcint_maskvalue;
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}
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void SoftwareSerial::end()
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{
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stopListening();
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}
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// function placed in ram. Should not call other function placed in flash
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size_t SoftwareSerial::write(uint8_t byte)
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{
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if (_tx_delay == 0)
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return 0;
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if (_inverse_logic)
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byte = ~byte;
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clear_csr(mie, MIE_MEIE); // turn off interrupts for a clean txmit
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// Write the start bit
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if (_inverse_logic)
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((GPIO_TypeDef *)_transmitPortRegister)->SET = (HAL_PinsTypeDef)_transmitBitMask;
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else
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((GPIO_TypeDef *)_transmitPortRegister)->CLEAR = (HAL_PinsTypeDef)_transmitBitMask;
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tunedDelay(_tx_delay); // wait start bit
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// Write each of the 8 bits in LSB mode
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for (uint8_t i = 8; i > 0; --i)
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{
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if (byte & 1) // choose bit
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((GPIO_TypeDef *)_transmitPortRegister)->SET = (HAL_PinsTypeDef)_transmitBitMask;
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else
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((GPIO_TypeDef *)_transmitPortRegister)->CLEAR = (HAL_PinsTypeDef)_transmitBitMask;
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tunedDelay(_tx_delay);
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byte >>= 1;
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}
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// restore pin to natural state - stop bit
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if (_inverse_logic)
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((GPIO_TypeDef *)_transmitPortRegister)->CLEAR = (HAL_PinsTypeDef)_transmitBitMask;
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else
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((GPIO_TypeDef *)_transmitPortRegister)->SET = (HAL_PinsTypeDef)_transmitBitMask;
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// enable interrupts
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set_csr(mstatus, MSTATUS_MIE);
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set_csr(mie, MIE_MEIE);
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tunedDelay(_tx_delay); // wait stop bit
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return 1;
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}
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// Read data from buffer
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int SoftwareSerial::read()
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{
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if (!isListening())
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return -1;
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// Empty buffer?
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if (_receive_buffer_head == _receive_buffer_tail)
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return -1;
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// Read from "head"
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uint8_t data = _receive_buffer[_receive_buffer_head]; // grab next byte
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_receive_buffer_head = (_receive_buffer_head + 1) % _SS_MAX_RX_BUFF;
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return data;
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}
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int SoftwareSerial::available()
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{
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if (!isListening())
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return 0;
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return ((unsigned int)(_receive_buffer_tail + _SS_MAX_RX_BUFF - _receive_buffer_head)) % _SS_MAX_RX_BUFF;
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}
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void SoftwareSerial::flush()
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{
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// There is no tx buffering, simply return
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}
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int SoftwareSerial::peek()
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{
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if (!isListening())
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return -1;
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// Empty buffer?
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if (_receive_buffer_head == _receive_buffer_tail)
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return -1;
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// Read from "head"
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return _receive_buffer[_receive_buffer_head];
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}
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