Files
Marlin/Marlin/src/HAL/HAL_LPC1768/SoftwareSerial.cpp
Christopher Pepper b908e38d08 Add needed platform defined gaurds to compile with Arduino IDE
Also removed explicit platform HAL directory inclusion from platformio.ini to make sure these errors are caught by Travis in the future
2017-08-31 18:33:07 -05:00

402 lines
9.7 KiB
C++

/*
SoftwareSerial.cpp (formerly NewSoftSerial.cpp) -
Multi-instance software serial library for Arduino/Wiring
-- Interrupt-driven receive and other improvements by ladyada
(http://ladyada.net)
-- Tuning, circular buffer, derivation from class Print/Stream,
multi-instance support, porting to 8MHz processors,
various optimizations, PROGMEM delay tables, inverse logic and
direct port writing by Mikal Hart (http://www.arduiniana.org)
-- Pin change interrupt macros by Paul Stoffregen (http://www.pjrc.com)
-- 20MHz processor support by Garrett Mace (http://www.macetech.com)
-- ATmega1280/2560 support by Brett Hagman (http://www.roguerobotics.com/)
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
The latest version of this library can always be found at
http://arduiniana.org.
*/
#ifdef TARGET_LPC1768
//
// Includes
//
//#include <WInterrupts.h>
#include "../../../macros.h"
#include "../HAL.h"
#include <stdint.h>
#include <stdarg.h>
#include "arduino.h"
#include "pinmapping.h"
#include "pinmap_re_arm.h"
#include "fastio.h"
#include "SoftwareSerial.h"
void GpioEnableInt(uint32_t port, uint32_t pin, uint32_t mode);
void GpioDisableInt(uint32_t port, uint32_t pin);
//
// Statics
//
SoftwareSerial *SoftwareSerial::active_object = 0;
unsigned char SoftwareSerial::_receive_buffer[_SS_MAX_RX_BUFF];
volatile uint8_t SoftwareSerial::_receive_buffer_tail = 0;
volatile uint8_t SoftwareSerial::_receive_buffer_head = 0;
typedef struct _DELAY_TABLE
{
long baud;
uint16_t rx_delay_centering;
uint16_t rx_delay_intrabit;
uint16_t rx_delay_stopbit;
uint16_t tx_delay;
} DELAY_TABLE;
// rough delay estimation
static const DELAY_TABLE table[] =
{
//baud |rxcenter|rxintra |rxstop |tx
{ 250000, 2, 4, 4, 4, }, //Done but not good due to instruction cycle error
{ 115200, 4, 8, 8, 8, }, //Done but not good due to instruction cycle error
//{ 74880, 69, 139, 62, 162, }, // estimation
// { 57600, 100, 185, 1, 208, }, // Done but not good due to instruction cycle error
//{ 38400, 13, 26, 26, 26, }, // Done
//{ 19200, 26, 52, 52, 52, }, // Done
{ 9600, 52, 104, 104, 104, }, // Done
//{ 4800, 104, 208, 208, 208, },
//{ 2400, 208, 417, 417, 417, },
//{ 1200, 416, 833, 833, 833,},
};
//
// Private methods
//
#if 0
/* static */
inline void SoftwareSerial::tunedDelay(uint32_t count) {
asm volatile(
"mov r3, %[loopsPerMicrosecond] \n\t" //load the initial loop counter
"1: \n\t"
"sub r3, r3, #1 \n\t"
"bne 1b \n\t"
://empty output list
:[loopsPerMicrosecond] "r" (count)
:"r3", "cc" //clobber list
);
}
#else
inline void SoftwareSerial::tunedDelay(uint32_t count) {
delayMicroseconds(count);
}
#endif
// This function sets the current object as the "listening"
// one and returns true if it replaces another
bool SoftwareSerial::listen()
{
if (!_rx_delay_stopbit)
return false;
if (active_object != this)
{
if (active_object)
active_object->stopListening();
_buffer_overflow = false;
_receive_buffer_head = _receive_buffer_tail = 0;
active_object = this;
setRxIntMsk(true);
return true;
}
return false;
}
// Stop listening. Returns true if we were actually listening.
bool SoftwareSerial::stopListening()
{
if (active_object == this)
{
setRxIntMsk(false);
active_object = NULL;
return true;
}
return false;
}
//
// The receive routine called by the interrupt handler
//
void SoftwareSerial::recv()
{
uint8_t d = 0;
// If RX line is high, then we don't see any start bit
// so interrupt is probably not for us
if (_inverse_logic ? rx_pin_read() : !rx_pin_read())
{
// Disable further interrupts during reception, this prevents
// triggering another interrupt directly after we return, which can
// cause problems at higher baudrates.
setRxIntMsk(false);//__disable_irq();//
// Wait approximately 1/2 of a bit width to "center" the sample
tunedDelay(_rx_delay_centering);
// Read each of the 8 bits
for (uint8_t i=8; i > 0; --i)
{
tunedDelay(_rx_delay_intrabit);
d >>= 1;
if (rx_pin_read())
d |= 0x80;
}
if (_inverse_logic)
d = ~d;
// if buffer full, set the overflow flag and return
uint8_t next = (_receive_buffer_tail + 1) % _SS_MAX_RX_BUFF;
if (next != _receive_buffer_head)
{
// save new data in buffer: tail points to where byte goes
_receive_buffer[_receive_buffer_tail] = d; // save new byte
_receive_buffer_tail = next;
}
else
{
_buffer_overflow = true;
}
tunedDelay(_rx_delay_stopbit);
// Re-enable interrupts when we're sure to be inside the stop bit
setRxIntMsk(true);//__enable_irq();//
}
}
uint32_t SoftwareSerial::rx_pin_read()
{
return digitalRead(_receivePin);
}
//
// Interrupt handling
//
/* static */
inline void SoftwareSerial::handle_interrupt()
{
if (active_object)
{
active_object->recv();
}
}
extern "C" void intWrapper() {
SoftwareSerial::handle_interrupt();
}
//
// Constructor
//
SoftwareSerial::SoftwareSerial(uint8_t receivePin, uint8_t transmitPin, bool inverse_logic /* = false */) :
_rx_delay_centering(0),
_rx_delay_intrabit(0),
_rx_delay_stopbit(0),
_tx_delay(0),
_buffer_overflow(false),
_inverse_logic(inverse_logic)
{
setTX(transmitPin);
setRX(receivePin);
}
//
// Destructor
//
SoftwareSerial::~SoftwareSerial()
{
end();
}
void SoftwareSerial::setTX(uint8_t tx)
{
// First write, then set output. If we do this the other way around,
// the pin would be output low for a short while before switching to
// output hihg. Now, it is input with pullup for a short while, which
// is fine. With inverse logic, either order is fine.
digitalWrite(tx, _inverse_logic ? LOW : HIGH);
pinMode(tx,OUTPUT);
_transmitPin = tx;
}
void SoftwareSerial::setRX(uint8_t rx)
{
pinMode(rx, INPUT_PULLUP); // pullup for normal logic!
//if (!_inverse_logic)
// digitalWrite(rx, HIGH);
_receivePin = rx;
_receivePort = pin_map[rx].port;
_receivePortPin = pin_map[rx].pin;
/* GPIO_T * rxPort = digitalPinToPort(rx);
_receivePortRegister = portInputRegister(rxPort);
_receiveBitMask = digitalPinToBitMask(rx);*/
}
//
// Public methods
//
void SoftwareSerial::begin(long speed)
{
_rx_delay_centering = _rx_delay_intrabit = _rx_delay_stopbit = _tx_delay = 0;
for(uint8_t i = 0; i < sizeof(table)/sizeof(table[0]); ++i)
{
long baud = table[i].baud;
if(baud == speed)
{
_rx_delay_centering = table[i].rx_delay_centering;
_rx_delay_intrabit = table[i].rx_delay_intrabit;
_rx_delay_stopbit = table[i].rx_delay_stopbit;
_tx_delay = table[i].tx_delay;
break;
}
}
attachInterrupt(_receivePin, intWrapper, CHANGE); //this->handle_interrupt, CHANGE);
listen();
tunedDelay(_tx_delay);
}
void SoftwareSerial::setRxIntMsk(bool enable)
{
if (enable)
GpioEnableInt(_receivePort,_receivePin,CHANGE);
else
GpioDisableInt(_receivePort,_receivePin);
}
void SoftwareSerial::end()
{
stopListening();
}
// Read data from buffer
int SoftwareSerial::read()
{
if (!isListening())
return -1;
// Empty buffer?
if (_receive_buffer_head == _receive_buffer_tail)
return -1;
// Read from "head"
uint8_t d = _receive_buffer[_receive_buffer_head]; // grab next byte
_receive_buffer_head = (_receive_buffer_head + 1) % _SS_MAX_RX_BUFF;
return d;
}
int SoftwareSerial::available()
{
if (!isListening())
return 0;
return (_receive_buffer_tail + _SS_MAX_RX_BUFF - _receive_buffer_head) % _SS_MAX_RX_BUFF;
}
size_t SoftwareSerial::write(uint8_t b)
{
// By declaring these as local variables, the compiler will put them
// in registers _before_ disabling interrupts and entering the
// critical timing sections below, which makes it a lot easier to
// verify the cycle timings
bool inv = _inverse_logic;
uint16_t delay = _tx_delay;
if(inv)
b = ~b;
cli(); // turn off interrupts for a clean txmit
// Write the start bit
if (inv)
digitalWrite(_transmitPin, 1);
else
digitalWrite(_transmitPin, 0);
tunedDelay(delay);
// Write each of the 8 bits
for (uint8_t i = 8; i > 0; --i)
{
if (b & 1) // choose bit
digitalWrite(_transmitPin, 1); // send 1 //(GPIO_Desc[_transmitPin].P)->DOUT |= GPIO_Desc[_transmitPin].bit;
else
digitalWrite(_transmitPin, 0); // send 0 //(GPIO_Desc[_transmitPin].P)->DOUT &= ~GPIO_Desc[_transmitPin].bit;
tunedDelay(delay);
b >>= 1;
}
// restore pin to natural state
if (inv)
digitalWrite(_transmitPin, 0);
else
digitalWrite(_transmitPin, 1);
sei(); // turn interrupts back on
tunedDelay(delay);
return 1;
}
void SoftwareSerial::flush()
{
if (!isListening())
return;
cli();
_receive_buffer_head = _receive_buffer_tail = 0;
sei();
}
int SoftwareSerial::peek()
{
if (!isListening())
return -1;
// Empty buffer?
if (_receive_buffer_head == _receive_buffer_tail)
return -1;
// Read from "head"
return _receive_buffer[_receive_buffer_head];
}
#endif // TARGET_LPC1768