wiring.h

/*
  wiring.h - Partial implementation of the Wiring API for the ATmega8.
  Part of Arduino - http://www.arduino.cc/

  Copyright (c) 2005-2006 David A. Mellis

  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., 59 Temple Place, Suite 330,
  Boston, MA  02111-1307  USA

  $Id$
*/

#ifndef Wiring_h
#define Wiring_h

#include <avr/io.h>
#include <avr/interrupt.h>
#include <stdlib.h>
#include "binary.h"
#include "pins_arduino.h"

#ifdef __cplusplus
extern "C"{
#endif

#define HIGH 0x1
#define LOW  0x0

#define INPUT 0x0
#define OUTPUT 0x1

#define true 0x1
#define false 0x0

#define PI 3.1415926535897932384626433832795
#define HALF_PI 1.5707963267948966192313216916398
#define TWO_PI 6.283185307179586476925286766559
#define DEG_TO_RAD 0.017453292519943295769236907684886
#define RAD_TO_DEG 57.295779513082320876798154814105

#define SERIAL  0x0
#define DISPLAY 0x1

#define LSBFIRST 0
#define MSBFIRST 1

#define CHANGE 1
#define FALLING 2
#define RISING 3

#if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
#define INTERNAL1V1 2
#define INTERNAL2V56 3
#else
#define INTERNAL 3
#endif
#define DEFAULT 1
#define EXTERNAL 0

// undefine stdlib's abs if encountered
#ifdef abs
#undef abs
#endif

#define min(a,b) ((a)<(b)?(a):(b))
#define max(a,b) ((a)>(b)?(a):(b))
#define abs(x) ((x)>0?(x):-(x))
#define constrain(amt,low,high) ((amt)<(low)?(low):((amt)>(high)?(high):(amt)))
#define round(x)     ((x)>=0?(long)((x)+0.5):(long)((x)-0.5))
#define radians(deg) ((deg)*DEG_TO_RAD)
#define degrees(rad) ((rad)*RAD_TO_DEG)
#define sq(x) ((x)*(x))

#define interrupts() sei()
#define noInterrupts() cli()

#define clockCyclesPerMicrosecond() ( F_CPU / 1000000L )
#define clockCyclesToMicroseconds(a) ( ((a) * 1000L) / (F_CPU / 1000L) )
#define microsecondsToClockCycles(a) ( ((a) * (F_CPU / 1000L)) / 1000L )

#define lowByte(w) ((uint8_t) ((w) & 0xff))
#define highByte(w) ((uint8_t) ((w) >> 8))

#define bitRead(value, bit) (((value) >> (bit)) & 0x01)
#define bitSet(value, bit) ((value) |= (1UL << (bit)))
#define bitClear(value, bit) ((value) &= ~(1UL << (bit)))
#define bitWrite(value, bit, bitvalue) (bitvalue ? bitSet(value, bit) : bitClear(value, bit))


typedef unsigned int word;

#define bit(b) (1UL << (b))

typedef uint8_t boolean;
typedef uint8_t byte;

void init(void);

void pinMode_lookup(uint8_t, uint8_t);
void digitalWrite_lookup(uint8_t, uint8_t);
int digitalRead_lookup(uint8_t);
int analogRead(uint8_t);
void analogReference(uint8_t mode);
void analogWrite(uint8_t, int);

unsigned long millis(void);
unsigned long micros(void);
void delay(unsigned long);
void delayMicroseconds(unsigned int us);
unsigned long pulseIn(uint8_t pin, uint8_t state, unsigned long timeout);

void shiftOut(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder, uint8_t val);
uint8_t shiftIn(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder);

void attachInterrupt(uint8_t, void (*)(void), int mode);
void detachInterrupt(uint8_t);

void setup(void);
void loop(void);

INLINED uint8_t digitalPinToPort(uint8_t pin) {
	if (__builtin_constant_p(pin))
		return inlined_digitalPinToPort(pin);
	else
		return pgm_read_byte( digital_pin_to_port_PGM + pin );
}

INLINED uint8_t digitalPinToBitMask(uint8_t pin) {
	if (__builtin_constant_p(pin))
		return inlined_digitalPinToBitMask(pin);
	else
		return pgm_read_byte( digital_pin_to_bit_mask_PGM + pin );
}

INLINED uint8_t digitalPinToTimer(uint8_t pin) {
	if (__builtin_constant_p(pin))
		return inlined_digitalPinToTimer(pin);
	else
		return pgm_read_byte( digital_pin_to_timer_PGM + pin );
}

INLINED volatile uint8_t *portOutputRegister(uint8_t index) {
	if (__builtin_constant_p(index))
		return inlined_portOutputRegister(index);
	else
		return (volatile uint8_t *)( pgm_read_word( port_to_output_PGM + index ) );
}

INLINED volatile uint8_t* portInputRegister(uint8_t index) {
	if (__builtin_constant_p(index))
		return inlined_portInputRegister(index);
	else
		return (volatile uint8_t *)( pgm_read_word( port_to_input_PGM + index) );
}

INLINED volatile uint8_t* portModeRegister(uint8_t index) {
	if (__builtin_constant_p(index))
		return inlined_portModeRegister(index);
	else
		return (volatile uint8_t *)( pgm_read_word( port_to_mode_PGM + index) );
}

/*
 * Check if a given pin requires locking.
 * When accessing lower 32 IO ports we can use SBI/CBI instructions, which are atomic. However
 * other IO ports require load+modify+store and we need to make them atomic by disabling
 * interrupts.
 */
INLINED int registerWriteNeedsLocking(volatile uint8_t *reg)
{
	/* SBI/CBI instructions only work on lower 32 IO ports */
	if (reg > (volatile uint8_t*)&_SFR_IO8(0x1F)) {
		return 1;
	}
	return 0;
}

#define digitalWrite_implementation(pin, value)\
do {\
	uint8_t oldSREG;\
	uint8_t bit = digitalPinToBitMask(pin);\
	uint8_t port = digitalPinToPort(pin);\
	volatile uint8_t *reg = portOutputRegister(port);\
\
	if (!__builtin_constant_p(pin) || registerWriteNeedsLocking(reg)) {\
		oldSREG = SREG;\
		cli();\
	}\
\
	if (value == LOW) {\
		*reg &= ~bit;\
	} else {\
		*reg |= bit;\
	}\
\
	if (!__builtin_constant_p(pin) || registerWriteNeedsLocking(reg)) {\
		SREG = oldSREG;\
	}\
} while(0)
	
INLINED void digitalWrite(uint8_t pin, uint8_t value)
{
	if (__builtin_constant_p(pin)) digitalWrite_implementation(pin, value);
	else digitalWrite_lookup(pin, value);
}

#define pinMode_implementation(pin, value)\
do {\
	uint8_t bit = digitalPinToBitMask(pin);\
	uint8_t oldSREG;\
	uint8_t port = digitalPinToPort(pin);\
	volatile uint8_t *reg = portModeRegister(port);\
\
	if (!__builtin_constant_p(pin) || registerWriteNeedsLocking(reg)) {\
		oldSREG = SREG;\
		cli();\
	}\
\
	if (value == INPUT) { \
		*reg &= ~bit;\
	} else {\
		*reg |= bit;\
	}\
\
	if (!__builtin_constant_p(pin) || registerWriteNeedsLocking(reg)) {\
		SREG = oldSREG;\
	}\
} while(0)

INLINED void pinMode(uint8_t pin, uint8_t value)
{
	if (__builtin_constant_p(pin)) pinMode_implementation(pin, value);
	else pinMode_lookup(pin, value);
}

#define digitalRead_implementation(pin)\
do {\
	uint8_t bit = digitalPinToBitMask(pin);\
	uint8_t port = digitalPinToPort(pin);\
\
	if (port == NOT_A_PIN) return LOW;\
\
	if (*portInputRegister(port) & bit) return HIGH;\
	return LOW;\
} while(0)

INLINED int digitalRead(uint8_t pin)
{
	if (__builtin_constant_p(pin)) digitalRead_implementation(pin);
	else return digitalRead_lookup(pin);
}


#ifdef __cplusplus
} // extern "C"
#endif

#endif