2015-06-23 12:42:35 -07:00

149 lines
3.4 KiB
C

/*
wiring_digital.c - digital input and output functions
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: wiring.c 248 2007-02-03 15:36:30Z mellis $
Modified 28-08-2009 for attiny84 R.Wiersma
Modified 14-10-2009 for attiny45 Saposoft
*/
#include "wiring_private.h"
#include "pins_arduino.h"
#include "core_pins.h"
#include "core_timers.h"
#include "PwmTimer.h"
void pinMode(uint8_t pin, uint8_t mode)
{
uint8_t bit = digitalPinToBitMask(pin);
uint8_t port = digitalPinToPort(pin);
volatile uint8_t *reg;
if (port == NOT_A_PIN) return;
// JWS: can I let the optimizer do this?
reg = portModeRegister(port);
if (mode == INPUT) {
uint8_t oldSREG = SREG;
cli();
*reg &= ~bit;
SREG = oldSREG;
} else {
uint8_t oldSREG = SREG;
cli();
*reg |= bit;
SREG = oldSREG;
}
}
// Forcing this inline keeps the callers from having to push their own stuff
// on the stack. It is a good performance win and only takes 1 more byte per
// user than calling. (It will take more bytes on the 168.)
//
// But shouldn't this be moved into pinMode? Seems silly to check and do on
// each digitalread or write.
//
__attribute__((always_inline)) static inline void turnOffPWM( uint8_t pin )
{
#if CORE_PWM_COUNT >= 1
if ( pin == CORE_PWM0_PIN )
{
Pwm0_SetCompareOutputMode( Pwm0_Disconnected );
}
else
#endif
#if CORE_PWM_COUNT >= 2
if ( pin == CORE_PWM1_PIN )
{
Pwm1_SetCompareOutputMode( Pwm1_Disconnected );
}
else
#endif
#if CORE_PWM_COUNT >= 3
if ( pin == CORE_PWM2_PIN )
{
Pwm2_SetCompareOutputMode( Pwm2_Disconnected );
}
else
#endif
#if CORE_PWM_COUNT >= 4
if ( pin == CORE_PWM3_PIN )
{
Pwm3_SetCompareOutputMode( Pwm3_Disconnected );
}
else
#endif
#if CORE_PWM_COUNT >= 5
#error Only 4 PWM pins are supported. Add more conditions.
#endif
{
}
}
void digitalWrite(uint8_t pin, uint8_t val)
{
uint8_t bit = digitalPinToBitMask(pin);
uint8_t port = digitalPinToPort(pin);
volatile uint8_t *out;
if (port == NOT_A_PIN) return;
// If the pin that support PWM output, we need to turn it off
// before doing a digital write.
turnOffPWM( pin );
out = portOutputRegister(port);
if (val == LOW) {
uint8_t oldSREG = SREG;
cli();
*out &= ~bit;
SREG = oldSREG;
} else {
uint8_t oldSREG = SREG;
cli();
*out |= bit;
SREG = oldSREG;
}
}
int digitalRead(uint8_t pin)
{
uint8_t bit = digitalPinToBitMask(pin);
uint8_t port = digitalPinToPort(pin);
if (port == NOT_A_PIN) return LOW;
// If the pin that support PWM output, we need to turn it off
// before getting a digital reading.
turnOffPWM( pin );
if (*portInputRegister(port) & bit) return HIGH;
return LOW;
}