| /* |
| 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 |
| |
| Modified 28 September 2010 by Mark Sproul |
| |
| $Id: wiring.c 248 2007-02-03 15:36:30Z mellis $ |
| */ |
| |
| #include "wiring_private.h" |
| #include "pins_arduino.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. |
| // |
| // Mark Sproul: |
| // - Removed inline. Save 170 bytes on atmega1280 |
| // - changed to a switch statment; added 32 bytes but much easier to read and maintain. |
| // - Added more #ifdefs, now compiles for atmega645 |
| // |
| //static inline void turnOffPWM(uint8_t timer) __attribute__ ((always_inline)); |
| //static inline void turnOffPWM(uint8_t timer) |
| static void turnOffPWM(uint8_t timer) |
| { |
| switch (timer) |
| { |
| #if defined(TCCR1A) && defined(COM1A1) |
| case TIMER1A: cbi(TCCR1A, COM1A1); break; |
| #endif |
| #if defined(TCCR1A) && defined(COM1B1) |
| case TIMER1B: cbi(TCCR1A, COM1B1); break; |
| #endif |
| |
| #if defined(TCCR2) && defined(COM21) |
| case TIMER2: cbi(TCCR2, COM21); break; |
| #endif |
| |
| #if defined(TCCR0A) && defined(COM0A1) |
| case TIMER0A: cbi(TCCR0A, COM0A1); break; |
| #endif |
| |
| #if defined(TIMER0B) && defined(COM0B1) |
| case TIMER0B: cbi(TCCR0A, COM0B1); break; |
| #endif |
| #if defined(TCCR2A) && defined(COM2A1) |
| case TIMER2A: cbi(TCCR2A, COM2A1); break; |
| #endif |
| #if defined(TCCR2A) && defined(COM2B1) |
| case TIMER2B: cbi(TCCR2A, COM2B1); break; |
| #endif |
| |
| #if defined(TCCR3A) && defined(COM3A1) |
| case TIMER3A: cbi(TCCR3A, COM3A1); break; |
| #endif |
| #if defined(TCCR3A) && defined(COM3B1) |
| case TIMER3B: cbi(TCCR3A, COM3B1); break; |
| #endif |
| #if defined(TCCR3A) && defined(COM3C1) |
| case TIMER3C: cbi(TCCR3A, COM3C1); break; |
| #endif |
| |
| #if defined(TCCR4A) && defined(COM4A1) |
| case TIMER4A: cbi(TCCR4A, COM4A1); break; |
| #endif |
| #if defined(TCCR4A) && defined(COM4B1) |
| case TIMER4B: cbi(TCCR4A, COM4B1); break; |
| #endif |
| #if defined(TCCR4A) && defined(COM4C1) |
| case TIMER4C: cbi(TCCR4A, COM4C1); break; |
| #endif |
| #if defined(TCCR5A) |
| case TIMER5A: cbi(TCCR5A, COM5A1); break; |
| case TIMER5B: cbi(TCCR5A, COM5B1); break; |
| case TIMER5C: cbi(TCCR5A, COM5C1); break; |
| #endif |
| } |
| } |
| |
| void digitalWrite(uint8_t pin, uint8_t val) |
| { |
| uint8_t timer = digitalPinToTimer(pin); |
| 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. |
| if (timer != NOT_ON_TIMER) turnOffPWM(timer); |
| |
| 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 timer = digitalPinToTimer(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. |
| if (timer != NOT_ON_TIMER) turnOffPWM(timer); |
| |
| if (*portInputRegister(port) & bit) return HIGH; |
| return LOW; |
| } |