1 /* 2 wiring_digital.c - digital input and output functions 3 Part of Arduino - http://www.arduino.cc/ 4 5 Copyright (c) 2005-2006 David A. Mellis 6 7 This library is free software; you can redistribute it and/or 8 modify it under the terms of the GNU Lesser General Public 9 License as published by the Free Software Foundation; either 10 version 2.1 of the License, or (at your option) any later version. 11 12 This library is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 Lesser General Public License for more details. 16 17 You should have received a copy of the GNU Lesser General 18 Public License along with this library; if not, write to the 19 Free Software Foundation, Inc., 59 Temple Place, Suite 330, 20 Boston, MA 02111-1307 USA 21 22 Modified 28 September 2010 by Mark Sproul 23 24 $Id: wiring.c 248 2007-02-03 15:36:30Z mellis $ 25 */ 26 27 #include "wiring_private.h" 28 #include "pins_arduino.h" 29 30 void pinMode(uint8_t pin, uint8_t mode) 31 { 32 uint8_t bit = digitalPinToBitMask(pin); 33 uint8_t port = digitalPinToPort(pin); 34 volatile uint8_t *reg; 35 36 if (port == NOT_A_PIN) return; 37 38 // JWS: can I let the optimizer do this? 39 reg = portModeRegister(port); 40 41 if (mode == INPUT) { 42 uint8_t oldSREG = SREG; 43 cli(); 44 *reg &= ~bit; 45 SREG = oldSREG; 46 } else { 47 uint8_t oldSREG = SREG; 48 cli(); 49 *reg |= bit; 50 SREG = oldSREG; 51 } 52 } 53 54 // Forcing this inline keeps the callers from having to push their own stuff 55 // on the stack. It is a good performance win and only takes 1 more byte per 56 // user than calling. (It will take more bytes on the 168.) 57 // 58 // But shouldn't this be moved into pinMode? Seems silly to check and do on 59 // each digitalread or write. 60 // 61 // Mark Sproul: 62 // - Removed inline. Save 170 bytes on atmega1280 63 // - changed to a switch statment; added 32 bytes but much easier to read and maintain. 64 // - Added more #ifdefs, now compiles for atmega645 65 // 66 //static inline void turnOffPWM(uint8_t timer) __attribute__ ((always_inline)); 67 //static inline void turnOffPWM(uint8_t timer) 68 static void turnOffPWM(uint8_t timer) 69 { 70 switch (timer) 71 { 72 #if defined(TCCR1A) && defined(COM1A1) 73 case TIMER1A: cbi(TCCR1A, COM1A1); break; 74 #endif 75 #if defined(TCCR1A) && defined(COM1B1) 76 case TIMER1B: cbi(TCCR1A, COM1B1); break; 77 #endif 78 79 #if defined(TCCR2) && defined(COM21) 80 case TIMER2: cbi(TCCR2, COM21); break; 81 #endif 82 83 #if defined(TCCR0A) && defined(COM0A1) 84 case TIMER0A: cbi(TCCR0A, COM0A1); break; 85 #endif 86 87 #if defined(TIMER0B) && defined(COM0B1) 88 case TIMER0B: cbi(TCCR0A, COM0B1); break; 89 #endif 90 #if defined(TCCR2A) && defined(COM2A1) 91 case TIMER2A: cbi(TCCR2A, COM2A1); break; 92 #endif 93 #if defined(TCCR2A) && defined(COM2B1) 94 case TIMER2B: cbi(TCCR2A, COM2B1); break; 95 #endif 96 97 #if defined(TCCR3A) && defined(COM3A1) 98 case TIMER3A: cbi(TCCR3A, COM3A1); break; 99 #endif 100 #if defined(TCCR3A) && defined(COM3B1) 101 case TIMER3B: cbi(TCCR3A, COM3B1); break; 102 #endif 103 #if defined(TCCR3A) && defined(COM3C1) 104 case TIMER3C: cbi(TCCR3A, COM3C1); break; 105 #endif 106 107 #if defined(TCCR4A) && defined(COM4A1) 108 case TIMER4A: cbi(TCCR4A, COM4A1); break; 109 #endif 110 #if defined(TCCR4A) && defined(COM4B1) 111 case TIMER4B: cbi(TCCR4A, COM4B1); break; 112 #endif 113 #if defined(TCCR4A) && defined(COM4C1) 114 case TIMER4C: cbi(TCCR4A, COM4C1); break; 115 #endif 116 #if defined(TCCR5A) 117 case TIMER5A: cbi(TCCR5A, COM5A1); break; 118 case TIMER5B: cbi(TCCR5A, COM5B1); break; 119 case TIMER5C: cbi(TCCR5A, COM5C1); break; 120 #endif 121 } 122 } 123 124 void digitalWrite(uint8_t pin, uint8_t val) 125 { 126 uint8_t timer = digitalPinToTimer(pin); 127 uint8_t bit = digitalPinToBitMask(pin); 128 uint8_t port = digitalPinToPort(pin); 129 volatile uint8_t *out; 130 131 if (port == NOT_A_PIN) return; 132 133 // If the pin that support PWM output, we need to turn it off 134 // before doing a digital write. 135 if (timer != NOT_ON_TIMER) turnOffPWM(timer); 136 137 out = portOutputRegister(port); 138 139 if (val == LOW) { 140 uint8_t oldSREG = SREG; 141 cli(); 142 *out &= ~bit; 143 SREG = oldSREG; 144 } else { 145 uint8_t oldSREG = SREG; 146 cli(); 147 *out |= bit; 148 SREG = oldSREG; 149 } 150 } 151 152 int digitalRead(uint8_t pin) 153 { 154 uint8_t timer = digitalPinToTimer(pin); 155 uint8_t bit = digitalPinToBitMask(pin); 156 uint8_t port = digitalPinToPort(pin); 157 158 if (port == NOT_A_PIN) return LOW; 159 160 // If the pin that support PWM output, we need to turn it off 161 // before getting a digital reading. 162 if (timer != NOT_ON_TIMER) turnOffPWM(timer); 163 164 if (*portInputRegister(port) & bit) return HIGH; 165 return LOW; 166 } 167
