tmk_core/protocol/usb_hid/arduino-1.0.1/cores/arduino/wiring_digital.c

   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 #define ARDUINO_MAIN
  28 #include "wiring_private.h"
  29 #include "pins_arduino.h"
  30
  31 void pinMode(uint8_t pin, uint8_t mode)
  32 {
  33         uint8_t bit = digitalPinToBitMask(pin);
  34         uint8_t port = digitalPinToPort(pin);
  35         volatile uint8_t *reg, *out;
  36
  37         if (port == NOT_A_PIN) return;
  38
  39         // JWS: can I let the optimizer do this?
  40         reg = portModeRegister(port);
  41         out = portOutputRegister(port);
  42
  43         if (mode == INPUT) {
  44                 uint8_t oldSREG = SREG;
  45                 cli();
  46                 *reg &= ~bit;
  47                 *out &= ~bit;
  48                 SREG = oldSREG;
  49         } else if (mode == INPUT_PULLUP) {
  50                 uint8_t oldSREG = SREG;
  51                 cli();
  52                 *reg &= ~bit;
  53                 *out |= bit;
  54                 SREG = oldSREG;
  55         } else {
  56                 uint8_t oldSREG = SREG;
  57                 cli();
  58                 *reg |= bit;
  59                 SREG = oldSREG;
  60         }
  61 }
  62
  63 // Forcing this inline keeps the callers from having to push their own stuff
  64 // on the stack. It is a good performance win and only takes 1 more byte per
  65 // user than calling. (It will take more bytes on the 168.)
  66 //
  67 // But shouldn't this be moved into pinMode? Seems silly to check and do on
  68 // each digitalread or write.
  69 //
  70 // Mark Sproul:
  71 // - Removed inline. Save 170 bytes on atmega1280
  72 // - changed to a switch statment; added 32 bytes but much easier to read and maintain.
  73 // - Added more #ifdefs, now compiles for atmega645
  74 //
  75 //static inline void turnOffPWM(uint8_t timer) __attribute__ ((always_inline));
  76 //static inline void turnOffPWM(uint8_t timer)
  77 static void turnOffPWM(uint8_t timer)
  78 {
  79         switch (timer)
  80         {
  81                 #if defined(TCCR1A) && defined(COM1A1)
  82                 case TIMER1A:   cbi(TCCR1A, COM1A1);    break;
  83                 #endif
  84                 #if defined(TCCR1A) && defined(COM1B1)
  85                 case TIMER1B:   cbi(TCCR1A, COM1B1);    break;
  86                 #endif
  87
  88                 #if defined(TCCR2) && defined(COM21)
  89                 case  TIMER2:   cbi(TCCR2, COM21);      break;
  90                 #endif
  91
  92                 #if defined(TCCR0A) && defined(COM0A1)
  93                 case  TIMER0A:  cbi(TCCR0A, COM0A1);    break;
  94                 #endif
  95
  96                 #if defined(TIMER0B) && defined(COM0B1)
  97                 case  TIMER0B:  cbi(TCCR0A, COM0B1);    break;
  98                 #endif
  99                 #if defined(TCCR2A) && defined(COM2A1)
 100                 case  TIMER2A:  cbi(TCCR2A, COM2A1);    break;
 101                 #endif
 102                 #if defined(TCCR2A) && defined(COM2B1)
 103                 case  TIMER2B:  cbi(TCCR2A, COM2B1);    break;
 104                 #endif
 105
 106                 #if defined(TCCR3A) && defined(COM3A1)
 107                 case  TIMER3A:  cbi(TCCR3A, COM3A1);    break;
 108                 #endif
 109                 #if defined(TCCR3A) && defined(COM3B1)
 110                 case  TIMER3B:  cbi(TCCR3A, COM3B1);    break;
 111                 #endif
 112                 #if defined(TCCR3A) && defined(COM3C1)
 113                 case  TIMER3C:  cbi(TCCR3A, COM3C1);    break;
 114                 #endif
 115
 116                 #if defined(TCCR4A) && defined(COM4A1)
 117                 case  TIMER4A:  cbi(TCCR4A, COM4A1);    break;
 118                 #endif
 119                 #if defined(TCCR4A) && defined(COM4B1)
 120                 case  TIMER4B:  cbi(TCCR4A, COM4B1);    break;
 121                 #endif
 122                 #if defined(TCCR4A) && defined(COM4C1)
 123                 case  TIMER4C:  cbi(TCCR4A, COM4C1);    break;
 124                 #endif
 125                 #if defined(TCCR4C) && defined(COM4D1)
 126                 case TIMER4D:   cbi(TCCR4C, COM4D1);    break;
 127                 #endif
 128
 129                 #if defined(TCCR5A)
 130                 case  TIMER5A:  cbi(TCCR5A, COM5A1);    break;
 131                 case  TIMER5B:  cbi(TCCR5A, COM5B1);    break;
 132                 case  TIMER5C:  cbi(TCCR5A, COM5C1);    break;
 133                 #endif
 134         }
 135 }
 136
 137 void digitalWrite(uint8_t pin, uint8_t val)
 138 {
 139         uint8_t timer = digitalPinToTimer(pin);
 140         uint8_t bit = digitalPinToBitMask(pin);
 141         uint8_t port = digitalPinToPort(pin);
 142         volatile uint8_t *out;
 143
 144         if (port == NOT_A_PIN) return;
 145
 146         // If the pin that support PWM output, we need to turn it off
 147         // before doing a digital write.
 148         if (timer != NOT_ON_TIMER) turnOffPWM(timer);
 149
 150         out = portOutputRegister(port);
 151
 152         uint8_t oldSREG = SREG;
 153         cli();
 154
 155         if (val == LOW) {
 156                 *out &= ~bit;
 157         } else {
 158                 *out |= bit;
 159         }
 160
 161         SREG = oldSREG;
 162 }
 163
 164 int digitalRead(uint8_t pin)
 165 {
 166         uint8_t timer = digitalPinToTimer(pin);
 167         uint8_t bit = digitalPinToBitMask(pin);
 168         uint8_t port = digitalPinToPort(pin);
 169
 170         if (port == NOT_A_PIN) return LOW;
 171
 172         // If the pin that support PWM output, we need to turn it off
 173         // before getting a digital reading.
 174         if (timer != NOT_ON_TIMER) turnOffPWM(timer);
 175
 176         if (*portInputRegister(port) & bit) return HIGH;
 177         return LOW;
 178 }