sanguino/cores/arduino/wiring_digital.c

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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 }

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