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authorDavid A. Mellis <d.mellis@arduino.cc>2011-02-11 19:29:46 -0500
committerDavid A. Mellis <d.mellis@arduino.cc>2011-02-11 19:29:46 -0500
commiteed15e48d68d10426e015515ec4143849739f2de (patch)
tree4fc54101c58590a6c1c7225a60d223797f4e198b /cores/arduino/wiring.h
parent3696fa044687542ee6b4a9bc488348e184ee3ae2 (diff)
Changes to optimized digitalWrte(), etc.
Factoring out the implementation of digitalWrite(), digitalRead(), and pinMode() into macros that can either be inlined (for constant pin numbers) or executed within a function (non-constant pins). Removing testing for timers on pins in digitalWrite(), digitalRead(), and pinMode(). Moving pin to port macros from pins_arduino.h to wiring.h.
Diffstat (limited to 'cores/arduino/wiring.h')
-rwxr-xr-xcores/arduino/wiring.h148
1 files changed, 108 insertions, 40 deletions
diff --git a/cores/arduino/wiring.h b/cores/arduino/wiring.h
index 433c87e..66ce2f7 100755
--- a/cores/arduino/wiring.h
+++ b/cores/arduino/wiring.h
@@ -130,68 +130,136 @@ void detachInterrupt(uint8_t);
void setup(void);
void loop(void);
+INLINED uint8_t digitalPinToPort(uint8_t pin) {
+ if (__builtin_constant_p(pin))
+ return inlined_digitalPinToPort(pin);
+ else
+ return pgm_read_byte( digital_pin_to_port_PGM + pin );
+}
+
+INLINED uint8_t digitalPinToBitMask(uint8_t pin) {
+ if (__builtin_constant_p(pin))
+ return inlined_digitalPinToBitMask(pin);
+ else
+ return pgm_read_byte( digital_pin_to_bit_mask_PGM + pin );
+}
+
+INLINED uint8_t digitalPinToTimer(uint8_t pin) {
+ if (__builtin_constant_p(pin))
+ return inlined_digitalPinToTimer(pin);
+ else
+ return pgm_read_byte( digital_pin_to_timer_PGM + pin );
+}
+
+INLINED volatile uint8_t *portOutputRegister(uint8_t index) {
+ if (__builtin_constant_p(index))
+ return inlined_portOutputRegister(index);
+ else
+ return (volatile uint8_t *)( pgm_read_word( port_to_output_PGM + index ) );
+}
+
+INLINED volatile uint8_t* portInputRegister(uint8_t index) {
+ if (__builtin_constant_p(index))
+ return inlined_portInputRegister(index);
+ else
+ return (volatile uint8_t *)( pgm_read_word( port_to_input_PGM + index) );
+}
+
+INLINED volatile uint8_t* portModeRegister(uint8_t index) {
+ if (__builtin_constant_p(index))
+ return inlined_portModeRegister(index);
+ else
+ return (volatile uint8_t *)( pgm_read_word( port_to_mode_PGM + index) );
+}
+
/*
* Check if a given pin requires locking.
* When accessing lower 32 IO ports we can use SBI/CBI instructions, which are atomic. However
* other IO ports require load+modify+store and we need to make them atomic by disabling
* interrupts.
*/
-INLINED int portWriteNeedsLocking(uint8_t pin)
+INLINED int registerWriteNeedsLocking(volatile uint8_t *reg)
{
/* SBI/CBI instructions only work on lower 32 IO ports */
- if (inlined_portOutputRegister(inlined_digitalPinToPort(pin)) > (volatile uint8_t*)&_SFR_IO8(0x1F)) {
+ if (reg > (volatile uint8_t*)&_SFR_IO8(0x1F)) {
return 1;
}
return 0;
}
-/*
- * These functions will perform OR/AND on a given register, and are atomic.
- */
-extern void __digitalWriteOR_locked(volatile uint8_t*out, uint8_t bit);
-extern void __digitalWriteAND_locked(volatile uint8_t*out, uint8_t bit);
-
+#define digitalWrite_implementation(pin, value)\
+do {\
+ uint8_t oldSREG;\
+ uint8_t bit = digitalPinToBitMask(pin);\
+ uint8_t port = digitalPinToPort(pin);\
+ volatile uint8_t *reg = portOutputRegister(port);\
+\
+ if (!__builtin_constant_p(pin) || registerWriteNeedsLocking(reg)) {\
+ oldSREG = SREG;\
+ cli();\
+ }\
+\
+ if (value == LOW) {\
+ *reg &= ~bit;\
+ } else {\
+ *reg |= bit;\
+ }\
+\
+ if (!__builtin_constant_p(pin) || registerWriteNeedsLocking(reg)) {\
+ SREG = oldSREG;\
+ }\
+} while(0)
+
INLINED void digitalWrite(uint8_t pin, uint8_t value)
{
- if (__builtin_constant_p(pin)) {
- if (portWriteNeedsLocking(pin)) {
- if (value==LOW) {
- __digitalWriteAND_locked(inlined_portOutputRegister(inlined_digitalPinToPort(pin)),~inlined_digitalPinToBitMask(pin));
- } else {
- __digitalWriteOR_locked(inlined_portOutputRegister(inlined_digitalPinToPort(pin)),inlined_digitalPinToBitMask(pin));
- }
- } else {
- if (value==LOW) {
- *inlined_portOutputRegister(inlined_digitalPinToPort(pin)) &= ~(inlined_digitalPinToBitMask(pin));
- } else {
- *inlined_portOutputRegister(inlined_digitalPinToPort(pin)) |= inlined_digitalPinToBitMask(pin);
- }
- }
- } else {
- digitalWrite_lookup(pin,value);
- }
+ if (__builtin_constant_p(pin)) digitalWrite_implementation(pin, value);
+ else digitalWrite_lookup(pin, value);
}
-INLINED void pinMode(uint8_t pin, uint8_t mode)
+#define pinMode_implementation(pin, value)\
+do {\
+ uint8_t bit = digitalPinToBitMask(pin);\
+ uint8_t oldSREG;\
+ uint8_t port = digitalPinToPort(pin);\
+ volatile uint8_t *reg = portModeRegister(port);\
+\
+ if (!__builtin_constant_p(pin) || registerWriteNeedsLocking(reg)) {\
+ oldSREG = SREG;\
+ cli();\
+ }\
+\
+ if (value == INPUT) { \
+ *reg &= ~bit;\
+ } else {\
+ *reg |= bit;\
+ }\
+\
+ if (!__builtin_constant_p(pin) || registerWriteNeedsLocking(reg)) {\
+ SREG = oldSREG;\
+ }\
+} while(0)
+
+INLINED void pinMode(uint8_t pin, uint8_t value)
{
- if (__builtin_constant_p(pin)) {
- if (mode==INPUT) {
- *inlined_portModeRegister(inlined_digitalPinToPort(pin)) &= ~(inlined_digitalPinToBitMask(pin));
- } else {
- *inlined_portModeRegister(inlined_digitalPinToPort(pin)) |= inlined_digitalPinToBitMask(pin);
- }
- } else {
- pinMode_lookup(pin,mode);
- }
+ if (__builtin_constant_p(pin)) pinMode_implementation(pin, value);
+ else pinMode_lookup(pin, value);
}
+#define digitalRead_implementation(pin)\
+do {\
+ uint8_t bit = digitalPinToBitMask(pin);\
+ uint8_t port = digitalPinToPort(pin);\
+\
+ if (port == NOT_A_PIN) return LOW;\
+\
+ if (*portInputRegister(port) & bit) return HIGH;\
+ return LOW;\
+} while(0)
+
INLINED int digitalRead(uint8_t pin)
{
- if (__builtin_constant_p(pin)) {
- return !! *inlined_portInputRegister(inlined_digitalPinToPort(pin));
- } else {
- return digitalRead_lookup(pin);
- }
+ if (__builtin_constant_p(pin)) digitalRead_implementation(pin);
+ else return digitalRead_lookup(pin);
}