Add arch.idle() command

include/arch.h

@@ -9,6 +9,7 @@ class Arch {
 		Arch () {}
 		void setup();
 		void idle_loop();
+		void idle();
 		void delay_us(unsigned char const us);
 };
 

src/arch/arduino-nano/arch.cc

@@ -55,6 +55,14 @@ void Arch::idle_loop(void)
 	}
 }
 
+void Arch::idle(void)
+{
+	SMCR = _BV(SE);
+	asm("sleep");
+	SMCR = 0;
+	asm("wdr");
+}
+
 void Arch::delay_us(unsigned char const us)
 {
 	__builtin_avr_delay_cycles(1600);

src/arch/esp8266/arch.cc

@@ -57,6 +57,10 @@ void Arch::idle_loop(void)
 {
 }
 
+void ArcH::idle(void)
+{
+}
+
 extern "C" void user_init(void)
 {
 	system_init_done_cb(jump_to_main);

src/arch/msp430fr5969lp/arch.cc

@@ -91,6 +91,17 @@ void Arch::idle_loop(void)
 	}
 }
 
+void Arch::idle(void)
+{
+	__eint();
+	asm volatile("nop");
+	__bis_SR_register(LPM2_bits);
+	asm volatile("nop");
+#ifdef WITH_WAKEUP
+		wakeup();
+#endif
+}
+
 Arch arch;
 
 #if defined(WITH_LOOP) || defined(TIMER_S)

src/arch/posix/arch.cc

@@ -10,4 +10,8 @@ void Arch::idle_loop(void)
 	}
 }
 
+void Arch::idle(void)
+{
+}
+
 Arch arch;