Recover from display sleep, use LCD sleep function.

firmware/application/event_m0.cpp

@@ -86,6 +86,19 @@ void EventDispatcher::request_stop() {
 	is_running = false;
 }
 
+void EventDispatcher::set_display_sleep(const bool sleep) {
+	// TODO: Distribute display sleep message more broadly, shut down data generation
+	// on baseband side, since all that data is being discarded during sleep.
+	if( sleep ) {
+		portapack::io.lcd_backlight(false);
+		portapack::display.sleep();
+	} else {
+		portapack::display.wake();
+		portapack::io.lcd_backlight(true);
+	}
+	display_sleep = sleep;
+};
+
 eventmask_t EventDispatcher::wait() {
 	return chEvtWaitAny(ALL_EVENTS);
 }
@@ -99,15 +112,15 @@ void EventDispatcher::dispatch(const eventmask_t events) {
 		handle_rtc_tick();
 	}
 	
+	if( events & EVT_MASK_SWITCHES ) {
+		handle_switches();
+	}
+
 	if( !display_sleep ) {
 		if( events & EVT_MASK_LCD_FRAME_SYNC ) {
 			handle_lcd_frame_sync();
 		}
 
-		if( events & EVT_MASK_SWITCHES ) {
-			handle_switches();
-		}
-
 		if( events & EVT_MASK_ENCODER ) {
 			handle_encoder();
 		}
@@ -181,6 +194,15 @@ void EventDispatcher::handle_lcd_frame_sync() {
 
 void EventDispatcher::handle_switches() {
 	const auto switches_state = get_switches_state();
+
+	if( display_sleep ) {
+		// Swallow event, wake up display.
+		if( switches_state.any() ) {
+			set_display_sleep(false);
+		}
+		return;
+	}
+
 	for(size_t i=0; i<switches_state.size(); i++) {
 		// TODO: Ignore multiple keys at the same time?
 		if( switches_state[i] ) {

firmware/application/event_m0.hpp

@@ -55,10 +55,7 @@ public:
 	void run();
 	void request_stop();
 
-	void set_display_sleep(bool new_value) {
-		portapack::io.lcd_backlight(false);
-		display_sleep = new_value;
-	};
+	void set_display_sleep(const bool sleep);
 
 	static inline void events_flag(const eventmask_t events) {
 		if( thread_event_loop ) {

firmware/common/lcd_ili9341.cpp

@@ -41,6 +41,20 @@ void lcd_reset() {
 	chThdSleepMilliseconds(120);
 }
 
+void lcd_sleep_in() {
+	io.lcd_data_write_command_and_data(0x10, {});
+	chThdSleepMilliseconds(5);
+}
+
+void lcd_sleep_out() {
+	io.lcd_data_write_command_and_data(0x11, {});
+	chThdSleepMilliseconds(120);
+}
+
+void lcd_display_on() {
+	io.lcd_data_write_command_and_data(0x29, {});
+}
+
 void lcd_init() {
 	// LCDs are configured for IM[2:0] = 001
 	// 8080-I system, 16-bit parallel bus
@@ -147,12 +161,8 @@ void lcd_init() {
 		0x47, 0x04, 0x0C, 0x0B, 0x29, 0x2F, 0x05
 	});
 
-	// Exit Sleep
-	io.lcd_data_write_command_and_data(0x11, {});
-	chThdSleepMilliseconds(120);
-
-	// Display on
-	io.lcd_data_write_command_and_data(0x29, {});
+	lcd_sleep_out();
+	lcd_display_on();
 
 	// Turn on Tearing Effect Line (TE) output signal.
 	io.lcd_data_write_command_and_data(0x35, { 0b00000000 });
@@ -230,6 +240,14 @@ void ILI9341::shutdown() {
 	lcd_reset();
 }
 
+void ILI9341::sleep() {
+	lcd_sleep_in();
+}
+
+void ILI9341::wake() {
+	lcd_sleep_out();
+}
+
 void ILI9341::fill_rectangle(ui::Rect r, const ui::Color c) {
 	const auto r_clipped = r.intersect(screen_rect());
 	if( !r_clipped.is_empty() ) {

firmware/common/lcd_ili9341.hpp

@@ -44,6 +44,9 @@ public:
 	void init();
 	void shutdown();
 
+	void sleep();
+	void wake();
+
 	void fill_rectangle(ui::Rect r, const ui::Color c);
 	void fill_circle(
 		const ui::Point center,