From db878c9996c5df8bf9f1309728e224ac6cfa6005 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gu=C3=B0ni=20M=C3=A1r=20Gilbert?= <gudni.m.g@gmail.com>
Date: Sat, 11 Feb 2023 14:05:24 +0000
Subject: [PATCH] backlight: always allow backlight to dim/wake

This commit adds the ability for the firmware to dim and wake the
backlight when LCD updates are disabled. Such as in the MMU error screen
or when rendering full screen messages which typically
disable the LCD updates to prevent the status screen from rendering.

Fixes #2777

Change in memory:
Flash: -26 bytes
SRAM: +1 byte
---
 Firmware/lcd.cpp      | 16 ++++++++++++++--
 Firmware/sound.cpp    |  4 ----
 Firmware/ultralcd.cpp |  4 ----
 3 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/Firmware/lcd.cpp b/Firmware/lcd.cpp
index 93c410c8c..b5f45d2a9 100644
--- a/Firmware/lcd.cpp
+++ b/Firmware/lcd.cpp
@@ -15,6 +15,7 @@
 #include "fastio.h"
 //-//
 #include "sound.h"
+#include "backlight.h"
 
 #define LCD_DEFAULT_DELAY 100
 
@@ -638,6 +639,7 @@ int8_t lcd_encoder_diff = 0;
 uint8_t lcd_buttons = 0;
 uint8_t lcd_button_pressed = 0;
 uint8_t lcd_update_enabled = 1;
+static bool lcd_backlight_wake_trigger; // Flag set by interrupt when the knob is pressed or rotated
 
 uint32_t lcd_next_update_millis = 0;
 
@@ -695,8 +697,16 @@ void lcd_update(uint8_t lcdDrawUpdateOverride)
 {
 	if (lcd_draw_update < lcdDrawUpdateOverride)
 		lcd_draw_update = lcdDrawUpdateOverride;
-	if (!lcd_update_enabled)
-		return;
+
+	if (lcd_backlight_wake_trigger) {
+		lcd_backlight_wake_trigger = false;
+		backlight_wake();
+	}
+
+	backlight_update();
+
+	if (!lcd_update_enabled) return;
+
 	if (lcd_lcdupdate_func)
 		lcd_lcdupdate_func();
 }
@@ -742,6 +752,7 @@ void lcd_buttons_update(void)
         if (!buttonBlanking.running() || buttonBlanking.expired(BUTTON_BLANKING_TIME)) {
             buttonBlanking.start();
             safetyTimer.start();
+            lcd_backlight_wake_trigger = true; // flag event, knob pressed
             if ((lcd_button_pressed == 0) && (lcd_long_press_active == 0))
             {
                 longPressTimer.start();
@@ -776,6 +787,7 @@ void lcd_buttons_update(void)
 	if (lcd_buttons & EN_B) enc |= B10;
 	if (enc != lcd_encoder_bits)
 	{
+		lcd_backlight_wake_trigger = true; // flag event, knob rotated
 		switch (enc)
 		{
 		case encrot0:
diff --git a/Firmware/sound.cpp b/Firmware/sound.cpp
index 5cb736683..9630aacb7 100644
--- a/Firmware/sound.cpp
+++ b/Firmware/sound.cpp
@@ -56,7 +56,6 @@ Sound_SaveMode();
 
 //if critical is true then silend and once mode is ignored
 void __attribute__((noinline)) Sound_MakeCustom(uint16_t ms,uint16_t tone_,bool critical){
-    backlight_wake();
      if (critical || eSoundMode != e_SOUND_MODE_SILENT) {
           if(!tone_) {
                WRITE(BEEPER, HIGH);
@@ -127,7 +126,6 @@ static void Sound_DoSound_Blind_Alert(void)
 
  static void Sound_DoSound_Encoder_Move(void)
 {
-    backlight_wake();
 uint8_t nI;
 
  for(nI=0;nI<5;nI++)
@@ -141,7 +139,6 @@ uint8_t nI;
 
 static void Sound_DoSound_Echo(void)
 {
-    backlight_wake();
 uint8_t nI;
 
 for(nI=0;nI<10;nI++)
@@ -163,7 +160,6 @@ WRITE(BEEPER,LOW);
 
 static void Sound_DoSound_Alert(bool bOnce)
 {
-    backlight_wake();
 uint8_t nI,nMax;
 
 nMax=bOnce?1:3;
diff --git a/Firmware/ultralcd.cpp b/Firmware/ultralcd.cpp
index 9f8ed8f45..8a395b1f2 100644
--- a/Firmware/ultralcd.cpp
+++ b/Firmware/ultralcd.cpp
@@ -7446,7 +7446,6 @@ void menu_lcd_longpress_func(void)
     // Wake up the LCD backlight and,
     // start LCD inactivity timer
     lcd_timeoutToStatus.start();
-    backlight_wake();
     if (homing_flag || mesh_bed_leveling_flag || menu_menu == lcd_babystep_z || menu_menu == lcd_move_z || menu_block_mask != MENU_BLOCK_NONE || Stopped)
     {
         // disable longpress during re-entry, while homing, calibration or if a serious error
@@ -7551,7 +7550,6 @@ void menu_lcd_lcdupdate_func(void)
 		}
 	}
 #endif//CARDINSERTED
-	backlight_update();
 	if (lcd_next_update_millis < _millis())
 	{
 		if (abs(lcd_encoder_diff) >= ENCODER_PULSES_PER_STEP)
@@ -7562,13 +7560,11 @@ void menu_lcd_lcdupdate_func(void)
 			Sound_MakeSound(e_SOUND_TYPE_EncoderMove);
 			lcd_encoder_diff = 0;
 			lcd_timeoutToStatus.start();
-			backlight_wake();
 		}
 
 		if (LCD_CLICKED)
 		{
 			lcd_timeoutToStatus.start();
-			backlight_wake();
 		}
 
 		(*menu_menu)();