Move S_FMT to HAL, apply to mixer

Marlin/src/HAL/AVR/HAL.h

@@ -50,7 +50,8 @@
 // Defines
 // ------------------------
 
-//#define analogInputToDigitalPin(IO) IO
+// AVR PROGMEM extension for sprintf_P
+#define S_FMT "%S"
 
 #ifndef CRITICAL_SECTION_START
   #define CRITICAL_SECTION_START()  unsigned char _sreg = SREG; cli()
@@ -60,9 +61,6 @@
 #define ENABLE_ISRS()  sei()
 #define DISABLE_ISRS() cli()
 
-// On AVR this is in math.h?
-//#define square(x) ((x)*(x))
-
 // ------------------------
 // Types
 // ------------------------

Marlin/src/HAL/HAL.h

@@ -31,6 +31,11 @@
   #define I2C_ADDRESS(A) (A)
 #endif
 
+// Needed for AVR sprintf_P PROGMEM extension
+#ifndef S_FMT
+  #define S_FMT "%s"
+#endif
+
 inline void watchdog_refresh() {
   TERN_(USE_WATCHDOG, HAL_watchdog_refresh());
 }

Marlin/src/core/macros.h

@@ -76,13 +76,6 @@
 // Nanoseconds per cycle
 #define NANOSECONDS_PER_CYCLE (1000000000.0 / F_CPU)
 
-// Macros to make sprintf_P read from PROGMEM (AVR extension)
-#ifdef __AVR__
-  #define S_FMT "%S"
-#else
-  #define S_FMT "%s"
-#endif
-
 // Macros to make a string from a macro
 #define STRINGIFY_(M) #M
 #define STRINGIFY(M) STRINGIFY_(M)

Marlin/src/lcd/dogm/status_screen_DOGM.cpp

@@ -695,19 +695,19 @@ void MarlinUI::draw_status_screen() {
         // Two-component mix / gradient instead of XY
 
         char mixer_messages[12];
-        const char *mix_label;
+        PGM_P mix_label;
         #if ENABLED(GRADIENT_MIX)
           if (mixer.gradient.enabled) {
             mixer.update_mix_from_gradient();
-            mix_label = "Gr";
+            mix_label = PSTR("Gr");
           }
           else
         #endif
           {
             mixer.update_mix_from_vtool();
-            mix_label = "Mx";
+            mix_label = PSTR("Mx");
           }
-        sprintf_P(mixer_messages, PSTR("%s %d;%d%% "), mix_label, int(mixer.mix[0]), int(mixer.mix[1]));
+        sprintf_P(mixer_messages, PSTR(S_FMT " %d;%d%% "), mix_label, int(mixer.mix[0]), int(mixer.mix[1]));
         lcd_put_u8str(X_LABEL_POS, XYZ_BASELINE, mixer_messages);
 
       #else