ARM split - Add bootmagic/magic keycodes for setting handedness (#6545)

* Add docs on bootmagic/magic keycodes for setting handedness

* Clang format fixes

* Maintain backwards compatibility

* Maintain backwards compatibility

3 files changed, 10 insertions, 3 deletions

diff --git a/quantum/quantum.c b/quantum/quantum.c
index ec80fa557..16922dd01 100644
--- a/quantum/quantum.c
+++ b/quantum/quantum.c
@@ -544,7 +544,7 @@ bool process_record_quantum(keyrecord_t *record) {
 #    endif
 #endif
         case MAGIC_SWAP_CONTROL_CAPSLOCK ... MAGIC_TOGGLE_ALT_GUI:
-        case MAGIC_SWAP_LCTL_LGUI ... MAGIC_TOGGLE_CTL_GUI:
+        case MAGIC_SWAP_LCTL_LGUI ... MAGIC_EE_HANDS_RIGHT:
             if (record->event.pressed) {
                 // MAGIC actions (BOOTMAGIC without the boot)
                 if (!eeconfig_is_enabled()) {
@@ -662,6 +662,12 @@ bool process_record_quantum(keyrecord_t *record) {
                     case MAGIC_TOGGLE_NKRO:
                         keymap_config.nkro = !keymap_config.nkro;
                         break;
+                    case MAGIC_EE_HANDS_LEFT:
+                        eeconfig_update_handedness(true);
+                        break;
+                    case MAGIC_EE_HANDS_RIGHT:
+                        eeconfig_update_handedness(false);
+                        break;
                     default:
                         break;
                 }
diff --git a/quantum/quantum_keycodes.h b/quantum/quantum_keycodes.h
index af984a7cd..5fac6a5ca 100644
--- a/quantum/quantum_keycodes.h
+++ b/quantum/quantum_keycodes.h
@@ -502,6 +502,8 @@ enum quantum_keycodes {
     MAGIC_SWAP_CTL_GUI,
     MAGIC_UNSWAP_CTL_GUI,
     MAGIC_TOGGLE_CTL_GUI,
+    MAGIC_EE_HANDS_LEFT,
+    MAGIC_EE_HANDS_RIGHT,
 
     // always leave at the end
     SAFE_RANGE
diff --git a/quantum/split_common/split_util.c b/quantum/split_common/split_util.c
index 5114b188e..d16a98977 100644
--- a/quantum/split_common/split_util.c
+++ b/quantum/split_common/split_util.c
@@ -7,7 +7,6 @@
 #include "quantum.h"
 
 #ifdef EE_HANDS
-#    include "tmk_core/common/eeprom.h"
 #    include "eeconfig.h"
 #endif
 
@@ -23,7 +22,7 @@ __attribute__((weak)) bool is_keyboard_left(void) {
     setPinInput(SPLIT_HAND_PIN);
     return readPin(SPLIT_HAND_PIN);
 #elif defined(EE_HANDS)
-    return eeprom_read_byte(EECONFIG_HANDEDNESS);
+    return eeconfig_read_handedness();
 #elif defined(MASTER_RIGHT)
     return !is_keyboard_master();
 #endif