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

4 files changed, 34 insertions, 2 deletions

diff --git a/tmk_core/common/bootmagic.c b/tmk_core/common/bootmagic.c
index 09b1664c9..bb2aa0db8 100644
--- a/tmk_core/common/bootmagic.c
+++ b/tmk_core/common/bootmagic.c
@@ -122,6 +122,14 @@ void bootmagic(void) {
         default_layer = eeconfig_read_default_layer();
         default_layer_set((layer_state_t)default_layer);
     }
+
+    /* EE_HANDS handedness */
+    if (bootmagic_scan_keycode(BOOTMAGIC_KEY_EE_HANDS_LEFT)) {
+        eeconfig_update_handedness(true);
+    }
+    if (bootmagic_scan_keycode(BOOTMAGIC_KEY_EE_HANDS_RIGHT)) {
+        eeconfig_update_handedness(false);
+    }
 }
 
 /** \brief Scan Keycode
diff --git a/tmk_core/common/bootmagic.h b/tmk_core/common/bootmagic.h
index fb7647257..c64dc1785 100644
--- a/tmk_core/common/bootmagic.h
+++ b/tmk_core/common/bootmagic.h
@@ -36,6 +36,12 @@
 #ifndef BOOTMAGIC_KEY_DEBUG_MOUSE
 #    define BOOTMAGIC_KEY_DEBUG_MOUSE KC_M
 #endif
+#ifndef BOOTMAGIC_KEY_EE_HANDS_LEFT
+#    define BOOTMAGIC_KEY_EE_HANDS_LEFT KC_L
+#endif
+#ifndef BOOTMAGIC_KEY_EE_HANDS_RIGHT
+#    define BOOTMAGIC_KEY_EE_HANDS_RIGHT KC_R
+#endif
 
 /*
  * keymap config
diff --git a/tmk_core/common/eeconfig.c b/tmk_core/common/eeconfig.c
index 61aaec205..933ac42bd 100644
--- a/tmk_core/common/eeconfig.c
+++ b/tmk_core/common/eeconfig.c
@@ -153,8 +153,8 @@ uint32_t eeconfig_read_kb(void) { return eeprom_read_dword(EECONFIG_KEYBOARD); }
  *
  * FIXME: needs doc
  */
-
 void eeconfig_update_kb(uint32_t val) { eeprom_update_dword(EECONFIG_KEYBOARD, val); }
+
 /** \brief eeconfig read user
  *
  * FIXME: needs doc
@@ -166,9 +166,24 @@ uint32_t eeconfig_read_user(void) { return eeprom_read_dword(EECONFIG_USER); }
  */
 void eeconfig_update_user(uint32_t val) { eeprom_update_dword(EECONFIG_USER, val); }
 
+/** \brief eeconfig read haptic
+ *
+ * FIXME: needs doc
+ */
 uint32_t eeconfig_read_haptic(void) { return eeprom_read_dword(EECONFIG_HAPTIC); }
-/** \brief eeconfig update user
+/** \brief eeconfig update haptic
  *
  * FIXME: needs doc
  */
 void eeconfig_update_haptic(uint32_t val) { eeprom_update_dword(EECONFIG_HAPTIC, val); }
+
+/** \brief eeconfig read split handedness
+ *
+ * FIXME: needs doc
+ */
+bool eeconfig_read_handedness(void) { return !!eeprom_read_byte(EECONFIG_HANDEDNESS); }
+/** \brief eeconfig update split handedness
+ *
+ * FIXME: needs doc
+ */
+void eeconfig_update_handedness(bool val) { eeprom_update_byte(EECONFIG_HANDEDNESS, !!val); }
diff --git a/tmk_core/common/eeconfig.h b/tmk_core/common/eeconfig.h
index aea4eff9f..308f865e1 100644
--- a/tmk_core/common/eeconfig.h
+++ b/tmk_core/common/eeconfig.h
@@ -107,4 +107,7 @@ uint32_t eeconfig_read_haptic(void);
 void     eeconfig_update_haptic(uint32_t val);
 #endif
 
+bool eeconfig_read_handedness(void);
+void eeconfig_update_handedness(bool val);
+
 #endif