Backlight and RGB now working for JJ50 (#2929)

* Added support for JJ50 from KPRepublic, no rgb or backlight control yet. Added as a layout of ymd96 at the moment (same microprocessor). Basic keymap with three layers to get started.

* Added support for JJ50

* Tidied up jj50 code, backlight and RGB is now working.

* Renaming "KEYMAP" to "LAYOUT" to adhere to the new QMK standards.

keyboards/jj50/jj50.c

@@ -16,7 +16,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 #include "jj50.h"
-#include "rgblight.h"
 
 #include <avr/pgmspace.h>
 
@@ -24,22 +23,72 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "i2c.h"
 #include "quantum.h"
 
+#include "backlight.h"
+#include "backlight_custom.h"
+
+// for keyboard subdirectory level init functions
+// @Override
+void matrix_init_kb(void) {
+    // call user level keymaps, if any
+    matrix_init_user();
+}
+
+#ifdef BACKLIGHT_ENABLE
+/// Overrides functions in `quantum.c`
+void backlight_init_ports(void) {
+    b_led_init_ports();
+}
+
+void backlight_task(void) {
+    b_led_task();
+}
+
+void backlight_set(uint8_t level) {
+    b_led_set(level);
+}
+#endif
+
+#ifdef RGBLIGHT_ENABLE
 extern rgblight_config_t rgblight_config;
 
+// custom RGB driver
 void rgblight_set(void) {
     if (!rgblight_config.enable) {
-        for (uint8_t i = 0; i < RGBLED_NUM; i++) {
+        for (uint8_t i=0; i<RGBLED_NUM; i++) {
             led[i].r = 0;
             led[i].g = 0;
             led[i].b = 0;
         }
     }
-
+    
     i2c_init();
     i2c_send(0xb0, (uint8_t*)led, 3 * RGBLED_NUM);
 }
 
-__attribute__ ((weak))
-void matrix_scan_user(void) {
+bool rgb_init = false;
+
+void matrix_scan_kb(void) {
+    // if LEDs were previously on before poweroff, turn them back on
+    if (rgb_init == false && rgblight_config.enable) {
+        i2c_init();
+        i2c_send(0xb0, (uint8_t*)led, 3 * RGBLED_NUM);
+        rgb_init = true;
+    }
+    
     rgblight_task();
-}
+#else
+    void matrix_scan_kb(void) {
+#endif
+        matrix_scan_user();
+        /* Nothing else for now. */
+    }
+    
+    __attribute__((weak)) // overridable
+    void matrix_init_user(void) {
+        
+    }
+    
+    __attribute__((weak)) // overridable
+    void matrix_scan_user(void) {
+        
+    }