Keyboard: Add new keyboard "Sol" from RGBKB (#4497)

* Add final RGBKB Sol firmware

* Apply suggestions from code review

Apply most of the changes noroadsleft has suggested

Co-Authored-By: Legonut <legonut3@gmail.com>

* Cleanup readme

* Cleanup keymaps per @noroadslefts suggestions

* Remove eeproms, use set_single_persistent_default_layer

* Suggestions from @noroadsleft and @drashna

some small cleanup

* Change RGB_SMOD to RGB_RMOD

* fix RGB_SMOD

* Apply suggestions from code review

Remove redundant lines

Co-Authored-By: Legonut <legonut3@gmail.com>

1 files changed, 54 insertions, 0 deletions

diff --git a/keyboards/sol/rev1/split_util.c b/keyboards/sol/rev1/split_util.c
new file mode 100644
index 000000000..c645bbdfe
--- /dev/null
+++ b/keyboards/sol/rev1/split_util.c
@@ -0,0 +1,54 @@
+#include <avr/io.h>
+#include <avr/wdt.h>
+#include <avr/power.h>
+#include <avr/interrupt.h>
+#include <util/delay.h>
+#include <avr/eeprom.h>
+#include "split_util.h"
+#include "matrix.h"
+#include "keyboard.h"
+#include "serial.h"
+
+volatile bool isLeftHand = true;
+
+static void setup_handedness(void) {
+  #ifdef EE_HANDS
+    isLeftHand = eeprom_read_byte(EECONFIG_HANDEDNESS);
+  #else
+    #if defined(MASTER_RIGHT)
+      isLeftHand = !has_usb();
+    #else
+      isLeftHand = has_usb();
+    #endif
+  #endif
+}
+
+static void keyboard_master_setup(void) {
+    serial_master_init();
+}
+
+static void keyboard_slave_setup(void) {
+    serial_slave_init();
+}
+
+bool has_usb(void) {
+   USBCON |= (1 << OTGPADE); //enables VBUS pad
+   _delay_us(5);
+   return (USBSTA & (1<<VBUS));  //checks state of VBUS
+}
+
+void split_keyboard_setup(void) {
+   setup_handedness();
+
+   if (has_usb()) {
+      keyboard_master_setup();
+   } else {
+      keyboard_slave_setup();
+   }
+   sei();
+}
+
+// this code runs before the usb and keyboard is initialized
+void matrix_setup(void) {
+    split_keyboard_setup();
+}