qmk-firmware/keyboards/e6v2/le/le.c

#include "le.h"

void matrix_init_kb(void) {
	// put your keyboard start-up code here
	// runs once when the firmware starts up

	matrix_init_user();
}

void matrix_scan_kb(void) {
	// put your looping keyboard code here
	// runs every cycle (a lot)

	matrix_scan_user();
}

bool process_record_kb(uint16_t keycode, keyrecord_t *record) {
	// put your per-action keyboard code here
	// runs for every action, just before processing by the firmware

	return process_record_user(keycode, record);
}

void led_set_user(uint8_t usb_led) {
	if (usb_led & (1 << USB_LED_CAPS_LOCK)) {
		DDRB |= (1 << 7); 
		PORTB &= ~(1 << 7);
	} else {
		DDRB &= ~(1 << 7); 
		PORTB &= ~(1 << 7);
	}
}