Compiling: quantum/quantum.c                                                                       quantum/quantum.c: In function ‘set_pwm’:
quantum/quantum.c:1286:2: error: ‘OCRxx’ undeclared (first use in this function)
  OCRxx = val;
  ^
quantum/quantum.c:1286:2: note: each undeclared identifier is reported only once for each function it appears in
quantum/quantum.c: In function ‘backlight_set’:
quantum/quantum.c:1297:5: error: ‘TCCRxA’ undeclared (first use in this function)
     TCCRxA &= ~(_BV(COMxx1));
     ^
In file included from /usr/lib/avr/include/avr/io.h:99:0,
                 from quantum/config_common.h:29,
                 from ./keyboards/jj4x4/config.h:20,
                 from <command-line>:0:
quantum/quantum.c:1297:21: error: ‘COMxx1’ undeclared (first use in this function)
     TCCRxA &= ~(_BV(COMxx1));
                     ^
quantum/quantum.c: In function ‘is_breathing’:
quantum/quantum.c:1321:15: error: ‘TIMSK1’ undeclared (first use in this function)
     return !!(TIMSK1 & _BV(TOIE1));
               ^
quantum/quantum.c: In function ‘breathing_enable’:
quantum/quantum.c:1324:42: error: ‘TIMSK1’ undeclared (first use in this function)
 #define breathing_interrupt_enable() do {TIMSK1 |= _BV(TOIE1);} while (0)
                                          ^
quantum/quantum.c:1333:3: note: in expansion of macro ‘breathing_interrupt_enable’
   breathing_interrupt_enable();
   ^
quantum/quantum.c: In function ‘breathing_pulse’:
quantum/quantum.c:1324:42: error: ‘TIMSK1’ undeclared (first use in this function)
 #define breathing_interrupt_enable() do {TIMSK1 |= _BV(TOIE1);} while (0)
                                          ^
quantum/quantum.c:1343:5: note: in expansion of macro ‘breathing_interrupt_enable’
     breathing_interrupt_enable();
     ^
quantum/quantum.c: In function ‘breathing_disable’:
quantum/quantum.c:1325:43: error: ‘TIMSK1’ undeclared (first use in this function)
 #define breathing_interrupt_disable() do {TIMSK1 &= ~_BV(TOIE1);} while (0)
                                           ^
quantum/quantum.c:1348:5: note: in expansion of macro ‘breathing_interrupt_disable’
     breathing_interrupt_disable();
     ^
quantum/quantum.c: In function ‘__vector_9’:
quantum/quantum.c:1325:43: error: ‘TIMSK1’ undeclared (first use in this function)
 #define breathing_interrupt_disable() do {TIMSK1 &= ~_BV(TOIE1);} while (0)
                                           ^
quantum/quantum.c:1412:7: note: in expansion of macro ‘breathing_interrupt_disable’
       breathing_interrupt_disable();
       ^
quantum/quantum.c: In function ‘backlight_init_ports’:
quantum/quantum.c:1448:3: error: ‘TCCRxA’ undeclared (first use in this function)
   TCCRxA = _BV(COMxx1) | _BV(WGM11); // = 0b00001010;
   ^
In file included from /usr/lib/avr/include/avr/io.h:99:0,
                 from quantum/config_common.h:29,
                 from ./keyboards/jj4x4/config.h:20,
                 from <command-line>:0:
quantum/quantum.c:1448:16: error: ‘COMxx1’ undeclared (first use in this function)
   TCCRxA = _BV(COMxx1) | _BV(WGM11); // = 0b00001010;
                ^
quantum/quantum.c:1449:3: error: ‘TCCRxB’ undeclared (first use in this function)
   TCCRxB = _BV(WGM13) | _BV(WGM12) | _BV(CS10); // = 0b00011001;
   ^
quantum/quantum.c:1451:3: error: ‘ICRx’ undeclared (first use in this function)
   ICRx = TIMER_TOP;
   ^
quantum/quantum.c: In function ‘is_breathing’:
quantum/quantum.c:1322:1: error: control reaches end of non-void function [-Werror=return-type]
 }
 ^
cc1: all warnings being treated as errors