diff --git a/board/boards/black.h b/board/boards/black.h
index 043df7ed..f411d61f 100644
--- a/board/boards/black.h
+++ b/board/boards/black.h
@@ -202,6 +202,5 @@ const board board_black = {
   .set_fan_enabled = unused_set_fan_enabled,
   .set_ir_power = unused_set_ir_power,
   .set_phone_power = unused_set_phone_power,
-  .set_clock_source_mode = unused_set_clock_source_mode,
   .set_siren = unused_set_siren
 };
diff --git a/board/boards/board_declarations.h b/board/boards/board_declarations.h
index b00f39fc..9b8124b2 100644
--- a/board/boards/board_declarations.h
+++ b/board/boards/board_declarations.h
@@ -10,7 +10,6 @@ typedef uint32_t (*board_read_current)(void);
 typedef void (*board_set_ir_power)(uint8_t percentage);
 typedef void (*board_set_fan_enabled)(bool enabled);
 typedef void (*board_set_phone_power)(bool enabled);
-typedef void (*board_set_clock_source_mode)(uint8_t mode);
 typedef void (*board_set_siren)(bool enabled);
 typedef void (*board_board_tick)(bool ignition, bool usb_enum, bool heartbeat_seen);
 
@@ -36,7 +35,6 @@ struct board {
   board_set_ir_power set_ir_power;
   board_set_fan_enabled set_fan_enabled;
   board_set_phone_power set_phone_power;
-  board_set_clock_source_mode set_clock_source_mode;
   board_set_siren set_siren;
   board_board_tick board_tick;
 };
diff --git a/board/boards/dos.h b/board/boards/dos.h
index 630a3095..1a018797 100644
--- a/board/boards/dos.h
+++ b/board/boards/dos.h
@@ -110,10 +110,6 @@ void dos_set_fan_enabled(bool enabled){
   set_gpio_output(GPIOA, 1, enabled);
 }
 
-void dos_set_clock_source_mode(uint8_t mode){
-  clock_source_init(mode);
-}
-
 void dos_set_siren(bool enabled){
   set_gpio_output(GPIOC, 12, enabled);
 }
@@ -186,7 +182,7 @@ void dos_init(void) {
   }
 
   // Init clock source (camera strobe) using PWM
-  dos_set_clock_source_mode(CLOCK_SOURCE_MODE_PWM);
+  clock_source_init();
 }
 
 const harness_configuration dos_harness_config = {
@@ -230,6 +226,5 @@ const board board_dos = {
   .set_fan_enabled = dos_set_fan_enabled,
   .set_ir_power = dos_set_ir_power,
   .set_phone_power = unused_set_phone_power,
-  .set_clock_source_mode = dos_set_clock_source_mode,
   .set_siren = dos_set_siren
 };
diff --git a/board/boards/grey.h b/board/boards/grey.h
index 94d66bf9..1129eba4 100644
--- a/board/boards/grey.h
+++ b/board/boards/grey.h
@@ -56,6 +56,5 @@ const board board_grey = {
   .set_fan_enabled = unused_set_fan_enabled,
   .set_ir_power = unused_set_ir_power,
   .set_phone_power = unused_set_phone_power,
-  .set_clock_source_mode = unused_set_clock_source_mode,
   .set_siren = unused_set_siren
 };
diff --git a/board/boards/pedal.h b/board/boards/pedal.h
index fe9a8ff4..6e548783 100644
--- a/board/boards/pedal.h
+++ b/board/boards/pedal.h
@@ -94,6 +94,5 @@ const board board_pedal = {
   .set_fan_enabled = unused_set_fan_enabled,
   .set_ir_power = unused_set_ir_power,
   .set_phone_power = unused_set_phone_power,
-  .set_clock_source_mode = unused_set_clock_source_mode,
   .set_siren = unused_set_siren
 };
diff --git a/board/boards/red.h b/board/boards/red.h
index 76f06faa..1e33aee0 100644
--- a/board/boards/red.h
+++ b/board/boards/red.h
@@ -194,6 +194,5 @@ const board board_red = {
   .set_fan_enabled = unused_set_fan_enabled,
   .set_ir_power = unused_set_ir_power,
   .set_phone_power = unused_set_phone_power,
-  .set_clock_source_mode = unused_set_clock_source_mode,
   .set_siren = unused_set_siren
 };
diff --git a/board/boards/red_v2.h b/board/boards/red_v2.h
index 8527432e..5b613358 100644
--- a/board/boards/red_v2.h
+++ b/board/boards/red_v2.h
@@ -25,6 +25,5 @@ const board board_red_v2 = {
   .set_fan_enabled = unused_set_fan_enabled,
   .set_ir_power = unused_set_ir_power,
   .set_phone_power = unused_set_phone_power,
-  .set_clock_source_mode = unused_set_clock_source_mode,
   .set_siren = unused_set_siren
 };
diff --git a/board/boards/tres.h b/board/boards/tres.h
index 095783a8..7073cecf 100644
--- a/board/boards/tres.h
+++ b/board/boards/tres.h
@@ -41,6 +41,5 @@ const board board_tres = {
   .set_fan_enabled = unused_set_fan_enabled,
   .set_ir_power = unused_set_ir_power,
   .set_phone_power = unused_set_phone_power,
-  .set_clock_source_mode = unused_set_clock_source_mode,
   .set_siren = unused_set_siren
 };
diff --git a/board/boards/uno.h b/board/boards/uno.h
index d4461b49..b2762b06 100644
--- a/board/boards/uno.h
+++ b/board/boards/uno.h
@@ -266,6 +266,5 @@ const board board_uno = {
   .set_fan_enabled = uno_set_fan_enabled,
   .set_ir_power = uno_set_ir_power,
   .set_phone_power = uno_set_phone_power,
-  .set_clock_source_mode = unused_set_clock_source_mode,
   .set_siren = unused_set_siren
 };
diff --git a/board/boards/unused_funcs.h b/board/boards/unused_funcs.h
index be675d89..dd8dcec5 100644
--- a/board/boards/unused_funcs.h
+++ b/board/boards/unused_funcs.h
@@ -14,10 +14,6 @@ void unused_set_phone_power(bool enabled) {
   UNUSED(enabled);
 }
 
-void unused_set_clock_source_mode(uint8_t mode) {
-  UNUSED(mode);
-}
-
 void unused_set_siren(bool enabled) {
   UNUSED(enabled);
 }
diff --git a/board/boards/white.h b/board/boards/white.h
index 15335494..fc5c23ba 100644
--- a/board/boards/white.h
+++ b/board/boards/white.h
@@ -258,6 +258,5 @@ const board board_white = {
   .set_fan_enabled = unused_set_fan_enabled,
   .set_ir_power = unused_set_ir_power,
   .set_phone_power = unused_set_phone_power,
-  .set_clock_source_mode = unused_set_clock_source_mode,
   .set_siren = unused_set_siren
 };
diff --git a/board/main_comms.h b/board/main_comms.h
index 3c41596c..29ad3a64 100644
--- a/board/main_comms.h
+++ b/board/main_comms.h
@@ -525,10 +525,6 @@ int comms_control_handler(ControlPacket_t *req, uint8_t *resp) {
         }
       }
       break;
-    // **** 0xf5: set clock source mode
-    case 0xf5:
-      current_board->set_clock_source_mode(req->param1);
-      break;
     // **** 0xf6: set siren enabled
     case 0xf6:
       siren_enabled = (req->param1 != 0U);
diff --git a/board/stm32fx/clock_source.h b/board/stm32fx/clock_source.h
index f8fea5fc..03db711f 100644
--- a/board/stm32fx/clock_source.h
+++ b/board/stm32fx/clock_source.h
@@ -1,98 +1,19 @@
+void clock_source_init(void) {
+  // No interrupts
+  NVIC_DisableIRQ(TIM1_UP_TIM10_IRQn);
+  NVIC_DisableIRQ(TIM1_CC_IRQn);
 
-#define CLOCK_SOURCE_MODE_DISABLED       0U
-#define CLOCK_SOURCE_MODE_FREE_RUNNING   1U
-#define CLOCK_SOURCE_MODE_PWM            2U
+  // Set GPIO as timer channels
+  set_gpio_alternate(GPIOB, 14, GPIO_AF1_TIM1);
+  set_gpio_alternate(GPIOB, 15, GPIO_AF1_TIM1);
 
-#define CLOCK_SOURCE_PERIOD_MS           50U
-#define CLOCK_SOURCE_PULSE_LEN_MS        2U
+  // Set PWM mode
+  register_set(&(TIM1->CCMR1), (0b110 << TIM_CCMR1_OC2M_Pos), 0xFFFFU);
+  register_set(&(TIM1->CCMR2), (0b110 << TIM_CCMR2_OC3M_Pos), 0xFFFFU);
 
-uint8_t clock_source_mode = CLOCK_SOURCE_MODE_DISABLED;
+  // Enable output
+  register_set(&(TIM1->BDTR), TIM_BDTR_MOE, 0xFFFFU);
 
-void TIM1_UP_TIM10_IRQ_Handler(void) {
-  if((TIM1->SR & TIM_SR_UIF) != 0) {
-    if(clock_source_mode == CLOCK_SOURCE_MODE_FREE_RUNNING) {
-      // Start clock pulse
-      set_gpio_output(GPIOB, 14, true);
-      set_gpio_output(GPIOB, 15, true);
-      set_gpio_output(GPIOC, 5, true);
-    }
-
-    // Reset interrupt
-    TIM1->SR &= ~(TIM_SR_UIF);
-  }
-}
-
-void TIM1_CC_IRQ_Handler(void) {
-  if((TIM1->SR & TIM_SR_CC1IF) != 0) {
-    if(clock_source_mode == CLOCK_SOURCE_MODE_FREE_RUNNING) {
-      // End clock pulse
-      set_gpio_output(GPIOB, 14, false);
-      set_gpio_output(GPIOB, 15, false);
-      set_gpio_output(GPIOC, 5, false);
-    }
-
-    // Reset interrupt
-    TIM1->SR &= ~(TIM_SR_CC1IF);
-  }
-}
-
-void clock_source_init(uint8_t mode){
-  // Setup timer
-  REGISTER_INTERRUPT(TIM1_UP_TIM10_IRQn, TIM1_UP_TIM10_IRQ_Handler, (1200U / CLOCK_SOURCE_PERIOD_MS) , FAULT_INTERRUPT_RATE_TIM1)
-  REGISTER_INTERRUPT(TIM1_CC_IRQn, TIM1_CC_IRQ_Handler, (1200U / CLOCK_SOURCE_PERIOD_MS) , FAULT_INTERRUPT_RATE_TIM1)
-  register_set(&(TIM1->PSC), ((APB2_FREQ*100U)-1U), 0xFFFFU);                 // Tick on 0.1 ms
-  register_set(&(TIM1->ARR), ((CLOCK_SOURCE_PERIOD_MS*10U) - 1U), 0xFFFFU);   // Period
-  register_set(&(TIM1->CCMR1), 0U, 0xFFFFU);                                  // No output on compare
-  register_set(&(TIM1->CCER), TIM_CCER_CC1E, 0xFFFFU);                        // Enable compare 1
-  register_set(&(TIM1->CCR1), (CLOCK_SOURCE_PULSE_LEN_MS*10U), 0xFFFFU);      // Compare 1 value
-  register_set(&(TIM1->CCR2), (CLOCK_SOURCE_PULSE_LEN_MS*10U), 0xFFFFU);      // Compare 1 value
-  register_set(&(TIM1->CCR3), (CLOCK_SOURCE_PULSE_LEN_MS*10U), 0xFFFFU);      // Compare 1 value
-  register_set_bits(&(TIM1->DIER), TIM_DIER_UIE | TIM_DIER_CC1IE);            // Enable interrupts
-  register_set(&(TIM1->CR1), TIM_CR1_CEN, 0x3FU);                             // Enable timer
-
-  // Set mode
-  switch(mode) {
-    case CLOCK_SOURCE_MODE_DISABLED:
-      // No clock signal
-      NVIC_DisableIRQ(TIM1_UP_TIM10_IRQn);
-      NVIC_DisableIRQ(TIM1_CC_IRQn);
-
-      // Disable pulse if we were in the middle of it
-      set_gpio_output(GPIOB, 14, false);
-      set_gpio_output(GPIOB, 15, false);
-
-      clock_source_mode = CLOCK_SOURCE_MODE_DISABLED;
-      break;
-    case CLOCK_SOURCE_MODE_FREE_RUNNING:
-      // Clock signal is based on internal timer
-      NVIC_EnableIRQ(TIM1_UP_TIM10_IRQn);
-      NVIC_EnableIRQ(TIM1_CC_IRQn);
-
-      clock_source_mode = CLOCK_SOURCE_MODE_FREE_RUNNING;
-      break;
-    case CLOCK_SOURCE_MODE_PWM:
-      // No interrupts
-      NVIC_DisableIRQ(TIM1_UP_TIM10_IRQn);
-      NVIC_DisableIRQ(TIM1_CC_IRQn);
-
-      // Set GPIO as timer channels
-      set_gpio_alternate(GPIOB, 14, GPIO_AF1_TIM1);
-      set_gpio_alternate(GPIOB, 15, GPIO_AF1_TIM1);
-
-      // Set PWM mode
-      register_set(&(TIM1->CCMR1), (0b110 << TIM_CCMR1_OC2M_Pos), 0xFFFFU);
-      register_set(&(TIM1->CCMR2), (0b110 << TIM_CCMR2_OC3M_Pos), 0xFFFFU);
-
-      // Enable output
-      register_set(&(TIM1->BDTR), TIM_BDTR_MOE, 0xFFFFU);
-
-      // Enable complementary compares
-      register_set_bits(&(TIM1->CCER), TIM_CCER_CC2NE | TIM_CCER_CC3NE);
-
-      clock_source_mode = CLOCK_SOURCE_MODE_PWM;
-      break;
-    default:
-      puts("Unknown clock source mode: "); puth(mode); puts("\n");
-      break;
-  }
+  // Enable complementary compares
+  register_set_bits(&(TIM1->CCER), TIM_CCER_CC2NE | TIM_CCER_CC3NE);
 }
diff --git a/python/__init__.py b/python/__init__.py
index 98b2c4a2..ea25a4d9 100644
--- a/python/__init__.py
+++ b/python/__init__.py
@@ -205,9 +205,6 @@ class Panda:
   INTERNAL_DEVICES = (HW_TYPE_UNO, HW_TYPE_DOS)
   HAS_OBD = (HW_TYPE_BLACK_PANDA, HW_TYPE_UNO, HW_TYPE_DOS, HW_TYPE_RED_PANDA, HW_TYPE_RED_PANDA_V2, HW_TYPE_TRES)
 
-  CLOCK_SOURCE_MODE_DISABLED = 0
-  CLOCK_SOURCE_MODE_FREE_RUNNING = 1
-
   # first byte is for EPS scaling factor
   FLAG_TOYOTA_ALT_BRAKE = (1 << 8)
   FLAG_TOYOTA_STOCK_LONGITUDINAL = (2 << 8)
@@ -846,10 +843,6 @@ class Panda:
   def set_phone_power(self, enabled):
     self._handle.controlWrite(Panda.REQUEST_OUT, 0xb3, int(enabled), 0, b'')
 
-  # ************** Clock Source **************
-  def set_clock_source_mode(self, mode):
-    self._handle.controlWrite(Panda.REQUEST_OUT, 0xf5, int(mode), 0, b'')
-
   # ****************** Siren *****************
   def set_siren(self, enabled):
     self._handle.controlWrite(Panda.REQUEST_OUT, 0xf6, int(enabled), 0, b'')