diff --git a/include/libopencm3/stm32/can.h b/include/libopencm3/stm32/can.h
index 1855c15b..7983b84c 100644
--- a/include/libopencm3/stm32/can.h
+++ b/include/libopencm3/stm32/can.h
@@ -668,12 +668,13 @@ void can_disable_irq(uint32_t canport, uint32_t irq);
 
 int can_transmit(uint32_t canport, uint32_t id, bool ext, bool rtr,
 		 uint8_t length, uint8_t *data);
-void can_receive(uint32_t canport, uint8_t fifo, bool release, uint32_t *id,
+uint32_t can_receive(uint32_t canport, uint8_t fifo, bool release, uint32_t *id,
 		 bool *ext, bool *rtr, uint8_t *fmi, uint8_t *length,
 		 uint8_t *data, uint16_t *timestamp);
 
 void can_fifo_release(uint32_t canport, uint8_t fifo);
 bool can_available_mailbox(uint32_t canport);
+uint32_t can_fifo_pending(uint32_t canport, uint8_t fifo);
 END_DECLS
 
 /**@}*/
diff --git a/include/libopencm3/stm32/common/adc_common_v1.h b/include/libopencm3/stm32/common/adc_common_v1.h
index 29ff0d0b..6d0752fe 100644
--- a/include/libopencm3/stm32/common/adc_common_v1.h
+++ b/include/libopencm3/stm32/common/adc_common_v1.h
@@ -399,7 +399,7 @@ void adc_set_right_aligned(uint32_t adc);
 bool adc_eoc(uint32_t adc);
 bool adc_eoc_injected(uint32_t adc);
 uint32_t adc_read_regular(uint32_t adc);
-uint32_t adc_read_injected(uint32_t adc, uint8_t reg);
+int32_t adc_read_injected(uint32_t adc, uint8_t reg);
 void adc_set_continuous_conversion_mode(uint32_t adc);
 void adc_set_single_conversion_mode(uint32_t adc);
 void adc_set_regular_sequence(uint32_t adc, uint8_t length, uint8_t channel[]);
diff --git a/lib/stm32/can.c b/lib/stm32/can.c
index f404a4a7..9941e7a3 100644
--- a/lib/stm32/can.c
+++ b/lib/stm32/can.c
@@ -466,11 +466,15 @@ void can_fifo_release(uint32_t canport, uint8_t fifo)
 @param[out] data Unsigned int8[]. Message payload data.
 @param[out] timestamp Pointer to store the message timestamp.
 			Only valid on time triggered CAN. Use NULL to ignore.
+@returns int 0-3 depending on how many messages where pending before
+			releasing the FIFO.
+			when 0 is returned no message could be retrieved
  */
-void can_receive(uint32_t canport, uint8_t fifo, bool release, uint32_t *id,
+uint32_t can_receive(uint32_t canport, uint8_t fifo, bool release, uint32_t *id,
 		 bool *ext, bool *rtr, uint8_t *fmi, uint8_t *length,
 		 uint8_t *data, uint16_t *timestamp)
 {
+	uint32_t pending_cnt = can_fifo_pending(canport, fifo);
 	uint32_t fifo_id = 0;
 	union {
 		uint8_t data8[4];
@@ -542,9 +546,28 @@ void can_receive(uint32_t canport, uint8_t fifo, bool release, uint32_t *id,
 	if (release) {
 		can_fifo_release(canport, fifo);
 	}
+
+	return pending_cnt;
 }
 
 bool can_available_mailbox(uint32_t canport)
 {
 	return CAN_TSR(canport) & (CAN_TSR_TME0 | CAN_TSR_TME1 | CAN_TSR_TME2);
 }
+
+/*---------------------------------------------------------------------------*/
+/** @brief CAN get number of pending RX messages
+
+@param[in] canport Unsigned int32. CAN block register base @ref can_reg_base.
+@param[in] fifo Unsigned int8. FIFO id.
+@returns int 1, 2 or 3 if messages are pending in given fifo, 0 otherwise.
+ */
+uint32_t can_fifo_pending(uint32_t canport, uint8_t fifo)
+{
+	if (fifo == 0) {
+		return CAN_RF0R(canport) & CAN_RF0R_FMP0_MASK;
+	} else {
+		return CAN_RF1R(canport) & CAN_RF1R_FMP1_MASK;
+	}
+}
+
diff --git a/lib/stm32/common/adc_common_v1.c b/lib/stm32/common/adc_common_v1.c
index 227855d0..1edceb7a 100644
--- a/lib/stm32/common/adc_common_v1.c
+++ b/lib/stm32/common/adc_common_v1.c
@@ -480,17 +480,17 @@ adc_set_injected_offset.
 @returns Unsigned int32 conversion result.
 */
 
-uint32_t adc_read_injected(uint32_t adc, uint8_t reg)
+int32_t adc_read_injected(uint32_t adc, uint8_t reg)
 {
 	switch (reg) {
 	case 1:
-		return ADC_JDR1(adc);
+		return (int16_t)ADC_JDR1(adc);
 	case 2:
-		return ADC_JDR2(adc);
+		return (int16_t)ADC_JDR2(adc);
 	case 3:
-		return ADC_JDR3(adc);
+		return (int16_t)ADC_JDR3(adc);
 	case 4:
-		return ADC_JDR4(adc);
+		return (int16_t)ADC_JDR4(adc);
 	}
 	return 0;
 }