Fix FDCan Stuff (#392)

Co-authored-by: Caio DaSilva <dasilva.cai@northeastern.edu>

Author: bjackson312006

platforms/stm32h563/include/fdcan.h

@@ -28,6 +28,8 @@ HAL_StatusTypeDef can_init(can_t *can, FDCAN_HandleTypeDef *hcan);
 HAL_StatusTypeDef can_send_msg(can_t *can, can_msg_t *msg);
 HAL_StatusTypeDef can_add_filter_standard(can_t *can, uint16_t can_ids[2]);
 HAL_StatusTypeDef can_add_filter_extended(can_t *can, uint32_t can_ids[2]);
+bool              can_is_bus_off(can_t *can);
+HAL_StatusTypeDef can_recover_bus_off(can_t *can);
 
 // clang-format on
 #endif // FDCAN_H

platforms/stm32h563/src/fdcan.c

@@ -13,19 +13,31 @@ HAL_StatusTypeDef can_init(can_t *can, FDCAN_HandleTypeDef *hcan)
 	can->extended_filter_index = 0;
 	can->hcan = hcan;
 
-	/* Config interrupts */
+	/* Config incoming message interrupt. */
 	HAL_StatusTypeDef status = HAL_FDCAN_ConfigInterruptLines(can->hcan, FDCAN_IT_RX_FIFO0_NEW_MESSAGE, FDCAN_INTERRUPT_LINE0);
 	if (status != HAL_OK)
 	{
-		printf("[fdcan.c/can_init()] ERROR: Failed to run HAL_FDCAN_ConfigInterruptLines() (Status: %d).\n", status);
+		printf("[fdcan.c/can_init()] ERROR: Failed to run HAL_FDCAN_ConfigInterruptLines(can->hcan, FDCAN_IT_RX_FIFO0_NEW_MESSAGE, FDCAN_INTERRUPT_LINE0); (Status: %d).\n", status);
 		return status;
 	}
-
-	/* Activate interrupt notifications */
 	status = HAL_FDCAN_ActivateNotification(can->hcan, FDCAN_IT_RX_FIFO0_NEW_MESSAGE, 0);
 	if (status != HAL_OK)
 	{
-		printf("[fdcan.c/can_init()] ERROR: Failed to run HAL_FDCAN_ActivateNotification() (Status: %d).\n", status);
+		printf("[fdcan.c/can_init()] ERROR: Failed to run HAL_FDCAN_ActivateNotification(can->hcan, FDCAN_IT_RX_FIFO0_NEW_MESSAGE, 0); (Status: %d).\n", status);
+		return status;
+	}
+
+	/* Config BusOff interrupt. */
+	status = HAL_FDCAN_ConfigInterruptLines(can->hcan, FDCAN_IT_BUS_OFF, FDCAN_INTERRUPT_LINE1);
+	if (status != HAL_OK)
+	{
+		printf("[fdcan.c/can_init()] ERROR: Failed to run HAL_FDCAN_ConfigInterruptLines(can->hcan, FDCAN_IT_BUS_OFF, FDCAN_INTERRUPT_LINE1); (Status: %d).\n", status);
+		return status;
+	}
+	status = HAL_FDCAN_ActivateNotification(can->hcan, FDCAN_IT_BUS_OFF, 1);
+	if (status != HAL_OK)
+	{
+		printf("[fdcan.c/can_init()] ERROR: Failed to run HAL_FDCAN_ActivateNotification(can->hcan, FDCAN_IT_BUS_OFF, 1); (Status: %d).\n", status);
 		return status;
 	}
 
@@ -101,6 +113,36 @@ HAL_StatusTypeDef can_add_filter_extended(can_t *can, uint32_t can_ids[2])
 	return status;
 }
 
+/* Returns true if the CAN node is in bus-off state. */
+bool can_is_bus_off(can_t *can) {
+	FDCAN_ProtocolStatusTypeDef status;
+	HAL_FDCAN_GetProtocolStatus(can->hcan, &status);
+	return (bool)status.BusOff;
+}
+
+/* Recovers from bus-off by stopping and restarting the FDCAN peripheral.
+   Filters survive Stop/Start but notifications do not, so RX FIFO interrupt is re-enabled. */
+HAL_StatusTypeDef can_recover_bus_off(can_t *can) {
+	HAL_StatusTypeDef status = HAL_FDCAN_Stop(can->hcan);
+	if (status != HAL_OK) {
+		printf("[fdcan.c/can_recover_bus_off()] ERROR: HAL_FDCAN_Stop() failed (Status: %d).\n", status);
+		return status;
+	}
+
+	status = HAL_FDCAN_Start(can->hcan);
+	if (status != HAL_OK) {
+		printf("[fdcan.c/can_recover_bus_off()] ERROR: HAL_FDCAN_Start() failed (Status: %d).\n", status);
+		return status;
+	}
+
+	status = HAL_FDCAN_ActivateNotification(can->hcan, FDCAN_IT_RX_FIFO0_NEW_MESSAGE, 0);
+	if (status != HAL_OK) {
+		printf("[fdcan.c/can_recover_bus_off()] ERROR: HAL_FDCAN_ActivateNotification() failed (Status: %d).\n", status);
+	}
+
+	return status;
+}
+
 /* Sends a CAN message. */
 HAL_StatusTypeDef can_send_msg(can_t *can, can_msg_t *msg)
 {