Start onewire interface. But probably won't finish it

stm-firmware/include/stm-periph/dma-ring-buffer.h

@@ -96,6 +96,14 @@ int dma_ring_buffer_periph_to_mem_get_data(struct dma_ring_buffer_to_mem *buff,
  */
 void dma_ring_buffer_periph_to_mem_stop(struct dma_ring_buffer_to_mem *buff);
 
+/**
+ * @brief Get fill level of peripheral to memory DMA ring buffer
+ * @param buff Buffer
+ * @param fill_level fill level to write data to
+ * @return 0 if success
+ */
+int dma_ring_buffer_periph_to_mem_fill_level(struct dma_ring_buffer_to_mem *buff, size_t *fill_level);
+
 /**
  * @brief Initialize ring buffer to streaming data from meory to a peripheral
  * @param[in,out] dma_buffer DMA ring buffer structure
@@ -138,6 +146,14 @@ void dma_ring_buffer_mem_to_periph_int_callback(struct dma_ring_buffer_to_periph
  */
 void dma_ring_buffer_mem_to_periph_stop(struct dma_ring_buffer_to_periph *buff);
 
+/**
+ * @brief Get fill level of mem to periph DMA ring buffer
+ * @param buff Buffer
+ * @param fill_level fill level to write data to
+ * @return 0 if success
+ */
+int dma_ring_buffer_mem_to_periph_fill_level(struct dma_ring_buffer_to_periph *buff, size_t *fill_level);
+
 /** @} */
 
 #endif /* __DMA_RING_BUFFER_H__ */

stm-firmware/include/stm-periph/uart.h

@@ -70,5 +70,8 @@ int uart_check_rx_avail(struct stm_uart *uart);
 
 void uart_tx_dma_complete_int_callback(struct stm_uart *uart);
 
+size_t uart_dma_tx_queue_avail(struct stm_uart *uart);
+
+size_t uart_dma_rx_queue_avail(struct stm_uart *uart);
 
 #endif /* UART_UART_H_ */