Function uart_rx_enable 

pub unsafe extern "C" fn uart_rx_enable(
    dev: *const device,
    buf: *mut u8,
    len: usize,
    timeout: i32,
) -> c_int

@brief Start receiving data through UART.

Function sets given buffer as first buffer for receiving and returns immediately. After that event handler, set using @ref uart_callback_set, is called with #UART_RX_RDY or #UART_RX_BUF_REQUEST events.

@param dev UART device instance. @param buf Pointer to receive buffer. @param len Buffer length. @param timeout Inactivity period after receiving at least a byte which triggers #UART_RX_RDY event. Given in microseconds. @ref SYS_FOREVER_US disables timeout. See @ref uart_event_type for details.

@return 0 on success, negative errno value on failure. @retval -ENOTSUP API is not enabled. @retval -EBUSY RX already in progress.