PCH_UART_FCR_TFR
#define PCH_UART_HAL_CLR_TX_FIFO (PCH_UART_FCR_TFR)
if (flag & ~(PCH_UART_FCR_TFR | PCH_UART_FCR_RFR)) {
dmamode | fifo_size | trigger | PCH_UART_FCR_RFR | PCH_UART_FCR_TFR;
iowrite8(PCH_UART_FCR_FIFOE | PCH_UART_FCR_RFR | PCH_UART_FCR_TFR,