From: Adam Ford <aford173@xxxxxxxxx> commit 4ce01ce36d77137cf60776b320babed89de6bd4c upstream. There is a header for a DB9 serial port, but any attempts to use hardware handshaking fail. Enable RTS and CTS pin muxing and enable handshaking in the uart node. Signed-off-by: Adam Ford <aford173@xxxxxxxxx> Signed-off-by: Shawn Guo <shawnguo@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/arm64/boot/dts/freescale/imx8mm-beacon-baseboard.dtsi | 3 +++ 1 file changed, 3 insertions(+) --- a/arch/arm64/boot/dts/freescale/imx8mm-beacon-baseboard.dtsi +++ b/arch/arm64/boot/dts/freescale/imx8mm-beacon-baseboard.dtsi @@ -167,6 +167,7 @@ pinctrl-0 = <&pinctrl_uart3>; assigned-clocks = <&clk IMX8MM_CLK_UART3>; assigned-clock-parents = <&clk IMX8MM_SYS_PLL1_80M>; + uart-has-rtscts; status = "okay"; }; @@ -237,6 +238,8 @@ fsl,pins = < MX8MM_IOMUXC_ECSPI1_SCLK_UART3_DCE_RX 0x40 MX8MM_IOMUXC_ECSPI1_MOSI_UART3_DCE_TX 0x40 + MX8MM_IOMUXC_ECSPI1_MISO_UART3_DCE_CTS_B 0x40 + MX8MM_IOMUXC_ECSPI1_SS0_UART3_DCE_RTS_B 0x40 >; };