From 4252ede53d46e945b07ea370aca07e2b3e44726e Mon Sep 17 00:00:00 2001 From: Ahmad Fatoum Date: Mon, 6 Jan 2025 17:06:42 +0100 Subject: [PATCH] arm64: dts: imx8mp-skov: configure uart1 for RS485 uart1 TX, RX and RTS signals go off the base board and to a RS485 transceiver. Describe this in the device tree. Signed-off-by: Ahmad Fatoum Signed-off-by: Shawn Guo --- arch/arm64/boot/dts/freescale/imx8mp-skov-reva.dtsi | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/arm64/boot/dts/freescale/imx8mp-skov-reva.dtsi b/arch/arm64/boot/dts/freescale/imx8mp-skov-reva.dtsi index 7ae686d37ddac..bce23d62cd277 100644 --- a/arch/arm64/boot/dts/freescale/imx8mp-skov-reva.dtsi +++ b/arch/arm64/boot/dts/freescale/imx8mp-skov-reva.dtsi @@ -404,6 +404,13 @@ pinctrl-names = "default"; pinctrl-0 = <&pinctrl_uart1>; status = "okay"; + /* + * While there is no CTS line, the property "uart-has-rtscts" is still + * the right thing to do to enable the UART to do RS485. In RS485-Mode + * CTS isn't used anyhow and there is no dedicated property + * "uart-has-rts-but-no-cts". + */ + uart-has-rtscts; }; &uart2 { @@ -618,6 +625,8 @@ MX8MP_IOMUXC_UART1_RXD__UART1_DCE_RX 0x140 MX8MP_IOMUXC_UART1_TXD__UART1_DCE_TX 0x140 MX8MP_IOMUXC_UART3_RXD__UART1_DTE_RTS 0x140 + /* CTS pin is not connected, but needed as workaround */ + MX8MP_IOMUXC_UART3_TXD__UART1_DTE_CTS 0x140 >; }; -- 2.47.2