// SPDX-License-Identifier: (GPL-2.0+ OR MIT) /* * Copyright 2021 Gateworks Corporation * * GW73xx RS422 (RS485 full duplex): * - GPIO1_0 rs485_term selects on-chip termination * - GPIO4_0 rs485_en needs to be driven high (active) * - GPIO4_2 rs485_hd needs to be driven low (in-active) * - UART4_TX is DE for RS485 transmitter * - RS485_EN needs to be pulled high * - RS485_HALF needs to be low */ #include #include "imx8mm-pinfunc.h" /dts-v1/; /plugin/; &{/} { compatible = "gw,imx8mm-gw73xx-0x"; }; &gpio4 { rs485_en { gpio-hog; gpios = <0 GPIO_ACTIVE_HIGH>; output-high; line-name = "rs485_en"; }; rs485_hd { gpio-hog; gpios = <2 GPIO_ACTIVE_HIGH>; output-low; line-name = "rs485_hd"; }; }; &uart2 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_uart2>; rts-gpios = <&gpio5 29 GPIO_ACTIVE_HIGH>; linux,rs485-enabled-at-boot-time; status = "okay"; }; &uart4 { status = "disabled"; }; &iomuxc { pinctrl_uart2: uart2grp { fsl,pins = < MX8MM_IOMUXC_UART2_RXD_UART2_DCE_RX 0x140 MX8MM_IOMUXC_UART2_TXD_UART2_DCE_TX 0x140 MX8MM_IOMUXC_UART4_TXD_GPIO5_IO29 0x140 >; }; };