1// SPDX-License-Identifier: (GPL-2.0+ OR MIT) 2/* 3 * Copyright 2021 Gateworks Corporation 4 * 5 * GW73xx RS422 (RS485 full duplex): 6 * - GPIO1_0 rs485_term selects on-chip termination 7 * - GPIO4_0 rs485_en needs to be driven high (active) 8 * - GPIO4_2 rs485_hd needs to be driven low (in-active) 9 * - UART4_TX is DE for RS485 transmitter 10 * - RS485_EN needs to be pulled high 11 * - RS485_HALF needs to be low 12 */ 13 14#include <dt-bindings/gpio/gpio.h> 15 16#include "imx8mm-pinfunc.h" 17 18/dts-v1/; 19/plugin/; 20 21&{/} { 22 compatible = "gw,imx8mm-gw73xx-0x"; 23}; 24 25&gpio4 { 26 rs485_en { 27 gpio-hog; 28 gpios = <0 GPIO_ACTIVE_HIGH>; 29 output-high; 30 line-name = "rs485_en"; 31 }; 32 33 rs485_hd { 34 gpio-hog; 35 gpios = <2 GPIO_ACTIVE_HIGH>; 36 output-low; 37 line-name = "rs485_hd"; 38 }; 39}; 40 41&uart2 { 42 pinctrl-names = "default"; 43 pinctrl-0 = <&pinctrl_uart2>; 44 rts-gpios = <&gpio5 29 GPIO_ACTIVE_HIGH>; 45 linux,rs485-enabled-at-boot-time; 46 status = "okay"; 47}; 48 49&uart4 { 50 status = "disabled"; 51}; 52 53&iomuxc { 54 pinctrl_uart2: uart2grp { 55 fsl,pins = < 56 MX8MM_IOMUXC_UART2_RXD_UART2_DCE_RX 0x140 57 MX8MM_IOMUXC_UART2_TXD_UART2_DCE_TX 0x140 58 MX8MM_IOMUXC_UART4_TXD_GPIO5_IO29 0x140 59 >; 60 }; 61}; 62