0001 // SPDX-License-Identifier: (GPL-2.0+ OR MIT)
0002 /*
0003 * Copyright 2022 Gateworks Corporation
0004 *
0005 * GW72xx RS422 (RS485 full duplex):
0006 * - GPIO1_0 rs485_term selects on-chip termination
0007 * - GPIO4_0 rs485_en needs to be driven high (active)
0008 * - GPIO4_2 rs485_hd needs to be driven low (in-active)
0009 * - UART4_TX is DE for RS485 transmitter
0010 * - RS485_EN needs to be pulled high
0011 * - RS485_HALF needs to be low
0012 */
0013
0014 #include <dt-bindings/gpio/gpio.h>
0015
0016 #include "imx8mm-pinfunc.h"
0017
0018 /dts-v1/;
0019 /plugin/;
0020
0021 &{/} {
0022 compatible = "gw,imx8mm-gw72xx-0x";
0023 };
0024
0025 &gpio4 {
0026 rs485_en {
0027 gpio-hog;
0028 gpios = <0 GPIO_ACTIVE_HIGH>;
0029 output-high;
0030 line-name = "rs485_en";
0031 };
0032
0033 rs485_hd {
0034 gpio-hog;
0035 gpios = <2 GPIO_ACTIVE_HIGH>;
0036 output-low;
0037 line-name = "rs485_hd";
0038 };
0039 };
0040
0041 &uart2 {
0042 pinctrl-names = "default";
0043 pinctrl-0 = <&pinctrl_uart2>;
0044 rts-gpios = <&gpio5 29 GPIO_ACTIVE_HIGH>;
0045 linux,rs485-enabled-at-boot-time;
0046 status = "okay";
0047 };
0048
0049 &uart4 {
0050 status = "disabled";
0051 };
0052
0053 &iomuxc {
0054 pinctrl_uart2: uart2grp {
0055 fsl,pins = <
0056 MX8MM_IOMUXC_UART2_RXD_UART2_DCE_RX 0x140
0057 MX8MM_IOMUXC_UART2_TXD_UART2_DCE_TX 0x140
0058 MX8MM_IOMUXC_UART4_TXD_GPIO5_IO29 0x140
0059 >;
0060 };
0061 };
