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 termi
7 * - GPIO4_0 rs485_en needs to be driven high
8 * - GPIO4_2 rs485_hd needs to be driven low
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-hog {
27 gpio-hog;
28 gpios = <0 GPIO_ACTIVE_HIGH>;
29 output-high;
30 line-name = "rs485_en";
31 };
32
33 rs485-hd-hog {
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_HIG
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
57 MX8MM_IOMUXC_UART2_TXD
58 MX8MM_IOMUXC_UART4_TXD
59 >;
60 };
61 };
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