1 // SPDX-License-Identifier: (GPL-2.0+ OR MIT)
2 /*
3 * Copyright 2022 Gateworks Corporation
4 *
5 * GW72xx RS232 with RTS/CTS hardware flow control:
6 * - GPIO4_0 rs485_en needs to be driven low (in-active)
7 * - UART4_TX becomes RTS
8 * - UART4_RX becomes CTS
9 */
10
11 #include <dt-bindings/gpio/gpio.h>
12
13 #include "imx8mm-pinfunc.h"
14
15 /dts-v1/;
16 /plugin/;
17
18 &{/} {
19 compatible = "gw,imx8mm-gw72xx-0x";
20 };
21
22 &gpio4 {
23 rs485_en {
24 gpio-hog;
25 gpios = <0 GPIO_ACTIVE_HIGH>;
26 output-low;
27 line-name = "rs485_en";
28 };
29 };
30
31 &uart2 {
32 pinctrl-names = "default";
33 pinctrl-0 = <&pinctrl_uart2>;
34 rts-gpios = <&gpio5 29 GPIO_ACTIVE_LOW>;
35 cts-gpios = <&gpio5 28 GPIO_ACTIVE_LOW>;
36 status = "okay";
37 };
38
39 &uart4 {
40 status = "disabled";
41 };
42
43 &iomuxc {
44 pinctrl_uart2: uart2grp {
45 fsl,pins = <
46 MX8MM_IOMUXC_UART2_RXD_UART2_DCE_RX 0x140
47 MX8MM_IOMUXC_UART2_TXD_UART2_DCE_TX 0x140
48 MX8MM_IOMUXC_UART4_TXD_GPIO5_IO29 0x140
49 MX8MM_IOMUXC_UART4_RXD_GPIO5_IO28 0x140
50 >;
51 };
52 };
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