From 5963d97aa780619ffb66cf4886c0ca1175ccbd3e Mon Sep 17 00:00:00 2001 From: Farouk Bouabid Date: Thu, 8 Feb 2024 16:39:56 +0100 Subject: [PATCH] arm64: dts: rockchip: add rs485 support on uart5 of px30-ringneck-haikou A hardware switch can set the rs485 transceiver into half or full duplex mode. Switching to the half-duplex mode requires the user to enable em485 on uart5 using ioctl, DE/RE are both connected to GPIO0_B5 which is the RTS signal for uart0. Implement GPIO0_B5 as rts-gpios with RTS_ON_SEND option enabled (default) so that driver mode gets enabled while sending (RTS high) and receiver mode gets enabled while not sending (RTS low). In full-duplex mode (em485 is disabled), DE is connected to GPIO0_B5 and RE is grounded (enabled). Since GPIO0_B5 is implemented as rts-gpios, the driver mode gets enabled whenever we want to send something and RE is not affected (always enabled) in this case by the state of RTS. Signed-off-by: Farouk Bouabid Link: https://lore.kernel.org/r/20240208-dev-rx-enable-v6-2-39e68e17a339@theobroma-systems.com Signed-off-by: Heiko Stuebner --- arch/arm64/boot/dts/rockchip/px30-ringneck-haikou.dts | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/boot/dts/rockchip/px30-ringneck-haikou.dts b/arch/arm64/boot/dts/rockchip/px30-ringneck-haikou.dts index 16798eb770770..ae398acdcf45e 100644 --- a/arch/arm64/boot/dts/rockchip/px30-ringneck-haikou.dts +++ b/arch/arm64/boot/dts/rockchip/px30-ringneck-haikou.dts @@ -227,6 +227,7 @@ &uart5 { pinctrl-0 = <&uart5_xfer>; + rts-gpios = <&gpio0 RK_PB5 GPIO_ACTIVE_HIGH>; status = "okay"; }; -- 2.30.2