From 54448f711aa32f176534bbd7b1903cc6d1c8a50d Mon Sep 17 00:00:00 2001 From: Farouk Bouabid Date: Thu, 8 Feb 2024 16:39:55 +0100 Subject: [PATCH] arm64: dts: rockchip: add rs485 support on uart2 of rk3399-puma-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 GPIO2_C3 which is the RTS signal for uart0. Implement GPIO2_C3 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 GPIO2_C3 and RE is grounded (enabled). Since GPIO2_C3 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-v6-1-39e68e17a339@theobroma-systems.com Signed-off-by: Heiko Stuebner --- arch/arm64/boot/dts/rockchip/rk3399-puma-haikou.dts | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/arm64/boot/dts/rockchip/rk3399-puma-haikou.dts b/arch/arm64/boot/dts/rockchip/rk3399-puma-haikou.dts index 18a98c4648eae..2c3984a880af6 100644 --- a/arch/arm64/boot/dts/rockchip/rk3399-puma-haikou.dts +++ b/arch/arm64/boot/dts/rockchip/rk3399-puma-haikou.dts @@ -273,11 +273,12 @@ &uart0 { pinctrl-names = "default"; - pinctrl-0 = <&uart0_xfer &uart0_cts &uart0_rts>; + pinctrl-0 = <&uart0_xfer>; status = "okay"; }; &uart2 { + rts-gpios = <&gpio2 RK_PC3 GPIO_ACTIVE_HIGH>; status = "okay"; }; -- 2.30.2