lkml.org 
[lkml]   [2024]   [Jan]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
Subject[PATCH v5 5/6] arm64: dts: rockchip: rk3399-puma-haikou: add rs485 support on uart2
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
uart2 using ioctl, DE/RE are both connected to GPIO2_C3 which is the
RTS signal for uart0. Which means GPIO2_C3 is implemented as rs485
rx-enable gpio.

In full-duplex mode (em485 is disabled), DE is connected to GPIO2_C3 and
RE is grounded (enabled). This requires rx-enable gpio to be inactive to
enable DE as well.

Signed-off-by: Farouk Bouabid <farouk.bouabid@theobroma-systems.com>
---
arch/arm64/boot/dts/rockchip/rk3399-puma-haikou.dts | 4 +++-
1 file changed, 3 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 18a98c4648ea..576024c745ed 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-puma-haikou.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3399-puma-haikou.dts
@@ -273,11 +273,13 @@ &u2phy0_host {

&uart0 {
pinctrl-names = "default";
- pinctrl-0 = <&uart0_xfer &uart0_cts &uart0_rts>;
+ pinctrl-0 = <&uart0_xfer>;
status = "okay";
};

&uart2 {
+ rs485-rx-enable-gpios = <&gpio2 RK_PC3 GPIO_ACTIVE_LOW>;
+ rs485-rx-enable-inactive-when-rs485-disabled;
status = "okay";
};

--
2.34.1


\
 
 \ /
  Last update: 2024-05-27 14:35    [from the cache]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and my Meterkast|Read the blog