[PATCH] arm64: zynqmp: dts: Add rts delay property for rs485 mode on KD240

Michal Simek michal.simek at amd.com
Thu Jul 18 12:15:23 CEST 2024


From: Manikanta Guntupalli <manikanta.guntupalli at amd.com>

Add "rs485-rts-delay" property to uartps node with delay_rts_before_send
and delay_rts_after_send values as 10ms for rs485 mode on KD240.

10ms rts delay values have been chosen based on testing with rs485
temperature sensor (which is part of the kit) as safe minimum value
for reliable operation at a baud rate of 9600.

Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli at amd.com>
Signed-off-by: Michal Simek <michal.simek at amd.com>
---

 arch/arm/dts/zynqmp-sck-kd-g-revA.dtso | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/dts/zynqmp-sck-kd-g-revA.dtso b/arch/arm/dts/zynqmp-sck-kd-g-revA.dtso
index 1727a1cc15c1..4de29d5d3ff6 100644
--- a/arch/arm/dts/zynqmp-sck-kd-g-revA.dtso
+++ b/arch/arm/dts/zynqmp-sck-kd-g-revA.dtso
@@ -358,6 +358,7 @@
 	status = "okay";
 	rts-gpios = <&gpio 72 GPIO_ACTIVE_HIGH>;
 	linux,rs485-enabled-at-boot-time;
+	rs485-rts-delay = <10 10>;
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_uart0_default>;
 	assigned-clock-rates = <100000000>;
-- 
2.43.0



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