[PATCH v2 2/4] dt-bindings: serial: stm32: override FIFO threshold properties

Erwan Le Ray
2021-04-13T17:40:44Z

Override rx-threshold and tx-threshold properties:
- extend description
- provide default and expected values

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>

Changes in v2:
Change added properties naming and factorize it in serial.yaml as proposed
by Rob Herring.

diff --git a/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml b/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml
index c69f8464cdf3..71a6426bc558 100644
--- a/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml
+++ b/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml
@@ -65,6 +65,18 @@ properties:
linux,rs485-enabled-at-boot-time: true
rs485-rx-during-tx: true

+ rx-threshold:
+ description:
+ If value is set to 1, RX FIFO threshold is disabled.
+ enum: [1, 2, 4, 8, 12, 14, 16]
+ default: 8
+
+ tx-threshold:
+ description:
+ If value is set to 1, TX FIFO threshold is disabled.
+ enum: [1, 2, 4, 8, 12, 14, 16]
+ default: 8
+
allOf:
- $ref: rs485.yaml#
- $ref: serial.yaml#
@@ -82,6 +94,17 @@ allOf:
then:
properties:
rx-tx-swap: false
+ - if:
+ properties:
+ compatible:
+ contains:
+ enum:
+ - st,stm32-uart
+ - st,stm32f7-uart
+ then:
+ properties:
+ rx-threshold: false
+ tx-threshold: false

required:
- compatible
@@ -96,13 +119,15 @@ examples:
- |
#include <dt-bindings/clock/stm32mp1-clks.h>
usart1: serial@40011000 {
- compatible = "st,stm32-uart";
+ compatible = "st,stm32h7-uart";
reg = <0x40011000 0x400>;
interrupts = <37>;
clocks = <&rcc 0 164>;
dmas = <&dma2 2 4 0x414 0x0>,
<&dma2 7 4 0x414 0x0>;
dma-names = "rx", "tx";
+ rx-threshold = <4>;
+ tx-threshold = <4>;
rs485-rts-active-low;
};

--
2.17.1