Skip to contentSkip to conversation

ARM: dts: aspeed: Drop syscon "reg-io-width" properties

PATCH In review Rob Herring (Arm) 2 participants 4 messages Aug 29, 2025 – Sep 10, 2025

Subsystems (2)
Device tree bindings Arm/Aspeed machine support
lore
Share & tools
lore

Rob Herring (Arm)

author maintainer
#0 lore raw

PATCH 1/1 ARM: dts: aspeed: Drop syscon "reg-io-width" properties

The default width is 4 bytes for "syscon" devices, so "reg-io-width" is redundant and can be dropped.

Signed-off-by Rob Herring (Arm) <[email protected]>
---
 arch/arm/boot/dts/aspeed/aspeed-g4.dtsi | 1 -
 arch/arm/boot/dts/aspeed/aspeed-g5.dtsi | 2 --
 arch/arm/boot/dts/aspeed/aspeed-g6.dtsi | 2 --
 3 files changed, 5 deletions(-)
arch/arm/boot/dts/aspeed/aspeed-g4.dtsi +0 -1
index 78c967812492..c3d4d916c69b 100644
@@ -356,7 +356,6 @@ vuart: serial@1e787000 {
 			lpc: lpc@1e789000 {
 				compatible = "aspeed,ast2400-lpc-v2", "simple-mfd", "syscon";
 				reg = <0x1e789000 0x1000>;
-				reg-io-width = <4>;
 
 				#address-cells = <1>;
 				#size-cells = <1>;
arch/arm/boot/dts/aspeed/aspeed-g5.dtsi +0 -2
index 57a699a7c149..39500bdb4747 100644
@@ -273,7 +273,6 @@ hace: crypto@1e6e3000 {
 			gfx: display@1e6e6000 {
 				compatible = "aspeed,ast2500-gfx", "syscon";
 				reg = <0x1e6e6000 0x1000>;
-				reg-io-width = <4>;
 				clocks = <&syscon ASPEED_CLK_GATE_D1CLK>;
 				resets = <&syscon ASPEED_RESET_CRT1>;
 				syscon = <&syscon>;

@@ -441,7 +440,6 @@ vuart: serial@1e787000 {
 			lpc: lpc@1e789000 {
 				compatible = "aspeed,ast2500-lpc-v2", "simple-mfd", "syscon";
 				reg = <0x1e789000 0x1000>;
-				reg-io-width = <4>;
 
 				#address-cells = <1>;
 				#size-cells = <1>;
arch/arm/boot/dts/aspeed/aspeed-g6.dtsi +0 -2
index 61983feb2a4e..f8662c8ac089 100644
@@ -382,7 +382,6 @@ rng: hwrng@1e6e2524 {
 			gfx: display@1e6e6000 {
 				compatible = "aspeed,ast2600-gfx", "syscon";
 				reg = <0x1e6e6000 0x1000>;
-				reg-io-width = <4>;
 				clocks = <&syscon ASPEED_CLK_GATE_D1CLK>;
 				resets = <&syscon ASPEED_RESET_GRAPHICS>;
 				syscon = <&syscon>;

@@ -572,7 +571,6 @@ peci0: peci-controller@1e78b000 {
 			lpc: lpc@1e789000 {
 				compatible = "aspeed,ast2600-lpc-v2", "simple-mfd", "syscon";
 				reg = <0x1e789000 0x1000>;
-				reg-io-width = <4>;
 
 				#address-cells = <1>;
 				#size-cells = <1>;
Signature · 1 line
2.50.1
maintainer
#1 lore raw
Quoted 2 lines · Rob Herring (Arm)

The default width is 4 bytes for "syscon" devices, so "reg-io-width" is redundant and can be dropped.

I had a quick look in the syscon bindings and can't see that this is documented? The driver implementation behaves this way though.

Andrew

author maintainer
#2 lore raw
Quoted 7 lines · Andrew Jeffery
Quoted 2 lines · Rob Herring (Arm)

The default width is 4 bytes for "syscon" devices, so "reg-io-width" is redundant and can be dropped.

I had a quick look in the syscon bindings and can't see that this is documented? The driver implementation behaves this way though.

It's not. I suppose we could add that to syscon-common.yaml, but that's only documentation. It has 0 effect on the schema validation. I would guess we have hundreds of syscon's that rely on the default.

Rob