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

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

Posted by Rob Herring (Arm) 1 month ago

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) <robh@kernel.org>
---
 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(-)

diff --git a/arch/arm/boot/dts/aspeed/aspeed-g4.dtsi b/arch/arm/boot/dts/aspeed/aspeed-g4.dtsi
index 78c967812492..c3d4d916c69b 100644
--- a/arch/arm/boot/dts/aspeed/aspeed-g4.dtsi
+++ b/arch/arm/boot/dts/aspeed/aspeed-g4.dtsi
@@ -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>;
diff --git a/arch/arm/boot/dts/aspeed/aspeed-g5.dtsi b/arch/arm/boot/dts/aspeed/aspeed-g5.dtsi
index 57a699a7c149..39500bdb4747 100644
--- a/arch/arm/boot/dts/aspeed/aspeed-g5.dtsi
+++ b/arch/arm/boot/dts/aspeed/aspeed-g5.dtsi
@@ -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>;
diff --git a/arch/arm/boot/dts/aspeed/aspeed-g6.dtsi b/arch/arm/boot/dts/aspeed/aspeed-g6.dtsi
index 61983feb2a4e..f8662c8ac089 100644
--- a/arch/arm/boot/dts/aspeed/aspeed-g6.dtsi
+++ b/arch/arm/boot/dts/aspeed/aspeed-g6.dtsi
@@ -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>;
-- 
2.50.1

Re: [PATCH] ARM: dts: aspeed: Drop syscon "reg-io-width" properties

Posted by Andrew Jeffery 3 weeks, 2 days ago

On Fri, 29 Aug 2025 16:13:29 -0500, Rob Herring (Arm) wrote:
> The default width is 4 bytes for "syscon" devices, so "reg-io-width" is
> redundant and can be dropped.
> 
> 

Thanks, I've applied this to the BMC tree.

-- 
Andrew Jeffery <andrew@codeconstruct.com.au>

Re: [PATCH] ARM: dts: aspeed: Drop syscon "reg-io-width" properties

Posted by Andrew Jeffery 1 month ago

On Fri, 2025-08-29 at 16:13 -0500, Rob Herring (Arm) wrote:
> 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

Re: [PATCH] ARM: dts: aspeed: Drop syscon "reg-io-width" properties

Posted by Rob Herring 4 weeks, 1 day ago

On Wed, Sep 3, 2025 at 2:18 AM Andrew Jeffery
<andrew@codeconstruct.com.au> wrote:
>
> On Fri, 2025-08-29 at 16:13 -0500, Rob Herring (Arm) wrote:
> > 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