[PATCH v3 0/3] dt-bindings: mfd: syscon: Tighten checks

[PATCH v3 0/3] dt-bindings: mfd: syscon: Tighten checks

[Krzysztof Kozlowski]

Changes in v3:
- Drop patch #2:
  dt-bindings: mfd: syscon: Drop unneeded case for syscon + simple-mfd
- Bump dtschema requirement
- Link to v2: https://patch.msgid.link/20260608-n-dt-bindings-simple-bus-syscon-v2-0-0203e6c249dc@oss.qualcomm.com

Changes in v2:
1. New patches #2 and #3
1. Add missing part of patch #1, thus not adding Rob's Ack.
https://lore.kernel.org/all/20260531110404.12768-3-krzysztof.kozlowski@oss.qualcomm.com/

I tested dt_binding_check and dtbs_check for arm, arm64 and riscv and I
think I did not introduce new dtbs_check warnings. Old code anyway has
multiple abuses of syscon, thus tricky to judge for arm at least.

Best regards,
Krzysztof

---
Krzysztof Kozlowski (3):
      dt-bindings: mfd: syscon: Disallow simple-bus with syscon
      dt-bindings: mfd: syscon: Drop custom select for older dtschema
      ARM: dts: ti: Add specific compatibles for SCM conf nodes

 Documentation/devicetree/bindings/Makefile         |   2 +-
 .../devicetree/bindings/mfd/syscon-common.yaml     |  34 ++++++
 Documentation/devicetree/bindings/mfd/syscon.yaml  | 116 ---------------------
 arch/arm/boot/dts/ti/omap/am33xx-l4.dtsi           |   2 +-
 arch/arm/boot/dts/ti/omap/am437x-l4.dtsi           |   2 +-
 arch/arm/boot/dts/ti/omap/dm814x.dtsi              |   2 +-
 arch/arm/boot/dts/ti/omap/dm816x.dtsi              |   2 +-
 arch/arm/boot/dts/ti/omap/dra7-l4.dtsi             |   2 +-
 arch/arm/boot/dts/ti/omap/omap2430.dtsi            |   2 +-
 arch/arm/boot/dts/ti/omap/omap3.dtsi               |   2 +-
 arch/arm/boot/dts/ti/omap/omap4-l4.dtsi            |   2 +-
 arch/arm/boot/dts/ti/omap/omap5-l4.dtsi            |   6 +-
 12 files changed, 46 insertions(+), 128 deletions(-)
---
base-commit: 78f5e68a8d0a1123dd1b007688ccf0e6876a5c15
change-id: 20260608-n-dt-bindings-simple-bus-syscon-e39df408a02d

Best regards,
--  
Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>

[PATCH v3 1/3] dt-bindings: mfd: syscon: Disallow simple-bus with syscon

[Krzysztof Kozlowski]

"syscon" is a system controller with registers having their own
functions, thus not really a trivial MMIO simple bus.  "simple-bus" on
the other hand is just a bus on which multiple devices sit and the
"simple" means no functions are allowed here.

Combination of both "syscon" and "simple-bus" is abuse of DT for easier
instantiating of Linux device drivers so add a schema to disallow that.

Unfortunately there are a few old cases of that patterns, so add
exceptions:

1. "cznic,turris1x-cpld" and "img,pistachio-cr-periph" are already used
   in upstream DTS.

2. TI has several DTSI with a child of SCM device (e.g. "ti,am3-scm")
   using "syscon" and "simple-bus" but without a dedicated compatible
   documented anywhere.  Add new compatibles for such cases.

Additionally, add comments around code enforcing two or three
compatibles: it is similar safeguard detecting incorrect bindings.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>

---

Changes in v3:
1. s/ti,omap5-scm-conf/ti,omap5-sysc-padconf-global/ because it is more
   appropriate (specific)
2. Add comments, why simple-mfd+syscon has dedicated if:then:

Changes in v2:
1. Complete patch. I accidentally sent only part of it, built on top of
   internal WIP which I forgot to squash.
   I received Ack from Rob, but change is significant, so please kindly
   re-review.
---
 .../devicetree/bindings/mfd/syscon-common.yaml     | 34 ++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/Documentation/devicetree/bindings/mfd/syscon-common.yaml b/Documentation/devicetree/bindings/mfd/syscon-common.yaml
index 14a08e7bc8bd..2d5eef5add54 100644
--- a/Documentation/devicetree/bindings/mfd/syscon-common.yaml
+++ b/Documentation/devicetree/bindings/mfd/syscon-common.yaml
@@ -32,6 +32,7 @@ properties:
   compatible:
     contains:
       const: syscon
+    # Always require a specific compatible for syscon
     minItems: 2
     maxItems: 5  # Should be enough
 
@@ -52,11 +53,44 @@ allOf:
           contains:
             const: simple-mfd
     then:
+      # Always require a specific compatible for syscon with simple-mfd
       properties:
         compatible:
           minItems: 3
           maxItems: 5
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: simple-bus
+    then:
+      # simple-bus conflicts with syscon - if a device is a system controller
+      # with miscellaneous registers, then it has at least one dedicated
+      # function thus it is not a simple bus. Allow existing exceptions.
+      if:
+        properties:
+          compatible:
+            not:
+              contains:
+                # This list CANNOT grow
+                enum:
+                  - cznic,turris1x-cpld
+                  - img,pistachio-cr-periph
+                  - ti,am3352-scm-conf
+                  - ti,am4372-scm-conf
+                  - ti,dm814-scm-conf
+                  - ti,dm8168-scm-conf
+                  - ti,dra7-scm-conf
+                  - ti,omap2-scm-conf
+                  - ti,omap3-scm-conf
+                  - ti,omap4-sysc-padconf-global
+                  - ti,omap5-scm-wkup-conf
+                  - ti,omap5-sysc-padconf-global
+      then:
+        required:
+          - incorrect-usage-of-simple-bus-and-syscon
+
 additionalProperties: true
 
 examples:

-- 
2.53.0

Re: [PATCH v3 1/3] dt-bindings: mfd: syscon: Disallow simple-bus with syscon

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The patch introduces several new compatible strings (e.g., `ti,am3352-scm-conf`) to the exception list without documenting them in any valid dt-binding schema. This causes a bisectability breakage in `dtbs_check` during the series and leaves permanent 'undocumented compatible' warnings at the end of the series.
--

commit 0cddec624a3b6ba2f0c447b95621f32101d2e31f
Author: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>

dt-bindings: mfd: syscon: Disallow simple-bus with syscon

This commit adds a schema to disallow the combination of syscon and
simple-bus compatibles. It includes an exception list for legacy
configurations that currently rely on this pattern.

> diff --git a/Documentation/devicetree/bindings/mfd/syscon-common.yaml b/Documentation/devicetree/bindings/mfd/syscon-common.yaml
> index 14a08e7bc8bdd..2d5eef5add544 100644
> --- a/Documentation/devicetree/bindings/mfd/syscon-common.yaml
> +++ b/Documentation/devicetree/bindings/mfd/syscon-common.yaml
[ ... ]
> @@ -52,11 +53,44 @@ allOf:
>            contains:
>              const: simple-mfd
>      then:
> +      # Always require a specific compatible for syscon with simple-mfd
>        properties:
>          compatible:
>            minItems: 3
>            maxItems: 5
>  
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            const: simple-bus
> +    then:
> +      # simple-bus conflicts with syscon - if a device is a system controller
> +      # with miscellaneous registers, then it has at least one dedicated
> +      # function thus it is not a simple bus. Allow existing exceptions.
> +      if:
> +        properties:
> +          compatible:
> +            not:
> +              contains:
> +                # This list CANNOT grow

[Severity: Medium]
Will this break bisectability for dtbs_check? Since the DTS files are
updated later in the series, it seems like existing TI DTS files using syscon
and simple-bus without these new specific compatibles will fail validation
when this patch is applied.

> +                enum:
> +                  - cznic,turris1x-cpld
> +                  - img,pistachio-cr-periph
> +                  - ti,am3352-scm-conf
> +                  - ti,am4372-scm-conf
> +                  - ti,dm814-scm-conf
> +                  - ti,dm8168-scm-conf
> +                  - ti,dra7-scm-conf
> +                  - ti,omap2-scm-conf
> +                  - ti,omap3-scm-conf
> +                  - ti,omap4-sysc-padconf-global
> +                  - ti,omap5-scm-wkup-conf
> +                  - ti,omap5-sysc-padconf-global

[Severity: Medium]
Are these new TI compatible strings documented in a dedicated binding schema?

Being listed inside this enum block doesn't document them for dtschema, which
might result in continuous undocumented compatible warnings for all the
updated TI boards at the end of the series.

> +      then:
> +        required:
> +          - incorrect-usage-of-simple-bus-and-syscon

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260608-n-dt-bindings-simple-bus-syscon-v3-0-4eba9ec1212a@oss.qualcomm.com?part=1

Re: [PATCH v3 1/3] dt-bindings: mfd: syscon: Disallow simple-bus with syscon

[Conor Dooley]

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On Mon, Jun 08, 2026 at 08:54:05PM +0000, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Medium] The patch introduces several new compatible strings (e.g., `ti,am3352-scm-conf`) to the exception list without documenting them in any valid dt-binding schema. This causes a bisectability breakage in `dtbs_check` during the series and leaves permanent 'undocumented compatible' warnings at the end of the series.
> --
> 
> commit 0cddec624a3b6ba2f0c447b95621f32101d2e31f
> Author: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
> 
> dt-bindings: mfd: syscon: Disallow simple-bus with syscon
> 
> This commit adds a schema to disallow the combination of syscon and
> simple-bus compatibles. It includes an exception list for legacy
> configurations that currently rely on this pattern.
> 
> > diff --git a/Documentation/devicetree/bindings/mfd/syscon-common.yaml b/Documentation/devicetree/bindings/mfd/syscon-common.yaml
> > index 14a08e7bc8bdd..2d5eef5add544 100644
> > --- a/Documentation/devicetree/bindings/mfd/syscon-common.yaml
> > +++ b/Documentation/devicetree/bindings/mfd/syscon-common.yaml
> [ ... ]
> > @@ -52,11 +53,44 @@ allOf:
> >            contains:
> >              const: simple-mfd
> >      then:
> > +      # Always require a specific compatible for syscon with simple-mfd
> >        properties:
> >          compatible:
> >            minItems: 3
> >            maxItems: 5
> >  
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          contains:
> > +            const: simple-bus
> > +    then:
> > +      # simple-bus conflicts with syscon - if a device is a system controller
> > +      # with miscellaneous registers, then it has at least one dedicated
> > +      # function thus it is not a simple bus. Allow existing exceptions.
> > +      if:
> > +        properties:
> > +          compatible:
> > +            not:
> > +              contains:
> > +                # This list CANNOT grow
> 
> [Severity: Medium]
> Will this break bisectability for dtbs_check? Since the DTS files are
> updated later in the series, it seems like existing TI DTS files using syscon
> and simple-bus without these new specific compatibles will fail validation
> when this patch is applied.

Perhaps worth telling the sashiko people that transitory warnings like
this aren't something we care about, especially since even the normal
development process for devicetrees introduces validation issues in the
platform maintainer branches.

[-- Attachment #2: signature.asc --]
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Re: [PATCH v3 1/3] dt-bindings: mfd: syscon: Disallow simple-bus with syscon

[Rob Herring]

On Tue, Jun 09, 2026 at 05:36:30PM +0100, Conor Dooley wrote:
> On Mon, Jun 08, 2026 at 08:54:05PM +0000, sashiko-bot@kernel.org wrote:
> > Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> > - [Medium] The patch introduces several new compatible strings (e.g., `ti,am3352-scm-conf`) to the exception list without documenting them in any valid dt-binding schema. This causes a bisectability breakage in `dtbs_check` during the series and leaves permanent 'undocumented compatible' warnings at the end of the series.
> > --
> > 
> > commit 0cddec624a3b6ba2f0c447b95621f32101d2e31f
> > Author: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
> > 
> > dt-bindings: mfd: syscon: Disallow simple-bus with syscon
> > 
> > This commit adds a schema to disallow the combination of syscon and
> > simple-bus compatibles. It includes an exception list for legacy
> > configurations that currently rely on this pattern.
> > 
> > > diff --git a/Documentation/devicetree/bindings/mfd/syscon-common.yaml b/Documentation/devicetree/bindings/mfd/syscon-common.yaml
> > > index 14a08e7bc8bdd..2d5eef5add544 100644
> > > --- a/Documentation/devicetree/bindings/mfd/syscon-common.yaml
> > > +++ b/Documentation/devicetree/bindings/mfd/syscon-common.yaml
> > [ ... ]
> > > @@ -52,11 +53,44 @@ allOf:
> > >            contains:
> > >              const: simple-mfd
> > >      then:
> > > +      # Always require a specific compatible for syscon with simple-mfd
> > >        properties:
> > >          compatible:
> > >            minItems: 3
> > >            maxItems: 5
> > >  
> > > +  - if:
> > > +      properties:
> > > +        compatible:
> > > +          contains:
> > > +            const: simple-bus
> > > +    then:
> > > +      # simple-bus conflicts with syscon - if a device is a system controller
> > > +      # with miscellaneous registers, then it has at least one dedicated
> > > +      # function thus it is not a simple bus. Allow existing exceptions.
> > > +      if:
> > > +        properties:
> > > +          compatible:
> > > +            not:
> > > +              contains:
> > > +                # This list CANNOT grow
> > 
> > [Severity: Medium]
> > Will this break bisectability for dtbs_check? Since the DTS files are
> > updated later in the series, it seems like existing TI DTS files using syscon
> > and simple-bus without these new specific compatibles will fail validation
> > when this patch is applied.
> 
> Perhaps worth telling the sashiko people that transitory warnings like
> this aren't something we care about, especially since even the normal
> development process for devicetrees introduces validation issues in the
> platform maintainer branches.

I think that is on us to tweak the review prompts. There's already one 
for DT that none of us wrote. Though really I don't think that's all 
that maintainable. Really, IMO sashiko itself should be able to 
incorporate feedback like any other reviewer/developer.

Rob

[PATCH v3 2/3] dt-bindings: mfd: syscon: Drop custom select for older dtschema

[Krzysztof Kozlowski]

Older dtschema <2024.02 required custom select to avoid applying this
binding to anything having "syscon" compatible.  That's not the case
anymore and this additional select has two headaches:

1. Duplicates all the compatibles listed in the schema.

2. Is error-prone, because it requires contributor to add the compatible
   in two places, otherwise the schema will be silently ignored.
   The select list already misses mentioning compatibles:
   mediatek,mt8365-infracfg-nao and renesas,r9a08g046-lvds-cmn (with the
   latter being reverted for different reasons).

This requires bumping minimum dtschema requirement to v2024.04, which
feels old enough to be a safe requirement.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>

---

Changes in v3:
1. Bump dtschema requirement

Changes in v2:
1. New patch
---
 Documentation/devicetree/bindings/Makefile        |   2 +-
 Documentation/devicetree/bindings/mfd/syscon.yaml | 116 ----------------------
 2 files changed, 1 insertion(+), 117 deletions(-)

diff --git a/Documentation/devicetree/bindings/Makefile b/Documentation/devicetree/bindings/Makefile
index 7b668f7fd400..40c2094f47c2 100644
--- a/Documentation/devicetree/bindings/Makefile
+++ b/Documentation/devicetree/bindings/Makefile
@@ -6,7 +6,7 @@ DT_MK_SCHEMA ?= dt-mk-schema
 DT_SCHEMA_LINT = $(shell which yamllint || \
   echo "warning: python package 'yamllint' not installed, skipping" >&2)
 
-DT_SCHEMA_MIN_VERSION = 2023.9
+DT_SCHEMA_MIN_VERSION = 2024.4
 
 PHONY += check_dtschema_version
 check_dtschema_version:
diff --git a/Documentation/devicetree/bindings/mfd/syscon.yaml b/Documentation/devicetree/bindings/mfd/syscon.yaml
index 9c81010d5a74..b70018bf1bcf 100644
--- a/Documentation/devicetree/bindings/mfd/syscon.yaml
+++ b/Documentation/devicetree/bindings/mfd/syscon.yaml
@@ -19,122 +19,6 @@ description: |
 maintainers:
   - Lee Jones <lee@kernel.org>
 
-# Need a select with all compatibles listed for compatibility with older
-# dtschema (<2024.02), so this will not be selected for other schemas having
-# syscon fallback.
-select:
-  properties:
-    compatible:
-      contains:
-        enum:
-          - airoha,en7581-pbus-csr
-          - al,alpine-sysfabric-service
-          - allwinner,sun8i-a83t-system-controller
-          - allwinner,sun8i-h3-system-controller
-          - allwinner,sun8i-v3s-system-controller
-          - allwinner,sun50i-a64-system-controller
-          - altr,l3regs
-          - altr,sdr-ctl
-          - amd,pensando-elba-syscon
-          - amlogic,meson-mx-assist
-          - amlogic,meson-mx-bootrom
-          - amlogic,meson8-analog-top
-          - amlogic,meson8b-analog-top
-          - amlogic,meson8-pmu
-          - amlogic,meson8b-pmu
-          - apm,merlin-poweroff-mailbox
-          - apm,mustang-poweroff-mailbox
-          - apm,xgene-csw
-          - apm,xgene-efuse
-          - apm,xgene-mcb
-          - apm,xgene-rb
-          - apm,xgene-scu
-          - atmel,sama5d2-sfrbu
-          - atmel,sama5d3-nfc-io
-          - atmel,sama5d3-sfrbu
-          - atmel,sama5d4-sfrbu
-          - axis,artpec6-syscon
-          - brcm,cru-clkset
-          - brcm,sr-cdru
-          - brcm,sr-mhb
-          - cirrus,ep7209-syscon1
-          - cirrus,ep7209-syscon2
-          - cirrus,ep7209-syscon3
-          - cnxt,cx92755-uc
-          - econet,en751221-chip-scu
-          - freecom,fsg-cs2-system-controller
-          - fsl,imx93-aonmix-ns-syscfg
-          - fsl,imx93-wakeupmix-syscfg
-          - fsl,ls1088a-reset
-          - fsl,vf610-anatop
-          - fsl,vf610-mscm-cpucfg
-          - hisilicon,dsa-subctrl
-          - hisilicon,hi6220-sramctrl
-          - hisilicon,hip04-ppe
-          - hisilicon,pcie-sas-subctrl
-          - hisilicon,peri-subctrl
-          - hpe,gxp-sysreg
-          - loongson,ls1b-syscon
-          - loongson,ls1c-syscon
-          - lsi,axxia-syscon
-          - marvell,armada-3700-cpu-misc
-          - marvell,armada-3700-nb-pm
-          - marvell,armada-3700-avs
-          - marvell,armada-3700-usb2-host-device-misc
-          - marvell,armada-3700-usb2-host-misc
-          - marvell,dove-global-config
-          - mediatek,mt2701-pctl-a-syscfg
-          - mediatek,mt2712-pctl-a-syscfg
-          - mediatek,mt6397-pctl-pmic-syscfg
-          - mediatek,mt7981-topmisc
-          - mediatek,mt7988-topmisc
-          - mediatek,mt8135-pctl-a-syscfg
-          - mediatek,mt8135-pctl-b-syscfg
-          - mediatek,mt8173-pctl-a-syscfg
-          - mediatek,mt8365-syscfg
-          - microchip,lan966x-cpu-syscon
-          - microchip,mpfs-control-scb
-          - microchip,mpfs-sysreg-scb
-          - microchip,sam9x60-sfr
-          - microchip,sama7d65-ddr3phy
-          - microchip,sama7d65-sfrbu
-          - microchip,sama7g5-ddr3phy
-          - mscc,ocelot-cpu-syscon
-          - mstar,msc313-pmsleep
-          - nuvoton,ma35d1-sys
-          - nuvoton,wpcm450-shm
-          - nxp,s32g2-gpr
-          - nxp,s32g3-gpr
-          - qcom,apq8064-mmss-sfpb
-          - qcom,apq8064-sps-sic
-          - rockchip,px30-qos
-          - rockchip,rk3036-qos
-          - rockchip,rk3066-qos
-          - rockchip,rk3128-qos
-          - rockchip,rk3228-qos
-          - rockchip,rk3288-qos
-          - rockchip,rk3368-qos
-          - rockchip,rk3399-qos
-          - rockchip,rk3528-qos
-          - rockchip,rk3562-qos
-          - rockchip,rk3568-qos
-          - rockchip,rk3576-qos
-          - rockchip,rk3588-qos
-          - rockchip,rv1126-qos
-          - st,spear1340-misc
-          - stericsson,nomadik-pmu
-          - starfive,jh7100-sysmain
-          - ti,am62-opp-efuse-table
-          - ti,am62-usb-phy-ctrl
-          - ti,am625-dss-oldi-io-ctrl
-          - ti,am62p-cpsw-mac-efuse
-          - ti,am654-dss-oldi-io-ctrl
-          - ti,j784s4-acspcie-proxy-ctrl
-          - ti,j784s4-pcie-ctrl
-          - ti,keystone-pllctrl
-  required:
-    - compatible
-
 properties:
   compatible:
     oneOf:

-- 
2.53.0

Re: [PATCH v3 2/3] dt-bindings: mfd: syscon: Drop custom select for older dtschema

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 6856 bytes --]

On Mon, Jun 08, 2026 at 10:44:25PM +0200, Krzysztof Kozlowski wrote:
> Older dtschema <2024.02 required custom select to avoid applying this
> binding to anything having "syscon" compatible.  That's not the case
> anymore and this additional select has two headaches:
> 
> 1. Duplicates all the compatibles listed in the schema.
> 
> 2. Is error-prone, because it requires contributor to add the compatible
>    in two places, otherwise the schema will be silently ignored.
>    The select list already misses mentioning compatibles:
>    mediatek,mt8365-infracfg-nao and renesas,r9a08g046-lvds-cmn (with the
>    latter being reverted for different reasons).
> 
> This requires bumping minimum dtschema requirement to v2024.04, which
> feels old enough to be a safe requirement.

I agree, seems reasonable enough given it's a jump from 2023.09 and not
some large jump.
The diff is nice too!
I assume Rob will be taking it, but just in case..
Acked-by: Conor Dooley <conor.dooley@microchip.com>

Cheers,
Conor.

> 
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
> 
> ---
> 
> Changes in v3:
> 1. Bump dtschema requirement
> 
> Changes in v2:
> 1. New patch
> ---
>  Documentation/devicetree/bindings/Makefile        |   2 +-
>  Documentation/devicetree/bindings/mfd/syscon.yaml | 116 ----------------------
>  2 files changed, 1 insertion(+), 117 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/Makefile b/Documentation/devicetree/bindings/Makefile
> index 7b668f7fd400..40c2094f47c2 100644
> --- a/Documentation/devicetree/bindings/Makefile
> +++ b/Documentation/devicetree/bindings/Makefile
> @@ -6,7 +6,7 @@ DT_MK_SCHEMA ?= dt-mk-schema
>  DT_SCHEMA_LINT = $(shell which yamllint || \
>    echo "warning: python package 'yamllint' not installed, skipping" >&2)
>  
> -DT_SCHEMA_MIN_VERSION = 2023.9
> +DT_SCHEMA_MIN_VERSION = 2024.4
>  
>  PHONY += check_dtschema_version
>  check_dtschema_version:
> diff --git a/Documentation/devicetree/bindings/mfd/syscon.yaml b/Documentation/devicetree/bindings/mfd/syscon.yaml
> index 9c81010d5a74..b70018bf1bcf 100644
> --- a/Documentation/devicetree/bindings/mfd/syscon.yaml
> +++ b/Documentation/devicetree/bindings/mfd/syscon.yaml
> @@ -19,122 +19,6 @@ description: |
>  maintainers:
>    - Lee Jones <lee@kernel.org>
>  
> -# Need a select with all compatibles listed for compatibility with older
> -# dtschema (<2024.02), so this will not be selected for other schemas having
> -# syscon fallback.
> -select:
> -  properties:
> -    compatible:
> -      contains:
> -        enum:
> -          - airoha,en7581-pbus-csr
> -          - al,alpine-sysfabric-service
> -          - allwinner,sun8i-a83t-system-controller
> -          - allwinner,sun8i-h3-system-controller
> -          - allwinner,sun8i-v3s-system-controller
> -          - allwinner,sun50i-a64-system-controller
> -          - altr,l3regs
> -          - altr,sdr-ctl
> -          - amd,pensando-elba-syscon
> -          - amlogic,meson-mx-assist
> -          - amlogic,meson-mx-bootrom
> -          - amlogic,meson8-analog-top
> -          - amlogic,meson8b-analog-top
> -          - amlogic,meson8-pmu
> -          - amlogic,meson8b-pmu
> -          - apm,merlin-poweroff-mailbox
> -          - apm,mustang-poweroff-mailbox
> -          - apm,xgene-csw
> -          - apm,xgene-efuse
> -          - apm,xgene-mcb
> -          - apm,xgene-rb
> -          - apm,xgene-scu
> -          - atmel,sama5d2-sfrbu
> -          - atmel,sama5d3-nfc-io
> -          - atmel,sama5d3-sfrbu
> -          - atmel,sama5d4-sfrbu
> -          - axis,artpec6-syscon
> -          - brcm,cru-clkset
> -          - brcm,sr-cdru
> -          - brcm,sr-mhb
> -          - cirrus,ep7209-syscon1
> -          - cirrus,ep7209-syscon2
> -          - cirrus,ep7209-syscon3
> -          - cnxt,cx92755-uc
> -          - econet,en751221-chip-scu
> -          - freecom,fsg-cs2-system-controller
> -          - fsl,imx93-aonmix-ns-syscfg
> -          - fsl,imx93-wakeupmix-syscfg
> -          - fsl,ls1088a-reset
> -          - fsl,vf610-anatop
> -          - fsl,vf610-mscm-cpucfg
> -          - hisilicon,dsa-subctrl
> -          - hisilicon,hi6220-sramctrl
> -          - hisilicon,hip04-ppe
> -          - hisilicon,pcie-sas-subctrl
> -          - hisilicon,peri-subctrl
> -          - hpe,gxp-sysreg
> -          - loongson,ls1b-syscon
> -          - loongson,ls1c-syscon
> -          - lsi,axxia-syscon
> -          - marvell,armada-3700-cpu-misc
> -          - marvell,armada-3700-nb-pm
> -          - marvell,armada-3700-avs
> -          - marvell,armada-3700-usb2-host-device-misc
> -          - marvell,armada-3700-usb2-host-misc
> -          - marvell,dove-global-config
> -          - mediatek,mt2701-pctl-a-syscfg
> -          - mediatek,mt2712-pctl-a-syscfg
> -          - mediatek,mt6397-pctl-pmic-syscfg
> -          - mediatek,mt7981-topmisc
> -          - mediatek,mt7988-topmisc
> -          - mediatek,mt8135-pctl-a-syscfg
> -          - mediatek,mt8135-pctl-b-syscfg
> -          - mediatek,mt8173-pctl-a-syscfg
> -          - mediatek,mt8365-syscfg
> -          - microchip,lan966x-cpu-syscon
> -          - microchip,mpfs-control-scb
> -          - microchip,mpfs-sysreg-scb
> -          - microchip,sam9x60-sfr
> -          - microchip,sama7d65-ddr3phy
> -          - microchip,sama7d65-sfrbu
> -          - microchip,sama7g5-ddr3phy
> -          - mscc,ocelot-cpu-syscon
> -          - mstar,msc313-pmsleep
> -          - nuvoton,ma35d1-sys
> -          - nuvoton,wpcm450-shm
> -          - nxp,s32g2-gpr
> -          - nxp,s32g3-gpr
> -          - qcom,apq8064-mmss-sfpb
> -          - qcom,apq8064-sps-sic
> -          - rockchip,px30-qos
> -          - rockchip,rk3036-qos
> -          - rockchip,rk3066-qos
> -          - rockchip,rk3128-qos
> -          - rockchip,rk3228-qos
> -          - rockchip,rk3288-qos
> -          - rockchip,rk3368-qos
> -          - rockchip,rk3399-qos
> -          - rockchip,rk3528-qos
> -          - rockchip,rk3562-qos
> -          - rockchip,rk3568-qos
> -          - rockchip,rk3576-qos
> -          - rockchip,rk3588-qos
> -          - rockchip,rv1126-qos
> -          - st,spear1340-misc
> -          - stericsson,nomadik-pmu
> -          - starfive,jh7100-sysmain
> -          - ti,am62-opp-efuse-table
> -          - ti,am62-usb-phy-ctrl
> -          - ti,am625-dss-oldi-io-ctrl
> -          - ti,am62p-cpsw-mac-efuse
> -          - ti,am654-dss-oldi-io-ctrl
> -          - ti,j784s4-acspcie-proxy-ctrl
> -          - ti,j784s4-pcie-ctrl
> -          - ti,keystone-pllctrl
> -  required:
> -    - compatible
> -
>  properties:
>    compatible:
>      oneOf:
> 
> -- 
> 2.53.0
> 

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[PATCH v3 3/3] ARM: dts: ti: Add specific compatibles for SCM conf nodes

[Krzysztof Kozlowski]

writing-bindings.rst rules dictate that "syscon" must come with a
specific compatible identifying the register layout.  Add specific
compatibles for these devices.

This also allows to solve a different problem: "syscon" is contradictory
to "simple-bus".  A system controller with registers having their own
functions is not really a trivial MMIO simple bus.  These two cannot be
used together, unless listed as an exception.

Reviewed-by: Andreas Kemnade <andreas@kemnade.info>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>

---

Changes in v3:
1. s/ti,omap5-scm-conf/ti,omap5-sysc-padconf-global/ because it is more
   appropriate (specific)
---
 arch/arm/boot/dts/ti/omap/am33xx-l4.dtsi | 2 +-
 arch/arm/boot/dts/ti/omap/am437x-l4.dtsi | 2 +-
 arch/arm/boot/dts/ti/omap/dm814x.dtsi    | 2 +-
 arch/arm/boot/dts/ti/omap/dm816x.dtsi    | 2 +-
 arch/arm/boot/dts/ti/omap/dra7-l4.dtsi   | 2 +-
 arch/arm/boot/dts/ti/omap/omap2430.dtsi  | 2 +-
 arch/arm/boot/dts/ti/omap/omap3.dtsi     | 2 +-
 arch/arm/boot/dts/ti/omap/omap4-l4.dtsi  | 2 +-
 arch/arm/boot/dts/ti/omap/omap5-l4.dtsi  | 6 +++---
 9 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/arch/arm/boot/dts/ti/omap/am33xx-l4.dtsi b/arch/arm/boot/dts/ti/omap/am33xx-l4.dtsi
index 89d16fcc773e..1e09d2b48925 100644
--- a/arch/arm/boot/dts/ti/omap/am33xx-l4.dtsi
+++ b/arch/arm/boot/dts/ti/omap/am33xx-l4.dtsi
@@ -308,7 +308,7 @@ am33xx_pinmux: pinmux@800 {
 				};
 
 				scm_conf: scm_conf@0 {
-					compatible = "syscon", "simple-bus";
+					compatible = "ti,am3352-scm-conf", "syscon", "simple-bus";
 					reg = <0x0 0x800>;
 					#address-cells = <1>;
 					#size-cells = <1>;
diff --git a/arch/arm/boot/dts/ti/omap/am437x-l4.dtsi b/arch/arm/boot/dts/ti/omap/am437x-l4.dtsi
index e08f356e71cb..30fcce33f4b7 100644
--- a/arch/arm/boot/dts/ti/omap/am437x-l4.dtsi
+++ b/arch/arm/boot/dts/ti/omap/am437x-l4.dtsi
@@ -301,7 +301,7 @@ am43xx_pinmux: pinmux@800 {
 				};
 
 				scm_conf: scm_conf@0 {
-					compatible = "syscon", "simple-bus";
+					compatible = "ti,am4372-scm-conf", "syscon", "simple-bus";
 					reg = <0x0 0x800>;
 					#address-cells = <1>;
 					#size-cells = <1>;
diff --git a/arch/arm/boot/dts/ti/omap/dm814x.dtsi b/arch/arm/boot/dts/ti/omap/dm814x.dtsi
index 27d1f35a31fd..9e02bfa5c3a2 100644
--- a/arch/arm/boot/dts/ti/omap/dm814x.dtsi
+++ b/arch/arm/boot/dts/ti/omap/dm814x.dtsi
@@ -432,7 +432,7 @@ control: control@140000 {
 				ranges = <0 0x140000 0x20000>;
 
 				scm_conf: scm_conf@0 {
-					compatible = "syscon", "simple-bus";
+					compatible = "ti,dm814-scm-conf", "syscon", "simple-bus";
 					reg = <0x0 0x800>;
 					#address-cells = <1>;
 					#size-cells = <1>;
diff --git a/arch/arm/boot/dts/ti/omap/dm816x.dtsi b/arch/arm/boot/dts/ti/omap/dm816x.dtsi
index a1e0e904e0f0..ee0090f7aa64 100644
--- a/arch/arm/boot/dts/ti/omap/dm816x.dtsi
+++ b/arch/arm/boot/dts/ti/omap/dm816x.dtsi
@@ -100,7 +100,7 @@ dm816x_pinmux: pinmux@800 {
 
 			/* Device Configuration Registers */
 			scm_conf: syscon@600 {
-				compatible = "syscon", "simple-bus";
+				compatible = "ti,dm8168-scm-conf", "syscon", "simple-bus";
 				reg = <0x600 0x110>;
 				#address-cells = <1>;
 				#size-cells = <1>;
diff --git a/arch/arm/boot/dts/ti/omap/dra7-l4.dtsi b/arch/arm/boot/dts/ti/omap/dra7-l4.dtsi
index c8d325b0f57b..9df7648c4b79 100644
--- a/arch/arm/boot/dts/ti/omap/dra7-l4.dtsi
+++ b/arch/arm/boot/dts/ti/omap/dra7-l4.dtsi
@@ -64,7 +64,7 @@ scm: scm@0 {
 				ranges = <0 0 0x2000>;
 
 				scm_conf: scm_conf@0 {
-					compatible = "syscon", "simple-bus";
+					compatible = "ti,dra7-scm-conf", "syscon", "simple-bus";
 					reg = <0x0 0x1400>;
 					#address-cells = <1>;
 					#size-cells = <1>;
diff --git a/arch/arm/boot/dts/ti/omap/omap2430.dtsi b/arch/arm/boot/dts/ti/omap/omap2430.dtsi
index 222613d2a4d1..01bd471f9223 100644
--- a/arch/arm/boot/dts/ti/omap/omap2430.dtsi
+++ b/arch/arm/boot/dts/ti/omap/omap2430.dtsi
@@ -50,7 +50,7 @@ omap2430_pmx: pinmux@30 {
 				};
 
 				scm_conf: scm_conf@270 {
-					compatible = "syscon",
+					compatible = "ti,omap2-scm-conf", "syscon",
 						     "simple-bus";
 					reg = <0x270 0x240>;
 					#address-cells = <1>;
diff --git a/arch/arm/boot/dts/ti/omap/omap3.dtsi b/arch/arm/boot/dts/ti/omap/omap3.dtsi
index 959069e24730..447736d2e53c 100644
--- a/arch/arm/boot/dts/ti/omap/omap3.dtsi
+++ b/arch/arm/boot/dts/ti/omap/omap3.dtsi
@@ -116,7 +116,7 @@ omap3_pmx_core: pinmux@30 {
 				};
 
 				scm_conf: scm_conf@270 {
-					compatible = "syscon", "simple-bus";
+					compatible = "ti,omap3-scm-conf", "syscon", "simple-bus";
 					reg = <0x270 0x330>;
 					#address-cells = <1>;
 					#size-cells = <1>;
diff --git a/arch/arm/boot/dts/ti/omap/omap4-l4.dtsi b/arch/arm/boot/dts/ti/omap/omap4-l4.dtsi
index 4c78a0b28fab..c1afc49f456c 100644
--- a/arch/arm/boot/dts/ti/omap/omap4-l4.dtsi
+++ b/arch/arm/boot/dts/ti/omap/omap4-l4.dtsi
@@ -681,7 +681,7 @@ omap4_pmx_core: pinmux@40 {
 			};
 
 			omap4_padconf_global: omap4_padconf_global@5a0 {
-				compatible = "syscon",
+				compatible = "ti,omap4-sysc-padconf-global", "syscon",
 					     "simple-bus";
 				reg = <0x5a0 0x170>;
 				#address-cells = <1>;
diff --git a/arch/arm/boot/dts/ti/omap/omap5-l4.dtsi b/arch/arm/boot/dts/ti/omap/omap5-l4.dtsi
index 915870eb5c99..72849e1c95b0 100644
--- a/arch/arm/boot/dts/ti/omap/omap5-l4.dtsi
+++ b/arch/arm/boot/dts/ti/omap/omap5-l4.dtsi
@@ -96,8 +96,7 @@ omap5_pmx_core: pinmux@40 {
 				};
 
 				omap5_padconf_global: omap5_padconf_global@5a0 {
-					compatible = "syscon",
-						     "simple-bus";
+					compatible = "ti,omap5-sysc-padconf-global", "syscon", "simple-bus";
 					reg = <0x5a0 0xec>;
 					#address-cells = <1>;
 					#size-cells = <1>;
@@ -2311,7 +2310,8 @@ omap5_scm_wkup_pad_conf: omap5_scm_wkup_pad_conf@da0 {
 				ranges = <0 0 0x60>;
 
 				scm_wkup_pad_conf: scm_conf@0 {
-					compatible = "syscon", "simple-bus";
+					compatible = "ti,omap5-scm-wkup-conf",
+						     "syscon", "simple-bus";
 					reg = <0x0 0x60>;
 					#address-cells = <1>;
 					#size-cells = <1>;

-- 
2.53.0

Re: [PATCH v3 3/3] ARM: dts: ti: Add specific compatibles for SCM conf nodes

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Incomplete refactoring: Several SCM conf nodes still retain a standalone 'syscon' compatible string.
--

commit f27db69296633e59ec29af047a99e08ea07397ae
Author: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>

ARM: dts: ti: Add specific compatibles for SCM conf nodes

The commit adds specific compatible strings to "syscon" and "simple-bus"
nodes in TI OMAP device trees. This addresses device tree binding
requirements that "syscon" must come with a specific compatible, and also
resolves contradictions when used with "simple-bus".

> diff --git a/arch/arm/boot/dts/ti/omap/dra7-l4.dtsi b/arch/arm/boot/dts/ti/omap/dra7-l4.dtsi
> index c8d325b0f57b2..9df7648c4b793 100644
> --- a/arch/arm/boot/dts/ti/omap/dra7-l4.dtsi
> +++ b/arch/arm/boot/dts/ti/omap/dra7-l4.dtsi
> @@ -64,7 +64,7 @@ scm: scm@0 {
>  				ranges = <0 0 0x2000>;
>  
>  				scm_conf: scm_conf@0 {
> -					compatible = "syscon", "simple-bus";
> +					compatible = "ti,dra7-scm-conf", "syscon", "simple-bus";
>  					reg = <0x0 0x1400>;
>  					#address-cells = <1>;
>  					#size-cells = <1>;

[Severity: Medium]
Does this patch miss other standalone "syscon" nodes in the updated files?

In arch/arm/boot/dts/ti/omap/dra7-l4.dtsi, there are other SCM conf nodes
that still only have compatible = "syscon", such as scm_conf1@1c04:

				scm_conf1: scm_conf@1c04 {
					compatible = "syscon";
					reg = <0x1c04 0x0020>;

and scm_wkup@0:

			scm_wkup: scm_conf@0 {
				compatible = "syscon";
				reg = <0 0x1000>;

[ ... ]

> diff --git a/arch/arm/boot/dts/ti/omap/omap4-l4.dtsi b/arch/arm/boot/dts/ti/omap/omap4-l4.dtsi
> index 4c78a0b28fab3..c1afc49f456cf 100644
> --- a/arch/arm/boot/dts/ti/omap/omap4-l4.dtsi
> +++ b/arch/arm/boot/dts/ti/omap/omap4-l4.dtsi
> @@ -681,7 +681,7 @@ omap4_pmx_core: pinmux@40 {
>  			};
>  
>  			omap4_padconf_global: omap4_padconf_global@5a0 {
> -				compatible = "syscon",
> +				compatible = "ti,omap4-sysc-padconf-global", "syscon",
>  					     "simple-bus";
>  				reg = <0x5a0 0x170>;
>  				#address-cells = <1>;

[Severity: Medium]
Similarly, arch/arm/boot/dts/ti/omap/omap4-l4.dtsi appears to retain
a standalone "syscon" compatible in its scm_conf@0 node:

				scm_conf: scm_conf@0 {
					compatible = "syscon";
					reg = <0x0 0x800>;

This same pattern of skipped nodes appears in
arch/arm/boot/dts/ti/omap/omap5-l4.dtsi (scm_conf@0) and the sibling file
arch/arm/boot/dts/ti/omap/omap2420.dtsi (scm_conf@270).

Should these nodes also be updated to fully comply with the
writing-bindings.rst requirements?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260608-n-dt-bindings-simple-bus-syscon-v3-0-4eba9ec1212a@oss.qualcomm.com?part=3

Re: [PATCH v3 3/3] ARM: dts: ti: Add specific compatibles for SCM conf nodes

[Conor Dooley]

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Reviewed-by: Conor Dooley <conor.dooley@microchip.com>


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