[PATCH v3 0/2] dt-bindings: mmc: st,sdhci: convert STMicroelectronics SDHCI-ST MMC/SD Controller controller binding to YAML

[PATCH v3 0/2] dt-bindings: mmc: st,sdhci: convert STMicroelectronics SDHCI-ST MMC/SD Controller controller binding to YAML

[Charan Pedumuru]

This patch series converts the legacy text-based Device Tree binding for
STMicroelectronics SDHCI-ST MMC/SD controller to DT schema (YAML) format.

Note:
The patch "dt-bindings: mmc: st,sdhci: convert to DT schema"
depends on the patch "arm: dts: st: align node patterns with established
convention". If the DT schema patch is applied before the DTS
cleanup patch, `dtbs_check` will fail due to the presence of the removed
properties in the existing DTS.

Signed-off-by: Charan Pedumuru <charan.pedumuru@gmail.com>
---
Changes in v3:
- st,sdhci: Edit description of reg property. Modify reg-names. Add
  "minItems" for clocks and clock-names properties.
- Modify the commit message to match with the updated changes.
- Link to v2: https://patch.msgid.link/20260503-st-mmc-v2-0-11ae3216d2ce@gmail.com

Changes in v2:
- Fix node name in DTS for the MMC to match with the estableshed convention.
- st,sdhci: drop unnecessary properties, modify "reg", "reg-names" and
  "clock-names" properties, include an allOf with $ref to mmc-controller.
- Link to v1: https://patch.msgid.link/20260409-st-mmc-v1-1-4c54321c3535@gmail.com

---
Charan Pedumuru (2):
      arm: dts: st: align node patterns with established convention
      dt-bindings: mmc: st,sdhci: convert to DT schema

 Documentation/devicetree/bindings/mmc/sdhci-st.txt | 110 ---------------------
 .../devicetree/bindings/mmc/st,sdhci.yaml          |  91 +++++++++++++++++
 arch/arm/boot/dts/st/stih407-family.dtsi           |   4 +-
 3 files changed, 93 insertions(+), 112 deletions(-)
---
base-commit: cf2cd8efd046c561191b8541d32a8bfe845bf06b
change-id: 20260327-st-mmc-c906ad95ff83

Best regards,
--  
Charan Pedumuru <charan.pedumuru@gmail.com>

[PATCH v3 1/2] arm: dts: st: align node patterns with established convention

[Charan Pedumuru]

Update ST MMC DTS node patterns to match established convention.

Signed-off-by: Charan Pedumuru <charan.pedumuru@gmail.com>
---
 arch/arm/boot/dts/st/stih407-family.dtsi | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/dts/st/stih407-family.dtsi b/arch/arm/boot/dts/st/stih407-family.dtsi
index 3e6a0542e3ae..08acba209c56 100644
--- a/arch/arm/boot/dts/st/stih407-family.dtsi
+++ b/arch/arm/boot/dts/st/stih407-family.dtsi
@@ -596,7 +596,7 @@ spi@9542000 {
 			status = "disabled";
 		};
 
-		mmc0: sdhci@9060000 {
+		mmc0: mmc@9060000 {
 			compatible = "st,sdhci-stih407", "st,sdhci";
 			status = "disabled";
 			reg = <0x09060000 0x7ff>, <0x9061008 0x20>;
@@ -611,7 +611,7 @@ mmc0: sdhci@9060000 {
 			bus-width = <8>;
 		};
 
-		mmc1: sdhci@9080000 {
+		mmc1: mmc@9080000 {
 			compatible = "st,sdhci-stih407", "st,sdhci";
 			status = "disabled";
 			reg = <0x09080000 0x7ff>;

-- 
2.54.0

Re: [PATCH v3 1/2] arm: dts: st: align node patterns with established convention

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Renaming `sdhci` nodes to `mmc` in `stih407-family.dtsi` breaks node overrides in dependent device trees, causing MMC controllers to become non-functional.
--

commit 874b7326db9041ff83194d41b493b257577ea261
Author: Charan Pedumuru <charan.pedumuru@gmail.com>

arm: dts: st: align node patterns with established convention

This commit updates the device tree node patterns for ST MMC controllers to
match established conventions by renaming the sdhci nodes to mmc.

> diff --git a/arch/arm/boot/dts/st/stih407-family.dtsi b/arch/arm/boot/dts/st/stih407-family.dtsi
> index 3e6a0542e3aea..08acba209c564 100644
> --- a/arch/arm/boot/dts/st/stih407-family.dtsi
> +++ b/arch/arm/boot/dts/st/stih407-family.dtsi
> @@ -596,7 +596,7 @@ spi@9542000 {
>  			status = "disabled";
>  		};
>  
> -		mmc0: sdhci@9060000 {
> +		mmc0: mmc@9060000 {

Does this rename break device tree overrides in dependent files like
stih418-b2199.dts and stih410-b2260.dts?

If dependent board files override properties by reopening the nodes using
their exact path and old names (e.g., soc { mmc0: sdhci@9060000 { ... }; }),
changing the base node name here to mmc@9060000 will cause the device tree
compiler to create a new parallel node instead of merging the properties.

The original mmc@9060000 node would remain disabled, and the newly created
sdhci@9060000 node would lack the required compatible, reg, and interrupts
properties, which could prevent the MMC driver from probing correctly.

>  			compatible = "st,sdhci-stih407", "st,sdhci";
>  			status = "disabled";
>  			reg = <0x09060000 0x7ff>, <0x9061008 0x20>;

[ ... ]

> -		mmc1: sdhci@9080000 {
> +		mmc1: mmc@9080000 {

Could this node rename also cause similar override failures for dependent
files that override mmc1?

>  			compatible = "st,sdhci-stih407", "st,sdhci";
>  			status = "disabled";
>  			reg = <0x09080000 0x7ff>;

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260508-st-mmc-v3-0-81c329ed28e8@gmail.com?part=1

[PATCH v3 2/2] dt-bindings: mmc: st,sdhci: convert to DT schema

[Charan Pedumuru]

Convert STMicroelectronics sdhci-st MMC/SD controller binding to DT schema.
Changes during conversion:
- In the legacy text binding, 'icn' was optional. Keep the clock list
  flexible to preserve compatibility, although all existing in-tree DTS
  files already provide both clocks.
- Document the optional "top-mmc-delay" register region and corresponding
  reg-name in the YAML binding, as existing in-tree DTS files already use
  both "mmc" and "top-mmc-delay" entries.

Signed-off-by: Charan Pedumuru <charan.pedumuru@gmail.com>
---
 Documentation/devicetree/bindings/mmc/sdhci-st.txt | 110 ---------------------
 .../devicetree/bindings/mmc/st,sdhci.yaml          |  91 +++++++++++++++++
 2 files changed, 91 insertions(+), 110 deletions(-)

diff --git a/Documentation/devicetree/bindings/mmc/sdhci-st.txt b/Documentation/devicetree/bindings/mmc/sdhci-st.txt
deleted file mode 100644
index ccf82b4ee838..000000000000
--- a/Documentation/devicetree/bindings/mmc/sdhci-st.txt
+++ /dev/null
@@ -1,110 +0,0 @@
-* STMicroelectronics sdhci-st MMC/SD controller
-
-This file documents the differences between the core properties in
-Documentation/devicetree/bindings/mmc/mmc.txt and the properties
-used by the sdhci-st driver.
-
-Required properties:
-- compatible:		Must be "st,sdhci" and it can be compatible to "st,sdhci-stih407"
-			to set the internal glue logic used for configuring the MMC
-			subsystem (mmcss) inside the FlashSS (available in STiH407 SoC
-			family).
-
-- clock-names:		Should be "mmc" and "icn".  (NB: The latter is not compulsory)
-			See: Documentation/devicetree/bindings/resource-names.txt
-- clocks:		Phandle to the clock.
-			See: Documentation/devicetree/bindings/clock/clock-bindings.txt
-
-- interrupts:		One mmc interrupt should be described here.
-- interrupt-names:	Should be "mmcirq".
-
-- pinctrl-names:	A pinctrl state names "default" must be defined.
-- pinctrl-0:		Phandle referencing pin configuration of the sd/emmc controller.
-			See: Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
-
-- reg:			This must provide the host controller base address and it can also
-			contain the FlashSS Top register for TX/RX delay used by the driver
-			to configure DLL inside the flashSS, if so reg-names must also be
-			specified.
-
-Optional properties:
-- reg-names:		Should be "mmc" and "top-mmc-delay". "top-mmc-delay" is optional
-			for eMMC on stih407 family silicon to configure DLL inside FlashSS.
-
-- non-removable:	Non-removable slot. Also used for configuring mmcss in STiH407 SoC
-			family.
-			See:  Documentation/devicetree/bindings/mmc/mmc.txt.
-
-- bus-width:		Number of data lines.
-			See:  Documentation/devicetree/bindings/mmc/mmc.txt.
-
-- max-frequency:	Can be 200MHz, 100MHz or 50MHz (default) and used for
-			configuring the CCONFIG3 in the mmcss.
-			See:  Documentation/devicetree/bindings/mmc/mmc.txt.
-
-- resets:		Phandle and reset specifier pair to softreset line of HC IP.
-			See: Documentation/devicetree/bindings/reset/reset.txt
-
-- vqmmc-supply:		Phandle to the regulator dt node, mentioned as the vcc/vdd
-			supply in eMMC/SD specs.
-
-- sd-uhs-sdr50:	To enable the SDR50 in the mmcss.
-			See:  Documentation/devicetree/bindings/mmc/mmc.txt.
-
-- sd-uhs-sdr104:	To enable the SDR104 in the mmcss.
-			See:  Documentation/devicetree/bindings/mmc/mmc.txt.
-
-- sd-uhs-ddr50:		To enable the DDR50 in the mmcss.
-			See:  Documentation/devicetree/bindings/mmc/mmc.txt.
-
-Example:
-
-/* Example stih416e eMMC configuration */
-
-mmc0: sdhci@fe81e000 {
-	compatible	= "st,sdhci";
-	reg		= <0xfe81e000 0x1000>;
-	interrupts	= <GIC_SPI 127 IRQ_TYPE_NONE>;
-	interrupt-names	= "mmcirq";
-	pinctrl-names	= "default";
-	pinctrl-0	= <&pinctrl_mmc0>;
-	clock-names	= "mmc";
-	clocks		= <&clk_s_a1_ls 1>;
-	bus-width	= <8>
-
-/* Example SD stih407 family configuration */
-
-mmc1: sdhci@9080000 {
-	compatible	= "st,sdhci-stih407", "st,sdhci";
-	reg		= <0x09080000 0x7ff>;
-	reg-names	= "mmc";
-	interrupts	= <GIC_SPI 90 IRQ_TYPE_NONE>;
-	interrupt-names	= "mmcirq";
-	pinctrl-names	= "default";
-	pinctrl-0	= <&pinctrl_sd1>;
-	clock-names	= "mmc";
-	clocks		= <&clk_s_c0_flexgen CLK_MMC_1>;
-	resets		= <&softreset STIH407_MMC1_SOFTRESET>;
-	bus-width	= <4>;
-};
-
-/* Example eMMC stih407 family configuration */
-
-mmc0: sdhci@9060000 {
-	compatible	= "st,sdhci-stih407", "st,sdhci";
-	reg		= <0x09060000 0x7ff>, <0x9061008 0x20>;
-	reg-names	= "mmc", "top-mmc-delay";
-	interrupts	= <GIC_SPI 92 IRQ_TYPE_NONE>;
-	interrupt-names	= "mmcirq";
-	pinctrl-names	= "default";
-	pinctrl-0	= <&pinctrl_mmc0>;
-	clock-names	= "mmc";
-	clocks		= <&clk_s_c0_flexgen CLK_MMC_0>;
-	vqmmc-supply	= <&vmmc_reg>;
-	max-frequency	= <200000000>;
-	bus-width	= <8>;
-	non-removable;
-	sd-uhs-sdr50;
-	sd-uhs-sdr104;
-	sd-uhs-ddr50;
-};
diff --git a/Documentation/devicetree/bindings/mmc/st,sdhci.yaml b/Documentation/devicetree/bindings/mmc/st,sdhci.yaml
new file mode 100644
index 000000000000..10e0e1ee6d5c
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/st,sdhci.yaml
@@ -0,0 +1,91 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mmc/st,sdhci.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: STMicroelectronics SDHCI-ST MMC/SD Controller
+
+description:
+  The STMicroelectronics SDHCI-ST MMC/SD host controller, which is
+  compliant with the SD Host Controller Interface (SDHCI) specification and
+  is used to interface with MMC, SD and SDIO cards. The ST SDHCI controller
+  extends the standard SDHCI capabilities with platform-specific
+  configurations such as additional register regions,clock inputs, and delay
+  control mechanisms required for signal timing adjustments which are
+  necessary to support high-speed modes and ensure reliable data transfer
+  across different ST SoCs.
+
+allOf:
+  - $ref: mmc-controller.yaml#
+
+maintainers:
+  - Peter Griffin <peter.griffin@linaro.org>
+
+properties:
+  compatible:
+    oneOf:
+      - const: st,sdhci
+      - items:
+          - const: st,sdhci-stih407
+          - const: st,sdhci
+
+  reg:
+    minItems: 1
+    items:
+      - description: MMC controller registers
+      - description: MMC delay/auxiliary registers
+
+  reg-names:
+    items:
+      - const: mmc
+      - const: top-mmc-delay
+
+  clocks:
+    minItems: 1
+    items:
+      - description: Clock for the MMC controller
+      - description: Interconnect (ICN) clock
+
+  clock-names:
+    items:
+      - const: mmc
+      - const: icn
+
+  interrupts:
+    maxItems: 1
+
+  interrupt-names:
+    const: mmcirq
+
+  resets:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - interrupts
+  - interrupt-names
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/clock/stih407-clks.h>
+    mmc@9060000 {
+        compatible = "st,sdhci-stih407", "st,sdhci";
+        reg = <0x09060000 0x7ff>, <0x9061008 0x20>;
+        reg-names = "mmc", "top-mmc-delay";
+        interrupts = <GIC_SPI 92 IRQ_TYPE_LEVEL_HIGH>;
+        interrupt-names = "mmcirq";
+        pinctrl-names = "default";
+        pinctrl-0 = <&pinctrl_mmc0>;
+        clock-names = "mmc", "icn";
+        clocks = <&clk_s_c0_flexgen CLK_MMC_0>,
+                 <&clk_s_c0_flexgen CLK_RX_ICN_HVA>;
+        bus-width = <8>;
+    };
+...

-- 
2.54.0

Re: [PATCH v3 2/2] dt-bindings: mmc: st,sdhci: convert to DT schema

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Missing `minItems: 1` for `clock-names` and `reg-names` restricts them to exactly two items, breaking schema validation for existing device trees.
--

commit 66ec88f9e00b102af921864d0e0bf8b1b9e7f38d
Author: Charan Pedumuru <charan.pedumuru@gmail.com>
dt-bindings: mmc: st,sdhci: convert to DT schema

This commit converts the STMicroelectronics sdhci-st MMC/SD controller
binding to DT schema. It updates the clock and register properties to
support backward compatibility for single-item entries.

>     - In the legacy text binding, 'icn' was optional. Keep the clock list
>       flexible to preserve compatibility, although all existing in-tree DTS
>       files already provide both clocks.
>     - Document the optional "top-mmc-delay" register region and corresponding
>       reg-name in the YAML binding, as existing in-tree DTS files already use
>       both "mmc" and "top-mmc-delay" entries.

Are these descriptions accurate regarding all existing in-tree DTS files?

In arch/arm/boot/dts/st/stih407-family.dtsi, the mmc1 node defines only a
single register name (reg-names = "mmc"). Other device trees such as
arch/powerpc/boot/dts/fsp2.dts also define a single clock and register.

> diff --git a/Documentation/devicetree/bindings/mmc/st,sdhci.yaml b/Documentation/devicetree/bindings/mmc/st,sdhci.yaml
> new file mode 100644
> index 0000000000000..10e0e1ee6d5cd
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mmc/st,sdhci.yaml

[ ... ]

> +  reg:
> +    minItems: 1
> +    items:
> +      - description: MMC controller registers
> +      - description: MMC delay/auxiliary registers
> +
> +  reg-names:
> +    items:
> +      - const: mmc
> +      - const: top-mmc-delay

Because items lists without an explicit minItems default to the length of
the list, does this strictly require two items for reg-names?

Will this cause make dtbs_check to fail for existing nodes like mmc1 that
only provide "mmc"? Should minItems: 1 be added here to allow single entries?

[ ... ]

> +  clocks:
> +    minItems: 1
> +    items:
> +      - description: Clock for the MMC controller
> +      - description: Interconnect (ICN) clock
> +
> +  clock-names:
> +    items:
> +      - const: mmc
> +      - const: icn

Similarly, does clock-names require minItems: 1 to match the flexibility
added to the clocks property and prevent schema validation errors on
single-clock configurations?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260508-st-mmc-v3-0-81c329ed28e8@gmail.com?part=2

Re: [PATCH v3 2/2] dt-bindings: mmc: st,sdhci: convert to DT schema

[Charan Pedumuru]

On 09-05-2026 03:52, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Medium] Missing `minItems: 1` for `clock-names` and `reg-names` restricts them to exactly two items, breaking schema validation for existing device trees.
> --
> 
> commit 66ec88f9e00b102af921864d0e0bf8b1b9e7f38d
> Author: Charan Pedumuru <charan.pedumuru@gmail.com>
> dt-bindings: mmc: st,sdhci: convert to DT schema
> 
> This commit converts the STMicroelectronics sdhci-st MMC/SD controller
> binding to DT schema. It updates the clock and register properties to
> support backward compatibility for single-item entries.
> 
>>     - In the legacy text binding, 'icn' was optional. Keep the clock list
>>       flexible to preserve compatibility, although all existing in-tree DTS
>>       files already provide both clocks.
>>     - Document the optional "top-mmc-delay" register region and corresponding
>>       reg-name in the YAML binding, as existing in-tree DTS files already use
>>       both "mmc" and "top-mmc-delay" entries.
> 
> Are these descriptions accurate regarding all existing in-tree DTS files?

Yes

> 
> In arch/arm/boot/dts/st/stih407-family.dtsi, the mmc1 node defines only a
> single register name (reg-names = "mmc"). Other device trees such as
> arch/powerpc/boot/dts/fsp2.dts also define a single clock and register.
> 
>> diff --git a/Documentation/devicetree/bindings/mmc/st,sdhci.yaml b/Documentation/devicetree/bindings/mmc/st,sdhci.yaml
>> new file mode 100644
>> index 0000000000000..10e0e1ee6d5cd
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/mmc/st,sdhci.yaml
> 
> [ ... ]
> 
>> +  reg:
>> +    minItems: 1
>> +    items:
>> +      - description: MMC controller registers
>> +      - description: MMC delay/auxiliary registers
>> +
>> +  reg-names:
>> +    items:
>> +      - const: mmc
>> +      - const: top-mmc-delay
> 
> Because items lists without an explicit minItems default to the length of
> the list, does this strictly require two items for reg-names?

Yes, but I can add minItems as 1 to accept the nodes that define only 1 reg-names. but the existing DTS uses both.

> 
> Will this cause make dtbs_check to fail for existing nodes like mmc1 that
> only provide "mmc"? Should minItems: 1 be added here to allow single entries?

Yes, I will add minItmes to allow singe entries.

> 
> [ ... ]
> 
>> +  clocks:
>> +    minItems: 1
>> +    items:
>> +      - description: Clock for the MMC controller
>> +      - description: Interconnect (ICN) clock
>> +
>> +  clock-names:
>> +    items:
>> +      - const: mmc
>> +      - const: icn
> 
> Similarly, does clock-names require minItems: 1 to match the flexibility
> added to the clocks property and prevent schema validation errors on
> single-clock configurations?

I can add minItmes as 1 if the node only requires 1 clock, but the current DTS uses both of them.

> 

-- 
Best Regards,
Charan.