[PATCH 0/3] Add GPADC support for A523

[PATCH 0/3] Add GPADC support for A523

[Michal Piekos]

Add support for Allwinner A523 GPADC in sun20i gpadc driver and describe
corresponding node in dts for A523 SoC.

A523 uses same model as existing driver except it has two clocks.

Added support to enable more than one clock in the driver, extended the
binding with new compatible and wired up dts node for A523 which uses D1
as fallback compatible.

Signed-off-by: Michal Piekos <michal.piekos@mmpsystems.pl>
---
Michal Piekos (3):
      dt-bindings: iio: adc: Add GPADC for Allwinner A523
      iio: adc: sun20i-gpadc: add A523 gpadc support
      arm64: dts: allwinner: a523: add gpadc node

 .../iio/adc/allwinner,sun20i-d1-gpadc.yaml         | 37 +++++++++++++++++++++-
 arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi     | 12 +++++++
 drivers/iio/adc/sun20i-gpadc-iio.c                 |  8 ++---
 3 files changed, 52 insertions(+), 5 deletions(-)
---
base-commit: 8ab992f815d6736b5c7a6f5fd7bfe7bc106bb3dc
change-id: 20260507-sunxi-a523-gpadc-1879aa5df754

Best regards,
--  
Michal Piekos <michal.piekos@mmpsystems.pl>

[PATCH 1/3] dt-bindings: iio: adc: Add GPADC for Allwinner A523

[Michal Piekos]

Add support for the GPADC for the Allwinner A523. It differs from the
D1/T113s/R329/T507 by having two clocks.

Signed-off-by: Michal Piekos <michal.piekos@mmpsystems.pl>
---
 .../iio/adc/allwinner,sun20i-d1-gpadc.yaml         | 37 +++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml b/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml
index da605a051b94..89da96cd705f 100644
--- a/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml
+++ b/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml
@@ -17,6 +17,7 @@ properties:
       - items:
           - enum:
               - allwinner,sun50i-h616-gpadc
+              - allwinner,sun55i-a523-gpadc
           - const: allwinner,sun20i-d1-gpadc
 
   "#io-channel-cells":
@@ -29,7 +30,12 @@ properties:
     const: 0
 
   clocks:
-    maxItems: 1
+    minItems: 1
+    maxItems: 2
+
+  clock-names:
+    minItems: 1
+    maxItems: 2
 
   interrupts:
     maxItems: 1
@@ -40,6 +46,35 @@ properties:
   resets:
     maxItems: 1
 
+allOf:
+  - if:
+      properties:
+        compatible:
+          items:
+            - const: allwinner,sun55i-a523-gpadc
+            - const: allwinner,sun20i-d1-gpadc
+    then:
+      properties:
+        clocks:
+          minItems: 2
+          maxItems: 2
+          items:
+            - description: Bus clock
+            - description: Module clock
+        clock-names:
+          minItems: 2
+          maxItems: 2
+          items:
+            - const: bus
+            - const: mod
+      required:
+        - clock-names
+    else:
+      properties:
+        clocks:
+          maxItems: 1
+        clock-names: false
+
 patternProperties:
   "^channel@[0-9a-f]+$":
     $ref: adc.yaml

-- 
2.43.0

[PATCH 2/3] iio: adc: sun20i-gpadc: add A523 gpadc support

[Michal Piekos]

A523 differs from existing sun20i-gpadc-iio by having two clocks; bus
clock and module clock.

Change driver to enable all clocks.

Signed-off-by: Michal Piekos <michal.piekos@mmpsystems.pl>
---
 drivers/iio/adc/sun20i-gpadc-iio.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/adc/sun20i-gpadc-iio.c b/drivers/iio/adc/sun20i-gpadc-iio.c
index 861c14da75ad..dd4c7e6e3d76 100644
--- a/drivers/iio/adc/sun20i-gpadc-iio.c
+++ b/drivers/iio/adc/sun20i-gpadc-iio.c
@@ -180,7 +180,7 @@ static int sun20i_gpadc_probe(struct platform_device *pdev)
 	struct iio_dev *indio_dev;
 	struct sun20i_gpadc_iio *info;
 	struct reset_control *rst;
-	struct clk *clk;
+	struct clk_bulk_data *clks;
 	int irq;
 	int ret;
 
@@ -205,9 +205,9 @@ static int sun20i_gpadc_probe(struct platform_device *pdev)
 	if (IS_ERR(info->regs))
 		return PTR_ERR(info->regs);
 
-	clk = devm_clk_get_enabled(dev, NULL);
-	if (IS_ERR(clk))
-		return dev_err_probe(dev, PTR_ERR(clk), "failed to enable bus clock\n");
+	ret = devm_clk_bulk_get_all_enabled(dev, &clks);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "failed to enable clocks\n");
 
 	rst = devm_reset_control_get_exclusive(dev, NULL);
 	if (IS_ERR(rst))

-- 
2.43.0

[PATCH 3/3] arm64: dts: allwinner: a523: add gpadc node

[Michal Piekos]

Describe high speed timer block on Allwinner D1S-T113.

Tested on Radxa Cubie A5E:
- 2 connected channels are showing voltages in agreement with
  schematics.
        BOOT-SEL-ADC ~500mV
        BOM-ADC ~1800mV
- 3rd channel exposed on 40pin header is showing correct voltages when
  connected to known voltage source.

Signed-off-by: Michal Piekos <michal.piekos@mmpsystems.pl>
---
 arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi b/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi
index 5afa8d92acbf..f6c5cae5b23a 100644
--- a/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi
+++ b/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi
@@ -340,6 +340,18 @@ ledc: led-controller@2008000 {
 			status = "disabled";
 		};
 
+		gpadc: adc@2009000 {
+			compatible = "allwinner,sun55i-a523-gpadc",
+				     "allwinner,sun20i-d1-gpadc";
+			reg = <0x2009000 0x400>;
+			clocks = <&ccu CLK_BUS_GPADC0>, <&ccu CLK_GPADC0>;
+			clock-names = "bus", "mod";
+			resets = <&ccu RST_BUS_GPADC0>;
+			interrupts = <GIC_SPI 61 IRQ_TYPE_LEVEL_HIGH>;
+			status = "disabled";
+			#io-channel-cells = <1>;
+		};
+
 		wdt: watchdog@2050000 {
 			compatible = "allwinner,sun55i-a523-wdt";
 			reg = <0x2050000 0x20>;

-- 
2.43.0

Re: [PATCH 1/3] dt-bindings: iio: adc: Add GPADC for Allwinner A523

[Rob Herring (Arm)]

On Sun, 10 May 2026 14:57:22 +0200, Michal Piekos wrote:
> Add support for the GPADC for the Allwinner A523. It differs from the
> D1/T113s/R329/T507 by having two clocks.
> 
> Signed-off-by: Michal Piekos <michal.piekos@mmpsystems.pl>
> ---
>  .../iio/adc/allwinner,sun20i-d1-gpadc.yaml         | 37 +++++++++++++++++++++-
>  1 file changed, 36 insertions(+), 1 deletion(-)
> 

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml: allOf:0:then:properties:clocks: {'minItems': 2, 'maxItems': 2, 'items': [{'description': 'Bus clock'}, {'description': 'Module clock'}]} should not be valid under {'required': ['maxItems']}
	hint: "maxItems" is not needed with an "items" list
	from schema $id: http://devicetree.org/meta-schemas/items.yaml
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml: allOf:0:then:properties:clocks: 'oneOf' conditional failed, one must be fixed:
	False schema does not allow 2
	[{'description': 'Bus clock'}, {'description': 'Module clock'}] is too long
	[{'description': 'Bus clock'}, {'description': 'Module clock'}] is too short
	1 was expected
	hint: "minItems" is only needed if less than the "items" list length
	from schema $id: http://devicetree.org/meta-schemas/items.yaml
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml: allOf:0:then:properties:clock-names: {'minItems': 2, 'maxItems': 2, 'items': [{'const': 'bus'}, {'const': 'mod'}]} should not be valid under {'required': ['maxItems']}
	hint: "maxItems" is not needed with an "items" list
	from schema $id: http://devicetree.org/meta-schemas/items.yaml
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml: allOf:0:then:properties:clock-names: 'oneOf' conditional failed, one must be fixed:
	False schema does not allow 2
	[{'const': 'bus'}, {'const': 'mod'}] is too long
	[{'const': 'bus'}, {'const': 'mod'}] is too short
	1 was expected
	hint: "minItems" is only needed if less than the "items" list length
	from schema $id: http://devicetree.org/meta-schemas/items.yaml

doc reference errors (make refcheckdocs):

See https://patchwork.kernel.org/project/devicetree/patch/20260510-sunxi-a523-gpadc-v1-1-4f6b0f4000fb@mmpsystems.pl

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.

Re: [PATCH 3/3] arm64: dts: allwinner: a523: add gpadc node

[Jernej Škrabec]

Dne nedelja, 10. maj 2026 ob 14:57:24 Srednjeevropski poletni čas je Michal Piekos napisal(a):
> Describe high speed timer block on Allwinner D1S-T113.

Above line doesn't make much sense.

Best regards,
Jernej

> 
> Tested on Radxa Cubie A5E:
> - 2 connected channels are showing voltages in agreement with
>   schematics.
>         BOOT-SEL-ADC ~500mV
>         BOM-ADC ~1800mV
> - 3rd channel exposed on 40pin header is showing correct voltages when
>   connected to known voltage source.
> 
> Signed-off-by: Michal Piekos <michal.piekos@mmpsystems.pl>
> ---
>  arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi b/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi
> index 5afa8d92acbf..f6c5cae5b23a 100644
> --- a/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi
> +++ b/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi
> @@ -340,6 +340,18 @@ ledc: led-controller@2008000 {
>  			status = "disabled";
>  		};
>  
> +		gpadc: adc@2009000 {
> +			compatible = "allwinner,sun55i-a523-gpadc",
> +				     "allwinner,sun20i-d1-gpadc";
> +			reg = <0x2009000 0x400>;
> +			clocks = <&ccu CLK_BUS_GPADC0>, <&ccu CLK_GPADC0>;
> +			clock-names = "bus", "mod";
> +			resets = <&ccu RST_BUS_GPADC0>;
> +			interrupts = <GIC_SPI 61 IRQ_TYPE_LEVEL_HIGH>;
> +			status = "disabled";
> +			#io-channel-cells = <1>;
> +		};
> +
>  		wdt: watchdog@2050000 {
>  			compatible = "allwinner,sun55i-a523-wdt";
>  			reg = <0x2050000 0x20>;
> 
> 

Re: [PATCH 1/3] dt-bindings: iio: adc: Add GPADC for Allwinner A523

[Jernej Škrabec]

Dne nedelja, 10. maj 2026 ob 14:57:22 Srednjeevropski poletni čas je Michal Piekos napisal(a):
> Add support for the GPADC for the Allwinner A523. It differs from the
> D1/T113s/R329/T507 by having two clocks.
> 
> Signed-off-by: Michal Piekos <michal.piekos@mmpsystems.pl>
> ---
>  .../iio/adc/allwinner,sun20i-d1-gpadc.yaml         | 37 +++++++++++++++++++++-
>  1 file changed, 36 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml b/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml
> index da605a051b94..89da96cd705f 100644
> --- a/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml
> +++ b/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml
> @@ -17,6 +17,7 @@ properties:
>        - items:
>            - enum:
>                - allwinner,sun50i-h616-gpadc
> +              - allwinner,sun55i-a523-gpadc

It shouldn't be combined if it has different number of clocks.

Best regards,
Jernej

>            - const: allwinner,sun20i-d1-gpadc
>  
>    "#io-channel-cells":
> @@ -29,7 +30,12 @@ properties:
>      const: 0
>  
>    clocks:
> -    maxItems: 1
> +    minItems: 1
> +    maxItems: 2
> +
> +  clock-names:
> +    minItems: 1
> +    maxItems: 2
>  
>    interrupts:
>      maxItems: 1
> @@ -40,6 +46,35 @@ properties:
>    resets:
>      maxItems: 1
>  
> +allOf:
> +  - if:
> +      properties:
> +        compatible:
> +          items:
> +            - const: allwinner,sun55i-a523-gpadc
> +            - const: allwinner,sun20i-d1-gpadc
> +    then:
> +      properties:
> +        clocks:
> +          minItems: 2
> +          maxItems: 2
> +          items:
> +            - description: Bus clock
> +            - description: Module clock
> +        clock-names:
> +          minItems: 2
> +          maxItems: 2
> +          items:
> +            - const: bus
> +            - const: mod
> +      required:
> +        - clock-names
> +    else:
> +      properties:
> +        clocks:
> +          maxItems: 1
> +        clock-names: false
> +
>  patternProperties:
>    "^channel@[0-9a-f]+$":
>      $ref: adc.yaml
> 
> 

Re: [PATCH 3/3] arm64: dts: allwinner: a523: add gpadc node

[Chen-Yu Tsai]

On Sun, May 10, 2026 at 9:02 PM Michal Piekos
<michal.piekos@mmpsystems.pl> wrote:
>
> Describe high speed timer block on Allwinner D1S-T113.
>
> Tested on Radxa Cubie A5E:
> - 2 connected channels are showing voltages in agreement with
>   schematics.
>         BOOT-SEL-ADC ~500mV
>         BOM-ADC ~1800mV
> - 3rd channel exposed on 40pin header is showing correct voltages when
>   connected to known voltage source.
>
> Signed-off-by: Michal Piekos <michal.piekos@mmpsystems.pl>
> ---
>  arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi b/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi
> index 5afa8d92acbf..f6c5cae5b23a 100644
> --- a/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi
> +++ b/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi
> @@ -340,6 +340,18 @@ ledc: led-controller@2008000 {
>                         status = "disabled";
>                 };
>
> +               gpadc: adc@2009000 {
> +                       compatible = "allwinner,sun55i-a523-gpadc",
> +                                    "allwinner,sun20i-d1-gpadc";
> +                       reg = <0x2009000 0x400>;
> +                       clocks = <&ccu CLK_BUS_GPADC0>, <&ccu CLK_GPADC0>;
> +                       clock-names = "bus", "mod";
> +                       resets = <&ccu RST_BUS_GPADC0>;
> +                       interrupts = <GIC_SPI 61 IRQ_TYPE_LEVEL_HIGH>;
> +                       status = "disabled";
> +                       #io-channel-cells = <1>;

status should always be the last property.

> +               };
> +
>                 wdt: watchdog@2050000 {
>                         compatible = "allwinner,sun55i-a523-wdt";
>                         reg = <0x2050000 0x20>;
>
> --
> 2.43.0
>
>

Re: [PATCH 1/3] dt-bindings: iio: adc: Add GPADC for Allwinner A523

[Andre Przywara]

Hi Michal,

thanks for adding this!

On 5/10/26 14:57, Michal Piekos wrote:
> Add support for the GPADC for the Allwinner A523. It differs from the
> D1/T113s/R329/T507 by having two clocks.
> 
> Signed-off-by: Michal Piekos <michal.piekos@mmpsystems.pl>
> ---
>   .../iio/adc/allwinner,sun20i-d1-gpadc.yaml         | 37 +++++++++++++++++++++-
>   1 file changed, 36 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml b/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml
> index da605a051b94..89da96cd705f 100644
> --- a/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml
> +++ b/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml
> @@ -17,6 +17,7 @@ properties:
>         - items:
>             - enum:
>                 - allwinner,sun50i-h616-gpadc
> +              - allwinner,sun55i-a523-gpadc
>             - const: allwinner,sun20i-d1-gpadc

As Jernej already mentioned, the A523 GPADC is not fully compatible, 
since it adds another clock. The question to ask is: Can a driver only 
knowing about the fallback device handle this new device? For which the 
answer here is: No, it misses a clock.
So add just a single entry for the A523 (plus adding it to the driver).

So looking at this I wonder if we should add some property to describe 
the number of supported channels, since they are slightly different 
between the SoCs:
- The D1 manual mentions 2 channels.
- The T113s manual (same die as the D1?) describes 1 channel only.
- The T507 manual (same die as the H616) reports 4 channels.
- The A733 has 6 channels.
- The A133 has 1 channel, but it's channel 1, not 0.

So all of this is somewhat covered as channels are described as child 
nodes, and have a reg property. Ideally non-existing channels just 
wouldn't be listed, but I don't know if we want to rely on that.

So I am wondering if we should introduce a limit, or rather a mask (to 
cover the A133 oddity)?
Either a DT property (channel-mask, as a single sell representing the 
bit mask), or derived in the driver from the compatible string.
The former would avoid introducing different compatible strings just 
because of that, though I think this type of property is somewhat 
discouraged?

Any thoughts?

>   
>     "#io-channel-cells":
> @@ -29,7 +30,12 @@ properties:
>       const: 0
>   
>     clocks:
> -    maxItems: 1
> +    minItems: 1
> +    maxItems: 2
> +
> +  clock-names:
> +    minItems: 1
> +    maxItems: 2
>   
>     interrupts:
>       maxItems: 1
> @@ -40,6 +46,35 @@ properties:
>     resets:
>       maxItems: 1
>   
> +allOf:
> +  - if:
> +      properties:
> +        compatible:
> +          items:
> +            - const: allwinner,sun55i-a523-gpadc
> +            - const: allwinner,sun20i-d1-gpadc
> +    then:
> +      properties:
> +        clocks:
> +          minItems: 2
> +          maxItems: 2
> +          items:
> +            - description: Bus clock
> +            - description: Module clock

I am not a YAML expert, but I think you can drop the min and max 
properties, if you just enumerate the cases. Same for the names.

Cheers,
Andre

> +        clock-names:
> +          minItems: 2
> +          maxItems: 2
> +          items:
> +            - const: bus
> +            - const: mod
> +      required:
> +        - clock-names
> +    else:
> +      properties:
> +        clocks:
> +          maxItems: 1
> +        clock-names: false
> +
>   patternProperties:
>     "^channel@[0-9a-f]+$":
>       $ref: adc.yaml
> 

Re: [PATCH 1/3] dt-bindings: iio: adc: Add GPADC for Allwinner A523

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Incorrect fallback compatible string 'allwinner,sun20i-d1-gpadc' violating backward compatibility guarantees.
--

commit 48f3b1ab2ee7aee8d556d5b6595c00af83e47dad
Author: Michal Piekos <michal.piekos@mmpsystems.pl>

dt-bindings: iio: adc: Add GPADC for Allwinner A523

This commit adds device tree binding support for the GPADC on the Allwinner
A523. It updates the existing sun20i-d1-gpadc binding to accommodate the
A523's requirement for two separate clocks instead of one.

> diff --git a/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml b/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml
> index da605a051b949..89da96cd705f0 100644
> --- a/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml
> +++ b/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml
> @@ -17,6 +17,7 @@ properties:
>        - items:
>            - enum:
>                - allwinner,sun50i-h616-gpadc
> +              - allwinner,sun55i-a523-gpadc
>            - const: allwinner,sun20i-d1-gpadc

Since the A523 requires two clocks (bus and mod) and the D1 only requires
one, does using the D1 compatible as a fallback violate backward
compatibility guarantees?

If an older kernel boots with this new device tree, it will match the
allwinner,sun20i-d1-gpadc fallback and bind the legacy driver. The legacy
D1 driver only fetches and enables the first clock listed (the bus clock).

Will this leave the required mod clock disabled, causing the ADC hardware
reads to timeout? 

Should allwinner,sun55i-a523-gpadc be defined as a standalone compatible
string without a fallback instead?

[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260510-sunxi-a523-gpadc-v1-0-4f6b0f4000fb@mmpsystems.pl?part=1

Re: [PATCH 2/3] iio: adc: sun20i-gpadc: add A523 gpadc support

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Missing validation for 0 clocks returned by devm_clk_bulk_get_all_enabled() leading to a kernel panic on register access.
--

commit daf3632321b60ce8511b98ae1ad1e4b009e48e3c
Author: Michal Piekos <michal.piekos@mmpsystems.pl>

iio: adc: sun20i-gpadc: add A523 gpadc support

This commit adds support for the A523 gpadc by switching from a single
clock initialization to using devm_clk_bulk_get_all_enabled() to handle
both the bus and module clocks.

> diff --git a/drivers/iio/adc/sun20i-gpadc-iio.c b/drivers/iio/adc/sun20i-gpadc-iio.c
> index 861c14da75add..dd4c7e6e3d76e 100644
> --- a/drivers/iio/adc/sun20i-gpadc-iio.c
> +++ b/drivers/iio/adc/sun20i-gpadc-iio.c
[ ... ]
> @@ -205,9 +205,9 @@ static int sun20i_gpadc_probe(struct platform_device *pdev)
>  	if (IS_ERR(info->regs))
>  		return PTR_ERR(info->regs);
>  
> -	clk = devm_clk_get_enabled(dev, NULL);
> -	if (IS_ERR(clk))
> -		return dev_err_probe(dev, PTR_ERR(clk), "failed to enable bus clock\n");
> +	ret = devm_clk_bulk_get_all_enabled(dev, &clks);
> +	if (ret < 0)
> +		return dev_err_probe(dev, ret, "failed to enable clocks\n");

If the device tree node lacks clock definitions,
devm_clk_bulk_get_all_enabled() will return 0. Because this error handling
only checks for negative return values, could this allow the driver probe
to proceed with zero clocks enabled?

On Allwinner hardware, accessing the registers of an unclocked IP block
typically triggers a synchronous external abort or bus fault. If ret is 0,
the probe later performs a register write:

sun20i_gpadc_probe() {
    ...
	writel(FIELD_PREP(SUN20I_GPADC_CTRL_ADC_AUTOCALI_EN_MASK, 1) |
	       FIELD_PREP(SUN20I_GPADC_CTRL_WORK_MODE_MASK, SUN20I_GPADC_WORK_MODE_SINGLE),
	       info->regs + SUN20I_GPADC_CTRL);
    ...
}

Should we also verify that the number of clocks returned is greater than
zero to prevent a potential panic during the register configuration?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260510-sunxi-a523-gpadc-v1-0-4f6b0f4000fb@mmpsystems.pl?part=2

Re: [PATCH 3/3] arm64: dts: allwinner: a523: add gpadc node

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The commit message incorrectly describes the hardware change and target SoC.
--

commit 6c12757bc070dc9476878d0e08e22e28437d957d
Author: Michal Piekos <michal.piekos@mmpsystems.pl>

arm64: dts: allwinner: a523: add gpadc node

This commit adds the General Purpose ADC node to the Allwinner A523
device tree. It also documents successful voltage testing of the ADC
channels on the Radxa Cubie A5E board.

> Describe high speed timer block on Allwinner D1S-T113.

This isn't a bug in the device tree changes, but the commit description
appears to have a copy-paste error. The text mentions a high speed timer
block on the Allwinner D1S-T113, while the patch actually adds the gpadc
node for the sun55i-a523.

Could this description be updated to accurately reflect the gpadc addition?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260510-sunxi-a523-gpadc-v1-0-4f6b0f4000fb@mmpsystems.pl?part=3

Re: [PATCH 1/3] dt-bindings: iio: adc: Add GPADC for Allwinner A523

[Michal Piekos]

On Mon, May 11, 2026 at 06:02:16PM +0200, Andre Przywara wrote:
> Hi Michal,
> 
> thanks for adding this!
> 
> On 5/10/26 14:57, Michal Piekos wrote:
> > Add support for the GPADC for the Allwinner A523. It differs from the
> > D1/T113s/R329/T507 by having two clocks.
> > 
> > Signed-off-by: Michal Piekos <michal.piekos@mmpsystems.pl>
> > ---
> >   .../iio/adc/allwinner,sun20i-d1-gpadc.yaml         | 37 +++++++++++++++++++++-
> >   1 file changed, 36 insertions(+), 1 deletion(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml b/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml
> > index da605a051b94..89da96cd705f 100644
> > --- a/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml
> > +++ b/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml
> > @@ -17,6 +17,7 @@ properties:
> >         - items:
> >             - enum:
> >                 - allwinner,sun50i-h616-gpadc
> > +              - allwinner,sun55i-a523-gpadc
> >             - const: allwinner,sun20i-d1-gpadc
> 
> As Jernej already mentioned, the A523 GPADC is not fully compatible, since
> it adds another clock. The question to ask is: Can a driver only knowing
> about the fallback device handle this new device? For which the answer here
> is: No, it misses a clock.
> So add just a single entry for the A523 (plus adding it to the driver).
> 
> So looking at this I wonder if we should add some property to describe the
> number of supported channels, since they are slightly different between the
> SoCs:
> - The D1 manual mentions 2 channels.
> - The T113s manual (same die as the D1?) describes 1 channel only.
> - The T507 manual (same die as the H616) reports 4 channels.
> - The A733 has 6 channels.
> - The A133 has 1 channel, but it's channel 1, not 0.
> 
> So all of this is somewhat covered as channels are described as child nodes,
> and have a reg property. Ideally non-existing channels just wouldn't be
> listed, but I don't know if we want to rely on that.
> 
> So I am wondering if we should introduce a limit, or rather a mask (to cover
> the A133 oddity)?
> Either a DT property (channel-mask, as a single sell representing the bit
> mask), or derived in the driver from the compatible string.
> The former would avoid introducing different compatible strings just because
> of that, though I think this type of property is somewhat discouraged?
> 
> Any thoughts?

Thanks. I have missed that sparse channels are also possible. I think in
current implementation it will cause issue with lookup through
<&gpadc 1> as sun20i_gpadc_alloc_channels would effectively create
channels[0].channel = 1 in such scenario. I will try to verify if my
logic is correct and provide separate fix if needed.

Regarding DT property masking channels there is already precedence:
atmel,adc-channels-used is a bitmask of muxed and enabled channels.
Not sure if preferable though...

Michal
> 
> >     "#io-channel-cells":
> > @@ -29,7 +30,12 @@ properties:
> >       const: 0
> >     clocks:
> > -    maxItems: 1
> > +    minItems: 1
> > +    maxItems: 2
> > +
> > +  clock-names:
> > +    minItems: 1
> > +    maxItems: 2
> >     interrupts:
> >       maxItems: 1
> > @@ -40,6 +46,35 @@ properties:
> >     resets:
> >       maxItems: 1
> > +allOf:
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          items:
> > +            - const: allwinner,sun55i-a523-gpadc
> > +            - const: allwinner,sun20i-d1-gpadc
> > +    then:
> > +      properties:
> > +        clocks:
> > +          minItems: 2
> > +          maxItems: 2
> > +          items:
> > +            - description: Bus clock
> > +            - description: Module clock
> 
> I am not a YAML expert, but I think you can drop the min and max properties,
> if you just enumerate the cases. Same for the names.
> 
> Cheers,
> Andre

I will correct that in v2.
Michal.
> 
> > +        clock-names:
> > +          minItems: 2
> > +          maxItems: 2
> > +          items:
> > +            - const: bus
> > +            - const: mod
> > +      required:
> > +        - clock-names
> > +    else:
> > +      properties:
> > +        clocks:
> > +          maxItems: 1
> > +        clock-names: false
> > +
> >   patternProperties:
> >     "^channel@[0-9a-f]+$":
> >       $ref: adc.yaml
> > 
> 

Re: [PATCH 2/3] iio: adc: sun20i-gpadc: add A523 gpadc support

[Jonathan Cameron]

On Sun, 10 May 2026 14:57:23 +0200
Michal Piekos <michal.piekos@mmpsystems.pl> wrote:

> A523 differs from existing sun20i-gpadc-iio by having two clocks; bus
> clock and module clock.
> 
> Change driver to enable all clocks.
> 
> Signed-off-by: Michal Piekos <michal.piekos@mmpsystems.pl>
I'm expecting this to change given comment on not being quite compatible so
I'll wait for v2 before reviewing.

Thanks,

Jonathan

> ---
>  drivers/iio/adc/sun20i-gpadc-iio.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iio/adc/sun20i-gpadc-iio.c b/drivers/iio/adc/sun20i-gpadc-iio.c
> index 861c14da75ad..dd4c7e6e3d76 100644
> --- a/drivers/iio/adc/sun20i-gpadc-iio.c
> +++ b/drivers/iio/adc/sun20i-gpadc-iio.c
> @@ -180,7 +180,7 @@ static int sun20i_gpadc_probe(struct platform_device *pdev)
>  	struct iio_dev *indio_dev;
>  	struct sun20i_gpadc_iio *info;
>  	struct reset_control *rst;
> -	struct clk *clk;
> +	struct clk_bulk_data *clks;
>  	int irq;
>  	int ret;
>  
> @@ -205,9 +205,9 @@ static int sun20i_gpadc_probe(struct platform_device *pdev)
>  	if (IS_ERR(info->regs))
>  		return PTR_ERR(info->regs);
>  
> -	clk = devm_clk_get_enabled(dev, NULL);
> -	if (IS_ERR(clk))
> -		return dev_err_probe(dev, PTR_ERR(clk), "failed to enable bus clock\n");
> +	ret = devm_clk_bulk_get_all_enabled(dev, &clks);
> +	if (ret < 0)
> +		return dev_err_probe(dev, ret, "failed to enable clocks\n");
>  
>  	rst = devm_reset_control_get_exclusive(dev, NULL);
>  	if (IS_ERR(rst))
> 

Re: [PATCH 2/3] iio: adc: sun20i-gpadc: add A523 gpadc support

[Andre Przywara]

Hi,

On 5/12/26 13:51, Jonathan Cameron wrote:
> On Sun, 10 May 2026 14:57:23 +0200
> Michal Piekos <michal.piekos@mmpsystems.pl> wrote:
> 
>> A523 differs from existing sun20i-gpadc-iio by having two clocks; bus
>> clock and module clock.
>>
>> Change driver to enable all clocks.
>>
>> Signed-off-by: Michal Piekos <michal.piekos@mmpsystems.pl>
> I'm expecting this to change given comment on not being quite compatible so
> I'll wait for v2 before reviewing.

Yes, we need a v2, but just for adding the new compatible string. 
Otherwise I think this patch is a neat solution, because we don't need 
to further differentiate between the different SoC's number of required 
clocks.

Cheers,
Andre

> 
> Thanks,
> 
> Jonathan
> 
>> ---
>>   drivers/iio/adc/sun20i-gpadc-iio.c | 8 ++++----
>>   1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/iio/adc/sun20i-gpadc-iio.c b/drivers/iio/adc/sun20i-gpadc-iio.c
>> index 861c14da75ad..dd4c7e6e3d76 100644
>> --- a/drivers/iio/adc/sun20i-gpadc-iio.c
>> +++ b/drivers/iio/adc/sun20i-gpadc-iio.c
>> @@ -180,7 +180,7 @@ static int sun20i_gpadc_probe(struct platform_device *pdev)
>>   	struct iio_dev *indio_dev;
>>   	struct sun20i_gpadc_iio *info;
>>   	struct reset_control *rst;
>> -	struct clk *clk;
>> +	struct clk_bulk_data *clks;
>>   	int irq;
>>   	int ret;
>>   
>> @@ -205,9 +205,9 @@ static int sun20i_gpadc_probe(struct platform_device *pdev)
>>   	if (IS_ERR(info->regs))
>>   		return PTR_ERR(info->regs);
>>   
>> -	clk = devm_clk_get_enabled(dev, NULL);
>> -	if (IS_ERR(clk))
>> -		return dev_err_probe(dev, PTR_ERR(clk), "failed to enable bus clock\n");
>> +	ret = devm_clk_bulk_get_all_enabled(dev, &clks);
>> +	if (ret < 0)
>> +		return dev_err_probe(dev, ret, "failed to enable clocks\n");
>>   
>>   	rst = devm_reset_control_get_exclusive(dev, NULL);
>>   	if (IS_ERR(rst))
>>
> 
>