[PATCH v2 0/3] Add GPADC support for A523

[PATCH v2 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 as its own
fallback compatible.

Signed-off-by: Michal Piekos <michal.piekos@mmpsystems.pl>
---
Changes in v2:
- Handle scenario when 0 clocks has been defined
- Fix copy&paste sentence in 3rd patch commit message
- Moved status as last property in dts node
- Make A523 its own fallback compatible
- Removed redundant maxItems/minItems properties from binding
- Link to v1: https://patch.msgid.link/20260510-sunxi-a523-gpadc-v1-0-4f6b0f4000fb@mmpsystems.pl

To: Jonathan Cameron <jic23@kernel.org>
To: David Lechner <dlechner@baylibre.com>
To: Nuno Sá <nuno.sa@analog.com>
To: Andy Shevchenko <andy@kernel.org>
To: Rob Herring <robh@kernel.org>
To: Krzysztof Kozlowski <krzk+dt@kernel.org>
To: Conor Dooley <conor+dt@kernel.org>
To: Chen-Yu Tsai <wens@kernel.org>
To: Jernej Skrabec <jernej.skrabec@gmail.com>
To: Samuel Holland <samuel@sholland.org>
To: Maksim Kiselev <bigunclemax@gmail.com>
Cc: linux-iio@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-sunxi@lists.linux.dev
Cc: linux-kernel@vger.kernel.org

---
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         | 32 +++++++++++++++++++++-
 arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi     | 11 ++++++++
 drivers/iio/adc/sun20i-gpadc-iio.c                 | 11 +++++---
 3 files changed, 49 insertions(+), 5 deletions(-)
---
base-commit: 8ab992f815d6736b5c7a6f5fd7bfe7bc106bb3dc
change-id: 20260507-sunxi-a523-gpadc-1879aa5df754

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

[PATCH v2 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         | 32 +++++++++++++++++++++-
 1 file changed, 31 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..6467800d30e2 100644
--- a/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml
+++ b/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml
@@ -14,6 +14,7 @@ properties:
     oneOf:
       - enum:
           - allwinner,sun20i-d1-gpadc
+          - allwinner,sun55i-a523-gpadc
       - items:
           - enum:
               - allwinner,sun50i-h616-gpadc
@@ -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 +46,30 @@ properties:
   resets:
     maxItems: 1
 
+allOf:
+  - if:
+      properties:
+        compatible:
+          enum:
+            - allwinner,sun55i-a523-gpadc
+    then:
+      properties:
+        clocks:
+          items:
+            - description: Bus clock
+            - description: Module clock
+        clock-names:
+          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 v2 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 | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/adc/sun20i-gpadc-iio.c b/drivers/iio/adc/sun20i-gpadc-iio.c
index 861c14da75ad..3f1f07b3a385 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 +205,11 @@ 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 or no clocks defined\n");
 
 	rst = devm_reset_control_get_exclusive(dev, NULL);
 	if (IS_ERR(rst))
@@ -243,6 +245,7 @@ static int sun20i_gpadc_probe(struct platform_device *pdev)
 
 static const struct of_device_id sun20i_gpadc_of_id[] = {
 	{ .compatible = "allwinner,sun20i-d1-gpadc" },
+	{ .compatible = "allwinner,sun55i-a523-gpadc" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, sun20i_gpadc_of_id);

-- 
2.43.0

Re: [PATCH v2 2/3] iio: adc: sun20i-gpadc: add A523 gpadc support

[Sanjay Chitroda]

On 13 May 2026 10:29:43 am IST, 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>
>---
> drivers/iio/adc/sun20i-gpadc-iio.c | 11 +++++++----
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
>diff --git a/drivers/iio/adc/sun20i-gpadc-iio.c b/drivers/iio/adc/sun20i-gpadc-iio.c
>index 861c14da75ad..3f1f07b3a385 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 +205,11 @@ 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)

Thank you Michal for the change.

Have you validated the changes ?
It looks while success ret would be 0 and it would give return error.

Thanks, Sanjay


>+		return dev_err_probe(
>+			dev, ret,
>+			"failed to enable clocks or no clocks defined\n");
> 
> 	rst = devm_reset_control_get_exclusive(dev, NULL);
> 	if (IS_ERR(rst))
>@@ -243,6 +245,7 @@ static int sun20i_gpadc_probe(struct platform_device *pdev)
> 
> static const struct of_device_id sun20i_gpadc_of_id[] = {
> 	{ .compatible = "allwinner,sun20i-d1-gpadc" },
>+	{ .compatible = "allwinner,sun55i-a523-gpadc" },
> 	{ }
> };
> MODULE_DEVICE_TABLE(of, sun20i_gpadc_of_id);
>

Re: [PATCH v2 2/3] iio: adc: sun20i-gpadc: add A523 gpadc support

[Andre Przywara]

Hi Sanjay,

thanks for having a look!

On 5/13/26 13:44, Sanjay Chitroda wrote:
> 
> 
> On 13 May 2026 10:29:43 am IST, 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>
>> ---
>> drivers/iio/adc/sun20i-gpadc-iio.c | 11 +++++++----
>> 1 file changed, 7 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/iio/adc/sun20i-gpadc-iio.c b/drivers/iio/adc/sun20i-gpadc-iio.c
>> index 861c14da75ad..3f1f07b3a385 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 +205,11 @@ 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)
> 
> Thank you Michal for the change.
> 
> Have you validated the changes ?
> It looks while success ret would be 0 and it would give return error.

But devm_clk_bulk_get_all_enabled() returns the number of clocks found 
and enabled. And since we need at least one, I think this is correct, 
and the error message below reflects that.

To me that change looks good:

Reviewed-by: Andre Przywara <andre.przywara@arm.com>

Cheers,
Andre


> 
> Thanks, Sanjay
> 
> 
>> +		return dev_err_probe(
>> +			dev, ret,
>> +			"failed to enable clocks or no clocks defined\n");
>>
>> 	rst = devm_reset_control_get_exclusive(dev, NULL);
>> 	if (IS_ERR(rst))
>> @@ -243,6 +245,7 @@ static int sun20i_gpadc_probe(struct platform_device *pdev)
>>
>> static const struct of_device_id sun20i_gpadc_of_id[] = {
>> 	{ .compatible = "allwinner,sun20i-d1-gpadc" },
>> +	{ .compatible = "allwinner,sun55i-a523-gpadc" },
>> 	{ }
>> };
>> MODULE_DEVICE_TABLE(of, sun20i_gpadc_of_id);
>>
> 

[PATCH v2 3/3] arm64: dts: allwinner: a523: add gpadc node

[Michal Piekos]

Describe GPADC block on Allwinner A523.

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 | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi b/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi
index 5afa8d92acbf..4e793aeccf89 100644
--- a/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi
+++ b/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi
@@ -340,6 +340,17 @@ ledc: led-controller@2008000 {
 			status = "disabled";
 		};
 
+		gpadc: adc@2009000 {
+			compatible = "allwinner,sun55i-a523-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>;
+			#io-channel-cells = <1>;
+			status = "disabled";
+		};
+
 		wdt: watchdog@2050000 {
 			compatible = "allwinner,sun55i-a523-wdt";
 			reg = <0x2050000 0x20>;

-- 
2.43.0