Add support for Allwinner GPADC on D1/T113s/R329/T507 SoCs

This series adds support for general purpose ADC (GPADC) on new Allwinner's SoCs, such as D1, T113s, T507 and R329. The implemented driver provides basic functionality for getting ADC channels data.

Change History:
v6:
- Fixed DT bindings regexp for channel properties
- Dropped checking the max number of channels from the drivers code (This is redundant as we raly on DT bindings check)

v5:
- Fixed DT bindings properties for child nodes

v4:
- Fixed DT bindings warnings
- Used GENMASK to clear the irq register
- Minor formatting fixes

v3:
- Added DT bindings dual license, fixed property order and example formatting
- Added explanations comments for timeout and mutex
- Dropped unnecessary regmap and used readl/writel instead
- Added error message about getting channel number
- Renamed labels and variables to make them self-explanatory

v2:
- Added lastch flag to avoid addition work for already selected channel
- Added reset assertion on module remove
- Added dynamic channel allocation and dropped iio_chan_spec arrays
- Changed IIO_CHAN_INFO_SCALE type to FRACTIONAL_LOG2
- Dropped separate compatible strings and configs for T113s and R329
- Fixed includes
- Fixed Kconfig description
- Removed duplicate probe error messages
- Used FIELD_PREP for bit setup

v1:
- Initial version

Maksim Kiselev (3):
iio: adc: Add Allwinner D1/T113s/R329/T507 SoCs GPADC
dt-bindings: iio: adc: Add Allwinner D1/T113s/R329/T507 SoCs GPADC
riscv: dts: allwinner: d1: Add GPADC node

 .../iio/adc/allwinner,sun20i-d1-gpadc.yaml    |  91 ++++++
 .../boot/dts/allwinner/sunxi-d1s-t113.dtsi    |  10 +
 drivers/iio/adc/Kconfig                       |  10 +
 drivers/iio/adc/Makefile                      |   1 +
 drivers/iio/adc/sun20i-gpadc-iio.c            | 276 ++++++++++++++++++
 5 files changed, 388 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml
 create mode 100644 drivers/iio/adc/sun20i-gpadc-iio.c

2.39.2

The General Purpose ADC (GPADC) can convert the external signal into a certain proportion of digital value, to realize the measurement of analog signal, which can be applied to power detection and key detection.

Theoretically, this ADC can support up to 16 channels. All SoCs below contain this GPADC IP. The only difference between them is the number of available channels:

T113 - 1 channel
D1 - 2 channels
R329 - 4 channels
T507 - 4 channels

---
 drivers/iio/adc/Kconfig            |  10 ++
 drivers/iio/adc/Makefile           |   1 +
 drivers/iio/adc/sun20i-gpadc-iio.c | 276 +++++++++++++++++++++++++++++
 3 files changed, 287 insertions(+)
 create mode 100644 drivers/iio/adc/sun20i-gpadc-iio.c

index eb2b09ef5d5b..deff7ae704ce 100644
@@ -1123,6 +1123,16 @@ config SUN4I_GPADC
 	  To compile this driver as a module, choose M here: the module will be
 	  called sun4i-gpadc-iio.
 
+config SUN20I_GPADC
+	tristate "Support for the Allwinner SoCs GPADC"
+	depends on ARCH_SUNXI || COMPILE_TEST
+	help
+	  Say yes here to build support for Allwinner (D1, T113, T507 and R329)
+	  SoCs GPADC. This ADC provides up to 16 channels.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called sun20i-gpadc-iio.
+
 config TI_ADC081C
 	tristate "Texas Instruments ADC081C/ADC101C/ADC121C family"
 	depends on I2C

index e07e4a3e6237..fc4ef71d5f8f 100644
@@ -95,6 +95,7 @@ obj-$(CONFIG_RZG2L_ADC) += rzg2l_adc.o
 obj-$(CONFIG_SC27XX_ADC) += sc27xx_adc.o
 obj-$(CONFIG_SPEAR_ADC) += spear_adc.o
 obj-$(CONFIG_SUN4I_GPADC) += sun4i-gpadc-iio.o
+obj-$(CONFIG_SUN20I_GPADC) += sun20i-gpadc-iio.o
 obj-$(CONFIG_STM32_ADC_CORE) += stm32-adc-core.o
 obj-$(CONFIG_STM32_ADC) += stm32-adc.o
 obj-$(CONFIG_STM32_DFSDM_CORE) += stm32-dfsdm-core.o

2.39.2

Allwinner's D1/T113s/R329/T507 SoCs have a new general purpose ADC. This ADC is the same for all of this SoCs. The only difference is the number of available channels.

---
 .../iio/adc/allwinner,sun20i-d1-gpadc.yaml    | 91 +++++++++++++++++++
 1 file changed, 91 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml

new file mode 100644
index 000000000000..23c584f5a6e6
@@ -0,0 +1,91 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/allwinner,sun20i-d1-gpadc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Allwinner D1 General Purpose ADC
+
+maintainers:
+  - Maksim Kiselev <[email protected]>
+
+properties:
+  compatible:
+    enum:
+      - allwinner,sun20i-d1-gpadc
+
+  "#io-channel-cells":
+    const: 1
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  clocks:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  reg:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+patternProperties:
+  "^channel@[0-9a-f]+$":
+    $ref: adc.yaml
+    type: object
+    description:
+      Represents the internal channels of the ADC.
+
+    properties:
+      reg:
+        items:
+          minimum: 0
+          Maksimum: 15
+
+    required:
+      - reg
+
+    unevaluatedProperties: false
+
+required:
+  - "#io-channel-cells"
+  - clocks
+  - compatible
+  - interrupts
+  - reg
+  - resets
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/sun20i-d1-ccu.h>
+    #include <dt-bindings/reset/sun20i-d1-ccu.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    gpadc: adc@2009000 {
+        compatible = "allwinner,sun20i-d1-gpadc";
+        reg = <0x2009000 0x1000>;
+        clocks = <&ccu CLK_BUS_GPADC>;
+        resets = <&ccu RST_BUS_GPADC>;
+        interrupts = <73 IRQ_TYPE_LEVEL_HIGH>;
+        #io-channel-cells = <1>;
+
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        channel@0 {
+            reg = <0>;
+        };
+
+        channel@1 {
+            reg = <1>;
+        };
+    };
+...

2.39.2

My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check' on your patch (DT_CHECKER_FLAGS is new in v5.13):

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml: patternProperties:^channel@[0-9a-f]+$:properties:reg:items: 'oneOf' conditional failed, one must be fixed:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml: patternProperties:^channel@[0-9a-f]+$:properties:reg:items: 'anyOf' conditional failed, one must be fixed:
'Maksimum' is not one of ['$ref', 'additionalItems', 'additionalProperties', 'allOf', 'anyOf', 'const', 'contains', 'default', 'dependencies', 'dependentRequired', 'dependentSchemas', 'deprecated', 'description', 'else', 'enum', 'exclusiveMaximum', 'exclusiveMinimum', 'items', 'if', 'minItems', 'minimum', 'maxItems', 'maximum', 'multipleOf', 'not', 'oneOf', 'pattern', 'patternProperties', 'properties', 'required', 'then', 'typeSize', 'unevaluatedProperties', 'uniqueItems'] 'type' was expected
from schema $id: http://devicetree.org/meta-schemas/core.yaml#
{'minimum': 0, 'Maksimum': 15} is not of type 'array'
from schema $id: http://devicetree.org/meta-schemas/core.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml: patternProperties:^channel@[0-9a-f]+$:properties:reg: 'anyOf' conditional failed, one must be fixed:
'maxItems' is a required property
hint: Only "maxItems" is required for a single entry if there are no constraints defined for the values.
'items' is not one of ['maxItems', 'description', 'deprecated']
'items' is not one of ['description', 'deprecated', 'const', 'enum', 'minimum', 'maximum', 'multipleOf', 'default', '$ref', 'oneOf']
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml: patternProperties:^channel@[0-9a-f]+$:properties:reg:items: 'oneOf' conditional failed, one must be fixed:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml: patternProperties:^channel@[0-9a-f]+$:properties:reg:items: 'anyOf' conditional failed, one must be fixed:
'maxItems' is a required property
hint: Only "maxItems" is required for a single entry if there are no constraints defined for the values.
'minimum' is not one of ['maxItems', 'description', 'deprecated']
'Maksimum' is not one of ['maxItems', 'description', 'deprecated']
Additional properties are not allowed ('Maksimum', 'minimum' were unexpected)
hint: Arrays must be described with a combination of minItems/maxItems/items
'Maksimum' is not one of ['description', 'deprecated', 'const', 'enum', 'minimum', 'maximum', 'multipleOf', 'default', '$ref', 'oneOf']
hint: cell array properties must define how many entries and what the entries are when there is more than one entry.
from schema $id: http://devicetree.org/meta-schemas/core.yaml#
{'minimum': 0, 'Maksimum': 15} is not of type 'array'
hint: "items" can be a list defining each entry or a schema applying to all items. A list has an implicit size. A schema requires minItems/maxItems to define the size.
from schema $id: http://devicetree.org/meta-schemas/core.yaml#
hint: cell array properties must define how many entries and what the entries are when there is more than one entry.
from schema $id: http://devicetree.org/meta-schemas/core.yaml#

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/[email protected]

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.

Allwinner's D1/T113s/R329/T507 SoCs have a new general purpose ADC. This ADC is the same for all of this SoCs. The only difference is the number of available channels.

---
 .../iio/adc/allwinner,sun20i-d1-gpadc.yaml    | 91 +++++++++++++++++++
 1 file changed, 91 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/allwinner,sun20i-d1-gpadc.yaml

new file mode 100644
index 000000000000..23c584f5a6e6
@@ -0,0 +1,91 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/allwinner,sun20i-d1-gpadc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Allwinner D1 General Purpose ADC
+
+maintainers:
+  - Maksim Kiselev <[email protected]>
+
+properties:
+  compatible:
+    enum:
+      - allwinner,sun20i-d1-gpadc
+
+  "#io-channel-cells":
+    const: 1
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  clocks:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  reg:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+patternProperties:
+  "^channel@[0-9a-f]+$":
+    $ref: adc.yaml
+    type: object
+    description:
+      Represents the internal channels of the ADC.
+
+    properties:
+      reg:
+        items:
+          minimum: 0
+          maximum: 15
+
+    required:
+      - reg
+
+    unevaluatedProperties: false
+
+required:
+  - "#io-channel-cells"
+  - clocks
+  - compatible
+  - interrupts
+  - reg
+  - resets
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/sun20i-d1-ccu.h>
+    #include <dt-bindings/reset/sun20i-d1-ccu.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    gpadc: adc@2009000 {
+        compatible = "allwinner,sun20i-d1-gpadc";
+        reg = <0x2009000 0x1000>;
+        clocks = <&ccu CLK_BUS_GPADC>;
+        resets = <&ccu RST_BUS_GPADC>;
+        interrupts = <73 IRQ_TYPE_LEVEL_HIGH>;
+        #io-channel-cells = <1>;
+
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        channel@0 {
+            reg = <0>;
+        };
+
+        channel@1 {
+            reg = <1>;
+        };
+    };
+...

2.39.2

Do not attach (thread) your patchsets to some other threads (unrelated or older versions). This buries them deep in the mailbox and might interfere with applying entire sets.

Don't send the same patches twice. This is v6 or was v6 or is what?

Wait for feedback and send corrected patchset next day. If you tested your patches before sending, which actually *is a requirement*, all mess could be avoided. Sending same version twice is not a solution for missing testing.

Best regards,
Krzysztof

This patch adds declaration of the general purpose ADC for D1 and T113s SoCs.

---
 arch/riscv/boot/dts/allwinner/sunxi-d1s-t113.dtsi | 10 ++++++++++
 1 file changed, 10 insertions(+)

index 922e8e0e2c09..90c79041cfba 100644
@@ -138,6 +138,16 @@ ccu: clock-controller@2001000 {
 			#reset-cells = <1>;
 		};
 
+		gpadc: adc@2009000 {
+			compatible = "allwinner,sun20i-d1-gpadc";
+			reg = <0x2009000 0x1000>;
+			clocks = <&ccu CLK_BUS_GPADC>;
+			resets = <&ccu RST_BUS_GPADC>;
+			interrupts = <SOC_PERIPHERAL_IRQ(57) IRQ_TYPE_LEVEL_HIGH>;
+			status = "disabled";
+			#io-channel-cells = <1>;
+		};
+
 		dmic: dmic@2031000 {
 			compatible = "allwinner,sun20i-d1-dmic",
 				     "allwinner,sun50i-h6-dmic";

2.39.2