* [PATCH v4 01/11] dt-bindings: iio: adc: Add AD4170
2025-06-02 11:34 [PATCH v4 00/11] iio: adc: Add support for AD4170 series of ADCs Marcelo Schmitt
@ 2025-06-02 11:36 ` Marcelo Schmitt
2025-06-02 12:23 ` Rob Herring (Arm)
2025-06-07 16:45 ` Jonathan Cameron
2025-06-02 11:36 ` [PATCH v4 02/11] iio: adc: Add basic support for AD4170 Marcelo Schmitt
` (9 subsequent siblings)
10 siblings, 2 replies; 29+ messages in thread
From: Marcelo Schmitt @ 2025-06-02 11:36 UTC (permalink / raw)
To: linux-iio, devicetree, linux-gpio, linux-kernel
Cc: jic23, lars, Michael.Hennerich, dlechner, nuno.sa, andy, robh,
krzk+dt, conor+dt, linus.walleij, brgl, marcelo.schmitt1
Add device tree documentation for AD4170 and similar sigma-delta ADCs.
The AD4170 is a 24-bit, multichannel, sigma-delta ADC.
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
---
Change log v3 -> v4
- Dropped sensor-node and most of defs.
- Updated external sensor props to have similar name and type of adi,ad4130 ones.
- Added constraints to properties related to external bridge sensor excitation.
Some explanation about the constraints to weigh scale sensor types.
The predefined ACX1, ACX1 negated, ACX2, and ACX2 negated signals are used to AC
excite external bridge circuits and are output on GPIO2, GPIO0, GPIO3, and
GPIO1, respectively. If only two pins are specified for AC excitation, only ACX1
and ACX2 (GPIO2 and GPIO3) are used. Because of that, if AC excitation is
specified/requested, then those specific GPIO pins must be used with the bridge.
Otherwise, the bridge won't get properly excited and we also cannot guarantee to
avoid short-circuit conditions since the level set to GPIOs to DC excite the
bridge depends on the GPIO number. See AD4170 datasheet Figure 113 Weigh Scale
(AC Excitation) for the reference circuit diagram.
Link: https://www.analog.com/media/en/technical-documentation/data-sheets/ad4170-4.pdf#unique_149_Connect_42_ID10354
.../bindings/iio/adc/adi,ad4170.yaml | 543 ++++++++++++++++++
MAINTAINERS | 7 +
2 files changed, 550 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ad4170.yaml
diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad4170.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad4170.yaml
new file mode 100644
index 000000000000..87b6e821fdb8
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/adi,ad4170.yaml
@@ -0,0 +1,543 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/adi,ad4170.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices AD4170 and similar Analog to Digital Converters
+
+maintainers:
+ - Marcelo Schmitt <marcelo.schmitt@analog.com>
+
+description: |
+ Analog Devices AD4170 series of Sigma-delta Analog to Digital Converters.
+ Specifications can be found at:
+ https://www.analog.com/media/en/technical-documentation/data-sheets/ad4170-4.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/ad4190-4.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/ad4195-4.pdf
+
+$ref: /schemas/spi/spi-peripheral-props.yaml#
+
+$defs:
+ reference-buffer:
+ description: |
+ Enable precharge buffer, full buffer, or skip reference buffering of
+ the positive/negative voltage reference. Because the output impedance
+ of the source driving the voltage reference inputs may be dynamic, RC
+ combinations of those inputs can cause DC gain errors if the reference
+ inputs go unbuffered into the ADC. Enable reference buffering if the
+ provided reference source has dynamic high impedance output. Note the
+ absolute voltage allowed on REFINn+ and REFINn- inputs is from
+ AVSS - 50 mV to AVDD + 50 mV when the reference buffers are disabled
+ but narrows to AVSS to AVDD when reference buffering is enabled or in
+ precharge mode. The valid options for this property are:
+ 0: Reference precharge buffer.
+ 1: Full reference buffering.
+ 2: Bypass reference buffers (buffering disabled).
+ $ref: /schemas/types.yaml#/definitions/uint32
+ enum: [0, 1, 2]
+ default: 1
+
+ excitation-pin:
+ description: |
+ Analog input to apply excitation current to while the channel
+ is active.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 20
+
+properties:
+ compatible:
+ enum:
+ - adi,ad4170
+ - adi,ad4190
+ - adi,ad4195
+
+ avss-supply:
+ description:
+ Reference voltage supply for AVSS. If provided, describes the magnitude
+ (absolute value) of the negative voltage supplied to the AVSS pin. Since
+ AVSS must be −2.625V minimum and 0V maximum, the declared supply voltage
+ must be between 0 and 2.65V. If not provided, AVSS is assumed to be at
+ system ground (0V).
+
+ avdd-supply:
+ description:
+ A supply of 4.75V to 5.25V relative to AVSS that powers the chip (AVDD).
+
+ iovdd-supply:
+ description: 1.7V to 5.25V reference supply to the serial interface (IOVDD).
+
+ refin1p-supply:
+ description: REFIN+ supply that can be used as reference for conversion.
+
+ refin1n-supply:
+ description: REFIN- supply that can be used as reference for conversion. If
+ provided, describes the magnitude (absolute value) of the negative voltage
+ supplied to the REFIN- pin.
+
+ refin2p-supply:
+ description: REFIN2+ supply that can be used as reference for conversion.
+
+ refin2n-supply:
+ description: REFIN2- supply that can be used as reference for conversion. If
+ provided, describes the magnitude (absolute value) of the negative voltage
+ supplied to the REFIN2- pin.
+
+ spi-cpol: true
+
+ spi-cpha: true
+
+ interrupts:
+ description:
+ Interrupt for signaling the completion of conversion results. The data
+ ready signal (RDY) used as interrupt is by default provided on the SDO
+ pin. Alternatively, it can be provided on the DIG_AUX1 pin in which case
+ the chip disables the RDY function on SDO. Thus, there can be only one
+ data ready interrupt enabled at a time.
+ maxItems: 1
+
+ interrupt-names:
+ description:
+ Specify which pin should be configured as Data Ready interrupt.
+ enum:
+ - sdo
+ - dig_aux1
+ maxItems: 1
+ default: sdo
+
+ clocks:
+ maxItems: 1
+ description:
+ Optional external clock source. Can specify either an external clock or
+ external crystal.
+
+ clock-names:
+ enum:
+ - ext-clk
+ - xtal
+ default: ext-clk
+
+ '#clock-cells':
+ const: 0
+
+ clock-output-names:
+ maxItems: 1
+
+ gpio-controller: true
+
+ "#gpio-cells":
+ const: 2
+ description: |
+ The first cell is for the GPIO number: 0 to 3.
+ The second cell takes standard GPIO flags.
+
+ ldac-gpios:
+ description:
+ GPIO connected to DIG_AUX2 pin to be used as LDAC toggle to control the
+ transfer of data from the DAC_INPUT_A register to the DAC.
+ maxItems: 1
+
+ '#address-cells':
+ const: 1
+
+ '#size-cells':
+ const: 0
+
+ adi,vbias-pins:
+ description: Analog inputs to apply a voltage bias of (AVDD − AVSS) / 2 to.
+ $ref: /schemas/types.yaml#/definitions/uint32-array
+ minItems: 1
+ maxItems: 9
+ items:
+ minimum: 0
+ maximum: 8
+
+allOf:
+ # Some devices don't have integrated DAC
+ - if:
+ properties:
+ compatible:
+ contains:
+ enum:
+ - adi,ad4190
+ - adi,ad4195
+ then:
+ properties:
+ ldac-gpios: false
+
+ # If an external clock is set, the internal clock cannot go out and vice versa
+ - oneOf:
+ - required: [clocks]
+ properties:
+ '#clock-cells': false
+ - required: ['#clock-cells']
+ properties:
+ clocks: false
+
+patternProperties:
+ "^channel@[0-9a-f]$":
+ $ref: /schemas/iio/adc/adc.yaml#
+ unevaluatedProperties: false
+ description:
+ Represents the external channels which are connected to the ADC.
+
+ properties:
+ reg:
+ description:
+ The channel number.
+ minimum: 0
+ maximum: 15
+
+ diff-channels:
+ description: |
+ This property is used for defining the inputs of a differential
+ voltage channel. The first value is the positive input and the second
+ value is the negative input of the channel.
+
+ Besides the analog input pins AIN0 to AIN8, there are special inputs
+ that can be selected with the following values:
+ 17: Internal temperature sensor
+ 18: (AVDD-AVSS)/5
+ 19: (IOVDD-DGND)/5
+ 20: DAC output
+ 21: ALDO
+ 22: DLDO
+ 23: AVSS
+ 24: DGND
+ 25: REFIN+
+ 26: REFIN-
+ 27: REFIN2+
+ 28: REFIN2-
+ 29: REFOUT
+ For the internal temperature sensor, use the input number for both
+ inputs (i.e. diff-channels = <17 17>).
+ items:
+ enum: [0, 1, 2, 3, 4, 5, 6, 7, 8, 17, 18, 19, 20, 21, 22, 23, 24, 25,
+ 26, 27, 28, 29]
+
+ adi,reference-select:
+ description: |
+ Select the reference source to use when converting on the
+ specific channel. Valid values are:
+ 0: REFIN+/REFIN-
+ 1: REFIN2+/REFIN2−
+ 2: REFOUT/AVSS (internal reference)
+ 3: AVDD/AVSS
+ If not specified, REFOUT/AVSS is used.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ enum: [0, 1, 2, 3]
+ default: 1
+
+ adi,positive-reference-buffer:
+ $ref: '#/$defs/reference-buffer'
+
+ adi,negative-reference-buffer:
+ $ref: '#/$defs/reference-buffer'
+
+ adi,sensor-type:
+ description:
+ The AD4170 and similar designs have features to aid interfacing with
+ load cell weigh scale, RTD, and thermocouple sensors. Each of those
+ sensor types requires either distinct wiring configuration or
+ external circuitry for proper sensor operation and can use different
+ ADC chip functionality on their setups. A key characteristic of those
+ external sensors is that they must be excited either by voltage supply
+ or by ADC chip excitation signals. The sensor can then be read through
+ a pair of analog inputs. This property specifies which particular
+ sensor type is connected to the ADC so it can be properly setup and
+ handled. Omit this property for conventional (not weigh scale, RTD, or
+ thermocouple) ADC channel setups.
+ $ref: /schemas/types.yaml#/definitions/string
+ enum: [ weighscale, rtd, thermocouple ]
+
+ adi,excitation-pin-0:
+ $ref: '#/$defs/excitation-pin'
+
+ adi,excitation-pin-1:
+ $ref: '#/$defs/excitation-pin'
+
+ adi,excitation-pin-2:
+ $ref: '#/$defs/excitation-pin'
+
+ adi,excitation-pin-3:
+ $ref: '#/$defs/excitation-pin'
+
+ adi,excitation-current-0-microamp:
+ description:
+ Excitation current in microamperes to be applied to pin specified in
+ adi,excitation-pin-0 while this channel is active.
+ enum: [0, 10, 50, 100, 250, 500, 1000, 1500]
+ default: 0
+
+ adi,excitation-current-1-microamp:
+ description:
+ Excitation current in microamperes to be applied to pin specified in
+ adi,excitation-pin-1 while this channel is active.
+ enum: [0, 10, 50, 100, 250, 500, 1000, 1500]
+ default: 0
+
+ adi,excitation-current-2-microamp:
+ description:
+ Excitation current in microamperes to be applied to pin specified in
+ adi,excitation-pin-2 while this channel is active.
+ enum: [0, 10, 50, 100, 250, 500, 1000, 1500]
+ default: 0
+
+ adi,excitation-current-3-microamp:
+ description:
+ Excitation current in microamperes to be applied to pin specified in
+ adi,excitation-pin-3 while this channel is active.
+ enum: [0, 10, 50, 100, 250, 500, 1000, 1500]
+ default: 0
+
+ adi,excitation-ac:
+ type: boolean
+ description:
+ Whether the external sensor has to be AC or DC excited. When omitted,
+ it is DC excited.
+
+ allOf:
+ - oneOf:
+ - required: [single-channel, common-mode-channel]
+ properties:
+ diff-channels: false
+ - required: [diff-channels]
+ properties:
+ single-channel: false
+ common-mode-channel: false
+ # Usual ADC channels don't need external circuitry excitation.
+ - if:
+ not:
+ required:
+ - adi,sensor-type
+ then:
+ properties:
+ adi,excitation-pin-0: false
+ adi,excitation-pin-1: false
+ adi,excitation-pin-2: false
+ adi,excitation-pin-3: false
+ adi,excitation-current-0-microamp: false
+ adi,excitation-current-1-microamp: false
+ adi,excitation-current-2-microamp: false
+ adi,excitation-current-3-microamp: false
+ adi,excitation-ac: false
+ # Weigh scale bridge AC excited with one pair of predefined signals.
+ - if:
+ allOf:
+ - properties:
+ adi,sensor-type:
+ contains:
+ const: weighscale
+ - required:
+ - adi,excitation-ac
+ - adi,excitation-pin-2
+ - adi,excitation-pin-3
+ - not:
+ required:
+ - adi,excitation-current-2-microamp
+ - adi,excitation-current-3-microamp
+ then:
+ properties:
+ adi,excitation-pin-2:
+ const: 19
+ adi,excitation-pin-3:
+ const: 20
+ # Weigh scale bridge AC excited with two pairs of predefined signals.
+ - if:
+ allOf:
+ - properties:
+ adi,sensor-type:
+ contains:
+ const: weighscale
+ - required:
+ - adi,excitation-ac
+ - adi,excitation-pin-0
+ - adi,excitation-pin-1
+ - adi,excitation-pin-2
+ - adi,excitation-pin-3
+ - not:
+ required:
+ - adi,excitation-current-0-microamp
+ - adi,excitation-current-1-microamp
+ - adi,excitation-current-2-microamp
+ - adi,excitation-current-3-microamp
+ then:
+ properties:
+ adi,excitation-pin-0:
+ const: 17
+ adi,excitation-pin-1:
+ const: 18
+ adi,excitation-pin-2:
+ const: 19
+ adi,excitation-pin-3:
+ const: 20
+
+required:
+ - compatible
+ - reg
+ - avdd-supply
+ - iovdd-supply
+ - spi-cpol
+ - spi-cpha
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/irq.h>
+ spi {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ adc@0 {
+ compatible = "adi,ad4170";
+ reg = <0>;
+ spi-max-frequency = <20000000>;
+ spi-cpol;
+ spi-cpha;
+ avdd-supply = <&avdd>;
+ iovdd-supply = <&iovdd>;
+ clocks = <&clk>;
+ clock-names = "xtal";
+ interrupt-parent = <&gpio_in>;
+ interrupts = <0 IRQ_TYPE_EDGE_FALLING>;
+ adi,vbias-pins = <7>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ // Sample AIN0 with respect to DGND throughout AVDD/DGND input range
+ // Pseudo-differential unipolar
+ channel@0 {
+ reg = <0>;
+ single-channel = <0>;
+ common-mode-channel = <24>;
+ adi,reference-select = <3>;
+ };
+ // Weigh scale sensor
+ channel@1 {
+ reg = <1>;
+ bipolar;
+ diff-channels = <1 2>;
+ adi,reference-select = <0>;
+ adi,positive-reference-buffer = <0>;
+ adi,negative-reference-buffer = <0>;
+ adi,sensor-type = "weighscale";
+ adi,excitation-pin-2 = <19>;
+ adi,excitation-pin-3 = <20>;
+ adi,excitation-ac;
+ };
+ // RTD sensor
+ channel@2 {
+ reg = <2>;
+ bipolar;
+ diff-channels = <3 4>;
+ adi,reference-select = <0>;
+ adi,sensor-type = "rtd";
+ adi,excitation-pin-0 = <5>;
+ adi,excitation-pin-1 = <6>;
+ adi,excitation-current-0-microamp = <500>;
+ adi,excitation-current-1-microamp = <500>;
+ adi,excitation-ac;
+ };
+ // Thermocouple sensor
+ channel@3 {
+ reg = <3>;
+ bipolar;
+ diff-channels = <7 8>;
+ adi,reference-select = <0>;
+ adi,sensor-type = "thermocouple";
+ adi,excitation-pin-0 = <18>;
+ adi,excitation-current-0-microamp = <500>;
+ };
+ };
+ };
+ - |
+ #include <dt-bindings/interrupt-controller/irq.h>
+ spi {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ adc@0 {
+ compatible = "adi,ad4170";
+ reg = <0>;
+ spi-max-frequency = <20000000>;
+ spi-cpol;
+ spi-cpha;
+ avdd-supply = <&avdd>;
+ iovdd-supply = <&iovdd>;
+ #clock-cells = <0>;
+ clock-output-names = "ad4170-clk16mhz";
+ interrupt-parent = <&gpio_in>;
+ interrupts = <0 IRQ_TYPE_EDGE_FALLING>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ // Sample AIN0 with respect to AIN1 throughout AVDD/AVSS input range
+ // Differential bipolar. If AVSS < 0V, differential true bipolar
+ channel@0 {
+ reg = <0>;
+ bipolar;
+ diff-channels = <0 1>;
+ adi,reference-select = <3>;
+ };
+ // Sample AIN2 with respect to DGND throughout AVDD/DGND input range
+ // Pseudo-differential unipolar
+ channel@1 {
+ reg = <1>;
+ single-channel = <2>;
+ common-mode-channel = <24>;
+ adi,reference-select = <3>;
+ };
+ // Sample AIN3 with respect to 2.5V throughout AVDD/AVSS input range
+ // Pseudo-differential bipolar
+ channel@2 {
+ reg = <2>;
+ bipolar;
+ single-channel = <3>;
+ common-mode-channel = <29>;
+ adi,reference-select = <3>;
+ };
+ // Sample AIN4 with respect to DGND throughout AVDD/AVSS input range
+ // Pseudo-differential bipolar
+ channel@3 {
+ reg = <3>;
+ bipolar;
+ single-channel = <4>;
+ common-mode-channel = <24>;
+ adi,reference-select = <3>;
+ };
+ // Sample AIN5 with respect to 2.5V throughout AVDD/AVSS input range
+ // Pseudo-differential unipolar (AD4170 datasheet page 46 example)
+ channel@4 {
+ reg = <4>;
+ single-channel = <5>;
+ common-mode-channel = <29>;
+ adi,reference-select = <3>;
+ };
+ // Sample AIN6 with respect to 2.5V throughout REFIN+/REFIN- input range
+ // Pseudo-differential bipolar
+ channel@5 {
+ reg = <5>;
+ bipolar;
+ single-channel = <6>;
+ common-mode-channel = <29>;
+ adi,reference-select = <0>;
+ };
+ // Weigh scale sensor
+ channel@6 {
+ reg = <6>;
+ bipolar;
+ diff-channels = <7 8>;
+ adi,reference-select = <0>;
+ adi,sensor-type = "weighscale";
+ adi,excitation-pin-0 = <17>;
+ adi,excitation-pin-1 = <18>;
+ adi,excitation-pin-2 = <19>;
+ adi,excitation-pin-3 = <20>;
+ adi,excitation-ac;
+ };
+ };
+ };
+...
+
diff --git a/MAINTAINERS b/MAINTAINERS
index 5102c25b210b..aa1e249a7b5a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1354,6 +1354,13 @@ F: Documentation/ABI/testing/sysfs-bus-iio-adc-ad4130
F: Documentation/devicetree/bindings/iio/adc/adi,ad4130.yaml
F: drivers/iio/adc/ad4130.c
+ANALOG DEVICES INC AD4170 DRIVER
+M: Marcelo Schmitt <marcelo.schmitt@analog.com>
+L: linux-iio@vger.kernel.org
+S: Supported
+W: https://ez.analog.com/linux-software-drivers
+F: Documentation/devicetree/bindings/iio/adc/adi,ad4170.yaml
+
ANALOG DEVICES INC AD4695 DRIVER
M: Michael Hennerich <michael.hennerich@analog.com>
M: Nuno Sá <nuno.sa@analog.com>
--
2.47.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* Re: [PATCH v4 01/11] dt-bindings: iio: adc: Add AD4170
2025-06-02 11:36 ` [PATCH v4 01/11] dt-bindings: iio: adc: Add AD4170 Marcelo Schmitt
@ 2025-06-02 12:23 ` Rob Herring (Arm)
2025-06-02 20:52 ` Marcelo Schmitt
2025-06-07 16:45 ` Jonathan Cameron
1 sibling, 1 reply; 29+ messages in thread
From: Rob Herring (Arm) @ 2025-06-02 12:23 UTC (permalink / raw)
To: Marcelo Schmitt
Cc: nuno.sa, andy, linus.walleij, devicetree, linux-kernel,
Michael.Hennerich, conor+dt, linux-iio, brgl, dlechner, lars,
marcelo.schmitt1, jic23, krzk+dt, linux-gpio
On Mon, 02 Jun 2025 08:36:24 -0300, Marcelo Schmitt wrote:
> Add device tree documentation for AD4170 and similar sigma-delta ADCs.
> The AD4170 is a 24-bit, multichannel, sigma-delta ADC.
>
> Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
> ---
> Change log v3 -> v4
> - Dropped sensor-node and most of defs.
> - Updated external sensor props to have similar name and type of adi,ad4130 ones.
> - Added constraints to properties related to external bridge sensor excitation.
>
> Some explanation about the constraints to weigh scale sensor types.
>
> The predefined ACX1, ACX1 negated, ACX2, and ACX2 negated signals are used to AC
> excite external bridge circuits and are output on GPIO2, GPIO0, GPIO3, and
> GPIO1, respectively. If only two pins are specified for AC excitation, only ACX1
> and ACX2 (GPIO2 and GPIO3) are used. Because of that, if AC excitation is
> specified/requested, then those specific GPIO pins must be used with the bridge.
> Otherwise, the bridge won't get properly excited and we also cannot guarantee to
> avoid short-circuit conditions since the level set to GPIOs to DC excite the
> bridge depends on the GPIO number. See AD4170 datasheet Figure 113 Weigh Scale
> (AC Excitation) for the reference circuit diagram.
> Link: https://www.analog.com/media/en/technical-documentation/data-sheets/ad4170-4.pdf#unique_149_Connect_42_ID10354
>
> .../bindings/iio/adc/adi,ad4170.yaml | 543 ++++++++++++++++++
> MAINTAINERS | 7 +
> 2 files changed, 550 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ad4170.yaml
>
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/adi,ad4170.yaml: properties:interrupt-names: 'enum' should not be valid under {'enum': ['const', 'enum', 'exclusiveMaximum', 'exclusiveMinimum', 'minimum', 'maximum', 'multipleOf', 'pattern']}
hint: Scalar and array keywords cannot be mixed
from schema $id: http://devicetree.org/meta-schemas/keywords.yaml#
doc reference errors (make refcheckdocs):
See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/187e038cb9e7dbe3991149885cb0a4b30376660c.1748829860.git.marcelo.schmitt@analog.com
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.
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [PATCH v4 01/11] dt-bindings: iio: adc: Add AD4170
2025-06-02 12:23 ` Rob Herring (Arm)
@ 2025-06-02 20:52 ` Marcelo Schmitt
2025-06-07 16:33 ` Jonathan Cameron
0 siblings, 1 reply; 29+ messages in thread
From: Marcelo Schmitt @ 2025-06-02 20:52 UTC (permalink / raw)
To: Rob Herring (Arm)
Cc: Marcelo Schmitt, nuno.sa, andy, linus.walleij, devicetree,
linux-kernel, Michael.Hennerich, conor+dt, linux-iio, brgl,
dlechner, lars, jic23, krzk+dt, linux-gpio
On 06/02, Rob Herring (Arm) wrote:
>
> On Mon, 02 Jun 2025 08:36:24 -0300, Marcelo Schmitt wrote:
> > Add device tree documentation for AD4170 and similar sigma-delta ADCs.
> > The AD4170 is a 24-bit, multichannel, sigma-delta ADC.
> >
> > Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
>
...
> 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/adi,ad4170.yaml: properties:interrupt-names: 'enum' should not be valid under {'enum': ['const', 'enum', 'exclusiveMaximum', 'exclusiveMinimum', 'minimum', 'maximum', 'multipleOf', 'pattern']}
> hint: Scalar and array keywords cannot be mixed
> from schema $id: http://devicetree.org/meta-schemas/keywords.yaml#
Removing maxItems from under interrupt-names seems to solve the issue.
Thanks
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [PATCH v4 01/11] dt-bindings: iio: adc: Add AD4170
2025-06-02 20:52 ` Marcelo Schmitt
@ 2025-06-07 16:33 ` Jonathan Cameron
0 siblings, 0 replies; 29+ messages in thread
From: Jonathan Cameron @ 2025-06-07 16:33 UTC (permalink / raw)
To: Marcelo Schmitt
Cc: Rob Herring (Arm), Marcelo Schmitt, nuno.sa, andy, linus.walleij,
devicetree, linux-kernel, Michael.Hennerich, conor+dt, linux-iio,
brgl, dlechner, lars, krzk+dt, linux-gpio
On Mon, 2 Jun 2025 17:52:31 -0300
Marcelo Schmitt <marcelo.schmitt1@gmail.com> wrote:
> On 06/02, Rob Herring (Arm) wrote:
> >
> > On Mon, 02 Jun 2025 08:36:24 -0300, Marcelo Schmitt wrote:
> > > Add device tree documentation for AD4170 and similar sigma-delta ADCs.
> > > The AD4170 is a 24-bit, multichannel, sigma-delta ADC.
> > >
> > > Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
> >
> ...
> > 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/adi,ad4170.yaml: properties:interrupt-names: 'enum' should not be valid under {'enum': ['const', 'enum', 'exclusiveMaximum', 'exclusiveMinimum', 'minimum', 'maximum', 'multipleOf', 'pattern']}
> > hint: Scalar and array keywords cannot be mixed
> > from schema $id: http://devicetree.org/meta-schemas/keywords.yaml#
>
> Removing maxItems from under interrupt-names seems to solve the issue.
As per feedback on v3. I don't think we should be limiting the max
of interrupt-names anyway. We should allow two interrupts if they
are both wired - it's a driver choice on which one to use.
>
> Thanks
>
^ permalink raw reply [flat|nested] 29+ messages in thread
* Re: [PATCH v4 01/11] dt-bindings: iio: adc: Add AD4170
2025-06-02 11:36 ` [PATCH v4 01/11] dt-bindings: iio: adc: Add AD4170 Marcelo Schmitt
2025-06-02 12:23 ` Rob Herring (Arm)
@ 2025-06-07 16:45 ` Jonathan Cameron
2025-06-09 15:28 ` Marcelo Schmitt
1 sibling, 1 reply; 29+ messages in thread
From: Jonathan Cameron @ 2025-06-07 16:45 UTC (permalink / raw)
To: Marcelo Schmitt
Cc: linux-iio, devicetree, linux-gpio, linux-kernel, lars,
Michael.Hennerich, dlechner, nuno.sa, andy, robh, krzk+dt,
conor+dt, linus.walleij, brgl, marcelo.schmitt1
On Mon, 2 Jun 2025 08:36:24 -0300
Marcelo Schmitt <marcelo.schmitt@analog.com> wrote:
> Add device tree documentation for AD4170 and similar sigma-delta ADCs.
> The AD4170 is a 24-bit, multichannel, sigma-delta ADC.
>
> Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
> ---
> Change log v3 -> v4
> - Dropped sensor-node and most of defs.
> - Updated external sensor props to have similar name and type of adi,ad4130 ones.
> - Added constraints to properties related to external bridge sensor excitation.
>
> Some explanation about the constraints to weigh scale sensor types.
>
> The predefined ACX1, ACX1 negated, ACX2, and ACX2 negated signals are used to AC
> excite external bridge circuits and are output on GPIO2, GPIO0, GPIO3, and
> GPIO1, respectively. If only two pins are specified for AC excitation, only ACX1
> and ACX2 (GPIO2 and GPIO3) are used. Because of that, if AC excitation is
> specified/requested, then those specific GPIO pins must be used with the bridge.
> Otherwise, the bridge won't get properly excited and we also cannot guarantee to
> avoid short-circuit conditions since the level set to GPIOs to DC excite the
> bridge depends on the GPIO number. See AD4170 datasheet Figure 113 Weigh Scale
> (AC Excitation) for the reference circuit diagram.
> Link: https://www.analog.com/media/en/technical-documentation/data-sheets/ad4170-4.pdf#unique_149_Connect_42_ID10354
>
> .../bindings/iio/adc/adi,ad4170.yaml | 543 ++++++++++++++++++
> MAINTAINERS | 7 +
> 2 files changed, 550 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ad4170.yaml
>
> diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad4170.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad4170.yaml
> new file mode 100644
> index 000000000000..87b6e821fdb8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad4170.yaml
> @@ -0,0 +1,543 @@
> +
> +$defs:
> + reference-buffer:
> + description: |
> + Enable precharge buffer, full buffer, or skip reference buffering of
> + the positive/negative voltage reference. Because the output impedance
> + of the source driving the voltage reference inputs may be dynamic, RC
RC?
> + combinations of those inputs can cause DC gain errors if the reference
> + inputs go unbuffered into the ADC. Enable reference buffering if the
> + provided reference source has dynamic high impedance output. Note the
> + absolute voltage allowed on REFINn+ and REFINn- inputs is from
> + AVSS - 50 mV to AVDD + 50 mV when the reference buffers are disabled
> + but narrows to AVSS to AVDD when reference buffering is enabled or in
> + precharge mode. The valid options for this property are:
> + 0: Reference precharge buffer.
> + 1: Full reference buffering.
> + 2: Bypass reference buffers (buffering disabled).
> + $ref: /schemas/types.yaml#/definitions/uint32
> + enum: [0, 1, 2]
> + default: 1
> +
> + interrupts:
> + description:
> + Interrupt for signaling the completion of conversion results. The data
> + ready signal (RDY) used as interrupt is by default provided on the SDO
> + pin. Alternatively, it can be provided on the DIG_AUX1 pin in which case
> + the chip disables the RDY function on SDO. Thus, there can be only one
> + data ready interrupt enabled at a time.
> + maxItems: 1
> +
> + interrupt-names:
> + description:
> + Specify which pin should be configured as Data Ready interrupt.
> + enum:
> + - sdo
> + - dig_aux1
> + maxItems: 1
> + default: sdo
I think I'd prefer to see it always provided as there is no strong
reason to prefer one as the default.
>
> + adi,excitation-pin-0:
> + $ref: '#/$defs/excitation-pin'
> +
> + adi,excitation-pin-1:
> + $ref: '#/$defs/excitation-pin'
> +
> + adi,excitation-pin-2:
> + $ref: '#/$defs/excitation-pin'
> +
> + adi,excitation-pin-3:
> + $ref: '#/$defs/excitation-pin'
> +
> + adi,excitation-current-0-microamp:
> + description:
> + Excitation current in microamperes to be applied to pin specified in
> + adi,excitation-pin-0 while this channel is active.
> + enum: [0, 10, 50, 100, 250, 500, 1000, 1500]
What motivated mix of using $ref and here where there is a lot of repetition?
I don't mind which approach is used, but a mix seems the worst option.
> + default: 0
> +
> + adi,excitation-current-1-microamp:
> + description:
> + Excitation current in microamperes to be applied to pin specified in
> + adi,excitation-pin-1 while this channel is active.
> + enum: [0, 10, 50, 100, 250, 500, 1000, 1500]
> + default: 0
> +
> + adi,excitation-current-2-microamp:
> + description:
> + Excitation current in microamperes to be applied to pin specified in
> + adi,excitation-pin-2 while this channel is active.
> + enum: [0, 10, 50, 100, 250, 500, 1000, 1500]
> + default: 0
> +
> + adi,excitation-current-3-microamp:
> + description:
> + Excitation current in microamperes to be applied to pin specified in
> + adi,excitation-pin-3 while this channel is active.
> + enum: [0, 10, 50, 100, 250, 500, 1000, 1500]
> + default: 0
> +
> + adi,excitation-ac:
> + type: boolean
> + description:
> + Whether the external sensor has to be AC or DC excited. When omitted,
> + it is DC excited.
> +required:
> + - compatible
> + - reg
> + - avdd-supply
> + - iovdd-supply
> + - spi-cpol
> + - spi-cpha
> +
> +unevaluatedProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/interrupt-controller/irq.h>
> + spi {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + adc@0 {
> + compatible = "adi,ad4170";
> + reg = <0>;
> + spi-max-frequency = <20000000>;
> + spi-cpol;
> + spi-cpha;
> + avdd-supply = <&avdd>;
> + iovdd-supply = <&iovdd>;
> + clocks = <&clk>;
> + clock-names = "xtal";
> + interrupt-parent = <&gpio_in>;
In examples I don't think we tend to specify interrupt-parent.
That's covered fine by the interrupt bindings.
As above, I'd prefer to always see interrupt-names as well so
we have it really visible which one this is.
> + interrupts = <0 IRQ_TYPE_EDGE_FALLING>;
> + adi,vbias-pins = <7>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> + };
> + };
> + - |
> + #include <dt-bindings/interrupt-controller/irq.h>
> + spi {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + adc@0 {
> + compatible = "adi,ad4170";
> + reg = <0>;
> + spi-max-frequency = <20000000>;
> + spi-cpol;
> + spi-cpha;
> + avdd-supply = <&avdd>;
> + iovdd-supply = <&iovdd>;
> + #clock-cells = <0>;
> + clock-output-names = "ad4170-clk16mhz";
> + interrupt-parent = <&gpio_in>;
> + interrupts = <0 IRQ_TYPE_EDGE_FALLING>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + // Sample AIN0 with respect to AIN1 throughout AVDD/AVSS input range
> + // Differential bipolar. If AVSS < 0V, differential true bipolar
> + channel@0 {
> + reg = <0>;
> + bipolar;
> + diff-channels = <0 1>;
> + adi,reference-select = <3>;
> + };
> + // Sample AIN2 with respect to DGND throughout AVDD/DGND input range
> + // Pseudo-differential unipolar
> + channel@1 {
> + reg = <1>;
> + single-channel = <2>;
> + common-mode-channel = <24>;
> + adi,reference-select = <3>;
> + };
> + // Sample AIN3 with respect to 2.5V throughout AVDD/AVSS input range
> + // Pseudo-differential bipolar
> + channel@2 {
> + reg = <2>;
> + bipolar;
> + single-channel = <3>;
> + common-mode-channel = <29>;
> + adi,reference-select = <3>;
> + };
> + // Sample AIN4 with respect to DGND throughout AVDD/AVSS input range
> + // Pseudo-differential bipolar
> + channel@3 {
> + reg = <3>;
> + bipolar;
> + single-channel = <4>;
> + common-mode-channel = <24>;
> + adi,reference-select = <3>;
> + };
> + // Sample AIN5 with respect to 2.5V throughout AVDD/AVSS input range
> + // Pseudo-differential unipolar (AD4170 datasheet page 46 example)
> + channel@4 {
> + reg = <4>;
> + single-channel = <5>;
> + common-mode-channel = <29>;
> + adi,reference-select = <3>;
> + };
> + // Sample AIN6 with respect to 2.5V throughout REFIN+/REFIN- input range
> + // Pseudo-differential bipolar
> + channel@5 {
> + reg = <5>;
> + bipolar;
> + single-channel = <6>;
> + common-mode-channel = <29>;
> + adi,reference-select = <0>;
> + };
> + // Weigh scale sensor
> + channel@6 {
> + reg = <6>;
> + bipolar;
> + diff-channels = <7 8>;
> + adi,reference-select = <0>;
> + adi,sensor-type = "weighscale";
> + adi,excitation-pin-0 = <17>;
> + adi,excitation-pin-1 = <18>;
> + adi,excitation-pin-2 = <19>;
> + adi,excitation-pin-3 = <20>;
> + adi,excitation-ac;
> + };
> + };
> + };
> +...
> +
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [PATCH v4 01/11] dt-bindings: iio: adc: Add AD4170
2025-06-07 16:45 ` Jonathan Cameron
@ 2025-06-09 15:28 ` Marcelo Schmitt
2025-06-09 15:44 ` Jonathan Cameron
0 siblings, 1 reply; 29+ messages in thread
From: Marcelo Schmitt @ 2025-06-09 15:28 UTC (permalink / raw)
To: Jonathan Cameron
Cc: Marcelo Schmitt, linux-iio, devicetree, linux-gpio, linux-kernel,
lars, Michael.Hennerich, dlechner, nuno.sa, andy, robh, krzk+dt,
conor+dt, linus.walleij, brgl
On 06/07, Jonathan Cameron wrote:
> On Mon, 2 Jun 2025 08:36:24 -0300
> Marcelo Schmitt <marcelo.schmitt@analog.com> wrote:
>
> > Add device tree documentation for AD4170 and similar sigma-delta ADCs.
> > The AD4170 is a 24-bit, multichannel, sigma-delta ADC.
> >
...
> > +
> > +$defs:
> > + reference-buffer:
> > + description: |
> > + Enable precharge buffer, full buffer, or skip reference buffering of
> > + the positive/negative voltage reference. Because the output impedance
> > + of the source driving the voltage reference inputs may be dynamic, RC
>
> RC?
Stands for the combination of resistive and capacitive elements in the path
between the reference supply output and AD4170 REFINn± inputs.
Datasheet Figure 76 shows an example with only capacitive elements, but it could
have resistive elements too.
https://www.analog.com/media/en/technical-documentation/data-sheets/ad4170-4.pdf#unique_75_Connect_42_ID8013
I will rephrase to make that clearer. This is probably too long and detailed
description for a dt property. I can't figure out how to put that in a more
concise and meaningful way, though.
>
> > + combinations of those inputs can cause DC gain errors if the reference
> > + inputs go unbuffered into the ADC. Enable reference buffering if the
> > + provided reference source has dynamic high impedance output. Note the
> > + absolute voltage allowed on REFINn+ and REFINn- inputs is from
> > + AVSS - 50 mV to AVDD + 50 mV when the reference buffers are disabled
> > + but narrows to AVSS to AVDD when reference buffering is enabled or in
> > + precharge mode. The valid options for this property are:
> > + 0: Reference precharge buffer.
> > + 1: Full reference buffering.
> > + 2: Bypass reference buffers (buffering disabled).
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + enum: [0, 1, 2]
> > + default: 1
>
...
> > +
> > + adi,excitation-current-0-microamp:
> > + description:
> > + Excitation current in microamperes to be applied to pin specified in
> > + adi,excitation-pin-0 while this channel is active.
> > + enum: [0, 10, 50, 100, 250, 500, 1000, 1500]
>
> What motivated mix of using $ref and here where there is a lot of repetition?
> I don't mind which approach is used, but a mix seems the worst option.
>
Because
$defs:
...
adi,excitation-current-n-microamp:
description:
Excitation current in microamperes to be applied to pin specified in
adi,excitation-pin-0 while this channel is active.
enum: [0, 10, 50, 100, 250, 500, 1000, 1500]
default: 0
patternProperties:
...
adi,excitation-current-0-microamp:
$ref: '#/$defs/adi,excitation-current-n-microamp'
triggers dt_binding_check warn:
patternProperties:^channel@[0-9a-f]$:properties:adi,excitation-current-0-microamp: '$ref' should not be valid under {'const': '$ref'}
hint: Standard unit suffix properties don't need a type $ref
Thanks,
Marcelo
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [PATCH v4 01/11] dt-bindings: iio: adc: Add AD4170
2025-06-09 15:28 ` Marcelo Schmitt
@ 2025-06-09 15:44 ` Jonathan Cameron
0 siblings, 0 replies; 29+ messages in thread
From: Jonathan Cameron @ 2025-06-09 15:44 UTC (permalink / raw)
To: Marcelo Schmitt
Cc: Jonathan Cameron, Marcelo Schmitt, linux-iio, devicetree,
linux-gpio, linux-kernel, lars, Michael.Hennerich, dlechner,
nuno.sa, andy, robh, krzk+dt, conor+dt, linus.walleij, brgl
On Mon, 9 Jun 2025 12:28:57 -0300
Marcelo Schmitt <marcelo.schmitt1@gmail.com> wrote:
> On 06/07, Jonathan Cameron wrote:
> > On Mon, 2 Jun 2025 08:36:24 -0300
> > Marcelo Schmitt <marcelo.schmitt@analog.com> wrote:
> >
> > > Add device tree documentation for AD4170 and similar sigma-delta ADCs.
> > > The AD4170 is a 24-bit, multichannel, sigma-delta ADC.
> > >
> ...
> > > +
> > > +$defs:
> > > + reference-buffer:
> > > + description: |
> > > + Enable precharge buffer, full buffer, or skip reference buffering of
> > > + the positive/negative voltage reference. Because the output impedance
> > > + of the source driving the voltage reference inputs may be dynamic, RC
> >
> > RC?
>
> Stands for the combination of resistive and capacitive elements in the path
> between the reference supply output and AD4170 REFINn± inputs.
Ah. My head wasn't in the right space at all. RC is common enough term but
I'd still spell it out here as DC is very near as is ADC and the C is different
in all 3 cases :)
resistance/capacitance (RC)
or something along those lines should do the job.
>
> Datasheet Figure 76 shows an example with only capacitive elements, but it could
> have resistive elements too.
> https://www.analog.com/media/en/technical-documentation/data-sheets/ad4170-4.pdf#unique_75_Connect_42_ID8013
>
> I will rephrase to make that clearer. This is probably too long and detailed
> description for a dt property. I can't figure out how to put that in a more
> concise and meaningful way, though.
>
> >
> > > + combinations of those inputs can cause DC gain errors if the reference
> > > + inputs go unbuffered into the ADC. Enable reference buffering if the
> > > + provided reference source has dynamic high impedance output. Note the
> > > + absolute voltage allowed on REFINn+ and REFINn- inputs is from
> > > + AVSS - 50 mV to AVDD + 50 mV when the reference buffers are disabled
> > > + but narrows to AVSS to AVDD when reference buffering is enabled or in
> > > + precharge mode. The valid options for this property are:
> > > + 0: Reference precharge buffer.
> > > + 1: Full reference buffering.
> > > + 2: Bypass reference buffers (buffering disabled).
> > > + $ref: /schemas/types.yaml#/definitions/uint32
> > > + enum: [0, 1, 2]
> > > + default: 1
> >
> ...
> > > +
> > > + adi,excitation-current-0-microamp:
> > > + description:
> > > + Excitation current in microamperes to be applied to pin specified in
> > > + adi,excitation-pin-0 while this channel is active.
> > > + enum: [0, 10, 50, 100, 250, 500, 1000, 1500]
> >
> > What motivated mix of using $ref and here where there is a lot of repetition?
> > I don't mind which approach is used, but a mix seems the worst option.
> >
>
> Because
> $defs:
> ...
> adi,excitation-current-n-microamp:
> description:
> Excitation current in microamperes to be applied to pin specified in
> adi,excitation-pin-0 while this channel is active.
> enum: [0, 10, 50, 100, 250, 500, 1000, 1500]
> default: 0
>
> patternProperties:
> ...
> adi,excitation-current-0-microamp:
> $ref: '#/$defs/adi,excitation-current-n-microamp'
>
>
> triggers dt_binding_check warn:
> patternProperties:^channel@[0-9a-f]$:properties:adi,excitation-current-0-microamp: '$ref' should not be valid under {'const': '$ref'}
> hint: Standard unit suffix properties don't need a type $ref
Fair enough!
J
>
>
> Thanks,
> Marcelo
>
^ permalink raw reply [flat|nested] 29+ messages in thread
* [PATCH v4 02/11] iio: adc: Add basic support for AD4170
2025-06-02 11:34 [PATCH v4 00/11] iio: adc: Add support for AD4170 series of ADCs Marcelo Schmitt
2025-06-02 11:36 ` [PATCH v4 01/11] dt-bindings: iio: adc: Add AD4170 Marcelo Schmitt
@ 2025-06-02 11:36 ` Marcelo Schmitt
2025-06-02 14:55 ` Andy Shevchenko
2025-06-03 14:00 ` kernel test robot
2025-06-02 11:37 ` [PATCH v4 03/11] iio: adc: ad4170: Add support for calibration gain Marcelo Schmitt
` (8 subsequent siblings)
10 siblings, 2 replies; 29+ messages in thread
From: Marcelo Schmitt @ 2025-06-02 11:36 UTC (permalink / raw)
To: linux-iio, devicetree, linux-gpio, linux-kernel
Cc: Ana-Maria Cusco, jic23, lars, Michael.Hennerich, dlechner,
nuno.sa, andy, robh, krzk+dt, conor+dt, linus.walleij, brgl,
marcelo.schmitt1
From: Ana-Maria Cusco <ana-maria.cusco@analog.com>
The AD4170 is a multichannel, low noise, 24-bit precision sigma-delta
analog to digital converter. The AD4170 design offers a flexible data
acquisition solution with crosspoint multiplexed analog inputs,
configurable ADC voltage reference inputs, ultra-low noise integrated PGA,
digital filtering, wide range of configurable output data rates, internal
oscillator and temperature sensor, four GPIOs, and integrated features for
interfacing with load cell weigh scales, RTD, and thermocouple sensors.
Add basic support for the AD4170 ADC with the following features:
- Single-shot read.
- Analog front end PGA configuration.
- Differential and pseudo-differential input configuration.
Signed-off-by: Ana-Maria Cusco <ana-maria.cusco@analog.com>
Co-developed-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
---
Change log v3 -> v4
- Added previously missing #include <linux/cleanup.h>.
- Moved struct completion declaration to reduce commit diff.
MAINTAINERS | 1 +
drivers/iio/adc/Kconfig | 12 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ad4170.c | 1531 ++++++++++++++++++++++++++++++++++++++
4 files changed, 1545 insertions(+)
create mode 100644 drivers/iio/adc/ad4170.c
diff --git a/MAINTAINERS b/MAINTAINERS
index aa1e249a7b5a..c4cf97b95650 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1360,6 +1360,7 @@ L: linux-iio@vger.kernel.org
S: Supported
W: https://ez.analog.com/linux-software-drivers
F: Documentation/devicetree/bindings/iio/adc/adi,ad4170.yaml
+F: drivers/iio/adc/ad4170.c
ANALOG DEVICES INC AD4695 DRIVER
M: Michael Hennerich <michael.hennerich@analog.com>
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 3bd03df9a976..03966d07a721 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -84,6 +84,18 @@ config AD4130
To compile this driver as a module, choose M here: the module will be
called ad4130.
+
+config AD4170
+ tristate "Analog Device AD4170 ADC Driver"
+ depends on SPI
+ select REGMAP_SPI
+ help
+ Say yes here to build support for Analog Devices AD4170 SPI analog
+ to digital converters (ADC).
+
+ To compile this driver as a module, choose M here: the module will be
+ called ad4170.
+
config AD4695
tristate "Analog Device AD4695 ADC Driver"
depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 6516ccb4d63b..d99c35ff9a1c 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_AD4000) += ad4000.o
obj-$(CONFIG_AD4030) += ad4030.o
obj-$(CONFIG_AD4080) += ad4080.o
obj-$(CONFIG_AD4130) += ad4130.o
+obj-$(CONFIG_AD4170) += ad4170.o
obj-$(CONFIG_AD4695) += ad4695.o
obj-$(CONFIG_AD4851) += ad4851.o
obj-$(CONFIG_AD7091R) += ad7091r-base.o
diff --git a/drivers/iio/adc/ad4170.c b/drivers/iio/adc/ad4170.c
new file mode 100644
index 000000000000..c317529e0449
--- /dev/null
+++ b/drivers/iio/adc/ad4170.c
@@ -0,0 +1,1531 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2025 Analog Devices, Inc.
+ * Author: Ana-Maria Cusco <ana-maria.cusco@analog.com>
+ * Author: Marcelo Schmitt <marcelo.schmitt@analog.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+#include <linux/bits.h>
+#include <linux/cleanup.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/iio/iio.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/unaligned.h>
+#include <linux/units.h>
+#include <linux/util_macros.h>
+
+/*
+ * AD4170 registers
+ * Multibyte register addresses point to the most significant byte which is the
+ * address to use to get the most significant byte first (address accessed is
+ * decremented by one for each data byte)
+ *
+ * Each register address define follows the AD4170_<REG_NAME>_REG form.
+ * Each mask follows the AD4170_<REG_NAME>_<FIELD_NAME> form.
+ * E.g. AD4170_PIN_MUXING_DIG_AUX1_CTRL_MSK is for accessing DIG_AUX1_CTRL field
+ * of PIN_MUXING_REG.
+ * Each constant follows the AD4170_<REG_NAME>_<FIELD_NAME>_<FUNCTION> form.
+ * E.g. AD4170_PIN_MUXING_DIG_AUX1_DISABLED is the value written to
+ * DIG_AUX1_CTRL field of PIN_MUXING register to disable DIG_AUX1 pin.
+ * Some register names and register field names are shortened versions of
+ * their datasheet counterpart names to provide better code readability.
+ */
+#define AD4170_CONFIG_A_REG 0x00
+#define AD4170_DATA_24B_REG 0x1E
+#define AD4170_PIN_MUXING_REG 0x69
+#define AD4170_ADC_CTRL_REG 0x71
+#define AD4170_CHAN_EN_REG 0x79
+#define AD4170_CHAN_SETUP_REG(x) (0x81 + 4 * (x))
+#define AD4170_CHAN_MAP_REG(x) (0x83 + 4 * (x))
+#define AD4170_MISC_REG(x) (0xC1 + 14 * (x))
+#define AD4170_AFE_REG(x) (0xC3 + 14 * (x))
+#define AD4170_FILTER_REG(x) (0xC5 + 14 * (x))
+#define AD4170_FILTER_FS_REG(x) (0xC7 + 14 * (x))
+#define AD4170_OFFSET_REG(x) (0xCA + 14 * (x))
+#define AD4170_GAIN_REG(x) (0xCD + 14 * (x))
+
+#define AD4170_REG_READ_MASK BIT(14)
+
+/* AD4170_CONFIG_A_REG - INTERFACE_CONFIG_A REGISTER */
+#define AD4170_SW_RESET_MSK (BIT(7) | BIT(0))
+
+/* AD4170_PIN_MUXING_REG */
+#define AD4170_PIN_MUXING_DIG_AUX1_CTRL_MSK GENMASK(5, 4)
+
+/* AD4170_ADC_CTRL_REG */
+#define AD4170_ADC_CTRL_MULTI_DATA_REG_SEL_MSK BIT(7)
+#define AD4170_ADC_CTRL_MODE_MSK GENMASK(3, 0)
+
+/* AD4170_CHAN_EN_REG */
+#define AD4170_CHAN_EN(ch) BIT(ch)
+
+/* AD4170_CHAN_SETUP_REG */
+#define AD4170_CHAN_SETUP_SETUP_MSK GENMASK(2, 0)
+
+/* AD4170_CHAN_MAP_REG */
+#define AD4170_CHAN_MAP_AINP_MSK GENMASK(12, 8)
+#define AD4170_CHAN_MAP_AINM_MSK GENMASK(4, 0)
+
+/* AD4170_AFE_REG */
+#define AD4170_AFE_REF_BUF_M_MSK GENMASK(11, 10)
+#define AD4170_AFE_REF_BUF_P_MSK GENMASK(9, 8)
+#define AD4170_AFE_REF_SELECT_MSK GENMASK(6, 5)
+#define AD4170_AFE_BIPOLAR_MSK BIT(4)
+#define AD4170_AFE_PGA_GAIN_MSK GENMASK(3, 0)
+
+/* AD4170 register constants */
+
+/* AD4170_CHAN_MAP_REG constants */
+#define AD4170_CHAN_MAP_AIN(x) (x)
+#define AD4170_CHAN_MAP_TEMP_SENSOR 17
+#define AD4170_CHAN_MAP_AVDD_AVSS_P 18
+#define AD4170_CHAN_MAP_AVDD_AVSS_N 18
+#define AD4170_CHAN_MAP_IOVDD_DGND_P 19
+#define AD4170_CHAN_MAP_IOVDD_DGND_N 19
+#define AD4170_CHAN_MAP_AVSS 23
+#define AD4170_CHAN_MAP_DGND 24
+#define AD4170_CHAN_MAP_REFIN1_P 25
+#define AD4170_CHAN_MAP_REFIN1_N 26
+#define AD4170_CHAN_MAP_REFIN2_P 27
+#define AD4170_CHAN_MAP_REFIN2_N 28
+#define AD4170_CHAN_MAP_REFOUT 29
+
+/* AD4170_PIN_MUXING_REG constants */
+#define AD4170_PIN_MUXING_DIG_AUX1_DISABLED 0x0
+#define AD4170_PIN_MUXING_DIG_AUX1_RDY 0x1
+
+/* AD4170_ADC_CTRL_REG constants */
+#define AD4170_ADC_CTRL_MODE_SINGLE 0x4
+#define AD4170_ADC_CTRL_MODE_IDLE 0x7
+
+/* Device properties and auxiliary constants */
+
+#define AD4170_NUM_ANALOG_PINS 9
+#define AD4170_MAX_CHANNELS 16
+#define AD4170_MAX_ANALOG_PINS 8
+#define AD4170_MAX_SETUPS 8
+#define AD4170_INVALID_SETUP 9
+#define AD4170_SPI_MAX_XFER_LEN 6
+
+#define AD4170_INT_REF_2_5V 2500000
+
+/* Internal and external clock properties */
+#define AD4170_INT_CLOCK_16MHZ (16 * HZ_PER_MHZ)
+
+#define AD4170_NUM_PGA_OPTIONS 10
+
+#define AD4170_GAIN_REG_DEFAULT 0x555555
+
+static const unsigned int ad4170_reg_size[] = {
+ [AD4170_CONFIG_A_REG] = 1,
+ [AD4170_DATA_24B_REG] = 3,
+ [AD4170_PIN_MUXING_REG] = 2,
+ [AD4170_ADC_CTRL_REG] = 2,
+ [AD4170_CHAN_EN_REG] = 2,
+ /*
+ * CHANNEL_SETUP and CHANNEL_MAP register are all 2 byte size each and
+ * their addresses are interleaved such that we have CHANNEL_SETUP0
+ * address followed by CHANNEL_MAP0 address, followed by CHANNEL_SETUP1,
+ * and so on until CHANNEL_MAP15.
+ * Thus, initialize the register size for them only once.
+ */
+ [AD4170_CHAN_SETUP_REG(0) ... AD4170_CHAN_MAP_REG(AD4170_MAX_CHANNELS - 1)] = 2,
+ /*
+ * MISC, AFE, FILTER, FILTER_FS, OFFSET, and GAIN register addresses are
+ * also interleaved but MISC, AFE, FILTER, FILTER_FS, OFFSET are 16-bit
+ * while OFFSET, GAIN are 24-bit registers so we can't init them all to
+ * the same size.
+ */
+ [AD4170_MISC_REG(0) ... AD4170_FILTER_FS_REG(0)] = 2,
+ [AD4170_MISC_REG(1) ... AD4170_FILTER_FS_REG(1)] = 2,
+ [AD4170_MISC_REG(2) ... AD4170_FILTER_FS_REG(2)] = 2,
+ [AD4170_MISC_REG(3) ... AD4170_FILTER_FS_REG(3)] = 2,
+ [AD4170_MISC_REG(4) ... AD4170_FILTER_FS_REG(4)] = 2,
+ [AD4170_MISC_REG(5) ... AD4170_FILTER_FS_REG(5)] = 2,
+ [AD4170_MISC_REG(6) ... AD4170_FILTER_FS_REG(6)] = 2,
+ [AD4170_MISC_REG(7) ... AD4170_FILTER_FS_REG(7)] = 2,
+ [AD4170_OFFSET_REG(0) ... AD4170_GAIN_REG(0)] = 3,
+ [AD4170_OFFSET_REG(1) ... AD4170_GAIN_REG(1)] = 3,
+ [AD4170_OFFSET_REG(2) ... AD4170_GAIN_REG(2)] = 3,
+ [AD4170_OFFSET_REG(3) ... AD4170_GAIN_REG(3)] = 3,
+ [AD4170_OFFSET_REG(4) ... AD4170_GAIN_REG(4)] = 3,
+ [AD4170_OFFSET_REG(5) ... AD4170_GAIN_REG(5)] = 3,
+ [AD4170_OFFSET_REG(6) ... AD4170_GAIN_REG(6)] = 3,
+ [AD4170_OFFSET_REG(7) ... AD4170_GAIN_REG(7)] = 3,
+};
+
+enum ad4170_ref_buf {
+ AD4170_REF_BUF_PRE, /* Pre-charge referrence buffer */
+ AD4170_REF_BUF_FULL, /* Full referrence buffering */
+ AD4170_REF_BUF_BYPASS /* Bypass referrence buffering */
+};
+
+enum ad4170_ref_select {
+ AD4170_REF_REFIN1,
+ AD4170_REF_REFIN2,
+ AD4170_REF_REFOUT,
+ AD4170_REF_AVDD
+};
+
+enum ad4170_regulator {
+ AD4170_AVDD_SUP,
+ AD4170_AVSS_SUP,
+ AD4170_IOVDD_SUP,
+ AD4170_REFIN1P_SUP,
+ AD4170_REFIN1N_SUP,
+ AD4170_REFIN2P_SUP,
+ AD4170_REFIN2N_SUP,
+ AD4170_MAX_SUP
+};
+
+enum ad4170_int_pin_sel {
+ AD4170_INT_PIN_SDO,
+ AD4170_INT_PIN_DIG_AUX1,
+};
+
+static const char * const ad4170_int_pin_names[] = {
+ [AD4170_INT_PIN_SDO] = "sdo",
+ [AD4170_INT_PIN_DIG_AUX1] = "dig_aux1",
+};
+
+struct ad4170_chip_info {
+ const char *name;
+};
+
+static const struct ad4170_chip_info ad4170_chip_info = {
+ .name = "ad4170",
+};
+
+static const struct ad4170_chip_info ad4190_chip_info = {
+ .name = "ad4190",
+};
+
+static const struct ad4170_chip_info ad4195_chip_info = {
+ .name = "ad4195",
+};
+
+/*
+ * There are 8 of each MISC, AFE, FILTER, FILTER_FS, OFFSET, and GAIN
+ * configuration registers. That is, there are 8 miscellaneous registers, MISC0
+ * to MISC7. Each MISC register is associated with a setup; MISCN is associated
+ * with setup number N. The other 5 above mentioned types of registers have
+ * analogous structure. A setup is a set of those registers. For example,
+ * setup 1 comprises of MISC1, AFE1, FILTER1, FILTER_FS1, OFFSET1, and GAIN1
+ * registers. Also, there are 16 CHANNEL_SETUP registers (CHANNEL_SETUP0 to
+ * CHANNEL_SETUP15). Each channel setup is associated with one of the 8 possible
+ * setups. Thus, AD4170 can support up to 16 channels but, since there are only
+ * 8 available setups, channels must share settings if more than 8 channels are
+ * configured.
+ *
+ * If this struct is modified, ad4170_setup_eq() will probably need to be
+ * updated too.
+ */
+struct ad4170_setup {
+ u16 misc;
+ u16 afe;
+ u16 filter;
+ u16 filter_fs;
+ u32 offset; /* For calibration purposes */
+ u32 gain; /* For calibration purposes */
+};
+
+struct ad4170_setup_info {
+ struct ad4170_setup setup;
+ unsigned int enabled_channels;
+ unsigned int channels;
+};
+
+struct ad4170_chan_info {
+ unsigned int input_range_uv;
+ unsigned int setup_num; /* Index to access state setup_infos array */
+ struct ad4170_setup setup; /* cached setup */
+ int offset_tbl[10];
+ u32 scale_tbl[10][2];
+ bool initialized;
+ bool enabled;
+};
+
+struct ad4170_state {
+ struct mutex lock; /* Protect read-modify-write and multi write sequences */
+ int vrefs_uv[AD4170_MAX_SUP];
+ u32 mclk_hz;
+ struct ad4170_setup_info setup_infos[AD4170_MAX_SETUPS];
+ struct iio_chan_spec chans[AD4170_MAX_CHANNELS];
+ struct ad4170_chan_info chan_infos[AD4170_MAX_CHANNELS];
+ struct spi_device *spi;
+ struct regmap *regmap;
+ struct completion completion;
+ int pins_fn[AD4170_NUM_ANALOG_PINS];
+ u32 int_pin_sel;
+ /*
+ * DMA (thus cache coherency maintenance) requires the transfer buffers
+ * to live in their own cache lines.
+ */
+ u8 tx_buf[AD4170_SPI_MAX_XFER_LEN] __aligned(IIO_DMA_MINALIGN);
+ u8 rx_buf[4];
+};
+
+static int ad4170_debugfs_reg_access(struct iio_dev *indio_dev,
+ unsigned int reg, unsigned int writeval,
+ unsigned int *readval)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+
+ if (readval)
+ return regmap_read(st->regmap, reg, readval);
+
+ return regmap_write(st->regmap, reg, writeval);
+}
+
+static int ad4170_get_reg_size(struct ad4170_state *st, unsigned int reg,
+ unsigned int *size)
+{
+ if (reg >= ARRAY_SIZE(ad4170_reg_size))
+ return -EINVAL;
+
+ *size = ad4170_reg_size[reg];
+
+ return 0;
+}
+
+static int ad4170_reg_write(void *context, unsigned int reg, unsigned int val)
+{
+ struct ad4170_state *st = context;
+ unsigned int size;
+ int ret;
+
+ ret = ad4170_get_reg_size(st, reg, &size);
+ if (ret)
+ return ret;
+
+ put_unaligned_be16(reg, st->tx_buf);
+ switch (size) {
+ case 3:
+ put_unaligned_be24(val, &st->tx_buf[2]);
+ break;
+ case 2:
+ put_unaligned_be16(val, &st->tx_buf[2]);
+ break;
+ case 1:
+ st->tx_buf[2] = val;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return spi_write(st->spi, st->tx_buf, size + 2);
+}
+
+static int ad4170_reg_read(void *context, unsigned int reg, unsigned int *val)
+{
+ struct ad4170_state *st = context;
+ struct spi_transfer t[] = {
+ {
+ .tx_buf = st->tx_buf,
+ .len = 2,
+ },
+ {
+ .rx_buf = st->rx_buf,
+ },
+ };
+ unsigned int size;
+ int ret;
+
+ ret = ad4170_get_reg_size(st, reg, &size);
+ if (ret)
+ return ret;
+
+ put_unaligned_be16(AD4170_REG_READ_MASK | reg, st->tx_buf);
+ t[1].len = size;
+
+ ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
+ if (ret)
+ return ret;
+
+ switch (size) {
+ case 3:
+ *val = get_unaligned_be24(st->rx_buf);
+ return 0;
+ case 2:
+ *val = get_unaligned_be16(st->rx_buf);
+ return 0;
+ case 1:
+ *val = st->rx_buf[0];
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct regmap_config ad4170_regmap_config = {
+ .reg_read = ad4170_reg_read,
+ .reg_write = ad4170_reg_write,
+};
+
+static bool ad4170_setup_eq(struct ad4170_setup *a, struct ad4170_setup *b)
+{
+ /*
+ * The use of static_assert() here is to make sure that the comparison
+ * is adapted whenever struct ad4170_setup is changed.
+ */
+ static_assert(sizeof(*a) ==
+ sizeof(struct {
+ u16 misc;
+ u16 afe;
+ u16 filter;
+ u16 filter_fs;
+ u32 offset;
+ u32 gain;
+ }));
+
+ if (a->misc != b->misc ||
+ a->afe != b->afe ||
+ a->filter != b->filter ||
+ a->filter_fs != b->filter_fs ||
+ a->offset != b->offset ||
+ a->gain != b->gain)
+ return false;
+
+ return true;
+}
+
+static int ad4170_find_setup(struct ad4170_state *st,
+ struct ad4170_setup *target_setup,
+ unsigned int *setup_num, bool *overwrite)
+{
+ unsigned int i;
+
+ *setup_num = AD4170_INVALID_SETUP;
+ *overwrite = false;
+
+ for (i = 0; i < AD4170_MAX_SETUPS; i++) {
+ struct ad4170_setup_info *setup_info = &st->setup_infos[i];
+
+ /* Immediately accept a matching setup. */
+ if (ad4170_setup_eq(target_setup, &setup_info->setup)) {
+ *setup_num = i;
+ return 0;
+ }
+
+ /* Ignore all setups which are used by enabled channels. */
+ if (setup_info->enabled_channels)
+ continue;
+
+ /* Find the least used slot. */
+ if (*setup_num == AD4170_INVALID_SETUP ||
+ setup_info->channels < st->setup_infos[*setup_num].channels)
+ *setup_num = i;
+ }
+
+ if (*setup_num == AD4170_INVALID_SETUP)
+ return -EINVAL;
+
+ *overwrite = true;
+ return 0;
+}
+
+static void ad4170_unlink_channel(struct ad4170_state *st, unsigned int channel)
+{
+ struct ad4170_chan_info *chan_info = &st->chan_infos[channel];
+ struct ad4170_setup_info *setup_info = &st->setup_infos[chan_info->setup_num];
+
+ chan_info->setup_num = AD4170_INVALID_SETUP;
+ setup_info->channels--;
+}
+
+static int ad4170_unlink_setup(struct ad4170_state *st, unsigned int setup_num)
+{
+ unsigned int i;
+
+ for (i = 0; i < AD4170_MAX_CHANNELS; i++) {
+ struct ad4170_chan_info *chan_info = &st->chan_infos[i];
+
+ if (!chan_info->initialized || chan_info->setup_num != setup_num)
+ continue;
+
+ ad4170_unlink_channel(st, i);
+ }
+ return 0;
+}
+
+static int ad4170_link_channel_setup(struct ad4170_state *st,
+ unsigned int chan_addr,
+ unsigned int setup_num)
+{
+ struct ad4170_setup_info *setup_info = &st->setup_infos[setup_num];
+ struct ad4170_chan_info *chan_info = &st->chan_infos[chan_addr];
+ int ret;
+
+ ret = regmap_update_bits(st->regmap, AD4170_CHAN_SETUP_REG(chan_addr),
+ AD4170_CHAN_SETUP_SETUP_MSK,
+ FIELD_PREP(AD4170_CHAN_SETUP_SETUP_MSK, setup_num));
+ if (ret)
+ return ret;
+
+ chan_info->setup_num = setup_num;
+ setup_info->channels++;
+ return 0;
+}
+
+static int ad4170_write_setup(struct ad4170_state *st, unsigned int setup_num,
+ struct ad4170_setup *setup)
+{
+ int ret;
+
+ /*
+ * It is recommended to place the ADC in standby mode or idle mode to
+ * write to OFFSET and GAIN registers.
+ */
+ ret = regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG,
+ AD4170_ADC_CTRL_MODE_MSK,
+ FIELD_PREP(AD4170_ADC_CTRL_MODE_MSK,
+ AD4170_ADC_CTRL_MODE_IDLE));
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4170_MISC_REG(setup_num), setup->misc);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4170_AFE_REG(setup_num), setup->afe);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4170_FILTER_REG(setup_num),
+ setup->filter);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4170_FILTER_FS_REG(setup_num),
+ setup->filter_fs);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4170_OFFSET_REG(setup_num),
+ setup->offset);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4170_GAIN_REG(setup_num), setup->gain);
+ if (ret)
+ return ret;
+
+ memcpy(&st->setup_infos[setup_num].setup, setup, sizeof(*setup));
+ return 0;
+}
+
+static int ad4170_write_channel_setup(struct ad4170_state *st,
+ unsigned int chan_addr, bool on_enable)
+{
+ struct ad4170_chan_info *chan_info = &st->chan_infos[chan_addr];
+ bool overwrite;
+ int setup_num;
+ int ret;
+
+ /*
+ * Similar to AD4130 driver, the following cases need to be handled.
+ *
+ * 1. Enabled and linked channel with setup changes:
+ * - Find a setup. If not possible, return error.
+ * - Unlink channel from current setup.
+ * - If the setup found has only disabled channels linked to it,
+ * unlink all channels, and write the new setup to it.
+ * - Link channel to new setup.
+ *
+ * 2. Soon to be enabled and unlinked channel:
+ * - Find a setup. If not possible, return error.
+ * - If the setup found has only disabled channels linked to it,
+ * unlink all channels, and write the new setup to it.
+ * - Link channel to the setup.
+ *
+ * 3. Disabled and linked channel with setup changes:
+ * - Unlink channel from current setup.
+ *
+ * 4. Soon to be enabled and linked channel:
+ * 5. Disabled and unlinked channel with setup changes:
+ * - Do nothing.
+ */
+
+ /* Cases 3, 4, and 5 */
+ if (chan_info->setup_num != AD4170_INVALID_SETUP) {
+ /* Case 4 */
+ if (on_enable)
+ return 0;
+
+ /* Case 3 */
+ if (!chan_info->enabled) {
+ ad4170_unlink_channel(st, chan_addr);
+ return 0;
+ }
+ } else if (!on_enable && !chan_info->enabled) {
+ /* Case 5 */
+ return 0;
+ }
+
+ /* Cases 1 & 2 */
+ ret = ad4170_find_setup(st, &chan_info->setup, &setup_num, &overwrite);
+ if (ret)
+ return ret;
+
+ if (chan_info->setup_num != AD4170_INVALID_SETUP)
+ /* Case 1 */
+ ad4170_unlink_channel(st, chan_addr);
+
+ if (overwrite) {
+ ret = ad4170_unlink_setup(st, setup_num);
+ if (ret)
+ return ret;
+
+ ret = ad4170_write_setup(st, setup_num, &chan_info->setup);
+ if (ret)
+ return ret;
+ }
+
+ return ad4170_link_channel_setup(st, chan_addr, setup_num);
+}
+
+static int ad4170_set_channel_enable(struct ad4170_state *st,
+ unsigned int chan_addr, bool status)
+{
+ struct ad4170_chan_info *chan_info = &st->chan_infos[chan_addr];
+ struct ad4170_setup_info *setup_info;
+ int ret;
+
+ if (chan_info->enabled == status)
+ return 0;
+
+ if (status) {
+ ret = ad4170_write_channel_setup(st, chan_addr, true);
+ if (ret)
+ return ret;
+ }
+
+ setup_info = &st->setup_infos[chan_info->setup_num];
+
+ ret = regmap_update_bits(st->regmap, AD4170_CHAN_EN_REG,
+ AD4170_CHAN_EN(chan_addr),
+ status ? AD4170_CHAN_EN(chan_addr) : 0);
+ if (ret)
+ return ret;
+
+ setup_info->enabled_channels += status ? 1 : -1;
+ chan_info->enabled = status;
+ return 0;
+}
+
+static const struct iio_chan_spec ad4170_channel_template = {
+ .type = IIO_VOLTAGE,
+ .indexed = 1,
+ .differential = 1,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_OFFSET),
+ .info_mask_separate_available = BIT(IIO_CHAN_INFO_SCALE),
+ .scan_type = {
+ .realbits = 24,
+ .storagebits = 32,
+ .endianness = IIO_BE,
+ },
+};
+
+/*
+ * Receives the number of a multiplexed AD4170 input (ain_n), and stores the
+ * voltage (in µV) of the specified input into ain_voltage. If the input number
+ * is a ordinary analog input (AIN0 to AIN8), stores zero into ain_voltage.
+ * If a voltage regulator required by a special input is unavailable, return
+ * error code. Return 0 on success.
+ */
+static int ad4170_get_ain_voltage_uv(struct ad4170_state *st, int ain_n,
+ int *ain_voltage)
+{
+ struct device *dev = &st->spi->dev;
+ int v_diff;
+
+ *ain_voltage = 0;
+ if (ain_n <= AD4170_CHAN_MAP_TEMP_SENSOR)
+ return 0;
+
+ switch (ain_n) {
+ case AD4170_CHAN_MAP_AVDD_AVSS_N:
+ v_diff = st->vrefs_uv[AD4170_AVDD_SUP] - st->vrefs_uv[AD4170_AVSS_SUP];
+ *ain_voltage = v_diff / 5;
+ return 0;
+ case AD4170_CHAN_MAP_IOVDD_DGND_N:
+ *ain_voltage = st->vrefs_uv[AD4170_IOVDD_SUP] / 5;
+ return 0;
+ case AD4170_CHAN_MAP_AVSS:
+ *ain_voltage = st->vrefs_uv[AD4170_AVSS_SUP];
+ return 0;
+ case AD4170_CHAN_MAP_DGND:
+ *ain_voltage = 0;
+ return 0;
+ case AD4170_CHAN_MAP_REFIN1_P:
+ if (st->vrefs_uv[AD4170_REFIN1P_SUP] == -ENODEV)
+ return dev_err_probe(dev, -ENODEV,
+ "input set to REFIN+ but ref not provided\n");
+
+ *ain_voltage = st->vrefs_uv[AD4170_REFIN1P_SUP];
+ return 0;
+ case AD4170_CHAN_MAP_REFIN1_N:
+ if (st->vrefs_uv[AD4170_REFIN1N_SUP] == -ENODEV)
+ return dev_err_probe(dev, -ENODEV,
+ "input set to REFIN- but ref not provided\n");
+
+ *ain_voltage = st->vrefs_uv[AD4170_REFIN1N_SUP];
+ return 0;
+ case AD4170_CHAN_MAP_REFIN2_P:
+ if (st->vrefs_uv[AD4170_REFIN2P_SUP] == -ENODEV)
+ return dev_err_probe(dev, -ENODEV,
+ "input set to REFIN2+ but ref not provided\n");
+
+ *ain_voltage = st->vrefs_uv[AD4170_REFIN2P_SUP];
+ return 0;
+ case AD4170_CHAN_MAP_REFIN2_N:
+ if (st->vrefs_uv[AD4170_REFIN2N_SUP] == -ENODEV)
+ return dev_err_probe(dev, -ENODEV,
+ "input set to REFIN2- but ref not provided\n");
+
+ *ain_voltage = st->vrefs_uv[AD4170_REFIN2N_SUP];
+ return 0;
+ case AD4170_CHAN_MAP_REFOUT:
+ /* REFOUT is 2.5V relative to AVSS so take that into account */
+ *ain_voltage = st->vrefs_uv[AD4170_AVSS_SUP] + AD4170_INT_REF_2_5V;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad4170_validate_channel_input(struct ad4170_state *st, int pin, bool com)
+{
+ /* Check common-mode input pin is mapped to a special input. */
+ if (com && (pin < AD4170_CHAN_MAP_AVDD_AVSS_P || pin > AD4170_CHAN_MAP_REFOUT))
+ return dev_err_probe(&st->spi->dev, -EINVAL,
+ "Invalid common-mode input pin number. %d\n",
+ pin);
+
+ /* Check differential input pin is mapped to a analog input pin. */
+ if (!com && pin > AD4170_MAX_ANALOG_PINS)
+ return dev_err_probe(&st->spi->dev, -EINVAL,
+ "Invalid analog input pin number. %d\n",
+ pin);
+
+ return 0;
+}
+
+/*
+ * Verifies whether the channel input configuration is valid by checking the
+ * input numbers.
+ * Returns 0 on valid channel input configuration. -EINVAL otherwise.
+ */
+static int ad4170_validate_channel(struct ad4170_state *st,
+ struct iio_chan_spec const *chan)
+{
+ int ret;
+
+ ret = ad4170_validate_channel_input(st, chan->channel, false);
+ if (ret)
+ return ret;
+
+ return ad4170_validate_channel_input(st, chan->channel2,
+ !chan->differential);
+}
+
+/*
+ * Verifies whether the channel configuration is valid by checking the provided
+ * input type, polarity, and voltage references result in a sane input range.
+ * Returns negative error code on failure.
+ */
+static int ad4170_get_input_range(struct ad4170_state *st,
+ struct iio_chan_spec const *chan,
+ unsigned int ch_reg, unsigned int ref_sel)
+{
+ bool bipolar = chan->scan_type.sign == 's';
+ struct device *dev = &st->spi->dev;
+ int refp, refn, ain_voltage, ret;
+
+ switch (ref_sel) {
+ case AD4170_REF_REFIN1:
+ if (st->vrefs_uv[AD4170_REFIN1P_SUP] == -ENODEV ||
+ st->vrefs_uv[AD4170_REFIN1N_SUP] == -ENODEV)
+ return dev_err_probe(dev, -ENODEV,
+ "REFIN± selected but not provided\n");
+
+ refp = st->vrefs_uv[AD4170_REFIN1P_SUP];
+ refn = st->vrefs_uv[AD4170_REFIN1N_SUP];
+ break;
+ case AD4170_REF_REFIN2:
+ if (st->vrefs_uv[AD4170_REFIN2P_SUP] == -ENODEV ||
+ st->vrefs_uv[AD4170_REFIN2N_SUP] == -ENODEV)
+ return dev_err_probe(dev, -ENODEV,
+ "REFIN2± selected but not provided\n");
+
+ refp = st->vrefs_uv[AD4170_REFIN2P_SUP];
+ refn = st->vrefs_uv[AD4170_REFIN2N_SUP];
+ break;
+ case AD4170_REF_AVDD:
+ refp = st->vrefs_uv[AD4170_AVDD_SUP];
+ refn = st->vrefs_uv[AD4170_AVSS_SUP];
+ break;
+ case AD4170_REF_REFOUT:
+ /* REFOUT is 2.5 V relative to AVSS */
+ refp = st->vrefs_uv[AD4170_AVSS_SUP] + AD4170_INT_REF_2_5V;
+ refn = st->vrefs_uv[AD4170_AVSS_SUP];
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /*
+ * Find out the analog input range from the channel type, polarity, and
+ * voltage reference selection.
+ * AD4170 channels are either differential or pseudo-differential.
+ * Diff input voltage range: −VREF/gain to +VREF/gain (datasheet page 6)
+ * Pseudo-diff input voltage range: 0 to VREF/gain (datasheet page 6)
+ */
+ if (chan->differential) {
+ if (!bipolar)
+ return dev_err_probe(dev, -EINVAL,
+ "Channel %u differential unipolar\n",
+ ch_reg);
+
+ /*
+ * Differential bipolar channel.
+ * avss-supply is never above 0V.
+ * Assuming refin1n-supply not above 0V.
+ * Assuming refin2n-supply not above 0V.
+ */
+ return refp + abs(refn);
+ }
+ /*
+ * Some configurations can lead to invalid setups.
+ * For example, if AVSS = -2.5V, REF_SELECT set to REFOUT (REFOUT/AVSS),
+ * and pseudo-diff channel configuration set, then the input range
+ * should go from 0V to +VREF (single-ended - datasheet pg 10), but
+ * REFOUT/AVSS range would be -2.5V to 0V.
+ * Check the positive reference is higher than 0V for pseudo-diff
+ * channels.
+ */
+ if (refp <= 0)
+ return dev_err_probe(dev, -EINVAL,
+ "REF+ <= GND for pseudo-diff chan %u\n",
+ ch_reg);
+
+ if (bipolar)
+ return refp;
+
+ /*
+ * Pseudo-differential unipolar channel.
+ * Input expected to swing from IN- to +VREF.
+ */
+ ret = ad4170_get_ain_voltage_uv(st, chan->channel2, &ain_voltage);
+ if (ret)
+ return ret;
+
+ if (refp - ain_voltage <= 0)
+ return dev_err_probe(dev, -EINVAL,
+ "Negative input >= REF+ for pseudo-diff chan %u\n",
+ ch_reg);
+
+ return refp - ain_voltage;
+}
+
+static int __ad4170_read_sample(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ unsigned long settling_time_ms;
+ int ret;
+
+ reinit_completion(&st->completion);
+ ret = regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG,
+ AD4170_ADC_CTRL_MODE_MSK,
+ FIELD_PREP(AD4170_ADC_CTRL_MODE_MSK,
+ AD4170_ADC_CTRL_MODE_SINGLE));
+ if (ret)
+ return ret;
+
+ /*
+ * When a channel is manually selected by the user, the ADC needs an
+ * extra time to provide the first stable conversion. The ADC settling
+ * time depends on the filter type, filter frequency, and ADC clock
+ * frequency (see datasheet page 53). The maximum settling time among
+ * all filter configurations is 6291164 / fCLK. Use that formula to wait
+ * for sufficient time whatever the filter configuration may be.
+ */
+ settling_time_ms = DIV_ROUND_UP(6291164 * MILLI, st->mclk_hz);
+ ret = wait_for_completion_timeout(&st->completion,
+ msecs_to_jiffies(settling_time_ms));
+ if (!ret)
+ dev_dbg(&st->spi->dev,
+ "No Data Ready signal. Reading after delay.\n");
+
+ ret = regmap_read(st->regmap, AD4170_DATA_24B_REG, val);
+ if (ret)
+ return ret;
+
+ if (chan->scan_type.sign == 's')
+ *val = sign_extend32(*val, chan->scan_type.realbits - 1);
+
+ return 0;
+}
+
+static int ad4170_read_sample(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct device *dev = &st->spi->dev;
+ int ret, ret2;
+
+ /*
+ * The ADC sequences through all enabled channels. That can lead to
+ * incorrect channel being sampled if a previous read would have left a
+ * different channel enabled. Thus, always enable and disable the
+ * channel on single-shot read.
+ */
+ ret = ad4170_set_channel_enable(st, chan->address, true);
+ if (ret)
+ return ret;
+
+ ret = __ad4170_read_sample(indio_dev, chan, val);
+ if (ret) {
+ dev_err(dev, "failed to read sample: %d\n", ret);
+
+ ret2 = ad4170_set_channel_enable(st, chan->address, false);
+ if (ret2)
+ dev_err(dev, "failed to disable channel: %d\n", ret2);
+
+ return ret;
+ }
+
+ ret = ad4170_set_channel_enable(st, chan->address, false);
+ if (ret)
+ return ret;
+
+ return IIO_VAL_INT;
+}
+
+static int ad4170_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long info)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
+ struct ad4170_setup *setup = &chan_info->setup;
+ unsigned int pga;
+ int ret;
+
+ guard(mutex)(&st->lock);
+ switch (info) {
+ case IIO_CHAN_INFO_RAW:
+ if (!iio_device_claim_direct(indio_dev))
+ return -EBUSY;
+
+ ret = ad4170_read_sample(indio_dev, chan, val);
+ iio_device_release_direct(indio_dev);
+ return ret;
+ case IIO_CHAN_INFO_SCALE:
+ pga = FIELD_GET(AD4170_AFE_PGA_GAIN_MSK, setup->afe);
+ *val = chan_info->scale_tbl[pga][0];
+ *val2 = chan_info->scale_tbl[pga][1];
+ return IIO_VAL_INT_PLUS_NANO;
+ case IIO_CHAN_INFO_OFFSET:
+ pga = FIELD_GET(AD4170_AFE_PGA_GAIN_MSK, setup->afe);
+ *val = chan_info->offset_tbl[pga];
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad4170_fill_scale_tbl(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
+ struct device *dev = &st->spi->dev;
+ int bipolar = chan->scan_type.sign == 's' ? 1 : 0;
+ int precision_bits = chan->scan_type.realbits;
+ int pga, ainm_voltage, ret;
+ unsigned long long offset;
+
+ ainm_voltage = 0;
+ ret = ad4170_get_ain_voltage_uv(st, chan->channel2, &ainm_voltage);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Failed to fill scale table\n");
+
+ for (pga = 0; pga < AD4170_NUM_PGA_OPTIONS; pga++) {
+ u64 nv;
+ unsigned int lshift, rshift;
+
+ /*
+ * The PGA options are numbered from 0 to 9, with option 0 being
+ * a gain of 2^0 (no actual gain), and 7 meaning a gain of 2^7.
+ * Option 8, though, sets a gain of 0.5, so the input signal can
+ * be attenuated by 2 rather than amplified. Option 9, allows
+ * the signal to bypass the PGA circuitry (no gain).
+ *
+ * The scale factor to get ADC output codes to values in mV
+ * units is given by:
+ * _scale = (input_range / gain) / 2^precision
+ * AD4170 gain is a power of 2 so the above can be written as
+ * _scale = input_range / 2^(precision + gain)
+ * Keep the input range in µV to avoid truncating the less
+ * significan bits when right shifting it so to preserve scale
+ * precision.
+ */
+ nv = (u64)chan_info->input_range_uv * NANO;
+ lshift = !!(pga & BIT(3)); /* handle options 8 and 9 */
+ rshift = precision_bits - bipolar + (pga & GENMASK(2, 0)) - lshift;
+ chan_info->scale_tbl[pga][0] = 0;
+ chan_info->scale_tbl[pga][1] = div_u64(nv >> rshift, MILLI);
+
+ /*
+ * If the negative input is not at GND, the conversion result
+ * (which is relative to IN-) will be offset by the level at IN-.
+ * Use the scale factor the other way around to go from a known
+ * voltage to the corresponding ADC output code.
+ * With that, we are able to get to what would be the output
+ * code for the voltage at the negative input.
+ * If the negative input is not fixed, there is no offset.
+ */
+ offset = ((unsigned long long)abs(ainm_voltage)) * MICRO;
+ offset = DIV_ROUND_CLOSEST_ULL(offset, chan_info->scale_tbl[pga][1]);
+
+ /*
+ * After divided by the scale, offset will always fit into 31
+ * bits. For _raw + _offset to be relative to GND, the value
+ * provided as _offset is of opposite sign than the real offset.
+ */
+ if (ainm_voltage > 0)
+ chan_info->offset_tbl[pga] = -(int)(offset);
+ else
+ chan_info->offset_tbl[pga] = (int)(offset);
+ }
+ return 0;
+}
+
+static int ad4170_read_avail(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ const int **vals, int *type, int *length,
+ long info)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
+
+ switch (info) {
+ case IIO_CHAN_INFO_SCALE:
+ *vals = (int *)chan_info->scale_tbl;
+ *length = ARRAY_SIZE(chan_info->scale_tbl) * 2;
+ *type = IIO_VAL_INT_PLUS_NANO;
+ return IIO_AVAIL_LIST;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad4170_set_pga(struct ad4170_state *st,
+ struct iio_chan_spec const *chan, int val, int val2)
+{
+ struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
+ struct ad4170_setup *setup = &chan_info->setup;
+ unsigned int pga;
+
+ for (pga = 0; pga < AD4170_NUM_PGA_OPTIONS; pga++) {
+ if (val == chan_info->scale_tbl[pga][0] &&
+ val2 == chan_info->scale_tbl[pga][1])
+ break;
+ }
+
+ if (pga == AD4170_NUM_PGA_OPTIONS)
+ return -EINVAL;
+
+ guard(mutex)(&st->lock);
+ setup->afe &= ~AD4170_AFE_PGA_GAIN_MSK;
+ setup->afe |= FIELD_PREP(AD4170_AFE_PGA_GAIN_MSK, pga);
+
+ return ad4170_write_channel_setup(st, chan->address, false);
+}
+
+static int __ad4170_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int val,
+ int val2, long info)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+
+ switch (info) {
+ case IIO_CHAN_INFO_SCALE:
+ return ad4170_set_pga(st, chan, val, val2);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad4170_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int val,
+ int val2, long info)
+{
+ int ret;
+
+ if (!iio_device_claim_direct(indio_dev))
+ return -EBUSY;
+
+ ret = __ad4170_write_raw(indio_dev, chan, val, val2, info);
+ iio_device_release_direct(indio_dev);
+ return ret;
+}
+
+static int ad4170_write_raw_get_fmt(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ long info)
+{
+ switch (info) {
+ case IIO_CHAN_INFO_SCALE:
+ return IIO_VAL_INT_PLUS_NANO;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info ad4170_info = {
+ .read_raw = ad4170_read_raw,
+ .read_avail = ad4170_read_avail,
+ .write_raw = ad4170_write_raw,
+ .write_raw_get_fmt = ad4170_write_raw_get_fmt,
+ .debugfs_reg_access = ad4170_debugfs_reg_access,
+};
+
+static int ad4170_soft_reset(struct ad4170_state *st)
+{
+ int ret;
+
+ ret = regmap_write(st->regmap, AD4170_CONFIG_A_REG,
+ AD4170_SW_RESET_MSK);
+ if (ret)
+ return ret;
+
+ /* AD4170-4 requires 1 ms between reset and any register access. */
+ fsleep(MILLI);
+
+ return 0;
+}
+
+static int ad4170_parse_reference(struct ad4170_state *st,
+ struct fwnode_handle *child,
+ struct ad4170_setup *setup)
+{
+ struct device *dev = &st->spi->dev;
+ int ret;
+ u32 aux;
+
+ /* Optional positive reference buffering */
+ aux = AD4170_REF_BUF_FULL; /* Default to full precharge buffer enabled. */
+ fwnode_property_read_u32(child, "adi,positive-reference-buffer", &aux);
+ if (aux < AD4170_REF_BUF_PRE || aux > AD4170_REF_BUF_BYPASS)
+ return dev_err_probe(dev, -EINVAL,
+ "Invalid adi,positive-reference-buffer: %u\n",
+ aux);
+
+ setup->afe |= FIELD_PREP(AD4170_AFE_REF_BUF_P_MSK, aux);
+
+ /* Optional negative reference buffering */
+ aux = AD4170_REF_BUF_FULL; /* Default to full precharge buffer enabled. */
+ fwnode_property_read_u32(child, "adi,negative-reference-buffer", &aux);
+ if (aux < AD4170_REF_BUF_PRE || aux > AD4170_REF_BUF_BYPASS)
+ return dev_err_probe(dev, -EINVAL,
+ "Invalid adi,negative-reference-buffer: %u\n",
+ aux);
+
+ setup->afe |= FIELD_PREP(AD4170_AFE_REF_BUF_M_MSK, aux);
+
+ /* Optional voltage reference selection */
+ aux = AD4170_REF_REFOUT; /* Default reference selection. */
+ ret = fwnode_property_read_u32(child, "adi,reference-select", &aux);
+ if (aux > AD4170_REF_AVDD)
+ return dev_err_probe(dev, -EINVAL,
+ "Invalid reference selected %u\n",
+ aux);
+
+ setup->afe |= FIELD_PREP(AD4170_AFE_REF_SELECT_MSK, aux);
+
+ return 0;
+}
+
+static int ad4170_parse_adc_channel_type(struct device *dev,
+ struct fwnode_handle *child,
+ struct iio_chan_spec *chan)
+{
+ int ret, ret2;
+ u32 pins[2];
+
+ /* Parse pseudo-differential channel configuration */
+ ret = fwnode_property_read_u32(child, "single-channel", &pins[0]);
+ ret2 = fwnode_property_read_u32(child, "common-mode-channel", &pins[1]);
+ if (!ret && ret2)
+ return dev_err_probe(dev, ret,
+ "single-ended channels must define common-mode-channel\n");
+
+ if (!ret && !ret2) {
+ chan->differential = false;
+ chan->channel = pins[0];
+ chan->channel2 = pins[1];
+ return 0;
+ }
+ /* Failed to parse pseudo-diff chan props so try diff chan */
+
+ /* Parse differential channel configuration */
+ ret = fwnode_property_read_u32_array(child, "diff-channels", pins,
+ ARRAY_SIZE(pins));
+ if (!ret) {
+ chan->differential = true;
+ chan->channel = pins[0];
+ chan->channel2 = pins[1];
+ return 0;
+ }
+ return dev_err_probe(dev, ret,
+ "Channel must define one of diff-channels or single-channel.\n");
+}
+
+static int ad4170_parse_channel_node(struct iio_dev *indio_dev,
+ struct fwnode_handle *child,
+ unsigned int chan_num)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct device *dev = &st->spi->dev;
+ struct ad4170_chan_info *chan_info;
+ struct ad4170_setup *setup;
+ struct iio_chan_spec *chan;
+ unsigned int ch_reg;
+ u8 ref_select;
+ bool bipolar;
+ int ret;
+
+ ret = fwnode_property_read_u32(child, "reg", &ch_reg);
+ if (ret)
+ return dev_err_probe(dev, -EINVAL,
+ "Failed to read channel reg\n");
+
+ if (ch_reg >= AD4170_MAX_CHANNELS)
+ return dev_err_probe(dev, -EINVAL,
+ "Channel idx greater than no of channels\n");
+
+ chan = &st->chans[chan_num];
+ *chan = ad4170_channel_template;
+
+ chan->address = ch_reg;
+ chan->scan_index = ch_reg;
+ chan_info = &st->chan_infos[chan->address];
+
+ chan_info->setup_num = AD4170_INVALID_SETUP;
+ chan_info->initialized = true;
+
+ setup = &chan_info->setup;
+ ret = ad4170_parse_reference(st, child, setup);
+ if (ret)
+ return ret;
+
+ ret = ad4170_parse_adc_channel_type(dev, child, chan);
+ if (ret < 0)
+ return ret;
+
+ bipolar = fwnode_property_read_bool(child, "bipolar");
+ setup->afe |= FIELD_PREP(AD4170_AFE_BIPOLAR_MSK, bipolar);
+ if (bipolar)
+ chan->scan_type.sign = 's';
+ else
+ chan->scan_type.sign = 'u';
+
+ ref_select = FIELD_GET(AD4170_AFE_REF_SELECT_MSK, setup->afe);
+ ret = ad4170_validate_channel(st, chan);
+ if (ret < 0)
+ return ret;
+
+ ret = ad4170_get_input_range(st, chan, ch_reg, ref_select);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Invalid input config\n");
+
+ chan_info->input_range_uv = ret;
+ return 0;
+}
+
+static int ad4170_parse_channels(struct iio_dev *indio_dev)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct device *dev = &st->spi->dev;
+ unsigned int num_channels;
+ unsigned int chan_num = 0;
+ int ret;
+
+ num_channels = device_get_child_node_count(dev);
+
+ if (num_channels > AD4170_MAX_CHANNELS)
+ return dev_err_probe(dev, -EINVAL, "Too many channels\n");
+
+ device_for_each_child_node_scoped(dev, child) {
+ ret = ad4170_parse_channel_node(indio_dev, child, chan_num++);
+ if (ret)
+ return ret;
+ }
+
+ indio_dev->num_channels = num_channels;
+ indio_dev->channels = st->chans;
+
+ return 0;
+}
+
+static int ad4170_parse_firmware(struct iio_dev *indio_dev)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct device *dev = &st->spi->dev;
+ int reg_data, ret;
+
+ st->mclk_hz = AD4170_INT_CLOCK_16MHZ;
+
+ /* On power on, device defaults to using SDO pin for data ready signal */
+ st->int_pin_sel = AD4170_INT_PIN_SDO;
+ ret = device_property_match_property_string(dev, "interrupt-names",
+ ad4170_int_pin_names,
+ ARRAY_SIZE(ad4170_int_pin_names));
+ if (ret >= 0)
+ st->int_pin_sel = ret;
+
+ reg_data = FIELD_PREP(AD4170_PIN_MUXING_DIG_AUX1_CTRL_MSK,
+ st->int_pin_sel == AD4170_INT_PIN_DIG_AUX1 ?
+ AD4170_PIN_MUXING_DIG_AUX1_RDY :
+ AD4170_PIN_MUXING_DIG_AUX1_DISABLED);
+
+ ret = regmap_update_bits(st->regmap, AD4170_PIN_MUXING_REG,
+ AD4170_PIN_MUXING_DIG_AUX1_CTRL_MSK, reg_data);
+ if (ret)
+ return ret;
+
+ return ad4170_parse_channels(indio_dev);
+}
+
+static int ad4170_initial_config(struct iio_dev *indio_dev)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct device *dev = &st->spi->dev;
+ unsigned int i;
+ int ret;
+
+ ret = regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG,
+ AD4170_ADC_CTRL_MODE_MSK,
+ FIELD_PREP(AD4170_ADC_CTRL_MODE_MSK,
+ AD4170_ADC_CTRL_MODE_IDLE));
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to set ADC mode to idle\n");
+
+ for (i = 0; i < indio_dev->num_channels; i++) {
+ struct ad4170_chan_info *chan_info;
+ struct iio_chan_spec const *chan;
+ struct ad4170_setup *setup;
+ unsigned int val;
+
+ chan = &indio_dev->channels[i];
+ chan_info = &st->chan_infos[chan->address];
+
+ setup = &chan_info->setup;
+ setup->gain = AD4170_GAIN_REG_DEFAULT;
+ ret = ad4170_write_channel_setup(st, chan->address, false);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to write channel setup\n");
+
+ val = FIELD_PREP(AD4170_CHAN_MAP_AINP_MSK, chan->channel) |
+ FIELD_PREP(AD4170_CHAN_MAP_AINM_MSK, chan->channel2);
+
+ ret = regmap_write(st->regmap, AD4170_CHAN_MAP_REG(i), val);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to write CHAN_MAP_REG\n");
+
+ ret = ad4170_fill_scale_tbl(indio_dev, chan);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to fill scale tbl\n");
+ }
+
+ /* Disable all channels to avoid reading from unexpected channel */
+ ret = regmap_write(st->regmap, AD4170_CHAN_EN_REG, 0);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to disable channels\n");
+
+ /*
+ * Configure channels to share the same data output register, i.e. data
+ * can be read from the same register address regardless of channel
+ * number.
+ */
+ return regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG,
+ AD4170_ADC_CTRL_MULTI_DATA_REG_SEL_MSK,
+ AD4170_ADC_CTRL_MULTI_DATA_REG_SEL_MSK);
+}
+
+static irqreturn_t ad4170_irq_handler(int irq, void *dev_id)
+{
+ struct iio_dev *indio_dev = dev_id;
+ struct ad4170_state *st = iio_priv(indio_dev);
+
+ complete(&st->completion);
+
+ return IRQ_HANDLED;
+};
+
+static int ad4170_regulator_setup(struct ad4170_state *st)
+{
+ struct device *dev = &st->spi->dev;
+ int ret;
+
+ /* Required regulators */
+ ret = devm_regulator_get_enable_read_voltage(dev, "avdd");
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Failed to get AVDD voltage.\n");
+
+ st->vrefs_uv[AD4170_AVDD_SUP] = ret;
+
+ ret = devm_regulator_get_enable_read_voltage(dev, "iovdd");
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Failed to get IOVDD voltage.\n");
+
+ st->vrefs_uv[AD4170_IOVDD_SUP] = ret;
+
+ /* Optional regulators */
+ ret = devm_regulator_get_enable_read_voltage(dev, "avss");
+ if (ret < 0 && ret != -ENODEV)
+ return dev_err_probe(dev, ret, "Failed to get AVSS voltage.\n");
+
+ /* Assume AVSS at GND (0V) if not provided */
+ st->vrefs_uv[AD4170_AVSS_SUP] = ret == -ENODEV ? 0 : -ret;
+
+ ret = devm_regulator_get_enable_read_voltage(dev, "refin1p");
+ if (ret < 0 && ret != -ENODEV)
+ return dev_err_probe(dev, ret, "Failed to get REFIN+ voltage.\n");
+
+ st->vrefs_uv[AD4170_REFIN1P_SUP] = ret;
+
+ ret = devm_regulator_get_enable_read_voltage(dev, "refin1n");
+ if (ret < 0 && ret != -ENODEV)
+ return dev_err_probe(dev, ret, "Failed to get REFIN- voltage.\n");
+
+ /* Negative supplies are assumed to provide negative voltage */
+ st->vrefs_uv[AD4170_REFIN1N_SUP] = ret == -ENODEV ? -ENODEV : -ret;
+
+ ret = devm_regulator_get_enable_read_voltage(dev, "refin2p");
+ if (ret < 0 && ret != -ENODEV)
+ return dev_err_probe(dev, ret, "Failed to get REFIN2+ voltage.\n");
+
+ st->vrefs_uv[AD4170_REFIN2P_SUP] = ret;
+
+ ret = devm_regulator_get_enable_read_voltage(dev, "refin2n");
+ if (ret < 0 && ret != -ENODEV)
+ return dev_err_probe(dev, ret, "Failed to get REFIN2- voltage.\n");
+
+ /* Negative supplies are assumed to provide negative voltage */
+ st->vrefs_uv[AD4170_REFIN2N_SUP] = ret == -ENODEV ? -ENODEV : -ret;
+
+ return 0;
+}
+
+static int ad4170_probe(struct spi_device *spi)
+{
+ const struct ad4170_chip_info *chip;
+ struct device *dev = &spi->dev;
+ struct iio_dev *indio_dev;
+ struct ad4170_state *st;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+ ret = devm_mutex_init(dev, &st->lock);
+ if (ret)
+ return ret;
+
+ chip = spi_get_device_match_data(spi);
+ if (!chip)
+ return -EINVAL;
+
+ indio_dev->name = chip->name;
+ indio_dev->info = &ad4170_info;
+
+ st->spi = spi;
+
+ st->regmap = devm_regmap_init(dev, NULL, st, &ad4170_regmap_config);
+ if (IS_ERR(st->regmap))
+ return dev_err_probe(dev, PTR_ERR(st->regmap),
+ "Failed to initialize regmap\n");
+
+ ret = ad4170_regulator_setup(st);
+ if (ret)
+ return ret;
+
+ ret = ad4170_soft_reset(st);
+ if (ret)
+ return ret;
+
+ ret = ad4170_parse_firmware(indio_dev);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to parse firmware\n");
+
+ ret = ad4170_initial_config(indio_dev);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to setup device\n");
+
+ init_completion(&st->completion);
+
+ if (spi->irq) {
+ ret = devm_request_irq(dev, spi->irq, &ad4170_irq_handler,
+ IRQF_ONESHOT, indio_dev->name, indio_dev);
+ if (ret)
+ return ret;
+ }
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct spi_device_id ad4170_id_table[] = {
+ { "ad4170", (kernel_ulong_t)&ad4170_chip_info },
+ { "ad4190", (kernel_ulong_t)&ad4190_chip_info },
+ { "ad4195", (kernel_ulong_t)&ad4195_chip_info },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, ad4170_id_table);
+
+static const struct of_device_id ad4170_of_match[] = {
+ { .compatible = "adi,ad4170", .data = &ad4170_chip_info },
+ { .compatible = "adi,ad4190", .data = &ad4190_chip_info },
+ { .compatible = "adi,ad4195", .data = &ad4195_chip_info },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ad4170_of_match);
+
+static struct spi_driver ad4170_driver = {
+ .driver = {
+ .name = "ad4170",
+ .of_match_table = ad4170_of_match,
+ },
+ .probe = ad4170_probe,
+ .id_table = ad4170_id_table,
+};
+module_spi_driver(ad4170_driver);
+
+MODULE_AUTHOR("Ana-Maria Cusco <ana-maria.cusco@analog.com>");
+MODULE_AUTHOR("Marcelo Schmitt <marcelo.schmitt@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD4170 SPI driver");
+MODULE_LICENSE("GPL");
--
2.47.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* Re: [PATCH v4 02/11] iio: adc: Add basic support for AD4170
2025-06-02 11:36 ` [PATCH v4 02/11] iio: adc: Add basic support for AD4170 Marcelo Schmitt
@ 2025-06-02 14:55 ` Andy Shevchenko
2025-06-02 16:54 ` Marcelo Schmitt
2025-06-03 14:00 ` kernel test robot
1 sibling, 1 reply; 29+ messages in thread
From: Andy Shevchenko @ 2025-06-02 14:55 UTC (permalink / raw)
To: Marcelo Schmitt
Cc: linux-iio, devicetree, linux-gpio, linux-kernel, Ana-Maria Cusco,
jic23, lars, Michael.Hennerich, dlechner, nuno.sa, robh, krzk+dt,
conor+dt, linus.walleij, brgl, marcelo.schmitt1
On Mon, Jun 02, 2025 at 08:36:47AM -0300, Marcelo Schmitt wrote:
> From: Ana-Maria Cusco <ana-maria.cusco@analog.com>
>
> The AD4170 is a multichannel, low noise, 24-bit precision sigma-delta
> analog to digital converter. The AD4170 design offers a flexible data
> acquisition solution with crosspoint multiplexed analog inputs,
> configurable ADC voltage reference inputs, ultra-low noise integrated PGA,
> digital filtering, wide range of configurable output data rates, internal
> oscillator and temperature sensor, four GPIOs, and integrated features for
> interfacing with load cell weigh scales, RTD, and thermocouple sensors.
>
> Add basic support for the AD4170 ADC with the following features:
> - Single-shot read.
> - Analog front end PGA configuration.
> - Differential and pseudo-differential input configuration.
...
+ array_size.h
> +#include <linux/bitfield.h>
> +#include <linux/bitmap.h>
> +#include <linux/bitops.h>
> +#include <linux/bits.h>
bitmap.h guarantees to include the two above, but it;s not a big deal to leave
them.
> +#include <linux/cleanup.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/iio/iio.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/math64.h>
> +#include <linux/module.h>
> +#include <linux/property.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/spi/spi.h>
+ types.h
> +#include <linux/unaligned.h>
> +#include <linux/units.h>
> +#include <linux/util_macros.h>
...
> +static bool ad4170_setup_eq(struct ad4170_setup *a, struct ad4170_setup *b)
> +{
> + /*
> + * The use of static_assert() here is to make sure that the comparison
> + * is adapted whenever struct ad4170_setup is changed.
> + */
> + static_assert(sizeof(*a) ==
> + sizeof(struct {
> + u16 misc;
> + u16 afe;
> + u16 filter;
> + u16 filter_fs;
> + u32 offset;
> + u32 gain;
> + }));
I think it doesn't make much sense unless one uses memcpy().
> + if (a->misc != b->misc ||
> + a->afe != b->afe ||
> + a->filter != b->filter ||
> + a->filter_fs != b->filter_fs ||
> + a->offset != b->offset ||
> + a->gain != b->gain)
> + return false;
> +
> + return true;
> +}
...
> +static int ad4170_soft_reset(struct ad4170_state *st)
> +{
> + int ret;
> +
> + ret = regmap_write(st->regmap, AD4170_CONFIG_A_REG,
> + AD4170_SW_RESET_MSK);
> + if (ret)
> + return ret;
> +
> + /* AD4170-4 requires 1 ms between reset and any register access. */
> + fsleep(MILLI);
1 * USEC_PER_MSEC
(need time.h)
...
> + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + st = iio_priv(indio_dev);
+ blank line here.
> + ret = devm_mutex_init(dev, &st->lock);
> + if (ret)
> + return ret;
> + chip = spi_get_device_match_data(spi);
> + if (!chip)
> + return -EINVAL;
> +
> + indio_dev->name = chip->name;
> + indio_dev->info = &ad4170_info;
> + st->spi = spi;
Can be grouped with above st = ...
> + st->regmap = devm_regmap_init(dev, NULL, st, &ad4170_regmap_config);
> + if (IS_ERR(st->regmap))
> + return dev_err_probe(dev, PTR_ERR(st->regmap),
> + "Failed to initialize regmap\n");
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [PATCH v4 02/11] iio: adc: Add basic support for AD4170
2025-06-02 14:55 ` Andy Shevchenko
@ 2025-06-02 16:54 ` Marcelo Schmitt
2025-06-03 8:27 ` Andy Shevchenko
0 siblings, 1 reply; 29+ messages in thread
From: Marcelo Schmitt @ 2025-06-02 16:54 UTC (permalink / raw)
To: Andy Shevchenko
Cc: Marcelo Schmitt, linux-iio, devicetree, linux-gpio, linux-kernel,
Ana-Maria Cusco, jic23, lars, Michael.Hennerich, dlechner,
nuno.sa, robh, krzk+dt, conor+dt, linus.walleij, brgl
...
> > +static bool ad4170_setup_eq(struct ad4170_setup *a, struct ad4170_setup *b)
> > +{
> > + /*
> > + * The use of static_assert() here is to make sure that the comparison
> > + * is adapted whenever struct ad4170_setup is changed.
> > + */
> > + static_assert(sizeof(*a) ==
> > + sizeof(struct {
> > + u16 misc;
> > + u16 afe;
> > + u16 filter;
> > + u16 filter_fs;
> > + u32 offset;
> > + u32 gain;
> > + }));
>
> I think it doesn't make much sense unless one uses memcpy().
memcpy() is used to update the setups after reg write succeeds.
Also, previously, memcmp() was used to compare setups.
Since struct ad4170_setup has only unsigned integers (no floating point fields
like ad7124 had [1]), ad4170 works properly when comparing setups with memcmp().
Though, it was asked to do explicit field matching on previous reviews [2] so
that's how it had been since then. Well, both ways work for ad4170. We can
compare setup with memcmp(), or do the comparison field by field. I don't mind
changing it again if requested. I guess we only need to reach an agreement about
what to go with.
[1]: https://lore.kernel.org/all/20250303114659.1672695-13-u.kleine-koenig@baylibre.com/
[2]: https://lore.kernel.org/linux-iio/20250504192117.5e19f44b@jic23-huawei/
>
> > + if (a->misc != b->misc ||
> > + a->afe != b->afe ||
> > + a->filter != b->filter ||
> > + a->filter_fs != b->filter_fs ||
> > + a->offset != b->offset ||
> > + a->gain != b->gain)
> > + return false;
> > +
> > + return true;
> > +}
>
> ...
>
Thanks,
Marcelo
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [PATCH v4 02/11] iio: adc: Add basic support for AD4170
2025-06-02 16:54 ` Marcelo Schmitt
@ 2025-06-03 8:27 ` Andy Shevchenko
2025-06-03 12:02 ` Marcelo Schmitt
0 siblings, 1 reply; 29+ messages in thread
From: Andy Shevchenko @ 2025-06-03 8:27 UTC (permalink / raw)
To: Marcelo Schmitt
Cc: Marcelo Schmitt, linux-iio, devicetree, linux-gpio, linux-kernel,
Ana-Maria Cusco, jic23, lars, Michael.Hennerich, dlechner,
nuno.sa, robh, krzk+dt, conor+dt, linus.walleij, brgl
On Mon, Jun 02, 2025 at 01:54:25PM -0300, Marcelo Schmitt wrote:
...
> > > +static bool ad4170_setup_eq(struct ad4170_setup *a, struct ad4170_setup *b)
> > > +{
> > > + /*
> > > + * The use of static_assert() here is to make sure that the comparison
> > > + * is adapted whenever struct ad4170_setup is changed.
> > > + */
> > > + static_assert(sizeof(*a) ==
> > > + sizeof(struct {
> > > + u16 misc;
> > > + u16 afe;
> > > + u16 filter;
> > > + u16 filter_fs;
> > > + u32 offset;
> > > + u32 gain;
> > > + }));
> >
> > I think it doesn't make much sense unless one uses memcpy().
>
> memcpy() is used to update the setups after reg write succeeds.
> Also, previously, memcmp() was used to compare setups.
> Since struct ad4170_setup has only unsigned integers (no floating point fields
> like ad7124 had [1]), ad4170 works properly when comparing setups with memcmp().
> Though, it was asked to do explicit field matching on previous reviews [2] so
> that's how it had been since then. Well, both ways work for ad4170. We can
> compare setup with memcmp(), or do the comparison field by field. I don't mind
> changing it again if requested. I guess we only need to reach an agreement about
> what to go with.
The question was "why do you need the static_assert() now?"
> [1]: https://lore.kernel.org/all/20250303114659.1672695-13-u.kleine-koenig@baylibre.com/
> [2]: https://lore.kernel.org/linux-iio/20250504192117.5e19f44b@jic23-huawei/
>
> > > + if (a->misc != b->misc ||
> > > + a->afe != b->afe ||
> > > + a->filter != b->filter ||
> > > + a->filter_fs != b->filter_fs ||
> > > + a->offset != b->offset ||
> > > + a->gain != b->gain)
> > > + return false;
> > > +
> > > + return true;
> > > +}
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [PATCH v4 02/11] iio: adc: Add basic support for AD4170
2025-06-03 8:27 ` Andy Shevchenko
@ 2025-06-03 12:02 ` Marcelo Schmitt
2025-06-03 13:43 ` Andy Shevchenko
0 siblings, 1 reply; 29+ messages in thread
From: Marcelo Schmitt @ 2025-06-03 12:02 UTC (permalink / raw)
To: Andy Shevchenko
Cc: Marcelo Schmitt, linux-iio, devicetree, linux-gpio, linux-kernel,
Ana-Maria Cusco, jic23, lars, Michael.Hennerich, dlechner,
nuno.sa, robh, krzk+dt, conor+dt, linus.walleij, brgl
On 06/03, Andy Shevchenko wrote:
> On Mon, Jun 02, 2025 at 01:54:25PM -0300, Marcelo Schmitt wrote:
>
> ...
>
> > > > +static bool ad4170_setup_eq(struct ad4170_setup *a, struct ad4170_setup *b)
> > > > +{
> > > > + /*
> > > > + * The use of static_assert() here is to make sure that the comparison
> > > > + * is adapted whenever struct ad4170_setup is changed.
> > > > + */
Does the reason given in the comment justify the use of static_assert?
> > > > + static_assert(sizeof(*a) ==
> > > > + sizeof(struct {
> > > > + u16 misc;
> > > > + u16 afe;
> > > > + u16 filter;
> > > > + u16 filter_fs;
> > > > + u32 offset;
> > > > + u32 gain;
> > > > + }));
> > >
> > > I think it doesn't make much sense unless one uses memcpy().
> >
> > memcpy() is used to update the setups after reg write succeeds.
> > Also, previously, memcmp() was used to compare setups.
> > Since struct ad4170_setup has only unsigned integers (no floating point fields
> > like ad7124 had [1]), ad4170 works properly when comparing setups with memcmp().
> > Though, it was asked to do explicit field matching on previous reviews [2] so
> > that's how it had been since then. Well, both ways work for ad4170. We can
> > compare setup with memcmp(), or do the comparison field by field. I don't mind
> > changing it again if requested. I guess we only need to reach an agreement about
> > what to go with.
>
> The question was "why do you need the static_assert() now?"
To ensure that the comparison function gets updated if struct ad4170_setup is
ever modified? This intends to be similar to what was implemented in ad7124
driver as the chips have similar channel configuration mechanisms. We also
have ad7173 and ad4130 using static_assert for analogous purpose. There was
also a comment about static_assert above.
Best regards,
Marcelo
>
> > [1]: https://lore.kernel.org/all/20250303114659.1672695-13-u.kleine-koenig@baylibre.com/
> > [2]: https://lore.kernel.org/linux-iio/20250504192117.5e19f44b@jic23-huawei/
> >
> > > > + if (a->misc != b->misc ||
> > > > + a->afe != b->afe ||
> > > > + a->filter != b->filter ||
> > > > + a->filter_fs != b->filter_fs ||
> > > > + a->offset != b->offset ||
> > > > + a->gain != b->gain)
> > > > + return false;
> > > > +
> > > > + return true;
> > > > +}
>
> --
> With Best Regards,
> Andy Shevchenko
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [PATCH v4 02/11] iio: adc: Add basic support for AD4170
2025-06-03 12:02 ` Marcelo Schmitt
@ 2025-06-03 13:43 ` Andy Shevchenko
2025-06-07 16:59 ` Jonathan Cameron
0 siblings, 1 reply; 29+ messages in thread
From: Andy Shevchenko @ 2025-06-03 13:43 UTC (permalink / raw)
To: Marcelo Schmitt
Cc: Marcelo Schmitt, linux-iio, devicetree, linux-gpio, linux-kernel,
Ana-Maria Cusco, jic23, lars, Michael.Hennerich, dlechner,
nuno.sa, robh, krzk+dt, conor+dt, linus.walleij, brgl
On Tue, Jun 03, 2025 at 09:02:56AM -0300, Marcelo Schmitt wrote:
> On 06/03, Andy Shevchenko wrote:
> > On Mon, Jun 02, 2025 at 01:54:25PM -0300, Marcelo Schmitt wrote:
...
> > > > > +static bool ad4170_setup_eq(struct ad4170_setup *a, struct ad4170_setup *b)
> > > > > +{
> > > > > + /*
> > > > > + * The use of static_assert() here is to make sure that the comparison
> > > > > + * is adapted whenever struct ad4170_setup is changed.
> > > > > + */
> Does the reason given in the comment justify the use of static_assert?
Should I repeat myself? It makes a little sense when no memcmp() is involved.
> > > > > + static_assert(sizeof(*a) ==
> > > > > + sizeof(struct {
> > > > > + u16 misc;
> > > > > + u16 afe;
> > > > > + u16 filter;
> > > > > + u16 filter_fs;
> > > > > + u32 offset;
> > > > > + u32 gain;
> > > > > + }));
> > > >
> > > > I think it doesn't make much sense unless one uses memcpy().
> > >
> > > memcpy() is used to update the setups after reg write succeeds.
> > > Also, previously, memcmp() was used to compare setups.
> > > Since struct ad4170_setup has only unsigned integers (no floating point fields
> > > like ad7124 had [1]), ad4170 works properly when comparing setups with memcmp().
> > > Though, it was asked to do explicit field matching on previous reviews [2] so
> > > that's how it had been since then. Well, both ways work for ad4170. We can
> > > compare setup with memcmp(), or do the comparison field by field. I don't mind
> > > changing it again if requested. I guess we only need to reach an agreement about
> > > what to go with.
> >
> > The question was "why do you need the static_assert() now?"
>
> To ensure that the comparison function gets updated if struct ad4170_setup is
> ever modified? This intends to be similar to what was implemented in ad7124
> driver as the chips have similar channel configuration mechanisms. We also
> have ad7173 and ad4130 using static_assert for analogous purpose. There was
> also a comment about static_assert above.
Does this won;t work if you changes field types? (Assuming only integers to
integers) I believe it doesn't affect the field-by-field comparison.
The other drivers may have different approach, have you studied them? Do they
use memcmp()
> > > [1]: https://lore.kernel.org/all/20250303114659.1672695-13-u.kleine-koenig@baylibre.com/
> > > [2]: https://lore.kernel.org/linux-iio/20250504192117.5e19f44b@jic23-huawei/
> > >
> > > > > + if (a->misc != b->misc ||
> > > > > + a->afe != b->afe ||
> > > > > + a->filter != b->filter ||
> > > > > + a->filter_fs != b->filter_fs ||
> > > > > + a->offset != b->offset ||
> > > > > + a->gain != b->gain)
> > > > > + return false;
> > > > > +
> > > > > + return true;
> > > > > +}
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [PATCH v4 02/11] iio: adc: Add basic support for AD4170
2025-06-03 13:43 ` Andy Shevchenko
@ 2025-06-07 16:59 ` Jonathan Cameron
0 siblings, 0 replies; 29+ messages in thread
From: Jonathan Cameron @ 2025-06-07 16:59 UTC (permalink / raw)
To: Andy Shevchenko
Cc: Marcelo Schmitt, Marcelo Schmitt, linux-iio, devicetree,
linux-gpio, linux-kernel, Ana-Maria Cusco, lars,
Michael.Hennerich, dlechner, nuno.sa, robh, krzk+dt, conor+dt,
linus.walleij, brgl
On Tue, 3 Jun 2025 16:43:42 +0300
Andy Shevchenko <andy@kernel.org> wrote:
> On Tue, Jun 03, 2025 at 09:02:56AM -0300, Marcelo Schmitt wrote:
> > On 06/03, Andy Shevchenko wrote:
> > > On Mon, Jun 02, 2025 at 01:54:25PM -0300, Marcelo Schmitt wrote:
>
> ...
>
> > > > > > +static bool ad4170_setup_eq(struct ad4170_setup *a, struct ad4170_setup *b)
> > > > > > +{
> > > > > > + /*
> > > > > > + * The use of static_assert() here is to make sure that the comparison
> > > > > > + * is adapted whenever struct ad4170_setup is changed.
> > > > > > + */
> > Does the reason given in the comment justify the use of static_assert?
>
> Should I repeat myself? It makes a little sense when no memcmp() is involved.
The intent I think is to reduce the chance of a field being added without
this match function being updated. Not a very strong test but maybe
better than nothing...
Not sure how memcmp() is relevant.
>
> > > > > > + static_assert(sizeof(*a) ==
> > > > > > + sizeof(struct {
> > > > > > + u16 misc;
> > > > > > + u16 afe;
> > > > > > + u16 filter;
> > > > > > + u16 filter_fs;
> > > > > > + u32 offset;
> > > > > > + u32 gain;
> > > > > > + }));
> > > > >
> > > > > I think it doesn't make much sense unless one uses memcpy().
> > > >
> > > > memcpy() is used to update the setups after reg write succeeds.
> > > > Also, previously, memcmp() was used to compare setups.
> > > > Since struct ad4170_setup has only unsigned integers (no floating point fields
> > > > like ad7124 had [1]), ad4170 works properly when comparing setups with memcmp().
> > > > Though, it was asked to do explicit field matching on previous reviews [2] so
> > > > that's how it had been since then. Well, both ways work for ad4170. We can
> > > > compare setup with memcmp(), or do the comparison field by field. I don't mind
> > > > changing it again if requested. I guess we only need to reach an agreement about
> > > > what to go with.
> > >
> > > The question was "why do you need the static_assert() now?"
> >
> > To ensure that the comparison function gets updated if struct ad4170_setup is
> > ever modified? This intends to be similar to what was implemented in ad7124
> > driver as the chips have similar channel configuration mechanisms. We also
> > have ad7173 and ad4130 using static_assert for analogous purpose. There was
> > also a comment about static_assert above.
>
> Does this won;t work if you changes field types? (Assuming only integers to
> integers) I believe it doesn't affect the field-by-field comparison.
>
> The other drivers may have different approach, have you studied them? Do they
> use memcmp()
>
> > > > [1]: https://lore.kernel.org/all/20250303114659.1672695-13-u.kleine-koenig@baylibre.com/
> > > > [2]: https://lore.kernel.org/linux-iio/20250504192117.5e19f44b@jic23-huawei/
> > > >
> > > > > > + if (a->misc != b->misc ||
> > > > > > + a->afe != b->afe ||
> > > > > > + a->filter != b->filter ||
> > > > > > + a->filter_fs != b->filter_fs ||
> > > > > > + a->offset != b->offset ||
> > > > > > + a->gain != b->gain)
> > > > > > + return false;
> > > > > > +
> > > > > > + return true;
> > > > > > +}
>
^ permalink raw reply [flat|nested] 29+ messages in thread
* Re: [PATCH v4 02/11] iio: adc: Add basic support for AD4170
2025-06-02 11:36 ` [PATCH v4 02/11] iio: adc: Add basic support for AD4170 Marcelo Schmitt
2025-06-02 14:55 ` Andy Shevchenko
@ 2025-06-03 14:00 ` kernel test robot
1 sibling, 0 replies; 29+ messages in thread
From: kernel test robot @ 2025-06-03 14:00 UTC (permalink / raw)
To: Marcelo Schmitt, linux-iio, devicetree, linux-gpio, linux-kernel
Cc: oe-kbuild-all, Ana-Maria Cusco, jic23, lars, Michael.Hennerich,
dlechner, nuno.sa, andy, robh, krzk+dt, conor+dt, linus.walleij,
brgl, marcelo.schmitt1
Hi Marcelo,
kernel test robot noticed the following build warnings:
[auto build test WARNING on c06335516e8c14f501a479a4d9de0e6c09c52ef2]
url: https://github.com/intel-lab-lkp/linux/commits/Marcelo-Schmitt/dt-bindings-iio-adc-Add-AD4170/20250603-105744
base: c06335516e8c14f501a479a4d9de0e6c09c52ef2
patch link: https://lore.kernel.org/r/e79f9a126672b33b8a7c01f650fee43a68c74029.1748829860.git.marcelo.schmitt%40analog.com
patch subject: [PATCH v4 02/11] iio: adc: Add basic support for AD4170
config: m68k-allmodconfig (https://download.01.org/0day-ci/archive/20250603/202506032131.wuzW0a3k-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 15.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250603/202506032131.wuzW0a3k-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202506032131.wuzW0a3k-lkp@intel.com/
All warnings (new ones prefixed by >>):
drivers/iio/adc/ad4170.c: In function 'ad4170_parse_reference':
>> drivers/iio/adc/ad4170.c:1130:13: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
1130 | int ret;
| ^~~
vim +/ret +1130 drivers/iio/adc/ad4170.c
1124
1125 static int ad4170_parse_reference(struct ad4170_state *st,
1126 struct fwnode_handle *child,
1127 struct ad4170_setup *setup)
1128 {
1129 struct device *dev = &st->spi->dev;
> 1130 int ret;
1131 u32 aux;
1132
1133 /* Optional positive reference buffering */
1134 aux = AD4170_REF_BUF_FULL; /* Default to full precharge buffer enabled. */
1135 fwnode_property_read_u32(child, "adi,positive-reference-buffer", &aux);
1136 if (aux < AD4170_REF_BUF_PRE || aux > AD4170_REF_BUF_BYPASS)
1137 return dev_err_probe(dev, -EINVAL,
1138 "Invalid adi,positive-reference-buffer: %u\n",
1139 aux);
1140
1141 setup->afe |= FIELD_PREP(AD4170_AFE_REF_BUF_P_MSK, aux);
1142
1143 /* Optional negative reference buffering */
1144 aux = AD4170_REF_BUF_FULL; /* Default to full precharge buffer enabled. */
1145 fwnode_property_read_u32(child, "adi,negative-reference-buffer", &aux);
1146 if (aux < AD4170_REF_BUF_PRE || aux > AD4170_REF_BUF_BYPASS)
1147 return dev_err_probe(dev, -EINVAL,
1148 "Invalid adi,negative-reference-buffer: %u\n",
1149 aux);
1150
1151 setup->afe |= FIELD_PREP(AD4170_AFE_REF_BUF_M_MSK, aux);
1152
1153 /* Optional voltage reference selection */
1154 aux = AD4170_REF_REFOUT; /* Default reference selection. */
1155 ret = fwnode_property_read_u32(child, "adi,reference-select", &aux);
1156 if (aux > AD4170_REF_AVDD)
1157 return dev_err_probe(dev, -EINVAL,
1158 "Invalid reference selected %u\n",
1159 aux);
1160
1161 setup->afe |= FIELD_PREP(AD4170_AFE_REF_SELECT_MSK, aux);
1162
1163 return 0;
1164 }
1165
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 29+ messages in thread
* [PATCH v4 03/11] iio: adc: ad4170: Add support for calibration gain
2025-06-02 11:34 [PATCH v4 00/11] iio: adc: Add support for AD4170 series of ADCs Marcelo Schmitt
2025-06-02 11:36 ` [PATCH v4 01/11] dt-bindings: iio: adc: Add AD4170 Marcelo Schmitt
2025-06-02 11:36 ` [PATCH v4 02/11] iio: adc: Add basic support for AD4170 Marcelo Schmitt
@ 2025-06-02 11:37 ` Marcelo Schmitt
2025-06-02 12:54 ` Andy Shevchenko
2025-06-02 11:37 ` [PATCH v4 04/11] iio: adc: ad4170: Add support for calibration bias Marcelo Schmitt
` (7 subsequent siblings)
10 siblings, 1 reply; 29+ messages in thread
From: Marcelo Schmitt @ 2025-06-02 11:37 UTC (permalink / raw)
To: linux-iio, devicetree, linux-gpio, linux-kernel
Cc: jic23, lars, Michael.Hennerich, dlechner, nuno.sa, andy, robh,
krzk+dt, conor+dt, linus.walleij, brgl, marcelo.schmitt1
Add support for ADC calibration gain configuration.
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
---
Change log v3 -> v4
- No longer restoring calib gain or calib offset on reg write fail.
drivers/iio/adc/ad4170.c | 22 +++++++++++++++++++++-
1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/adc/ad4170.c b/drivers/iio/adc/ad4170.c
index c317529e0449..98e38fabc725 100644
--- a/drivers/iio/adc/ad4170.c
+++ b/drivers/iio/adc/ad4170.c
@@ -631,7 +631,8 @@ static const struct iio_chan_spec ad4170_channel_template = {
.differential = 1,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) |
- BIT(IIO_CHAN_INFO_OFFSET),
+ BIT(IIO_CHAN_INFO_OFFSET) |
+ BIT(IIO_CHAN_INFO_CALIBSCALE),
.info_mask_separate_available = BIT(IIO_CHAN_INFO_SCALE),
.scan_type = {
.realbits = 24,
@@ -945,6 +946,9 @@ static int ad4170_read_raw(struct iio_dev *indio_dev,
pga = FIELD_GET(AD4170_AFE_PGA_GAIN_MSK, setup->afe);
*val = chan_info->offset_tbl[pga];
return IIO_VAL_INT;
+ case IIO_CHAN_INFO_CALIBSCALE:
+ *val = setup->gain;
+ return IIO_VAL_INT;
default:
return -EINVAL;
}
@@ -1059,6 +1063,18 @@ static int ad4170_set_pga(struct ad4170_state *st,
return ad4170_write_channel_setup(st, chan->address, false);
}
+static int ad4170_set_calib_gain(struct ad4170_state *st,
+ struct iio_chan_spec const *chan, int val)
+{
+ struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
+ struct ad4170_setup *setup = &chan_info->setup;
+
+ guard(mutex)(&st->lock);
+ setup->gain = val;
+
+ return ad4170_write_channel_setup(st, chan->address, false);
+}
+
static int __ad4170_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int val,
int val2, long info)
@@ -1068,6 +1084,8 @@ static int __ad4170_write_raw(struct iio_dev *indio_dev,
switch (info) {
case IIO_CHAN_INFO_SCALE:
return ad4170_set_pga(st, chan, val, val2);
+ case IIO_CHAN_INFO_CALIBSCALE:
+ return ad4170_set_calib_gain(st, chan, val);
default:
return -EINVAL;
}
@@ -1094,6 +1112,8 @@ static int ad4170_write_raw_get_fmt(struct iio_dev *indio_dev,
switch (info) {
case IIO_CHAN_INFO_SCALE:
return IIO_VAL_INT_PLUS_NANO;
+ case IIO_CHAN_INFO_CALIBSCALE:
+ return IIO_VAL_INT;
default:
return -EINVAL;
}
--
2.47.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* Re: [PATCH v4 03/11] iio: adc: ad4170: Add support for calibration gain
2025-06-02 11:37 ` [PATCH v4 03/11] iio: adc: ad4170: Add support for calibration gain Marcelo Schmitt
@ 2025-06-02 12:54 ` Andy Shevchenko
0 siblings, 0 replies; 29+ messages in thread
From: Andy Shevchenko @ 2025-06-02 12:54 UTC (permalink / raw)
To: Marcelo Schmitt
Cc: linux-iio, devicetree, linux-gpio, linux-kernel, jic23, lars,
Michael.Hennerich, dlechner, nuno.sa, robh, krzk+dt, conor+dt,
linus.walleij, brgl, marcelo.schmitt1
On Mon, Jun 02, 2025 at 08:37:11AM -0300, Marcelo Schmitt wrote:
> Add support for ADC calibration gain configuration.
...
> .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> BIT(IIO_CHAN_INFO_SCALE) |
> - BIT(IIO_CHAN_INFO_OFFSET),
> + BIT(IIO_CHAN_INFO_OFFSET) |
> + BIT(IIO_CHAN_INFO_CALIBSCALE),
If you squeeze the added bit in between the upper lines, the diff will be much
clearer.
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 29+ messages in thread
* [PATCH v4 04/11] iio: adc: ad4170: Add support for calibration bias
2025-06-02 11:34 [PATCH v4 00/11] iio: adc: Add support for AD4170 series of ADCs Marcelo Schmitt
` (2 preceding siblings ...)
2025-06-02 11:37 ` [PATCH v4 03/11] iio: adc: ad4170: Add support for calibration gain Marcelo Schmitt
@ 2025-06-02 11:37 ` Marcelo Schmitt
2025-06-02 11:38 ` [PATCH v4 05/11] iio: adc: ad4170: Add digital filter and sample frequency config support Marcelo Schmitt
` (6 subsequent siblings)
10 siblings, 0 replies; 29+ messages in thread
From: Marcelo Schmitt @ 2025-06-02 11:37 UTC (permalink / raw)
To: linux-iio, devicetree, linux-gpio, linux-kernel
Cc: jic23, lars, Michael.Hennerich, dlechner, nuno.sa, andy, robh,
krzk+dt, conor+dt, linus.walleij, brgl, marcelo.schmitt1
Add support for ADC calibration bias/offset configuration.
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
---
Change log v3 -> v4
- No longer restoring calib gain or calib offset on reg write fail.
drivers/iio/adc/ad4170.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/drivers/iio/adc/ad4170.c b/drivers/iio/adc/ad4170.c
index 98e38fabc725..b109ebf3347d 100644
--- a/drivers/iio/adc/ad4170.c
+++ b/drivers/iio/adc/ad4170.c
@@ -632,6 +632,7 @@ static const struct iio_chan_spec ad4170_channel_template = {
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_OFFSET) |
+ BIT(IIO_CHAN_INFO_CALIBBIAS) |
BIT(IIO_CHAN_INFO_CALIBSCALE),
.info_mask_separate_available = BIT(IIO_CHAN_INFO_SCALE),
.scan_type = {
@@ -946,6 +947,9 @@ static int ad4170_read_raw(struct iio_dev *indio_dev,
pga = FIELD_GET(AD4170_AFE_PGA_GAIN_MSK, setup->afe);
*val = chan_info->offset_tbl[pga];
return IIO_VAL_INT;
+ case IIO_CHAN_INFO_CALIBBIAS:
+ *val = setup->offset;
+ return IIO_VAL_INT;
case IIO_CHAN_INFO_CALIBSCALE:
*val = setup->gain;
return IIO_VAL_INT;
@@ -1063,6 +1067,18 @@ static int ad4170_set_pga(struct ad4170_state *st,
return ad4170_write_channel_setup(st, chan->address, false);
}
+static int ad4170_set_calib_offset(struct ad4170_state *st,
+ struct iio_chan_spec const *chan, int val)
+{
+ struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
+ struct ad4170_setup *setup = &chan_info->setup;
+
+ guard(mutex)(&st->lock);
+ setup->offset = val;
+
+ return ad4170_write_channel_setup(st, chan->address, false);
+}
+
static int ad4170_set_calib_gain(struct ad4170_state *st,
struct iio_chan_spec const *chan, int val)
{
@@ -1084,6 +1100,8 @@ static int __ad4170_write_raw(struct iio_dev *indio_dev,
switch (info) {
case IIO_CHAN_INFO_SCALE:
return ad4170_set_pga(st, chan, val, val2);
+ case IIO_CHAN_INFO_CALIBBIAS:
+ return ad4170_set_calib_offset(st, chan, val);
case IIO_CHAN_INFO_CALIBSCALE:
return ad4170_set_calib_gain(st, chan, val);
default:
@@ -1112,6 +1130,7 @@ static int ad4170_write_raw_get_fmt(struct iio_dev *indio_dev,
switch (info) {
case IIO_CHAN_INFO_SCALE:
return IIO_VAL_INT_PLUS_NANO;
+ case IIO_CHAN_INFO_CALIBBIAS:
case IIO_CHAN_INFO_CALIBSCALE:
return IIO_VAL_INT;
default:
--
2.47.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v4 05/11] iio: adc: ad4170: Add digital filter and sample frequency config support
2025-06-02 11:34 [PATCH v4 00/11] iio: adc: Add support for AD4170 series of ADCs Marcelo Schmitt
` (3 preceding siblings ...)
2025-06-02 11:37 ` [PATCH v4 04/11] iio: adc: ad4170: Add support for calibration bias Marcelo Schmitt
@ 2025-06-02 11:38 ` Marcelo Schmitt
2025-06-02 11:38 ` [PATCH v4 06/11] iio: adc: ad4170: Add support for buffered data capture Marcelo Schmitt
` (5 subsequent siblings)
10 siblings, 0 replies; 29+ messages in thread
From: Marcelo Schmitt @ 2025-06-02 11:38 UTC (permalink / raw)
To: linux-iio, devicetree, linux-gpio, linux-kernel
Cc: jic23, lars, Michael.Hennerich, dlechner, nuno.sa, andy, robh,
krzk+dt, conor+dt, linus.walleij, brgl, marcelo.schmitt1
Add support for sinc3, sinc5, and averaged sinc5 digital filters along with
sample frequency configuration.
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
---
Change log v3 -> v4
- Use scoped_guard to ensure correct lock release order in ad4170_set_filter_type().
drivers/iio/adc/ad4170.c | 262 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 259 insertions(+), 3 deletions(-)
diff --git a/drivers/iio/adc/ad4170.c b/drivers/iio/adc/ad4170.c
index b109ebf3347d..3d83c3ace569 100644
--- a/drivers/iio/adc/ad4170.c
+++ b/drivers/iio/adc/ad4170.c
@@ -17,6 +17,7 @@
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/math64.h>
+#include <linux/minmax.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/regmap.h>
@@ -85,6 +86,9 @@
#define AD4170_AFE_BIPOLAR_MSK BIT(4)
#define AD4170_AFE_PGA_GAIN_MSK GENMASK(3, 0)
+/* AD4170_FILTER_REG */
+#define AD4170_FILTER_FILTER_TYPE_MSK GENMASK(3, 0)
+
/* AD4170 register constants */
/* AD4170_CHAN_MAP_REG constants */
@@ -110,6 +114,11 @@
#define AD4170_ADC_CTRL_MODE_SINGLE 0x4
#define AD4170_ADC_CTRL_MODE_IDLE 0x7
+/* AD4170_FILTER_REG constants */
+#define AD4170_FILTER_FILTER_TYPE_SINC5_AVG 0x0
+#define AD4170_FILTER_FILTER_TYPE_SINC5 0x4
+#define AD4170_FILTER_FILTER_TYPE_SINC3 0x6
+
/* Device properties and auxiliary constants */
#define AD4170_NUM_ANALOG_PINS 9
@@ -118,6 +127,7 @@
#define AD4170_MAX_SETUPS 8
#define AD4170_INVALID_SETUP 9
#define AD4170_SPI_MAX_XFER_LEN 6
+#define AD4170_DEFAULT_SAMP_RATE (125 * HZ_PER_KHZ)
#define AD4170_INT_REF_2_5V 2500000
@@ -126,6 +136,12 @@
#define AD4170_NUM_PGA_OPTIONS 10
+/* Digital filter properties */
+#define AD4170_SINC3_MIN_FS 4
+#define AD4170_SINC3_MAX_FS 65532
+#define AD4170_SINC5_MIN_FS 1
+#define AD4170_SINC5_MAX_FS 256
+
#define AD4170_GAIN_REG_DEFAULT 0x555555
static const unsigned int ad4170_reg_size[] = {
@@ -179,6 +195,12 @@ enum ad4170_ref_select {
AD4170_REF_AVDD
};
+enum ad4170_filter_type {
+ AD4170_SINC5_AVG,
+ AD4170_SINC5,
+ AD4170_SINC3,
+};
+
enum ad4170_regulator {
AD4170_AVDD_SUP,
AD4170_AVSS_SUP,
@@ -200,6 +222,18 @@ static const char * const ad4170_int_pin_names[] = {
[AD4170_INT_PIN_DIG_AUX1] = "dig_aux1",
};
+static const unsigned int ad4170_sinc3_filt_fs_tbl[] = {
+ 4, 8, 12, 16, 20, 40, 48, 80, /* 0 - 7 */
+ 100, 256, 500, 1000, 5000, 8332, 10000, 25000, /* 8 - 15 */
+ 50000, 65532, /* 16 - 17 */
+};
+
+#define AD4170_MAX_FS_TBL_SIZE ARRAY_SIZE(ad4170_sinc3_filt_fs_tbl)
+
+static const unsigned int ad4170_sinc5_filt_fs_tbl[] = {
+ 1, 2, 4, 8, 12, 16, 20, 40, 48, 80, 100, 256,
+};
+
struct ad4170_chip_info {
const char *name;
};
@@ -257,6 +291,12 @@ struct ad4170_chan_info {
bool enabled;
};
+static const char * const ad4170_filt_names[] = {
+ [AD4170_SINC5_AVG] = "sinc5+avg",
+ [AD4170_SINC5] = "sinc5",
+ [AD4170_SINC3] = "sinc3",
+};
+
struct ad4170_state {
struct mutex lock; /* Protect read-modify-write and multi write sequences */
int vrefs_uv[AD4170_MAX_SUP];
@@ -266,6 +306,7 @@ struct ad4170_state {
struct ad4170_chan_info chan_infos[AD4170_MAX_CHANNELS];
struct spi_device *spi;
struct regmap *regmap;
+ int sps_tbl[ARRAY_SIZE(ad4170_filt_names)][AD4170_MAX_FS_TBL_SIZE][2];
struct completion completion;
int pins_fn[AD4170_NUM_ANALOG_PINS];
u32 int_pin_sel;
@@ -277,6 +318,38 @@ struct ad4170_state {
u8 rx_buf[4];
};
+static void ad4170_fill_sps_tbl(struct ad4170_state *st)
+{
+ unsigned int tmp0, tmp1, i;
+
+ /*
+ * The ODR can be calculated the same way for sinc5+avg, sinc5, and
+ * sinc3 filter types with the exception that sinc5 filter has a
+ * narrowed range of allowed FILTER_FS values.
+ */
+ for (i = 0; i < ARRAY_SIZE(ad4170_sinc3_filt_fs_tbl); i++) {
+ tmp0 = div_u64_rem(st->mclk_hz, 32 * ad4170_sinc3_filt_fs_tbl[i],
+ &tmp1);
+ tmp1 = mult_frac(tmp1, MICRO, 32 * ad4170_sinc3_filt_fs_tbl[i]);
+ /* Fill sinc5+avg filter SPS table */
+ st->sps_tbl[AD4170_SINC5_AVG][i][0] = tmp0; /* Integer part */
+ st->sps_tbl[AD4170_SINC5_AVG][i][1] = tmp1; /* Fractional part */
+
+ /* Fill sinc3 filter SPS table */
+ st->sps_tbl[AD4170_SINC3][i][0] = tmp0; /* Integer part */
+ st->sps_tbl[AD4170_SINC3][i][1] = tmp1; /* Fractional part */
+ }
+ /* Sinc5 filter ODR doesn't use all FILTER_FS bits */
+ for (i = 0; i < ARRAY_SIZE(ad4170_sinc5_filt_fs_tbl); i++) {
+ tmp0 = div_u64_rem(st->mclk_hz, 32 * ad4170_sinc5_filt_fs_tbl[i],
+ &tmp1);
+ tmp1 = mult_frac(tmp1, MICRO, 32 * ad4170_sinc5_filt_fs_tbl[i]);
+ /* Fill sinc5 filter SPS table */
+ st->sps_tbl[AD4170_SINC5][i][0] = tmp0; /* Integer part */
+ st->sps_tbl[AD4170_SINC5][i][1] = tmp1; /* Fractional part */
+ }
+}
+
static int ad4170_debugfs_reg_access(struct iio_dev *indio_dev,
unsigned int reg, unsigned int writeval,
unsigned int *readval)
@@ -625,6 +698,100 @@ static int ad4170_set_channel_enable(struct ad4170_state *st,
return 0;
}
+static int __ad4170_get_filter_type(unsigned int filter)
+{
+ u16 f_conf = FIELD_GET(AD4170_FILTER_FILTER_TYPE_MSK, filter);
+
+ switch (f_conf) {
+ case AD4170_FILTER_FILTER_TYPE_SINC5_AVG:
+ return AD4170_SINC5_AVG;
+ case AD4170_FILTER_FILTER_TYPE_SINC5:
+ return AD4170_SINC5;
+ case AD4170_FILTER_FILTER_TYPE_SINC3:
+ return AD4170_SINC3;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad4170_set_filter_type(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ unsigned int val)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
+ struct ad4170_setup *setup = &chan_info->setup;
+ unsigned int filter_type_conf;
+ int ret;
+
+ switch (val) {
+ case AD4170_SINC5_AVG:
+ filter_type_conf = AD4170_FILTER_FILTER_TYPE_SINC5_AVG;
+ break;
+ case AD4170_SINC5:
+ filter_type_conf = AD4170_FILTER_FILTER_TYPE_SINC5;
+ break;
+ case AD4170_SINC3:
+ filter_type_conf = AD4170_FILTER_FILTER_TYPE_SINC3;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /*
+ * The filters provide the same ODR for a given filter_fs value but
+ * there are different minimum and maximum filter_fs limits for each
+ * filter. The filter_fs value will be adjusted if the current filter_fs
+ * is out of the limits of the just requested filter. Since the
+ * filter_fs value affects the ODR (sampling_frequency), changing the
+ * filter may lead to a change in the sampling frequency.
+ */
+ scoped_guard(mutex, &st->lock) {
+ if (!iio_device_claim_direct(indio_dev))
+ return -EBUSY;
+
+ if (val == AD4170_SINC5_AVG || val == AD4170_SINC3)
+ setup->filter_fs = clamp(val, AD4170_SINC3_MIN_FS,
+ AD4170_SINC3_MAX_FS);
+ else
+ setup->filter_fs = clamp(val, AD4170_SINC5_MIN_FS,
+ AD4170_SINC5_MAX_FS);
+
+ setup->filter &= ~AD4170_FILTER_FILTER_TYPE_MSK;
+ setup->filter |= FIELD_PREP(AD4170_FILTER_FILTER_TYPE_MSK,
+ filter_type_conf);
+
+ ret = ad4170_write_channel_setup(st, chan->address, false);
+ iio_device_release_direct(indio_dev);
+ }
+
+ return ret;
+}
+
+static int ad4170_get_filter_type(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
+ struct ad4170_setup *setup = &chan_info->setup;
+
+ return __ad4170_get_filter_type(setup->filter);
+}
+
+static const struct iio_enum ad4170_filter_type_enum = {
+ .items = ad4170_filt_names,
+ .num_items = ARRAY_SIZE(ad4170_filt_names),
+ .get = ad4170_get_filter_type,
+ .set = ad4170_set_filter_type,
+};
+
+static const struct iio_chan_spec_ext_info ad4170_filter_type_ext_info[] = {
+ IIO_ENUM("filter_type", IIO_SEPARATE, &ad4170_filter_type_enum),
+ IIO_ENUM_AVAILABLE("filter_type", IIO_SHARED_BY_TYPE,
+ &ad4170_filter_type_enum),
+ { }
+};
+
static const struct iio_chan_spec ad4170_channel_template = {
.type = IIO_VOLTAGE,
.indexed = 1,
@@ -633,8 +800,11 @@ static const struct iio_chan_spec ad4170_channel_template = {
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_OFFSET) |
BIT(IIO_CHAN_INFO_CALIBBIAS) |
- BIT(IIO_CHAN_INFO_CALIBSCALE),
- .info_mask_separate_available = BIT(IIO_CHAN_INFO_SCALE),
+ BIT(IIO_CHAN_INFO_CALIBSCALE) |
+ BIT(IIO_CHAN_INFO_SAMP_FREQ),
+ .info_mask_separate_available = BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_SAMP_FREQ),
+ .ext_info = ad4170_filter_type_ext_info,
.scan_type = {
.realbits = 24,
.storagebits = 32,
@@ -926,7 +1096,8 @@ static int ad4170_read_raw(struct iio_dev *indio_dev,
struct ad4170_state *st = iio_priv(indio_dev);
struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
struct ad4170_setup *setup = &chan_info->setup;
- unsigned int pga;
+ enum ad4170_filter_type f_type;
+ unsigned int pga, fs_idx;
int ret;
guard(mutex)(&st->lock);
@@ -947,6 +1118,27 @@ static int ad4170_read_raw(struct iio_dev *indio_dev,
pga = FIELD_GET(AD4170_AFE_PGA_GAIN_MSK, setup->afe);
*val = chan_info->offset_tbl[pga];
return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ f_type = __ad4170_get_filter_type(setup->filter);
+ switch (f_type) {
+ case AD4170_SINC5_AVG:
+ case AD4170_SINC3:
+ fs_idx = find_closest(setup->filter_fs,
+ ad4170_sinc3_filt_fs_tbl,
+ ARRAY_SIZE(ad4170_sinc3_filt_fs_tbl));
+ *val = st->sps_tbl[f_type][fs_idx][0];
+ *val2 = st->sps_tbl[f_type][fs_idx][1];
+ return IIO_VAL_INT_PLUS_MICRO;
+ case AD4170_SINC5:
+ fs_idx = find_closest(setup->filter_fs,
+ ad4170_sinc5_filt_fs_tbl,
+ ARRAY_SIZE(ad4170_sinc5_filt_fs_tbl));
+ *val = st->sps_tbl[f_type][fs_idx][0];
+ *val2 = st->sps_tbl[f_type][fs_idx][1];
+ return IIO_VAL_INT_PLUS_MICRO;
+ default:
+ return -EINVAL;
+ }
case IIO_CHAN_INFO_CALIBBIAS:
*val = setup->offset;
return IIO_VAL_INT;
@@ -1032,6 +1224,7 @@ static int ad4170_read_avail(struct iio_dev *indio_dev,
{
struct ad4170_state *st = iio_priv(indio_dev);
struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
+ enum ad4170_filter_type f_type;
switch (info) {
case IIO_CHAN_INFO_SCALE:
@@ -1039,6 +1232,21 @@ static int ad4170_read_avail(struct iio_dev *indio_dev,
*length = ARRAY_SIZE(chan_info->scale_tbl) * 2;
*type = IIO_VAL_INT_PLUS_NANO;
return IIO_AVAIL_LIST;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ f_type = ad4170_get_filter_type(indio_dev, chan);
+ *vals = (int *)st->sps_tbl[f_type];
+ *type = IIO_VAL_INT_PLUS_MICRO;
+ switch (f_type) {
+ case AD4170_SINC5_AVG:
+ case AD4170_SINC3:
+ *length = ARRAY_SIZE(ad4170_sinc3_filt_fs_tbl) * 2;
+ return IIO_AVAIL_LIST;
+ case AD4170_SINC5:
+ *length = ARRAY_SIZE(ad4170_sinc5_filt_fs_tbl) * 2;
+ return IIO_AVAIL_LIST;
+ default:
+ return -EINVAL;
+ }
default:
return -EINVAL;
}
@@ -1067,6 +1275,42 @@ static int ad4170_set_pga(struct ad4170_state *st,
return ad4170_write_channel_setup(st, chan->address, false);
}
+static int ad4170_set_channel_freq(struct ad4170_state *st,
+ struct iio_chan_spec const *chan, int val,
+ int val2)
+{
+ struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
+ struct ad4170_setup *setup = &chan_info->setup;
+ enum ad4170_filter_type f_type = __ad4170_get_filter_type(setup->filter);
+ unsigned int filt_fs_tbl_size, i;
+
+ switch (f_type) {
+ case AD4170_SINC5_AVG:
+ case AD4170_SINC3:
+ filt_fs_tbl_size = ARRAY_SIZE(ad4170_sinc3_filt_fs_tbl);
+ break;
+ case AD4170_SINC5:
+ filt_fs_tbl_size = ARRAY_SIZE(ad4170_sinc5_filt_fs_tbl);
+ break;
+ }
+
+ for (i = 0; i < filt_fs_tbl_size; i++) {
+ if (st->sps_tbl[f_type][i][0] == val &&
+ st->sps_tbl[f_type][i][1] == val2)
+ break;
+ }
+ if (i == filt_fs_tbl_size)
+ return -EINVAL;
+
+ guard(mutex)(&st->lock);
+ if (f_type == AD4170_SINC5)
+ setup->filter_fs = ad4170_sinc5_filt_fs_tbl[i];
+ else
+ setup->filter_fs = ad4170_sinc3_filt_fs_tbl[i];
+
+ return ad4170_write_channel_setup(st, chan->address, false);
+}
+
static int ad4170_set_calib_offset(struct ad4170_state *st,
struct iio_chan_spec const *chan, int val)
{
@@ -1100,6 +1344,8 @@ static int __ad4170_write_raw(struct iio_dev *indio_dev,
switch (info) {
case IIO_CHAN_INFO_SCALE:
return ad4170_set_pga(st, chan, val, val2);
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ return ad4170_set_channel_freq(st, chan, val, val2);
case IIO_CHAN_INFO_CALIBBIAS:
return ad4170_set_calib_offset(st, chan, val);
case IIO_CHAN_INFO_CALIBSCALE:
@@ -1130,6 +1376,8 @@ static int ad4170_write_raw_get_fmt(struct iio_dev *indio_dev,
switch (info) {
case IIO_CHAN_INFO_SCALE:
return IIO_VAL_INT_PLUS_NANO;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_CALIBBIAS:
case IIO_CHAN_INFO_CALIBSCALE:
return IIO_VAL_INT;
@@ -1360,6 +1608,8 @@ static int ad4170_initial_config(struct iio_dev *indio_dev)
unsigned int i;
int ret;
+ ad4170_fill_sps_tbl(st);
+
ret = regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG,
AD4170_ADC_CTRL_MODE_MSK,
FIELD_PREP(AD4170_ADC_CTRL_MODE_MSK,
@@ -1392,6 +1642,12 @@ static int ad4170_initial_config(struct iio_dev *indio_dev)
return dev_err_probe(dev, ret,
"Failed to write CHAN_MAP_REG\n");
+ ret = ad4170_set_channel_freq(st, chan,
+ AD4170_DEFAULT_SAMP_RATE, 0);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to set channel freq\n");
+
ret = ad4170_fill_scale_tbl(indio_dev, chan);
if (ret)
return dev_err_probe(dev, ret,
--
2.47.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v4 06/11] iio: adc: ad4170: Add support for buffered data capture
2025-06-02 11:34 [PATCH v4 00/11] iio: adc: Add support for AD4170 series of ADCs Marcelo Schmitt
` (4 preceding siblings ...)
2025-06-02 11:38 ` [PATCH v4 05/11] iio: adc: ad4170: Add digital filter and sample frequency config support Marcelo Schmitt
@ 2025-06-02 11:38 ` Marcelo Schmitt
2025-06-07 17:06 ` Jonathan Cameron
2025-06-02 11:39 ` [PATCH v4 07/11] iio: adc: ad4170: Add clock provider support Marcelo Schmitt
` (4 subsequent siblings)
10 siblings, 1 reply; 29+ messages in thread
From: Marcelo Schmitt @ 2025-06-02 11:38 UTC (permalink / raw)
To: linux-iio, devicetree, linux-gpio, linux-kernel
Cc: jic23, lars, Michael.Hennerich, dlechner, nuno.sa, andy, robh,
krzk+dt, conor+dt, linus.walleij, brgl, marcelo.schmitt1
Extend the AD4170 driver to allow buffered data capture in continuous read
mode. In continuous read mode, the chip skips the instruction phase and
outputs just ADC sample data, enabling faster sample rates to be reached.
The internal channel sequencer always starts sampling from channel 0 and
channel 0 must be enabled if more than one channel is selected for data
capture. The scan mask validation callback checks if the aforementioned
condition is met.
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
---
Change log v3 -> v4
- Fixed a bug in the filling of the IIO device buffer.
drivers/iio/adc/Kconfig | 2 +
drivers/iio/adc/ad4170.c | 215 ++++++++++++++++++++++++++++++++++++++-
2 files changed, 216 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 03966d07a721..b12dcc04c894 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -89,6 +89,8 @@ config AD4170
tristate "Analog Device AD4170 ADC Driver"
depends on SPI
select REGMAP_SPI
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
help
Say yes here to build support for Analog Devices AD4170 SPI analog
to digital converters (ADC).
diff --git a/drivers/iio/adc/ad4170.c b/drivers/iio/adc/ad4170.c
index 3d83c3ace569..86ef70acbf21 100644
--- a/drivers/iio/adc/ad4170.c
+++ b/drivers/iio/adc/ad4170.c
@@ -13,7 +13,11 @@
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
+#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/math64.h>
@@ -56,6 +60,7 @@
#define AD4170_FILTER_FS_REG(x) (0xC7 + 14 * (x))
#define AD4170_OFFSET_REG(x) (0xCA + 14 * (x))
#define AD4170_GAIN_REG(x) (0xCD + 14 * (x))
+#define AD4170_ADC_CTRL_CONT_READ_EXIT_REG 0x200 /* virtual reg */
#define AD4170_REG_READ_MASK BIT(14)
@@ -67,6 +72,7 @@
/* AD4170_ADC_CTRL_REG */
#define AD4170_ADC_CTRL_MULTI_DATA_REG_SEL_MSK BIT(7)
+#define AD4170_ADC_CTRL_CONT_READ_MSK GENMASK(5, 4)
#define AD4170_ADC_CTRL_MODE_MSK GENMASK(3, 0)
/* AD4170_CHAN_EN_REG */
@@ -111,9 +117,13 @@
#define AD4170_PIN_MUXING_DIG_AUX1_RDY 0x1
/* AD4170_ADC_CTRL_REG constants */
+#define AD4170_ADC_CTRL_MODE_CONT 0x0
#define AD4170_ADC_CTRL_MODE_SINGLE 0x4
#define AD4170_ADC_CTRL_MODE_IDLE 0x7
+#define AD4170_ADC_CTRL_CONT_READ_DISABLE 0x0
+#define AD4170_ADC_CTRL_CONT_READ_ENABLE 0x1
+
/* AD4170_FILTER_REG constants */
#define AD4170_FILTER_FILTER_TYPE_SINC5_AVG 0x0
#define AD4170_FILTER_FILTER_TYPE_SINC5 0x4
@@ -144,6 +154,8 @@
#define AD4170_GAIN_REG_DEFAULT 0x555555
+#define AD4170_ADC_CTRL_CONT_READ_EXIT 0xA5
+
static const unsigned int ad4170_reg_size[] = {
[AD4170_CONFIG_A_REG] = 1,
[AD4170_DATA_24B_REG] = 3,
@@ -180,6 +192,7 @@ static const unsigned int ad4170_reg_size[] = {
[AD4170_OFFSET_REG(5) ... AD4170_GAIN_REG(5)] = 3,
[AD4170_OFFSET_REG(6) ... AD4170_GAIN_REG(6)] = 3,
[AD4170_OFFSET_REG(7) ... AD4170_GAIN_REG(7)] = 3,
+ [AD4170_ADC_CTRL_CONT_READ_EXIT_REG] = 0,
};
enum ad4170_ref_buf {
@@ -307,6 +320,10 @@ struct ad4170_state {
struct spi_device *spi;
struct regmap *regmap;
int sps_tbl[ARRAY_SIZE(ad4170_filt_names)][AD4170_MAX_FS_TBL_SIZE][2];
+ __be32 bounce_buffer[AD4170_MAX_CHANNELS];
+ struct spi_message msg;
+ struct spi_transfer xfer;
+ struct iio_trigger *trig;
struct completion completion;
int pins_fn[AD4170_NUM_ANALOG_PINS];
u32 int_pin_sel;
@@ -394,6 +411,10 @@ static int ad4170_reg_write(void *context, unsigned int reg, unsigned int val)
case 1:
st->tx_buf[2] = val;
break;
+ case 0:
+ /* Write continuous read exit code */
+ st->tx_buf[0] = AD4170_ADC_CTRL_CONT_READ_EXIT;
+ return spi_write(st->spi, st->tx_buf, 1);
default:
return -EINVAL;
}
@@ -808,6 +829,7 @@ static const struct iio_chan_spec ad4170_channel_template = {
.scan_type = {
.realbits = 24,
.storagebits = 32,
+ .shift = 8,
.endianness = IIO_BE,
},
};
@@ -1386,11 +1408,27 @@ static int ad4170_write_raw_get_fmt(struct iio_dev *indio_dev,
}
}
+static int ad4170_update_scan_mode(struct iio_dev *indio_dev,
+ const unsigned long *active_scan_mask)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ unsigned int chan_index;
+ int ret;
+
+ iio_for_each_active_channel(indio_dev, chan_index) {
+ ret = ad4170_set_channel_enable(st, chan_index, true);
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
static const struct iio_info ad4170_info = {
.read_raw = ad4170_read_raw,
.read_avail = ad4170_read_avail,
.write_raw = ad4170_write_raw,
.write_raw_get_fmt = ad4170_write_raw_get_fmt,
+ .update_scan_mode = ad4170_update_scan_mode,
.debugfs_reg_access = ad4170_debugfs_reg_access,
};
@@ -1670,16 +1708,177 @@ static int ad4170_initial_config(struct iio_dev *indio_dev)
AD4170_ADC_CTRL_MULTI_DATA_REG_SEL_MSK);
}
+static int ad4170_prepare_spi_message(struct ad4170_state *st)
+{
+ /*
+ * Continuous data register read is enabled on buffer postenable so
+ * no instruction phase is needed meaning we don't need to send the
+ * register address to read data. Transfer only needs the read buffer.
+ */
+ st->xfer.rx_buf = &st->rx_buf;
+ st->xfer.len = BITS_TO_BYTES(ad4170_channel_template.scan_type.realbits);
+
+ spi_message_init_with_transfers(&st->msg, &st->xfer, 1);
+
+ return devm_spi_optimize_message(&st->spi->dev, st->spi, &st->msg);
+}
+
+static int ad4170_buffer_postenable(struct iio_dev *indio_dev)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ int ret;
+
+ ret = regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG,
+ AD4170_ADC_CTRL_MODE_MSK,
+ FIELD_PREP(AD4170_ADC_CTRL_MODE_MSK,
+ AD4170_ADC_CTRL_MODE_CONT));
+ if (ret)
+ return ret;
+
+ /*
+ * This enables continuous read of the ADC data register. The ADC must
+ * be in continuous conversion mode.
+ */
+ return regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG,
+ AD4170_ADC_CTRL_CONT_READ_MSK,
+ FIELD_PREP(AD4170_ADC_CTRL_CONT_READ_MSK,
+ AD4170_ADC_CTRL_CONT_READ_ENABLE));
+}
+
+static int ad4170_buffer_predisable(struct iio_dev *indio_dev)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ unsigned int i;
+ int ret;
+
+ /*
+ * Use a high register address (virtual register) to request a write of
+ * 0xA5 to the ADC during the first 8 SCLKs of the ADC data read cycle,
+ * thus exiting continuous read.
+ */
+ ret = regmap_write(st->regmap, AD4170_ADC_CTRL_CONT_READ_EXIT_REG, 0);
+ if (ret)
+ return ret;
+
+ ret = regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG,
+ AD4170_ADC_CTRL_CONT_READ_MSK,
+ FIELD_PREP(AD4170_ADC_CTRL_CONT_READ_MSK,
+ AD4170_ADC_CTRL_CONT_READ_DISABLE));
+ if (ret)
+ return ret;
+
+ ret = regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG,
+ AD4170_ADC_CTRL_MODE_MSK,
+ FIELD_PREP(AD4170_ADC_CTRL_MODE_MSK,
+ AD4170_ADC_CTRL_MODE_IDLE));
+ if (ret)
+ return ret;
+
+ /*
+ * The ADC sequences through all the enabled channels (see datasheet
+ * page 95). That can lead to incorrect channel being read if a
+ * single-shot read (or buffered read with different active_scan_mask)
+ * is done after buffer disable. Disable all channels so only requested
+ * channels will be read.
+ */
+ for (i = 0; i < indio_dev->num_channels; i++) {
+ ret = ad4170_set_channel_enable(st, i, false);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static bool ad4170_validate_scan_mask(struct iio_dev *indio_dev,
+ const unsigned long *scan_mask)
+{
+ unsigned int masklength = iio_get_masklength(indio_dev);
+
+ /*
+ * The channel sequencer cycles through the enabled channels in
+ * sequential order, from channel 0 to channel 15, bypassing disabled
+ * channels. When more than one channel is enabled, channel 0 must
+ * always be enabled. See datasheet channel_en register description at
+ * page 95.
+ */
+ if (bitmap_weight(scan_mask, masklength) > 1)
+ return test_bit(0, scan_mask);
+
+ return bitmap_weight(scan_mask, masklength) == 1;
+}
+
+static const struct iio_buffer_setup_ops ad4170_buffer_ops = {
+ .postenable = ad4170_buffer_postenable,
+ .predisable = ad4170_buffer_predisable,
+ .validate_scan_mask = ad4170_validate_scan_mask,
+};
+
+static irqreturn_t ad4170_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct ad4170_state *st = iio_priv(indio_dev);
+ unsigned int chan_index;
+ unsigned int i = 0;
+ int ret;
+
+ iio_for_each_active_channel(indio_dev, chan_index) {
+ ret = spi_sync(st->spi, &st->msg);
+ if (ret)
+ goto err_out;
+
+ memcpy(&st->bounce_buffer[i++], st->rx_buf, ARRAY_SIZE(st->rx_buf));
+ }
+
+ iio_push_to_buffers(indio_dev, st->bounce_buffer);
+err_out:
+ iio_trigger_notify_done(indio_dev->trig);
+ return IRQ_HANDLED;
+}
+
+static const struct iio_trigger_ops ad4170_trigger_ops = {
+ .validate_device = iio_trigger_validate_own_device,
+};
+
static irqreturn_t ad4170_irq_handler(int irq, void *dev_id)
{
struct iio_dev *indio_dev = dev_id;
struct ad4170_state *st = iio_priv(indio_dev);
- complete(&st->completion);
+ if (iio_buffer_enabled(indio_dev))
+ iio_trigger_poll(st->trig);
+ else
+ complete(&st->completion);
return IRQ_HANDLED;
};
+static int ad4170_trigger_setup(struct iio_dev *indio_dev)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct device *dev = &st->spi->dev;
+ int ret;
+
+ st->trig = devm_iio_trigger_alloc(dev, "%s-trig%d",
+ indio_dev->name,
+ iio_device_id(indio_dev));
+ if (!st->trig)
+ return -ENOMEM;
+
+ st->trig->ops = &ad4170_trigger_ops;
+ st->trig->dev.parent = dev;
+
+ iio_trigger_set_drvdata(st->trig, indio_dev);
+ ret = devm_iio_trigger_register(dev, st->trig);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to register trigger\n");
+
+ indio_dev->trig = iio_trigger_get(st->trig);
+
+ return 0;
+}
+
static int ad4170_regulator_setup(struct ad4170_state *st)
{
struct device *dev = &st->spi->dev;
@@ -1789,8 +1988,22 @@ static int ad4170_probe(struct spi_device *spi)
IRQF_ONESHOT, indio_dev->name, indio_dev);
if (ret)
return ret;
+
+ ret = ad4170_trigger_setup(indio_dev);
+ if (ret)
+ return ret;
}
+ ret = ad4170_prepare_spi_message(st);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to prepare SPI message\n");
+
+ ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
+ &ad4170_trigger_handler,
+ &ad4170_buffer_ops);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to setup read buffer\n");
+
return devm_iio_device_register(dev, indio_dev);
}
--
2.47.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* Re: [PATCH v4 06/11] iio: adc: ad4170: Add support for buffered data capture
2025-06-02 11:38 ` [PATCH v4 06/11] iio: adc: ad4170: Add support for buffered data capture Marcelo Schmitt
@ 2025-06-07 17:06 ` Jonathan Cameron
2025-06-09 20:39 ` Marcelo Schmitt
0 siblings, 1 reply; 29+ messages in thread
From: Jonathan Cameron @ 2025-06-07 17:06 UTC (permalink / raw)
To: Marcelo Schmitt
Cc: linux-iio, devicetree, linux-gpio, linux-kernel, lars,
Michael.Hennerich, dlechner, nuno.sa, andy, robh, krzk+dt,
conor+dt, linus.walleij, brgl, marcelo.schmitt1
On Mon, 2 Jun 2025 08:38:46 -0300
Marcelo Schmitt <marcelo.schmitt@analog.com> wrote:
> Extend the AD4170 driver to allow buffered data capture in continuous read
> mode. In continuous read mode, the chip skips the instruction phase and
> outputs just ADC sample data, enabling faster sample rates to be reached.
> The internal channel sequencer always starts sampling from channel 0 and
> channel 0 must be enabled if more than one channel is selected for data
> capture. The scan mask validation callback checks if the aforementioned
> condition is met.
>
> Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
A comment inline about possibly relaxing the channel 0 constraint
as far as userspace is concerned anyway. Not necessary for now though.
> diff --git a/drivers/iio/adc/ad4170.c b/drivers/iio/adc/ad4170.c
> index 3d83c3ace569..86ef70acbf21 100644
> --- a/drivers/iio/adc/ad4170.c
> +++ b/drivers/iio/adc/ad4170.c
> @@ -13,7 +13,11 @@
> +static bool ad4170_validate_scan_mask(struct iio_dev *indio_dev,
> + const unsigned long *scan_mask)
> +{
> + unsigned int masklength = iio_get_masklength(indio_dev);
If this becomes a useability issue we could probably generative appropriate
available_scan_masks entries and let the demuxer in the IIO core deal with
dropping the unwanted first channel. That might be preferable to just
failing if the channel isn't enabled.
As a general rule, I think we've always used validate_scan_mask
to prevent too many channels being turned on, or incompatible sets of channels
rather than to prevent too few being enabled.
Anyhow that would be a relaxation of constraints so can be done if it
turns out to be needed later.
> +
> + /*
> + * The channel sequencer cycles through the enabled channels in
> + * sequential order, from channel 0 to channel 15, bypassing disabled
> + * channels. When more than one channel is enabled, channel 0 must
> + * always be enabled. See datasheet channel_en register description at
> + * page 95.
> + */
> + if (bitmap_weight(scan_mask, masklength) > 1)
> + return test_bit(0, scan_mask);
> +
> + return bitmap_weight(scan_mask, masklength) == 1;
> +}
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [PATCH v4 06/11] iio: adc: ad4170: Add support for buffered data capture
2025-06-07 17:06 ` Jonathan Cameron
@ 2025-06-09 20:39 ` Marcelo Schmitt
0 siblings, 0 replies; 29+ messages in thread
From: Marcelo Schmitt @ 2025-06-09 20:39 UTC (permalink / raw)
To: Jonathan Cameron
Cc: Marcelo Schmitt, linux-iio, devicetree, linux-gpio, linux-kernel,
lars, Michael.Hennerich, dlechner, nuno.sa, andy, robh, krzk+dt,
conor+dt, linus.walleij, brgl
...
> > diff --git a/drivers/iio/adc/ad4170.c b/drivers/iio/adc/ad4170.c
> > index 3d83c3ace569..86ef70acbf21 100644
> > --- a/drivers/iio/adc/ad4170.c
> > +++ b/drivers/iio/adc/ad4170.c
> > @@ -13,7 +13,11 @@
>
> > +static bool ad4170_validate_scan_mask(struct iio_dev *indio_dev,
> > + const unsigned long *scan_mask)
> > +{
> > + unsigned int masklength = iio_get_masklength(indio_dev);
>
> If this becomes a useability issue we could probably generative appropriate
> available_scan_masks entries and let the demuxer in the IIO core deal with
> dropping the unwanted first channel. That might be preferable to just
> failing if the channel isn't enabled.
Yes, we can do that. I also think that would probably be the preferred way from
the user's perspective. Though, that tinkering may result in a few more tens of
lines of code, which I'm reluctant to add, given the size of this set.
>
> As a general rule, I think we've always used validate_scan_mask
> to prevent too many channels being turned on, or incompatible sets of channels
> rather than to prevent too few being enabled.
>
> Anyhow that would be a relaxation of constraints so can be done if it
> turns out to be needed later.
>
Added to my list of patch ideas :)
> > +
> > + /*
> > + * The channel sequencer cycles through the enabled channels in
> > + * sequential order, from channel 0 to channel 15, bypassing disabled
> > + * channels. When more than one channel is enabled, channel 0 must
> > + * always be enabled. See datasheet channel_en register description at
> > + * page 95.
> > + */
> > + if (bitmap_weight(scan_mask, masklength) > 1)
> > + return test_bit(0, scan_mask);
> > +
> > + return bitmap_weight(scan_mask, masklength) == 1;
> > +}
^ permalink raw reply [flat|nested] 29+ messages in thread
* [PATCH v4 07/11] iio: adc: ad4170: Add clock provider support
2025-06-02 11:34 [PATCH v4 00/11] iio: adc: Add support for AD4170 series of ADCs Marcelo Schmitt
` (5 preceding siblings ...)
2025-06-02 11:38 ` [PATCH v4 06/11] iio: adc: ad4170: Add support for buffered data capture Marcelo Schmitt
@ 2025-06-02 11:39 ` Marcelo Schmitt
2025-06-02 11:39 ` [PATCH v4 08/11] iio: adc: ad4170: Add GPIO controller support Marcelo Schmitt
` (3 subsequent siblings)
10 siblings, 0 replies; 29+ messages in thread
From: Marcelo Schmitt @ 2025-06-02 11:39 UTC (permalink / raw)
To: linux-iio, devicetree, linux-gpio, linux-kernel
Cc: jic23, lars, Michael.Hennerich, dlechner, nuno.sa, andy, robh,
krzk+dt, conor+dt, linus.walleij, brgl, marcelo.schmitt1
The AD4170 chip can use an externally supplied clock at the XTAL2 pin, or
an external crystal connected to the XTAL1 and XTAL2 pins. Alternatively,
the AD4170 can provide its 16 MHz internal clock at the XTAL2 pin. In
addition, the chip has a programmable clock divider that allows dividing
the external or internal clock frequency, however, control for that is not
provided in this patch. Extend the AD4170 driver so it effectively uses the
provided external clock, if any, or supplies its own clock as a clock
provider.
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
---
Change log v3 -> v4
- Explicitly stated that clock divider (CLKDIV) control support is not provided.
- Skipped clock provider register if "#clock-cells" is not present.
Suggestions/comments not followed/applied:
> Shouldn't there be a dependency that if clocks is given, then clock-names is
> required.
It could be, but we have a default for clock-names so I think it's not needed.
> Do we need to claim direct mode here to avoid poking registers during a
> buffered read?
In this case, I don't think so. All of clock configuration is done during probe.
The IIO device will not be visible to user space at that moment. There should be
no need to protect register access during probe (unless another thread tries to
concurrently probe the device?).
> Why not just do the regmap_write() in ad4170_clock_select() to keep it all
> together?
ad4170_clock_select() has two return paths (one for internal and one for
external clock). We would have to duplicate the regmap_write() to have
that inside ad4170_clock_select().
> Seems like we would want to start in the AD4170_CLOCK_CTRL_CLOCKSEL_INT state.
I don't think so. We'll match clock-names either with 0 or 1 and that indicates
if the external clock is an input clock or a crystal. If it's ext-clk, we write
0x2 (2 + 0) to CLOCKSEL field. If it's xtal we write 0x3 (2 + 1).
drivers/iio/adc/Kconfig | 1 +
drivers/iio/adc/ad4170.c | 147 ++++++++++++++++++++++++++++++++++++++-
2 files changed, 147 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index b12dcc04c894..32e5177ceebe 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -91,6 +91,7 @@ config AD4170
select REGMAP_SPI
select IIO_BUFFER
select IIO_TRIGGERED_BUFFER
+ depends on COMMON_CLK
help
Say yes here to build support for Analog Devices AD4170 SPI analog
to digital converters (ADC).
diff --git a/drivers/iio/adc/ad4170.c b/drivers/iio/adc/ad4170.c
index 86ef70acbf21..2173e79ce96c 100644
--- a/drivers/iio/adc/ad4170.c
+++ b/drivers/iio/adc/ad4170.c
@@ -10,6 +10,8 @@
#include <linux/bitops.h>
#include <linux/bits.h>
#include <linux/cleanup.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
@@ -50,6 +52,7 @@
#define AD4170_CONFIG_A_REG 0x00
#define AD4170_DATA_24B_REG 0x1E
#define AD4170_PIN_MUXING_REG 0x69
+#define AD4170_CLOCK_CTRL_REG 0x6B
#define AD4170_ADC_CTRL_REG 0x71
#define AD4170_CHAN_EN_REG 0x79
#define AD4170_CHAN_SETUP_REG(x) (0x81 + 4 * (x))
@@ -70,6 +73,9 @@
/* AD4170_PIN_MUXING_REG */
#define AD4170_PIN_MUXING_DIG_AUX1_CTRL_MSK GENMASK(5, 4)
+/* AD4170_CLOCK_CTRL_REG */
+#define AD4170_CLOCK_CTRL_CLOCKSEL_MSK GENMASK(1, 0)
+
/* AD4170_ADC_CTRL_REG */
#define AD4170_ADC_CTRL_MULTI_DATA_REG_SEL_MSK BIT(7)
#define AD4170_ADC_CTRL_CONT_READ_MSK GENMASK(5, 4)
@@ -97,6 +103,12 @@
/* AD4170 register constants */
+/* AD4170_CLOCK_CTRL_REG constants */
+#define AD4170_CLOCK_CTRL_CLOCKSEL_INT 0x0
+#define AD4170_CLOCK_CTRL_CLOCKSEL_INT_OUT 0x1
+#define AD4170_CLOCK_CTRL_CLOCKSEL_EXT 0x2
+#define AD4170_CLOCK_CTRL_CLOCKSEL_EXT_XTAL 0x3
+
/* AD4170_CHAN_MAP_REG constants */
#define AD4170_CHAN_MAP_AIN(x) (x)
#define AD4170_CHAN_MAP_TEMP_SENSOR 17
@@ -143,6 +155,8 @@
/* Internal and external clock properties */
#define AD4170_INT_CLOCK_16MHZ (16 * HZ_PER_MHZ)
+#define AD4170_EXT_CLOCK_MHZ_MIN (1 * HZ_PER_MHZ)
+#define AD4170_EXT_CLOCK_MHZ_MAX (17 * HZ_PER_MHZ)
#define AD4170_NUM_PGA_OPTIONS 10
@@ -160,6 +174,7 @@ static const unsigned int ad4170_reg_size[] = {
[AD4170_CONFIG_A_REG] = 1,
[AD4170_DATA_24B_REG] = 3,
[AD4170_PIN_MUXING_REG] = 2,
+ [AD4170_CLOCK_CTRL_REG] = 2,
[AD4170_ADC_CTRL_REG] = 2,
[AD4170_CHAN_EN_REG] = 2,
/*
@@ -225,6 +240,10 @@ enum ad4170_regulator {
AD4170_MAX_SUP
};
+static const char *const ad4170_clk_sel[] = {
+ "ext-clk", "xtal",
+};
+
enum ad4170_int_pin_sel {
AD4170_INT_PIN_SDO,
AD4170_INT_PIN_DIG_AUX1,
@@ -327,6 +346,8 @@ struct ad4170_state {
struct completion completion;
int pins_fn[AD4170_NUM_ANALOG_PINS];
u32 int_pin_sel;
+ struct clk_hw int_clk_hw;
+ unsigned int clock_ctrl;
/*
* DMA (thus cache coherency maintenance) requires the transfer buffers
* to live in their own cache lines.
@@ -1610,13 +1631,137 @@ static int ad4170_parse_channels(struct iio_dev *indio_dev)
return 0;
}
+static struct ad4170_state *clk_hw_to_ad4170(struct clk_hw *hw)
+{
+ return container_of(hw, struct ad4170_state, int_clk_hw);
+}
+
+static unsigned long ad4170_sel_clk(struct ad4170_state *st,
+ unsigned int clk_sel)
+{
+ st->clock_ctrl &= ~AD4170_CLOCK_CTRL_CLOCKSEL_MSK;
+ st->clock_ctrl |= FIELD_PREP(AD4170_CLOCK_CTRL_CLOCKSEL_MSK, clk_sel);
+ return regmap_write(st->regmap, AD4170_CLOCK_CTRL_REG, st->clock_ctrl);
+}
+
+static unsigned long ad4170_clk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ return AD4170_INT_CLOCK_16MHZ;
+}
+
+static int ad4170_clk_output_is_enabled(struct clk_hw *hw)
+{
+ struct ad4170_state *st = clk_hw_to_ad4170(hw);
+ u32 clk_sel;
+
+ clk_sel = FIELD_GET(AD4170_CLOCK_CTRL_CLOCKSEL_MSK, st->clock_ctrl);
+ return clk_sel == AD4170_CLOCK_CTRL_CLOCKSEL_INT_OUT;
+}
+
+static int ad4170_clk_output_prepare(struct clk_hw *hw)
+{
+ struct ad4170_state *st = clk_hw_to_ad4170(hw);
+
+ return ad4170_sel_clk(st, AD4170_CLOCK_CTRL_CLOCKSEL_INT_OUT);
+}
+
+static void ad4170_clk_output_unprepare(struct clk_hw *hw)
+{
+ struct ad4170_state *st = clk_hw_to_ad4170(hw);
+
+ ad4170_sel_clk(st, AD4170_CLOCK_CTRL_CLOCKSEL_INT);
+}
+
+static const struct clk_ops ad4170_int_clk_ops = {
+ .recalc_rate = ad4170_clk_recalc_rate,
+ .is_enabled = ad4170_clk_output_is_enabled,
+ .prepare = ad4170_clk_output_prepare,
+ .unprepare = ad4170_clk_output_unprepare,
+};
+
+static int ad4170_register_clk_provider(struct iio_dev *indio_dev)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct device *dev = indio_dev->dev.parent;
+ struct clk_init_data init = {};
+ int ret;
+
+ if (device_property_read_string(dev, "clock-output-names", &init.name)) {
+ init.name = devm_kasprintf(dev, GFP_KERNEL, "%pfw",
+ dev_fwnode(dev));
+ if (!init.name)
+ return -ENOMEM;
+ }
+
+ init.ops = &ad4170_int_clk_ops;
+
+ st->int_clk_hw.init = &init;
+ ret = devm_clk_hw_register(dev, &st->int_clk_hw);
+ if (ret)
+ return ret;
+
+ return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
+ &st->int_clk_hw);
+}
+
+static int ad4170_clock_select(struct iio_dev *indio_dev)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct device *dev = &st->spi->dev;
+ struct clk *ext_clk;
+ int ret;
+
+ ext_clk = devm_clk_get_optional_enabled(dev, NULL);
+ if (IS_ERR(ext_clk))
+ return dev_err_probe(dev, PTR_ERR(ext_clk),
+ "Failed to get external clock\n");
+
+ if (!ext_clk) {
+ /* Use internal clock reference */
+ st->mclk_hz = AD4170_INT_CLOCK_16MHZ;
+ st->clock_ctrl |= FIELD_PREP(AD4170_CLOCK_CTRL_CLOCKSEL_MSK,
+ AD4170_CLOCK_CTRL_CLOCKSEL_INT_OUT);
+
+ if (!device_property_read_bool(&st->spi->dev, "#clock-cells"))
+ return 0;
+
+ return ad4170_register_clk_provider(indio_dev);
+ }
+
+ /* Read optional clock-names prop to specify the external clock type */
+ ret = device_property_match_property_string(dev, "clock-names",
+ ad4170_clk_sel,
+ ARRAY_SIZE(ad4170_clk_sel));
+
+ ret = ret < 0 ? 0 : ret; /* Default to external clock if no clock-names */
+ st->clock_ctrl |= FIELD_PREP(AD4170_CLOCK_CTRL_CLOCKSEL_MSK,
+ AD4170_CLOCK_CTRL_CLOCKSEL_EXT + ret);
+
+ st->mclk_hz = clk_get_rate(ext_clk);
+ if (st->mclk_hz < AD4170_EXT_CLOCK_MHZ_MIN ||
+ st->mclk_hz > AD4170_EXT_CLOCK_MHZ_MAX) {
+ return dev_err_probe(dev, -EINVAL,
+ "Invalid external clock frequency %u\n",
+ st->mclk_hz);
+ }
+
+ return 0;
+}
+
static int ad4170_parse_firmware(struct iio_dev *indio_dev)
{
struct ad4170_state *st = iio_priv(indio_dev);
struct device *dev = &st->spi->dev;
int reg_data, ret;
- st->mclk_hz = AD4170_INT_CLOCK_16MHZ;
+ ret = ad4170_clock_select(indio_dev);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to setup device clock\n");
+
+ ret = regmap_write(st->regmap, AD4170_CLOCK_CTRL_REG, st->clock_ctrl);
+ if (ret)
+ return ret;
/* On power on, device defaults to using SDO pin for data ready signal */
st->int_pin_sel = AD4170_INT_PIN_SDO;
--
2.47.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v4 08/11] iio: adc: ad4170: Add GPIO controller support
2025-06-02 11:34 [PATCH v4 00/11] iio: adc: Add support for AD4170 series of ADCs Marcelo Schmitt
` (6 preceding siblings ...)
2025-06-02 11:39 ` [PATCH v4 07/11] iio: adc: ad4170: Add clock provider support Marcelo Schmitt
@ 2025-06-02 11:39 ` Marcelo Schmitt
2025-06-02 11:39 ` [PATCH v4 09/11] iio: adc: ad4170: Add support for internal temperature sensor Marcelo Schmitt
` (2 subsequent siblings)
10 siblings, 0 replies; 29+ messages in thread
From: Marcelo Schmitt @ 2025-06-02 11:39 UTC (permalink / raw)
To: linux-iio, devicetree, linux-gpio, linux-kernel
Cc: jic23, lars, Michael.Hennerich, dlechner, nuno.sa, andy, robh,
krzk+dt, conor+dt, linus.walleij, brgl, marcelo.schmitt1,
Bartosz Golaszewski
The AD4170 has four multifunctional pins that can be used as GPIOs. The
GPIO functionality can be accessed when the AD4170 chip is not busy
performing continuous data capture or handling any other register
read/write request. Also, the AD4170 does not provide any interrupt based
on GPIO pin states so AD4170 GPIOs can't be used as interrupt sources.
Implement gpio_chip callbacks to make AD4170 GPIO pins controllable through
the gpiochip interface.
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
---
Change log v3 -> v4
- Made AD4170 depend on GPIOLIB.
drivers/iio/adc/Kconfig | 1 +
drivers/iio/adc/ad4170.c | 224 ++++++++++++++++++++++++++++++++++++++-
2 files changed, 224 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 32e5177ceebe..0c16b2d5947d 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -92,6 +92,7 @@ config AD4170
select IIO_BUFFER
select IIO_TRIGGERED_BUFFER
depends on COMMON_CLK
+ depends on GPIOLIB
help
Say yes here to build support for Analog Devices AD4170 SPI analog
to digital converters (ADC).
diff --git a/drivers/iio/adc/ad4170.c b/drivers/iio/adc/ad4170.c
index 2173e79ce96c..3aa1553c0e3d 100644
--- a/drivers/iio/adc/ad4170.c
+++ b/drivers/iio/adc/ad4170.c
@@ -15,6 +15,7 @@
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
+#include <linux/gpio/driver.h>
#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
#include <linux/iio/trigger.h>
@@ -63,6 +64,9 @@
#define AD4170_FILTER_FS_REG(x) (0xC7 + 14 * (x))
#define AD4170_OFFSET_REG(x) (0xCA + 14 * (x))
#define AD4170_GAIN_REG(x) (0xCD + 14 * (x))
+#define AD4170_GPIO_MODE_REG 0x191
+#define AD4170_GPIO_OUTPUT_REG 0x193
+#define AD4170_GPIO_INPUT_REG 0x195
#define AD4170_ADC_CTRL_CONT_READ_EXIT_REG 0x200 /* virtual reg */
#define AD4170_REG_READ_MASK BIT(14)
@@ -101,6 +105,12 @@
/* AD4170_FILTER_REG */
#define AD4170_FILTER_FILTER_TYPE_MSK GENMASK(3, 0)
+/* AD4170_GPIO_MODE_REG */
+#define AD4170_GPIO_MODE_GPIO0_MSK GENMASK(1, 0)
+#define AD4170_GPIO_MODE_GPIO1_MSK GENMASK(3, 2)
+#define AD4170_GPIO_MODE_GPIO2_MSK GENMASK(5, 4)
+#define AD4170_GPIO_MODE_GPIO3_MSK GENMASK(7, 6)
+
/* AD4170 register constants */
/* AD4170_CLOCK_CTRL_REG constants */
@@ -141,9 +151,14 @@
#define AD4170_FILTER_FILTER_TYPE_SINC5 0x4
#define AD4170_FILTER_FILTER_TYPE_SINC3 0x6
+/* AD4170_GPIO_MODE_REG constants */
+#define AD4170_GPIO_MODE_GPIO_INPUT 1
+#define AD4170_GPIO_MODE_GPIO_OUTPUT 2
+
/* Device properties and auxiliary constants */
#define AD4170_NUM_ANALOG_PINS 9
+#define AD4170_NUM_GPIO_PINS 4
#define AD4170_MAX_CHANNELS 16
#define AD4170_MAX_ANALOG_PINS 8
#define AD4170_MAX_SETUPS 8
@@ -170,6 +185,9 @@
#define AD4170_ADC_CTRL_CONT_READ_EXIT 0xA5
+/* GPIO pin functions */
+#define AD4170_GPIO_UNASSIGNED 0x00
+
static const unsigned int ad4170_reg_size[] = {
[AD4170_CONFIG_A_REG] = 1,
[AD4170_DATA_24B_REG] = 3,
@@ -207,6 +225,9 @@ static const unsigned int ad4170_reg_size[] = {
[AD4170_OFFSET_REG(5) ... AD4170_GAIN_REG(5)] = 3,
[AD4170_OFFSET_REG(6) ... AD4170_GAIN_REG(6)] = 3,
[AD4170_OFFSET_REG(7) ... AD4170_GAIN_REG(7)] = 3,
+ [AD4170_GPIO_MODE_REG] = 2,
+ [AD4170_GPIO_OUTPUT_REG] = 2,
+ [AD4170_GPIO_INPUT_REG] = 2,
[AD4170_ADC_CTRL_CONT_READ_EXIT_REG] = 0,
};
@@ -347,7 +368,9 @@ struct ad4170_state {
int pins_fn[AD4170_NUM_ANALOG_PINS];
u32 int_pin_sel;
struct clk_hw int_clk_hw;
+ struct gpio_chip gpiochip;
unsigned int clock_ctrl;
+ int gpio_fn[AD4170_NUM_GPIO_PINS];
/*
* DMA (thus cache coherency maintenance) requires the transfer buffers
* to live in their own cache lines.
@@ -1468,6 +1491,194 @@ static int ad4170_soft_reset(struct ad4170_state *st)
return 0;
}
+static int ad4170_gpio_get(struct gpio_chip *gc, unsigned int offset)
+{
+ struct iio_dev *indio_dev = gpiochip_get_data(gc);
+ struct ad4170_state *st = iio_priv(indio_dev);
+ unsigned int val;
+ int ret;
+
+ if (!iio_device_claim_direct(indio_dev))
+ return -EBUSY;
+
+ ret = regmap_read(st->regmap, AD4170_GPIO_MODE_REG, &val);
+ if (ret)
+ goto err_release;
+
+ /*
+ * If the GPIO is configured as an input, read the current value from
+ * AD4170_GPIO_INPUT_REG. Otherwise, read the input value from
+ * AD4170_GPIO_OUTPUT_REG.
+ */
+ if (val & BIT(offset * 2))
+ ret = regmap_read(st->regmap, AD4170_GPIO_INPUT_REG, &val);
+ else
+ ret = regmap_read(st->regmap, AD4170_GPIO_OUTPUT_REG, &val);
+ if (ret)
+ goto err_release;
+
+ ret = !!(val & BIT(offset));
+err_release:
+ iio_device_release_direct(indio_dev);
+
+ return ret;
+}
+
+static int ad4170_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
+{
+ struct iio_dev *indio_dev = gpiochip_get_data(gc);
+ struct ad4170_state *st = iio_priv(indio_dev);
+ int ret;
+
+ if (!iio_device_claim_direct(indio_dev))
+ return -EBUSY;
+
+ ret = regmap_assign_bits(st->regmap, AD4170_GPIO_OUTPUT_REG,
+ BIT(offset), !!value);
+
+ iio_device_release_direct(indio_dev);
+ return ret;
+}
+
+static int ad4170_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+ struct iio_dev *indio_dev = gpiochip_get_data(gc);
+ struct ad4170_state *st = iio_priv(indio_dev);
+ unsigned int val;
+ int ret;
+
+ if (!iio_device_claim_direct(indio_dev))
+ return -EBUSY;
+
+ ret = regmap_read(st->regmap, AD4170_GPIO_MODE_REG, &val);
+ if (ret)
+ goto err_release;
+
+ if (val & BIT(offset * 2 + 1))
+ ret = GPIO_LINE_DIRECTION_OUT;
+ else
+ ret = GPIO_LINE_DIRECTION_IN;
+
+err_release:
+ iio_device_release_direct(indio_dev);
+
+ return ret;
+}
+
+static int ad4170_gpio_direction_input(struct gpio_chip *gc, unsigned int offset)
+{
+ struct iio_dev *indio_dev = gpiochip_get_data(gc);
+ struct ad4170_state *st = iio_priv(indio_dev);
+ unsigned long gpio_mask;
+ int ret;
+
+ if (!iio_device_claim_direct(indio_dev))
+ return -EBUSY;
+
+ switch (offset) {
+ case 0:
+ gpio_mask = AD4170_GPIO_MODE_GPIO0_MSK;
+ break;
+ case 1:
+ gpio_mask = AD4170_GPIO_MODE_GPIO1_MSK;
+ break;
+ case 2:
+ gpio_mask = AD4170_GPIO_MODE_GPIO2_MSK;
+ break;
+ case 3:
+ gpio_mask = AD4170_GPIO_MODE_GPIO3_MSK;
+ break;
+ default:
+ ret = -EINVAL;
+ goto err_release;
+ }
+ ret = regmap_update_bits(st->regmap, AD4170_GPIO_MODE_REG, gpio_mask,
+ AD4170_GPIO_MODE_GPIO_INPUT << (2 * offset));
+
+err_release:
+ iio_device_release_direct(indio_dev);
+
+ return ret;
+}
+
+static int ad4170_gpio_direction_output(struct gpio_chip *gc,
+ unsigned int offset, int value)
+{
+ struct iio_dev *indio_dev = gpiochip_get_data(gc);
+ struct ad4170_state *st = iio_priv(indio_dev);
+ unsigned long gpio_mask;
+ int ret;
+
+ ret = ad4170_gpio_set(gc, offset, value);
+ if (ret)
+ return ret;
+
+ if (!iio_device_claim_direct(indio_dev))
+ return -EBUSY;
+
+ switch (offset) {
+ case 0:
+ gpio_mask = AD4170_GPIO_MODE_GPIO0_MSK;
+ break;
+ case 1:
+ gpio_mask = AD4170_GPIO_MODE_GPIO1_MSK;
+ break;
+ case 2:
+ gpio_mask = AD4170_GPIO_MODE_GPIO2_MSK;
+ break;
+ case 3:
+ gpio_mask = AD4170_GPIO_MODE_GPIO3_MSK;
+ break;
+ default:
+ ret = -EINVAL;
+ goto err_release;
+ }
+ ret = regmap_update_bits(st->regmap, AD4170_GPIO_MODE_REG, gpio_mask,
+ AD4170_GPIO_MODE_GPIO_OUTPUT << (2 * offset));
+
+err_release:
+ iio_device_release_direct(indio_dev);
+
+ return ret;
+}
+
+static int ad4170_gpio_init_valid_mask(struct gpio_chip *gc,
+ unsigned long *valid_mask,
+ unsigned int ngpios)
+{
+ struct ad4170_state *st = gpiochip_get_data(gc);
+ unsigned int i;
+
+ /* Only expose GPIOs that were not assigned any other function. */
+ for (i = 0; i < ngpios; i++) {
+ bool valid = st->gpio_fn[i] == AD4170_GPIO_UNASSIGNED;
+
+ __assign_bit(i, valid_mask, valid);
+ }
+
+ return 0;
+}
+
+static int ad4170_gpio_init(struct iio_dev *indio_dev)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+
+ st->gpiochip.label = "ad4170_gpios";
+ st->gpiochip.base = -1;
+ st->gpiochip.ngpio = AD4170_NUM_GPIO_PINS;
+ st->gpiochip.parent = &st->spi->dev;
+ st->gpiochip.can_sleep = true;
+ st->gpiochip.init_valid_mask = ad4170_gpio_init_valid_mask;
+ st->gpiochip.get_direction = ad4170_gpio_get_direction;
+ st->gpiochip.direction_input = ad4170_gpio_direction_input;
+ st->gpiochip.direction_output = ad4170_gpio_direction_output;
+ st->gpiochip.get = ad4170_gpio_get;
+ st->gpiochip.set_rv = ad4170_gpio_set;
+ st->gpiochip.owner = THIS_MODULE;
+
+ return devm_gpiochip_add_data(&st->spi->dev, &st->gpiochip, indio_dev);
+}
+
static int ad4170_parse_reference(struct ad4170_state *st,
struct fwnode_handle *child,
struct ad4170_setup *setup)
@@ -1781,7 +1992,18 @@ static int ad4170_parse_firmware(struct iio_dev *indio_dev)
if (ret)
return ret;
- return ad4170_parse_channels(indio_dev);
+ ret = ad4170_parse_channels(indio_dev);
+ if (ret)
+ return ret;
+
+ /* Only create a GPIO chip if flagged for it */
+ if (device_property_read_bool(&st->spi->dev, "gpio-controller")) {
+ ret = ad4170_gpio_init(indio_dev);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
}
static int ad4170_initial_config(struct iio_dev *indio_dev)
--
2.47.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v4 09/11] iio: adc: ad4170: Add support for internal temperature sensor
2025-06-02 11:34 [PATCH v4 00/11] iio: adc: Add support for AD4170 series of ADCs Marcelo Schmitt
` (7 preceding siblings ...)
2025-06-02 11:39 ` [PATCH v4 08/11] iio: adc: ad4170: Add GPIO controller support Marcelo Schmitt
@ 2025-06-02 11:39 ` Marcelo Schmitt
2025-06-02 11:40 ` [PATCH v4 10/11] iio: adc: ad4170: Add support for weigh scale and RTD sensors Marcelo Schmitt
2025-06-02 11:40 ` [PATCH v4 11/11] iio: adc: ad4170: Add timestamp channel Marcelo Schmitt
10 siblings, 0 replies; 29+ messages in thread
From: Marcelo Schmitt @ 2025-06-02 11:39 UTC (permalink / raw)
To: linux-iio, devicetree, linux-gpio, linux-kernel
Cc: jic23, lars, Michael.Hennerich, dlechner, nuno.sa, andy, robh,
krzk+dt, conor+dt, linus.walleij, brgl, marcelo.schmitt1
The AD4170 has an internal temperature sensor that can be read using the
ADC. Whenever possible, configure an IIO channel to provide the chip's
temperature.
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
---
No changes since v3.
drivers/iio/adc/ad4170.c | 72 ++++++++++++++++++++++++++++++++++++++--
1 file changed, 69 insertions(+), 3 deletions(-)
diff --git a/drivers/iio/adc/ad4170.c b/drivers/iio/adc/ad4170.c
index 3aa1553c0e3d..6e17f47a78bf 100644
--- a/drivers/iio/adc/ad4170.c
+++ b/drivers/iio/adc/ad4170.c
@@ -878,6 +878,27 @@ static const struct iio_chan_spec ad4170_channel_template = {
},
};
+static const struct iio_chan_spec ad4170_temp_channel_template = {
+ .type = IIO_TEMP,
+ .indexed = 0,
+ .channel = 17,
+ .channel2 = 17,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_OFFSET) |
+ BIT(IIO_CHAN_INFO_CALIBSCALE) |
+ BIT(IIO_CHAN_INFO_CALIBBIAS) |
+ BIT(IIO_CHAN_INFO_SAMP_FREQ),
+ .info_mask_separate_available = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+ .scan_type = {
+ .sign = 's',
+ .realbits = 24,
+ .storagebits = 32,
+ .shift = 8,
+ .endianness = IIO_BE,
+ },
+};
+
/*
* Receives the number of a multiplexed AD4170 input (ain_n), and stores the
* voltage (in µV) of the specified input into ain_voltage. If the input number
@@ -1177,9 +1198,27 @@ static int ad4170_read_raw(struct iio_dev *indio_dev,
return ret;
case IIO_CHAN_INFO_SCALE:
pga = FIELD_GET(AD4170_AFE_PGA_GAIN_MSK, setup->afe);
- *val = chan_info->scale_tbl[pga][0];
- *val2 = chan_info->scale_tbl[pga][1];
- return IIO_VAL_INT_PLUS_NANO;
+ switch (chan->type) {
+ case IIO_VOLTAGE:
+ *val = chan_info->scale_tbl[pga][0];
+ *val2 = chan_info->scale_tbl[pga][1];
+ return IIO_VAL_INT_PLUS_NANO;
+
+ case IIO_TEMP:
+ /*
+ * The scale_tbl converts output codes to mV units so
+ * multiply by MILLI to make the factor convert to µV.
+ * Then, apply the temperature sensor change sensitivity
+ * of 477 μV/K. Finally, multiply the result by MILLI
+ * again to comply with milli degrees Celsius IIO ABI.
+ */
+ *val = 0;
+ *val2 = DIV_ROUND_CLOSEST(chan_info->scale_tbl[pga][1] * MILLI, 477) *
+ MILLI;
+ return IIO_VAL_INT_PLUS_NANO;
+ default:
+ return -EINVAL;
+ }
case IIO_CHAN_INFO_OFFSET:
pga = FIELD_GET(AD4170_AFE_PGA_GAIN_MSK, setup->afe);
*val = chan_info->offset_tbl[pga];
@@ -1830,12 +1869,39 @@ static int ad4170_parse_channels(struct iio_dev *indio_dev)
if (num_channels > AD4170_MAX_CHANNELS)
return dev_err_probe(dev, -EINVAL, "Too many channels\n");
+ /* Add one for temperature */
+ num_channels = min(num_channels + 1, AD4170_MAX_CHANNELS);
+
device_for_each_child_node_scoped(dev, child) {
ret = ad4170_parse_channel_node(indio_dev, child, chan_num++);
if (ret)
return ret;
}
+ /*
+ * Add internal temperature sensor channel if the maximum number of
+ * channels has not been reached.
+ */
+ if (num_channels < AD4170_MAX_CHANNELS) {
+ struct ad4170_setup *setup = &st->chan_infos[chan_num].setup;
+
+ st->chans[chan_num] = ad4170_temp_channel_template;
+ st->chans[chan_num].address = chan_num;
+ st->chans[chan_num].scan_index = chan_num;
+
+ st->chan_infos[chan_num].setup_num = AD4170_INVALID_SETUP;
+ st->chan_infos[chan_num].initialized = true;
+
+ setup->afe |= FIELD_PREP(AD4170_AFE_REF_SELECT_MSK,
+ AD4170_REF_AVDD);
+
+ ret = ad4170_get_input_range(st, &st->chans[chan_num], chan_num,
+ AD4170_REF_AVDD);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Invalid input config\n");
+
+ st->chan_infos[chan_num].input_range_uv = ret;
+ }
indio_dev->num_channels = num_channels;
indio_dev->channels = st->chans;
--
2.47.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v4 10/11] iio: adc: ad4170: Add support for weigh scale and RTD sensors
2025-06-02 11:34 [PATCH v4 00/11] iio: adc: Add support for AD4170 series of ADCs Marcelo Schmitt
` (8 preceding siblings ...)
2025-06-02 11:39 ` [PATCH v4 09/11] iio: adc: ad4170: Add support for internal temperature sensor Marcelo Schmitt
@ 2025-06-02 11:40 ` Marcelo Schmitt
2025-06-07 17:15 ` Jonathan Cameron
2025-06-02 11:40 ` [PATCH v4 11/11] iio: adc: ad4170: Add timestamp channel Marcelo Schmitt
10 siblings, 1 reply; 29+ messages in thread
From: Marcelo Schmitt @ 2025-06-02 11:40 UTC (permalink / raw)
To: linux-iio, devicetree, linux-gpio, linux-kernel
Cc: jic23, lars, Michael.Hennerich, dlechner, nuno.sa, andy, robh,
krzk+dt, conor+dt, linus.walleij, brgl, marcelo.schmitt1
The AD4170 design has features to aid interfacing with weigh scale and RTD
sensors that are expected to be setup with external circuitry for proper
sensor operation. A key characteristic of those sensors is that the circuit
they are in must be excited with a pair of signals. The external circuit
can be excited either by voltage supply or by AD4170 excitation signals.
The sensor can then be read through a different pair of lines that are
connected to AD4170 ADC.
Configure AD4170 to handle external circuit sensors.
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
---
Change log v3 -> v4
- Update to string adi,sensor-type dt property.
- Adapted external sensor dt prop parsing to work with the updated version of those props.
drivers/iio/adc/ad4170.c | 500 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 494 insertions(+), 6 deletions(-)
diff --git a/drivers/iio/adc/ad4170.c b/drivers/iio/adc/ad4170.c
index 6e17f47a78bf..23b634d324a7 100644
--- a/drivers/iio/adc/ad4170.c
+++ b/drivers/iio/adc/ad4170.c
@@ -64,6 +64,8 @@
#define AD4170_FILTER_FS_REG(x) (0xC7 + 14 * (x))
#define AD4170_OFFSET_REG(x) (0xCA + 14 * (x))
#define AD4170_GAIN_REG(x) (0xCD + 14 * (x))
+#define AD4170_V_BIAS_REG 0x135
+#define AD4170_CURRENT_SRC_REG(x) (0x139 + 2 * (x))
#define AD4170_GPIO_MODE_REG 0x191
#define AD4170_GPIO_OUTPUT_REG 0x193
#define AD4170_GPIO_INPUT_REG 0x195
@@ -95,6 +97,10 @@
#define AD4170_CHAN_MAP_AINP_MSK GENMASK(12, 8)
#define AD4170_CHAN_MAP_AINM_MSK GENMASK(4, 0)
+/* AD4170_MISC_REG */
+#define AD4170_MISC_CHOP_IEXC_MSK GENMASK(15, 14)
+#define AD4170_MISC_CHOP_ADC_MSK GENMASK(9, 8)
+
/* AD4170_AFE_REG */
#define AD4170_AFE_REF_BUF_M_MSK GENMASK(11, 10)
#define AD4170_AFE_REF_BUF_P_MSK GENMASK(9, 8)
@@ -105,12 +111,19 @@
/* AD4170_FILTER_REG */
#define AD4170_FILTER_FILTER_TYPE_MSK GENMASK(3, 0)
+/* AD4170_CURRENT_SRC_REG */
+#define AD4170_CURRENT_SRC_I_OUT_PIN_MSK GENMASK(12, 8)
+#define AD4170_CURRENT_SRC_I_OUT_VAL_MSK GENMASK(2, 0)
+
/* AD4170_GPIO_MODE_REG */
#define AD4170_GPIO_MODE_GPIO0_MSK GENMASK(1, 0)
#define AD4170_GPIO_MODE_GPIO1_MSK GENMASK(3, 2)
#define AD4170_GPIO_MODE_GPIO2_MSK GENMASK(5, 4)
#define AD4170_GPIO_MODE_GPIO3_MSK GENMASK(7, 6)
+/* AD4170_GPIO_OUTPUT_REG */
+#define AD4170_GPIO_OUTPUT_GPIO_MSK(x) BIT(x)
+
/* AD4170 register constants */
/* AD4170_CLOCK_CTRL_REG constants */
@@ -134,6 +147,11 @@
#define AD4170_CHAN_MAP_REFIN2_N 28
#define AD4170_CHAN_MAP_REFOUT 29
+/* AD4170_MISC_REG constants */
+#define AD4170_MISC_CHOP_IEXC_PAIR1 0x1
+#define AD4170_MISC_CHOP_IEXC_PAIR2 0x2
+#define AD4170_MISC_CHOP_IEXC_BOTH 0x3
+
/* AD4170_PIN_MUXING_REG constants */
#define AD4170_PIN_MUXING_DIG_AUX1_DISABLED 0x0
#define AD4170_PIN_MUXING_DIG_AUX1_RDY 0x1
@@ -151,6 +169,10 @@
#define AD4170_FILTER_FILTER_TYPE_SINC5 0x4
#define AD4170_FILTER_FILTER_TYPE_SINC3 0x6
+/* AD4170_CURRENT_SRC_REG constants */
+#define AD4170_CURRENT_SRC_I_OUT_PIN_AIN(x) (x)
+#define AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(x) ((x) + 17)
+
/* AD4170_GPIO_MODE_REG constants */
#define AD4170_GPIO_MODE_GPIO_INPUT 1
#define AD4170_GPIO_MODE_GPIO_OUTPUT 2
@@ -164,6 +186,7 @@
#define AD4170_MAX_SETUPS 8
#define AD4170_INVALID_SETUP 9
#define AD4170_SPI_MAX_XFER_LEN 6
+#define AD4170_NUM_CURRENT_SRC 4
#define AD4170_DEFAULT_SAMP_RATE (125 * HZ_PER_KHZ)
#define AD4170_INT_REF_2_5V 2500000
@@ -185,8 +208,19 @@
#define AD4170_ADC_CTRL_CONT_READ_EXIT 0xA5
+/* Analog pin functions */
+#define AD4170_PIN_UNASSIGNED 0x00
+#define AD4170_PIN_ANALOG_IN 0x01
+#define AD4170_PIN_CURRENT_OUT 0x02
+#define AD4170_PIN_VBIAS 0x04
+
/* GPIO pin functions */
#define AD4170_GPIO_UNASSIGNED 0x00
+#define AD4170_GPIO_AC_EXCITATION 0x02
+#define AD4170_GPIO_OUTPUT 0x04
+
+/* Current source */
+#define AD4170_CURRENT_SRC_DISABLED 0xFF
static const unsigned int ad4170_reg_size[] = {
[AD4170_CONFIG_A_REG] = 1,
@@ -225,6 +259,8 @@ static const unsigned int ad4170_reg_size[] = {
[AD4170_OFFSET_REG(5) ... AD4170_GAIN_REG(5)] = 3,
[AD4170_OFFSET_REG(6) ... AD4170_GAIN_REG(6)] = 3,
[AD4170_OFFSET_REG(7) ... AD4170_GAIN_REG(7)] = 3,
+ [AD4170_V_BIAS_REG] = 2,
+ [AD4170_CURRENT_SRC_REG(0) ... AD4170_CURRENT_SRC_REG(3)] = 2,
[AD4170_GPIO_MODE_REG] = 2,
[AD4170_GPIO_OUTPUT_REG] = 2,
[AD4170_GPIO_INPUT_REG] = 2,
@@ -287,6 +323,41 @@ static const unsigned int ad4170_sinc5_filt_fs_tbl[] = {
1, 2, 4, 8, 12, 16, 20, 40, 48, 80, 100, 256,
};
+static const unsigned int ad4170_iout_pin_tbl[] = {
+ AD4170_CURRENT_SRC_I_OUT_PIN_AIN(0),
+ AD4170_CURRENT_SRC_I_OUT_PIN_AIN(1),
+ AD4170_CURRENT_SRC_I_OUT_PIN_AIN(2),
+ AD4170_CURRENT_SRC_I_OUT_PIN_AIN(3),
+ AD4170_CURRENT_SRC_I_OUT_PIN_AIN(4),
+ AD4170_CURRENT_SRC_I_OUT_PIN_AIN(5),
+ AD4170_CURRENT_SRC_I_OUT_PIN_AIN(6),
+ AD4170_CURRENT_SRC_I_OUT_PIN_AIN(7),
+ AD4170_CURRENT_SRC_I_OUT_PIN_AIN(8),
+ AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(0),
+ AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(1),
+ AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(2),
+ AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(3),
+};
+
+static const unsigned int ad4170_iout_current_ua_tbl[] = {
+ 0, 10, 50, 100, 250, 500, 1000, 1500,
+};
+
+enum ad4170_sensor_enum {
+ AD4170_ADC_SENSOR = 0,
+ AD4170_WEIGH_SCALE_SENSOR = 1,
+ AD4170_RTD_SENSOR = 2,
+ AD4170_THERMOCOUPLE_SENSOR = 3,
+};
+
+/* maps adi,sensor-type property value to enum */
+static const char * const ad4170_sensor_type[] = {
+ [AD4170_ADC_SENSOR] = "adc",
+ [AD4170_WEIGH_SCALE_SENSOR] = "weighscale",
+ [AD4170_RTD_SENSOR] = "rtd",
+ [AD4170_THERMOCOUPLE_SENSOR] = "thermocouple",
+};
+
struct ad4170_chip_info {
const char *name;
};
@@ -371,6 +442,7 @@ struct ad4170_state {
struct gpio_chip gpiochip;
unsigned int clock_ctrl;
int gpio_fn[AD4170_NUM_GPIO_PINS];
+ unsigned int cur_src_pins[AD4170_NUM_CURRENT_SRC];
/*
* DMA (thus cache coherency maintenance) requires the transfer buffers
* to live in their own cache lines.
@@ -913,6 +985,19 @@ static int ad4170_get_ain_voltage_uv(struct ad4170_state *st, int ain_n,
int v_diff;
*ain_voltage = 0;
+ /*
+ * The voltage bias (vbias) sets the common-mode voltage of the channel
+ * to (AVDD + AVSS)/2. If provided, AVSS supply provides the magnitude
+ * (absolute value) of the negative voltage supplied to the AVSS pin.
+ * So, we do AVDD - AVSS to compute the DC voltage generated by the bias
+ * voltage generator.
+ */
+ if (st->pins_fn[ain_n] & AD4170_PIN_VBIAS) {
+ int v_diff = st->vrefs_uv[AD4170_AVDD_SUP] - st->vrefs_uv[AD4170_AVSS_SUP];
+ *ain_voltage = v_diff / 2;
+ return 0;
+ }
+
if (ain_n <= AD4170_CHAN_MAP_TEMP_SENSOR)
return 0;
@@ -967,6 +1052,19 @@ static int ad4170_get_ain_voltage_uv(struct ad4170_state *st, int ain_n,
}
}
+static int ad4170_validate_analog_input(struct ad4170_state *st, int pin)
+{
+ if (pin <= AD4170_MAX_ANALOG_PINS) {
+ if (st->pins_fn[pin] & AD4170_PIN_CURRENT_OUT)
+ return dev_err_probe(&st->spi->dev, -EINVAL,
+ "Pin %d already used with fn %u.\n",
+ pin, st->pins_fn[pin]);
+
+ st->pins_fn[pin] |= AD4170_PIN_ANALOG_IN;
+ }
+ return 0;
+}
+
static int ad4170_validate_channel_input(struct ad4170_state *st, int pin, bool com)
{
/* Check common-mode input pin is mapped to a special input. */
@@ -981,7 +1079,7 @@ static int ad4170_validate_channel_input(struct ad4170_state *st, int pin, bool
"Invalid analog input pin number. %d\n",
pin);
- return 0;
+ return ad4170_validate_analog_input(st, pin);
}
/*
@@ -1718,6 +1816,373 @@ static int ad4170_gpio_init(struct iio_dev *indio_dev)
return devm_gpiochip_add_data(&st->spi->dev, &st->gpiochip, indio_dev);
}
+static int ad4170_validate_excitation_pin(struct ad4170_state *st, u32 pin)
+{
+ struct device *dev = &st->spi->dev;
+ unsigned int i;
+
+ /* Check the pin number is valid */
+ for (i = 0; i < ARRAY_SIZE(ad4170_iout_pin_tbl); i++)
+ if (ad4170_iout_pin_tbl[i] == pin)
+ break;
+
+ if (i == ARRAY_SIZE(ad4170_iout_pin_tbl))
+ return dev_err_probe(dev, -EINVAL,
+ "Invalid excitation pin: %u\n",
+ pin);
+
+ /* Check the pin is available */
+ if (pin <= AD4170_MAX_ANALOG_PINS) {
+ if (st->pins_fn[pin] != AD4170_PIN_UNASSIGNED)
+ return dev_err_probe(dev, -EINVAL,
+ "Pin %u already used with fn %u\n",
+ pin, st->pins_fn[pin]);
+
+ st->pins_fn[pin] |= AD4170_PIN_CURRENT_OUT;
+ } else {
+ unsigned int gpio = pin - AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(0);
+
+ if (st->gpio_fn[gpio] != AD4170_GPIO_UNASSIGNED)
+ return dev_err_probe(dev, -EINVAL,
+ "GPIO %u already used with fn %u\n",
+ gpio, st->gpio_fn[gpio]);
+
+ st->gpio_fn[gpio] |= AD4170_GPIO_AC_EXCITATION;
+ }
+
+ return 0;
+}
+
+static int ad4170_validate_excitation_pins(struct ad4170_state *st,
+ u32 *exc_pins, int num_exc_pins)
+{
+ unsigned int i;
+ int ret;
+
+ for (i = 0; i < num_exc_pins; i++) {
+ unsigned int pin = exc_pins[i];
+
+ ret = ad4170_validate_excitation_pin(st, pin);
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
+static const char *const ad4170_i_out_pin_dt_props[] = {
+ "adi,excitation-pin-0",
+ "adi,excitation-pin-1",
+ "adi,excitation-pin-2",
+ "adi,excitation-pin-3",
+};
+
+static const char *const ad4170_i_out_val_dt_props[] = {
+ "adi,excitation-current-0-microamp",
+ "adi,excitation-current-1-microamp",
+ "adi,excitation-current-2-microamp",
+ "adi,excitation-current-3-microamp",
+};
+
+/*
+ * Parses firmware data describing output current source setup. There are 4
+ * excitation currents (IOUT0 to IOUT3) that can be configured independently.
+ * Excitation currents are added if they are output on the same pin.
+ */
+static int ad4170_parse_exc_current(struct ad4170_state *st,
+ struct fwnode_handle *child,
+ unsigned int *exc_pins,
+ unsigned int *exc_curs,
+ unsigned int *num_exc_pins)
+{
+ struct device *dev = &st->spi->dev;
+ unsigned int num_pins, i, j;
+ u32 pin, val;
+ int ret;
+
+ num_pins = 0;
+ for (i = 0; i < AD4170_NUM_CURRENT_SRC; i++) {
+ /* Parse excitation current output pin properties. */
+ pin = AD4170_CURRENT_SRC_I_OUT_PIN_AIN(0);
+ ret = fwnode_property_read_u32(child, ad4170_i_out_pin_dt_props[i],
+ &pin);
+ if (ret)
+ continue;
+
+ exc_pins[num_pins] = pin;
+
+ /* Parse excitation current value properties. */
+ val = ad4170_iout_current_ua_tbl[0];
+ fwnode_property_read_u32(child,
+ ad4170_i_out_val_dt_props[i], &val);
+
+ for (j = 0; j < ARRAY_SIZE(ad4170_iout_current_ua_tbl); j++)
+ if (ad4170_iout_current_ua_tbl[j] == val)
+ break;
+
+ if (j == ARRAY_SIZE(ad4170_iout_current_ua_tbl))
+ return dev_err_probe(dev, -EINVAL, "Invalid %s: %uuA\n",
+ ad4170_i_out_val_dt_props[i], val);
+
+ exc_curs[num_pins] = j;
+ num_pins++;
+ }
+ *num_exc_pins = num_pins;
+
+ return 0;
+}
+
+static int ad4170_setup_current_src(struct ad4170_state *st,
+ struct fwnode_handle *child,
+ struct ad4170_setup *setup, u32 *exc_pins,
+ unsigned int *exc_curs, int num_exc_pins,
+ bool ac_excited)
+{
+ unsigned int exc_cur_pair, i, j;
+ int ret;
+
+ for (i = 0; i < num_exc_pins; i++) {
+ unsigned int exc_cur = exc_curs[i];
+ unsigned int pin = exc_pins[i];
+ unsigned int current_src = 0;
+
+ for (j = 0; j < AD4170_NUM_CURRENT_SRC; j++)
+ if (st->cur_src_pins[j] == AD4170_CURRENT_SRC_DISABLED)
+ break;
+
+ if (j == AD4170_NUM_CURRENT_SRC)
+ return dev_err_probe(&st->spi->dev, -EINVAL,
+ "Too many excitation current sources\n");
+
+ current_src |= FIELD_PREP(AD4170_CURRENT_SRC_I_OUT_PIN_MSK, pin);
+ current_src |= FIELD_PREP(AD4170_CURRENT_SRC_I_OUT_VAL_MSK, exc_cur);
+ st->cur_src_pins[j] = pin;
+ ret = regmap_write(st->regmap, AD4170_CURRENT_SRC_REG(j),
+ current_src);
+ if (ret)
+ return ret;
+ }
+
+ if (!ac_excited)
+ return 0;
+
+ if (num_exc_pins < 2)
+ return dev_err_probe(&st->spi->dev, -EINVAL,
+ "Current chopping requested but only one pin provided: %u\n",
+ exc_pins[0]);
+
+ /*
+ * Two use cases to handle here:
+ * - 2 pairs of excitation currents;
+ * - 1 pair of excitation currents.
+ */
+ if (num_exc_pins == 4) {
+ for (i = 0; i < AD4170_NUM_CURRENT_SRC; i++)
+ if (st->cur_src_pins[i] != exc_pins[i])
+ return dev_err_probe(&st->spi->dev, -EINVAL,
+ "Unable to use 4 exc pins\n");
+ } else {
+ /*
+ * Excitation current chopping is configured in pairs. Current
+ * sources IOUT0 and IOUT1 form pair 1, IOUT2 and IOUT3 make up
+ * pair 2. So, if current chopping was requested, check if the
+ * first end of the first pair of excitation currents is
+ * available. Try the next pair if IOUT0 has already been
+ * configured for another channel.
+ */
+ i = st->cur_src_pins[0] == exc_pins[0] ? 0 : 2;
+
+ if (st->cur_src_pins[i] != exc_pins[0] ||
+ st->cur_src_pins[i + 1] != exc_pins[1])
+ return dev_err_probe(&st->spi->dev, -EINVAL,
+ "Failed to setup current chopping\n");
+
+ st->cur_src_pins[i] = exc_pins[0];
+ st->cur_src_pins[i + 1] = exc_pins[1];
+
+ if (i == 0)
+ exc_cur_pair = AD4170_MISC_CHOP_IEXC_PAIR1;
+ else
+ exc_cur_pair = AD4170_MISC_CHOP_IEXC_PAIR2;
+ }
+
+ /*
+ * Configure excitation current chopping.
+ * Chop both pairs if using four excitation pins.
+ */
+ setup->misc |= FIELD_PREP(AD4170_MISC_CHOP_IEXC_MSK,
+ num_exc_pins == 2 ?
+ exc_cur_pair :
+ AD4170_MISC_CHOP_IEXC_BOTH);
+
+ return 0;
+}
+
+static int ad4170_setup_bridge(struct ad4170_state *st,
+ struct fwnode_handle *child,
+ struct ad4170_setup *setup, u32 *exc_pins,
+ unsigned int *exc_curs, int num_exc_pins,
+ bool ac_excited)
+{
+ unsigned long gpio_mask;
+ unsigned int i;
+ int ret;
+
+ /*
+ * If a specific current is provided through
+ * adi,excitation-current-n-microamp, set excitation pins provided
+ * through adi,excitation-pin-n to excite the bridge circuit.
+ */
+ for (i = 0; i < num_exc_pins; i++)
+ if (exc_curs[i] > 0)
+ return ad4170_setup_current_src(st, child, setup, exc_pins,
+ exc_curs, num_exc_pins,
+ ac_excited);
+
+ /*
+ * Else, use predefined ACX1, ACX1 negated, ACX2, ACX2 negated signals
+ * to AC excite the bridge. Those signals are output on GPIO2, GPIO0,
+ * GPIO3, and GPIO1, respectively. If only two pins are specified for AC
+ * excitation, use ACX1 and ACX2 (GPIO2 and GPIO3).
+ *
+ * Also, to avoid any short-circuit condition when more than one channel
+ * is enabled, set GPIO2 and GPIO0 high, and set GPIO1 and GPIO3 low to
+ * DC excite the bridge whenever a channel without AC excitation is
+ * selected. That is needed because GPIO pins are controlled by the next
+ * highest priority GPIO function when a channel doesn't enable AC
+ * excitation. See datasheet Figure 113 Weigh Scale (AC Excitation) for
+ * the reference circuit diagram.
+ */
+ if (num_exc_pins == 2) {
+ setup->misc |= FIELD_PREP(AD4170_MISC_CHOP_ADC_MSK, 0x3);
+
+ gpio_mask = AD4170_GPIO_MODE_GPIO3_MSK | AD4170_GPIO_MODE_GPIO2_MSK;
+ ret = regmap_update_bits(st->regmap, AD4170_GPIO_MODE_REG, gpio_mask,
+ FIELD_PREP(AD4170_GPIO_MODE_GPIO3_MSK,
+ AD4170_GPIO_MODE_GPIO_OUTPUT) |
+ FIELD_PREP(AD4170_GPIO_MODE_GPIO2_MSK,
+ AD4170_GPIO_MODE_GPIO_OUTPUT));
+ if (ret)
+ return ret;
+
+ /*
+ * Set GPIO2 high and GPIO3 low to DC excite the bridge when
+ * a different channel is selected.
+ */
+ gpio_mask = AD4170_GPIO_OUTPUT_GPIO_MSK(3) |
+ AD4170_GPIO_OUTPUT_GPIO_MSK(2);
+ ret = regmap_update_bits(st->regmap, AD4170_GPIO_OUTPUT_REG, gpio_mask,
+ FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(3), 0) |
+ FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(2), 1));
+ if (ret)
+ return ret;
+
+ st->gpio_fn[3] |= AD4170_GPIO_OUTPUT;
+ st->gpio_fn[2] |= AD4170_GPIO_OUTPUT;
+ } else {
+ setup->misc |= FIELD_PREP(AD4170_MISC_CHOP_ADC_MSK, 0x2);
+
+ gpio_mask = AD4170_GPIO_MODE_GPIO3_MSK | AD4170_GPIO_MODE_GPIO2_MSK |
+ AD4170_GPIO_MODE_GPIO1_MSK | AD4170_GPIO_MODE_GPIO0_MSK;
+ ret = regmap_update_bits(st->regmap, AD4170_GPIO_MODE_REG, gpio_mask,
+ FIELD_PREP(AD4170_GPIO_MODE_GPIO3_MSK,
+ AD4170_GPIO_MODE_GPIO_OUTPUT) |
+ FIELD_PREP(AD4170_GPIO_MODE_GPIO2_MSK,
+ AD4170_GPIO_MODE_GPIO_OUTPUT) |
+ FIELD_PREP(AD4170_GPIO_MODE_GPIO1_MSK,
+ AD4170_GPIO_MODE_GPIO_OUTPUT) |
+ FIELD_PREP(AD4170_GPIO_MODE_GPIO0_MSK,
+ AD4170_GPIO_MODE_GPIO_OUTPUT));
+ if (ret)
+ return ret;
+
+ /*
+ * Set GPIO2 and GPIO0 high, and set GPIO1 and GPIO3 low to DC
+ * excite the bridge when a different channel is selected.
+ */
+ gpio_mask = AD4170_GPIO_OUTPUT_GPIO_MSK(3) |
+ AD4170_GPIO_OUTPUT_GPIO_MSK(2) |
+ AD4170_GPIO_OUTPUT_GPIO_MSK(1) |
+ AD4170_GPIO_OUTPUT_GPIO_MSK(0);
+ ret = regmap_update_bits(st->regmap, AD4170_GPIO_OUTPUT_REG, gpio_mask,
+ FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(3), 0) |
+ FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(2), 1) |
+ FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(1), 0) |
+ FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(0), 1));
+ if (ret)
+ return ret;
+
+ st->gpio_fn[3] |= AD4170_GPIO_OUTPUT;
+ st->gpio_fn[2] |= AD4170_GPIO_OUTPUT;
+ st->gpio_fn[1] |= AD4170_GPIO_OUTPUT;
+ st->gpio_fn[0] |= AD4170_GPIO_OUTPUT;
+ }
+
+ return 0;
+}
+
+static int ad4170_setup_rtd(struct ad4170_state *st,
+ struct fwnode_handle *child,
+ struct ad4170_setup *setup, u32 *exc_pins,
+ unsigned int *exc_curs, int num_exc_pins, bool ac_excited)
+{
+ return ad4170_setup_current_src(st, child, setup, exc_pins,
+ exc_curs, num_exc_pins, ac_excited);
+}
+
+static int ad4170_parse_external_sensor(struct ad4170_state *st,
+ struct fwnode_handle *child,
+ struct ad4170_setup *setup,
+ struct iio_chan_spec *chan, u8 s_type)
+{
+ unsigned int num_exc_pins, reg_val;
+ struct device *dev = &st->spi->dev;
+ u32 pins[2], exc_pins[4], exc_curs[4];
+ bool ac_excited, vbias;
+ int ret;
+
+ ret = fwnode_property_read_u32_array(child, "diff-channels", pins,
+ ARRAY_SIZE(pins));
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to read sensor diff-channels\n");
+
+ chan->differential = true;
+ chan->channel = pins[0];
+ chan->channel2 = pins[1];
+
+ ret = ad4170_parse_exc_current(st, child, exc_pins, exc_curs, &num_exc_pins);
+ if (ret)
+ return ret;
+
+ /* The external sensor may not need excitation from the ADC chip. */
+ if (num_exc_pins == 0)
+ return 0;
+
+ ret = ad4170_validate_excitation_pins(st, exc_pins, num_exc_pins);
+ if (ret)
+ return ret;
+
+ ac_excited = fwnode_property_read_bool(child, "adi,excitation-ac");
+
+ if (s_type == AD4170_THERMOCOUPLE_SENSOR) {
+ vbias = fwnode_property_read_bool(child, "adi,vbias");
+ if (vbias) {
+ st->pins_fn[chan->channel2] |= AD4170_PIN_VBIAS;
+ reg_val = BIT(chan->channel2);
+ return regmap_write(st->regmap, AD4170_V_BIAS_REG,
+ reg_val);
+ }
+ }
+ if (s_type == AD4170_WEIGH_SCALE_SENSOR)
+ ret = ad4170_setup_bridge(st, child, setup, exc_pins, exc_curs,
+ num_exc_pins, ac_excited);
+ else
+ ret = ad4170_setup_rtd(st, child, setup, exc_pins, exc_curs,
+ num_exc_pins, ac_excited);
+
+ return ret;
+}
+
static int ad4170_parse_reference(struct ad4170_state *st,
struct fwnode_handle *child,
struct ad4170_setup *setup)
@@ -1803,8 +2268,9 @@ static int ad4170_parse_channel_node(struct iio_dev *indio_dev,
struct ad4170_chan_info *chan_info;
struct ad4170_setup *setup;
struct iio_chan_spec *chan;
+ unsigned int ref_select;
+ unsigned int s_type;
unsigned int ch_reg;
- u8 ref_select;
bool bipolar;
int ret;
@@ -1832,10 +2298,28 @@ static int ad4170_parse_channel_node(struct iio_dev *indio_dev,
if (ret)
return ret;
- ret = ad4170_parse_adc_channel_type(dev, child, chan);
- if (ret < 0)
- return ret;
+ ret = fwnode_property_match_property_string(child, "adi,sensor-type",
+ ad4170_sensor_type,
+ ARRAY_SIZE(ad4170_sensor_type));
+ /* Default to conventional ADC channel if sensor type not present */
+ s_type = ret < 0 ? AD4170_ADC_SENSOR : ret;
+ switch (s_type) {
+ case AD4170_ADC_SENSOR:
+ ret = ad4170_parse_adc_channel_type(dev, child, chan);
+ if (ret)
+ return ret;
+
+ break;
+ case AD4170_WEIGH_SCALE_SENSOR:
+ case AD4170_THERMOCOUPLE_SENSOR:
+ case AD4170_RTD_SENSOR:
+ ret = ad4170_parse_external_sensor(st, child, setup, chan, s_type);
+ if (ret)
+ return ret;
+
+ break;
+ }
bipolar = fwnode_property_read_bool(child, "bipolar");
setup->afe |= FIELD_PREP(AD4170_AFE_BIPOLAR_MSK, bipolar);
if (bipolar)
@@ -1843,11 +2327,11 @@ static int ad4170_parse_channel_node(struct iio_dev *indio_dev,
else
chan->scan_type.sign = 'u';
- ref_select = FIELD_GET(AD4170_AFE_REF_SELECT_MSK, setup->afe);
ret = ad4170_validate_channel(st, chan);
if (ret < 0)
return ret;
+ ref_select = FIELD_GET(AD4170_AFE_REF_SELECT_MSK, setup->afe);
ret = ad4170_get_input_range(st, chan, ch_reg, ref_select);
if (ret < 0)
return dev_err_probe(dev, ret, "Invalid input config\n");
@@ -2031,6 +2515,7 @@ static int ad4170_parse_firmware(struct iio_dev *indio_dev)
struct ad4170_state *st = iio_priv(indio_dev);
struct device *dev = &st->spi->dev;
int reg_data, ret;
+ unsigned int i;
ret = ad4170_clock_select(indio_dev);
if (ret)
@@ -2040,6 +2525,9 @@ static int ad4170_parse_firmware(struct iio_dev *indio_dev)
if (ret)
return ret;
+ for (i = 0; i < AD4170_NUM_CURRENT_SRC; i++)
+ st->cur_src_pins[i] = AD4170_CURRENT_SRC_DISABLED;
+
/* On power on, device defaults to using SDO pin for data ready signal */
st->int_pin_sel = AD4170_INT_PIN_SDO;
ret = device_property_match_property_string(dev, "interrupt-names",
--
2.47.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* Re: [PATCH v4 10/11] iio: adc: ad4170: Add support for weigh scale and RTD sensors
2025-06-02 11:40 ` [PATCH v4 10/11] iio: adc: ad4170: Add support for weigh scale and RTD sensors Marcelo Schmitt
@ 2025-06-07 17:15 ` Jonathan Cameron
0 siblings, 0 replies; 29+ messages in thread
From: Jonathan Cameron @ 2025-06-07 17:15 UTC (permalink / raw)
To: Marcelo Schmitt
Cc: linux-iio, devicetree, linux-gpio, linux-kernel, lars,
Michael.Hennerich, dlechner, nuno.sa, andy, robh, krzk+dt,
conor+dt, linus.walleij, brgl, marcelo.schmitt1
On Mon, 2 Jun 2025 08:40:01 -0300
Marcelo Schmitt <marcelo.schmitt@analog.com> wrote:
> The AD4170 design has features to aid interfacing with weigh scale and RTD
> sensors that are expected to be setup with external circuitry for proper
> sensor operation. A key characteristic of those sensors is that the circuit
> they are in must be excited with a pair of signals. The external circuit
> can be excited either by voltage supply or by AD4170 excitation signals.
> The sensor can then be read through a different pair of lines that are
> connected to AD4170 ADC.
>
> Configure AD4170 to handle external circuit sensors.
>
> Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
Trivial comments inline.
> +static int ad4170_validate_excitation_pins(struct ad4170_state *st,
> + u32 *exc_pins, int num_exc_pins)
> +{
> + unsigned int i;
> + int ret;
> +
> + for (i = 0; i < num_exc_pins; i++) {
> + unsigned int pin = exc_pins[i];
Is the local variable useful?
ret = ad4170_validate_excitation_pin(st, exc_pins[i]);
seems equally readable.
> +
> + ret = ad4170_validate_excitation_pin(st, pin);
> + if (ret)
> + return ret;
> + }
> + return 0;
> +}
>
> static int ad4170_parse_reference(struct ad4170_state *st,
> struct fwnode_handle *child,
> struct ad4170_setup *setup)
> @@ -1803,8 +2268,9 @@ static int ad4170_parse_channel_node(struct iio_dev *indio_dev,
> struct ad4170_chan_info *chan_info;
> struct ad4170_setup *setup;
> struct iio_chan_spec *chan;
> + unsigned int ref_select;
> + unsigned int s_type;
> unsigned int ch_reg;
> - u8 ref_select;
Why the change of type?
> bipolar = fwnode_property_read_bool(child, "bipolar");
> setup->afe |= FIELD_PREP(AD4170_AFE_BIPOLAR_MSK, bipolar);
> if (bipolar)
> @@ -1843,11 +2327,11 @@ static int ad4170_parse_channel_node(struct iio_dev *indio_dev,
> else
> chan->scan_type.sign = 'u';
>
> - ref_select = FIELD_GET(AD4170_AFE_REF_SELECT_MSK, setup->afe);
> ret = ad4170_validate_channel(st, chan);
> if (ret < 0)
> return ret;
>
> + ref_select = FIELD_GET(AD4170_AFE_REF_SELECT_MSK, setup->afe);
Can we do it in the patch that introduced the code rather than moving it here?
> ret = ad4170_get_input_range(st, chan, ch_reg, ref_select);
> if (ret < 0)
> return dev_err_probe(dev, ret, "Invalid input config\n");
^ permalink raw reply [flat|nested] 29+ messages in thread
* [PATCH v4 11/11] iio: adc: ad4170: Add timestamp channel
2025-06-02 11:34 [PATCH v4 00/11] iio: adc: Add support for AD4170 series of ADCs Marcelo Schmitt
` (9 preceding siblings ...)
2025-06-02 11:40 ` [PATCH v4 10/11] iio: adc: ad4170: Add support for weigh scale and RTD sensors Marcelo Schmitt
@ 2025-06-02 11:40 ` Marcelo Schmitt
10 siblings, 0 replies; 29+ messages in thread
From: Marcelo Schmitt @ 2025-06-02 11:40 UTC (permalink / raw)
To: linux-iio, devicetree, linux-gpio, linux-kernel
Cc: jic23, lars, Michael.Hennerich, dlechner, nuno.sa, andy, robh,
krzk+dt, conor+dt, linus.walleij, brgl, marcelo.schmitt1
Add timestamp channel allowing to record the moment at which ADC samples
are captured in buffered read mode.
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
---
drivers/iio/adc/ad4170.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/drivers/iio/adc/ad4170.c b/drivers/iio/adc/ad4170.c
index 23b634d324a7..28466b245567 100644
--- a/drivers/iio/adc/ad4170.c
+++ b/drivers/iio/adc/ad4170.c
@@ -182,6 +182,7 @@
#define AD4170_NUM_ANALOG_PINS 9
#define AD4170_NUM_GPIO_PINS 4
#define AD4170_MAX_CHANNELS 16
+#define AD4170_MAX_IIO_CHANNELS (AD4170_MAX_CHANNELS + 1)
#define AD4170_MAX_ANALOG_PINS 8
#define AD4170_MAX_SETUPS 8
#define AD4170_INVALID_SETUP 9
@@ -426,7 +427,7 @@ struct ad4170_state {
int vrefs_uv[AD4170_MAX_SUP];
u32 mclk_hz;
struct ad4170_setup_info setup_infos[AD4170_MAX_SETUPS];
- struct iio_chan_spec chans[AD4170_MAX_CHANNELS];
+ struct iio_chan_spec chans[AD4170_MAX_IIO_CHANNELS];
struct ad4170_chan_info chan_infos[AD4170_MAX_CHANNELS];
struct spi_device *spi;
struct regmap *regmap;
@@ -443,6 +444,7 @@ struct ad4170_state {
unsigned int clock_ctrl;
int gpio_fn[AD4170_NUM_GPIO_PINS];
unsigned int cur_src_pins[AD4170_NUM_CURRENT_SRC];
+ unsigned int num_adc_chans;
/*
* DMA (thus cache coherency maintenance) requires the transfer buffers
* to live in their own cache lines.
@@ -2385,7 +2387,16 @@ static int ad4170_parse_channels(struct iio_dev *indio_dev)
return dev_err_probe(dev, ret, "Invalid input config\n");
st->chan_infos[chan_num].input_range_uv = ret;
+ chan_num++;
}
+ st->num_adc_chans = chan_num;
+
+ /* Add timestamp channel */
+ struct iio_chan_spec ts_chan = IIO_CHAN_SOFT_TIMESTAMP(chan_num);
+
+ st->chans[chan_num] = ts_chan;
+ num_channels = num_channels + 1;
+
indio_dev->num_channels = num_channels;
indio_dev->channels = st->chans;
@@ -2577,7 +2588,7 @@ static int ad4170_initial_config(struct iio_dev *indio_dev)
return dev_err_probe(dev, ret,
"Failed to set ADC mode to idle\n");
- for (i = 0; i < indio_dev->num_channels; i++) {
+ for (i = 0; i < st->num_adc_chans; i++) {
struct ad4170_chan_info *chan_info;
struct iio_chan_spec const *chan;
struct ad4170_setup *setup;
@@ -2702,7 +2713,7 @@ static int ad4170_buffer_predisable(struct iio_dev *indio_dev)
* is done after buffer disable. Disable all channels so only requested
* channels will be read.
*/
- for (i = 0; i < indio_dev->num_channels; i++) {
+ for (i = 0; i < st->num_adc_chans; i++) {
ret = ad4170_set_channel_enable(st, i, false);
if (ret)
return ret;
@@ -2752,7 +2763,9 @@ static irqreturn_t ad4170_trigger_handler(int irq, void *p)
memcpy(&st->bounce_buffer[i++], st->rx_buf, ARRAY_SIZE(st->rx_buf));
}
- iio_push_to_buffers(indio_dev, st->bounce_buffer);
+ iio_push_to_buffers_with_ts(indio_dev, st->bounce_buffer,
+ sizeof(st->bounce_buffer),
+ iio_get_time_ns(indio_dev));
err_out:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
--
2.47.2
^ permalink raw reply related [flat|nested] 29+ messages in thread