On Tue, 10 Jun 2025 09:34:35 +0200
Jorge Marques <jorge.marques@xxxxxxxxxx> wrote:
> Add dt-bindings for AD4052 family, devices AD4050/AD4052/AD4056/AD4058,
> low-power with monitor capabilities SAR ADCs. Each variant of the family
> differs in speed and resolution, resulting in different scan types and
> spi word sizes, that are matched by the compatible with the chip_info.
The bit about what the drive does with this doesn't really belong in a DT
binding patch description. Stick to just something like.
Each variant of the family differs in speed and resolution, reflected
in word size for SPI messages.
> The device contains one input (cnv) and two outputs (gp0, gp1).
> The outputs can be configured for range of options, such as threshold
> and data ready.
> The spi-max-frequency refers to the configuration mode maximum access
> speed. The ADC mode speed depends on the vio input voltage.
>
> Signed-off-by: Jorge Marques <jorge.marques@xxxxxxxxxx>
> ---
> .../devicetree/bindings/iio/adc/adi,ad4052.yaml | 167 +++++++++++++++++++++
> MAINTAINERS | 6 +
> include/dt-bindings/iio/adc/adi,ad4052.h | 17 +++
> 3 files changed, 190 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad4052.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad4052.yaml
> new file mode 100644
> index 0000000000000000000000000000000000000000..2cf197e2d872d9a3d4f7210121a1e38f784f92dc
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad4052.yaml
> @@ -0,0 +1,167 @@
> +
> + interrupts:
> + items:
> + - description: Signal coming from the GP0 pin.
Description would be better in interrupt-names than here.
> + - description: Signal coming from the GP1 pin.
Also minItems should be specified to allow for just one of these
being wired I think.
> +
> + interrupt-names:
> + items:
> + - const: gp0
> + - const: gp1
> +
> + cnv-gpios:
> + description: The Convert Input (CNV). If omitted, CNV is tied to SPI CS.
> + maxItems: 1
> +
> + pwms:
> + maxItems: 1
> + description: PWM connected to the CNV pin.
> +
> + trigger-sources:
> + minItems: 1
> + maxItems: 2
> + description:
> + Describes the output pin and event associated.
> +
> + "#trigger-source-cells":
> + const: 2
> + description: |
> + Output pins used as trigger source.
> +
> + Cell 0 defines the event:
> + * 0 = Data ready
> + * 1 = Min threshold
> + * 2 = Max threshold
> + * 3 = Either threshold
> + * 4 = CHOP control
> + * 5 = Device enable
> + * 6 = Device ready (only GP1)
Hmm. I'm a bit dubious on why 'what the offload trigger is'
is a DT thing? Is that because the IP needs to comprehend
this? I guess only data ready is actually supported in
practice?
What would the use of Device enable or device ready or chop
control actually be?
The thresholds are unusual but those I can sort of understand.
Jonathan
> +
> + Cell 1 defines which pin:
> + * 0 = GP0
> + * 1 = GP1
> +
> + For convenience, macros for these values are available in
> + dt-bindings/iio/adc/adi,ad4052.h.
> +
> + spi-max-frequency:
> + maximum: 83333333
> +
> + vdd-supply:
> + description: Analog power supply.
> +
> + vio-supply:
> + description: Digital interface logic power supply.
> +
> + ref-supply:
> + description: |
Don't need the | as no need to preserve anything about formatting of
a single paragraph like this.
> + Reference voltage to set the ADC full-scale range. If not present,
> + vdd-supply is used as the reference voltage.
> +
> +required:
> + - compatible
> + - reg
> + - vdd-supply
> + - vio-supply
> +
> +allOf:
> + - $ref: /schemas/spi/spi-peripheral-props.yaml#
> +
> +unevaluatedProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/gpio/gpio.h>
> + #include <dt-bindings/interrupt-controller/irq.h>
> + #include <dt-bindings/iio/adc/adi,ad4052.h>
> +
> + spi {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + adc@0 {
> + compatible = "adi,ad4052";
> + reg = <0>;
> + vdd-supply = <&vdd>;
> + vio-supply = <&vio>;
> + ref-supply = <&ref>;
> + spi-max-frequency = <83333333>;
> +
> + #trigger-source-cells = <2>;
> + trigger-sources = <&adc AD4052_TRIGGER_EVENT_EITHER_THRESH
> + AD4052_TRIGGER_PIN_GP0
> + &adc AD4052_TRIGGER_EVENT_DATA_READY
> + AD4052_TRIGGER_PIN_GP1>;
> + interrupt-parent = <&gpio>;
> + interrupts = <0 0 IRQ_TYPE_EDGE_RISING>,
> + <0 1 IRQ_TYPE_EDGE_FALLING>;
> + interrupt-names = "gp0", "gp1";
> + cnv-gpios = <&gpio 2 GPIO_ACTIVE_HIGH>;
> + };
> + };
> + - |
> + #include <dt-bindings/gpio/gpio.h>
> + #include <dt-bindings/interrupt-controller/irq.h>
> + #include <dt-bindings/iio/adc/adi,ad4052.h>
> +
> + rx_dma {
> + #dma-cells = <1>;
> + };
> +
> + spi {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + dmas = <&rx_dma 0>;
> + dma-names = "offload0-rx";
> + trigger-sources = <&adc AD4052_TRIGGER_EVENT_DATA_READY
> + AD4052_TRIGGER_PIN_GP1>;
> +
> + adc@0 {
> + compatible = "adi,ad4052";
> + reg = <0>;
> + vdd-supply = <&vdd>;
> + vio-supply = <&vio>;
> + spi-max-frequency = <83333333>;
> + pwms = <&adc_trigger 0 10000 0>;
> +
> + #trigger-source-cells = <2>;
> + trigger-sources = <&adc AD4052_TRIGGER_EVENT_EITHER_THRESH
> + AD4052_TRIGGER_PIN_GP0
> + &adc AD4052_TRIGGER_EVENT_DATA_READY
> + AD4052_TRIGGER_PIN_GP1>;
> + interrupt-parent = <&gpio>;
> + interrupts = <0 0 IRQ_TYPE_EDGE_RISING>,
> + <0 1 IRQ_TYPE_EDGE_FALLING>;
> + interrupt-names = "gp0", "gp1";
> + cnv-gpios = <&gpio 2 GPIO_ACTIVE_HIGH>;
> + };
> + };
> diff --git a/MAINTAINERS b/MAINTAINERS
> index c02d83560058f7ea75e24509b4d87ef293df6773..d000c7de7ff9eba390f87593bc2b1847f966f48b 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1337,6 +1337,12 @@ F: Documentation/devicetree/bindings/iio/adc/adi,ad4030.yaml
> F: Documentation/iio/ad4030.rst
> F: drivers/iio/adc/ad4030.c
>
> +ANALOG DEVICES INC AD4052 DRIVER
> +M: Jorge Marques <jorge.marques@xxxxxxxxxx>
> +S: Supported
> +W: https://ez.analog.com/linux-software-drivers
> +F: Documentation/devicetree/bindings/iio/adc/adi,ad4052.yaml
> +
> ANALOG DEVICES INC AD4080 DRIVER
> M: Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx>
> L: linux-iio@xxxxxxxxxxxxxxx
> diff --git a/include/dt-bindings/iio/adc/adi,ad4052.h b/include/dt-bindings/iio/adc/adi,ad4052.h
> new file mode 100644
> index 0000000000000000000000000000000000000000..37db5d9d10e788d5e7fb715c4ba9077e555131d5
> --- /dev/null
> +++ b/include/dt-bindings/iio/adc/adi,ad4052.h
> @@ -0,0 +1,17 @@
> +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
> +
> +#ifndef _DT_BINDINGS_ADI_AD4052_H
> +#define _DT_BINDINGS_ADI_AD4052_H
> +
> +#define AD4052_TRIGGER_EVENT_DATA_READY 0
> +#define AD4052_TRIGGER_EVENT_MIN_THRESH 1
> +#define AD4052_TRIGGER_EVENT_MAX_THRESH 2
> +#define AD4052_TRIGGER_EVENT_EITHER_THRESH 3
> +#define AD4052_TRIGGER_EVENT_CHOP 4
> +#define AD4052_TRIGGER_EVENT_DEV_ENABLED 5
> +#define AD4052_TRIGGER_EVENT_DEV_READY 6
> +
> +#define AD4052_TRIGGER_PIN_GP0 0
> +#define AD4052_TRIGGER_PIN_GP1 1
> +
> +#endif /* _DT_BINDINGS_ADI_AD4052_H */
>
