Re: [PATCH 03/10] dt-bindings: iio: frequency: add adi,ad9910-axi-backend

From: Conor Dooley

Date: Thu Oct 15 2026 - 15:00:15 EST


On Thu, Oct 15, 2026 at 01:49:43PM -0300, Rodrigo Alencar via B4 Relay wrote:
> From: Rodrigo Alencar <rodrigo.alencar@xxxxxxxxxx>
>
> Add bindings for the AD9910 AXI backend IP core. The FPGA IP core
> interfaces with the data and control pins of the AD9910 DDS, streaming
> data from memory via DMA into the 18-bit parallel data port (F[1:0] and
> D[15:0] pins), which is clocked by the PDCLK output of the device. It
> also drives the PROFILE[2:0] pins and the DRCTL pin, which controls the
> slope direction of the digital ramp generator (DRG). The DRCTL pin is
> driven by a PWM generator, so the IP core is described both as an IIO
> backend and as a PWM provider.
>
> Signed-off-by: Rodrigo Alencar <rodrigo.alencar@xxxxxxxxxx>
> ---
> .../iio/frequency/adi,ad9910-axi-backend.yaml | 74 ++++++++++++++++++++++
> MAINTAINERS | 1 +
> 2 files changed, 75 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/iio/frequency/adi,ad9910-axi-backend.yaml b/Documentation/devicetree/bindings/iio/frequency/adi,ad9910-axi-backend.yaml
> new file mode 100644
> index 000000000000..20b884e8eb10
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/frequency/adi,ad9910-axi-backend.yaml
> @@ -0,0 +1,74 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/frequency/adi,ad9910-axi-backend.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Analog Devices AD9910 AXI Backend IP core
> +
> +maintainers:
> + - Rodrigo Alencar <rodrigo.alencar@xxxxxxxxxx>
> +
> +description:
> + FPGA IP core that interfaces with the data and control pins of the AD9910
> + Direct Digital Synthesizer. The SPI bus is used as the control interface
> + of the AD9910 device, while this IP core streams data from memory via DMA
> + into the 18-bit parallel data port (F[1:0] and D[15:0] pins), which is
> + clocked by the PDCLK output of the AD9910. The IP core also drives the
> + PROFILE[2:0] pins for profile selection and provides a PWM generator that
> + drives the DRCTL pin, controlling the digital ramp generator (DRG) slope
> + direction.
> +
> + https://www.analog.com/en/products/ad9910.html

Should this link not point to the docs for the backend device?

Otherwise, this is pretty fine I think..

Conor.

> +
> +properties:
> + compatible:
> + const: adi,ad9910-axi-backend
> +
> + reg:
> + maxItems: 1
> +
> + clocks:
> + maxItems: 1
> + description: AXI bus clock (s_axi_aclk).
> +
> + dmas:
> + maxItems: 1
> +
> + dma-names:
> + items:
> + - const: tx
> +
> + '#io-backend-cells':
> + const: 0
> +
> + '#pwm-cells':
> + const: 3
> + description:
> + The first cell must be 0, as only the DRCTL PWM output is available.
> + The second cell is the PWM period in nanoseconds and the third cell
> + holds the PWM flags.
> +
> +required:
> + - compatible
> + - reg
> + - clocks
> + - dmas
> + - dma-names
> + - '#io-backend-cells'
> + - '#pwm-cells'
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + ad9910_backend: dds-backend@44a00000 {
> + compatible = "adi,ad9910-axi-backend";
> + reg = <0x44a00000 0x10000>;
> + clocks = <&clkc 15>;
> + dmas = <&tx_dma 0>;
> + dma-names = "tx";
> + #io-backend-cells = <0>;
> + #pwm-cells = <3>;
> + };
> +...
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 3a2dfd1a4fd8..93ad6a829cb3 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1731,6 +1731,7 @@ S: Supported
> W: https://ez.analog.com/linux-software-drivers
> F: Documentation/ABI/testing/debugfs-iio-ad9910
> F: Documentation/ABI/testing/sysfs-bus-iio-frequency-ad9910
> +F: Documentation/devicetree/bindings/iio/frequency/adi,ad9910-axi-backend.yaml
> F: Documentation/devicetree/bindings/iio/frequency/adi,ad9910.yaml
> F: Documentation/iio/ad9910.rst
> F: drivers/iio/frequency/ad9910.c
>
> --
> 2.43.0
>
>

Attachment: signature.asc
Description: PGP signature