Re: [PATCH 1/8] ASoC: rockchip: rk3308: add internal audio codec bindings

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 07/09/2022 16:21, luca.ceresoli@bootlin.com wrote:
> From: Luca Ceresoli <luca.ceresoli@bootlin.com>
> 
> Add device tree bindings document for the internal audio codec of the
> Rockchip RK3308 SoC.
> 
> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

Use subject prefixes matching the subsystem (git log --oneline -- ...).

> ---
>  .../bindings/sound/rockchip,rk3308-codec.yaml | 102 ++++++++++++++++++
>  MAINTAINERS                                   |   6 ++
>  .../dt-bindings/sound/rockchip,rk3308-codec.h |  15 +++
>  3 files changed, 123 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/sound/rockchip,rk3308-codec.yaml
>  create mode 100644 include/dt-bindings/sound/rockchip,rk3308-codec.h
> 
> diff --git a/Documentation/devicetree/bindings/sound/rockchip,rk3308-codec.yaml b/Documentation/devicetree/bindings/sound/rockchip,rk3308-codec.yaml
> new file mode 100644
> index 000000000000..f3458f86ef06
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/sound/rockchip,rk3308-codec.yaml
> @@ -0,0 +1,102 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/sound/rockchip,rk3308-codec.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Rockchip RK3308 Internal Codec
> +
> +description: |
> +  This is the audio codec embedded in the Rockchip RK3308
> +  SoC. It has 8 24-bit ADCs and 2 24-bit DACs. The maximum supported
> +  sampling rate is 192 kHz.
> +
> +  It is connected internally to one out of a selection of the internal I2S
> +  controllers.
> +
> +  The RK3308 audio codec has 8 independent capture channels, but some
> +  features work on stereo pairs called groups:
> +    * grp 0 -- MIC1 / MIC2
> +    * grp 1 -- MIC3 / MIC4
> +    * grp 2 -- MIC5 / MIC6
> +    * grp 3 -- MIC7 / MIC8
> +
> +maintainers:
> +  - Luca Ceresoli <luca.ceresoli@bootlin.com>
> +
> +properties:
> +  compatible:
> +    const: rockchip,rk3308-codec
> +
> +  reg:
> +    maxItems: 1
> +
> +  rockchip,grf:
> +    $ref: /schemas/types.yaml#/definitions/phandle
> +    description:
> +      Phandle to the General Register Files (GRF)
> +
> +  clocks:
> +    items:
> +      - description: clock for TX
> +      - description: clock for RX
> +      - description: AHB clock driving the interface
> +
> +  clock-names:
> +    items:
> +      - const: mclk_tx
> +      - const: mclk_rx
> +      - const: hclk
> +
> +  resets: true

maxItems: 1

> +
> +  reset-names:
> +    items:
> +      - const: "acodec"

No quotes.

> +
> +  "#sound-dai-cells":
> +    const: 0
> +
> +  rockchip,micbias-avdd-multiplier:
> +    description: |
> +      Voltage setting for the MICBIAS pins expressed as a multiplier of
> +      AVDD.
> +
> +      E.g. if rockchip,micbias-avdd-multiplier = 7 (x0.85) and AVDD = 3v3,
> +      then MIC BIAS voltage will be 3.3 V * 0.85 = 2.805 V.
> +
> +      Value 0: multiplier = 0.50
> +      Value N: multiplier = 0.50 + 0.05 * N
> +      Value 7: multiplier = 0.85

Use logical values/units. The units is 0.05, so "-percent" in node name.
https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/property-units.yaml
Then drop ref and use enum.

> +
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    maximum: 7
> +
> +required:
> +  - compatible
> +  - reg
> +  - rockchip,grf
> +  - clocks
> +  - resets
> +  - "#sound-dai-cells"
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/rk3308-cru.h>
> +
> +    acodec: acodec@ff560000 {

codec

Node names should be generic.
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation

> +        compatible = "rockchip,rk3308-codec";
> +        reg = <0xff560000 0x10000>;
> +        rockchip,grf = <&grf>;
> +        clock-names = "mclk_tx", "mclk_rx", "hclk";
> +        clocks = <&cru SCLK_I2S2_8CH_TX_OUT>,
> +                 <&cru SCLK_I2S2_8CH_RX_OUT>,
> +                 <&cru PCLK_ACODEC>;
> +        reset-names = "acodec";
> +        resets = <&cru SRST_ACODEC_P>;
> +        #sound-dai-cells = <0>;
> +    };
> +
> +...
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 895e8ace80dd..d53a8e74cb1e 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -17588,6 +17588,12 @@ S:	Maintained
>  F:	Documentation/devicetree/bindings/media/rockchip-rga.yaml
>  F:	drivers/media/platform/rockchip/rga/
>  
> +ROCKCHIP RK3308 INTERNAL AUDIO CODEC
> +M:	Luca Ceresoli <luca.ceresoli@bootlin.com>
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/sound/rockchip,rk3308-codec.yaml
> +F:	include/dt-bindings/sound/rockchip,rk3308-codec.h
> +
>  ROCKCHIP VIDEO DECODER DRIVER
>  M:	Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
>  L:	linux-media@vger.kernel.org
> diff --git a/include/dt-bindings/sound/rockchip,rk3308-codec.h b/include/dt-bindings/sound/rockchip,rk3308-codec.h
> new file mode 100644
> index 000000000000..9f1b210a048e
> --- /dev/null
> +++ b/include/dt-bindings/sound/rockchip,rk3308-codec.h
> @@ -0,0 +1,15 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */

Dual license.

> +#ifndef __DT_BINDINGS_ROCKCHIP_RK3308_CODEC_H__
> +#define __DT_BINDINGS_ROCKCHIP_RK3308_CODEC_H__
> +
> +#define RK3308_CODEC_MICBIAS_AVDD_x_0_50	0
> +#define RK3308_CODEC_MICBIAS_AVDD_x_0_55	1
> +#define RK3308_CODEC_MICBIAS_AVDD_x_0_60	2
> +#define RK3308_CODEC_MICBIAS_AVDD_x_0_65	3
> +#define RK3308_CODEC_MICBIAS_AVDD_x_0_70	4
> +#define RK3308_CODEC_MICBIAS_AVDD_x_0_75	5
> +#define RK3308_CODEC_MICBIAS_AVDD_x_0_80	6
> +#define RK3308_CODEC_MICBIAS_AVDD_x_0_85	7

You store register values in the bindings. Nope. Bindings are not for this.

Best regards,
Krzysztof