Subject: Re: [V6, 1/2] media: dt-bindings: media: i2c: Document DW9768 bindings

From: Rob Herring <[email-masked]>
Date: Mon, 18 May 2020 08:31:48 -0600

On Mon, May 18, 2020 at 04:12:28PM +0200, Tomasz Figa wrote:
> Hi Dongchun,
> 
> On Mon, May 18, 2020 at 3:29 PM Dongchun Zhu <[email-masked]> wrote:
> >
> > Add DeviceTree binding documentation for Dongwoon Anatech DW9768 voice
> > coil actuator.
> 
> Thanks for the patch. Please see my comments below.
> 
> >
> > Signed-off-by: Dongchun Zhu <[email-masked]>
> > Reviewed-by: Rob Herring <[email-masked]>
> 
> This version includes significant changes, so the reviewed-by tag
> shouldn't have been carried out.
> 
> > ---
> >  .../bindings/media/i2c/dongwoon,dw9768.yaml        | 105 +++++++++++++++++++++
> >  MAINTAINERS                                        |   7 ++
> >  2 files changed, 112 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/media/i2c/dongwoon,dw9768.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/media/i2c/dongwoon,dw9768.yaml b/Documentation/devicetree/bindings/media/i2c/dongwoon,dw9768.yaml
> > new file mode 100644
> > index 0000000..b909e83
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/media/i2c/dongwoon,dw9768.yaml
> > @@ -0,0 +1,105 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +# Copyright (c) 2020 MediaTek Inc.
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/media/i2c/dongwoon,dw9768.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Dongwoon Anatech DW9768 Voice Coil Motor (VCM) Lens Device Tree Bindings
> > +
> > +maintainers:
> > +  - Dongchun Zhu <[email-masked]>
> > +
> > +description: |-
> > +  The Dongwoon DW9768 is a single 10-bit digital-to-analog (DAC) converter
> > +  with 100 mA output current sink capability. VCM current is controlled with
> > +  a linear mode driver. The DAC is controlled via a 2-wire (I2C-compatible)
> > +  serial interface that operates at clock rates up to 1MHz. This chip
> > +  integrates Advanced Actuator Control (AAC) technology and is intended for
> > +  driving voice coil lenses in camera modules.
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      # for DW9768 VCM
> > +      - dongwoon,dw9768
> > +      # for GT9769 VCM
> > +      - giantec,gt9769
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  vin-supply:
> > +    description:
> > +      Definition of the regulator used as I2C I/O interface power supply.
> > +
> > +  vdd-supply:
> > +    description:
> > +      Definition of the regulator used as VCM chip power supply.
> > +
> > +  dongwoon,aac-mode:
> > +    description:
> > +      Indication of AAC mode select.
> > +    allOf:
> > +      - $ref: "/schemas/types.yaml#/definitions/uint32"
> > +      - enum:
> > +          - 0    #  Direct (default)

Default can be expressed as 'default: 0'.

> > +          - 1    #  AAC2 (operation time# 0.48 x Tvib)
> > +          - 2    #  AAC3 (operation time# 0.70 x Tvib)
> > +          - 3    #  AAC4 (operation time# 0.75 x Tvib)
> > +          - 4    #  Reserved
> > +          - 5    #  AAC8 (operation time# 1.13 x Tvib)
> > +          - 6    #  Reserved
> > +          - 7    #  Reserved
> 
> I'll ultimately leave it to DT maintainers, but is there any reason to
> define the reserved values?

No.

> 
> > +
> > +  dongwoon,aac-timing:
> > +    description:
> > +      Indication of AAC Timing count, unit of 0.1 milliseconds.

Why not just use standard units (-us)?

> > +      Valid values vary from 0 to 63 (default 32).

Looks like constraints.

> > +    allOf:
> > +      - $ref: "/schemas/types.yaml#/definitions/uint32"
> > +
> > +  dongwoon,clock-dividing-rate:
> > +    description:
> > +      Indication of VCM internal clock dividing rate select, as one multiple
> > +      factor to calculate VCM ring periodic time Tvib.
> > +    allOf:
> > +      - $ref: "/schemas/types.yaml#/definitions/uint32"
> > +      - enum:
> > +          - 0    #  Dividing Rate -  2
> > +          - 1    #  Dividing Rate -  1 (default)
> > +          - 2    #  Dividing Rate -  1/2
> > +          - 3    #  Dividing Rate -  1/4
> > +          - 4    #  Dividing Rate -  8
> > +          - 5    #  Dividing Rate -  4
> > +          - 6    #  Dividing Rate -  Reserved
> > +          - 7    #  Dividing Rate -  Reserved
> 
> Ditto.
> 
> Best regards,
> Tomasz

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