Re: [V8, 1/2] media: dt-bindings: media: i2c: Document OV02A10 bindings

[Dongchun Zhu <dongchun.zhu@mediatek.com>]

Hi Tomasz, Rob,

On Thu, 2020-05-21 at 19:35 +0000, Tomasz Figa wrote:
> Hi Rob,
> 
> On Mon, May 11, 2020 at 11:02:07AM -0500, Rob Herring wrote:
> > On Sat, May 09, 2020 at 04:06:26PM +0800, Dongchun Zhu wrote:
> > > Add DT bindings documentation for Omnivision OV02A10 image sensor.
> > > 
> > > Signed-off-by: Dongchun Zhu <dongchun.zhu@mediatek.com>
> > > ---
> > >  .../bindings/media/i2c/ovti,ov02a10.yaml           | 184 +++++++++++++++++++++
> > >  MAINTAINERS                                        |   7 +
> > >  2 files changed, 191 insertions(+)
> > >  create mode 100644 Documentation/devicetree/bindings/media/i2c/ovti,ov02a10.yaml
> > > 
> > > diff --git a/Documentation/devicetree/bindings/media/i2c/ovti,ov02a10.yaml b/Documentation/devicetree/bindings/media/i2c/ovti,ov02a10.yaml
> > > new file mode 100644
> > > index 0000000..5468d1b
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/media/i2c/ovti,ov02a10.yaml
> > > @@ -0,0 +1,184 @@
> > > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > > +# Copyright (c) 2020 MediaTek Inc.
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/media/i2c/ovti,ov02a10.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: Omnivision OV02A10 CMOS Sensor Device Tree Bindings
> > > +
> > > +maintainers:
> > > +  - Dongchun Zhu <dongchun.zhu@mediatek.com>
> > > +
> > > +description: |-
> > > +  The Omnivision OV02A10 is a low-cost, high performance, 1/5-inch, 2 megapixel
> > > +  image sensor, which is the latest production derived from Omnivision's CMOS
> > > +  image sensor technology. Ihis chip supports high frame rate speeds up to 30fps
> > > +  @ 1600x1200 (UXGA) resolution transferred over a 1-lane MIPI interface. The
> > > +  sensor output is available via CSI-2 serial data output.
> > > +
> > > +properties:
> > > +  compatible:
> > > +    const: ovti,ov02a10
> > > +
> > > +  reg:
> > > +    description: I2C device address
> > 
> > Drop this. Nothing specific to this device.
> > 
> > > +    maxItems: 1
> > > +
> > > +  clocks:
> > > +    items:
> > > +      - description: top mux camtg clock
> > > +      - description: devider clock
> > 
> > typo
> > 
> > > +
> > > +  clock-names:
> > > +    items:
> > > +      - const: eclk
> > > +      - const: freq_mux
> > > +
> > > +  clock-frequency:
> > > +    description:
> > > +      Frequency of the eclk clock in Hertz.
> > > +
> > > +  dovdd-supply:
> > > +    description:
> > > +      Definition of the regulator used as interface power supply.
> > > +
> > > +  avdd-supply:
> > > +    description:
> > > +      Definition of the regulator used as analog power supply.
> > > +
> > > +  dvdd-supply:
> > > +    description:
> > > +      Definition of the regulator used as digital power supply.
> > > +
> > > +  powerdown-gpios:
> > > +    maxItems: 1
> > > +
> > > +  reset-gpios:
> > > +    maxItems: 1
> 
> I asked a question about defining GPIO polarities some time ago, but I
> guess it slipped through.
> 
> The chip documentation calls the reset pin as "RST_PAD (low level
> reset)". Where should the inversion be handled, in the driver or here,
> by having the DT include a necessary flag in the specifier?
> 
> Best regards,
> Tomasz

For powerdown-gpios and reset-gpios, I actually defined two totally
different GPIO polarities in DT according to OV02A10 chip documentation.
One is GPIO_ACTIVE_LOW, the other is GPIO_ACTIVE_HIGH (see examples
below).

So I'm wondering if we could add such one polarity-flag that Tomasz
suggested.