Re: [PATCH v3] dt-bindings: mfd: rk808: Convert bindings to yaml

[Rob Herring <robh@kernel.org>]

On Wed, Feb 16, 2022 at 12:39:09PM +0000, Robin Murphy wrote:
> On 2022-02-15 21:15, Chris Morgan wrote:
> [...]
> > diff --git a/Documentation/devicetree/bindings/mfd/rockchip,rk805.yaml b/Documentation/devicetree/bindings/mfd/rockchip,rk805.yaml
> > new file mode 100644
> > index 000000000000..1b928b94fbfd
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mfd/rockchip,rk805.yaml
> > @@ -0,0 +1,88 @@
> > +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/mfd/rockchip,rk805.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: RK805 Power Management Integrated Circuit
> > +
> > +maintainers:
> > +  - Chris Zhong <zyw@rock-chips.com>
> > +  - Zhang Qing <zhangqing@rock-chips.com>
> > +
> > +description: |
> > +  Rockchip RK805 series PMIC. This device consists of an i2c controlled MFD
> > +  that includes multiple switchable regulators.
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - rockchip,rk805
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +  '#clock-cells':
> > +    const: 1
> > +
> > +  clock-output-names:
> > +    maxItems: 2
> 
> I think this should be 1, since RK805 only has a single CLK32K output -
> ditto for RK817.
> 
> [...]
> > diff --git a/Documentation/devicetree/bindings/mfd/rockchip,rk808.yaml b/Documentation/devicetree/bindings/mfd/rockchip,rk808.yaml
> > new file mode 100644
> > index 000000000000..f5908fa01a61
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mfd/rockchip,rk808.yaml
> > @@ -0,0 +1,257 @@
> > +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/mfd/rockchip,rk808.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: RK808 Power Management Integrated Circuit
> > +
> > +maintainers:
> > +  - Chris Zhong <zyw@rock-chips.com>
> > +  - Zhang Qing <zhangqing@rock-chips.com>
> > +
> > +description: |
> > +  Rockchip RK808 series PMIC. This device consists of an i2c controlled MFD
> > +  that includes regulators, an RTC, and a power button.
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - rockchip,rk808
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +  '#clock-cells':
> > +    description:
> > +      See <dt-bindings/clock/rockchip,rk808.h> for clock IDs.
> > +    const: 1
> > +
> > +  clock-output-names:
> > +    description:
> > +      From common clock binding to override the default output clock name.
> 
> minItems should be consistent across RK808/818/819 - when two clocks exist,
> either it's legitimate to rename only the first one, or it isn't. There
> shouldn't be an arbitrary difference just because of what existing DTs
> happen to use.
> 
> > +    maxItems: 2
> > +
> > +  rockchip,system-power-controller:
> > +    type: boolean
> > +    description:
> > +      Telling whether or not this PMIC is controlling the system power.
> > +
> > +  wakeup-source:
> > +    type: boolean
> > +    description:
> > +      Device can be used as a wakeup source.
> > +
> > +  vcc1-supply:
> > +    description:
> > +      The input supply for DCDC_REG1.
> > +
> > +  vcc2-supply:
> > +    description:
> > +      The input supply for DCDC_REG2.
> > +
> > +  vcc3-supply:
> > +    description:
> > +      The input supply for DCDC_REG3.
> > +
> > +  vcc4-supply:
> > +    description:
> > +      The input supply for DCDC_REG4.
> > +
> > +  vcc6-supply:
> > +    description:
> > +      The input supply for LDO_REG1 and LDO_REG2.
> > +
> > +  vcc7-supply:
> > +    description:
> > +      The input supply for LDO_REG3 and LDO_REG7.
> > +
> > +  vcc8-supply:
> > +    description:
> > +      The input supply for SWITCH_REG1.
> > +
> > +  vcc9-supply:
> > +    description:
> > +      The input supply for LDO_REG4 and LDO_REG5.
> > +
> > +  vcc10-supply:
> > +    description:
> > +      The input supply for LDO_REG6.
> > +
> > +  vcc11-supply:
> > +    description:
> > +      The input supply for LDO_REG8.
> > +
> > +  vcc12-supply:
> > +    description:
> > +      The input supply for SWITCH_REG2.
> > +
> > +  vddio-supply:
> > +    description:
> > +      The input supply for digital IO.
> > +
> > +  dvs-gpios:
> > +    description: |
> > +      buck1/2 can be controlled by gpio dvs, this is GPIO specifiers for
> > +      2 host gpio's used for dvs. The format of the gpio specifier
> > +      depends in the gpio controller. If DVS GPIOs aren't present,
> > +      voltage changes will happen very quickly with no slow ramp time.
> > +    maxItems: 2
> > +
> > +  regulators:
> > +    type: object
> > +    patternProperties:
> > +      "^(DCDC_REG[1-4]|LDO_REG[1-8]|SWITCH_REG[1-2])$":
> > +        type: object
> > +        $ref: ../regulator/regulator.yaml#
> > +    unevaluatedProperties: false
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - interrupts
> > +  - "#clock-cells"
> 
> Is this actually required (ditto elsewhere)? Technically it's only necessary
> if there are any clock consumers targeting this node, so arguably it should
> be the clock binding's responsibility to validate that.
> 
> It wouldn't make much sense for a dedicated clock controller to omit
> #clock-cells such that it couldn't have any consumers, but given that these
> things are primarily PMICs I think it's reasonable to allow a board not to
> care about the clocks at all if it doesn't use them. I know that the
> original binding claimed it was required, but if we're already relaxing that
> for RK805 here then we may as well relax it entirely.

Fair enough. However, if the consumer could be in an overlay, then I 
think we want it to be required and not make the overlay add the 
property. Properties just appearing within nodes at runtime is likely 
not well supported in OSs.

Rob