On Tue, Sep 17, 2019 at 6:29 AM Simon Horman <horms@xxxxxxxxxxxx> wrote:
>
> On Mon, Sep 16, 2019 at 05:33:56PM +0200, Simon Horman wrote:
> > Convert Simple Power-Managed Bus bindings documentation to json-schema.
> >
> > As a side effect of this change only simple-pm-bus is used in example. A
> > follow-up patch will provide an example for the separately documented
> > Renesas Bus State Controller (BSC) that uses "renesas,bsc-sh73a0" and
> > "renesas,bsc" compat strings.
> >
> > Signed-off-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
> > ---
> > * Tested using:
> > # ARCH=arm64 make dtbs_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/bus/simple-pm-bus.yaml
> > # ARCH=arm make dtbs_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/bus/simple-pm-bus.yaml
> > ---
> > .../devicetree/bindings/bus/simple-pm-bus.txt | 44 --------------
> > .../devicetree/bindings/bus/simple-pm-bus.yaml | 68 ++++++++++++++++++++++
> > 2 files changed, 68 insertions(+), 44 deletions(-)
> > delete mode 100644 Documentation/devicetree/bindings/bus/simple-pm-bus.txt
> > create mode 100644 Documentation/devicetree/bindings/bus/simple-pm-bus.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/bus/simple-pm-bus.txt b/Documentation/devicetree/bindings/bus/simple-pm-bus.txt
> > deleted file mode 100644
> > index 6f15037131ed..000000000000
> > --- a/Documentation/devicetree/bindings/bus/simple-pm-bus.txt
> > +++ /dev/null
> > @@ -1,44 +0,0 @@
> > -Simple Power-Managed Bus
> > -========================
> > -
> > -A Simple Power-Managed Bus is a transparent bus that doesn't need a real
> > -driver, as it's typically initialized by the boot loader.
> > -
> > -However, its bus controller is part of a PM domain, or under the control of a
> > -functional clock. Hence, the bus controller's PM domain and/or clock must be
> > -enabled for child devices connected to the bus (either on-SoC or externally)
> > -to function.
> > -
> > -While "simple-pm-bus" follows the "simple-bus" set of properties, as specified
> > -in the Devicetree Specification, it is not an extension of "simple-bus".
> > -
> > -
> > -Required properties:
> > - - compatible: Must contain at least "simple-pm-bus".
> > - Must not contain "simple-bus".
> > - It's recommended to let this be preceded by one or more
> > - vendor-specific compatible values.
> > - - #address-cells, #size-cells, ranges: Must describe the mapping between
> > - parent address and child address spaces.
> > -
> > -Optional platform-specific properties for clock or PM domain control (at least
> > -one of them is required):
> > - - clocks: Must contain a reference to the functional clock(s),
> > - - power-domains: Must contain a reference to the PM domain.
> > -Please refer to the binding documentation for the clock and/or PM domain
> > -providers for more details.
> > -
> > -
> > -Example:
> > -
> > - bsc: bus@fec10000 {
> > - compatible = "renesas,bsc-sh73a0", "renesas,bsc",
> > - "simple-pm-bus";
> > - #address-cells = <1>;
> > - #size-cells = <1>;
> > - ranges = <0 0 0x20000000>;
> > - reg = <0xfec10000 0x400>;
> > - interrupts = <0 39 IRQ_TYPE_LEVEL_HIGH>;
> > - clocks = <&zb_clk>;
> > - power-domains = <&pd_a4s>;
> > - };
> > diff --git a/Documentation/devicetree/bindings/bus/simple-pm-bus.yaml b/Documentation/devicetree/bindings/bus/simple-pm-bus.yaml
> > new file mode 100644
> > index 000000000000..72a3644974e3
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/bus/simple-pm-bus.yaml
> > @@ -0,0 +1,68 @@
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/bus/simple-pm-bus.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Simple Power-Managed Bus
> > +
> > +maintainers:
> > + - Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> > +
> > +description: |
> > + A Simple Power-Managed Bus is a transparent bus that doesn't need a real
> > + driver, as it's typically initialized by the boot loader.
> > +
> > + However, its bus controller is part of a PM domain, or under the control
> > + of a functional clock. Hence, the bus controller's PM domain and/or
> > + clock must be enabled for child devices connected to the bus (either
> > + on-SoC or externally) to function.
> > +
> > + While "simple-pm-bus" follows the "simple-bus" set of properties, as
> > + specified in the Devicetree Specification, it is not an extension of
> > + "simple-bus".
> > +
> > +
>
> There is an extra blank line above, I will plan to remove it in v2.
>
> > +properties:
> > + compatible:
> > + items:
> > + - const: simple-pm-bus
>
> The following patch, for Renesas BSC, also
> describes the simple-pm-bus but also requires other compatible
> strings to be present.
>
> In order to facilitate that I tried the following:
>
> compatible:
> contains:
> const: simple-pm-bus
> additionalItems: true
>
> This allows make dtbs_check DT_SCHEMA_FILES=.../simple-pm-bus.yaml to pass
> in cases where there are more compat strings pesent. However
> make dtbs_check DT_SCHEMA_FILES=...renesas,bsc.yaml (schema file
> introduced in following patch) fails in the case
> where the only compat string is simple-pm-bus.
>
> make dtbs_check DT_SCHEMA_FILES=...renesas,bsc.yaml also fails
> due to the reg property not being present for the same compat case,
> which should be valid according to simple-pm-bus.yaml.
>
> Does anyone have any guidance on how to proceed?
You'll need a custom 'select' in renesas,bsc.yaml that leaves out
"simple-pm-bus". See "panel-lvds" users in linux-next for an example.
Rob
