[v3,6/6] dt-bindings: nvmem: add YAML schema for the ONIE tlv layout

  Add a schema for the ONIE tlv NVMEM layout that can be found on any ONIE
compatible networking device.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 .../bindings/nvmem/layouts/nvmem-layout.yaml  |   1 +
 .../nvmem/layouts/onie,tlv-layout.yaml        | 115 ++++++++++++++++++
 2 files changed, 116 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml
  

On Fri, Nov 04, 2022 at 05:38:33PM +0100, Miquel Raynal wrote:
> Add a schema for the ONIE tlv NVMEM layout that can be found on any ONIE
> compatible networking device.
> 
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> ---
>  .../bindings/nvmem/layouts/nvmem-layout.yaml  |   1 +
>  .../nvmem/layouts/onie,tlv-layout.yaml        | 115 ++++++++++++++++++
>  2 files changed, 116 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml
> 
> diff --git a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> index f64ea2fa362d..8512ee538c4c 100644
> --- a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> +++ b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> @@ -19,6 +19,7 @@ description: |
>  
>  oneOf:
>    - $ref: kontron,sl28-vpd.yaml
> +  - $ref: onie,tlv-layout.yaml
>  
>  properties:
>    compatible: true
> diff --git a/Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml b/Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml
> new file mode 100644
> index 000000000000..1d91277324ac
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml
> @@ -0,0 +1,115 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/nvmem/layouts/onie,tlv-layout.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: NVMEM layout of the ONIE tlv table
> +
> +maintainers:
> +  - Miquel Raynal <miquel.raynal@bootlin.com>
> +
> +description:
> +  Modern networking hardware implementing the Open Compute Project ONIE
> +  infrastructure shall provide a non-volatile memory with a table whose the
> +  content is well specified and gives many information about the manufacturer
> +  (name, country of manufacture, etc) as well as device caracteristics (serial
> +  number, hardware version, mac addresses, etc). The underlaying device type
> +  (flash, EEPROM,...) is not specified. The exact location of each value is also
> +  dynamic and should be discovered at run time because it depends on the
> +  parameters the manufacturer decided to embed.
> +
> +properties:
> +  compatible:
> +    const: onie,tlv-layout
> +
> +  product-name: true

This is a node? If so, you need:

type: object
additionalProperties: false

> +
> +  part-number: true
> +
> +  serial-number: true
> +
> +  mac-address:
> +    type: object
> +    description:
> +      Base MAC address for all on-module network interfaces. The first
> +      argument of the phandle will be treated as an offset.
> +
> +    properties:
> +      "#nvmem-cell-cells":
> +        const: 1
> +
> +    additionalProperties: false
> +
> +  manufacture-date: true
> +
> +  device-version: true
> +
> +  label-revision: true
> +
> +  platforn-name: true
> +
> +  onie-version: true
> +
> +  num-macs: true
> +
> +  manufacturer: true
> +
> +  country-code: true
> +
> +  vendor: true
> +
> +  diag-version: true
> +
> +  service-tag: true
> +
> +  vendor-extension: true
> +
> +required:
> +  - compatible
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    spi {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        eeprom@56 {
> +            compatible = "atmel,24c64";
> +            read-only;
> +            reg = <0x56>;
> +
> +            nvmem-layout {
> +                compatible = "onie,tlv-layout";
> +
> +                serial-number {
> +                };
> +            };
> +        };
> +    };
> +
> +  - |
> +    spi {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        flash@0 {
> +            compatible = "m25p80", "jedec,spi-nor";
> +            reg = <0>;
> +
> +            otp {
> +                compatible = "user-otp";
> +
> +                nvmem-layout {
> +                    compatible = "onie,tlv-layout";
> +
> +                    mac-address {
> +                        #nvmem-cell-cells = <1>;
> +                    };
> +                };
> +            };
> +        };
> +    };
> +...
> -- 
> 2.34.1
> 
>
  

Hi Rob,

robh@kernel.org wrote on Wed, 9 Nov 2022 22:00:55 -0600:

> On Fri, Nov 04, 2022 at 05:38:33PM +0100, Miquel Raynal wrote:
> > Add a schema for the ONIE tlv NVMEM layout that can be found on any ONIE
> > compatible networking device.
> > 
> > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> > ---
> >  .../bindings/nvmem/layouts/nvmem-layout.yaml  |   1 +
> >  .../nvmem/layouts/onie,tlv-layout.yaml        | 115 ++++++++++++++++++
> >  2 files changed, 116 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> > index f64ea2fa362d..8512ee538c4c 100644
> > --- a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> > +++ b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> > @@ -19,6 +19,7 @@ description: |
> >  
> >  oneOf:
> >    - $ref: kontron,sl28-vpd.yaml
> > +  - $ref: onie,tlv-layout.yaml
> >  
> >  properties:
> >    compatible: true
> > diff --git a/Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml b/Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml
> > new file mode 100644
> > index 000000000000..1d91277324ac
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml
> > @@ -0,0 +1,115 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/nvmem/layouts/onie,tlv-layout.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: NVMEM layout of the ONIE tlv table
> > +
> > +maintainers:
> > +  - Miquel Raynal <miquel.raynal@bootlin.com>
> > +
> > +description:
> > +  Modern networking hardware implementing the Open Compute Project ONIE
> > +  infrastructure shall provide a non-volatile memory with a table whose the
> > +  content is well specified and gives many information about the manufacturer
> > +  (name, country of manufacture, etc) as well as device caracteristics (serial
> > +  number, hardware version, mac addresses, etc). The underlaying device type
> > +  (flash, EEPROM,...) is not specified. The exact location of each value is also
> > +  dynamic and should be discovered at run time because it depends on the
> > +  parameters the manufacturer decided to embed.
> > +
> > +properties:
> > +  compatible:
> > +    const: onie,tlv-layout
> > +
> > +  product-name: true  
> 
> This is a node? If so, you need:
> 
> type: object
> additionalProperties: false

I thought referencing a schema under a property would be enough?

Indeed in nvmem.yaml we create the property nvmem-layout and make it
reference nvmem-layout.yaml. Then, in nvmem-layout.yaml:

	 oneOf:
	  - $ref: kontron,sl28-vpd.yaml
	  - $ref: onie,tlv-layout.yaml

we reference the different layouts that may apply (very much like what
you proposed to list the mtd partition parsers, if I got it right).

Isn't it enough?

Then if you look below there is an "additionalProperties: false"
defined.

> > +
> > +  part-number: true
> > +

[...]

> > +  service-tag: true
> > +
> > +  vendor-extension: true
> > +
> > +required:
> > +  - compatible
> > +
> > +additionalProperties: false

(here)

> > +
> > +examples:
> > +  - |
> > +    spi {
> > +        #address-cells = <1>;
> > +        #size-cells = <0>;
> > +
> > +        eeprom@56 {
> > +            compatible = "atmel,24c64";
> > +            read-only;
> > +            reg = <0x56>;
> > +
> > +            nvmem-layout {
> > +                compatible = "onie,tlv-layout";
> > +
> > +                serial-number {
> > +                };
> > +            };
> > +        };
> > +    };
> > +
> > +  - |
> > +    spi {
> > +        #address-cells = <1>;
> > +        #size-cells = <0>;
> > +
> > +        flash@0 {
> > +            compatible = "m25p80", "jedec,spi-nor";
> > +            reg = <0>;
> > +
> > +            otp {
> > +                compatible = "user-otp";
> > +
> > +                nvmem-layout {
> > +                    compatible = "onie,tlv-layout";
> > +
> > +                    mac-address {
> > +                        #nvmem-cell-cells = <1>;
> > +                    };
> > +                };
> > +            };
> > +        };
> > +    };
> > +...
> > -- 
> > 2.34.1
> > 
> >   


Thanks,
Miquèl
  

On Thu, Nov 10, 2022 at 09:50:34AM +0100, Miquel Raynal wrote:
> Hi Rob,
> 
> robh@kernel.org wrote on Wed, 9 Nov 2022 22:00:55 -0600:
> 
> > On Fri, Nov 04, 2022 at 05:38:33PM +0100, Miquel Raynal wrote:
> > > Add a schema for the ONIE tlv NVMEM layout that can be found on any ONIE
> > > compatible networking device.
> > > 
> > > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> > > ---
> > >  .../bindings/nvmem/layouts/nvmem-layout.yaml  |   1 +
> > >  .../nvmem/layouts/onie,tlv-layout.yaml        | 115 ++++++++++++++++++
> > >  2 files changed, 116 insertions(+)
> > >  create mode 100644 Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml
> > > 
> > > diff --git a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> > > index f64ea2fa362d..8512ee538c4c 100644
> > > --- a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> > > +++ b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> > > @@ -19,6 +19,7 @@ description: |
> > >  
> > >  oneOf:
> > >    - $ref: kontron,sl28-vpd.yaml
> > > +  - $ref: onie,tlv-layout.yaml
> > >  
> > >  properties:
> > >    compatible: true
> > > diff --git a/Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml b/Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml
> > > new file mode 100644
> > > index 000000000000..1d91277324ac
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml
> > > @@ -0,0 +1,115 @@
> > > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/nvmem/layouts/onie,tlv-layout.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: NVMEM layout of the ONIE tlv table
> > > +
> > > +maintainers:
> > > +  - Miquel Raynal <miquel.raynal@bootlin.com>
> > > +
> > > +description:
> > > +  Modern networking hardware implementing the Open Compute Project ONIE
> > > +  infrastructure shall provide a non-volatile memory with a table whose the
> > > +  content is well specified and gives many information about the manufacturer
> > > +  (name, country of manufacture, etc) as well as device caracteristics (serial
> > > +  number, hardware version, mac addresses, etc). The underlaying device type
> > > +  (flash, EEPROM,...) is not specified. The exact location of each value is also
> > > +  dynamic and should be discovered at run time because it depends on the
> > > +  parameters the manufacturer decided to embed.
> > > +
> > > +properties:
> > > +  compatible:
> > > +    const: onie,tlv-layout
> > > +
> > > +  product-name: true  
> > 
> > This is a node? If so, you need:
> > 
> > type: object
> > additionalProperties: false
> 
> I thought referencing a schema under a property would be enough?
> 
> Indeed in nvmem.yaml we create the property nvmem-layout and make it
> reference nvmem-layout.yaml. Then, in nvmem-layout.yaml:
> 
> 	 oneOf:
> 	  - $ref: kontron,sl28-vpd.yaml
> 	  - $ref: onie,tlv-layout.yaml
> 
> we reference the different layouts that may apply (very much like what
> you proposed to list the mtd partition parsers, if I got it right).
> 
> Isn't it enough?

No. It is enough to allow the property, but nothing defines what it must 
be (a node) and what the node contains in the case of empty nodes. Try 
adding 'product-name = "foo";' and it won't warn.

Rob
  

Hi Rob,

robh@kernel.org wrote on Thu, 10 Nov 2022 08:05:45 -0600:

> On Thu, Nov 10, 2022 at 09:50:34AM +0100, Miquel Raynal wrote:
> > Hi Rob,
> > 
> > robh@kernel.org wrote on Wed, 9 Nov 2022 22:00:55 -0600:
> >   
> > > On Fri, Nov 04, 2022 at 05:38:33PM +0100, Miquel Raynal wrote:  
> > > > Add a schema for the ONIE tlv NVMEM layout that can be found on any ONIE
> > > > compatible networking device.
> > > > 
> > > > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> > > > ---
> > > >  .../bindings/nvmem/layouts/nvmem-layout.yaml  |   1 +
> > > >  .../nvmem/layouts/onie,tlv-layout.yaml        | 115 ++++++++++++++++++
> > > >  2 files changed, 116 insertions(+)
> > > >  create mode 100644 Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml
> > > > 
> > > > diff --git a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> > > > index f64ea2fa362d..8512ee538c4c 100644
> > > > --- a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> > > > +++ b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> > > > @@ -19,6 +19,7 @@ description: |
> > > >  
> > > >  oneOf:
> > > >    - $ref: kontron,sl28-vpd.yaml
> > > > +  - $ref: onie,tlv-layout.yaml
> > > >  
> > > >  properties:
> > > >    compatible: true
> > > > diff --git a/Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml b/Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml
> > > > new file mode 100644
> > > > index 000000000000..1d91277324ac
> > > > --- /dev/null
> > > > +++ b/Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml
> > > > @@ -0,0 +1,115 @@
> > > > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > > > +%YAML 1.2
> > > > +---
> > > > +$id: http://devicetree.org/schemas/nvmem/layouts/onie,tlv-layout.yaml#
> > > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > > +
> > > > +title: NVMEM layout of the ONIE tlv table
> > > > +
> > > > +maintainers:
> > > > +  - Miquel Raynal <miquel.raynal@bootlin.com>
> > > > +
> > > > +description:
> > > > +  Modern networking hardware implementing the Open Compute Project ONIE
> > > > +  infrastructure shall provide a non-volatile memory with a table whose the
> > > > +  content is well specified and gives many information about the manufacturer
> > > > +  (name, country of manufacture, etc) as well as device caracteristics (serial
> > > > +  number, hardware version, mac addresses, etc). The underlaying device type
> > > > +  (flash, EEPROM,...) is not specified. The exact location of each value is also
> > > > +  dynamic and should be discovered at run time because it depends on the
> > > > +  parameters the manufacturer decided to embed.
> > > > +
> > > > +properties:
> > > > +  compatible:
> > > > +    const: onie,tlv-layout
> > > > +
> > > > +  product-name: true    
> > > 
> > > This is a node? If so, you need:
> > > 
> > > type: object
> > > additionalProperties: false  
> > 
> > I thought referencing a schema under a property would be enough?
> > 
> > Indeed in nvmem.yaml we create the property nvmem-layout and make it
> > reference nvmem-layout.yaml. Then, in nvmem-layout.yaml:
> > 
> > 	 oneOf:
> > 	  - $ref: kontron,sl28-vpd.yaml
> > 	  - $ref: onie,tlv-layout.yaml
> > 
> > we reference the different layouts that may apply (very much like what
> > you proposed to list the mtd partition parsers, if I got it right).
> > 
> > Isn't it enough?  
> 
> No. It is enough to allow the property, but nothing defines what it must 
> be (a node) and what the node contains in the case of empty nodes. Try 
> adding 'product-name = "foo";' and it won't warn.

There was a misunderstanding on my side. I thought your comment was
about the nvmem-layout node. Actually you were commenting about all the
sub-nodes defining nvmem-cells inside, so I'm fully aligned with your
response.

However, if I understood it correctly, you basically said that:

	property:
	  $ref: foo.yaml

is not the same as:

	property:
	  type: object
	  $ref: foo.yaml

If that's the case, then should we consider dropping this patch (which
you agreed with in the first place)?

https://lore.kernel.org/linux-mtd/20221104164718.1290859-17-miquel.raynal@bootlin.com/T/#u 

Thanks,
Miquèl
  

On Thu, Nov 10, 2022 at 06:43:34PM +0100, Miquel Raynal wrote:
> Hi Rob,
> 
> robh@kernel.org wrote on Thu, 10 Nov 2022 08:05:45 -0600:
> 
> > On Thu, Nov 10, 2022 at 09:50:34AM +0100, Miquel Raynal wrote:
> > > Hi Rob,
> > > 
> > > robh@kernel.org wrote on Wed, 9 Nov 2022 22:00:55 -0600:
> > >   
> > > > On Fri, Nov 04, 2022 at 05:38:33PM +0100, Miquel Raynal wrote:  
> > > > > Add a schema for the ONIE tlv NVMEM layout that can be found on any ONIE
> > > > > compatible networking device.
> > > > > 
> > > > > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> > > > > ---
> > > > >  .../bindings/nvmem/layouts/nvmem-layout.yaml  |   1 +
> > > > >  .../nvmem/layouts/onie,tlv-layout.yaml        | 115 ++++++++++++++++++
> > > > >  2 files changed, 116 insertions(+)
> > > > >  create mode 100644 Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml
> > > > > 
> > > > > diff --git a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> > > > > index f64ea2fa362d..8512ee538c4c 100644
> > > > > --- a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> > > > > +++ b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> > > > > @@ -19,6 +19,7 @@ description: |
> > > > >  
> > > > >  oneOf:
> > > > >    - $ref: kontron,sl28-vpd.yaml
> > > > > +  - $ref: onie,tlv-layout.yaml
> > > > >  
> > > > >  properties:
> > > > >    compatible: true
> > > > > diff --git a/Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml b/Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml
> > > > > new file mode 100644
> > > > > index 000000000000..1d91277324ac
> > > > > --- /dev/null
> > > > > +++ b/Documentation/devicetree/bindings/nvmem/layouts/onie,tlv-layout.yaml
> > > > > @@ -0,0 +1,115 @@
> > > > > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > > > > +%YAML 1.2
> > > > > +---
> > > > > +$id: http://devicetree.org/schemas/nvmem/layouts/onie,tlv-layout.yaml#
> > > > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > > > +
> > > > > +title: NVMEM layout of the ONIE tlv table
> > > > > +
> > > > > +maintainers:
> > > > > +  - Miquel Raynal <miquel.raynal@bootlin.com>
> > > > > +
> > > > > +description:
> > > > > +  Modern networking hardware implementing the Open Compute Project ONIE
> > > > > +  infrastructure shall provide a non-volatile memory with a table whose the
> > > > > +  content is well specified and gives many information about the manufacturer
> > > > > +  (name, country of manufacture, etc) as well as device caracteristics (serial
> > > > > +  number, hardware version, mac addresses, etc). The underlaying device type
> > > > > +  (flash, EEPROM,...) is not specified. The exact location of each value is also
> > > > > +  dynamic and should be discovered at run time because it depends on the
> > > > > +  parameters the manufacturer decided to embed.
> > > > > +
> > > > > +properties:
> > > > > +  compatible:
> > > > > +    const: onie,tlv-layout
> > > > > +
> > > > > +  product-name: true    
> > > > 
> > > > This is a node? If so, you need:
> > > > 
> > > > type: object
> > > > additionalProperties: false  
> > > 
> > > I thought referencing a schema under a property would be enough?
> > > 
> > > Indeed in nvmem.yaml we create the property nvmem-layout and make it
> > > reference nvmem-layout.yaml. Then, in nvmem-layout.yaml:
> > > 
> > > 	 oneOf:
> > > 	  - $ref: kontron,sl28-vpd.yaml
> > > 	  - $ref: onie,tlv-layout.yaml
> > > 
> > > we reference the different layouts that may apply (very much like what
> > > you proposed to list the mtd partition parsers, if I got it right).
> > > 
> > > Isn't it enough?  
> > 
> > No. It is enough to allow the property, but nothing defines what it must 
> > be (a node) and what the node contains in the case of empty nodes. Try 
> > adding 'product-name = "foo";' and it won't warn.
> 
> There was a misunderstanding on my side. I thought your comment was
> about the nvmem-layout node. Actually you were commenting about all the
> sub-nodes defining nvmem-cells inside, so I'm fully aligned with your
> response.
> 
> However, if I understood it correctly, you basically said that:
> 
> 	property:
> 	  $ref: foo.yaml
> 
> is not the same as:
> 
> 	property:
> 	  type: object
> 	  $ref: foo.yaml
> 
> If that's the case, then should we consider dropping this patch (which
> you agreed with in the first place)?

From a json-schema standpoint, they may not be the same. You can't know 
without knowing what's in foo.yaml. They are the same only if foo.yaml 
contains 'type: object'. It does for us because the tools will add 
'type: object' to the top-level of every schema file.


properties:
  property:
    properties:
      foo: {}

These would all pass validation with the above:

property;
property = "bar";

More generally, json-schema's behavior is if a keyword doesn't apply for 
an instance, just silently ignore it. So while 'properties' keyword only 
makes sense on an object or maxItems on an array, json-schema doesn't 
care. The dtschema tools do a bit to counteract that.

Rob