Re: [PATCH v2 04/24] dt-bindings: net: dwmac: Refactor snps,*-config properties

Rob Herring
2021-02-10T01:07:25Z

On Mon, Feb 08, 2021 at 04:55:48PM +0300, Serge Semin wrote:
> Currently the "snps,axi-config", "snps,mtl-rx-config" and
> "snps,mtl-tx-config" properties are declared as a single phandle reference
> to a node with corresponding parameters defined. That's not good for
> several reasons. First of all scattering around a device tree some
> particular device-specific configs with no visual relation to that device
> isn't suitable from maintainability point of view. That leads to a
> disturbed representation of the actual device tree mixing actual device
> nodes and some vendor-specific configs. Secondly using the same configs
> set for several device nodes doesn't represent well the devices structure,
> since the interfaces these configs describe in hardware belong to
> different devices and may actually differ. In the later case having the
> configs node separated from the corresponding device nodes gets to be
> even unjustified.
>
> So instead of having a separate DW *MAC configs nodes we suggest to
> define them as sub-nodes of the device nodes, which interfaces they
> actually describe. By doing so we'll make the DW *MAC nodes visually
> correct describing all the aspects of the IP-core configuration. Thus
> we'll be able to describe the configs sub-nodes bindings right in the
> snps,dwmac.yaml file.
>
> Note the former "snps,axi-config", "snps,mtl-rx-config" and
> "snps,mtl-tx-config" properties have been marked as deprecated in favor of
> the added by this commit "axi-config", "mtl-rx-config" and "mtl-tx-config"
> sub-nodes respectively.
>
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
>
> ---
>
> Note this change will work only if DT-schema tool is fixed like this:
>
> --- a/meta-schemas/nodes.yaml 2021-02-08 14:20:56.732447780 +0300
> +++ b/meta-schemas/nodes.yaml 2021-02-08 14:21:00.736492245 +0300
> @@ -22,6 +22,7 @@
> - unevaluatedProperties
> - deprecated
> - required
> + - not
> - allOf
> - anyOf
> - oneOf

Can you send me a patch or GH PR. There is another way to express. More
below.

>
> So a property with name "not" would be allowed and the "not-required"
> pattern would work.
>
> Changelog v2:
> - Add the new sub-nodes "axi-config", "mtl-rx-config" and "mtl-tx-config"
> describing the nodes now deprecated properties were supposed to
> refer to.
> - Fix invalid identation in the "snps,route-*" property settings.
> - Use correct syntax of the JSON pointers, so the later would begin
> with a '/' after the '#'.
> ---
> .../devicetree/bindings/net/snps,dwmac.yaml | 389 +++++++++++++-----
> 1 file changed, 297 insertions(+), 92 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/net/snps,dwmac.yaml b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
> index 03d58bf9965f..4dda9ffa822c 100644
> --- a/Documentation/devicetree/bindings/net/snps,dwmac.yaml
> +++ b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
> @@ -150,73 +150,264 @@ properties:
> in a different mode than the PHY in order to function.
>
> snps,axi-config:
> + deprecated: true
> $ref: /schemas/types.yaml#/definitions/phandle
> description:
> - AXI BUS Mode parameters. Phandle to a node that can contain the
> - following properties
> - * snps,lpi_en, enable Low Power Interface
> - * snps,xit_frm, unlock on WoL
> - * snps,wr_osr_lmt, max write outstanding req. limit
> - * snps,rd_osr_lmt, max read outstanding req. limit
> - * snps,kbbe, do not cross 1KiB boundary.
> - * snps,blen, this is a vector of supported burst length.
> - * snps,fb, fixed-burst
> - * snps,mb, mixed-burst
> - * snps,rb, rebuild INCRx Burst
> + AXI BUS Mode parameters. Phandle to a node that contains the properties
> + described in the 'axi-config' sub-node.
> +
> + axi-config:
> + type: object
> + description: AXI BUS Mode parameters
> +
> + properties:
> + snps,lpi_en:
> + $ref: /schemas/types.yaml#/definitions/flag
> + description: Enable Low Power Interface
> +
> + snps,xit_frm:
> + $ref: /schemas/types.yaml#/definitions/flag
> + description: Unlock on WoL
> +
> + snps,wr_osr_lmt:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description: Max write outstanding req. limit
> + default: 1
> + minimum: 0
> + maximum: 15
> +
> + snps,rd_osr_lmt:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description: Max read outstanding req. limit
> + default: 1
> + minimum: 0
> + maximum: 15
> +
> + snps,kbbe:
> + $ref: /schemas/types.yaml#/definitions/flag
> + description: Do not cross 1KiB boundary
> +
> + snps,blen:
> + $ref: /schemas/types.yaml#/definitions/uint32-array
> + description: A vector of supported burst lengths
> + minItems: 7
> + maxItems: 7
> + items:
> + enum: [256, 128, 64, 32, 16, 8, 4, 0]
> +
> + snps,fb:
> + $ref: /schemas/types.yaml#/definitions/flag
> + description: Fixed-burst
> +
> + snps,mb:
> + $ref: /schemas/types.yaml#/definitions/flag
> + description: Mixed-burst
> +
> + snps,rb:
> + $ref: /schemas/types.yaml#/definitions/flag
> + description: Rebuild INCRx Burst
> +
> + additionalProperties: false
>
> snps,mtl-rx-config:

You could keep these pointing to child nodes to avoid driver changes.

> + deprecated: true
> $ref: /schemas/types.yaml#/definitions/phandle
> description:
> - Multiple RX Queues parameters. Phandle to a node that can
> - contain the following properties
> - * snps,rx-queues-to-use, number of RX queues to be used in the
> - driver
> - * Choose one of these RX scheduling algorithms
> - * snps,rx-sched-sp, Strict priority
> - * snps,rx-sched-wsp, Weighted Strict priority
> - * For each RX queue
> - * Choose one of these modes
> - * snps,dcb-algorithm, Queue to be enabled as DCB
> - * snps,avb-algorithm, Queue to be enabled as AVB
> - * snps,map-to-dma-channel, Channel to map
> - * Specifiy specific packet routing
> - * snps,route-avcp, AV Untagged Control packets
> - * snps,route-ptp, PTP Packets
> - * snps,route-dcbcp, DCB Control Packets
> - * snps,route-up, Untagged Packets
> - * snps,route-multi-broad, Multicast & Broadcast Packets
> - * snps,priority, bitmask of the tagged frames priorities assigned to
> - the queue
> + Multiple RX Queues parameters. Phandle to a node that contains the
> + properties described in the 'mtl-rx-config' sub-node.
> +
> + mtl-rx-config:
> + type: object
> + description: Multiple RX Queues parameters
> +
> + properties:
> + snps,rx-queues-to-use:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description: Number of RX queues to be used in the driver
> + default: 1
> + minimum: 1
> +
> + patternProperties:
> + "^snps,rx-sched-(sp|wsp)$":
> + $ref: /schemas/types.yaml#/definitions/flag
> + description: Strict/Weighted Strict RX scheduling priority
> +
> + "^queue[0-9]$":
> + type: object
> + description: Each RX Queue parameters
> +
> + properties:
> + snps,map-to-dma-channel:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description: DMA channel to map
> +
> + snps,priority:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description: RX queue priority
> + minimum: 0
> + maximum: 15
> +
> + patternProperties:
> + "^snps,(dcb|avb)-algorithm$":
> + $ref: /schemas/types.yaml#/definitions/flag
> + description: Enable Queue as DCB/AVB
> +
> + "^snps,route-(avcp|ptp|dcbcp|up|multi-broad)$":
> + $ref: /schemas/types.yaml#/definitions/flag
> + description:
> + AV Untagged/PTP/DCB Control/Untagged/Multicast & Broadcast
> + packets routing respectively.
> +
> + additionalProperties: false
> +
> + # Choose only one of the Queue modes and the packets routing
> + allOf:
> + - not:
> + required:
> + - snps,dcb-algorithm
> + - snps,avb-algorithm
> + - oneOf:
> + - required:
> + - snps,route-avcp
> + - required:
> + - snps,route-ptp
> + - required:
> + - snps,route-dcbcp
> + - required:
> + - snps,route-up
> + - required:
> + - snps,route-multi-broad
> + - not:
> + anyOf:
> + - required:
> + - snps,route-avcp
> + - required:
> + - snps,route-ptp
> + - required:
> + - snps,route-dcbcp
> + - required:
> + - snps,route-up
> + - required:
> + - snps,route-multi-broad

This 'not: ..." could be:

properties:
snps,route-avcp: false
snps,route-ptp: false
snps,route-dcbcp: false
snps,route-up: false
snps,route-multi-broad: false

Not sure which one is better. Using required everywhere or more
concise...

(Really, 'route' should have taken a value and the schema would be
greatly simplified. Oh well.)

> +
> + additionalProperties: false
> +
> + # Choose one of the RX scheduling algorithms
> + not:
> + required:
> + - snps,rx-sched-sp
> + - snps,rx-sched-wsp

I guess this is the problematic one. The rest should be hidden behind
conditionals (a common loophole in meta-schema checks). You could do
that here:

allOf:
- not:
...

But why not just make one of the 2 properties required? You're already
changing things.

Rob