Re: [PATCH 09/18] dt-bindings: dma: ti: Add document for K3 BCDMA

Peter Ujfalusi
2020-10-07T09:08:57Z

On 06/10/2020 22.29, Rob Herring wrote:
> On Wed, Sep 30, 2020 at 12:14:03PM +0300, Peter Ujfalusi wrote:
>> New binding document for
>> Texas Instruments K3 Block Copy DMA (BCDMA).
>>
>> BCDMA is introduced as part of AM64.
>>

...

>
>> + ti,sci:
>> + description: phandle to TI-SCI compatible System controller node
>> + allOf:
>> + - $ref: /schemas/types.yaml#/definitions/phandle
>> +
>> + ti,sci-dev-id:
>> + description: TI-SCI device id of BCDMA
>> + allOf:
>> + - $ref: /schemas/types.yaml#/definitions/uint32
>
> We have a common definition for these.

Yes, in arm/keystone/ti,k3-sci-common.yaml, but I could not get to use
that as reference.

I can not list it under the topmost allOf and drop the ti,sci and
ti,sci-dev-id like this:

allOf:
- $ref: /schemas/dma/dma-controller.yaml#
- $ref: /schemas/arm/keystone/ti,k3-sci-common.yaml#

It results:
CHKDT Documentation/devicetree/bindings/processed-schema-examples.json
DTEX Documentation/devicetree/bindings/dma/ti/k3-bcdma.example.dts
SCHEMA Documentation/devicetree/bindings/processed-schema-examples.json
DTC Documentation/devicetree/bindings/dma/ti/k3-bcdma.example.dt.yaml
CHECK Documentation/devicetree/bindings/dma/ti/k3-bcdma.example.dt.yaml
Documentation/devicetree/bindings/dma/ti/k3-bcdma.example.dt.yaml:
dma-controller@485c0100: 'ti,sci', 'ti,sci-dev-id' do not match any of
the regexes: 'pinctrl-[0-9]+'
From schema: Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml

If I remove the "additionalProperties: false" from the schema file, then
it compiles fine.

>
>> +
>> + ti,asel:
>> + description: ASEL value for non slave channels
>> + allOf:
>
> You no longer need 'allOf' here.

OK, I changed it in all instances.

>
>> + - $ref: /schemas/types.yaml#/definitions/uint32
>> +
>> + ti,sci-rm-range-bchan:
>> + description: |
>> + Array of BCDMA block-copy channel resource subtypes for resource
>> + allocation for this host
>> + allOf:
>> + - $ref: /schemas/types.yaml#/definitions/uint32-array
>> + minItems: 1
>> + # Should be enough
>> + maxItems: 255
>
> Are there constraints for the individual elements?

In practice the subtype ID is 6bits number.
Should I add limits to individual elements?

>> +
>> + ti,sci-rm-range-tchan:
>> + description: |
>> + Array of BCDMA split tx channel resource subtypes for resource allocation
>> + for this host
>> + allOf:
>> + - $ref: /schemas/types.yaml#/definitions/uint32-array
>> + minItems: 1
>> + # Should be enough
>> + maxItems: 255
>> +
>> + ti,sci-rm-range-rchan:
>> + description: |
>> + Array of BCDMA split rx channel resource subtypes for resource allocation
>> + for this host
>> + allOf:
>> + - $ref: /schemas/types.yaml#/definitions/uint32-array
>> + minItems: 1
>> + # Should be enough
>> + maxItems: 255
>> +
>> +required:
>> + - compatible
>> + - "#address-cells"
>> + - "#size-cells"
>> + - "#dma-cells"
>> + - reg
>> + - reg-names
>> + - msi-parent
>> + - ti,sci
>> + - ti,sci-dev-id
>> + - ti,sci-rm-range-bchan
>> + - ti,sci-rm-range-tchan
>> + - ti,sci-rm-range-rchan
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> + - |+
>> + cbass_main {
>> + #address-cells = <2>;
>> + #size-cells = <2>;
>> +
>> + main_dmss {
>> + compatible = "simple-mfd";
>
> IMO, if it is memory-mapped, then you should be using 'simple-bus'.

We had the same discussion when I introduced the k3-udma binding and we
have concluded on the simple-mfd as DMSS is not a bus, but contains
different peripherals.

>
>> + #address-cells = <2>;
>> + #size-cells = <2>;
>> + dma-ranges;
>> + ranges;
>> +
>> + ti,sci-dev-id = <25>;
>> +
>> + main_bcdma: dma-controller@485c0100 {
>> + compatible = "ti,am64-dmss-bcdma";
>> + #address-cells = <2>;
>> + #size-cells = <2>;
>> +
>> + reg = <0x0 0x485c0100 0x0 0x100>,
>> + <0x0 0x4c000000 0x0 0x20000>,
>> + <0x0 0x4a820000 0x0 0x20000>,
>> + <0x0 0x4aa40000 0x0 0x20000>,
>> + <0x0 0x4bc00000 0x0 0x100000>;
>> + reg-names = "gcfg", "bchanrt", "rchanrt", "tchanrt", "ringrt";
>> + msi-parent = <&inta_main_dmss>;
>> + #dma-cells = <3>;
>> +
>> + ti,sci = <&dmsc>;
>> + ti,sci-dev-id = <26>;
>> +
>> + ti,sci-rm-range-bchan = <0x20>; /* BLOCK_COPY_CHAN */
>> + ti,sci-rm-range-rchan = <0x21>; /* SPLIT_TR_RX_CHAN */
>> + ti,sci-rm-range-tchan = <0x22>; /* SPLIT_TR_TX_CHAN */
>> + };
>> + };
>> + };
>> --
>> Peter
>>
>> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
>> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
>>

- Péter