Re: [PATCH v2 10/19] dt-bindings: dma: ti: Add document for K3 BCDMA

Peter Ujfalusi
2020-12-08T06:40:22Z

Hi Rob,

On 07/12/2020 21.42, Rob Herring wrote:
> On Tue, Nov 17, 2020 at 12:56:47PM +0200, Peter Ujfalusi wrote:
>> New binding document for
>> Texas Instruments K3 Block Copy DMA (BCDMA).
>>
>> BCDMA is introduced as part of AM64.
>>
>> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
>> ---
>> .../devicetree/bindings/dma/ti/k3-bcdma.yaml | 175 ++++++++++++++++++
>> 1 file changed, 175 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml b/Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml
>> new file mode 100644
>> index 000000000000..c6d76641ebec
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml
>> @@ -0,0 +1,175 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/dma/ti/k3-bcdma.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Texas Instruments K3 DMSS BCDMA Device Tree Bindings
>> +
>> +maintainers:
>> + - Peter Ujfalusi <peter.ujfalusi@ti.com>
>> +
>> +description: |
>> + The Block Copy DMA (BCDMA) is intended to perform similar functions as the TR
>> + mode channels of K3 UDMA-P.
>> + BCDMA includes block copy channels and Split channels.
>> +
>> + Block copy channels mainly used for memory to memory transfers, but with
>> + optional triggers a block copy channel can service peripherals by accessing
>> + directly to memory mapped registers or area.
>> +
>> + Split channels can be used to service PSI-L based peripherals.
>> + The peripherals can be PSI-L native or legacy, non PSI-L native peripherals
>> + with PDMAs. PDMA is tasked to act as a bridge between the PSI-L fabric and the
>> + legacy peripheral.
>> +
>> + PDMAs can be configured via BCDMA split channel's peer registers to match with
>> + the configuration of the legacy peripheral.
>> +
>> +allOf:
>> + - $ref: /schemas/dma/dma-controller.yaml#
>> +
>> +properties:
>> + "#dma-cells":
>> + const: 3
>> + description: |
>> + cell 1: type of the BCDMA channel to be used to service the peripheral:
>> + 0 - split channel
>> + 1 - block copy channel using global trigger 1
>> + 2 - block copy channel using global trigger 2
>> + 3 - block copy channel using local trigger
>> +
>> + cell 2: parameter for the channel:
>> + if cell 1 is 0 (split channel):
>> + PSI-L thread ID of the remote (to BCDMA) end.
>> + Valid ranges for thread ID depends on the data movement direction:
>> + for source thread IDs (rx): 0 - 0x7fff
>> + for destination thread IDs (tx): 0x8000 - 0xffff
>> +
>> + Please refer to the device documentation for the PSI-L thread map and
>> + also the PSI-L peripheral chapter for the correct thread ID.
>> + if cell 1 is 1 or 2 (block copy channel using global trigger):
>> + Unused, ignored
>> +
>> + The trigger must be configured for the channel externally to BCDMA,
>> + channels using global triggers should not be requested directly, but
>> + via DMA event router.
>> + if cell 1 is 3 (block copy channel using local trigger):
>> + bchan number of the locally triggered channel
>> +
>> + cell 3: ASEL value for the channel
>> +
>> + compatible:
>> + enum:
>> + - ti,am64-dmss-bcdma
>
> Typically, we put 'compatible' first.

OK.

>> + "#address-cells":
>> + const: 2
>> +
>> + "#size-cells":
>> + const: 2
>
> These apply to child nodes, but you don't have any.

True, I forgot to remove these.

>> +
>> + reg:
>> + maxItems: 5
>> +
>> + reg-names:
>> + items:
>> + - const: gcfg
>> + - const: bchanrt
>> + - const: rchanrt
>> + - const: tchanrt
>> + - const: ringrt
>> +
>> + msi-parent: true
>> +
>> + ti,asel:
>> + $ref: /schemas/types.yaml#/definitions/uint32
>> + description: ASEL value for non slave channels
>> +
>> + ti,sci-rm-range-bchan:
>> + $ref: /schemas/types.yaml#/definitions/uint32-array
>> + description: |
>> + Array of BCDMA block-copy channel resource subtypes for resource
>> + allocation for this host
>> + minItems: 1
>> + # Should be enough
>> + maxItems: 255
>> + items:
>> + maximum: 0x3f
>> +
>> + ti,sci-rm-range-tchan:
>> + $ref: /schemas/types.yaml#/definitions/uint32-array
>> + description: |
>> + Array of BCDMA split tx channel resource subtypes for resource allocation
>> + for this host
>> + minItems: 1
>> + # Should be enough
>> + maxItems: 255
>> + items:
>> + maximum: 0x3f
>> +
>> + ti,sci-rm-range-rchan:
>> + $ref: /schemas/types.yaml#/definitions/uint32-array
>> + description: |
>> + Array of BCDMA split rx channel resource subtypes for resource allocation
>> + for this host
>> + minItems: 1
>> + # Should be enough
>> + maxItems: 255
>> + items:
>> + maximum: 0x3f
>> +
>> +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
>> +
>> +unevaluatedProperties: false
>> +
>> +examples:
>> + - |+
>> + cbass_main {
>> + #address-cells = <2>;
>> + #size-cells = <2>;
>> +
>> + main_dmss {
>> + compatible = "simple-mfd";
>> + #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