On 06-09-19, 17:18, Peter Ujfalusi wrote: > On systems where multiple DMA controllers available, none Slave (for example On systems with multiple DMA controllers, non Slave... > memcpy operation) users can not be described in DT as there is no device > involved from the DMA controller's point of view, DMA binding is not usable. > However in these systems still a peripheral might need to be serviced by or > it is better to serviced by specific DMA controller. > When a memcpy is used to/from a memory mapped region for example a DMA in the > same domain can perform better. > For generic software modules doing mem 2 mem operations it also matter that > they will get a channel from a controller which is faster in DDR to DDR mode > rather then from the first controller happen to be loaded. > > This property is inherited, so it may be specified in a device node or in any > of its parent nodes. > > Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx> > --- > .../devicetree/bindings/dma/dma-domain.yaml | 59 +++++++++++++++++++ > 1 file changed, 59 insertions(+) > create mode 100644 Documentation/devicetree/bindings/dma/dma-domain.yaml > > diff --git a/Documentation/devicetree/bindings/dma/dma-domain.yaml b/Documentation/devicetree/bindings/dma/dma-domain.yaml > new file mode 100644 > index 000000000000..c2f182f30081 > --- /dev/null > +++ b/Documentation/devicetree/bindings/dma/dma-domain.yaml > @@ -0,0 +1,59 @@ > +# SPDX-License-Identifier: GPL-2.0 > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/dma/dma-controller.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: DMA Domain Controller Definition > + > +maintainers: > + - Vinod Koul <vkoul@xxxxxxxxxx> > + > +allOf: > + - $ref: "dma-controller.yaml#" > + > +description: > + On systems where multiple DMA controllers available, none Slave (for example > + memcpy operation) users can not be described in DT as there is no device > + involved from the DMA controller's point of view, DMA binding is not usable. > + However in these systems still a peripheral might need to be serviced by or > + it is better to serviced by specific DMA controller. > + When a memcpy is used to/from a memory mapped region for example a DMA in the > + same domain can perform better. > + For generic software modules doing mem 2 mem operations it also matter that > + they will get a channel from a controller which is faster in DDR to DDR mode > + rather then from the first controller happen to be loaded. > + > + This property is inherited, so it may be specified in a device node or in any > + of its parent nodes. > + > +properties: > + $dma-domain-controller: > + $ref: /schemas/types.yaml#definitions/phandle > + description: > + phande to the DMA controller node which should be used for the device or > + domain. > + > +examples: > + - | > + / { > + model = "Texas Instruments K3 AM654 SoC"; > + compatible = "ti,am654"; > + interrupt-parent = <&gic500>; > + /* For modules without device, DDR to DDR is faster on main UDMAP */ > + dma-domain-controller = <&main_udmap>; > + #address-cells = <2>; > + #size-cells = <2>; > + ... > + }; > + > + &cbass_main { > + /* For modules within MAIN domain, use main UDMAP */ > + dma-domain-controller = <&main_udmap>; > + }; > + > + &cbass_mcu { > + /* For modules within MCU domain, use mcu UDMAP */ > + dma-domain-controller = <&mcu_udmap>; perhaps add the example of main_udmap and mcu_udmap as well > + }; > +... > -- > Peter > > Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. > Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki -- ~Vinod
