DT binding for staging vchiq

[Sergey Suloev]

Stefan, thank you so much for detailed answer.


On 01/17/2018 09:48 PM, Stefan Wahren wrote:
> Hi Sergey,
>
>> Sergey Suloev <ssuloev at orpaltech.com> hat am 17. Januar 2018 um 14:45 geschrieben:
>>
>>
>> Hello everyone,
>>
>> I am trying to use RPi3  VC4 gpu with Qt5 quick/qml. When I run my
>> application Qt5 is always complaining about missing vchiq device in the
>> system. I know there is vchiq driver available in staging.
>>
>> My questions are:
>>
>> 1) What is the current status of the driver ? Is it working at all?
>  From my point of view it's still experimental. It's mostly the same driver as in downstream, but its function highly dependents on the configuration:
>
> arm/bcm2835_defconfig = should work
> arm/multi_v7_defconfig = may work
> arm64/defconfig = won't work [1]
>
> In order to the function of the driver use vchiq_test from the Raspberry Pi userland.
>
> Btw testers are always welcome :-)
>
>> can it be used with Qt5 ?
> If your application works with the downstream kernel, there is a high chance.
>
>> 2) Can I have a working example of DT binding for the driver ?
> This is one of my many TODOs [2] to provide a binding document. Please try the following old patch. The cache-line-size depends on the used SoC (BCM2835 = 32, BCM2836/BCM2837 = 64).
>
> Good luck
>
> diff --git a/arch/arm/boot/dts/bcm2835-rpi.dtsi b/arch/arm/boot/dts/bcm2835-rpi.dtsi
> index e55b362..7398b96 100644
> --- a/arch/arm/boot/dts/bcm2835-rpi.dtsi
> +++ b/arch/arm/boot/dts/bcm2835-rpi.dtsi
> @@ -27,6 +27,14 @@
>                          firmware = <&firmware>;
>                          #power-domain-cells = <1>;
>                  };
> +
> +               vchiq: vchiq {
> +                       compatible = "brcm,bcm2835-vchiq";
> +                       reg = <0x7e00b840 0xf>;
> +                       interrupts = <0 2>;
> +                       cache-line-size = <64>;
> +                       firmware = <&firmware>;
> +		};
>          };
>   };
>
>
> [1] - https://github.com/lategoodbye/rpi-zero/issues/23
> [2] - https://github.com/lategoodbye/rpi-zero/issues/8
>
>> Thanks
>>
>>
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