On Wed, Feb 22, 2017 at 3:25 AM, Stanimir Varbanov <stanimir.varbanov@xxxxxxxxxx> wrote: > Hi Rob, > > On 02/22/2017 02:09 AM, Rob Herring wrote: >> On Tue, Feb 07, 2017 at 03:10:17PM +0200, Stanimir Varbanov wrote: >>> Add binding document for Venus video encoder/decoder driver >>> >>> Cc: Rob Herring <robh+dt@xxxxxxxxxx> >>> Cc: devicetree@xxxxxxxxxxxxxxx >>> Signed-off-by: Stanimir Varbanov <stanimir.varbanov@xxxxxxxxxx> >>> --- >>> Changes since previous v5: >>> * dropped rproc phandle (remoteproc is not used anymore) >>> * added subnodes paragraph with descrition of three subnodes: >>> - video-decoder and video-encoder - describes decoder (core0) and >>> encoder (core1) power-domains and clocks (applicable for msm8996 >>> Venus core). >>> - video-firmware - needed to get reserved memory region where the >>> firmware is stored. >>> >>> .../devicetree/bindings/media/qcom,venus.txt | 112 +++++++++++++++++++++ >>> 1 file changed, 112 insertions(+) >>> create mode 100644 Documentation/devicetree/bindings/media/qcom,venus.txt >>> >>> diff --git a/Documentation/devicetree/bindings/media/qcom,venus.txt b/Documentation/devicetree/bindings/media/qcom,venus.txt >>> new file mode 100644 >>> index 000000000000..4427af3ca5a5 >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/media/qcom,venus.txt >>> @@ -0,0 +1,112 @@ >> >> [...] >> >>> +* Subnodes >>> +The Venus node must contain three subnodes representing video-decoder, >>> +video-encoder and video-firmware. >> >> [...] >> >>> +The video-firmware subnode should contain: >>> + >>> +- memory-region: >>> + Usage: required >>> + Value type: <phandle> >>> + Definition: reference to the reserved-memory for the memory region >>> + >>> +* An Example >>> + video-codec@1d00000 { >>> + compatible = "qcom,msm8916-venus"; >>> + reg = <0x01d00000 0xff000>; >>> + interrupts = <GIC_SPI 44 IRQ_TYPE_LEVEL_HIGH>; >>> + clocks = <&gcc GCC_VENUS0_VCODEC0_CLK>, >>> + <&gcc GCC_VENUS0_AHB_CLK>, >>> + <&gcc GCC_VENUS0_AXI_CLK>; >>> + clock-names = "core", "iface", "bus"; >>> + power-domains = <&gcc VENUS_GDSC>; >>> + iommus = <&apps_iommu 5>; >>> + >>> + video-decoder { >>> + compatible = "venus-decoder"; >>> + clocks = <&mmcc VIDEO_SUBCORE0_CLK>; >>> + clock-names = "core"; >>> + power-domains = <&mmcc VENUS_CORE0_GDSC>; >>> + }; >>> + >>> + video-encoder { >>> + compatible = "venus-encoder"; >>> + clocks = <&mmcc VIDEO_SUBCORE1_CLK>; >>> + clock-names = "core"; >>> + power-domains = <&mmcc VENUS_CORE1_GDSC>; >>> + }; >>> + >>> + video-firmware { >>> + memory-region = <&venus_mem>; >> >> Why does this need to be a sub node? > > Because firmware reserved memory region must have separate struct > device, otherwise allocating video buffers (and map them through iommu) > for video-codec will fail because dma_alloc_coherent trying to allocate > from per-device coherent area. Why can't the struct device be the video-codec device? Looking at the code, I don't see why you need the 2nd struct device. In any case, this is letting the driver design the binding which is wrong. From a binding perspective, there's no reason to have this node. Rob -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html