| Message ID | 20220706145222.1565238-3-dmitry.baryshkov@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | dt-bindings: display/msm: schema fixes for gpu, gmu and mdp4 | expand |
On 06/07/2022 16:52, Dmitry Baryshkov wrote: > The DT binding desribes using amd,imageon only for Imageon 2xx GPUs. We > have been using amd,imageon with newer (Adreno) GPUs to describe the > headless setup, when the platform does not (yet) have the display DT Does not have "yet"? So later it will have and you drop a compatible? > nodes (and no display support). Document this trick in the schema. > > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > --- > Documentation/devicetree/bindings/display/msm/gpu.yaml | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/Documentation/devicetree/bindings/display/msm/gpu.yaml b/Documentation/devicetree/bindings/display/msm/gpu.yaml > index 346aabdccf7b..e006da95462c 100644 > --- a/Documentation/devicetree/bindings/display/msm/gpu.yaml > +++ b/Documentation/devicetree/bindings/display/msm/gpu.yaml > @@ -16,9 +16,13 @@ properties: > - description: | > The driver is parsing the compat string for Adreno to > figure out the gpu-id and patch level. > + Optional amd,imageon compatibility string enables using Adreno > + without the display node. > items: > - pattern: '^qcom,adreno-[3-6][0-9][0-9]\.[0-9]$' > - const: qcom,adreno > + - const: amd,imageon > + minItems: 2 This is too unspecific. You allow any device to be and not to be compatible with amd,imageon. > - description: | > The driver is parsing the compat string for Imageon to > figure out the gpu-id and patch level. > @@ -148,6 +152,8 @@ allOf: > description: GPU 3D engine clock > - const: rbbmtimer > description: GPU RBBM Timer for Adreno 5xx series > + - const: rbcpr > + description: GPU RB CPR clock > minItems: 2 > maxItems: 7 Do 8 items work with maxItems:7? Best regards, Krzysztof
On 06/07/2022 18:50, Krzysztof Kozlowski wrote: > On 06/07/2022 16:52, Dmitry Baryshkov wrote: >> The DT binding desribes using amd,imageon only for Imageon 2xx GPUs. We >> have been using amd,imageon with newer (Adreno) GPUs to describe the >> headless setup, when the platform does not (yet) have the display DT > > Does not have "yet"? So later it will have and you drop a compatible? Yes. For example see the arch/arm64/boot/dts/qcom/8150.dtsi, which currently has only GPU node. Once we add MDSS/DPU/DSI/etc. nodes, we are going to drop the compat string. > >> nodes (and no display support). Document this trick in the schema. >> >> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> >> --- >> Documentation/devicetree/bindings/display/msm/gpu.yaml | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/display/msm/gpu.yaml b/Documentation/devicetree/bindings/display/msm/gpu.yaml >> index 346aabdccf7b..e006da95462c 100644 >> --- a/Documentation/devicetree/bindings/display/msm/gpu.yaml >> +++ b/Documentation/devicetree/bindings/display/msm/gpu.yaml >> @@ -16,9 +16,13 @@ properties: >> - description: | >> The driver is parsing the compat string for Adreno to >> figure out the gpu-id and patch level. >> + Optional amd,imageon compatibility string enables using Adreno >> + without the display node. >> items: >> - pattern: '^qcom,adreno-[3-6][0-9][0-9]\.[0-9]$' >> - const: qcom,adreno >> + - const: amd,imageon >> + minItems: 2 > > This is too unspecific. You allow any device to be and not to be > compatible with amd,imageon. Yes, this is expected (kind of). Would you have any alternatives/suggestions? > >> - description: | >> The driver is parsing the compat string for Imageon to >> figure out the gpu-id and patch level. >> @@ -148,6 +152,8 @@ allOf: >> description: GPU 3D engine clock >> - const: rbbmtimer >> description: GPU RBBM Timer for Adreno 5xx series >> + - const: rbcpr >> + description: GPU RB CPR clock >> minItems: 2 >> maxItems: 7 > > Do 8 items work with maxItems:7? You would have guessed, yes, they do.
On 06/07/2022 18:00, Dmitry Baryshkov wrote: > On 06/07/2022 18:50, Krzysztof Kozlowski wrote: >> On 06/07/2022 16:52, Dmitry Baryshkov wrote: >>> The DT binding desribes using amd,imageon only for Imageon 2xx GPUs. We >>> have been using amd,imageon with newer (Adreno) GPUs to describe the >>> headless setup, when the platform does not (yet) have the display DT >> >> Does not have "yet"? So later it will have and you drop a compatible? > > Yes. For example see the arch/arm64/boot/dts/qcom/8150.dtsi, which > currently has only GPU node. Once we add MDSS/DPU/DSI/etc. nodes, we are > going to drop the compat string. > >> >>> nodes (and no display support). Document this trick in the schema. >>> >>> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> >>> --- >>> Documentation/devicetree/bindings/display/msm/gpu.yaml | 6 ++++++ >>> 1 file changed, 6 insertions(+) >>> >>> diff --git a/Documentation/devicetree/bindings/display/msm/gpu.yaml b/Documentation/devicetree/bindings/display/msm/gpu.yaml >>> index 346aabdccf7b..e006da95462c 100644 >>> --- a/Documentation/devicetree/bindings/display/msm/gpu.yaml >>> +++ b/Documentation/devicetree/bindings/display/msm/gpu.yaml >>> @@ -16,9 +16,13 @@ properties: >>> - description: | >>> The driver is parsing the compat string for Adreno to >>> figure out the gpu-id and patch level. >>> + Optional amd,imageon compatibility string enables using Adreno >>> + without the display node. >>> items: >>> - pattern: '^qcom,adreno-[3-6][0-9][0-9]\.[0-9]$' >>> - const: qcom,adreno >>> + - const: amd,imageon >>> + minItems: 2 >> >> This is too unspecific. You allow any device to be and not to be >> compatible with amd,imageon. > > Yes, this is expected (kind of). Would you have any > alternatives/suggestions? Using compatible for this kind of breaks the entire idea behind compatibles, because the device does not stop being compatible with amd,imageon. Either it is or it is not. I would understand that drop the compatible per boards which physically do not have display, physically are headless. But the comment in sm8250: "make sure to remove it when display node is added" is just confusing. The typical solution would be to just check the properties of the device and choose different mode if display is missing (via port graph or some other way how the gpu is actually linked to the display). Best regards, Krzysztof
On 06/07/2022 19:19, Krzysztof Kozlowski wrote: > On 06/07/2022 18:00, Dmitry Baryshkov wrote: >> On 06/07/2022 18:50, Krzysztof Kozlowski wrote: >>> On 06/07/2022 16:52, Dmitry Baryshkov wrote: >>>> The DT binding desribes using amd,imageon only for Imageon 2xx GPUs. We >>>> have been using amd,imageon with newer (Adreno) GPUs to describe the >>>> headless setup, when the platform does not (yet) have the display DT >>> >>> Does not have "yet"? So later it will have and you drop a compatible? >> >> Yes. For example see the arch/arm64/boot/dts/qcom/8150.dtsi, which >> currently has only GPU node. Once we add MDSS/DPU/DSI/etc. nodes, we are >> going to drop the compat string. >> >>> >>>> nodes (and no display support). Document this trick in the schema. >>>> >>>> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> >>>> --- >>>> Documentation/devicetree/bindings/display/msm/gpu.yaml | 6 ++++++ >>>> 1 file changed, 6 insertions(+) >>>> >>>> diff --git a/Documentation/devicetree/bindings/display/msm/gpu.yaml b/Documentation/devicetree/bindings/display/msm/gpu.yaml >>>> index 346aabdccf7b..e006da95462c 100644 >>>> --- a/Documentation/devicetree/bindings/display/msm/gpu.yaml >>>> +++ b/Documentation/devicetree/bindings/display/msm/gpu.yaml >>>> @@ -16,9 +16,13 @@ properties: >>>> - description: | >>>> The driver is parsing the compat string for Adreno to >>>> figure out the gpu-id and patch level. >>>> + Optional amd,imageon compatibility string enables using Adreno >>>> + without the display node. >>>> items: >>>> - pattern: '^qcom,adreno-[3-6][0-9][0-9]\.[0-9]$' >>>> - const: qcom,adreno >>>> + - const: amd,imageon >>>> + minItems: 2 >>> >>> This is too unspecific. You allow any device to be and not to be >>> compatible with amd,imageon. >> >> Yes, this is expected (kind of). Would you have any >> alternatives/suggestions? > > Using compatible for this kind of breaks the entire idea behind > compatibles, because the device does not stop being compatible with > amd,imageon. Either it is or it is not. I would understand that drop the > compatible per boards which physically do not have display, physically > are headless. But the comment in sm8250: > "make sure to remove it when display node is added" > is just confusing. > > The typical solution would be to just check the properties of the device > and choose different mode if display is missing (via port graph or some > other way how the gpu is actually linked to the display). The problem is that the gpu doesn't get linked to the display per se. On imx5 platforms the GPU (compatible with amd,imageon) is a standalone device. On qcom platforms the GPU (qcom,adreno) is used as a component in multi-component device. By enlisting qmd,imageon for newer Adreno devices we just enforce non-standard probing sequence, because all other components just do not exist. So, yes, this is hack around compatibles. However probably the only viable alternative around it would be to check in probe path if there is any device node compatible with "qcom,foo-mdss".
diff --git a/Documentation/devicetree/bindings/display/msm/gpu.yaml b/Documentation/devicetree/bindings/display/msm/gpu.yaml index 346aabdccf7b..e006da95462c 100644 --- a/Documentation/devicetree/bindings/display/msm/gpu.yaml +++ b/Documentation/devicetree/bindings/display/msm/gpu.yaml @@ -16,9 +16,13 @@ properties: - description: | The driver is parsing the compat string for Adreno to figure out the gpu-id and patch level. + Optional amd,imageon compatibility string enables using Adreno + without the display node. items: - pattern: '^qcom,adreno-[3-6][0-9][0-9]\.[0-9]$' - const: qcom,adreno + - const: amd,imageon + minItems: 2 - description: | The driver is parsing the compat string for Imageon to figure out the gpu-id and patch level. @@ -148,6 +152,8 @@ allOf: description: GPU 3D engine clock - const: rbbmtimer description: GPU RBBM Timer for Adreno 5xx series + - const: rbcpr + description: GPU RB CPR clock minItems: 2 maxItems: 7
The DT binding desribes using amd,imageon only for Imageon 2xx GPUs. We have been using amd,imageon with newer (Adreno) GPUs to describe the headless setup, when the platform does not (yet) have the display DT nodes (and no display support). Document this trick in the schema. Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> --- Documentation/devicetree/bindings/display/msm/gpu.yaml | 6 ++++++ 1 file changed, 6 insertions(+)