| Message ID | 20230929-wave5_v13_media_master-v13-6-5ac60ccbf2ce@collabora.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v13,1/8] media: v4l2: Add ignore_cap_streaming flag | expand |
On Thu, Oct 12, 2023 at 03:24:12PM +0200, Krzysztof Kozlowski wrote: > On 12/10/2023 13:01, Sebastian Fricke wrote: > > From: Robert Beckett <bob.beckett@collabora.com> > > > > Add bindings for the chips&media wave5 codec driver > > > > Signed-off-by: Robert Beckett <bob.beckett@collabora.com> > > Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com> > > Signed-off-by: Sebastian Fricke <sebastian.fricke@collabora.com> > > --- > > .../devicetree/bindings/media/cnm,wave5.yaml | 60 ++++++++++++++++++++++ > > 1 file changed, 60 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/media/cnm,wave5.yaml b/Documentation/devicetree/bindings/media/cnm,wave5.yaml > > new file mode 100644 > > index 000000000000..b31d34aec05b > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/media/cnm,wave5.yaml > > @@ -0,0 +1,60 @@ > > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) > > +%YAML 1.2 > > +--- > > +$id: http://devicetree.org/schemas/media/cnm,wave5.yaml# > > Filename matching compatible, so: cnm,cm521c-vpu.yaml > > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > + > > +title: Chips&Media Wave 5 Series multi-standard codec IP > > + > > +maintainers: > > + - Nas Chung <nas.chung@chipsnmedia.com> > > + - Jackson Lee <jackson.lee@chipsnmedia.com> > > + > > +description: > > + The Chips&Media WAVE codec IP is a multi format video encoder/decoder > > + > > +properties: > > + compatible: > > + enum: > > + - cnm,cm521c-vpu > > Can this device be anything else? Why VPU suffix? It needs an SoC specific compatible (TI something...) as well (or instead). Unless there's a public spec with details on how many clocks, resets, interrupts, etc. there are. Rob
On 17/10/2023 15:39, Devarsh Thakkar wrote: >> +required: >> + - compatible >> + - reg >> + - clocks >> + - interrupts >> + > > Is it possible to keep interrupts property as optional given HW can still work > without it if SW does polling of ISR using registers? > > The reason to ask is in TI AM62A SoC (which also uses this codec) there is an > SoC errata of missing interrupt line to A53 and we are using SW based polling > locally to run the driver. > > We were planning to upstream that SW based polling support patch in CnM driver > once this base initial driver patch series gets merged, but just wanted to > check if upfront it is possible to have interrupts property as optional so > that we don't have to change the binding doc again to make it optional later on. > > Also note that the polling patch won't be specific to AM62A, other SoC's too > which use this wave5 hardware if they want can enable polling by choice (by > removing interrupt property) > > Could you please share your opinion on this ? You know, if you do not have interrupt line connected, how could it be required, right? If the hardware does not require interrupt to be connected then bindings should not require it. Best regards, Krzysztof
Hey Krzysztof, On 22.10.2023 18:12, Krzysztof Kozlowski wrote: >On 17/10/2023 15:39, Devarsh Thakkar wrote: >>> +required: >>> + - compatible >>> + - reg >>> + - clocks >>> + - interrupts >>> + >> >> Is it possible to keep interrupts property as optional given HW can still work >> without it if SW does polling of ISR using registers? >> >> The reason to ask is in TI AM62A SoC (which also uses this codec) there is an >> SoC errata of missing interrupt line to A53 and we are using SW based polling >> locally to run the driver. >> >> We were planning to upstream that SW based polling support patch in CnM driver >> once this base initial driver patch series gets merged, but just wanted to >> check if upfront it is possible to have interrupts property as optional so >> that we don't have to change the binding doc again to make it optional later on. >> >> Also note that the polling patch won't be specific to AM62A, other SoC's too >> which use this wave5 hardware if they want can enable polling by choice (by >> removing interrupt property) >> >> Could you please share your opinion on this ? > >You know, if you do not have interrupt line connected, how could it be >required, right? If the hardware does not require interrupt to be >connected then bindings should not require it. Alright, so I will make the interrupt optional in the DT binding. By simply removing it from this list: required: - compatible - reg - clocks - interrupts Is it possible to make it required later on for certain SoC by adding something along the lines of: allOf: - if: properties: compatible: contains: enum: - soc_compatible... ... then: properties: interrupts: true ? > >Best regards, >Krzysztof Sincerely, Sebastian > >_______________________________________________ >Kernel mailing list -- kernel@mailman.collabora.com >To unsubscribe send an email to kernel-leave@mailman.collabora.com
diff --git a/Documentation/devicetree/bindings/media/cnm,wave5.yaml b/Documentation/devicetree/bindings/media/cnm,wave5.yaml new file mode 100644 index 000000000000..b31d34aec05b --- /dev/null +++ b/Documentation/devicetree/bindings/media/cnm,wave5.yaml @@ -0,0 +1,60 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/media/cnm,wave5.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Chips&Media Wave 5 Series multi-standard codec IP + +maintainers: + - Nas Chung <nas.chung@chipsnmedia.com> + - Jackson Lee <jackson.lee@chipsnmedia.com> + +description: + The Chips&Media WAVE codec IP is a multi format video encoder/decoder + +properties: + compatible: + enum: + - cnm,cm521c-vpu + + reg: + maxItems: 1 + + clocks: + items: + - description: VCODEC clock + + interrupts: + maxItems: 1 + + power-domains: + maxItems: 1 + + resets: + maxItems: 1 + + sram: + $ref: /schemas/types.yaml#/definitions/phandle + description: + The VPU uses the SRAM to store some of the reference data instead of + storing it on DMA memory. It is mainly used for the purpose of reducing + bandwidth. + +required: + - compatible + - reg + - clocks + - interrupts + +additionalProperties: false + +examples: + - | + vpu: video-codec@12345678 { + compatible = "cnm,cm521c-vpu"; + reg = <0x12345678 0x1000>; + clocks = <&clks 42>; + interrupts = <42>; + sram = <&sram>; + };