On Thu, May 14, 2020 at 10:40:58AM +0200, Lucas Stach wrote: > Am Donnerstag, den 14.05.2020, 09:27 +0100 schrieb Russell King - ARM Linux admin: > > On Thu, May 14, 2020 at 10:18:02AM +0200, Lucas Stach wrote: > > > Am Mittwoch, den 13.05.2020, 23:41 -0300 schrieb Fabio Estevam: > > > > On Wed, May 13, 2020 at 2:09 PM Fabio Estevam <festevam@xxxxxxxxx> wrote: > > > > > > > > > The binding doc Documentation/devicetree/bindings/gpu/vivante,gc.yaml > > > > > says that only the 'reg' clock could be optional, the others are > > > > > required. > > > > > > > > arch/arm/boot/dts/dove.dtsi only uses the 'core' clock. > > > > arch/arm/boot/dts/stm32mp157.dtsi uses 'bus' and 'core' > > > > > > > > Maybe the binding needs to be updated and it seems that using > > > > devm_clk_get_optional() like you propose is safe. > > > > > > The binding is correct as-is. We want to require those clocks to be > > > present, but the dove DT was added before the binding was finalized, so > > > the driver still treats the clocks as optional to not break > > > compatibility with old DTs. Maybe this warrants a comment in the > > > code... > > > > The binding doc in mainline says: > > > > clocks: > > items: > > - description: AXI/master interface clock > > - description: GPU core clock > > - description: Shader clock (only required if GPU has feature PIPE_3D) > > - description: AHB/slave interface clock (only required if GPU can gate slave interface independently) > > minItems: 1 > > maxItems: 4 > > > > clock-names: > > items: > > enum: [ bus, core, shader, reg ] > > minItems: 1 > > maxItems: 4 > > > > which looks correct to me - and means that Dove is compliant with that. > > The YAML binding actually did loose something in translation here, > which I didn't notice. Previously all those clocks were listed under > "Required properties", with the exceptions listed in parenthesis. So > the Dove GPU, which is a combined 2D/3D core should have axi, core and > shader clocks specified. That may be your desire, but that is impossible without knowing that (a) it has the clocks (b) what those clocks are connected to I guess we could "make something up" but as DT is supposed to describe hardware, I don't see how we can satisfy that and your requirement. The only thing that is known from the documentation is that there is one clock for the GPU on Dove. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 10.2Mbps down 587kbps up _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
