From: Stephen Warren <swarren@xxxxxxxxxxxxx> Subject: Re: [PATCH 1/1] arm/dts: Tegra30: Add device tree support for SMMU Date: Fri, 13 Apr 2012 21:33:47 +0200 Message-ID: <4F887F9B.700@xxxxxxxxxxxxx> > On 04/13/2012 04:22 AM, Hiroshi Doyu wrote: > > From: Hiroshi DOYU <hdoyu@xxxxxxxxxx> > > > > Add device tree support for Tegra30 IOMMU(SMMU). > > > +++ b/Documentation/devicetree/bindings/arm/tegra/tegra30-smmu.txt > > I personally like the documentation to be named after the full > compatible value, so nvidia,tegra30-smmu.txt. OK > > @@ -0,0 +1,19 @@ > > +NVIDIA Tegra 30 IOMMU H/W, SMMU (System Memory Management Unit) > > + > > +Required properties: > > +- compatible : "nvidia,tegra30-smmu" > > +- reg : Should contain MC registers location and length > > +- reg : Should contain AHB Arbitration registers and length > > +- reg : Should contain virtual address space range > > This looks like 3 properties with the same name. It seems common to > write something more like: > > reg : Should contain the register address and length for each fo the MC > and AHB arbitration registers. OK, this looks better. > But why does the SMMU driver expect to control the AHB arbitration > registers? They seem unrelated to the SMMU. It's necessary to inform AHB that SMMU is ready to use. There's a dedicated bit for SMMU in this AHB arbitration register. > As I said in my previous email, I think the VA space size should be a > separate property. OK, I'll update. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
