From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [Patch v15 4/5] dt-bindings: arm-smmu: Add bindings for qcom,smmu-v2 Date: Tue, 28 Aug 2018 15:34:18 -0500 Message-ID: <20180828203418.GA18366@bogus> References: <20180827105551.16346-1-vivek.gautam@codeaurora.org> <20180827105551.16346-5-vivek.gautam@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20180827105551.16346-5-vivek.gautam@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org To: Vivek Gautam Cc: joro@8bytes.org, robin.murphy@arm.com, will.deacon@arm.com, iommu@lists.linux-foundation.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, freedreno@lists.freedesktop.org, alex.williamson@redhat.com, mark.rutland@arm.com, rjw@rjwysocki.net, robdclark@gmail.com, andy.gross@linaro.org, linux-pm@vger.kernel.org, sboyd@kernel.org, tfiga@chromium.org, jcrouse@codeaurora.org, sricharan@codeaurora.org, m.szyprowski@samsung.com, architt@codeaurora.org, linux-arm-msm@vger.kernel.org List-Id: devicetree@vger.kernel.org On Mon, Aug 27, 2018 at 04:25:50PM +0530, Vivek Gautam wrote: > Add bindings doc for Qcom's smmu-v2 implementation. > > Signed-off-by: Vivek Gautam > Reviewed-by: Tomasz Figa > Tested-by: Srinivas Kandagatla > --- > > Changes since v14: > - This is a new patch added in v15 after noticing the new > checkpatch warning for separate dt-bindings doc. > - This patch also addresses comments given by Rob and Robin to add > a list of valid values of '' in "qcom,-smmu-v2" > compatible string. > > .../devicetree/bindings/iommu/arm,smmu.txt | 47 ++++++++++++++++++++++ > 1 file changed, 47 insertions(+) > > diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt > index 8a6ffce12af5..52198a539606 100644 > --- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt > +++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt > @@ -17,10 +17,24 @@ conditions. > "arm,mmu-401" > "arm,mmu-500" > "cavium,smmu-v2" > + "qcom,-smmu-v2", "qcom,smmu-v2" The v2 in the compatible string is kind of redundant unless the SoC has other SMMU types. > > depending on the particular implementation and/or the > version of the architecture implemented. > > + A number of Qcom SoCs use qcom,smmu-v2 version of the IP. > + "qcom,-smmu-v2" represents a soc specific compatible > + string that should be present along with the "qcom,smmu-v2" > + to facilitate SoC specific clocks/power connections and to > + address specific bug fixes. > + '' string in "qcom,-smmu-v2" should be one of the > + following: > + msm8996 - for msm8996 Qcom SoC. > + sdm845 - for sdm845 Qcom Soc. Rather than all this prose, it would be simpler to just add 2 lines with the full compatibles rather than . The thing is not going to work when/if we move bindings to json-schema also. > + > + An example string would be - > + "qcom,msm8996-smmu-v2", "qcom,smmu-v2". > + > - reg : Base address and size of the SMMU. > > - #global-interrupts : The number of global interrupts exposed by the > @@ -71,6 +85,22 @@ conditions. > or using stream matching with #iommu-cells = <2>, and > may be ignored if present in such cases. > > +- clock-names: List of the names of clocks input to the device. The > + required list depends on particular implementation and > + is as follows: > + - for "qcom,smmu-v2": > + - "bus": clock required for downstream bus access and > + for the smmu ptw, > + - "iface": clock required to access smmu's registers > + through the TCU's programming interface. > + - unspecified for other implementations. > + > +- clocks: Specifiers for all clocks listed in the clock-names property, > + as per generic clock bindings. > + > +- power-domains: Specifiers for power domains required to be powered on for > + the SMMU to operate, as per generic power domain bindings. > + > ** Deprecated properties: > > - mmu-masters (deprecated in favour of the generic "iommus" binding) : > @@ -137,3 +167,20 @@ conditions. > iommu-map = <0 &smmu3 0 0x400>; > ... > }; > + > + /* Qcom's arm,smmu-v2 implementation */ > + smmu4: iommu { Needs a unit-address. > + compatible = "qcom,msm8996-smmu-v2", "qcom,smmu-v2"; > + reg = <0xd00000 0x10000>; > + > + #global-interrupts = <1>; > + interrupts = , > + , > + ; > + #iommu-cells = <1>; > + power-domains = <&mmcc MDSS_GDSC>; > + > + clocks = <&mmcc SMMU_MDP_AXI_CLK>, > + <&mmcc SMMU_MDP_AHB_CLK>; > + clock-names = "bus", "iface"; > + }; > -- > QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member > of Code Aurora Forum, hosted by The Linux Foundation >