Re: [PATCH V4 6/6] iommu/arm-smmu: Add support for qcom,msm8996-smmu-v2 clocks

From: Vivek Gautam <vivek.gautam@codeaurora.org>
To: Rob Herring <robh@kernel.org>
Cc: joro@8bytes.org, robin.murphy@arm.com,
	Mark Rutland <mark.rutland@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Stephen Boyd <sboyd@codeaurora.org>,
	robdclark@gmail.com, iommu@lists.linux-foundation.org,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	linux-clk@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	sricharan@codeaurora.org,
	Stanimir Varbanov <stanimir.varbanov@linaro.org>,
	architt@codeaurora.org,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH V4 6/6] iommu/arm-smmu: Add support for qcom,msm8996-smmu-v2 clocks
Date: Mon, 10 Jul 2017 12:12:29 +0530	[thread overview]
Message-ID: <CAFp+6iFX=DDcK4DUC_U9h5cBa0Y1==3WKy3X6WXiQZSQ7_BNLg@mail.gmail.com> (raw)
In-Reply-To: <20170710034057.o5tha22rlllbxu3y@rob-hp-laptop>

Hi Rob,

On Mon, Jul 10, 2017 at 9:10 AM, Rob Herring <robh@kernel.org> wrote:
> On Thu, Jul 06, 2017 at 03:07:05PM +0530, Vivek Gautam wrote:
>> qcom,msm8996-smmu-v2 is an arm,smmu-v2 implementation with
>> specific clock and power requirements. This smmu core is used
>> with multiple masters on msm8996, viz. mdss, video, etc.
>> Add bindings for the same.
>>
>> Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
>> ---
>>  Documentation/devicetree/bindings/iommu/arm,smmu.txt | 18 ++++++++++++++++++
>>  drivers/iommu/arm-smmu.c                             | 13 +++++++++++++
>>  2 files changed, 31 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
>> index 00331752d355..5d8e79775fae 100644
>> --- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt
>> +++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
>> @@ -17,6 +17,7 @@ conditions.
>>                          "arm,mmu-401"
>>                          "arm,mmu-500"
>>                          "cavium,smmu-v2"
>> +                        "qcom,msm8996-smmu-v2"
>>
>>                    depending on the particular implementation and/or the
>>                    version of the architecture implemented.
>> @@ -74,11 +75,16 @@ conditions.
>>  - clock-names:    Should be "tcu" and "iface" for "arm,mmu-400",
>>                    "arm,mmu-401" and "arm,mmu-500"
>>
>> +                  Should be "bus", and "iface" for "qcom,msm8996-smmu-v2"
>> +                  implementation.
>> +
>>                    "tcu" clock is required for smmu's register access using the
>>                    programming interface and ptw for downstream bus access. This
>>                    clock is also used for access to the TBU connected to the
>>                    master locally. Sometimes however, TBU is clocked along with
>>                    the master.
>> +                  "bus" clock for "qcom,msm8996-smmu-v2" is requierd for downstream
>
> s/requierd/required/

sure, will correct it.

>
>> +                  bus access and for the smmu ptw.
>>
>>                    "iface" clock is required to access the TCU's programming
>>                    interface, apart from the "tcu" clock.
>> @@ -161,3 +167,15 @@ conditions.
>>                  iommu-map = <0 &smmu3 0 0x400>;
>>                  ...
>>          };
>> +
>> +     /* Qcom's arm,smmu-v2 implementation for msm8996 */
>> +     smmu4: iommu {
>> +             compatible = "qcom,msm8996-smmu-v2";
>
> No registers?

It does have registers. Will add the complete binding example.

Thank you for the review.

Best Regards
Vivek

[snip]

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