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Subject: Re: [PATCH v6 08/52] dt-bindings: memory: tegra20: emc: Document
 mfd-simple compatible and statistics sub-device
To:     Thierry Reding <thierry.reding@gmail.com>
Cc:     Jonathan Hunter <jonathanh@nvidia.com>,
        Georgi Djakov <georgi.djakov@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Peter De Schrijver <pdeschrijver@nvidia.com>,
        MyungJoo Ham <myungjoo.ham@samsung.com>,
        Kyungmin Park <kyungmin.park@samsung.com>,
        Chanwoo Choi <cw00.choi@samsung.com>,
        Mikko Perttunen <cyndis@kapsi.fi>,
        Viresh Kumar <vireshk@kernel.org>,
        Peter Geis <pgwipeout@gmail.com>,
        Nicolas Chauvet <kwizart@gmail.com>,
        Krzysztof Kozlowski <krzk@kernel.org>,
        linux-tegra@vger.kernel.org, linux-pm@vger.kernel.org,
        linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        devicetree@vger.kernel.org
References: <20201025221735.3062-1-digetx@gmail.com>
 <20201025221735.3062-9-digetx@gmail.com> <20201027132241.GG1822510@ulmo>
From:   Dmitry Osipenko <digetx@gmail.com>
Message-ID: <0a619270-b301-4eeb-6216-0ad5fed6a20a@gmail.com>
Date:   Tue, 27 Oct 2020 22:23:22 +0300
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27.10.2020 16:22, Thierry Reding пишет:
> On Mon, Oct 26, 2020 at 01:16:51AM +0300, Dmitry Osipenko wrote:
>> External Memory Controller can gather various hardware statistics that
>> are intended to be used for debugging purposes and for dynamic frequency
>> scaling of memory bus.
>>
>> Document the new mfd-simple compatible and EMC statistics sub-device.
>> The subdev contains EMC DFS OPP table and interconnect paths to be used
>> for dynamic scaling of system's memory bandwidth based on EMC utilization
>> statistics.
>>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>> ---
>>  .../memory-controllers/nvidia,tegra20-emc.txt | 43 +++++++++++++++++--
>>  1 file changed, 40 insertions(+), 3 deletions(-)
> 
> Why does this have to be modelled as a separate device? Isn't this just
> using a couple of registers out of the EMC register range? If so, this
> would better just be integrated into the parent node and implemented as
> part of the EMC driver. No need to further complicate things by adding
> a dummy child.

Maybe true, I'll take a closer look.