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References: <20231101-gdsc-hwctrl-v3-0-0740ae6b2b04@linaro.org> <20231101-gdsc-hwctrl-v3-1-0740ae6b2b04@linaro.org>
In-Reply-To: <20231101-gdsc-hwctrl-v3-1-0740ae6b2b04@linaro.org>
From:   Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Date:   Wed, 1 Nov 2023 23:26:04 +0200
Message-ID: <CAA8EJpobBJfmztkLoQBmUAbUR16HY0sNZpnA+ZTSmn5VvRWauA@mail.gmail.com>
Subject: Re: [PATCH RESEND v3 1/5] PM: domains: Allow devices attached to
 genpd to be managed by HW
To:     Abel Vesa <abel.vesa@linaro.org>
Cc:     "Rafael J. Wysocki" <rafael@kernel.org>,
        Kevin Hilman <khilman@kernel.org>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Pavel Machek <pavel@ucw.cz>, Len Brown <len.brown@intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Andy Gross <agross@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Stanimir Varbanov <stanimir.k.varbanov@gmail.com>,
        Vikash Garodia <quic_vgarodia@quicinc.com>,
        "Bryan O'Donoghue" <bryan.odonoghue@linaro.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Taniya Das <tdas@qti.qualcomm.com>, linux-pm@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        linux-clk@vger.kernel.org, linux-media@vger.kernel.org
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On Wed, 1 Nov 2023 at 11:08, Abel Vesa <abel.vesa@linaro.org> wrote:
>
> From: Ulf Hansson <ulf.hansson@linaro.org>
>
> Some power-domains may be capable of relying on the HW to control the power
> for a device that's hooked up to it. Typically, for these kinds of
> configurations the device doesn't really need to be attached to a PM domain
> (genpd), from Linux point of view. However, in some cases the behaviour of
> the power-domain and its device can be changed in runtime.
>
> To allow a consumer driver to change the behaviour of the PM domain for its
> device, let's provide a new function, dev_pm_genpd_set_hwmode(). Moreover,
> let's add a corresponding optional genpd callback, ->set_hwmode_dev(),
> which the genpd provider should implement if it can support switching
> between HW controlled mode and SW controlled mode. Similarly, add the
> dev_pm_genpd_get_hwmode() to allow consumers to read the current mode and
> its corresponding optional genpd callback, ->get_hwmode_dev(), which the
> genpd provider can also implement for reading back the mode from the
> hardware.
>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> Signed-off-by: Abel Vesa <abel.vesa@linaro.org>

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

-- 
With best wishes
Dmitry