From: Shawn Guo <shawnguo@kernel.org>
To: Leonard Crestez <leonard.crestez@nxp.com>
Cc: "Mark Rutland" <mark.rutland@arm.com>,
"Artur Świgoń" <a.swigon@partner.samsung.com>,
"Jacky Bai" <ping.bai@nxp.com>,
"Viresh Kumar" <viresh.kumar@linaro.org>,
"Michael Turquette" <mturquette@baylibre.com>,
"Angus Ainslie" <angus@akkea.ca>,
"Alexandre Bailon" <abailon@baylibre.com>,
"Matthias Kaehlcke" <mka@chromium.org>,
"Abel Vesa" <abel.vesa@nxp.com>,
"Saravana Kannan" <saravanak@google.com>,
"Krzysztof Kozlowski" <krzk@kernel.org>,
"linux-clk@vger.kernel.org" <linux-clk@vger.kernel.org>,
"Chanwoo Choi" <cw00.choi@samsung.com>,
"MyungJoo Ham" <myungjoo.ham@samsung.com>,
dl-linux-imx <linux-imx@nxp.com>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
"Rob Herring" <robh+dt@kernel.org>,
"Martin Kepplinger" <martink@posteo.de>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"Aisheng Dong" <aisheng.dong@nxp.com>,
"Anson Huang" <anson.huang@nxp.com>,
"Stephen Boyd" <sboyd@kernel.org>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
"Kyungmin Park" <kyungmin.park@samsung.com>,
"kernel@pengutronix.de" <kernel@pengutronix.de>,
"Fabio Estevam" <fabio.estevam@nxp.com>,
"Georgi Djakov" <georgi.djakov@linaro.org>
Subject: Re: [PATCH v3 4/6] PM / devfreq: Add dynamic scaling for imx ddr controller
Date: Mon, 2 Dec 2019 21:34:51 +0800 [thread overview]
Message-ID: <20191202133449.GA21897@dragon> (raw)
In-Reply-To: <VI1PR04MB70234400D6CF248C18321FDBEE430@VI1PR04MB7023.eurprd04.prod.outlook.com>
On Mon, Dec 02, 2019 at 09:12:12AM +0000, Leonard Crestez wrote:
> >> +
> >> + /* change the ddr freqency */
> >> + arm_smccc_smc(IMX_SIP_DDR_DVFS, target_freq, online_cpus,
> >> + 0, 0, 0, 0, 0, &res);
> >> +
> >> + local_irq_enable();
> >> +}
> >> +
> >> +struct clk *clk_get_parent_by_index(struct clk *clk, int index)
> >> +{
> >> + struct clk_hw *hw;
> >> +
> >> + hw = clk_hw_get_parent_by_index(__clk_get_hw(clk), index);
> >
> > Okay, this is why you need clk-provider.h. But this
> > clk_get_parent_by_index() function looks completely generic, and should
> > be proposed to clock core?
>
> There are very few driver users of clk_hw_get_parent_by_index:
>
> $ git grep -wl clk_hw_get_parent_by_index |grep -v drivers/clk
> arch/mips/alchemy/common/clock.c
> drivers/cpufreq/qoriq-cpufreq.c
> drivers/devfreq/imx8m-ddrc.c
> drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c
> drivers/gpu/drm/sun4i/sun8i_hdmi_phy_clk.c
> drivers/media/platform/atmel/atmel-isc-base.c
> drivers/rtc/rtc-ac100.c
> include/linux/clk-provider.h
>
> Even clk_get_parent has few users and it contains this strange comment:
>
> /* TODO: Create a per-user clk and change callers to call clk_put */
>
> That proposed change effectively creates a new API? I didn't want to add
> a new clk core API with unclear semantics.
Since the merged version has 'static' added for clk_get_parent_by_index(),
I'm fine with it being a local function. It's Stephen's call whether
we should have it at clock core level.
Shawn
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next prev parent reply other threads:[~2019-12-02 13:35 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-31 21:50 [PATCH v3 0/6] PM / devfreq: Add dynamic scaling for imx ddr controller Leonard Crestez
2019-10-31 21:50 ` [PATCH v3 1/6] clk: imx8m: Set CLK_GET_RATE_NOCACHE on dram clocks Leonard Crestez
2019-12-02 3:12 ` Shawn Guo
2019-12-02 4:19 ` Leonard Crestez
2019-10-31 21:50 ` [PATCH v3 2/6] clk: imx: Mark dram pll on 8mm and 8mn with CLK_GET_RATE_NOCACHE Leonard Crestez
2019-10-31 21:50 ` [PATCH v3 3/6] dt-bindings: devfreq: Add bindings for imx ddr controller Leonard Crestez
2019-11-04 22:21 ` Rob Herring
2019-11-05 19:25 ` Leonard Crestez
2019-11-05 20:13 ` Rob Herring
2019-10-31 21:50 ` [PATCH v3 4/6] PM / devfreq: Add dynamic scaling " Leonard Crestez
2019-12-02 5:38 ` Shawn Guo
2019-12-02 9:12 ` Leonard Crestez
2019-12-02 13:34 ` Shawn Guo [this message]
2019-10-31 21:50 ` [PATCH v3 5/6] PM / devfreq: imx-ddrc: Measure bandwidth with perf Leonard Crestez
2019-10-31 21:50 ` [PATCH v3 6/6] arm64: dts: imx8m: Add ddr controller nodes Leonard Crestez
2019-11-04 22:01 ` Rob Herring
2019-11-11 14:29 ` Leonard Crestez
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