Re: [PATCH v4 1/6] clk: imx8m: Set CLK_GET_RATE_NOCACHE on dram clocks

From: Abel Vesa <abel.vesa@nxp.com>
To: Leonard Crestez <leonard.crestez@nxp.com>
Cc: "Stephen Boyd" <sboyd@kernel.org>,
	"MyungJoo Ham" <myungjoo.ham@samsung.com>,
	"Kyungmin Park" <kyungmin.park@samsung.com>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	"Shawn Guo" <shawnguo@kernel.org>,
	"Chanwoo Choi" <cw00.choi@samsung.com>,
	"Mark Rutland" <mark.rutland@arm.com>,
	"Michael Turquette" <mturquette@baylibre.com>,
	"Artur Świgoń" <a.swigon@partner.samsung.com>,
	"Saravana Kannan" <saravanak@google.com>,
	"Angus Ainslie" <angus@akkea.ca>,
	"Martin Kepplinger" <martink@posteo.de>,
	"Matthias Kaehlcke" <mka@chromium.org>,
	"Krzysztof Kozlowski" <krzk@kernel.org>,
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	"Georgi Djakov" <georgi.djakov@linaro.org>,
	"Aisheng Dong" <aisheng.dong@nxp.com>,
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	"Fabio Estevam" <fabio.estevam@nxp.com>,
	"Viresh Kumar" <viresh.kumar@linaro.org>,
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	"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
	"linux-clk@vger.kernel.org" <linux-clk@vger.kernel.org>,
	dl-linux-imx <linux-imx@nxp.com>,
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	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v4 1/6] clk: imx8m: Set CLK_GET_RATE_NOCACHE on dram clocks
Date: Tue, 12 Nov 2019 15:10:09 +0000	[thread overview]
Message-ID: <20191112151008.5spfh7y5xzppk4s5@fsr-ub1664-175> (raw)
In-Reply-To: <VI1PR04MB702387DCA9DB5A0A3F6288EDEE770@VI1PR04MB7023.eurprd04.prod.outlook.com>

On 19-11-12 13:43:35, Leonard Crestez wrote:
> On 12.11.2019 13:18, Abel Vesa wrote:
> > On 19-11-09 00:39:51, Leonard Crestez wrote:
> >> These clocks are only modified as part of DRAM frequency switches during
> >> which DRAM itself is briefly inaccessible. The switch is performed with
> >> a SMC call to by TF-A which runs from a SRAM area; upon returning to
> >> linux several clocks bits are modified and we need to update them.
> >>
> >> For rate bits an easy solution is to just mark with
> >> CLK_GET_RATE_NOCACHE so that new rates are always read back from
> >> registers.
> >>
> >> Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
> >> ---
> >>   drivers/clk/imx/clk-imx8mm.c | 11 +++++++++--
> >>   drivers/clk/imx/clk-imx8mn.c | 12 ++++++++++--
> >>   drivers/clk/imx/clk-imx8mq.c | 15 +++++++++++----
> >>   3 files changed, 30 insertions(+), 8 deletions(-)
> 
> >> --- a/drivers/clk/imx/clk-imx8mn.c
> >> +++ b/drivers/clk/imx/clk-imx8mn.c
> >> @@ -428,12 +428,20 @@ static int imx8mn_clocks_probe(struct platform_device *pdev)
> >>   	clks[IMX8MN_CLK_AHB] = imx8m_clk_composite_critical("ahb", imx8mn_ahb_sels, base + 0x9000);
> >>   	clks[IMX8MN_CLK_AUDIO_AHB] = imx8m_clk_composite("audio_ahb", imx8mn_audio_ahb_sels, base + 0x9100);
> >>   	clks[IMX8MN_CLK_IPG_ROOT] = imx_clk_divider2("ipg_root", "ahb", base + 0x9080, 0, 1);
> >>   	clks[IMX8MN_CLK_IPG_AUDIO_ROOT] = imx_clk_divider2("ipg_audio_root", "audio_ahb", base + 0x9180, 0, 1);
> >>   	clks[IMX8MN_CLK_DRAM_CORE] = imx_clk_mux2_flags("dram_core_clk", base + 0x9800, 24, 1, imx8mn_dram_core_sels, ARRAY_SIZE(imx8mn_dram_core_sels), CLK_IS_CRITICAL);
> >> -	clks[IMX8MN_CLK_DRAM_ALT] = imx8m_clk_composite("dram_alt", imx8mn_dram_alt_sels, base + 0xa000);
> >> -	clks[IMX8MN_CLK_DRAM_APB] = imx8m_clk_composite_critical("dram_apb", imx8mn_dram_apb_sels, base + 0xa080);
> >> +
> >> +	/*
> >> +	 * DRAM clocks are manipulated from TF-A outside clock framework.
> >> +	 * Mark with GET_RATE_NOCACHE to always read div value from hardware
> >> +	 */
> >> +	clks[IMX8MN_CLK_DRAM_ALT] = __imx8m_clk_composite("dram_alt", imx8mn_dram_alt_sels, base + 0xa000,
> >> +			CLK_GET_RATE_NOCACHE);
> >> +	clks[IMX8MN_CLK_DRAM_APB] = __imx8m_clk_composite("dram_apb", imx8mn_dram_apb_sels, base + 0xa080,
> >> +			CLK_IS_CRITICAL | CLK_GET_RATE_NOCACHE);
> > 
> > nitpick: I think it looks better if we stick to one line each clock.
> > I know it's against the 80 chars rule, but at least is consistent.
> 
> Yes, there are longer lines in the imx8m* files anyway.
> 
> If I fix this (in all instances) can I also add a "reviewed-by"?
> 

Sorry, I forgot to add the line.

For all the clock related changes:

Reviewed-by: Abel Vesa <abel.vesa@nxp.com>

> --
> Regards,
> Leonard