Messages in this thread | | | From | Anson Huang <> | Subject | RE: [PATCH 3/3] cpufreq: imx-sc: add i.mx system controller cpufreq support | Date | Wed, 13 Feb 2019 08:46:45 +0000 |
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Hi, Viresh
Best Regards! Anson Huang
> -----Original Message----- > From: Viresh Kumar [mailto:viresh.kumar@linaro.org] > Sent: 2019年2月13日 15:09 > To: Anson Huang <anson.huang@nxp.com> > Cc: robh+dt@kernel.org; mark.rutland@arm.com; shawnguo@kernel.org; > s.hauer@pengutronix.de; kernel@pengutronix.de; festevam@gmail.com; > catalin.marinas@arm.com; will.deacon@arm.com; rjw@rjwysocki.net; > Aisheng Dong <aisheng.dong@nxp.com>; Daniel Baluta > <daniel.baluta@nxp.com>; Andy Gross <andy.gross@linaro.org>; > horms+renesas@verge.net.au; heiko@sntech.de; arnd@arndb.de; > bjorn.andersson@linaro.org; jagan@amarulasolutions.com; > enric.balletbo@collabora.com; marc.w.gonzalez@free.fr; olof@lixom.net; > devicetree@vger.kernel.org; linux-arm-kernel@lists.infradead.org; linux- > kernel@vger.kernel.org; linux-pm@vger.kernel.org; dl-linux-imx <linux- > imx@nxp.com> > Subject: Re: [PATCH 3/3] cpufreq: imx-sc: add i.mx system controller cpufreq > support > > On 13-02-19, 03:09, Anson Huang wrote: > > On NXP's i.MX SoCs with system controller inside, CPU frequency > > scaling can ONLY be done by system controller firmware, and it can > > ONLY be requested from secure mode, so Linux cpufreq driver has to > > call ARM SMC to trap to ARM-Trusted-Firmware to request system > > controller firmware to do CPU frequency scaling. > > > > This patch adds i.MX system controller cpufreq driver support, when > > doing CPU frequency scaling, cpufreq driver will do ARM SMC call and > > trap to ARM-Trusted-Firmware, then SIP(silicon provider) service will > > communicate with system controller for CPU frequenct scaling. > > > > Signed-off-by: Anson Huang <Anson.Huang@nxp.com> > > --- > > drivers/cpufreq/Kconfig.arm | 9 ++ > > drivers/cpufreq/Makefile | 1 + > > drivers/cpufreq/imx-sc-cpufreq.c | 183 > > +++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 193 insertions(+) > > create mode 100644 drivers/cpufreq/imx-sc-cpufreq.c > > Why can't you use cpufreq-dt driver like everyone else ?
Just notice that we can overwrite the set_target if using cpufreq-dt, then we still need a platform cpufreq file to implement arch_set_freq_scale(), I can use it to save the code of imx system controller cpufreq driver, and BTW, can cpufreq-dt support multi clusters cpufreq? As i.MX8QM has 2 clusters running with different OPPs.
Thanks, Anson.
> > -- > viresh
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