linux-kernel - Re: [PATCH 3/3] cpufreq: imx-sc: add i.mx system controller cpufreq support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20190213101207.ggunz5lhlv46r5o6@vireshk-i7>
Date:   Wed, 13 Feb 2019 15:42:07 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Anson Huang <anson.huang@....com>
Cc:     "robh+dt@...nel.org" <robh+dt@...nel.org>,
        "mark.rutland@....com" <mark.rutland@....com>,
        "shawnguo@...nel.org" <shawnguo@...nel.org>,
        "s.hauer@...gutronix.de" <s.hauer@...gutronix.de>,
        "kernel@...gutronix.de" <kernel@...gutronix.de>,
        "festevam@...il.com" <festevam@...il.com>,
        "catalin.marinas@....com" <catalin.marinas@....com>,
        "will.deacon@....com" <will.deacon@....com>,
        "rjw@...ysocki.net" <rjw@...ysocki.net>,
        Aisheng Dong <aisheng.dong@....com>,
        Daniel Baluta <daniel.baluta@....com>,
        Andy Gross <andy.gross@...aro.org>,
        "horms+renesas@...ge.net.au" <horms+renesas@...ge.net.au>,
        "heiko@...ech.de" <heiko@...ech.de>,
        "arnd@...db.de" <arnd@...db.de>,
        "bjorn.andersson@...aro.org" <bjorn.andersson@...aro.org>,
        "jagan@...rulasolutions.com" <jagan@...rulasolutions.com>,
        "enric.balletbo@...labora.com" <enric.balletbo@...labora.com>,
        "marc.w.gonzalez@...e.fr" <marc.w.gonzalez@...e.fr>,
        "olof@...om.net" <olof@...om.net>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
        dl-linux-imx <linux-imx@....com>
Subject: Re: [PATCH 3/3] cpufreq: imx-sc: add i.mx system controller cpufreq
 support

On 13-02-19, 08:46, Anson Huang wrote:
> Hi, Viresh
> 
> Best Regards!
> Anson Huang
> 
> > -----Original Message-----
> > From: Viresh Kumar [mailto:viresh.kumar@...aro.org]
> > Sent: 2019年2月13日 15:09
> > To: Anson Huang <anson.huang@....com>
> > Cc: robh+dt@...nel.org; mark.rutland@....com; shawnguo@...nel.org;
> > s.hauer@...gutronix.de; kernel@...gutronix.de; festevam@...il.com;
> > catalin.marinas@....com; will.deacon@....com; rjw@...ysocki.net;
> > Aisheng Dong <aisheng.dong@....com>; Daniel Baluta
> > <daniel.baluta@....com>; Andy Gross <andy.gross@...aro.org>;
> > horms+renesas@...ge.net.au; heiko@...ech.de; arnd@...db.de;
> > bjorn.andersson@...aro.org; jagan@...rulasolutions.com;
> > enric.balletbo@...labora.com; marc.w.gonzalez@...e.fr; olof@...om.net;
> > devicetree@...r.kernel.org; linux-arm-kernel@...ts.infradead.org; linux-
> > kernel@...r.kernel.org; linux-pm@...r.kernel.org; dl-linux-imx <linux-
> > imx@....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@....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

Why do you need to implement arch_set_freq_scale() ? It is already
defined for arm64 I believe.

> 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.

Yes, it supports multi-cluster.

-- 
viresh