linux-kernel - RE: [PATCH v2 10/14] cpufreq: dt: Allow platform specific intermediate callbacks

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Date:   Wed, 19 Feb 2020 09:41:53 +0000
From:   Peng Fan <peng.fan@....com>
To:     Viresh Kumar <viresh.kumar@...aro.org>
CC:     "shawnguo@...nel.org" <shawnguo@...nel.org>,
        "s.hauer@...gutronix.de" <s.hauer@...gutronix.de>,
        "sboyd@...nel.org" <sboyd@...nel.org>,
        "robh+dt@...nel.org" <robh+dt@...nel.org>,
        "rjw@...ysocki.net" <rjw@...ysocki.net>,
        "kernel@...gutronix.de" <kernel@...gutronix.de>,
        "festevam@...il.com" <festevam@...il.com>,
        dl-linux-imx <linux-imx@....com>,
        Anson Huang <anson.huang@....com>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Abel Vesa <abel.vesa@....com>
Subject: RE: [PATCH v2 10/14] cpufreq: dt: Allow platform specific
 intermediate callbacks

Hi Viresh,

> Subject: Re: [PATCH v2 10/14] cpufreq: dt: Allow platform specific
> intermediate callbacks
> 
> On 19-02-20, 15:59, peng.fan@....com wrote:
> > From: Peng Fan <peng.fan@....com>
> >
> > Platforms may need to implement platform specific get_intermediate and
> > target_intermediate hooks.
> >
> > Update cpufreq-dt driver's platform data to contain those for such
> > platforms.
> >
> > Signed-off-by: Peng Fan <peng.fan@....com>
> > ---
> >  drivers/cpufreq/cpufreq-dt.c | 4 ++++  drivers/cpufreq/cpufreq-dt.h |
> > 4 ++++
> >  2 files changed, 8 insertions(+)
> >
> > diff --git a/drivers/cpufreq/cpufreq-dt.c
> > b/drivers/cpufreq/cpufreq-dt.c index d2b5f062a07b..26fe8dfb9ce6 100644
> > --- a/drivers/cpufreq/cpufreq-dt.c
> > +++ b/drivers/cpufreq/cpufreq-dt.c
> > @@ -363,6 +363,10 @@ static int dt_cpufreq_probe(struct platform_device
> *pdev)
> >  		dt_cpufreq_driver.resume = data->resume;
> >  		if (data->suspend)
> >  			dt_cpufreq_driver.suspend = data->suspend;
> > +		if (data->get_intermediate) {
> > +			dt_cpufreq_driver.target_intermediate =
> data->target_intermediate;
> > +			dt_cpufreq_driver.get_intermediate = data->get_intermediate;
> > +		}
> >  	}
> >
> >  	ret = cpufreq_register_driver(&dt_cpufreq_driver);
> > diff --git a/drivers/cpufreq/cpufreq-dt.h
> > b/drivers/cpufreq/cpufreq-dt.h index a5a45b547d0b..28c8af7ec5ef 100644
> > --- a/drivers/cpufreq/cpufreq-dt.h
> > +++ b/drivers/cpufreq/cpufreq-dt.h
> > @@ -14,6 +14,10 @@ struct cpufreq_policy;  struct
> > cpufreq_dt_platform_data {
> >  	bool have_governor_per_policy;
> >
> > +	unsigned int	(*get_intermediate)(struct cpufreq_policy *policy,
> > +					    unsigned int index);
> > +	int		(*target_intermediate)(struct cpufreq_policy *policy,
> > +					       unsigned int index);
> 
> Who calls them ?

In drivers/cpufreq/cpufreq.c, function __target_index. Line 2065, see below:

2062         notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
2063         if (notify) {
2064                 /* Handle switching to intermediate frequency */
2065                 if (cpufreq_driver->get_intermediate) {
2066                         retval = __target_intermediate(policy, &freqs, index);
2067                         if (retval)
2068                                 return retval;
2069
2070                         intermediate_freq = freqs.new;
2071                         /* Set old freq to intermediate */
2072                         if (intermediate_freq)
2073                                 freqs.old = freqs.new;
2074                 }

Inspired from tegra20-cpufreq.c, use target_intermediate could handle
i.MX7ULP cpufreq easier.

Thanks,
Peng. 

> 
> --
> viresh