linux-kernel - Re: [PATCH v6 1/7] thermal: sun8i: add thermal driver for H6/H5/H3/A64/A83T/R40

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Message-ID: <20191129005359.lyxtk5p7ebcon5uq@core.my.home>
Date:   Fri, 29 Nov 2019 01:53:59 +0100
From:   Ondřej Jirman <megous@...ous.com>
To:     Frank Lee <tiny.windzz@...il.com>
Cc:     Vasily Khoruzhick <anarsoul@...il.com>,
        Mark Rutland <mark.rutland@....com>,
        devicetree <devicetree@...r.kernel.org>,
        Amit Kucheria <amit.kucheria@...durent.com>,
        Linux PM <linux-pm@...r.kernel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Maxime Ripard <mripard@...nel.org>,
        Eduardo Valentin <edubezval@...il.com>,
        Chen-Yu Tsai <wens@...e.org>, Rob Herring <robh+dt@...nel.org>,
        Mauro Carvalho Chehab <mchehab+samsung@...nel.org>,
        Zhang Rui <rui.zhang@...el.com>,
        "David S. Miller" <davem@...emloft.net>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v6 1/7] thermal: sun8i: add thermal driver for
 H6/H5/H3/A64/A83T/R40

On Thu, Nov 28, 2019 at 11:16:05PM +0800, Frank Lee wrote:
> On Thu, Nov 28, 2019 at 6:24 AM Ondřej Jirman <megous@...ous.com> wrote:
> >
> > On Wed, Nov 27, 2019 at 11:48:32AM -0800, Vasily Khoruzhick wrote:
> > > On Wed, Nov 27, 2019 at 11:44 AM Frank Lee <tiny.windzz@...il.com> wrote:
> > > >
> > > > Hello Vasily,
> > > >
> > > > Thank you very much for your work on this.
> > > > This looks good to me.
> > >
> > > Thanks!
> > >
> > > > By the way, I would like to ask comments about adding the following code.
> > >
> > > Can we add it as follow up patch? I don't think that I have a device
> > > with working suspend to test it and I'm hesitant to add any code that
> > > I can't test.
> >
> > I have, but it doesn't use any of the clocks and resets, so it wouldn't
> > test this fully, and basicaly doesn't need re-calibration at all, probably.
> >
> > So that may be one feedback. On a83t, I'd made these callbacks a no-op.
> 
> This is just that the mainline code does not yet have the S2RAM code
> implementation of these SOCs.
> Each module has its own suspend function and resume function as part
> of the system suspend function.
> When the system is in S2RAM, the entire SOC will be completely powered
> off, and each module
> needs to save and restore its own state.

I know, but on A83T THS (named R_TH in the datasheet) is in the RTC power
domain, so it will not be powered down, even if you power down rest of the SoC.

I guess you can make it not run by other means, but it will not need restoring
any state, since it will not lose any during suspend.

regards,
	o.

> Yangtao
> 
> >
> > regards,
> >         o.
> >
> > > >
> > > > diff --git a/drivers/thermal/sun8i_thermal.c b/drivers/thermal/sun8i_thermal.c
> > > > index c0ed60782b11..579dde5e0701 100644
> > > > --- a/drivers/thermal/sun8i_thermal.c
> > > > +++ b/drivers/thermal/sun8i_thermal.c
> > > > @@ -629,11 +629,63 @@ static const struct of_device_id of_ths_match[] = {
> > > >  };
> > > >  MODULE_DEVICE_TABLE(of, of_ths_match);
> > > >
> > > > +static int __maybe_unused sun8i_thermal_suspend(struct device *dev)
> > > > +{
> > > > + struct ths_device *tmdev; = dev_get_drvdata(dev);
> > > > +
> > > > + clk_disable(tmdev->mod_clk);
> > > > + clk_disable(tmdev->bus_clk);
> > > > +
> > > > + reset_control_assert(tmdev->reset);
> > > > +
> > > > + return 0;
> > > > +}
> > > > +
> > > > +static int __maybe_unused sun8i_thermal_resume(struct device *dev)
> > > > +{
> > > > + struct ths_device *tmdev; = dev_get_drvdata(dev);
> > > > + int error;
> > > > +
> > > > + error = reset_control_deassert(tmdev->reset);
> > > > + if (error)
> > > > + return error;
> > > > +
> > > > + error = clk_enable(tmdev->bus_clk);
> > > > + if (error)
> > > > + goto assert_reset;
> > > > +
> > > > + clk_set_rate(tmdev->mod_clk, 24000000);
> > > > + error = clk_enable(tmdev->mod_clk);
> > > > + if (error)
> > > > + goto bus_disable;
> > > > +
> > > > + sun8i_ths_calibrate(tmdev);
> > > > +
> > > > + ret = tmdev->chip->init(tmdev);
> > > > + if (ret)
> > > > + goto mod_disable;
> > > > +
> > > > + return 0;
> > > > +
> > > > +mod_disable:
> > > > + clk_disable(tmdev->mod_clk);
> > > > +bus_disable:
> > > > + clk_disable(tmdev->bus_clk);
> > > > +assert_reset:
> > > > + reset_control_assert(tmdev->reset);
> > > > +
> > > > + return 0;
> > > > +}
> > > > +
> > > > +static SIMPLE_DEV_PM_OPS(sun8i_thermal_pm_ops,
> > > > + sun8i_thermal_suspend, sun8i_thermal_resume);
> > > > +
> > > >  static struct platform_driver ths_driver = {
> > > >   .probe = sun8i_ths_probe,
> > > >   .remove = sun8i_ths_remove,
> > > >   .driver = {
> > > >   .name = "sun8i-thermal",
> > > > + .pm = &sun8i_thermal_pm_ops,
> > > >   .of_match_table = of_ths_match,
> > > >   },
> > > >  };
> > > >
> > > > Yangtao
> > >
> > > _______________________________________________
> > > linux-arm-kernel mailing list
> > > linux-arm-kernel@...ts.infradead.org
> > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

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