linux-kernel - Re: [PATCH v2 6/6] platform/x86: ayaneo-ec: Add suspend hook

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Message-ID: 
 <CAGwozwHsMErRA+eDSCH+3XU6Q4Up7qTSqJ5y29-SdP0aMErUTg@mail.gmail.com>
Date: Wed, 15 Oct 2025 11:16:53 +0200
From: Antheas Kapenekakis <lkml@...heas.dev>
To: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
Cc: platform-driver-x86@...r.kernel.org, LKML <linux-kernel@...r.kernel.org>,
	linux-hwmon@...r.kernel.org, Hans de Goede <hansg@...nel.org>,
	Derek John Clark <derekjohn.clark@...il.com>,
	Joaquín Ignacio Aramendía <samsagax@...il.com>,
	Jean Delvare <jdelvare@...e.com>, Guenter Roeck <linux@...ck-us.net>
Subject: Re: [PATCH v2 6/6] platform/x86: ayaneo-ec: Add suspend hook

On Wed, 15 Oct 2025 at 11:11, Ilpo Järvinen
<ilpo.jarvinen@...ux.intel.com> wrote:
>
> On Wed, 15 Oct 2025, Antheas Kapenekakis wrote:
>
> > The Ayaneo EC resets after hibernation, losing the charge control state.
> > Add a small PM hook to restore this state on hibernation resume.
> >
> > The fan speed is also lost during hibernation, but since hibernation
> > failures are common with this class of devices, setting a low fan speed
> > when the userspace program controlling the fan will potentially not
> > take over could cause the device to overheat, so it is not restored.
> >
> > Signed-off-by: Antheas Kapenekakis <lkml@...heas.dev>
> > ---
> >  drivers/platform/x86/ayaneo-ec.c | 42 ++++++++++++++++++++++++++++++++
> >  1 file changed, 42 insertions(+)
> >
> > diff --git a/drivers/platform/x86/ayaneo-ec.c b/drivers/platform/x86/ayaneo-ec.c
> > index 73e9dd39c703..8529f6f8dc69 100644
> > --- a/drivers/platform/x86/ayaneo-ec.c
> > +++ b/drivers/platform/x86/ayaneo-ec.c
> > @@ -37,6 +37,8 @@
> >  #define AYANEO_MODULE_LEFT   BIT(0)
> >  #define AYANEO_MODULE_RIGHT  BIT(1)
> >
> > +#define AYANEO_CACHE_LEN     1
> > +
> >  struct ayaneo_ec_quirk {
> >       bool has_fan_control;
> >       bool has_charge_control;
> > @@ -47,6 +49,8 @@ struct ayaneo_ec_platform_data {
> >       struct platform_device *pdev;
> >       struct ayaneo_ec_quirk *quirks;
> >       struct acpi_battery_hook battery_hook;
> > +
> > +     u8 cache[AYANEO_CACHE_LEN];
> >  };
> >
> >  static const struct ayaneo_ec_quirk quirk_fan = {
> > @@ -464,10 +468,48 @@ static int ayaneo_ec_probe(struct platform_device *pdev)
> >       return 0;
> >  }
> >
> > +static int ayaneo_freeze(struct device *dev)
> > +{
> > +     struct platform_device *pdev = to_platform_device(dev);
> > +     struct ayaneo_ec_platform_data *data = platform_get_drvdata(pdev);
> > +     int ret, i = 0;
> > +
> > +     if (data->quirks->has_charge_control) {
> > +             ret = ec_read(AYANEO_CHARGE_REG, &data->cache[i]);
> > +             if (ret)
> > +                     return ret;
> > +             i++;
>
> What is this for?

Adding additional registers to restore. Currently, there is only one
so it looks out of place.

> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static int ayaneo_thaw(struct device *dev)
> > +{
> > +     struct platform_device *pdev = to_platform_device(dev);
> > +     struct ayaneo_ec_platform_data *data = platform_get_drvdata(pdev);
> > +     int ret, i = 0;
> > +
> > +     if (data->quirks->has_charge_control) {
> > +             ret = ec_write(AYANEO_CHARGE_REG, data->cache[i]);
> > +             if (ret)
> > +                     return ret;
> > +             i++;
>
> Same question here.
>
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct dev_pm_ops ayaneo_pm_ops = {
> > +     .freeze = ayaneo_freeze,
> > +     .thaw = ayaneo_thaw,
> > +};
> > +
> >  static struct platform_driver ayaneo_platform_driver = {
> >       .driver = {
> >               .name = "ayaneo-ec",
> >               .dev_groups = ayaneo_ec_groups,
> > +             .pm = &ayaneo_pm_ops,
> >       },
> >       .probe = ayaneo_ec_probe,
> >  };
> >
>
> --
>  i.
>
>