Re: [PATCH v1 1/3] drivers/platform: lenovo-t14s-ec: Add hwmon support for temperatures and fan speed

[Daniel Lezcano]

On 6/28/26 15:50, Sebastian Reichel wrote:
> Hi,
>
> On Wed, Jun 24, 2026 at 11:08:23PM +0200, Daniel Lezcano wrote:
> > Expose the Lenovo ThinkPad T14s EC environmental sensors through
> > the hwmon subsystem.
> >
> > The driver now registers a hwmon device providing access to six EC
> > temperature sensors corresponding to the SoC, keyboard area, base
> > cover, PMIC/charging circuitry, QTM module and SSD. Sensor labels
> > are exported to allow user space to identify each measurement.
> >
> > Additionally, expose the system fan speed by reading the fan RPM
> > registers from the embedded controller.
> >
> > This allows standard monitoring tools such as lm-sensors to report
> > platform temperatures and fan speed.
> >
> > Signed-off-by: Daniel Lezcano daniel.lezcano@xxxxxxxxxxxxxxxx
> > ---
>
> I gave this a try and for me the fan data is always 65535 (i.e. -1):
>
> $ cat /sys/class/hwmon/hwmon66/{name,fan1_input}
> t14s_ec
> 65535

Strange, I have:

fan speed=0, temp=40000
fan speed=0, temp=41000
fan speed=0, temp=41000
fan speed=0, temp=43000
fan speed=0, temp=43000
fan speed=0, temp=44000
fan speed=0, temp=44000
fan speed=0, temp=45000
fan speed=0, temp=46000
fan speed=0, temp=46000
fan speed=65535, temp=48000
          ^^^
fan speed=1903, temp=48000
fan speed=2345, temp=49000
fan speed=2367, temp=49000
fan speed=2417, temp=50000
fan speed=2431, temp=50000
fan speed=2430, temp=51000
fan speed=2441, temp=51000
fan speed=2450, temp=52000
fan speed=2457, temp=52000
fan speed=2458, temp=53000
fan speed=2458, temp=53000
fan speed=2458, temp=54000
fan speed=2460, temp=54000
fan speed=2572, temp=55000
fan speed=2788, temp=55000
fan speed=3009, temp=55000
fan speed=3229, temp=56000
fan speed=3424, temp=56000
fan speed=3610, temp=56000
fan speed=3631, temp=56000
fan speed=3597, temp=56000
fan speed=3594, temp=56000
fan speed=3592, temp=56000
fan speed=3592, temp=56000
fan speed=3588, temp=56000
fan speed=3588, temp=56000
fan speed=3594, temp=56000
fan speed=3594, temp=56000
fan speed=3597, temp=56000
fan speed=3597, temp=56000
fan speed=3594, temp=56000
fan speed=3597, temp=55000
fan speed=3594, temp=55000
fan speed=3594, temp=55000
fan speed=3592, temp=55000
fan speed=3592, temp=54000
fan speed=3588, temp=54000
fan speed=3592, temp=53000
fan speed=3590, temp=53000
fan speed=3592, temp=52000
fan speed=3590, temp=52000
fan speed=3588, temp=52000
fan speed=3588, temp=52000


> This is with the fan running:
>
> $ cat /sys/class/hwmon/hwmon57/{name,fan1_input}
> fan-controller
> 2564