Re: [PATCH 1/3] hwmon: (cros_ec) Add setting target fan RPM function

From: Sung-Chi, Li
Date: Sun Mar 16 2025 - 23:55:37 EST


On Thu, Mar 13, 2025 at 05:21:35PM +0100, Thomas Weißschuh wrote:
> On 2025-03-13 12:47:42+0800, Sung-Chi Li wrote:
> > Implement the functionality of setting the target fan RPM to ChromeOS
> > embedded controller under hwmon framework.
> >
> > Signed-off-by: Sung-Chi Li <lschyi@xxxxxxxxxxxx>
> > ---
> > drivers/hwmon/cros_ec_hwmon.c | 34 ++++++++++++++++++++++++++++++++++
> > 1 file changed, 34 insertions(+)
> >
> > diff --git a/drivers/hwmon/cros_ec_hwmon.c b/drivers/hwmon/cros_ec_hwmon.c
> > index 9991c3fa020ac859cbbff29dfb669e53248df885..b2fec0768301f116f49c57b8dbfb042b98a573e1 100644
> > --- a/drivers/hwmon/cros_ec_hwmon.c
> > +++ b/drivers/hwmon/cros_ec_hwmon.c
> > @@ -52,6 +52,26 @@ static int cros_ec_hwmon_read_temp(struct cros_ec_device *cros_ec, u8 index, u8
> > return 0;
> > }
> >
> > +static int cros_ec_hwmon_set_fan_rpm(struct cros_ec_device *cros_ec, u8 index, u16 val)
> > +{
> > + struct ec_params_pwm_set_fan_target_rpm_v1 p_v1 = {
>
> The v1 protocol was "only" introduces in 2014.
> Could it be possible that devices without that command are still in use?
> If so the presence of the command should be probed.
>
You are right, I will probe the command versions for both get and set fan RPM
values in the next change, and perform different handling based on the version.