Re: [PATCH] iio: imu: inv_icm42600: fix temperature reading if accel/gyro is off

[Jonathan Cameron <jic23@kernel.org>]

On Tue, 08 Jul 2025 14:09:17 +0200
Sean Nyekjaer <sean@geanix.com> wrote:

> Avoid return invalid argument if one tries to read the temperature,.
> if both the accelerometer and gyro are off. Power the accelerometer on
> before reading the temperature.
> The original state will be restored by runtine_suspend() or the next
> reading of the accelerometer.
I'm not sure we are going ahead with this anyway given the other thread,
but if we did, then relying on runtime_put() in read of a different
channel seems like a bad design. If we think someone is interested
in reading the temperature of this sensor, are they guaranteed to
also be reading the acceleration?

> 
> Signed-off-by: Sean Nyekjaer <sean@geanix.com>
> ---
>  drivers/iio/imu/inv_icm42600/inv_icm42600_core.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c
> index a4d42e7e21807f7954def431e9cf03dffaa5bd5e..f97376bc8bb3dd225236e3f5036fd58af4af35ac 100644
> --- a/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c
> +++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c
> @@ -399,9 +399,14 @@ int inv_icm42600_set_gyro_conf(struct inv_icm42600_state *st,
>  int inv_icm42600_set_temp_conf(struct inv_icm42600_state *st, bool enable,
>  			       unsigned int *sleep_ms)
>  {
> -	return inv_icm42600_set_pwr_mgmt0(st, st->conf.gyro.mode,
> -					  st->conf.accel.mode, enable,
> -					  sleep_ms);
> +	enum inv_icm42600_sensor_mode accel = st->conf.accel.mode;
> +
> +	if (st->conf.gyro.mode == INV_ICM42600_SENSOR_MODE_OFF &&
> +	    st->conf.accel.mode == INV_ICM42600_SENSOR_MODE_OFF)
> +		accel = INV_ICM42600_SENSOR_MODE_LOW_POWER;
> +
> +	return inv_icm42600_set_pwr_mgmt0(st, st->conf.gyro.mode, accel,
> +					  enable, sleep_ms);
>  }
>  
>  int inv_icm42600_enable_wom(struct inv_icm42600_state *st)
> 
> ---
> base-commit: 3e28fa06444e7031aba0b3552cce332b776fe267
> change-id: 20250708-icm42temp-6292abddb6e6
> 
> Best regards,