[PATCH v16 06/10] iio: imu: inv_icm42607: Add PM support for icm42607

[Andy Shevchenko]

On Mon, Jul 13, 2026 at 04:58:36PM -0500, Chris Morgan wrote:

> Add power management support for the ICM42607 device driver.

...

> +static int inv_icm42607_set_pwr_mgmt0(struct inv_icm42607_state *st,
> +				      enum inv_icm42607_sensor_mode gyro,
> +				      enum inv_icm42607_sensor_mode accel)
> +{
> +	unsigned int oldaccel, oldgyro;
> +	unsigned int sleepval_us;
> +	unsigned int val;
> +	s64 disable_wait;
> +	int ret;
> +
> +	ret = inv_icm42607_get_pwr_mgmt0(st, &oldgyro, &oldaccel);
> +	if (ret)
> +		return ret;
> +
> +	if (gyro == oldgyro && accel == oldaccel)
> +		return 0;
> +
> +	/*
> +	 * Datasheet on page 14.26 says we need to ensure the gyro sensor is on
> +	 * for a minimum of 45ms. So if we transition from an on state to an
> +	 * off state make sure at least 45ms have passed before power off and
> +	 * wait if it hasn't.
> +	 */
> +	if (!gyro && oldgyro) {
> +		disable_wait = ktime_us_delta(st->conf.gyro_stop, ktime_get());
> +		disable_wait = clamp(disable_wait,
> +				     0, INV_ICM42607_GYRO_STOP_TIME_US);

I would go with this slightly longer line

		disable_wait = clamp(ktime_us_delta(st->conf.gyro_stop, ktime_get()),
				     0, INV_ICM42607_GYRO_STOP_TIME_US);

> +		fsleep(disable_wait);
> +	}
> +
> +	val = FIELD_PREP(INV_ICM42607_PWR_MGMT0_GYRO_MODE_MASK, gyro) |
> +	      FIELD_PREP(INV_ICM42607_PWR_MGMT0_ACCEL_MODE_MASK, accel);
> +	ret = regmap_write(st->map, INV_ICM42607_REG_PWR_MGMT0, val);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * If a state change occurs from off to on, sleep for the startup
> +	 * time of the sensor, unless a sleep_ms is specified. Since more
> +	 * than one sensor can be transitioned from off to on, select the
> +	 * maximum time from each of the sensors changing from off to on.
> +	 * The startup time for the temp sensor is considerably smaller
> +	 * than the startup time for the other sensors and one or more are
> +	 * required to be on for the temp sensor to function, so any start
> +	 * delay should be enough.
> +	 */
> +	sleepval_us = 0;
> +	if (accel && !oldaccel)
> +		sleepval_us = max(sleepval_us, INV_ICM42607_ACCEL_STARTUP_TIME_US);
> +
> +	if (gyro && !oldgyro) {
> +		sleepval_us = max(sleepval_us, INV_ICM42607_GYRO_STARTUP_TIME_US);
> +		/* Track the earliest we can turn off the gyroscope. */
> +		st->conf.gyro_stop = ktime_add_us(ktime_get(),
> +						  INV_ICM42607_GYRO_STOP_TIME_US);
> +	}

> +	/* Only sleep if sleepval_us is greater than 0 in case some
> +	 * platforms have issues with a 0 delay. The 0 delay can happen
> +	 * if one or both sensors is shut down.
> +	 */

/*
 * Use the same style for mutli-line comment
 * in all comments.
 */

> +	if (sleepval_us > 0)
> +		fsleep(sleepval_us);
> +
> +	return 0;
> +}

...

> +EXPORT_NS_GPL_DEV_PM_OPS(inv_icm42607_pm_ops, IIO_ICM42607) = {
> +	SYSTEM_SLEEP_PM_OPS(inv_icm42607_suspend, inv_icm42607_resume)

> +	RUNTIME_PM_OPS(inv_icm42607_runtime_suspend,
> +		       inv_icm42607_runtime_resume,
> +		       NULL)

Hmm... perhaps just a single line as well?

	RUNTIME_PM_OPS(inv_icm42607_runtime_suspend, inv_icm42607_runtime_resume, NULL)

> +};

-- 
With Best Regards,
Andy Shevchenko