iio: common: scmi_sensors: Get rid of const_ilog2()

Fisrt of all, const_ilog2() was a workaround of some sparse issue,
which was never appeared in the C functions. Second, the calls here
are done against constants and work with a bit of luck. Replace
this altogether by a pre-calculated simple integer constant.
Amend a comment to give a hint where it comes from.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/common/scmi_sensors/scmi_iio.c b/drivers/iio/common/scmi_sensors/scmi_iio.c
index 39c61c47022a58b37168382f7645d7772636d6a9..5136ad9ada0409a9a76fc2ce0a415210734dc43c 100644 (file)
--- a/drivers/iio/common/scmi_sensors/scmi_iio.c
+++ b/drivers/iio/common/scmi_sensors/scmi_iio.c
@@ -66,10 +66,9 @@ static int scmi_iio_sensor_update_cb(struct notifier_block *nb,
                /*
                 *  Timestamp returned by SCMI is in seconds and is equal to
                 *  time * power-of-10 multiplier(tstamp_scale) seconds.
-                *  Converting the timestamp to nanoseconds below.
+                *  Converting the timestamp to nanoseconds (10⁹) below.
                 */
-               tstamp_scale = sensor->sensor_info->tstamp_scale +
-                              const_ilog2(NSEC_PER_SEC) / const_ilog2(10);
+               tstamp_scale = sensor->sensor_info->tstamp_scale + 9;
                if (tstamp_scale < 0) {
                        do_div(time, int_pow(10, abs(tstamp_scale)));
                        time_ns = time;