iio: adc: ad4134: Specify PWM parameters in nanoseconds

With ref_clk running with a rate not bigger than 1 GHz there is no gain
in using picosecond units as two different PWM settings differ by at
least one nanosecond. So there is no need to differ from upstream where
the pwm subsystem uses nanoseconds to specify PWM parameters.

With the goal to drop support for time_unit, don't explicitly set
state.time_unit = PWM_UNIT_NSEC but rely on this being the default.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>

Author: ukleinek

drivers/iio/adc/ad4134.c

@@ -95,9 +95,8 @@ static int _ad4134_set_odr(struct ad4134_state *st, unsigned int odr)
 	 * tODR_HIGH_TIME = 3 * tDIGCLK
 	 * See datasheet page 10, Table 3. Data Interface Timing with Gated DCLK.
 	 */
-	state.duty_cycle = DIV_ROUND_CLOSEST_ULL(PICO * 6, st->sys_clk_rate);
-	state.period = DIV_ROUND_CLOSEST_ULL(PICO, odr);
-	state.time_unit = PWM_UNIT_PSEC;
+	state.duty_cycle = DIV_ROUND_CLOSEST_ULL(6ULL * NSEC_PER_SEC, st->sys_clk_rate);
+	state.period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, odr);
 
 	ret = pwm_apply_state(st->odr_pwm, &state);
 	if (ret)