pwm: omap-dmtimer: Add debug message for effective period and duty cycle

After going through the math and constraints checking to compute load
and match values, it is helpful to know what the resultant period and
duty cycle are.

Signed-off-by: David Rivshin <[e-mail]>
Acked-by: Neil Armstrong <[e-mail]>
Signed-off-by: Thierry Reding <[e-mail]>

drivers/pwm/pwm-omap-dmtimer.c

···
 	unsigned long clk_rate;
 	bool timer_active;
 
-	dev_dbg(chip->dev, "duty cycle: %d, period %d\n", duty_ns, period_ns);
+	dev_dbg(chip->dev, "requested duty cycle: %d ns, period: %d ns\n",
+		duty_ns, period_ns);
 
 	mutex_lock(&omap->mutex);
 	if (duty_ns == pwm_get_duty_cycle(pwm) &&
···
 		dev_dbg(chip->dev, "using maximum of 1 clock cycle less than period\n");
 		duty_cycles = period_cycles - 1;
 	}
+
+	dev_dbg(chip->dev, "effective duty cycle: %lld ns, period: %lld ns\n",
+		DIV_ROUND_CLOSEST_ULL((u64)NSEC_PER_SEC * duty_cycles,
+				      clk_rate),
+		DIV_ROUND_CLOSEST_ULL((u64)NSEC_PER_SEC * period_cycles,
+				      clk_rate));
 
 	load_value = (DM_TIMER_MAX - period_cycles) + 1;
 	match_value = load_value + duty_cycles - 1;