commit 8a08b966fe5838baec12754480948403fe07a48a
author Willie Ruan <wruan@codeaurora.org> Tue Jul 05 00:43:37 2011 -0700
committer Bryan Huntsman <bryanh@codeaurora.org> Mon Oct 03 16:14:26 2011 -0700
tree ff2244181b6cbc719d840407d941cab5c56ad402
parent efc2fa44f633dc5e3cb435c9737b988147150d6d

misc: pm8058-pwm: bypass period calculation if no change

If a period is the same as before, there is no need to recalculate
it. This patch is adding such optimizations.

Signed-off-by: Willie Ruan <wruan@codeaurora.org>

drivers/misc/pmic8058-pwm.c

diff --git a/drivers/misc/pmic8058-pwm.c b/drivers/misc/pmic8058-pwm.c
index ddf29c5..451bb56 100644
--- a/drivers/misc/pmic8058-pwm.c
+++ b/drivers/misc/pmic8058-pwm.c
@@ -625,7 +625,7 @@
 	int				rc;
 
 	if (pwm == NULL || IS_ERR(pwm) ||
-		(unsigned)duty_us > (unsigned)period_us ||
+		duty_us > period_us ||
 		(unsigned)period_us > PM_PWM_PERIOD_MAX ||
 		(unsigned)period_us < PM_PWM_PERIOD_MIN)
 		return -EINVAL;
@@ -639,9 +639,12 @@
 		goto out_unlock;
 	}
 
-	pm8058_pwm_calc_period(period_us, &pwm->period);
+	if (pwm->pwm_period != period_us) {
+		pm8058_pwm_calc_period(period_us, &pwm->period);
+		pm8058_pwm_save_period(pwm);
+		pwm->pwm_period = period_us;
+	}
 
-	pm8058_pwm_save_period(pwm);
 	pm8058_pwm_calc_pwm_value(pwm, period_us, duty_us);
 	pm8058_pwm_save_pwm_value(pwm);
 	pm8058_pwm_save(&pwm->pwm_ctl[1],
@@ -754,8 +757,11 @@
 		goto out_unlock;
 	}
 
-	pm8058_pwm_calc_period(period_us, &pwm->period);
-	pm8058_pwm_save_period(pwm);
+	if (pwm->pwm_period != period_us) {
+		pm8058_pwm_calc_period(period_us, &pwm->period);
+		pm8058_pwm_save_period(pwm);
+		pwm->pwm_period = period_us;
+	}
 
 	len = (idx_len > PM_PWM_LUT_SIZE) ? PM_PWM_LUT_SIZE : idx_len;