From: Kamil Debski <k.debski@samsung.com>
Date: Mon, 3 Nov 2014 14:42:55 +0000 (+0100)
Subject: hwmon: (pwm-fan) Fix suspend/resume behavior
X-Git-Tag: v3.18-rc5~35^2~1
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=48b9d5b4f408259cd6800c4b17d4fe5025435da2;p=platform%2Fkernel%2Flinux-exynos.git

hwmon: (pwm-fan) Fix suspend/resume behavior

The state of a PWM output is not clearly defined after resume. Some PWM
drivers do not restore the duty cycle upon resume, thus it is necessary to
manually restore the correct value.

Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---

diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index 823c877..1991d903 100644
--- a/drivers/hwmon/pwm-fan.c
+++ b/drivers/hwmon/pwm-fan.c
@@ -161,10 +161,17 @@ static int pwm_fan_suspend(struct device *dev)
 static int pwm_fan_resume(struct device *dev)
 {
 	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
+	unsigned long duty;
+	int ret;
 
-	if (ctx->pwm_value)
-		return pwm_enable(ctx->pwm);
-	return 0;
+	if (ctx->pwm_value == 0)
+		return 0;
+
+	duty = DIV_ROUND_UP(ctx->pwm_value * (ctx->pwm->period - 1), MAX_PWM);
+	ret = pwm_config(ctx->pwm, duty, ctx->pwm->period);
+	if (ret)
+		return ret;
+	return pwm_enable(ctx->pwm);
 }
 #endif