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 823c877a1ec0952ce5fab7a465c79826f3442764..1991d9032c3843de2ffcd20b82f5790d22ce2684 100644 (file)
--- 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