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>

1 files changed, 10 insertions, 3 deletions

diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index 823c877a1ec0..1991d9032c38 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