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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>
This commit is contained in:
Kamil Debski 2014-11-03 15:42:55 +01:00 committed by Guenter Roeck
parent aab18da44f
commit 48b9d5b4f4
1 changed files with 10 additions and 3 deletions
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13
drivers/hwmon/pwm-fan.c
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@ -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