diff options
| author |   Kamil Debski <k.debski@samsung.com> | 2014-11-03 15:42:55 +0100 |
|---|---|---|
| committer |   Guenter Roeck <linux@roeck-us.net> | 2014-11-11 10:39:45 -0800 |
| commit | 48b9d5b4f408259cd6800c4b17d4fe5025435da2 (patch) | |
| tree | 9e6acd855c6088dd9d9dbbb2d95ccc665da4edda /drivers/hwmon/pwm-fan.c | |
| parent | hwmon: (ibmpowernv) Quieten when probing finds no device (diff) | |
| download | linux-dev-48b9d5b4f408259cd6800c4b17d4fe5025435da2.tar.xz linux-dev-48b9d5b4f408259cd6800c4b17d4fe5025435da2.zip | |
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>
Diffstat (limited to 'drivers/hwmon/pwm-fan.c')
| -rw-r--r-- | drivers/hwmon/pwm-fan.c | 13 |
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 |