According to the Documentation/pwm.txt, all PWM consumers should have power management. Since this sysfs interface is one of consumers so that this patch adds suspend/resume support.
Signed-off-by: Yoshihiro Shimoda <[email protected]> --- drivers/pwm/sysfs.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c index 7eb4a13..72dafdd 100644 --- a/drivers/pwm/sysfs.c +++ b/drivers/pwm/sysfs.c @@ -18,6 +18,7 @@ struct pwm_export { struct device child; struct pwm_device *pwm; struct mutex lock; + bool enabled_in_suspend; }; static struct pwm_export *child_to_pwm_export(struct device *child) @@ -372,10 +373,73 @@ static struct attribute *pwm_chip_attrs[] = { }; ATTRIBUTE_GROUPS(pwm_chip); +static int pwm_class_suspend_resume(struct device *parent, bool suspend) +{ + struct pwm_chip *chip = dev_get_drvdata(parent); + unsigned int i; + int ret = 0; + + for (i = 0; i < chip->npwm; i++) { + struct pwm_device *pwm = &chip->pwms[i]; + struct device *child; + struct pwm_export *export; + struct pwm_state state; + + if (!test_bit(PWMF_EXPORTED, &pwm->flags)) + continue; + + child = device_find_child(parent, pwm, pwm_unexport_match); + if (!child) + goto rollback; + + export = child_to_pwm_export(child); + put_device(child); /* for device_find_child() */ + if (!export) + goto rollback; + + mutex_lock(&export->lock); + pwm_get_state(pwm, &state); + if (suspend) { + if (state.enabled) + export->enabled_in_suspend = true; + state.enabled = false; + } else if (export->enabled_in_suspend) { + state.enabled = true; + export->enabled_in_suspend = false; + } + ret = pwm_apply_state(pwm, &state); + mutex_unlock(&export->lock); + if (ret < 0) + goto rollback; + } + + return ret; + +rollback: + /* roll back only when suspend */ + if (suspend) + pwm_class_suspend_resume(parent, false); + + return ret; +} + +static int pwm_class_suspend(struct device *parent) +{ + return pwm_class_suspend_resume(parent, true); +} + +static int pwm_class_resume(struct device *parent) +{ + return pwm_class_suspend_resume(parent, false); +} + +static SIMPLE_DEV_PM_OPS(pwm_class_pm_ops, pwm_class_suspend, pwm_class_resume); + static struct class pwm_class = { .name = "pwm", .owner = THIS_MODULE, .dev_groups = pwm_chip_groups, + .pm = &pwm_class_pm_ops, }; static int pwmchip_sysfs_match(struct device *parent, const void *data) -- 2.7.4
