Merge branches 'for-4.4/upstream-fixes', 'for-4.5/async-suspend', 'for-4.5/container...

[cascardo/linux.git] / drivers / pwm / core.c

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 3f9df3e..d24ca5f 100644 (file)
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -269,6 +269,7 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip,
                pwm->pwm = chip->base + i;
                pwm->hwpwm = i;
                pwm->polarity = polarity;
+               mutex_init(&pwm->lock);
 
                radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
        }
@@ -473,16 +474,22 @@ int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
        if (!pwm->chip->ops->set_polarity)
                return -ENOSYS;
 
-       if (pwm_is_enabled(pwm))
-               return -EBUSY;
+       mutex_lock(&pwm->lock);
+
+       if (pwm_is_enabled(pwm)) {
+               err = -EBUSY;
+               goto unlock;
+       }
 
        err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity);
        if (err)
-               return err;
+               goto unlock;
 
        pwm->polarity = polarity;
 
-       return 0;
+unlock:
+       mutex_unlock(&pwm->lock);
+       return err;
 }
 EXPORT_SYMBOL_GPL(pwm_set_polarity);
 
@@ -494,10 +501,22 @@ EXPORT_SYMBOL_GPL(pwm_set_polarity);
  */
 int pwm_enable(struct pwm_device *pwm)
 {
-       if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags))
-               return pwm->chip->ops->enable(pwm->chip, pwm);
+       int err = 0;
 
-       return pwm ? 0 : -EINVAL;
+       if (!pwm)
+               return -EINVAL;
+
+       mutex_lock(&pwm->lock);
+
+       if (!test_and_set_bit(PWMF_ENABLED, &pwm->flags)) {
+               err = pwm->chip->ops->enable(pwm->chip, pwm);
+               if (err)
+                       clear_bit(PWMF_ENABLED, &pwm->flags);
+       }
+
+       mutex_unlock(&pwm->lock);
+
+       return err;
 }
 EXPORT_SYMBOL_GPL(pwm_enable);
 
@@ -719,8 +738,10 @@ struct pwm_device *pwm_get(struct device *dev, const char *con_id)
                }
        }
 
-       if (!chosen)
+       if (!chosen) {
+               pwm = ERR_PTR(-ENODEV);
                goto out;
+       }
 
        chip = pwmchip_find_by_name(chosen->provider);
        if (!chip)