1 files changed, 81 insertions, 1 deletions

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index c6e05078d3ad..f5acdaa52707 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -371,7 +371,7 @@ EXPORT_SYMBOL_GPL(pwm_free);
  */
 int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
 {
-        if (!pwm || period_ns == 0 || duty_ns > period_ns)
+        if (!pwm || duty_ns < 0 || period_ns <= 0 || duty_ns > period_ns)
                 return -EINVAL;
 
         return pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns);
@@ -379,6 +379,28 @@ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
 EXPORT_SYMBOL_GPL(pwm_config);
 
 /**
+ * pwm_set_polarity() - configure the polarity of a PWM signal
+ * @pwm: PWM device
+ * @polarity: new polarity of the PWM signal
+ *
+ * Note that the polarity cannot be configured while the PWM device is enabled
+ */
+int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
+{
+        if (!pwm || !pwm->chip->ops)
+                return -EINVAL;
+
+        if (!pwm->chip->ops->set_polarity)
+                return -ENOSYS;
+
+        if (test_bit(PWMF_ENABLED, &pwm->flags))
+                return -EBUSY;
+
+        return pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity);
+}
+EXPORT_SYMBOL_GPL(pwm_set_polarity);
+
+/**
  * pwm_enable() - start a PWM output toggling
  * @pwm: PWM device
  */
@@ -624,6 +646,64 @@ out:
 }
 EXPORT_SYMBOL_GPL(pwm_put);
 
+static void devm_pwm_release(struct device *dev, void *res)
+{
+        pwm_put(*(struct pwm_device **)res);
+}
+
+/**
+ * devm_pwm_get() - resource managed pwm_get()
+ * @dev: device for PWM consumer
+ * @con_id: consumer name
+ *
+ * This function performs like pwm_get() but the acquired PWM device will
+ * automatically be released on driver detach.
+ */
+struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
+{
+        struct pwm_device **ptr, *pwm;
+
+        ptr = devres_alloc(devm_pwm_release, sizeof(**ptr), GFP_KERNEL);
+        if (!ptr)
+                return ERR_PTR(-ENOMEM);
+
+        pwm = pwm_get(dev, con_id);
+        if (!IS_ERR(pwm)) {
+                *ptr = pwm;
+                devres_add(dev, ptr);
+        } else {
+                devres_free(ptr);
+        }
+
+        return pwm;
+}
+EXPORT_SYMBOL_GPL(devm_pwm_get);
+
+static int devm_pwm_match(struct device *dev, void *res, void *data)
+{
+        struct pwm_device **p = res;
+
+        if (WARN_ON(!p || !*p))
+                return 0;
+
+        return *p == data;
+}
+
+/**
+ * devm_pwm_put() - resource managed pwm_put()
+ * @dev: device for PWM consumer
+ * @pwm: PWM device
+ *
+ * Release a PWM previously allocated using devm_pwm_get(). Calling this
+ * function is usually not needed because devm-allocated resources are
+ * automatically released on driver detach.
+ */
+void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
+{
+        WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm));
+}
+EXPORT_SYMBOL_GPL(devm_pwm_put);
+
 #ifdef CONFIG_DEBUG_FS
 static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
 {