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path: root/drivers/pwm/core.c
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Diffstat (limited to 'drivers/pwm/core.c')
-rw-r--r--drivers/pwm/core.c82
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)
{