pwm: add devm_pwm_get() and devm_pwm_put()
Add resource managed variants of pwm_get() and pwm_put() for
convenience. Code is largely inspired by the equivalent devm functions
of the regulator framework.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index 950856b..43cff70 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -284,3 +284,7 @@
PINCTRL
devm_pinctrl_get()
devm_pinctrl_put()
+
+PWM
+ devm_pwm_get()
+ devm_pwm_put()
diff --git a/Documentation/pwm.txt b/Documentation/pwm.txt
index 554290e..7d2b4c9 100644
--- a/Documentation/pwm.txt
+++ b/Documentation/pwm.txt
@@ -36,7 +36,8 @@
after usage with pwm_free().
New users should use the pwm_get() function and pass to it the consumer
-device or a consumer name. pwm_put() is used to free the PWM device.
+device or a consumer name. pwm_put() is used to free the PWM device. Managed
+variants of these functions, devm_pwm_get() and devm_pwm_put(), also exist.
After being requested a PWM has to be configured using:
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 85592e9..92b1782 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -646,6 +646,64 @@
}
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)
{
diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index 354764c..40c7643 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -148,6 +148,9 @@
struct pwm_device *pwm_get(struct device *dev, const char *consumer);
void pwm_put(struct pwm_device *pwm);
+struct pwm_device *devm_pwm_get(struct device *dev, const char *consumer);
+void devm_pwm_put(struct device *dev, struct pwm_device *pwm);
+
struct pwm_lookup {
struct list_head list;
const char *provider;
