PM / devfreq: Add resource-managed function for devfreq device

This patch add resource-managed function for devfreq device as following
functions. The devm_devfreq_add_device() manages automatically the memory
of devfreq device using device resource management.
- devm_devfreq_add_device()
- devm_devfreq_remove_device()

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

2 files changed, 83 insertions, 1 deletions

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index af4af7708574..8b6295d9d1f5 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -544,6 +544,69 @@ int devfreq_remove_device(struct devfreq *devfreq)
 }
 EXPORT_SYMBOL(devfreq_remove_device);
 
+static int devm_devfreq_dev_match(struct device *dev, void *res, void *data)
+{
+        struct devfreq **r = res;
+
+        if (WARN_ON(!r || !*r))
+                return 0;
+
+        return *r == data;
+}
+
+static void devm_devfreq_dev_release(struct device *dev, void *res)
+{
+        devfreq_remove_device(*(struct devfreq **)res);
+}
+
+/**
+ * devm_devfreq_add_device() - Resource-managed devfreq_add_device()
+ * @dev:        the device to add devfreq feature.
+ * @profile:    device-specific profile to run devfreq.
+ * @governor_name:      name of the policy to choose frequency.
+ * @data:       private data for the governor. The devfreq framework does not
+ *              touch this value.
+ *
+ * This function manages automatically the memory of devfreq device using device
+ * resource management and simplify the free operation for memory of devfreq
+ * device.
+ */
+struct devfreq *devm_devfreq_add_device(struct device *dev,
+                                        struct devfreq_dev_profile *profile,
+                                        const char *governor_name,
+                                        void *data)
+{
+        struct devfreq **ptr, *devfreq;
+
+        ptr = devres_alloc(devm_devfreq_dev_release, sizeof(*ptr), GFP_KERNEL);
+        if (!ptr)
+                return ERR_PTR(-ENOMEM);
+
+        devfreq = devfreq_add_device(dev, profile, governor_name, data);
+        if (IS_ERR(devfreq)) {
+                devres_free(ptr);
+                return ERR_PTR(-ENOMEM);
+        }
+
+        *ptr = devfreq;
+        devres_add(dev, ptr);
+
+        return devfreq;
+}
+EXPORT_SYMBOL(devm_devfreq_add_device);
+
+/**
+ * devm_devfreq_remove_device() - Resource-managed devfreq_remove_device()
+ * @dev:        the device to add devfreq feature.
+ * @devfreq:    the devfreq instance to be removed
+ */
+void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq)
+{
+        WARN_ON(devres_release(dev, devm_devfreq_dev_release,
+                               devm_devfreq_dev_match, devfreq));
+}
+EXPORT_SYMBOL(devm_devfreq_remove_device);
+
 /**
  * devfreq_suspend_device() - Suspend devfreq of a device.
  * @devfreq: the devfreq instance to be suspended
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index d48dc00232a4..023d668a2cb5 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -181,6 +181,12 @@ extern struct devfreq *devfreq_add_device(struct device *dev,
                                   const char *governor_name,
                                   void *data);
 extern int devfreq_remove_device(struct devfreq *devfreq);
+extern struct devfreq *devm_devfreq_add_device(struct device *dev,
+                                  struct devfreq_dev_profile *profile,
+                                  const char *governor_name,
+                                  void *data);
+extern void devm_devfreq_remove_device(struct device *dev,
+                                  struct devfreq *devfreq);
 
 /* Supposed to be called by PM_SLEEP/PM_RUNTIME callbacks */
 extern int devfreq_suspend_device(struct devfreq *devfreq);
@@ -220,7 +226,7 @@ static inline struct devfreq *devfreq_add_device(struct device *dev,
                                           const char *governor_name,
                                           void *data)
 {
-        return NULL;
+        return ERR_PTR(-ENOSYS);
 }
 
 static inline int devfreq_remove_device(struct devfreq *devfreq)
@@ -228,6 +234,19 @@ static inline int devfreq_remove_device(struct devfreq *devfreq)
         return 0;
 }
 
+static inline struct devfreq *devm_devfreq_add_device(struct device *dev,
+                                        struct devfreq_dev_profile *profile,
+                                        const char *governor_name,
+                                        void *data)
+{
+        return ERR_PTR(-ENOSYS);
+}
+
+static inline void devm_devfreq_remove_device(struct device *dev,
+                                        struct devfreq *devfreq)
+{
+}
+
 static inline int devfreq_suspend_device(struct devfreq *devfreq)
 {
         return 0;