[PATCH 2/9] extcon: Add devm_extcon_dev_allocate/free to manage the resource of extcon device

[Chanwoo Choi]

This patch add device managed devm_extcon_dev_{allocate,free} to automatically
free the memory of extcon_dev structure without handling free operation.

Signed-off-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
---
 drivers/extcon/extcon-class.c | 57 +++++++++++++++++++++++++++++++++++++++++++
 include/linux/extcon.h        | 16 ++++++++++++
 2 files changed, 73 insertions(+)

diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c
index 600043c..b130446 100644
--- a/drivers/extcon/extcon-class.c
+++ b/drivers/extcon/extcon-class.c
@@ -848,6 +848,63 @@ void extcon_dev_free(struct extcon_dev *edev)
 }
 EXPORT_SYMBOL_GPL(extcon_dev_free);
 
+static void devm_extcon_device_release(struct device *dev, void *res)
+{
+	extcon_dev_free(*(struct extcon_dev **)res);
+}
+
+static int devm_extcon_dev_match(struct device *dev, void *res, void *data)
+{
+	struct extcon_dev **r = res;
+	if (!r || !*r) {
+		WARN_ON(!r || !*r);
+		return 0;
+	}
+	return *r == data;
+}
+
+/**
+ * devm_extcon_dev_allocate - Allocate managed extcon device
+ * @dev:		device owning the extcon device being created
+ * @supported_cable:	Array of supported cable names ending with NULL.
+ *			If supported_cable is NULL, cable name related APIs
+ *			are disabled.
+ *
+ * This function manages automatically the memory of extcon device using device
+ * resource management and simplify the control of freeing the memory of extcon
+ * device.
+ *
+ * Returns the pointer memory of allocated extcon_dev if success or NULL if fail
+ */
+struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
+					    const char **supported_cable)
+{
+	struct extcon_dev **res, *edev;
+
+	res = devres_alloc(devm_extcon_device_release, sizeof(*res),
+			   GFP_KERNEL);
+	if (!res)
+		return NULL;
+
+	edev = extcon_dev_allocate(supported_cable);
+	if (!IS_ERR(edev)) {
+		*res = edev;
+		devres_add(dev, res);
+	} else {
+		devres_free(res);
+	}
+
+	return edev;
+}
+EXPORT_SYMBOL_GPL(devm_extcon_dev_allocate);
+
+void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev)
+{
+	WARN_ON(devres_release(dev, devm_extcon_device_release,
+			       devm_extcon_dev_match, edev));
+}
+EXPORT_SYMBOL_GPL(devm_extcon_dev_free);
+
 #ifdef CONFIG_OF
 /*
  * extcon_get_edev_by_phandle - Get the extcon device from devicetree
diff --git a/include/linux/extcon.h b/include/linux/extcon.h
index ffb3a03..12ab2a8 100644
--- a/include/linux/extcon.h
+++ b/include/linux/extcon.h
@@ -246,6 +246,8 @@ extern int extcon_unregister_notifier(struct extcon_dev *edev,
 /*
  * Following APIs control the memory of extcon device.
  */
+extern struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
+						   const char **cables);
 extern struct extcon_dev *extcon_dev_allocate(const char **cables);
 extern void extcon_dev_free(struct extcon_dev *edev);
 
@@ -345,11 +347,25 @@ static inline struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev,
 	return ERR_PTR(-ENODEV);
 }
 
+static inline struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
+							  const char **cables)
+{
+	return -ENOMEM;
+}
+
 static inline struct extcon_dev *extcon_dev_allocate(const char **cables)
 {
 	return ERR_PTR(-ENOMEM);
 }
 
 static inline void extcon_dev_free(struct extcon_dev *edev) { }
+
+static inline struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
+							  const char **cables)
+{
+	return ERR_PTR(-ENOMEM);
+}
+
+static inline void devm_extcon_dev_free(struct extcon_dev *edev) { }
 #endif /* CONFIG_EXTCON */
 #endif /* __LINUX_EXTCON_H__ */
-- 
1.8.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/