[PATCHv5] extcon: Add resource-managed extcon register function
From: Chanwoo Choi
Date: Mon Apr 21 2014 - 06:36:53 EST
From: Sangjung Woo <sangjung.woo@xxxxxxxxxxx>
Add resource-managed extcon device register function for convenience.
For example, if a extcon device is attached with new
devm_extcon_dev_register(), that extcon device is automatically
unregistered on driver detach.
Signed-off-by: Sangjung Woo <sangjung.woo@xxxxxxxxxxx>
[Fix bug about devm_extcon_dev_match/release() and code clean by Chanwoo Choi]
Signed-off-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
---
drivers/extcon/extcon-class.c | 69 +++++++++++++++++++++++++++++++++++++++++++
include/linux/extcon.h | 17 +++++++++++
2 files changed, 86 insertions(+)
diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c
index 7ab21aa..f6df689 100644
--- a/drivers/extcon/extcon-class.c
+++ b/drivers/extcon/extcon-class.c
@@ -819,6 +819,75 @@ void extcon_dev_unregister(struct extcon_dev *edev)
}
EXPORT_SYMBOL_GPL(extcon_dev_unregister);
+static void devm_extcon_dev_unreg(struct device *dev, void *res)
+{
+ extcon_dev_unregister(*(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_register() - Resource-managed extcon_dev_register()
+ * @dev: device to allocate extcon device
+ * @edev: the new extcon device to register
+ *
+ * Managed extcon_dev_register() function. If extcon device is attached with
+ * this function, that extcon device is automatically unregistered on driver
+ * detach. Internally this function calls extcon_dev_register() function.
+ * To get more information, refer that function.
+ *
+ * If extcon device is registered with this function and the device needs to be
+ * unregistered separately, devm_extcon_dev_unregister() should be used.
+ *
+ * Returns 0 if success or negaive error number if failure.
+ */
+int devm_extcon_dev_register(struct device *dev, struct extcon_dev *edev)
+{
+ struct extcon_dev **ptr;
+ int ret;
+
+ ptr = devres_alloc(devm_extcon_dev_unreg, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return -ENOMEM;
+
+ ret = extcon_dev_register(edev);
+ if (ret) {
+ devres_free(ptr);
+ return ret;
+ }
+
+ *ptr = edev;
+ devres_add(dev, ptr);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(devm_extcon_dev_register);
+
+/**
+ * devm_extcon_dev_unregister() - Resource-managed extcon_dev_unregister()
+ * @dev: device the extcon belongs to
+ * @edev: the extcon device to unregister
+ *
+ * Unregister extcon device that is registered with devm_extcon_dev_register()
+ * function.
+ */
+void devm_extcon_dev_unregister(struct device *dev, struct extcon_dev *edev)
+{
+ WARN_ON(devres_release(dev, devm_extcon_dev_unreg,
+ devm_extcon_dev_match, edev));
+}
+EXPORT_SYMBOL_GPL(devm_extcon_dev_unregister);
+
#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 f488145..85a8a5b 100644
--- a/include/linux/extcon.h
+++ b/include/linux/extcon.h
@@ -188,6 +188,14 @@ extern void extcon_dev_unregister(struct extcon_dev *edev);
extern struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name);
/*
+ * Resource-managed extcon device register function.
+ */
+extern int devm_extcon_dev_register(struct device *dev,
+ struct extcon_dev *edev);
+extern void devm_extcon_dev_unregister(struct device *dev,
+ struct extcon_dev *edev);
+
+/*
* get/set/update_state access the 32b encoded state value, which represents
* states of all possible cables of the multistate port. For example, if one
* calls extcon_set_state(edev, 0x7), it may mean that all the three cables
@@ -254,6 +262,15 @@ static inline int extcon_dev_register(struct extcon_dev *edev)
static inline void extcon_dev_unregister(struct extcon_dev *edev) { }
+static inline int devm_extcon_dev_register(struct device *dev,
+ struct extcon_dev *edev)
+{
+ return -EINVAL;
+}
+
+static inline void devm_extcon_dev_unregister(struct device *dev,
+ struct extcon_dev *edev) { }
+
static inline u32 extcon_get_state(struct extcon_dev *edev)
{
return 0;
--
1.8.0
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