extcon: Add the synchronization extcon APIs to support the notification

This patch adds the synchronization extcon APIs to support the notifications
for both state and property. When extcon_*_sync() functions is called,
the extcon informs the information from extcon provider to extcon client.

The extcon driver may need to change the both state and multiple properties
at the same time. After setting the data of a external connector,
the extcon send the notification to client driver with the extcon_*_sync().

The list of new extcon APIs as following:
- extcon_sync() : Send the notification for each external connector to
		synchronize the information between extcon provider driver
		and extcon client driver.
- extcon_set_state_sync() : Set the state of external connector with noti.
- extcon_set_property_sync() : Set the property of external connector with noti.

For example,
case 1, change the state of external connector and synchronized the data.
	extcon_set_state_sync(edev, EXTCON_USB, 1);

case 2, change both the state and property of external connector
	and synchronized the data.
	extcon_set_state(edev, EXTCON_USB, 1);
	extcon_set_property(edev, EXTCON_USB, EXTCON_PROP_USB_VBUS 1);
	extcon_sync(edev, EXTCON_USB);

case 3, change the property of external connector and synchronized the data.
	extcon_set_property(edev, EXTCON_USB, EXTCON_PROP_USB_VBUS, 0);
	extcon_sync(edev, EXTCON_USB);

case 4, change the property of external connector and synchronized the data.
	extcon_set_property_sync(edev, EXTCON_USB, EXTCON_PROP_USB_VBUS, 0);

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Chris Zhong <zyw@rock-chips.com>
Tested-by: Guenter Roeck <groeck@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>

1 files changed, 29 insertions, 1 deletions

diff --git a/include/linux/extcon.h b/include/linux/extcon.h
index 4fa37385c97a..162c46a42bac 100644
--- a/include/linux/extcon.h
+++ b/include/linux/extcon.h
@@ -222,6 +222,13 @@ extern void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev);
 extern int extcon_get_state(struct extcon_dev *edev, unsigned int id);
 extern int extcon_set_state(struct extcon_dev *edev, unsigned int id,
 				   bool cable_state);
+extern int extcon_set_state_sync(struct extcon_dev *edev, unsigned int id,
+				bool cable_state);
+
+/*
+ * Synchronize the state and property data for a specific external connector.
+ */
+extern int extcon_sync(struct extcon_dev *edev, unsigned int id);
 
 /*
  * get/set_property access the property value of each external connector.
@@ -233,6 +240,9 @@ extern int extcon_get_property(struct extcon_dev *edev, unsigned int id,
 extern int extcon_set_property(struct extcon_dev *edev, unsigned int id,
 				unsigned int prop,
 				union extcon_property_value prop_val);
+extern int extcon_set_property_sync(struct extcon_dev *edev, unsigned int id,
+				unsigned int prop,
+				union extcon_property_value prop_val);
 
 /*
  * get/set_property_capability set the capability of the property for each
@@ -317,6 +327,17 @@ static inline int extcon_set_state(struct extcon_dev *edev, unsigned int id,
 	return 0;
 }
 
+static inline int extcon_set_state_sync(struct extcon_dev *edev, unsigned int id,
+				bool cable_state)
+{
+	return 0;
+}
+
+static inline int extcon_sync(struct extcon_dev *edev, unsigned int id)
+{
+	return 0;
+}
+
 static inline int extcon_get_property(struct extcon_dev *edev, unsigned int id,
 					unsigned int prop,
 					union extcon_property_value *prop_val)
@@ -330,6 +351,13 @@ static inline int extcon_set_property(struct extcon_dev *edev, unsigned int id,
 	return 0;
 }
 
+static inline int extcon_set_property_sync(struct extcon_dev *edev,
+					unsigned int id, unsigned int prop,
+					union extcon_property_value prop_val)
+{
+	return 0;
+}
+
 static inline int extcon_get_property_capability(struct extcon_dev *edev,
 					unsigned int id, unsigned int prop)
 {
@@ -411,6 +439,6 @@ static inline int extcon_get_cable_state_(struct extcon_dev *edev, unsigned int
 static inline int extcon_set_cable_state_(struct extcon_dev *edev, unsigned int id,
 				   bool cable_state)
 {
-	return extcon_set_state(edev, id, cable_state);
+	return extcon_set_state_sync(edev, id, cable_state);
 }
 #endif /* __LINUX_EXTCON_H__ */