From 74c5d09bd562edc220d6e076b8f1e118819c178f Mon Sep 17 00:00:00 2001 From: Donggeun Kim Date: Fri, 20 Apr 2012 14:16:24 +0900 Subject: Extcon: support notification based on the state changes. State changes of extcon devices have been notified via kobjet_uevent. This patch adds notifier interfaces in order to allow device drivers to get notified easily. Along with notifier interface, extcon_get_extcon_dev() function is added so that device drivers may discover a extcon_dev easily. Signed-off-by: Donggeun Kim Signed-off-by: MyungJoo Ham Signed-off-by: Kyungmin Park Reviewed-by: Mark Brown -- Changes from RFC - Renamed switch to extcon - Bugfix: extcon_dev_unregister() - Bugfix: "edev->dev" is "internal" data. - Added kerneldoc comments. - Reworded comments. Signed-off-by: Greg Kroah-Hartman --- include/linux/extcon.h | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) (limited to 'include/linux/extcon.h') diff --git a/include/linux/extcon.h b/include/linux/extcon.h index 9cb3aaaf67f5..c9c9afe12b47 100644 --- a/include/linux/extcon.h +++ b/include/linux/extcon.h @@ -23,6 +23,7 @@ #ifndef __LINUX_EXTCON_H__ #define __LINUX_EXTCON_H__ +#include /** * struct extcon_dev - An extcon device represents one external connector. * @name The name of this extcon device. Parent device name is used @@ -34,6 +35,9 @@ * @dev Device of this extcon. Do not provide at register-time. * @state Attach/detach state of this extcon. Do not provide at * register-time + * @nh Notifier for the state change events from this extcon + * @entry To support list of extcon devices so that uses can search + * for extcon devices based on the extcon name. * * In most cases, users only need to provide "User initializing data" of * this struct when registering an extcon. In some exceptional cases, @@ -51,11 +55,19 @@ struct extcon_dev { /* --- Internal data. Please do not set. --- */ struct device *dev; u32 state; + struct raw_notifier_head nh; + struct list_head entry; }; #if IS_ENABLED(CONFIG_EXTCON) + +/* + * Following APIs are for notifiers or configurations. + * Notifiers are the external port and connection devices. + */ extern int extcon_dev_register(struct extcon_dev *edev, struct device *dev); extern void extcon_dev_unregister(struct extcon_dev *edev); +extern struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name); static inline u32 extcon_get_state(struct extcon_dev *edev) { @@ -63,6 +75,15 @@ static inline u32 extcon_get_state(struct extcon_dev *edev) } extern void extcon_set_state(struct extcon_dev *edev, u32 state); + +/* + * Following APIs are to monitor every action of a notifier. + * Registerer gets notified for every external port of a connection device. + */ +extern int extcon_register_notifier(struct extcon_dev *edev, + struct notifier_block *nb); +extern int extcon_unregister_notifier(struct extcon_dev *edev, + struct notifier_block *nb); #else /* CONFIG_EXTCON */ static inline int extcon_dev_register(struct extcon_dev *edev, struct device *dev) @@ -78,5 +99,22 @@ static inline u32 extcon_get_state(struct extcon_dev *edev) } static inline void extcon_set_state(struct extcon_dev *edev, u32 state) { } +static inline struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name) +{ + return NULL; +} + +static inline int extcon_register_notifier(struct extcon_dev *edev, + struct notifier_block *nb) +{ + return 0; +} + +static inline int extcon_unregister_notifier(struct extcon_dev *edev, + struct notifier_block *nb) +{ + return 0; +} + #endif /* CONFIG_EXTCON */ #endif /* __LINUX_EXTCON_H__ */ -- cgit v1.2.3