74c5d09bd5
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 <dg77.kim@samsung.com> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> -- 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 <gregkh@linuxfoundation.org>
121 lines
3.8 KiB
C
121 lines
3.8 KiB
C
/*
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* External connector (extcon) class driver
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*
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* Copyright (C) 2012 Samsung Electronics
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* Author: Donggeun Kim <dg77.kim@samsung.com>
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* Author: MyungJoo Ham <myungjoo.ham@samsung.com>
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*
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* based on switch class driver
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* Copyright (C) 2008 Google, Inc.
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* Author: Mike Lockwood <lockwood@android.com>
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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#ifndef __LINUX_EXTCON_H__
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#define __LINUX_EXTCON_H__
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#include <linux/notifier.h>
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/**
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* struct extcon_dev - An extcon device represents one external connector.
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* @name The name of this extcon device. Parent device name is used
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* if NULL.
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* @print_name An optional callback to override the method to print the
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* name of the extcon device.
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* @print_state An optional callback to override the method to print the
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* status of the extcon device.
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* @dev Device of this extcon. Do not provide at register-time.
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* @state Attach/detach state of this extcon. Do not provide at
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* register-time
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* @nh Notifier for the state change events from this extcon
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* @entry To support list of extcon devices so that uses can search
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* for extcon devices based on the extcon name.
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*
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* In most cases, users only need to provide "User initializing data" of
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* this struct when registering an extcon. In some exceptional cases,
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* optional callbacks may be needed. However, the values in "internal data"
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* are overwritten by register function.
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*/
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struct extcon_dev {
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/* --- Optional user initializing data --- */
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const char *name;
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/* --- Optional callbacks to override class functions --- */
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ssize_t (*print_name)(struct extcon_dev *edev, char *buf);
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ssize_t (*print_state)(struct extcon_dev *edev, char *buf);
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/* --- Internal data. Please do not set. --- */
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struct device *dev;
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u32 state;
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struct raw_notifier_head nh;
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struct list_head entry;
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};
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#if IS_ENABLED(CONFIG_EXTCON)
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/*
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* Following APIs are for notifiers or configurations.
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* Notifiers are the external port and connection devices.
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*/
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extern int extcon_dev_register(struct extcon_dev *edev, struct device *dev);
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extern void extcon_dev_unregister(struct extcon_dev *edev);
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extern struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name);
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static inline u32 extcon_get_state(struct extcon_dev *edev)
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{
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return edev->state;
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}
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extern void extcon_set_state(struct extcon_dev *edev, u32 state);
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/*
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* Following APIs are to monitor every action of a notifier.
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* Registerer gets notified for every external port of a connection device.
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*/
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extern int extcon_register_notifier(struct extcon_dev *edev,
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struct notifier_block *nb);
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extern int extcon_unregister_notifier(struct extcon_dev *edev,
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struct notifier_block *nb);
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#else /* CONFIG_EXTCON */
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static inline int extcon_dev_register(struct extcon_dev *edev,
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struct device *dev)
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{
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return 0;
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}
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static inline void extcon_dev_unregister(struct extcon_dev *edev) { }
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static inline u32 extcon_get_state(struct extcon_dev *edev)
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{
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return 0;
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}
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static inline void extcon_set_state(struct extcon_dev *edev, u32 state) { }
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static inline struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
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{
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return NULL;
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}
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static inline int extcon_register_notifier(struct extcon_dev *edev,
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struct notifier_block *nb)
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{
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return 0;
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}
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static inline int extcon_unregister_notifier(struct extcon_dev *edev,
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struct notifier_block *nb)
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{
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return 0;
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}
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#endif /* CONFIG_EXTCON */
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#endif /* __LINUX_EXTCON_H__ */
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