Initial import

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diff --git a/include/linux/extcon.h b/include/linux/extcon.h
new file mode 100644
index 000000000..36f49c405
--- /dev/null
+++ b/include/linux/extcon.h
@@ -0,0 +1,377 @@
+/*
+ *  External connector (extcon) class driver
+ *
+ * Copyright (C) 2012 Samsung Electronics
+ * Author: Donggeun Kim <dg77.kim@samsung.com>
+ * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * based on switch class driver
+ * Copyright (C) 2008 Google, Inc.
+ * Author: Mike Lockwood <lockwood@android.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+*/
+
+#ifndef __LINUX_EXTCON_H__
+#define __LINUX_EXTCON_H__
+
+#include <linux/device.h>
+#include <linux/notifier.h>
+#include <linux/sysfs.h>
+
+#define SUPPORTED_CABLE_MAX	32
+#define CABLE_NAME_MAX		30
+
+/*
+ * The standard cable name is to help support general notifier
+ * and notifiee device drivers to share the common names.
+ * Please use standard cable names unless your notifier device has
+ * a very unique and abnormal cable or
+ * the cable type is supposed to be used with only one unique
+ * pair of notifier/notifiee devices.
+ *
+ * Please add any other "standard" cables used with extcon dev.
+ *
+ * You may add a dot and number to specify version or specification
+ * of the specific cable if it is required. (e.g., "Fast-charger.18"
+ * and "Fast-charger.10" for 1.8A and 1.0A chargers)
+ * However, the notifiee and notifier should be able to handle such
+ * string and if the notifiee can negotiate the protocol or identify,
+ * you don't need such convention. This convention is helpful when
+ * notifier can distinguish but notifiee cannot.
+ */
+enum extcon_cable_name {
+	EXTCON_USB = 0,
+	EXTCON_USB_HOST,
+	EXTCON_TA,			/* Travel Adaptor */
+	EXTCON_FAST_CHARGER,
+	EXTCON_SLOW_CHARGER,
+	EXTCON_CHARGE_DOWNSTREAM,	/* Charging an external device */
+	EXTCON_HDMI,
+	EXTCON_MHL,
+	EXTCON_DVI,
+	EXTCON_VGA,
+	EXTCON_DOCK,
+	EXTCON_LINE_IN,
+	EXTCON_LINE_OUT,
+	EXTCON_MIC_IN,
+	EXTCON_HEADPHONE_OUT,
+	EXTCON_SPDIF_IN,
+	EXTCON_SPDIF_OUT,
+	EXTCON_VIDEO_IN,
+	EXTCON_VIDEO_OUT,
+	EXTCON_MECHANICAL,
+};
+extern const char extcon_cable_name[][CABLE_NAME_MAX + 1];
+
+struct extcon_cable;
+
+/**
+ * struct extcon_dev - An extcon device represents one external connector.
+ * @name:		The name of this extcon device. Parent device name is
+ *			used if NULL.
+ * @supported_cable:	Array of supported cable names ending with NULL.
+ *			If supported_cable is NULL, cable name related APIs
+ *			are disabled.
+ * @mutually_exclusive:	Array of mutually exclusive set of cables that cannot
+ *			be attached simultaneously. The array should be
+ *			ending with NULL or be NULL (no mutually exclusive
+ *			cables). For example, if it is { 0x7, 0x30, 0}, then,
+ *			{0, 1}, {0, 1, 2}, {0, 2}, {1, 2}, or {4, 5} cannot
+ *			be attached simulataneously. {0x7, 0} is equivalent to
+ *			{0x3, 0x6, 0x5, 0}. If it is {0xFFFFFFFF, 0}, there
+ *			can be no simultaneous connections.
+ * @print_name:		An optional callback to override the method to print the
+ *			name of the extcon device.
+ * @print_state:	An optional callback to override the method to print the
+ *			status of the extcon device.
+ * @dev:		Device of this extcon.
+ * @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 users can search
+ *			for extcon devices based on the extcon name.
+ * @lock:
+ * @max_supported:	Internal value to store the number of cables.
+ * @extcon_dev_type:	Device_type struct to provide attribute_groups
+ *			customized for each extcon device.
+ * @cables:		Sysfs subdirectories. Each represents one cable.
+ *
+ * In most cases, users only need to provide "User initializing data" of
+ * this struct when registering an extcon. In some exceptional cases,
+ * optional callbacks may be needed. However, the values in "internal data"
+ * are overwritten by register function.
+ */
+struct extcon_dev {
+	/* Optional user initializing data */
+	const char *name;
+	const char **supported_cable;
+	const u32 *mutually_exclusive;
+
+	/* Optional callbacks to override class functions */
+	ssize_t	(*print_name)(struct extcon_dev *edev, char *buf);
+	ssize_t	(*print_state)(struct extcon_dev *edev, char *buf);
+
+	/* Internal data. Please do not set. */
+	struct device dev;
+	struct raw_notifier_head nh;
+	struct list_head entry;
+	int max_supported;
+	spinlock_t lock;	/* could be called by irq handler */
+	u32 state;
+
+	/* /sys/class/extcon/.../cable.n/... */
+	struct device_type extcon_dev_type;
+	struct extcon_cable *cables;
+
+	/* /sys/class/extcon/.../mutually_exclusive/... */
+	struct attribute_group attr_g_muex;
+	struct attribute **attrs_muex;
+	struct device_attribute *d_attrs_muex;
+};
+
+/**
+ * struct extcon_cable - An internal data for each cable of extcon device.
+ * @edev:		The extcon device
+ * @cable_index:	Index of this cable in the edev
+ * @attr_g:		Attribute group for the cable
+ * @attr_name:		"name" sysfs entry
+ * @attr_state:		"state" sysfs entry
+ * @attrs:		Array pointing to attr_name and attr_state for attr_g
+ */
+struct extcon_cable {
+	struct extcon_dev *edev;
+	int cable_index;
+
+	struct attribute_group attr_g;
+	struct device_attribute attr_name;
+	struct device_attribute attr_state;
+
+	struct attribute *attrs[3]; /* to be fed to attr_g.attrs */
+};
+
+/**
+ * struct extcon_specific_cable_nb - An internal data for
+ *				     extcon_register_interest().
+ * @internal_nb:	A notifier block bridging extcon notifier
+ *			and cable notifier.
+ * @user_nb:		user provided notifier block for events from
+ *			a specific cable.
+ * @cable_index:	the target cable.
+ * @edev:		the target extcon device.
+ * @previous_value:	the saved previous event value.
+ */
+struct extcon_specific_cable_nb {
+	struct notifier_block internal_nb;
+	struct notifier_block *user_nb;
+	int cable_index;
+	struct extcon_dev *edev;
+	unsigned long previous_value;
+};
+
+#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);
+extern void extcon_dev_unregister(struct extcon_dev *edev);
+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);
+extern struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name);
+
+/*
+ * Following APIs control the memory of extcon device.
+ */
+extern struct extcon_dev *extcon_dev_allocate(const char **cables);
+extern void extcon_dev_free(struct extcon_dev *edev);
+extern struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
+						   const char **cables);
+extern void devm_extcon_dev_free(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
+ * are attached to the port.
+ */
+static inline u32 extcon_get_state(struct extcon_dev *edev)
+{
+	return edev->state;
+}
+
+extern int extcon_set_state(struct extcon_dev *edev, u32 state);
+extern int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state);
+
+/*
+ * get/set_cable_state access each bit of the 32b encoded state value.
+ * They are used to access the status of each cable based on the cable_name
+ * or cable_index, which is retrieved by extcon_find_cable_index
+ */
+extern int extcon_find_cable_index(struct extcon_dev *sdev,
+				   const char *cable_name);
+extern int extcon_get_cable_state_(struct extcon_dev *edev, int cable_index);
+extern int extcon_set_cable_state_(struct extcon_dev *edev, int cable_index,
+				   bool cable_state);
+
+extern int extcon_get_cable_state(struct extcon_dev *edev,
+				  const char *cable_name);
+extern int extcon_set_cable_state(struct extcon_dev *edev,
+				  const char *cable_name, bool cable_state);
+
+/*
+ * Following APIs are for notifiees (those who want to be notified)
+ * to register a callback for events from a specific cable of the extcon.
+ * Notifiees are the connected device drivers wanting to get notified by
+ * a specific external port of a connection device.
+ */
+extern int extcon_register_interest(struct extcon_specific_cable_nb *obj,
+				    const char *extcon_name,
+				    const char *cable_name,
+				    struct notifier_block *nb);
+extern int extcon_unregister_interest(struct extcon_specific_cable_nb *nb);
+
+/*
+ * Following APIs are to monitor every action of a notifier.
+ * Registrar gets notified for every external port of a connection device.
+ * Probably this could be used to debug an action of notifier; however,
+ * we do not recommend to use this for normal 'notifiee' device drivers who
+ * want to be notified by a specific external port of the notifier.
+ */
+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);
+
+/*
+ * Following API get the extcon device from devicetree.
+ * This function use phandle of devicetree to get extcon device directly.
+ */
+extern struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index);
+#else /* CONFIG_EXTCON */
+static inline int extcon_dev_register(struct extcon_dev *edev)
+{
+	return 0;
+}
+
+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 struct extcon_dev *extcon_dev_allocate(const char **cables)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
+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(-ENOSYS);
+}
+
+static inline void devm_extcon_dev_free(struct extcon_dev *edev) { }
+
+static inline u32 extcon_get_state(struct extcon_dev *edev)
+{
+	return 0;
+}
+
+static inline int extcon_set_state(struct extcon_dev *edev, u32 state)
+{
+	return 0;
+}
+
+static inline int extcon_update_state(struct extcon_dev *edev, u32 mask,
+				       u32 state)
+{
+	return 0;
+}
+
+static inline int extcon_find_cable_index(struct extcon_dev *edev,
+					  const char *cable_name)
+{
+	return 0;
+}
+
+static inline int extcon_get_cable_state_(struct extcon_dev *edev,
+					  int cable_index)
+{
+	return 0;
+}
+
+static inline int extcon_set_cable_state_(struct extcon_dev *edev,
+					  int cable_index, bool cable_state)
+{
+	return 0;
+}
+
+static inline int extcon_get_cable_state(struct extcon_dev *edev,
+			const char *cable_name)
+{
+	return 0;
+}
+
+static inline int extcon_set_cable_state(struct extcon_dev *edev,
+			const char *cable_name, int state)
+{
+	return 0;
+}
+
+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;
+}
+
+static inline int extcon_register_interest(struct extcon_specific_cable_nb *obj,
+					   const char *extcon_name,
+					   const char *cable_name,
+					   struct notifier_block *nb)
+{
+	return 0;
+}
+
+static inline int extcon_unregister_interest(struct extcon_specific_cable_nb
+						    *obj)
+{
+	return 0;
+}
+
+static inline struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev,
+							    int index)
+{
+	return ERR_PTR(-ENODEV);
+}
+#endif /* CONFIG_EXTCON */
+#endif /* __LINUX_EXTCON_H__ */