Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1494 insertions, 0 deletions

diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c
new file mode 100644
index 0000000000..6f7a60d2ed
--- /dev/null
+++ b/drivers/extcon/extcon.c
@@ -0,0 +1,1494 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * drivers/extcon/extcon.c - External Connector (extcon) framework.
+ *
+ * Copyright (C) 2015 Samsung Electronics
+ * Author: Chanwoo Choi <cw00.choi@samsung.com>
+ *
+ * Copyright (C) 2012 Samsung Electronics
+ * Author: Donggeun Kim <dg77.kim@samsung.com>
+ * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * based on android/drivers/switch/switch_class.c
+ * Copyright (C) 2008 Google, Inc.
+ * Author: Mike Lockwood <lockwood@android.com>
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+
+#include "extcon.h"
+
+#define SUPPORTED_CABLE_MAX	32
+
+static const struct __extcon_info {
+	unsigned int type;
+	unsigned int id;
+	const char *name;
+
+} extcon_info[] = {
+	[EXTCON_NONE] = {
+		.type = EXTCON_TYPE_MISC,
+		.id = EXTCON_NONE,
+		.name = "NONE",
+	},
+
+	/* USB external connector */
+	[EXTCON_USB] = {
+		.type = EXTCON_TYPE_USB,
+		.id = EXTCON_USB,
+		.name = "USB",
+	},
+	[EXTCON_USB_HOST] = {
+		.type = EXTCON_TYPE_USB,
+		.id = EXTCON_USB_HOST,
+		.name = "USB-HOST",
+	},
+
+	/* Charging external connector */
+	[EXTCON_CHG_USB_SDP] = {
+		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
+		.id = EXTCON_CHG_USB_SDP,
+		.name = "SDP",
+	},
+	[EXTCON_CHG_USB_DCP] = {
+		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
+		.id = EXTCON_CHG_USB_DCP,
+		.name = "DCP",
+	},
+	[EXTCON_CHG_USB_CDP] = {
+		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
+		.id = EXTCON_CHG_USB_CDP,
+		.name = "CDP",
+	},
+	[EXTCON_CHG_USB_ACA] = {
+		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
+		.id = EXTCON_CHG_USB_ACA,
+		.name = "ACA",
+	},
+	[EXTCON_CHG_USB_FAST] = {
+		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
+		.id = EXTCON_CHG_USB_FAST,
+		.name = "FAST-CHARGER",
+	},
+	[EXTCON_CHG_USB_SLOW] = {
+		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
+		.id = EXTCON_CHG_USB_SLOW,
+		.name = "SLOW-CHARGER",
+	},
+	[EXTCON_CHG_WPT] = {
+		.type = EXTCON_TYPE_CHG,
+		.id = EXTCON_CHG_WPT,
+		.name = "WPT",
+	},
+	[EXTCON_CHG_USB_PD] = {
+		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
+		.id = EXTCON_CHG_USB_PD,
+		.name = "PD",
+	},
+
+	/* Jack external connector */
+	[EXTCON_JACK_MICROPHONE] = {
+		.type = EXTCON_TYPE_JACK,
+		.id = EXTCON_JACK_MICROPHONE,
+		.name = "MICROPHONE",
+	},
+	[EXTCON_JACK_HEADPHONE] = {
+		.type = EXTCON_TYPE_JACK,
+		.id = EXTCON_JACK_HEADPHONE,
+		.name = "HEADPHONE",
+	},
+	[EXTCON_JACK_LINE_IN] = {
+		.type = EXTCON_TYPE_JACK,
+		.id = EXTCON_JACK_LINE_IN,
+		.name = "LINE-IN",
+	},
+	[EXTCON_JACK_LINE_OUT] = {
+		.type = EXTCON_TYPE_JACK,
+		.id = EXTCON_JACK_LINE_OUT,
+		.name = "LINE-OUT",
+	},
+	[EXTCON_JACK_VIDEO_IN] = {
+		.type = EXTCON_TYPE_JACK,
+		.id = EXTCON_JACK_VIDEO_IN,
+		.name = "VIDEO-IN",
+	},
+	[EXTCON_JACK_VIDEO_OUT] = {
+		.type = EXTCON_TYPE_JACK,
+		.id = EXTCON_JACK_VIDEO_OUT,
+		.name = "VIDEO-OUT",
+	},
+	[EXTCON_JACK_SPDIF_IN] = {
+		.type = EXTCON_TYPE_JACK,
+		.id = EXTCON_JACK_SPDIF_IN,
+		.name = "SPDIF-IN",
+	},
+	[EXTCON_JACK_SPDIF_OUT] = {
+		.type = EXTCON_TYPE_JACK,
+		.id = EXTCON_JACK_SPDIF_OUT,
+		.name = "SPDIF-OUT",
+	},
+
+	/* Display external connector */
+	[EXTCON_DISP_HDMI] = {
+		.type = EXTCON_TYPE_DISP,
+		.id = EXTCON_DISP_HDMI,
+		.name = "HDMI",
+	},
+	[EXTCON_DISP_MHL] = {
+		.type = EXTCON_TYPE_DISP,
+		.id = EXTCON_DISP_MHL,
+		.name = "MHL",
+	},
+	[EXTCON_DISP_DVI] = {
+		.type = EXTCON_TYPE_DISP,
+		.id = EXTCON_DISP_DVI,
+		.name = "DVI",
+	},
+	[EXTCON_DISP_VGA] = {
+		.type = EXTCON_TYPE_DISP,
+		.id = EXTCON_DISP_VGA,
+		.name = "VGA",
+	},
+	[EXTCON_DISP_DP] = {
+		.type = EXTCON_TYPE_DISP | EXTCON_TYPE_USB,
+		.id = EXTCON_DISP_DP,
+		.name = "DP",
+	},
+	[EXTCON_DISP_HMD] = {
+		.type = EXTCON_TYPE_DISP | EXTCON_TYPE_USB,
+		.id = EXTCON_DISP_HMD,
+		.name = "HMD",
+	},
+	[EXTCON_DISP_CVBS] = {
+		.type = EXTCON_TYPE_DISP,
+		.id = EXTCON_DISP_CVBS,
+		.name = "CVBS",
+	},
+	[EXTCON_DISP_EDP] = {
+		.type = EXTCON_TYPE_DISP,
+		.id = EXTCON_DISP_EDP,
+		.name = "EDP",
+	},
+
+	/* Miscellaneous external connector */
+	[EXTCON_DOCK] = {
+		.type = EXTCON_TYPE_MISC,
+		.id = EXTCON_DOCK,
+		.name = "DOCK",
+	},
+	[EXTCON_JIG] = {
+		.type = EXTCON_TYPE_MISC,
+		.id = EXTCON_JIG,
+		.name = "JIG",
+	},
+	[EXTCON_MECHANICAL] = {
+		.type = EXTCON_TYPE_MISC,
+		.id = EXTCON_MECHANICAL,
+		.name = "MECHANICAL",
+	},
+
+	{ /* sentinel */ }
+};
+
+/**
+ * struct extcon_cable - An internal data for an external connector.
+ * @edev:		the extcon device
+ * @cable_index:	the index of this cable in the edev
+ * @attr_g:		the attribute group for the cable
+ * @attr_name:		"name" sysfs entry
+ * @attr_state:		"state" sysfs entry
+ * @attrs:		the array pointing to attr_name and attr_state for attr_g
+ * @usb_propval:	the array of USB connector properties
+ * @chg_propval:	the array of charger connector properties
+ * @jack_propval:	the array of jack connector properties
+ * @disp_propval:	the array of display connector properties
+ * @usb_bits:		the bit array of the USB connector property capabilities
+ * @chg_bits:		the bit array of the charger connector property capabilities
+ * @jack_bits:		the bit array of the jack connector property capabilities
+ * @disp_bits:		the bit array of the display connector property capabilities
+ */
+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 */
+
+	union extcon_property_value usb_propval[EXTCON_PROP_USB_CNT];
+	union extcon_property_value chg_propval[EXTCON_PROP_CHG_CNT];
+	union extcon_property_value jack_propval[EXTCON_PROP_JACK_CNT];
+	union extcon_property_value disp_propval[EXTCON_PROP_DISP_CNT];
+
+	DECLARE_BITMAP(usb_bits, EXTCON_PROP_USB_CNT);
+	DECLARE_BITMAP(chg_bits, EXTCON_PROP_CHG_CNT);
+	DECLARE_BITMAP(jack_bits, EXTCON_PROP_JACK_CNT);
+	DECLARE_BITMAP(disp_bits, EXTCON_PROP_DISP_CNT);
+};
+
+static struct class *extcon_class;
+
+static DEFINE_IDA(extcon_dev_ids);
+static LIST_HEAD(extcon_dev_list);
+static DEFINE_MUTEX(extcon_dev_list_lock);
+
+static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
+{
+	int i;
+
+	if (!edev->mutually_exclusive)
+		return 0;
+
+	for (i = 0; edev->mutually_exclusive[i]; i++) {
+		int weight;
+		u32 correspondants = new_state & edev->mutually_exclusive[i];
+
+		/* calculate the total number of bits set */
+		weight = hweight32(correspondants);
+		if (weight > 1)
+			return i + 1;
+	}
+
+	return 0;
+}
+
+static int find_cable_index_by_id(struct extcon_dev *edev, const unsigned int id)
+{
+	int i;
+
+	/* Find the index of extcon cable in edev->supported_cable */
+	for (i = 0; i < edev->max_supported; i++) {
+		if (edev->supported_cable[i] == id)
+			return i;
+	}
+
+	return -EINVAL;
+}
+
+static int get_extcon_type(unsigned int prop)
+{
+	switch (prop) {
+	case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
+		return EXTCON_TYPE_USB;
+	case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
+		return EXTCON_TYPE_CHG;
+	case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
+		return EXTCON_TYPE_JACK;
+	case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
+		return EXTCON_TYPE_DISP;
+	default:
+		return -EINVAL;
+	}
+}
+
+static bool is_extcon_attached(struct extcon_dev *edev, unsigned int index)
+{
+	return !!(edev->state & BIT(index));
+}
+
+static bool is_extcon_changed(struct extcon_dev *edev, int index,
+				bool new_state)
+{
+	int state = !!(edev->state & BIT(index));
+	return (state != new_state);
+}
+
+static bool is_extcon_property_supported(unsigned int id, unsigned int prop)
+{
+	int type;
+
+	/* Check whether the property is supported or not. */
+	type = get_extcon_type(prop);
+	if (type < 0)
+		return false;
+
+	/* Check whether a specific extcon id supports the property or not. */
+	return !!(extcon_info[id].type & type);
+}
+
+static int is_extcon_property_capability(struct extcon_dev *edev,
+				unsigned int id, int index,unsigned int prop)
+{
+	struct extcon_cable *cable;
+	int type, ret;
+
+	/* Check whether the property is supported or not. */
+	type = get_extcon_type(prop);
+	if (type < 0)
+		return type;
+
+	cable = &edev->cables[index];
+
+	switch (type) {
+	case EXTCON_TYPE_USB:
+		ret = test_bit(prop - EXTCON_PROP_USB_MIN, cable->usb_bits);
+		break;
+	case EXTCON_TYPE_CHG:
+		ret = test_bit(prop - EXTCON_PROP_CHG_MIN, cable->chg_bits);
+		break;
+	case EXTCON_TYPE_JACK:
+		ret = test_bit(prop - EXTCON_PROP_JACK_MIN, cable->jack_bits);
+		break;
+	case EXTCON_TYPE_DISP:
+		ret = test_bit(prop - EXTCON_PROP_DISP_MIN, cable->disp_bits);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static void init_property(struct extcon_dev *edev, unsigned int id, int index)
+{
+	unsigned int type = extcon_info[id].type;
+	struct extcon_cable *cable = &edev->cables[index];
+
+	if (EXTCON_TYPE_USB & type)
+		memset(cable->usb_propval, 0, sizeof(cable->usb_propval));
+	if (EXTCON_TYPE_CHG & type)
+		memset(cable->chg_propval, 0, sizeof(cable->chg_propval));
+	if (EXTCON_TYPE_JACK & type)
+		memset(cable->jack_propval, 0, sizeof(cable->jack_propval));
+	if (EXTCON_TYPE_DISP & type)
+		memset(cable->disp_propval, 0, sizeof(cable->disp_propval));
+}
+
+static ssize_t state_show(struct device *dev, struct device_attribute *attr,
+			  char *buf)
+{
+	int i, count = 0;
+	struct extcon_dev *edev = dev_get_drvdata(dev);
+
+	if (edev->max_supported == 0)
+		return sysfs_emit(buf, "%u\n", edev->state);
+
+	for (i = 0; i < edev->max_supported; i++) {
+		count += sysfs_emit_at(buf, count, "%s=%d\n",
+				       extcon_info[edev->supported_cable[i]].name,
+				       !!(edev->state & BIT(i)));
+	}
+
+	return count;
+}
+static DEVICE_ATTR_RO(state);
+
+static ssize_t name_show(struct device *dev, struct device_attribute *attr,
+		char *buf)
+{
+	struct extcon_dev *edev = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%s\n", edev->name);
+}
+static DEVICE_ATTR_RO(name);
+
+static ssize_t cable_name_show(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	struct extcon_cable *cable = container_of(attr, struct extcon_cable,
+						  attr_name);
+	int i = cable->cable_index;
+
+	return sysfs_emit(buf, "%s\n",
+			  extcon_info[cable->edev->supported_cable[i]].name);
+}
+
+static ssize_t cable_state_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct extcon_cable *cable = container_of(attr, struct extcon_cable,
+						  attr_state);
+
+	int i = cable->cable_index;
+
+	return sysfs_emit(buf, "%d\n",
+			  extcon_get_state(cable->edev, cable->edev->supported_cable[i]));
+}
+
+/**
+ * extcon_sync() - Synchronize the state for an external connector.
+ * @edev:	the extcon device
+ * @id:		the unique id indicating an external connector
+ *
+ * Note that this function send a notification in order to synchronize
+ * the state and property of an external connector.
+ *
+ * Returns 0 if success or error number if fail.
+ */
+int extcon_sync(struct extcon_dev *edev, unsigned int id)
+{
+	char name_buf[120];
+	char state_buf[120];
+	char *prop_buf;
+	char *envp[3];
+	int env_offset = 0;
+	int length;
+	int index;
+	int state;
+	unsigned long flags;
+
+	if (!edev)
+		return -EINVAL;
+
+	index = find_cable_index_by_id(edev, id);
+	if (index < 0)
+		return index;
+
+	spin_lock_irqsave(&edev->lock, flags);
+	state = !!(edev->state & BIT(index));
+	spin_unlock_irqrestore(&edev->lock, flags);
+
+	/*
+	 * Call functions in a raw notifier chain for the specific one
+	 * external connector.
+	 */
+	raw_notifier_call_chain(&edev->nh[index], state, edev);
+
+	/*
+	 * Call functions in a raw notifier chain for the all supported
+	 * external connectors.
+	 */
+	raw_notifier_call_chain(&edev->nh_all, state, edev);
+
+	spin_lock_irqsave(&edev->lock, flags);
+	/* This could be in interrupt handler */
+	prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
+	if (!prop_buf) {
+		/* Unlock early before uevent */
+		spin_unlock_irqrestore(&edev->lock, flags);
+
+		dev_err(&edev->dev, "out of memory in extcon_set_state\n");
+		kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
+
+		return -ENOMEM;
+	}
+
+	length = name_show(&edev->dev, NULL, prop_buf);
+	if (length > 0) {
+		if (prop_buf[length - 1] == '\n')
+			prop_buf[length - 1] = 0;
+		snprintf(name_buf, sizeof(name_buf), "NAME=%s", prop_buf);
+		envp[env_offset++] = name_buf;
+	}
+
+	length = state_show(&edev->dev, NULL, prop_buf);
+	if (length > 0) {
+		if (prop_buf[length - 1] == '\n')
+			prop_buf[length - 1] = 0;
+		snprintf(state_buf, sizeof(state_buf), "STATE=%s", prop_buf);
+		envp[env_offset++] = state_buf;
+	}
+	envp[env_offset] = NULL;
+
+	/* Unlock early before uevent */
+	spin_unlock_irqrestore(&edev->lock, flags);
+	kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
+	free_page((unsigned long)prop_buf);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(extcon_sync);
+
+/**
+ * extcon_get_state() - Get the state of an external connector.
+ * @edev:	the extcon device
+ * @id:		the unique id indicating an external connector
+ *
+ * Returns 0 if success or error number if fail.
+ */
+int extcon_get_state(struct extcon_dev *edev, const unsigned int id)
+{
+	int index, state;
+	unsigned long flags;
+
+	if (!edev)
+		return -EINVAL;
+
+	index = find_cable_index_by_id(edev, id);
+	if (index < 0)
+		return index;
+
+	spin_lock_irqsave(&edev->lock, flags);
+	state = is_extcon_attached(edev, index);
+	spin_unlock_irqrestore(&edev->lock, flags);
+
+	return state;
+}
+EXPORT_SYMBOL_GPL(extcon_get_state);
+
+/**
+ * extcon_set_state() - Set the state of an external connector.
+ * @edev:	the extcon device
+ * @id:		the unique id indicating an external connector
+ * @state:	the new state of an external connector.
+ *		the default semantics is true: attached / false: detached.
+ *
+ * Note that this function set the state of an external connector without
+ * a notification. To synchronize the state of an external connector,
+ * have to use extcon_set_state_sync() and extcon_sync().
+ *
+ * Returns 0 if success or error number if fail.
+ */
+int extcon_set_state(struct extcon_dev *edev, unsigned int id, bool state)
+{
+	unsigned long flags;
+	int index, ret = 0;
+
+	if (!edev)
+		return -EINVAL;
+
+	index = find_cable_index_by_id(edev, id);
+	if (index < 0)
+		return index;
+
+	spin_lock_irqsave(&edev->lock, flags);
+
+	/* Check whether the external connector's state is changed. */
+	if (!is_extcon_changed(edev, index, state))
+		goto out;
+
+	if (check_mutually_exclusive(edev,
+		(edev->state & ~BIT(index)) | (state & BIT(index)))) {
+		ret = -EPERM;
+		goto out;
+	}
+
+	/*
+	 * Initialize the value of extcon property before setting
+	 * the detached state for an external connector.
+	 */
+	if (!state)
+		init_property(edev, id, index);
+
+	/* Update the state for an external connector. */
+	if (state)
+		edev->state |= BIT(index);
+	else
+		edev->state &= ~(BIT(index));
+out:
+	spin_unlock_irqrestore(&edev->lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(extcon_set_state);
+
+/**
+ * extcon_set_state_sync() - Set the state of an external connector with sync.
+ * @edev:	the extcon device
+ * @id:		the unique id indicating an external connector
+ * @state:	the new state of external connector.
+ *		the default semantics is true: attached / false: detached.
+ *
+ * Note that this function set the state of external connector
+ * and synchronize the state by sending a notification.
+ *
+ * Returns 0 if success or error number if fail.
+ */
+int extcon_set_state_sync(struct extcon_dev *edev, unsigned int id, bool state)
+{
+	int ret;
+
+	ret = extcon_set_state(edev, id, state);
+	if (ret < 0)
+		return ret;
+
+	return extcon_sync(edev, id);
+}
+EXPORT_SYMBOL_GPL(extcon_set_state_sync);
+
+/**
+ * extcon_get_property() - Get the property value of an external connector.
+ * @edev:	the extcon device
+ * @id:		the unique id indicating an external connector
+ * @prop:	the property id indicating an extcon property
+ * @prop_val:	the pointer which store the value of extcon property
+ *
+ * Note that when getting the property value of external connector,
+ * the external connector should be attached. If detached state, function
+ * return 0 without property value. Also, the each property should be
+ * included in the list of supported properties according to extcon type.
+ *
+ * Returns 0 if success or error number if fail.
+ */
+int extcon_get_property(struct extcon_dev *edev, unsigned int id,
+				unsigned int prop,
+				union extcon_property_value *prop_val)
+{
+	struct extcon_cable *cable;
+	unsigned long flags;
+	int index, ret = 0;
+
+	*prop_val = (union extcon_property_value){0};
+
+	if (!edev)
+		return -EINVAL;
+
+	/* Check whether the property is supported or not */
+	if (!is_extcon_property_supported(id, prop))
+		return -EINVAL;
+
+	/* Find the cable index of external connector by using id */
+	index = find_cable_index_by_id(edev, id);
+	if (index < 0)
+		return index;
+
+	spin_lock_irqsave(&edev->lock, flags);
+
+	/* Check whether the property is available or not. */
+	if (!is_extcon_property_capability(edev, id, index, prop)) {
+		spin_unlock_irqrestore(&edev->lock, flags);
+		return -EPERM;
+	}
+
+	/*
+	 * Check whether the external connector is attached.
+	 * If external connector is detached, the user can not
+	 * get the property value.
+	 */
+	if (!is_extcon_attached(edev, index)) {
+		spin_unlock_irqrestore(&edev->lock, flags);
+		return 0;
+	}
+
+	cable = &edev->cables[index];
+
+	/* Get the property value according to extcon type */
+	switch (prop) {
+	case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
+		*prop_val = cable->usb_propval[prop - EXTCON_PROP_USB_MIN];
+		break;
+	case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
+		*prop_val = cable->chg_propval[prop - EXTCON_PROP_CHG_MIN];
+		break;
+	case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
+		*prop_val = cable->jack_propval[prop - EXTCON_PROP_JACK_MIN];
+		break;
+	case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
+		*prop_val = cable->disp_propval[prop - EXTCON_PROP_DISP_MIN];
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	spin_unlock_irqrestore(&edev->lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(extcon_get_property);
+
+/**
+ * extcon_set_property() - Set the property value of an external connector.
+ * @edev:	the extcon device
+ * @id:		the unique id indicating an external connector
+ * @prop:	the property id indicating an extcon property
+ * @prop_val:	the pointer including the new value of extcon property
+ *
+ * Note that each property should be included in the list of supported
+ * properties according to the extcon type.
+ *
+ * Returns 0 if success or error number if fail.
+ */
+int extcon_set_property(struct extcon_dev *edev, unsigned int id,
+				unsigned int prop,
+				union extcon_property_value prop_val)
+{
+	struct extcon_cable *cable;
+	unsigned long flags;
+	int index, ret = 0;
+
+	if (!edev)
+		return -EINVAL;
+
+	/* Check whether the property is supported or not */
+	if (!is_extcon_property_supported(id, prop))
+		return -EINVAL;
+
+	/* Find the cable index of external connector by using id */
+	index = find_cable_index_by_id(edev, id);
+	if (index < 0)
+		return index;
+
+	spin_lock_irqsave(&edev->lock, flags);
+
+	/* Check whether the property is available or not. */
+	if (!is_extcon_property_capability(edev, id, index, prop)) {
+		spin_unlock_irqrestore(&edev->lock, flags);
+		return -EPERM;
+	}
+
+	cable = &edev->cables[index];
+
+	/* Set the property value according to extcon type */
+	switch (prop) {
+	case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
+		cable->usb_propval[prop - EXTCON_PROP_USB_MIN] = prop_val;
+		break;
+	case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
+		cable->chg_propval[prop - EXTCON_PROP_CHG_MIN] = prop_val;
+		break;
+	case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
+		cable->jack_propval[prop - EXTCON_PROP_JACK_MIN] = prop_val;
+		break;
+	case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
+		cable->disp_propval[prop - EXTCON_PROP_DISP_MIN] = prop_val;
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	spin_unlock_irqrestore(&edev->lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(extcon_set_property);
+
+/**
+ * extcon_set_property_sync() - Set property of an external connector with sync.
+ * @edev:	the extcon device
+ * @id:		the unique id indicating an external connector
+ * @prop:	the property id indicating an extcon property
+ * @prop_val:	the pointer including the new value of extcon property
+ *
+ * Note that when setting the property value of external connector,
+ * the external connector should be attached. The each property should
+ * be included in the list of supported properties according to extcon type.
+ *
+ * Returns 0 if success or error number if fail.
+ */
+int extcon_set_property_sync(struct extcon_dev *edev, unsigned int id,
+				unsigned int prop,
+				union extcon_property_value prop_val)
+{
+	int ret;
+
+	ret = extcon_set_property(edev, id, prop, prop_val);
+	if (ret < 0)
+		return ret;
+
+	return extcon_sync(edev, id);
+}
+EXPORT_SYMBOL_GPL(extcon_set_property_sync);
+
+/**
+ * extcon_get_property_capability() - Get the capability of the property
+ *					for an external connector.
+ * @edev:	the extcon device
+ * @id:		the unique id indicating an external connector
+ * @prop:	the property id indicating an extcon property
+ *
+ * Returns 1 if the property is available or 0 if not available.
+ */
+int extcon_get_property_capability(struct extcon_dev *edev, unsigned int id,
+					unsigned int prop)
+{
+	int index;
+
+	if (!edev)
+		return -EINVAL;
+
+	/* Check whether the property is supported or not */
+	if (!is_extcon_property_supported(id, prop))
+		return -EINVAL;
+
+	/* Find the cable index of external connector by using id */
+	index = find_cable_index_by_id(edev, id);
+	if (index < 0)
+		return index;
+
+	return is_extcon_property_capability(edev, id, index, prop);
+}
+EXPORT_SYMBOL_GPL(extcon_get_property_capability);
+
+/**
+ * extcon_set_property_capability() - Set the capability of the property
+ *					for an external connector.
+ * @edev:	the extcon device
+ * @id:		the unique id indicating an external connector
+ * @prop:	the property id indicating an extcon property
+ *
+ * Note that this function set the capability of the property
+ * for an external connector in order to mark the bit in capability
+ * bitmap which mean the available state of the property.
+ *
+ * Returns 0 if success or error number if fail.
+ */
+int extcon_set_property_capability(struct extcon_dev *edev, unsigned int id,
+					unsigned int prop)
+{
+	struct extcon_cable *cable;
+	int index, type, ret = 0;
+
+	if (!edev)
+		return -EINVAL;
+
+	/* Check whether the property is supported or not. */
+	if (!is_extcon_property_supported(id, prop))
+		return -EINVAL;
+
+	/* Find the cable index of external connector by using id. */
+	index = find_cable_index_by_id(edev, id);
+	if (index < 0)
+		return index;
+
+	type = get_extcon_type(prop);
+	if (type < 0)
+		return type;
+
+	cable = &edev->cables[index];
+
+	switch (type) {
+	case EXTCON_TYPE_USB:
+		__set_bit(prop - EXTCON_PROP_USB_MIN, cable->usb_bits);
+		break;
+	case EXTCON_TYPE_CHG:
+		__set_bit(prop - EXTCON_PROP_CHG_MIN, cable->chg_bits);
+		break;
+	case EXTCON_TYPE_JACK:
+		__set_bit(prop - EXTCON_PROP_JACK_MIN, cable->jack_bits);
+		break;
+	case EXTCON_TYPE_DISP:
+		__set_bit(prop - EXTCON_PROP_DISP_MIN, cable->disp_bits);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(extcon_set_property_capability);
+
+/**
+ * extcon_get_extcon_dev() - Get the extcon device instance from the name.
+ * @extcon_name:	the extcon name provided with extcon_dev_register()
+ *
+ * Return the pointer of extcon device if success or ERR_PTR(err) if fail.
+ * NOTE: This function returns -EPROBE_DEFER so it may only be called from
+ * probe() functions.
+ */
+struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
+{
+	struct extcon_dev *sd;
+
+	if (!extcon_name)
+		return ERR_PTR(-EINVAL);
+
+	mutex_lock(&extcon_dev_list_lock);
+	list_for_each_entry(sd, &extcon_dev_list, entry) {
+		if (!strcmp(sd->name, extcon_name))
+			goto out;
+	}
+	sd = ERR_PTR(-EPROBE_DEFER);
+out:
+	mutex_unlock(&extcon_dev_list_lock);
+	return sd;
+}
+EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
+
+/**
+ * extcon_register_notifier() - Register a notifier block to get notified by
+ *				any state changes from the extcon.
+ * @edev:	the extcon device
+ * @id:		the unique id indicating an external connector
+ * @nb:		a notifier block to be registered
+ *
+ * Note that the second parameter given to the callback of nb (val) is
+ * the current state of an external connector and the third pameter
+ * is the pointer of extcon device.
+ *
+ * Returns 0 if success or error number if fail.
+ */
+int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
+			     struct notifier_block *nb)
+{
+	unsigned long flags;
+	int ret, idx;
+
+	if (!edev || !nb)
+		return -EINVAL;
+
+	idx = find_cable_index_by_id(edev, id);
+	if (idx < 0)
+		return idx;
+
+	spin_lock_irqsave(&edev->lock, flags);
+	ret = raw_notifier_chain_register(&edev->nh[idx], nb);
+	spin_unlock_irqrestore(&edev->lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(extcon_register_notifier);
+
+/**
+ * extcon_unregister_notifier() - Unregister a notifier block from the extcon.
+ * @edev:	the extcon device
+ * @id:		the unique id indicating an external connector
+ * @nb:		a notifier block to be registered
+ *
+ * Returns 0 if success or error number if fail.
+ */
+int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
+				struct notifier_block *nb)
+{
+	unsigned long flags;
+	int ret, idx;
+
+	if (!edev || !nb)
+		return -EINVAL;
+
+	idx = find_cable_index_by_id(edev, id);
+	if (idx < 0)
+		return idx;
+
+	spin_lock_irqsave(&edev->lock, flags);
+	ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);
+	spin_unlock_irqrestore(&edev->lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
+
+/**
+ * extcon_register_notifier_all() - Register a notifier block for all connectors.
+ * @edev:	the extcon device
+ * @nb:		a notifier block to be registered
+ *
+ * Note that this function registers a notifier block in order to receive
+ * the state change of all supported external connectors from extcon device.
+ * And the second parameter given to the callback of nb (val) is
+ * the current state and the third pameter is the pointer of extcon device.
+ *
+ * Returns 0 if success or error number if fail.
+ */
+int extcon_register_notifier_all(struct extcon_dev *edev,
+				struct notifier_block *nb)
+{
+	unsigned long flags;
+	int ret;
+
+	if (!edev || !nb)
+		return -EINVAL;
+
+	spin_lock_irqsave(&edev->lock, flags);
+	ret = raw_notifier_chain_register(&edev->nh_all, nb);
+	spin_unlock_irqrestore(&edev->lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(extcon_register_notifier_all);
+
+/**
+ * extcon_unregister_notifier_all() - Unregister a notifier block from extcon.
+ * @edev:	the extcon device
+ * @nb:		a notifier block to be registered
+ *
+ * Returns 0 if success or error number if fail.
+ */
+int extcon_unregister_notifier_all(struct extcon_dev *edev,
+				struct notifier_block *nb)
+{
+	unsigned long flags;
+	int ret;
+
+	if (!edev || !nb)
+		return -EINVAL;
+
+	spin_lock_irqsave(&edev->lock, flags);
+	ret = raw_notifier_chain_unregister(&edev->nh_all, nb);
+	spin_unlock_irqrestore(&edev->lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(extcon_unregister_notifier_all);
+
+static struct attribute *extcon_attrs[] = {
+	&dev_attr_state.attr,
+	&dev_attr_name.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(extcon);
+
+static int create_extcon_class(void)
+{
+	if (extcon_class)
+		return 0;
+
+	extcon_class = class_create("extcon");
+	if (IS_ERR(extcon_class))
+		return PTR_ERR(extcon_class);
+	extcon_class->dev_groups = extcon_groups;
+
+	return 0;
+}
+
+static void extcon_dev_release(struct device *dev)
+{
+}
+
+static const char *muex_name = "mutually_exclusive";
+static void dummy_sysfs_dev_release(struct device *dev)
+{
+}
+
+/*
+ * extcon_dev_allocate() - Allocate the memory of extcon device.
+ * @supported_cable:	the array of the supported external connectors
+ *			ending with EXTCON_NONE.
+ *
+ * Note that this function allocates the memory for extcon device 
+ * and initialize default setting for the extcon device.
+ *
+ * Returns the pointer memory of allocated extcon_dev if success
+ * or ERR_PTR(err) if fail.
+ */
+struct extcon_dev *extcon_dev_allocate(const unsigned int *supported_cable)
+{
+	struct extcon_dev *edev;
+
+	if (!supported_cable)
+		return ERR_PTR(-EINVAL);
+
+	edev = kzalloc(sizeof(*edev), GFP_KERNEL);
+	if (!edev)
+		return ERR_PTR(-ENOMEM);
+
+	edev->max_supported = 0;
+	edev->supported_cable = supported_cable;
+
+	return edev;
+}
+
+/*
+ * extcon_dev_free() - Free the memory of extcon device.
+ * @edev:	the extcon device
+ */
+void extcon_dev_free(struct extcon_dev *edev)
+{
+	kfree(edev);
+}
+EXPORT_SYMBOL_GPL(extcon_dev_free);
+
+/**
+ * extcon_alloc_cables() - alloc the cables for extcon device
+ * @edev:	extcon device which has cables
+ *
+ * Returns 0 if success or error number if fail.
+ */
+static int extcon_alloc_cables(struct extcon_dev *edev)
+{
+	int index;
+	char *str;
+	struct extcon_cable *cable;
+
+	if (!edev)
+		return -EINVAL;
+
+	if (!edev->max_supported)
+		return 0;
+
+	edev->cables = kcalloc(edev->max_supported, sizeof(*edev->cables),
+			       GFP_KERNEL);
+	if (!edev->cables)
+		return -ENOMEM;
+
+	for (index = 0; index < edev->max_supported; index++) {
+		cable = &edev->cables[index];
+
+		str = kasprintf(GFP_KERNEL, "cable.%d", index);
+		if (!str) {
+			for (index--; index >= 0; index--) {
+				cable = &edev->cables[index];
+				kfree(cable->attr_g.name);
+			}
+
+			kfree(edev->cables);
+			return -ENOMEM;
+		}
+
+		cable->edev = edev;
+		cable->cable_index = index;
+		cable->attrs[0] = &cable->attr_name.attr;
+		cable->attrs[1] = &cable->attr_state.attr;
+		cable->attrs[2] = NULL;
+		cable->attr_g.name = str;
+		cable->attr_g.attrs = cable->attrs;
+
+		sysfs_attr_init(&cable->attr_name.attr);
+		cable->attr_name.attr.name = "name";
+		cable->attr_name.attr.mode = 0444;
+		cable->attr_name.show = cable_name_show;
+
+		sysfs_attr_init(&cable->attr_state.attr);
+		cable->attr_state.attr.name = "state";
+		cable->attr_state.attr.mode = 0444;
+		cable->attr_state.show = cable_state_show;
+	}
+
+	return 0;
+}
+
+/**
+ * extcon_alloc_muex() - alloc the mutual exclusive for extcon device
+ * @edev:	extcon device
+ *
+ * Returns 0 if success or error number if fail.
+ */
+static int extcon_alloc_muex(struct extcon_dev *edev)
+{
+	char *name;
+	int index;
+
+	if (!edev)
+		return -EINVAL;
+
+	if (!(edev->max_supported && edev->mutually_exclusive))
+		return 0;
+
+	/* Count the size of mutually_exclusive array */
+	for (index = 0; edev->mutually_exclusive[index]; index++)
+		;
+
+	edev->attrs_muex = kcalloc(index + 1, sizeof(*edev->attrs_muex),
+				   GFP_KERNEL);
+	if (!edev->attrs_muex)
+		return -ENOMEM;
+
+	edev->d_attrs_muex = kcalloc(index, sizeof(*edev->d_attrs_muex),
+				     GFP_KERNEL);
+	if (!edev->d_attrs_muex) {
+		kfree(edev->attrs_muex);
+		return -ENOMEM;
+	}
+
+	for (index = 0; edev->mutually_exclusive[index]; index++) {
+		name = kasprintf(GFP_KERNEL, "0x%x",
+				 edev->mutually_exclusive[index]);
+		if (!name) {
+			for (index--; index >= 0; index--)
+				kfree(edev->d_attrs_muex[index].attr.name);
+
+			kfree(edev->d_attrs_muex);
+			kfree(edev->attrs_muex);
+			return -ENOMEM;
+		}
+		sysfs_attr_init(&edev->d_attrs_muex[index].attr);
+		edev->d_attrs_muex[index].attr.name = name;
+		edev->d_attrs_muex[index].attr.mode = 0000;
+		edev->attrs_muex[index] = &edev->d_attrs_muex[index].attr;
+	}
+	edev->attr_g_muex.name = muex_name;
+	edev->attr_g_muex.attrs = edev->attrs_muex;
+
+	return 0;
+}
+
+/**
+ * extcon_alloc_groups() - alloc the groups for extcon device
+ * @edev:	extcon device
+ *
+ * Returns 0 if success or error number if fail.
+ */
+static int extcon_alloc_groups(struct extcon_dev *edev)
+{
+	int index;
+
+	if (!edev)
+		return -EINVAL;
+
+	if (!edev->max_supported)
+		return 0;
+
+	edev->extcon_dev_type.groups = kcalloc(edev->max_supported + 2,
+					  sizeof(*edev->extcon_dev_type.groups),
+					  GFP_KERNEL);
+	if (!edev->extcon_dev_type.groups)
+		return -ENOMEM;
+
+	edev->extcon_dev_type.name = dev_name(&edev->dev);
+	edev->extcon_dev_type.release = dummy_sysfs_dev_release;
+
+	for (index = 0; index < edev->max_supported; index++)
+		edev->extcon_dev_type.groups[index] = &edev->cables[index].attr_g;
+
+	if (edev->mutually_exclusive)
+		edev->extcon_dev_type.groups[index] = &edev->attr_g_muex;
+
+	edev->dev.type = &edev->extcon_dev_type;
+
+	return 0;
+}
+
+/**
+ * extcon_dev_register() - Register an new extcon device
+ * @edev:	the extcon device to be registered
+ *
+ * Among the members of edev struct, please set the "user initializing data"
+ * do not set the values of "internal data", which are initialized by
+ * this function.
+ *
+ * Note that before calling this funciton, have to allocate the memory
+ * of an extcon device by using the extcon_dev_allocate(). And the extcon
+ * dev should include the supported_cable information.
+ *
+ * Returns 0 if success or error number if fail.
+ */
+int extcon_dev_register(struct extcon_dev *edev)
+{
+	int ret, index;
+
+	ret = create_extcon_class();
+	if (ret < 0)
+		return ret;
+
+	if (!edev || !edev->supported_cable)
+		return -EINVAL;
+
+	for (index = 0; edev->supported_cable[index] != EXTCON_NONE; index++);
+
+	edev->max_supported = index;
+	if (index > SUPPORTED_CABLE_MAX) {
+		dev_err(&edev->dev,
+			"exceed the maximum number of supported cables\n");
+		return -EINVAL;
+	}
+
+	edev->dev.class = extcon_class;
+	edev->dev.release = extcon_dev_release;
+
+	edev->name = dev_name(edev->dev.parent);
+	if (IS_ERR_OR_NULL(edev->name)) {
+		dev_err(&edev->dev,
+			"extcon device name is null\n");
+		return -EINVAL;
+	}
+
+	ret = ida_alloc(&extcon_dev_ids, GFP_KERNEL);
+	if (ret < 0)
+		return ret;
+
+	edev->id = ret;
+
+	dev_set_name(&edev->dev, "extcon%d", edev->id);
+
+	ret = extcon_alloc_cables(edev);
+	if (ret < 0)
+		goto err_alloc_cables;
+
+	ret = extcon_alloc_muex(edev);
+	if (ret < 0)
+		goto err_alloc_muex;
+
+	ret = extcon_alloc_groups(edev);
+	if (ret < 0)
+		goto err_alloc_groups;
+
+	spin_lock_init(&edev->lock);
+	if (edev->max_supported) {
+		edev->nh = kcalloc(edev->max_supported, sizeof(*edev->nh),
+				GFP_KERNEL);
+		if (!edev->nh) {
+			ret = -ENOMEM;
+			goto err_alloc_nh;
+		}
+	}
+
+	for (index = 0; index < edev->max_supported; index++)
+		RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]);
+
+	RAW_INIT_NOTIFIER_HEAD(&edev->nh_all);
+
+	dev_set_drvdata(&edev->dev, edev);
+	edev->state = 0;
+
+	ret = device_register(&edev->dev);
+	if (ret) {
+		put_device(&edev->dev);
+		goto err_dev;
+	}
+
+	mutex_lock(&extcon_dev_list_lock);
+	list_add(&edev->entry, &extcon_dev_list);
+	mutex_unlock(&extcon_dev_list_lock);
+
+	return 0;
+
+err_dev:
+	if (edev->max_supported)
+		kfree(edev->nh);
+err_alloc_nh:
+	if (edev->max_supported)
+		kfree(edev->extcon_dev_type.groups);
+err_alloc_groups:
+	if (edev->max_supported && edev->mutually_exclusive) {
+		for (index = 0; edev->mutually_exclusive[index]; index++)
+			kfree(edev->d_attrs_muex[index].attr.name);
+		kfree(edev->d_attrs_muex);
+		kfree(edev->attrs_muex);
+	}
+err_alloc_muex:
+	for (index = 0; index < edev->max_supported; index++)
+		kfree(edev->cables[index].attr_g.name);
+	if (edev->max_supported)
+		kfree(edev->cables);
+err_alloc_cables:
+	ida_free(&extcon_dev_ids, edev->id);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(extcon_dev_register);
+
+/**
+ * extcon_dev_unregister() - Unregister the extcon device.
+ * @edev:	the extcon device to be unregistered.
+ *
+ * Note that this does not call kfree(edev) because edev was not allocated
+ * by this class.
+ */
+void extcon_dev_unregister(struct extcon_dev *edev)
+{
+	int index;
+
+	if (!edev)
+		return;
+
+	mutex_lock(&extcon_dev_list_lock);
+	list_del(&edev->entry);
+	mutex_unlock(&extcon_dev_list_lock);
+
+	if (!get_device(&edev->dev)) {
+		dev_err(&edev->dev, "Failed to unregister extcon_dev\n");
+		return;
+	}
+
+	ida_free(&extcon_dev_ids, edev->id);
+
+	device_unregister(&edev->dev);
+
+	if (edev->mutually_exclusive && edev->max_supported) {
+		for (index = 0; edev->mutually_exclusive[index];
+				index++)
+			kfree(edev->d_attrs_muex[index].attr.name);
+		kfree(edev->d_attrs_muex);
+		kfree(edev->attrs_muex);
+	}
+
+	for (index = 0; index < edev->max_supported; index++)
+		kfree(edev->cables[index].attr_g.name);
+
+	if (edev->max_supported) {
+		kfree(edev->extcon_dev_type.groups);
+		kfree(edev->cables);
+		kfree(edev->nh);
+	}
+
+	put_device(&edev->dev);
+}
+EXPORT_SYMBOL_GPL(extcon_dev_unregister);
+
+#ifdef CONFIG_OF
+
+/*
+ * extcon_find_edev_by_node - Find the extcon device from devicetree.
+ * @node	: OF node identifying edev
+ *
+ * Return the pointer of extcon device if success or ERR_PTR(err) if fail.
+ */
+struct extcon_dev *extcon_find_edev_by_node(struct device_node *node)
+{
+	struct extcon_dev *edev;
+
+	mutex_lock(&extcon_dev_list_lock);
+	list_for_each_entry(edev, &extcon_dev_list, entry)
+		if (edev->dev.parent && device_match_of_node(edev->dev.parent, node))
+			goto out;
+	edev = ERR_PTR(-EPROBE_DEFER);
+out:
+	mutex_unlock(&extcon_dev_list_lock);
+
+	return edev;
+}
+
+/*
+ * extcon_get_edev_by_phandle - Get the extcon device from devicetree.
+ * @dev		: the instance to the given device
+ * @index	: the index into list of extcon_dev
+ *
+ * Return the pointer of extcon device if success or ERR_PTR(err) if fail.
+ */
+struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
+{
+	struct device_node *node, *np = dev_of_node(dev);
+	struct extcon_dev *edev;
+
+	if (!np) {
+		dev_dbg(dev, "device does not have a device node entry\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	node = of_parse_phandle(np, "extcon", index);
+	if (!node) {
+		dev_dbg(dev, "failed to get phandle in %pOF node\n", np);
+		return ERR_PTR(-ENODEV);
+	}
+
+	edev = extcon_find_edev_by_node(node);
+	of_node_put(node);
+
+	return edev;
+}
+
+#else
+
+struct extcon_dev *extcon_find_edev_by_node(struct device_node *node)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
+struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
+#endif /* CONFIG_OF */
+
+EXPORT_SYMBOL_GPL(extcon_find_edev_by_node);
+EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
+
+/**
+ * extcon_get_edev_name() - Get the name of the extcon device.
+ * @edev:	the extcon device
+ */
+const char *extcon_get_edev_name(struct extcon_dev *edev)
+{
+	return !edev ? NULL : edev->name;
+}
+EXPORT_SYMBOL_GPL(extcon_get_edev_name);
+
+static int __init extcon_class_init(void)
+{
+	return create_extcon_class();
+}
+module_init(extcon_class_init);
+
+static void __exit extcon_class_exit(void)
+{
+	class_destroy(extcon_class);
+}
+module_exit(extcon_class_exit);
+
+MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
+MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
+MODULE_DESCRIPTION("External Connector (extcon) framework");
+MODULE_LICENSE("GPL v2");