Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 1488 insertions, 0 deletions

diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c
new file mode 100644
index 000000000..98d85cc11
--- /dev/null
+++ b/drivers/extcon/extcon.c
@@ -0,0 +1,1488 @@
+// 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_obj(*edev);
+	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 = kzalloc_objs(*edev->cables, edev->max_supported);
+	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 = kzalloc_objs(*edev->attrs_muex, index + 1);
+	if (!edev->attrs_muex)
+		return -ENOMEM;
+
+	edev->d_attrs_muex = kzalloc_objs(*edev->d_attrs_muex, index);
+	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 = kzalloc_objs(*edev->extcon_dev_type.groups,
+						    edev->max_supported + 2);
+	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;
+
+	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 = kzalloc_objs(*edev->nh, edev->max_supported);
+		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);
+	dev_set_name(&edev->dev, "extcon%d", edev->id);
+	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;
+	}
+
+	device_unregister(&edev->dev);
+
+	ida_free(&extcon_dev_ids, edev->id);
+
+	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");