Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

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");