1 files changed, 836 insertions, 0 deletions

diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c
new file mode 100644
index 000000000000..946a3188b2b7
--- /dev/null
+++ b/drivers/extcon/extcon-class.c
@@ -0,0 +1,836 @@
+/*
+ *  drivers/extcon/extcon_class.c
+ *
+ *  External connector (extcon) class driver
+ *
+ * Copyright (C) 2012 Samsung Electronics
+ * Author: Donggeun Kim <dg77.kim@samsung.com>
+ * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * based on android/drivers/switch/switch_class.c
+ * Copyright (C) 2008 Google, Inc.
+ * Author: Mike Lockwood <lockwood@android.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+*/
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/err.h>
+#include <linux/extcon.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+
+/*
+ * extcon_cable_name suggests the standard cable names for commonly used
+ * cable types.
+ *
+ * However, please do not use extcon_cable_name directly for extcon_dev
+ * struct's supported_cable pointer unless your device really supports
+ * every single port-type of the following cable names. Please choose cable
+ * names that are actually used in your extcon device.
+ */
+const char *extcon_cable_name[] = {
+	[EXTCON_USB]		= "USB",
+	[EXTCON_USB_HOST]	= "USB-Host",
+	[EXTCON_TA]		= "TA",
+	[EXTCON_FAST_CHARGER]	= "Fast-charger",
+	[EXTCON_SLOW_CHARGER]	= "Slow-charger",
+	[EXTCON_CHARGE_DOWNSTREAM]	= "Charge-downstream",
+	[EXTCON_HDMI]		= "HDMI",
+	[EXTCON_MHL]		= "MHL",
+	[EXTCON_DVI]		= "DVI",
+	[EXTCON_VGA]		= "VGA",
+	[EXTCON_DOCK]		= "Dock",
+	[EXTCON_LINE_IN]	= "Line-in",
+	[EXTCON_LINE_OUT]	= "Line-out",
+	[EXTCON_MIC_IN]		= "Microphone",
+	[EXTCON_HEADPHONE_OUT]	= "Headphone",
+	[EXTCON_SPDIF_IN]	= "SPDIF-in",
+	[EXTCON_SPDIF_OUT]	= "SPDIF-out",
+	[EXTCON_VIDEO_IN]	= "Video-in",
+	[EXTCON_VIDEO_OUT]	= "Video-out",
+	[EXTCON_MECHANICAL]	= "Mechanical",
+
+	NULL,
+};
+
+static struct class *extcon_class;
+#if defined(CONFIG_ANDROID)
+static struct class_compat *switch_class;
+#endif /* CONFIG_ANDROID */
+
+static LIST_HEAD(extcon_dev_list);
+static DEFINE_MUTEX(extcon_dev_list_lock);
+
+/**
+ * check_mutually_exclusive - Check if new_state violates mutually_exclusive
+ *			    condition.
+ * @edev:	the extcon device
+ * @new_state:	new cable attach status for @edev
+ *
+ * Returns 0 if nothing violates. Returns the index + 1 for the first
+ * violated condition.
+ */
+static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
+{
+	int i = 0;
+
+	if (!edev->mutually_exclusive)
+		return 0;
+
+	for (i = 0; edev->mutually_exclusive[i]; i++) {
+		int count = 0, j;
+		u32 correspondants = new_state & edev->mutually_exclusive[i];
+		u32 exp = 1;
+
+		for (j = 0; j < 32; j++) {
+			if (exp & correspondants)
+				count++;
+			if (count > 1)
+				return i + 1;
+			exp <<= 1;
+		}
+	}
+
+	return 0;
+}
+
+static ssize_t state_show(struct device *dev, struct device_attribute *attr,
+			  char *buf)
+{
+	int i, count = 0;
+	struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
+
+	if (edev->print_state) {
+		int ret = edev->print_state(edev, buf);
+
+		if (ret >= 0)
+			return ret;
+		/* Use default if failed */
+	}
+
+	if (edev->max_supported == 0)
+		return sprintf(buf, "%u\n", edev->state);
+
+	for (i = 0; i < SUPPORTED_CABLE_MAX; i++) {
+		if (!edev->supported_cable[i])
+			break;
+		count += sprintf(buf + count, "%s=%d\n",
+				 edev->supported_cable[i],
+				 !!(edev->state & (1 << i)));
+	}
+
+	return count;
+}
+
+int extcon_set_state(struct extcon_dev *edev, u32 state);
+static ssize_t state_store(struct device *dev, struct device_attribute *attr,
+			   const char *buf, size_t count)
+{
+	u32 state;
+	ssize_t ret = 0;
+	struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
+
+	ret = sscanf(buf, "0x%x", &state);
+	if (ret == 0)
+		ret = -EINVAL;
+	else
+		ret = extcon_set_state(edev, state);
+
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static ssize_t name_show(struct device *dev, struct device_attribute *attr,
+		char *buf)
+{
+	struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
+
+	/* Optional callback given by the user */
+	if (edev->print_name) {
+		int ret = edev->print_name(edev, buf);
+		if (ret >= 0)
+			return ret;
+	}
+
+	return sprintf(buf, "%s\n", dev_name(edev->dev));
+}
+
+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);
+
+	return sprintf(buf, "%s\n",
+		       cable->edev->supported_cable[cable->cable_index]);
+}
+
+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);
+
+	return sprintf(buf, "%d\n",
+		       extcon_get_cable_state_(cable->edev,
+					       cable->cable_index));
+}
+
+static ssize_t cable_state_store(struct device *dev,
+				 struct device_attribute *attr, const char *buf,
+				 size_t count)
+{
+	struct extcon_cable *cable = container_of(attr, struct extcon_cable,
+						  attr_state);
+	int ret, state;
+
+	ret = sscanf(buf, "%d", &state);
+	if (ret == 0)
+		ret = -EINVAL;
+	else
+		ret = extcon_set_cable_state_(cable->edev, cable->cable_index,
+					      state);
+
+	if (ret < 0)
+		return ret;
+	return count;
+}
+
+/**
+ * extcon_update_state() - Update the cable attach states of the extcon device
+ *			only for the masked bits.
+ * @edev:	the extcon device
+ * @mask:	the bit mask to designate updated bits.
+ * @state:	new cable attach status for @edev
+ *
+ * Changing the state sends uevent with environment variable containing
+ * the name of extcon device (envp[0]) and the state output (envp[1]).
+ * Tizen uses this format for extcon device to get events from ports.
+ * Android uses this format as well.
+ *
+ * Note that the notifier provides which bits are changed in the state
+ * variable with the val parameter (second) to the callback.
+ */
+int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
+{
+	char name_buf[120];
+	char state_buf[120];
+	char *prop_buf;
+	char *envp[3];
+	int env_offset = 0;
+	int length;
+	unsigned long flags;
+
+	spin_lock_irqsave(&edev->lock, flags);
+
+	if (edev->state != ((edev->state & ~mask) | (state & mask))) {
+		u32 old_state = edev->state;
+
+		if (check_mutually_exclusive(edev, (edev->state & ~mask) |
+						   (state & mask))) {
+			spin_unlock_irqrestore(&edev->lock, flags);
+			return -EPERM;
+		}
+
+		edev->state &= ~mask;
+		edev->state |= state & mask;
+
+		raw_notifier_call_chain(&edev->nh, old_state, edev);
+
+		/* This could be in interrupt handler */
+		prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
+		if (prop_buf) {
+			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);
+		} else {
+			/* 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);
+		}
+	} else {
+		/* No changes */
+		spin_unlock_irqrestore(&edev->lock, flags);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(extcon_update_state);
+
+/**
+ * extcon_set_state() - Set the cable attach states of the extcon device.
+ * @edev:	the extcon device
+ * @state:	new cable attach status for @edev
+ *
+ * Note that notifier provides which bits are changed in the state
+ * variable with the val parameter (second) to the callback.
+ */
+int extcon_set_state(struct extcon_dev *edev, u32 state)
+{
+	return extcon_update_state(edev, 0xffffffff, state);
+}
+EXPORT_SYMBOL_GPL(extcon_set_state);
+
+/**
+ * extcon_find_cable_index() - Get the cable index based on the cable name.
+ * @edev:	the extcon device that has the cable.
+ * @cable_name:	cable name to be searched.
+ *
+ * Note that accessing a cable state based on cable_index is faster than
+ * cable_name because using cable_name induces a loop with strncmp().
+ * Thus, when get/set_cable_state is repeatedly used, using cable_index
+ * is recommended.
+ */
+int extcon_find_cable_index(struct extcon_dev *edev, const char *cable_name)
+{
+	int i;
+
+	if (edev->supported_cable) {
+		for (i = 0; edev->supported_cable[i]; i++) {
+			if (!strncmp(edev->supported_cable[i],
+				cable_name, CABLE_NAME_MAX))
+				return i;
+		}
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(extcon_find_cable_index);
+
+/**
+ * extcon_get_cable_state_() - Get the status of a specific cable.
+ * @edev:	the extcon device that has the cable.
+ * @index:	cable index that can be retrieved by extcon_find_cable_index().
+ */
+int extcon_get_cable_state_(struct extcon_dev *edev, int index)
+{
+	if (index < 0 || (edev->max_supported && edev->max_supported <= index))
+		return -EINVAL;
+
+	return !!(edev->state & (1 << index));
+}
+EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
+
+/**
+ * extcon_get_cable_state() - Get the status of a specific cable.
+ * @edev:	the extcon device that has the cable.
+ * @cable_name:	cable name.
+ *
+ * Note that this is slower than extcon_get_cable_state_.
+ */
+int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)
+{
+	return extcon_get_cable_state_(edev, extcon_find_cable_index
+						(edev, cable_name));
+}
+EXPORT_SYMBOL_GPL(extcon_get_cable_state);
+
+/**
+ * extcon_get_cable_state_() - Set the status of a specific cable.
+ * @edev:	the extcon device that has the cable.
+ * @index:	cable index that can be retrieved by extcon_find_cable_index().
+ * @cable_state:	the new cable status. The default semantics is
+ *			true: attached / false: detached.
+ */
+int extcon_set_cable_state_(struct extcon_dev *edev,
+			int index, bool cable_state)
+{
+	u32 state;
+
+	if (index < 0 || (edev->max_supported && edev->max_supported <= index))
+		return -EINVAL;
+
+	state = cable_state ? (1 << index) : 0;
+	return extcon_update_state(edev, 1 << index, state);
+}
+EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
+
+/**
+ * extcon_get_cable_state() - Set the status of a specific cable.
+ * @edev:	the extcon device that has the cable.
+ * @cable_name:	cable name.
+ * @cable_state:	the new cable status. The default semantics is
+ *			true: attached / false: detached.
+ *
+ * Note that this is slower than extcon_set_cable_state_.
+ */
+int extcon_set_cable_state(struct extcon_dev *edev,
+			const char *cable_name, bool cable_state)
+{
+	return extcon_set_cable_state_(edev, extcon_find_cable_index
+					(edev, cable_name), cable_state);
+}
+EXPORT_SYMBOL_GPL(extcon_set_cable_state);
+
+/**
+ * extcon_get_extcon_dev() - Get the extcon device instance from the name
+ * @extcon_name:	The extcon name provided with extcon_dev_register()
+ */
+struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
+{
+	struct extcon_dev *sd;
+
+	mutex_lock(&extcon_dev_list_lock);
+	list_for_each_entry(sd, &extcon_dev_list, entry) {
+		if (!strcmp(sd->name, extcon_name))
+			goto out;
+	}
+	sd = NULL;
+out:
+	mutex_unlock(&extcon_dev_list_lock);
+	return sd;
+}
+EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
+
+static int _call_per_cable(struct notifier_block *nb, unsigned long val,
+			   void *ptr)
+{
+	struct extcon_specific_cable_nb *obj = container_of(nb,
+			struct extcon_specific_cable_nb, internal_nb);
+	struct extcon_dev *edev = ptr;
+
+	if ((val & (1 << obj->cable_index)) !=
+	    (edev->state & (1 << obj->cable_index))) {
+		bool cable_state = true;
+
+		obj->previous_value = val;
+
+		if (val & (1 << obj->cable_index))
+			cable_state = false;
+
+		return obj->user_nb->notifier_call(obj->user_nb,
+				cable_state, ptr);
+	}
+
+	return NOTIFY_OK;
+}
+
+/**
+ * extcon_register_interest() - Register a notifier for a state change of a
+ *			      specific cable, not an entier set of cables of a
+ *			      extcon device.
+ * @obj:	an empty extcon_specific_cable_nb object to be returned.
+ * @extcon_name:	the name of extcon device.
+ * @cable_name:		the target cable name.
+ * @nb:		the notifier block to get notified.
+ *
+ * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
+ * the struct for you.
+ *
+ * extcon_register_interest is a helper function for those who want to get
+ * notification for a single specific cable's status change. If a user wants
+ * to get notification for any changes of all cables of a extcon device,
+ * he/she should use the general extcon_register_notifier().
+ *
+ * Note that the second parameter given to the callback of nb (val) is
+ * "old_state", not the current state. The current state can be retrieved
+ * by looking at the third pameter (edev pointer)'s state value.
+ */
+int extcon_register_interest(struct extcon_specific_cable_nb *obj,
+			     const char *extcon_name, const char *cable_name,
+			     struct notifier_block *nb)
+{
+	if (!obj || !extcon_name || !cable_name || !nb)
+		return -EINVAL;
+
+	obj->edev = extcon_get_extcon_dev(extcon_name);
+	if (!obj->edev)
+		return -ENODEV;
+
+	obj->cable_index = extcon_find_cable_index(obj->edev, cable_name);
+	if (obj->cable_index < 0)
+		return -ENODEV;
+
+	obj->user_nb = nb;
+
+	obj->internal_nb.notifier_call = _call_per_cable;
+
+	return raw_notifier_chain_register(&obj->edev->nh, &obj->internal_nb);
+}
+
+/**
+ * extcon_unregister_interest() - Unregister the notifier registered by
+ *				extcon_register_interest().
+ * @obj:	the extcon_specific_cable_nb object returned by
+ *		extcon_register_interest().
+ */
+int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
+{
+	if (!obj)
+		return -EINVAL;
+
+	return raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb);
+}
+
+/**
+ * extcon_register_notifier() - Register a notifiee to get notified by
+ *			      any attach status changes from the extcon.
+ * @edev:	the extcon device.
+ * @nb:		a notifier block to be registered.
+ *
+ * Note that the second parameter given to the callback of nb (val) is
+ * "old_state", not the current state. The current state can be retrieved
+ * by looking at the third pameter (edev pointer)'s state value.
+ */
+int extcon_register_notifier(struct extcon_dev *edev,
+			struct notifier_block *nb)
+{
+	return raw_notifier_chain_register(&edev->nh, nb);
+}
+EXPORT_SYMBOL_GPL(extcon_register_notifier);
+
+/**
+ * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
+ * @edev:	the extcon device.
+ * @nb:		a registered notifier block to be unregistered.
+ */
+int extcon_unregister_notifier(struct extcon_dev *edev,
+			struct notifier_block *nb)
+{
+	return raw_notifier_chain_unregister(&edev->nh, nb);
+}
+EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
+
+static struct device_attribute extcon_attrs[] = {
+	__ATTR(state, S_IRUGO | S_IWUSR, state_show, state_store),
+	__ATTR_RO(name),
+	__ATTR_NULL,
+};
+
+static int create_extcon_class(void)
+{
+	if (!extcon_class) {
+		extcon_class = class_create(THIS_MODULE, "extcon");
+		if (IS_ERR(extcon_class))
+			return PTR_ERR(extcon_class);
+		extcon_class->dev_attrs = extcon_attrs;
+
+#if defined(CONFIG_ANDROID)
+		switch_class = class_compat_register("switch");
+		if (WARN(!switch_class, "cannot allocate"))
+			return -ENOMEM;
+#endif /* CONFIG_ANDROID */
+	}
+
+	return 0;
+}
+
+static void extcon_cleanup(struct extcon_dev *edev, bool skip)
+{
+	mutex_lock(&extcon_dev_list_lock);
+	list_del(&edev->entry);
+	mutex_unlock(&extcon_dev_list_lock);
+
+	if (!skip && get_device(edev->dev)) {
+		int index;
+
+		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);
+		}
+
+		device_unregister(edev->dev);
+		put_device(edev->dev);
+	}
+
+	kfree(edev->dev);
+}
+
+static void extcon_dev_release(struct device *dev)
+{
+	struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
+
+	extcon_cleanup(edev, true);
+}
+
+static const char *muex_name = "mutually_exclusive";
+static void dummy_sysfs_dev_release(struct device *dev)
+{
+}
+
+/**
+ * extcon_dev_register() - Register a new extcon device
+ * @edev	: the new extcon device (should be allocated before calling)
+ * @dev		: the parent device for this extcon device.
+ *
+ * Among the members of edev struct, please set the "user initializing data"
+ * in any case and set the "optional callbacks" if required. However, please
+ * do not set the values of "internal data", which are initialized by
+ * this function.
+ */
+int extcon_dev_register(struct extcon_dev *edev, struct device *dev)
+{
+	int ret, index = 0;
+
+	if (!extcon_class) {
+		ret = create_extcon_class();
+		if (ret < 0)
+			return ret;
+	}
+
+	if (edev->supported_cable) {
+		/* Get size of array */
+		for (index = 0; edev->supported_cable[index]; index++)
+			;
+		edev->max_supported = index;
+	} else {
+		edev->max_supported = 0;
+	}
+
+	if (index > SUPPORTED_CABLE_MAX) {
+		dev_err(edev->dev, "extcon: maximum number of supported cables exceeded.\n");
+		return -EINVAL;
+	}
+
+	edev->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
+	if (!edev->dev)
+		return -ENOMEM;
+	edev->dev->parent = dev;
+	edev->dev->class = extcon_class;
+	edev->dev->release = extcon_dev_release;
+
+	dev_set_name(edev->dev, edev->name ? edev->name : dev_name(dev));
+
+	if (edev->max_supported) {
+		char buf[10];
+		char *str;
+		struct extcon_cable *cable;
+
+		edev->cables = kzalloc(sizeof(struct extcon_cable) *
+				       edev->max_supported, GFP_KERNEL);
+		if (!edev->cables) {
+			ret = -ENOMEM;
+			goto err_sysfs_alloc;
+		}
+		for (index = 0; index < edev->max_supported; index++) {
+			cable = &edev->cables[index];
+
+			snprintf(buf, 10, "cable.%d", index);
+			str = kzalloc(sizeof(char) * (strlen(buf) + 1),
+				      GFP_KERNEL);
+			if (!str) {
+				for (index--; index >= 0; index--) {
+					cable = &edev->cables[index];
+					kfree(cable->attr_g.name);
+				}
+				ret = -ENOMEM;
+
+				goto err_alloc_cables;
+			}
+			strcpy(str, buf);
+
+			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 = 0644;
+			cable->attr_state.show = cable_state_show;
+			cable->attr_state.store = cable_state_store;
+		}
+	}
+
+	if (edev->max_supported && edev->mutually_exclusive) {
+		char buf[80];
+		char *name;
+
+		/* Count the size of mutually_exclusive array */
+		for (index = 0; edev->mutually_exclusive[index]; index++)
+			;
+
+		edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
+					   (index + 1), GFP_KERNEL);
+		if (!edev->attrs_muex) {
+			ret = -ENOMEM;
+			goto err_muex;
+		}
+
+		edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
+					     index, GFP_KERNEL);
+		if (!edev->d_attrs_muex) {
+			ret = -ENOMEM;
+			kfree(edev->attrs_muex);
+			goto err_muex;
+		}
+
+		for (index = 0; edev->mutually_exclusive[index]; index++) {
+			sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
+			name = kzalloc(sizeof(char) * (strlen(buf) + 1),
+				       GFP_KERNEL);
+			if (!name) {
+				for (index--; index >= 0; index--) {
+					kfree(edev->d_attrs_muex[index].attr.
+					      name);
+				}
+				kfree(edev->d_attrs_muex);
+				kfree(edev->attrs_muex);
+				ret = -ENOMEM;
+				goto err_muex;
+			}
+			strcpy(name, buf);
+			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;
+
+	}
+
+	if (edev->max_supported) {
+		edev->extcon_dev_type.groups =
+			kzalloc(sizeof(struct attribute_group *) *
+				(edev->max_supported + 2), GFP_KERNEL);
+		if (!edev->extcon_dev_type.groups) {
+			ret = -ENOMEM;
+			goto err_alloc_groups;
+		}
+
+		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;
+	}
+
+	ret = device_register(edev->dev);
+	if (ret) {
+		put_device(edev->dev);
+		goto err_dev;
+	}
+#if defined(CONFIG_ANDROID)
+	if (switch_class)
+		ret = class_compat_create_link(switch_class, edev->dev,
+					       NULL);
+#endif /* CONFIG_ANDROID */
+
+	spin_lock_init(&edev->lock);
+
+	RAW_INIT_NOTIFIER_HEAD(&edev->nh);
+
+	dev_set_drvdata(edev->dev, edev);
+	edev->state = 0;
+
+	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->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_muex:
+	for (index = 0; index < edev->max_supported; index++)
+		kfree(edev->cables[index].attr_g.name);
+err_alloc_cables:
+	if (edev->max_supported)
+		kfree(edev->cables);
+err_sysfs_alloc:
+	kfree(edev->dev);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(extcon_dev_register);
+
+/**
+ * extcon_dev_unregister() - Unregister the extcon device.
+ * @edev:	the extcon device instance 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)
+{
+	extcon_cleanup(edev, false);
+}
+EXPORT_SYMBOL_GPL(extcon_dev_unregister);
+
+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("Mike Lockwood <lockwood@android.com>");
+MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
+MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
+MODULE_DESCRIPTION("External connector (extcon) class driver");
+MODULE_LICENSE("GPL");