Merge tag 'driver-core-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg Kroah-Hartman:
 "Here's the driver core, and other driver subsystems, pull request for
  the 3.5-rc1 merge window.

  Outside of a few minor driver core changes, we ended up with the
  following different subsystem and core changes as well, due to
  interdependancies on the driver core:
   - hyperv driver updates
   - drivers/memory being created and some drivers moved into it
   - extcon driver subsystem created out of the old Android staging
     switch driver code
   - dynamic debug updates
   - printk rework, and /dev/kmsg changes

  All of this has been tested in the linux-next releases for a few weeks
  with no reported problems.

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

Fix up conflicts in drivers/extcon/extcon-max8997.c where git noticed
that a patch to the deleted drivers/misc/max8997-muic.c driver needs to
be applied to this one.

* tag 'driver-core-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (90 commits)
  uio_pdrv_genirq: get irq through platform resource if not set otherwise
  memory: tegra{20,30}-mc: Remove empty *_remove()
  printk() - isolate KERN_CONT users from ordinary complete lines
  sysfs: get rid of some lockdep false positives
  Drivers: hv: util: Properly handle version negotiations.
  Drivers: hv: Get rid of an unnecessary check in vmbus_prep_negotiate_resp()
  memory: tegra{20,30}-mc: Use dev_err_ratelimited()
  driver core: Add dev_*_ratelimited() family
  Driver Core: don't oops with unregistered driver in driver_find_device()
  printk() - restore prefix/timestamp printing for multi-newline strings
  printk: add stub for prepend_timestamp()
  ARM: tegra30: Make MC optional in Kconfig
  ARM: tegra20: Make MC optional in Kconfig
  ARM: tegra30: MC: Remove unnecessary BUG*()
  ARM: tegra20: MC: Remove unnecessary BUG*()
  printk: correctly align __log_buf
  ARM: tegra30: Add Tegra Memory Controller(MC) driver
  ARM: tegra20: Add Tegra Memory Controller(MC) driver
  printk() - restore timestamp printing at console output
  printk() - do not merge continuation lines of different threads
  ...

5 files changed, 1575 insertions, 0 deletions

diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
new file mode 100644
index 000000000000..29c5cf852efc
--- /dev/null
+++ b/drivers/extcon/Kconfig
@@ -0,0 +1,32 @@
+menuconfig EXTCON
+	tristate "External Connector Class (extcon) support"
+	help
+	  Say Y here to enable external connector class (extcon) support.
+	  This allows monitoring external connectors by userspace
+	  via sysfs and uevent and supports external connectors with
+	  multiple states; i.e., an extcon that may have multiple
+	  cables attached. For example, an external connector of a device
+	  may be used to connect an HDMI cable and a AC adaptor, and to
+	  host USB ports. Many of 30-pin connectors including PDMI are
+	  also good examples.
+
+if EXTCON
+
+comment "Extcon Device Drivers"
+
+config EXTCON_GPIO
+	tristate "GPIO extcon support"
+	depends on GENERIC_GPIO
+	help
+	  Say Y here to enable GPIO based extcon support. Note that GPIO
+	  extcon supports single state per extcon instance.
+
+config EXTCON_MAX8997
+	tristate "MAX8997 EXTCON Support"
+	depends on MFD_MAX8997
+	help
+	  If you say yes here you get support for the MUIC device of
+	  Maxim MAX8997 PMIC. The MAX8997 MUIC is a USB port accessory
+	  detector and switch.
+
+endif # MULTISTATE_SWITCH
diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
new file mode 100644
index 000000000000..86020bdb6da0
--- /dev/null
+++ b/drivers/extcon/Makefile
@@ -0,0 +1,7 @@
+#
+# Makefile for external connector class (extcon) devices
+#
+
+obj-$(CONFIG_EXTCON)		+= extcon_class.o
+obj-$(CONFIG_EXTCON_GPIO)	+= extcon_gpio.o
+obj-$(CONFIG_EXTCON_MAX8997)	+= extcon-max8997.o
diff --git a/drivers/extcon/extcon-max8997.c b/drivers/extcon/extcon-max8997.c
new file mode 100644
index 000000000000..23416e443765
--- /dev/null
+++ b/drivers/extcon/extcon-max8997.c
@@ -0,0 +1,535 @@
+/*
+ * extcon-max8997.c - MAX8997 extcon driver to support MAX8997 MUIC
+ *
+ *  Copyright (C) 2012 Samsung Electrnoics
+ *  Donggeun Kim <dg77.kim@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/kobject.h>
+#include <linux/mfd/max8997.h>
+#include <linux/mfd/max8997-private.h>
+#include <linux/extcon.h>
+
+#define	DEV_NAME			"max8997-muic"
+
+/* MAX8997-MUIC STATUS1 register */
+#define STATUS1_ADC_SHIFT		0
+#define STATUS1_ADCLOW_SHIFT		5
+#define STATUS1_ADCERR_SHIFT		6
+#define STATUS1_ADC_MASK		(0x1f << STATUS1_ADC_SHIFT)
+#define STATUS1_ADCLOW_MASK		(0x1 << STATUS1_ADCLOW_SHIFT)
+#define STATUS1_ADCERR_MASK		(0x1 << STATUS1_ADCERR_SHIFT)
+
+/* MAX8997-MUIC STATUS2 register */
+#define STATUS2_CHGTYP_SHIFT		0
+#define STATUS2_CHGDETRUN_SHIFT		3
+#define STATUS2_DCDTMR_SHIFT		4
+#define STATUS2_DBCHG_SHIFT		5
+#define STATUS2_VBVOLT_SHIFT		6
+#define STATUS2_CHGTYP_MASK		(0x7 << STATUS2_CHGTYP_SHIFT)
+#define STATUS2_CHGDETRUN_MASK		(0x1 << STATUS2_CHGDETRUN_SHIFT)
+#define STATUS2_DCDTMR_MASK		(0x1 << STATUS2_DCDTMR_SHIFT)
+#define STATUS2_DBCHG_MASK		(0x1 << STATUS2_DBCHG_SHIFT)
+#define STATUS2_VBVOLT_MASK		(0x1 << STATUS2_VBVOLT_SHIFT)
+
+/* MAX8997-MUIC STATUS3 register */
+#define STATUS3_OVP_SHIFT		2
+#define STATUS3_OVP_MASK		(0x1 << STATUS3_OVP_SHIFT)
+
+/* MAX8997-MUIC CONTROL1 register */
+#define COMN1SW_SHIFT			0
+#define COMP2SW_SHIFT			3
+#define COMN1SW_MASK			(0x7 << COMN1SW_SHIFT)
+#define COMP2SW_MASK			(0x7 << COMP2SW_SHIFT)
+#define SW_MASK				(COMP2SW_MASK | COMN1SW_MASK)
+
+#define MAX8997_SW_USB		((1 << COMP2SW_SHIFT) | (1 << COMN1SW_SHIFT))
+#define MAX8997_SW_AUDIO	((2 << COMP2SW_SHIFT) | (2 << COMN1SW_SHIFT))
+#define MAX8997_SW_UART		((3 << COMP2SW_SHIFT) | (3 << COMN1SW_SHIFT))
+#define MAX8997_SW_OPEN		((0 << COMP2SW_SHIFT) | (0 << COMN1SW_SHIFT))
+
+#define	MAX8997_ADC_GROUND		0x00
+#define	MAX8997_ADC_MHL			0x01
+#define	MAX8997_ADC_JIG_USB_1		0x18
+#define	MAX8997_ADC_JIG_USB_2		0x19
+#define	MAX8997_ADC_DESKDOCK		0x1a
+#define	MAX8997_ADC_JIG_UART		0x1c
+#define	MAX8997_ADC_CARDOCK		0x1d
+#define	MAX8997_ADC_OPEN		0x1f
+
+struct max8997_muic_irq {
+	unsigned int irq;
+	const char *name;
+};
+
+static struct max8997_muic_irq muic_irqs[] = {
+	{ MAX8997_MUICIRQ_ADCError, "muic-ADC_error" },
+	{ MAX8997_MUICIRQ_ADCLow, "muic-ADC_low" },
+	{ MAX8997_MUICIRQ_ADC, "muic-ADC" },
+	{ MAX8997_MUICIRQ_VBVolt, "muic-VB_voltage" },
+	{ MAX8997_MUICIRQ_DBChg, "muic-DB_charger" },
+	{ MAX8997_MUICIRQ_DCDTmr, "muic-DCD_timer" },
+	{ MAX8997_MUICIRQ_ChgDetRun, "muic-CDR_status" },
+	{ MAX8997_MUICIRQ_ChgTyp, "muic-charger_type" },
+	{ MAX8997_MUICIRQ_OVP, "muic-over_voltage" },
+};
+
+struct max8997_muic_info {
+	struct device *dev;
+	struct i2c_client *muic;
+	struct max8997_muic_platform_data *muic_pdata;
+
+	int irq;
+	struct work_struct irq_work;
+
+	enum max8997_muic_charger_type pre_charger_type;
+	int pre_adc;
+
+	struct mutex mutex;
+
+	struct extcon_dev	*edev;
+};
+
+const char *max8997_extcon_cable[] = {
+	[0] = "USB",
+	[1] = "USB-Host",
+	[2] = "TA",
+	[3] = "Fast-charger",
+	[4] = "Slow-charger",
+	[5] = "Charge-downstream",
+	[6] = "MHL",
+	[7] = "Dock-desk",
+	[7] = "Dock-card",
+	[8] = "JIG",
+
+	NULL,
+};
+
+static int max8997_muic_handle_usb(struct max8997_muic_info *info,
+			enum max8997_muic_usb_type usb_type, bool attached)
+{
+	int ret = 0;
+
+	if (usb_type == MAX8997_USB_HOST) {
+		/* switch to USB */
+		ret = max8997_update_reg(info->muic, MAX8997_MUIC_REG_CONTROL1,
+				attached ? MAX8997_SW_USB : MAX8997_SW_OPEN,
+				SW_MASK);
+		if (ret) {
+			dev_err(info->dev, "failed to update muic register\n");
+			goto out;
+		}
+	}
+
+	switch (usb_type) {
+	case MAX8997_USB_HOST:
+		extcon_set_cable_state(info->edev, "USB-Host", attached);
+		break;
+	case MAX8997_USB_DEVICE:
+		extcon_set_cable_state(info->edev, "USB", attached);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+out:
+	return ret;
+}
+
+static int max8997_muic_handle_dock(struct max8997_muic_info *info,
+			int adc, bool attached)
+{
+	int ret = 0;
+
+	/* switch to AUDIO */
+	ret = max8997_update_reg(info->muic, MAX8997_MUIC_REG_CONTROL1,
+				attached ? MAX8997_SW_AUDIO : MAX8997_SW_OPEN,
+				SW_MASK);
+	if (ret) {
+		dev_err(info->dev, "failed to update muic register\n");
+		goto out;
+	}
+
+	switch (adc) {
+	case MAX8997_ADC_DESKDOCK:
+		extcon_set_cable_state(info->edev, "Dock-desk", attached);
+		break;
+	case MAX8997_ADC_CARDOCK:
+		extcon_set_cable_state(info->edev, "Dock-card", attached);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+out:
+	return ret;
+}
+
+static int max8997_muic_handle_jig_uart(struct max8997_muic_info *info,
+			bool attached)
+{
+	int ret = 0;
+
+	/* switch to UART */
+	ret = max8997_update_reg(info->muic, MAX8997_MUIC_REG_CONTROL1,
+				attached ? MAX8997_SW_UART : MAX8997_SW_OPEN,
+				SW_MASK);
+	if (ret) {
+		dev_err(info->dev, "failed to update muic register\n");
+		goto out;
+	}
+
+	extcon_set_cable_state(info->edev, "JIG", attached);
+out:
+	return ret;
+}
+
+static int max8997_muic_handle_adc_detach(struct max8997_muic_info *info)
+{
+	int ret = 0;
+
+	switch (info->pre_adc) {
+	case MAX8997_ADC_GROUND:
+		ret = max8997_muic_handle_usb(info, MAX8997_USB_HOST, false);
+		break;
+	case MAX8997_ADC_MHL:
+		extcon_set_cable_state(info->edev, "MHL", false);
+		break;
+	case MAX8997_ADC_JIG_USB_1:
+	case MAX8997_ADC_JIG_USB_2:
+		ret = max8997_muic_handle_usb(info, MAX8997_USB_DEVICE, false);
+		break;
+	case MAX8997_ADC_DESKDOCK:
+	case MAX8997_ADC_CARDOCK:
+		ret = max8997_muic_handle_dock(info, info->pre_adc, false);
+		break;
+	case MAX8997_ADC_JIG_UART:
+		ret = max8997_muic_handle_jig_uart(info, false);
+		break;
+	default:
+		break;
+	}
+
+	return ret;
+}
+
+static int max8997_muic_handle_adc(struct max8997_muic_info *info, int adc)
+{
+	int ret = 0;
+
+	switch (adc) {
+	case MAX8997_ADC_GROUND:
+		ret = max8997_muic_handle_usb(info, MAX8997_USB_HOST, true);
+		break;
+	case MAX8997_ADC_MHL:
+		extcon_set_cable_state(info->edev, "MHL", true);
+		break;
+	case MAX8997_ADC_JIG_USB_1:
+	case MAX8997_ADC_JIG_USB_2:
+		ret = max8997_muic_handle_usb(info, MAX8997_USB_DEVICE, true);
+		break;
+	case MAX8997_ADC_DESKDOCK:
+	case MAX8997_ADC_CARDOCK:
+		ret = max8997_muic_handle_dock(info, adc, true);
+		break;
+	case MAX8997_ADC_JIG_UART:
+		ret = max8997_muic_handle_jig_uart(info, true);
+		break;
+	case MAX8997_ADC_OPEN:
+		ret = max8997_muic_handle_adc_detach(info);
+		break;
+	default:
+		ret = -EINVAL;
+		goto out;
+	}
+
+	info->pre_adc = adc;
+out:
+	return ret;
+}
+
+static int max8997_muic_handle_charger_type_detach(
+				struct max8997_muic_info *info)
+{
+	int ret = 0;
+
+	switch (info->pre_charger_type) {
+	case MAX8997_CHARGER_TYPE_USB:
+		extcon_set_cable_state(info->edev, "USB", false);
+		break;
+	case MAX8997_CHARGER_TYPE_DOWNSTREAM_PORT:
+		extcon_set_cable_state(info->edev, "Charge-downstream", false);
+		break;
+	case MAX8997_CHARGER_TYPE_DEDICATED_CHG:
+		extcon_set_cable_state(info->edev, "TA", false);
+		break;
+	case MAX8997_CHARGER_TYPE_500MA:
+		extcon_set_cable_state(info->edev, "Slow-charger", false);
+		break;
+	case MAX8997_CHARGER_TYPE_1A:
+		extcon_set_cable_state(info->edev, "Fast-charger", false);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+static int max8997_muic_handle_charger_type(struct max8997_muic_info *info,
+				enum max8997_muic_charger_type charger_type)
+{
+	u8 adc;
+	int ret;
+
+	ret = max8997_read_reg(info->muic, MAX8997_MUIC_REG_STATUS1, &adc);
+	if (ret) {
+		dev_err(info->dev, "failed to read muic register\n");
+		goto out;
+	}
+
+	switch (charger_type) {
+	case MAX8997_CHARGER_TYPE_NONE:
+		ret = max8997_muic_handle_charger_type_detach(info);
+		break;
+	case MAX8997_CHARGER_TYPE_USB:
+		if ((adc & STATUS1_ADC_MASK) == MAX8997_ADC_OPEN) {
+			max8997_muic_handle_usb(info,
+					MAX8997_USB_DEVICE, true);
+		}
+		break;
+	case MAX8997_CHARGER_TYPE_DOWNSTREAM_PORT:
+		extcon_set_cable_state(info->edev, "Charge-downstream", true);
+		break;
+	case MAX8997_CHARGER_TYPE_DEDICATED_CHG:
+		extcon_set_cable_state(info->edev, "TA", true);
+		break;
+	case MAX8997_CHARGER_TYPE_500MA:
+		extcon_set_cable_state(info->edev, "Slow-charger", true);
+		break;
+	case MAX8997_CHARGER_TYPE_1A:
+		extcon_set_cable_state(info->edev, "Fast-charger", true);
+		break;
+	default:
+		ret = -EINVAL;
+		goto out;
+	}
+
+	info->pre_charger_type = charger_type;
+out:
+	return ret;
+}
+
+static void max8997_muic_irq_work(struct work_struct *work)
+{
+	struct max8997_muic_info *info = container_of(work,
+			struct max8997_muic_info, irq_work);
+	struct max8997_dev *max8997 = i2c_get_clientdata(info->muic);
+	u8 status[2];
+	u8 adc, chg_type;
+
+	int irq_type = info->irq - max8997->irq_base;
+	int ret;
+
+	mutex_lock(&info->mutex);
+
+	ret = max8997_bulk_read(info->muic, MAX8997_MUIC_REG_STATUS1,
+				2, status);
+	if (ret) {
+		dev_err(info->dev, "failed to read muic register\n");
+		mutex_unlock(&info->mutex);
+		return;
+	}
+
+	dev_dbg(info->dev, "%s: STATUS1:0x%x, 2:0x%x\n", __func__,
+			status[0], status[1]);
+
+	switch (irq_type) {
+	case MAX8997_MUICIRQ_ADC:
+		adc = status[0] & STATUS1_ADC_MASK;
+		adc >>= STATUS1_ADC_SHIFT;
+
+		max8997_muic_handle_adc(info, adc);
+		break;
+	case MAX8997_MUICIRQ_ChgTyp:
+		chg_type = status[1] & STATUS2_CHGTYP_MASK;
+		chg_type >>= STATUS2_CHGTYP_SHIFT;
+
+		max8997_muic_handle_charger_type(info, chg_type);
+		break;
+	default:
+		dev_info(info->dev, "misc interrupt: irq %d occurred\n",
+				irq_type);
+		break;
+	}
+
+	mutex_unlock(&info->mutex);
+
+	return;
+}
+
+static irqreturn_t max8997_muic_irq_handler(int irq, void *data)
+{
+	struct max8997_muic_info *info = data;
+
+	dev_dbg(info->dev, "irq:%d\n", irq);
+	info->irq = irq;
+
+	schedule_work(&info->irq_work);
+
+	return IRQ_HANDLED;
+}
+
+static void max8997_muic_detect_dev(struct max8997_muic_info *info)
+{
+	int ret;
+	u8 status[2], adc, chg_type;
+
+	ret = max8997_bulk_read(info->muic, MAX8997_MUIC_REG_STATUS1,
+				2, status);
+	if (ret) {
+		dev_err(info->dev, "failed to read muic register\n");
+		return;
+	}
+
+	dev_info(info->dev, "STATUS1:0x%x, STATUS2:0x%x\n",
+			status[0], status[1]);
+
+	adc = status[0] & STATUS1_ADC_MASK;
+	adc >>= STATUS1_ADC_SHIFT;
+
+	chg_type = status[1] & STATUS2_CHGTYP_MASK;
+	chg_type >>= STATUS2_CHGTYP_SHIFT;
+
+	max8997_muic_handle_adc(info, adc);
+	max8997_muic_handle_charger_type(info, chg_type);
+}
+
+static int __devinit max8997_muic_probe(struct platform_device *pdev)
+{
+	struct max8997_dev *max8997 = dev_get_drvdata(pdev->dev.parent);
+	struct max8997_platform_data *pdata = dev_get_platdata(max8997->dev);
+	struct max8997_muic_info *info;
+	int ret, i;
+
+	info = kzalloc(sizeof(struct max8997_muic_info), GFP_KERNEL);
+	if (!info) {
+		dev_err(&pdev->dev, "failed to allocate memory\n");
+		ret = -ENOMEM;
+		goto err_kfree;
+	}
+
+	info->dev = &pdev->dev;
+	info->muic = max8997->muic;
+
+	platform_set_drvdata(pdev, info);
+	mutex_init(&info->mutex);
+
+	INIT_WORK(&info->irq_work, max8997_muic_irq_work);
+
+	for (i = 0; i < ARRAY_SIZE(muic_irqs); i++) {
+		struct max8997_muic_irq *muic_irq = &muic_irqs[i];
+
+		ret = request_threaded_irq(pdata->irq_base + muic_irq->irq,
+				NULL, max8997_muic_irq_handler,
+				0, muic_irq->name,
+				info);
+		if (ret) {
+			dev_err(&pdev->dev,
+				"failed: irq request (IRQ: %d,"
+				" error :%d)\n",
+				muic_irq->irq, ret);
+			goto err_irq;
+		}
+	}
+
+	/* External connector */
+	info->edev = kzalloc(sizeof(struct extcon_dev), GFP_KERNEL);
+	if (!info->edev) {
+		dev_err(&pdev->dev, "failed to allocate memory for extcon\n");
+		ret = -ENOMEM;
+		goto err_irq;
+	}
+	info->edev->name = DEV_NAME;
+	info->edev->supported_cable = max8997_extcon_cable;
+	ret = extcon_dev_register(info->edev, NULL);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register extcon device\n");
+		goto err_extcon;
+	}
+
+	/* Initialize registers according to platform data */
+	if (pdata->muic_pdata) {
+		struct max8997_muic_platform_data *mdata = info->muic_pdata;
+
+		for (i = 0; i < mdata->num_init_data; i++) {
+			max8997_write_reg(info->muic, mdata->init_data[i].addr,
+					mdata->init_data[i].data);
+		}
+	}
+
+	/* Initial device detection */
+	max8997_muic_detect_dev(info);
+
+	return ret;
+
+err_extcon:
+	kfree(info->edev);
+err_irq:
+	while (--i >= 0)
+		free_irq(pdata->irq_base + muic_irqs[i].irq, info);
+	kfree(info);
+err_kfree:
+	return ret;
+}
+
+static int __devexit max8997_muic_remove(struct platform_device *pdev)
+{
+	struct max8997_muic_info *info = platform_get_drvdata(pdev);
+	struct max8997_dev *max8997 = i2c_get_clientdata(info->muic);
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(muic_irqs); i++)
+		free_irq(max8997->irq_base + muic_irqs[i].irq, info);
+	cancel_work_sync(&info->irq_work);
+
+	extcon_dev_unregister(info->edev);
+
+	kfree(info);
+
+	return 0;
+}
+
+static struct platform_driver max8997_muic_driver = {
+	.driver		= {
+		.name	= DEV_NAME,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= max8997_muic_probe,
+	.remove		= __devexit_p(max8997_muic_remove),
+};
+
+module_platform_driver(max8997_muic_driver);
+
+MODULE_DESCRIPTION("Maxim MAX8997 Extcon driver");
+MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/extcon/extcon_class.c b/drivers/extcon/extcon_class.c
new file mode 100644
index 000000000000..f598a700ec15
--- /dev/null
+++ b/drivers/extcon/extcon_class.c
@@ -0,0 +1,832 @@
+/*
+ *  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>
+
+/*
+ * 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,
+};
+
+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 a 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 notifee 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 notifee 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;
+
+			cable->attr_name.attr.name = "name";
+			cable->attr_name.attr.mode = 0444;
+			cable->attr_name.show = cable_name_show;
+
+			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);
+			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,
+					       dev);
+#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 unregitered.
+ *
+ * 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");
diff --git a/drivers/extcon/extcon_gpio.c b/drivers/extcon/extcon_gpio.c
new file mode 100644
index 000000000000..fe7a07b47336
--- /dev/null
+++ b/drivers/extcon/extcon_gpio.c
@@ -0,0 +1,169 @@
+/*
+ *  drivers/extcon/extcon_gpio.c
+ *
+ *  Single-state GPIO extcon driver based on extcon class
+ *
+ * Copyright (C) 2008 Google, Inc.
+ * Author: Mike Lockwood <lockwood@android.com>
+ *
+ * Modified by MyungJoo Ham <myungjoo.ham@samsung.com> to support extcon
+ * (originally switch class is supported)
+ *
+ * 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/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/extcon.h>
+#include <linux/workqueue.h>
+#include <linux/gpio.h>
+#include <linux/extcon.h>
+#include <linux/extcon/extcon_gpio.h>
+
+struct gpio_extcon_data {
+	struct extcon_dev edev;
+	unsigned gpio;
+	const char *state_on;
+	const char *state_off;
+	int irq;
+	struct delayed_work work;
+	unsigned long debounce_jiffies;
+};
+
+static void gpio_extcon_work(struct work_struct *work)
+{
+	int state;
+	struct gpio_extcon_data	*data =
+		container_of(to_delayed_work(work), struct gpio_extcon_data,
+			     work);
+
+	state = gpio_get_value(data->gpio);
+	extcon_set_state(&data->edev, state);
+}
+
+static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
+{
+	struct gpio_extcon_data *extcon_data = dev_id;
+
+	schedule_delayed_work(&extcon_data->work,
+			      extcon_data->debounce_jiffies);
+	return IRQ_HANDLED;
+}
+
+static ssize_t extcon_gpio_print_state(struct extcon_dev *edev, char *buf)
+{
+	struct gpio_extcon_data	*extcon_data =
+		container_of(edev, struct gpio_extcon_data, edev);
+	const char *state;
+	if (extcon_get_state(edev))
+		state = extcon_data->state_on;
+	else
+		state = extcon_data->state_off;
+
+	if (state)
+		return sprintf(buf, "%s\n", state);
+	return -EINVAL;
+}
+
+static int __devinit gpio_extcon_probe(struct platform_device *pdev)
+{
+	struct gpio_extcon_platform_data *pdata = pdev->dev.platform_data;
+	struct gpio_extcon_data *extcon_data;
+	int ret = 0;
+
+	if (!pdata)
+		return -EBUSY;
+	if (!pdata->irq_flags) {
+		dev_err(&pdev->dev, "IRQ flag is not specified.\n");
+		return -EINVAL;
+	}
+
+	extcon_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_extcon_data),
+				   GFP_KERNEL);
+	if (!extcon_data)
+		return -ENOMEM;
+
+	extcon_data->edev.name = pdata->name;
+	extcon_data->gpio = pdata->gpio;
+	extcon_data->state_on = pdata->state_on;
+	extcon_data->state_off = pdata->state_off;
+	if (pdata->state_on && pdata->state_off)
+		extcon_data->edev.print_state = extcon_gpio_print_state;
+	extcon_data->debounce_jiffies = msecs_to_jiffies(pdata->debounce);
+
+	ret = extcon_dev_register(&extcon_data->edev, &pdev->dev);
+	if (ret < 0)
+		goto err_extcon_dev_register;
+
+	ret = gpio_request_one(extcon_data->gpio, GPIOF_DIR_IN, pdev->name);
+	if (ret < 0)
+		goto err_request_gpio;
+
+	INIT_DELAYED_WORK(&extcon_data->work, gpio_extcon_work);
+
+	extcon_data->irq = gpio_to_irq(extcon_data->gpio);
+	if (extcon_data->irq < 0) {
+		ret = extcon_data->irq;
+		goto err_detect_irq_num_failed;
+	}
+
+	ret = request_any_context_irq(extcon_data->irq, gpio_irq_handler,
+				      pdata->irq_flags, pdev->name,
+				      extcon_data);
+	if (ret < 0)
+		goto err_request_irq;
+
+	/* Perform initial detection */
+	gpio_extcon_work(&extcon_data->work.work);
+
+	return 0;
+
+err_request_irq:
+err_detect_irq_num_failed:
+	gpio_free(extcon_data->gpio);
+err_request_gpio:
+	extcon_dev_unregister(&extcon_data->edev);
+err_extcon_dev_register:
+	devm_kfree(&pdev->dev, extcon_data);
+
+	return ret;
+}
+
+static int __devexit gpio_extcon_remove(struct platform_device *pdev)
+{
+	struct gpio_extcon_data *extcon_data = platform_get_drvdata(pdev);
+
+	cancel_delayed_work_sync(&extcon_data->work);
+	gpio_free(extcon_data->gpio);
+	extcon_dev_unregister(&extcon_data->edev);
+	devm_kfree(&pdev->dev, extcon_data);
+
+	return 0;
+}
+
+static struct platform_driver gpio_extcon_driver = {
+	.probe		= gpio_extcon_probe,
+	.remove		= __devexit_p(gpio_extcon_remove),
+	.driver		= {
+		.name	= "extcon-gpio",
+		.owner	= THIS_MODULE,
+	},
+};
+
+module_platform_driver(gpio_extcon_driver);
+
+MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
+MODULE_DESCRIPTION("GPIO extcon driver");
+MODULE_LICENSE("GPL");