Extcon: add MAX8997 extcon driver

This patch add extcon-max8997 driver to support the muic feature
of Maxim max8997 by using Extcon framework.

The extcon-max8997 driver is implemented based on 'drivers/misc/
max8997-muic.c' and then use Extcon interface instead of callback
function in struct max8997_muic_platform_data to notify cable state
of notifee which want to know always newly cable state when external
connector(e.g., USB, TA, JIG) is attached or detached.

v1
- Use Extcon interface to notify cable state of notifee instead of
 callback function when external connector is attached or detached.
- Bug fix of getting platform_data for irq_base value.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 546 insertions, 0 deletions

diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
index 85cecff36db3..29c5cf852efc 100644
--- a/drivers/extcon/Kconfig
+++ b/drivers/extcon/Kconfig
@@ -21,4 +21,12 @@ config EXTCON_GPIO
 	  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
index 2c46d4176d18..86020bdb6da0 100644
--- a/drivers/extcon/Makefile
+++ b/drivers/extcon/Makefile
@@ -4,3 +4,4 @@
 
 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..2b1aa04a27dd
--- /dev/null
+++ b/drivers/extcon/extcon-max8997.c
@@ -0,0 +1,537 @@
+/*
+ * 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);
+
+			for (i = i - 1; i >= 0; i--)
+				free_irq(muic_irq->irq, info);
+
+			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:
+	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");