/*
 *  da9155_charger.c
 *  Samsung da9155 Charger Driver
 *
 *  Copyright (C) 2015 Samsung Electronics
 *
 * 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/battery/charger/da9155_charger.h>
#include <linux/of.h>
#include <linux/of_gpio.h>

#define DEBUG

#define ENABLE 1
#define DISABLE 0

static enum power_supply_property da9155_charger_props[] = {
	POWER_SUPPLY_PROP_HEALTH,				/* status */
	POWER_SUPPLY_PROP_ONLINE,				/* buck enable/disable */
	POWER_SUPPLY_PROP_CURRENT_MAX,			/* input current */
	POWER_SUPPLY_PROP_CURRENT_NOW,			/* charge current */
};

static int da9155_read_reg(struct i2c_client *client, u8 reg, u8 *dest)
{
	struct da9155_charger_data *charger = i2c_get_clientdata(client);
	int ret = 0;

	mutex_lock(&charger->io_lock);
	ret = i2c_smbus_read_byte_data(client, reg);
	mutex_unlock(&charger->io_lock);

	if (ret < 0) {
		pr_err("%s: can't read reg(0x%x), ret(%d)\n", __func__, reg, ret);
		return ret;
	}

	reg &= 0xFF;
	*dest = ret;

	return 0;
}

static int da9155_write_reg(struct i2c_client *client, u8 reg, u8 data)
{
	struct da9155_charger_data *charger = i2c_get_clientdata(client);
	int ret = 0;

	mutex_lock(&charger->io_lock);
	ret = i2c_smbus_write_byte_data(client, reg, data);
	mutex_unlock(&charger->io_lock);

	if (ret < 0)
		pr_err("%s: can't write reg(0x%x), ret(%d)\n", __func__, reg, ret);

	return ret;
}

static int da9155_update_reg(struct i2c_client *client, u8 reg, u8 val, u8 mask)
{
	struct da9155_charger_data *charger = i2c_get_clientdata(client);
	int ret = 0;

	mutex_lock(&charger->io_lock);
	ret = i2c_smbus_read_byte_data(client, reg);

	if (ret < 0)
		pr_err("%s: can't update reg(0x%x), ret(%d)\n", __func__, reg, ret);
	else {
		u8 old_val = ret & 0xFF;
		u8 new_val = (val & mask) | (old_val & (~mask));
		ret = i2c_smbus_write_byte_data(client, reg, new_val);
	}
	mutex_unlock(&charger->io_lock);

	return ret;
}

static void da9155_charger_test_read(struct da9155_charger_data *charger)
{
	u8 data = 0;
	u32 addr = 0;
	char str[1024]={0,};
	for (addr = 0x01; addr <= 0x13; addr++) {
		da9155_read_reg(charger->i2c, addr, &data);
		sprintf(str + strlen(str), "[0x%02x]0x%02x, ", addr, data);
	}
	pr_info("DA9155 : %s\n", str);
}

static int da9155_get_charger_state(struct da9155_charger_data *charger)
{
	u8 reg_data;

	da9155_read_reg(charger->i2c, DA9155_STATUS_B, &reg_data);
	if (reg_data & DA9155_MODE_MASK)
		return POWER_SUPPLY_STATUS_CHARGING;
	return POWER_SUPPLY_STATUS_NOT_CHARGING;
}

static int da9155_get_charger_health(struct da9155_charger_data *charger)
{
	u8 reg_data;

	da9155_charger_test_read(charger);

	da9155_read_reg(charger->i2c, DA9155_STATUS_A, &reg_data);
	if (reg_data & DA9155_S_VIN_UV_MASK) {
		pr_info("%s: VIN undervoltage\n", __func__);
		return POWER_SUPPLY_HEALTH_UNDERVOLTAGE;
	} else if (reg_data & DA9155_S_VIN_DROP_MASK) {
		pr_info("%s: VIN DROP\n", __func__);
		return POWER_SUPPLY_HEALTH_UNDERVOLTAGE;
	} else if (reg_data & DA9155_S_VIN_OV_MASK) {
		pr_info("%s: VIN overvoltage\n", __func__);
		return POWER_SUPPLY_HEALTH_OVERVOLTAGE;
	} else
		return POWER_SUPPLY_HEALTH_GOOD;
}

#if 0
static int da9155_get_input_current(struct da9155_charger_data *charger)
{
	u8 reg_data;
	int input_current;

	da9155_read_reg(charger->i2c, DA9155_BUCK_ILIM, &reg_data);
	input_current = reg_data * 100 + 3000;

	return input_current;
}
#endif

static int da9155_get_charge_current(struct da9155_charger_data *charger)
{
	u8 reg_data;
	int charge_current;

	da9155_read_reg(charger->i2c, DA9155_BUCK_IOUT, &reg_data);
	charge_current = reg_data * 10 + 250;

	return charge_current;
}

static void da9155_set_charger_state(struct da9155_charger_data *charger,
	int enable)
{
	pr_info("%s: BUCK_EN(%s)\n", enable > 0 ? "ENABLE" : "DISABLE", __func__);

	if (enable)
		da9155_update_reg(charger->i2c, DA9155_BUCK_CONT, DA9155_BUCK_EN_MASK, DA9155_BUCK_EN_MASK);
	else
		da9155_update_reg(charger->i2c, DA9155_BUCK_CONT, 0, DA9155_BUCK_EN_MASK);
}

#if 0
static void da9155_set_input_current(struct da9155_charger_data *charger,
	int input_current)
{
	u8 reg_data;

	reg_data = (input_current - 3000) / 100;

	da9155_update_reg(charger->i2c, DA9155_BUCK_ILIM, reg_data, DA9155_BUCK_ILIM_MASK);
	pr_info("%s: input_current(%d)\n", __func__, input_current);
}
#endif

static void da9155_set_charge_current(struct da9155_charger_data *charger,
	int charge_current)
{
	u8 reg_data;

	if (!charge_current) {
		reg_data = 0x00;
	} else {
		charge_current = (charge_current > 2500) ? 2500 : charge_current;
		reg_data = (charge_current - 250) / 10;
	}

	da9155_update_reg(charger->i2c, DA9155_BUCK_IOUT, reg_data, DA9155_BUCK_IOUT_MASK);
	pr_info("%s: charge_current(%d)\n", __func__, charge_current);
}

static void da9155_charger_initialize(struct da9155_charger_data *charger)
{
	pr_info("%s: \n", __func__);

	/* clear event reg */
	da9155_update_reg(charger->i2c, DA9155_EVENT_A, 0xFF, 0xFF);
	da9155_update_reg(charger->i2c, DA9155_EVENT_B, 0xFF, 0xFF);

	/* unmasked: E_VIN_UV, E_VIN_DROP, E_VIN_OV	*/
	da9155_update_reg(charger->i2c, DA9155_MASK_A,
		DA9155_M_VIN_UV_MASK | DA9155_M_VIN_DROP_MASK | DA9155_M_VIN_OV_MASK,
		DA9155_M_VIN_UV_MASK | DA9155_M_VIN_DROP_MASK | DA9155_M_VIN_OV_MASK);

	/* EN_BUCK: DISABLE, BUCK_ILIMIT: 5000mA */
	da9155_update_reg(charger->i2c, DA9155_BUCK_CONT, 0, DA9155_BUCK_EN_MASK);
	da9155_update_reg(charger->i2c, DA9155_BUCK_ILIM, 0x14, DA9155_BUCK_ILIM_MASK);

	/* VBAT_OV: MAX(5.175V) */
	da9155_update_reg(charger->i2c, DA9155_CONTROL_C, DA9155_VBAT_OV_MASK, DA9155_VBAT_OV_MASK);

	/* Juntion temmperature 145C */
	da9155_update_reg(charger->i2c, DA9155_CONTROL_E, DA9155_TJUNC_WARN_MASK, DA9155_TJUNC_WARN_MASK);
}

static irqreturn_t da9155_irq_handler(int irq, void *data)
{
	struct da9155_charger_data *charger = data;
	u8 reg_data_a, reg_data_b;

	pr_info("%s: \n", __func__);

	if (!da9155_read_reg(charger->i2c, DA9155_EVENT_A, &reg_data_a) &&
		!da9155_read_reg(charger->i2c, DA9155_EVENT_B, &reg_data_b)) {

		pr_info("%s: EVENT_A(0x%x), EVENT_B(0x%x)\n",
			__func__, reg_data_a, reg_data_b);

		/* clear event reg */
		da9155_update_reg(charger->i2c, DA9155_EVENT_A, 0xFF, 0xFF);
		da9155_update_reg(charger->i2c, DA9155_EVENT_B, 0xFF, 0xFF);
	}

	return IRQ_HANDLED;
}

static int da9155_chg_get_property(struct power_supply *psy,
	enum power_supply_property psp, union power_supply_propval *val)
{
	struct da9155_charger_data *charger =
		container_of(psy, struct da9155_charger_data, psy_chg);

	if (charger->cable_type == POWER_SUPPLY_TYPE_BATTERY) {
		pr_info("%s: skip get_property(psp type = %d)\n", __func__, psp);
		return -EINVAL;
	}

	switch (psp) {
	case POWER_SUPPLY_PROP_HEALTH:
		val->intval = da9155_get_charger_health(charger);
		break;
	case POWER_SUPPLY_PROP_ONLINE:
		val->intval = da9155_get_charger_state(charger);
		break;
	case POWER_SUPPLY_PROP_CURRENT_NOW:
		val->intval = da9155_get_charge_current(charger);
		break;
	case POWER_SUPPLY_PROP_CURRENT_MAX:
		return -ENODATA;
	default:
		return -EINVAL;
	}

	return 0;
}

static int da9155_chg_set_property(struct power_supply *psy,
	enum power_supply_property psp, const union power_supply_propval *val)
{
	struct da9155_charger_data *charger =
		container_of(psy, struct da9155_charger_data, psy_chg);

	switch (psp) {
	case POWER_SUPPLY_PROP_CHARGING_ENABLED:
		charger->is_charging =
			(val->intval == SEC_BAT_CHG_MODE_CHARGING) ? ENABLE : DISABLE;
		da9155_set_charger_state(charger, charger->is_charging);
		if (charger->is_charging == DISABLE)
			da9155_set_charge_current(charger, 0);
		break;
	case POWER_SUPPLY_PROP_CURRENT_NOW:
		charger->charging_current = val->intval;
		da9155_set_charge_current(charger, charger->charging_current);
		break;
	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
		charger->siop_level = val->intval;
		break;
	case POWER_SUPPLY_PROP_ONLINE:
		charger->cable_type = val->intval;
		if (val->intval != POWER_SUPPLY_TYPE_BATTERY) {
			da9155_charger_initialize(charger);
		}
		break;
	case POWER_SUPPLY_PROP_STATUS:
	case POWER_SUPPLY_PROP_CURRENT_FULL:
	case POWER_SUPPLY_PROP_VOLTAGE_MAX:
		break;
	case POWER_SUPPLY_PROP_CURRENT_MAX:
	case POWER_SUPPLY_PROP_HEALTH:
		return -ENODATA;
	default:
		return -EINVAL;
	}

	return 0;
}

static int da9155_charger_parse_dt(struct device *dev,
	sec_charger_platform_data_t *pdata)
{
	struct device_node *np = of_find_node_by_name(NULL, "da9155-charger");
	int ret = 0;

	if (!np) {
		pr_err("%s: np is NULL\n", __func__);
		return -1;
	} else {
		ret = of_get_named_gpio_flags(np, "da9155-charger,irq-gpio",
			0, NULL);
		if (ret < 0) {
			pr_err("%s: da9155-charger,irq-gpio is empty\n", __func__);
			pdata->irq_gpio = 0;
		} else {
			pdata->irq_gpio = ret;
			pr_info("%s: irq-gpio = %d\n", __func__, pdata->irq_gpio);
		}
	}

	np = of_find_node_by_name(NULL, "battery");
	if (!np) {
		pr_err("%s np is NULL\n", __func__);
		return -1;
	}

	return 0;
}

static int da9155_pinctrl_select(struct da9155_charger_data *charger, bool on) {
	struct pinctrl_state *pins_i2c_state;

	pins_i2c_state = on ? charger->i2c_gpio_state_active
			    : charger->i2c_gpio_state_suspend;

	if (!IS_ERR_OR_NULL(pins_i2c_state)) {
		int ret =  pinctrl_select_state(charger->i2c_pinctrl, pins_i2c_state);
		if (ret) {
			dev_err(charger->dev, "%s: Failed to set da9155 i2c pin state.\n", __func__);
			return ret;
		}
	}

	return 0;
}

static int da9155_i2c_pinctrl_init(struct da9155_charger_data *charger) {
	int ret = 0;
	struct pinctrl *i2c_pinctrl;

	charger->i2c_pinctrl = devm_pinctrl_get(&charger->i2c->dev);
	if (IS_ERR_OR_NULL(charger->i2c_pinctrl)) {
		dev_err(charger->dev, "%s: Failed to alloc mem for da9155 i2c pinctrl.\n", __func__);
		ret = PTR_ERR(charger->i2c_pinctrl);
		return -ENOMEM;
	}

	i2c_pinctrl = charger->i2c_pinctrl;

	charger->i2c_gpio_state_active = pinctrl_lookup_state(i2c_pinctrl, "da9155_active");
	if (IS_ERR_OR_NULL(charger->i2c_gpio_state_active)) {
		dev_err(charger->dev, "%s: Failed to set active state for da9155 i2c\n", __func__);
		ret = PTR_ERR(charger->i2c_gpio_state_active);
		goto err_i2c_active_state;
	}

	charger->i2c_gpio_state_suspend = pinctrl_lookup_state(i2c_pinctrl, "da9155_suspend");
	if (IS_ERR_OR_NULL(charger->i2c_gpio_state_suspend)) {
		dev_err(charger->dev, "%s: Failed to set suspend state for da9155 i2c\n", __func__);
		ret = PTR_ERR(charger->i2c_gpio_state_suspend);
		goto err_i2c_suspend_state;
	}

#if defined(CONFIG_OF)
	da9155_pinctrl_select(charger, true);
#endif
	return ret;

err_i2c_suspend_state:
	charger->i2c_gpio_state_suspend = 0;
err_i2c_active_state:
	charger->i2c_gpio_state_active = 0;
	return -1;
}

static ssize_t da9155_store_addr(struct device *dev,
			      struct device_attribute *attr,
			      const char *buf, size_t count)
{
	struct power_supply *psy = dev_get_drvdata(dev);
	struct da9155_charger_data *charger = container_of(psy, struct da9155_charger_data, psy_chg);
	int x;
	if (sscanf(buf, "0x%x\n", &x) == 1) {
		charger->addr = x;
	}
	return count;
}

static ssize_t da9155_show_addr(struct device *dev,
				   struct device_attribute *attr,
				   char *buf)
{
	struct power_supply *psy = dev_get_drvdata(dev);
	struct da9155_charger_data *charger = container_of(psy, struct da9155_charger_data, psy_chg);
	return sprintf(buf, "0x%x\n", charger->addr);
}

static ssize_t da9155_store_size(struct device *dev,
			      struct device_attribute *attr,
			      const char *buf, size_t count)
{
	struct power_supply *psy = dev_get_drvdata(dev);
	struct da9155_charger_data *charger = container_of(psy, struct da9155_charger_data, psy_chg);
	int x;
	if (sscanf(buf, "%d\n", &x) == 1) {
		charger->size = x;
	}
	return count;
}

static ssize_t da9155_show_size(struct device *dev,
				   struct device_attribute *attr,
				   char *buf)
{
	struct power_supply *psy = dev_get_drvdata(dev);
	struct da9155_charger_data *charger = container_of(psy, struct da9155_charger_data, psy_chg);
	return sprintf(buf, "0x%x\n", charger->size);
}
static ssize_t da9155_store_data(struct device *dev,
			      struct device_attribute *attr,
			      const char *buf, size_t count)
{
	struct power_supply *psy = dev_get_drvdata(dev);
	struct da9155_charger_data *charger = container_of(psy, struct da9155_charger_data, psy_chg);
	int x;

	if (sscanf(buf, "0x%x", &x) == 1) {
		u8 data = x;
		if (da9155_write_reg(charger->i2c, charger->addr, data) < 0)
		{
			dev_info(charger->dev,
					"%s: addr: 0x%x write fail\n", __func__, charger->addr);
		}
	}
	return count;
}

static ssize_t da9155_show_data(struct device *dev,
				   struct device_attribute *attr,
				   char *buf)
{
	struct power_supply *psy = dev_get_drvdata(dev);
	struct da9155_charger_data *charger = container_of(psy, struct da9155_charger_data, psy_chg);
	u8 data;
	int i, count = 0;;
	if (charger->size == 0)
		charger->size = 1;

	for (i = 0; i < charger->size; i++) {
		if (da9155_read_reg(charger->i2c, charger->addr+i, &data) < 0) {
			dev_info(charger->dev,
					"%s: read fail\n", __func__);
			count += sprintf(buf+count, "addr: 0x%x read fail\n", charger->addr+i);
			continue;
		}
		count += sprintf(buf+count, "addr: 0x%x, data: 0x%x\n", charger->addr+i,data);
	}
	return count;
}

static DEVICE_ATTR(addr, 0644, da9155_show_addr, da9155_store_addr);
static DEVICE_ATTR(size, 0644, da9155_show_size, da9155_store_size);
static DEVICE_ATTR(data, 0644, da9155_show_data, da9155_store_data);

static struct attribute *da9155_attributes[] = {
	&dev_attr_addr.attr,
	&dev_attr_size.attr,
	&dev_attr_data.attr,
	NULL
};

static const struct attribute_group da9155_attr_group = {
	.attrs = da9155_attributes,
};

static int da9155_charger_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
{
	struct device_node *of_node = client->dev.of_node;
	struct da9155_charger_data *charger;
	sec_charger_platform_data_t *pdata = client->dev.platform_data;
	int ret = 0;

	pr_info("%s: DA9155 Charger Driver Loading\n", __func__);

	if (of_node) {
		pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
		if (!pdata) {
			pr_err("%s: Failed to allocate memory\n", __func__);
			return -ENOMEM;
		}
		ret = da9155_charger_parse_dt(&client->dev, pdata);
		if (ret < 0)
			goto err_parse_dt;
	} else {
		pdata = client->dev.platform_data;
	}

	charger = kzalloc(sizeof(*charger), GFP_KERNEL);
	if (!charger) {
		pr_err("%s: Failed to allocate memory\n", __func__);
		ret = -ENOMEM;
		goto err_nomem;
	}

	mutex_init(&charger->io_lock);
	charger->dev = &client->dev;
	ret = i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
		I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_I2C_BLOCK);
	if (!ret) {
		ret = i2c_get_functionality(client->adapter);
		dev_err(charger->dev, "I2C functionality is not supported.\n");
		ret = -ENOSYS;
		goto err_i2cfunc_not_support;
	}
	charger->i2c = client;
	charger->pdata = pdata;
	i2c_set_clientdata(client, charger);

	if (da9155_i2c_pinctrl_init(charger) < 0)
		dev_err(charger->dev, "i2c_pinctrl is failed\n");

	charger->psy_chg.name			= "da9155-charger";
	charger->psy_chg.type			= POWER_SUPPLY_TYPE_UNKNOWN;
	charger->psy_chg.get_property	= da9155_chg_get_property;
	charger->psy_chg.set_property	= da9155_chg_set_property;
	charger->psy_chg.properties		= da9155_charger_props;
	charger->psy_chg.num_properties	= ARRAY_SIZE(da9155_charger_props);

	/* da9155_charger_initialize(charger); */
	charger->cable_type = POWER_SUPPLY_TYPE_BATTERY;

	ret = power_supply_register(charger->dev, &charger->psy_chg);
	if (ret) {
		pr_err("%s: Failed to Register psy_chg\n", __func__);
		ret = -1;
		goto err_power_supply_register;
	}

	charger->wqueue =
		create_singlethread_workqueue(dev_name(charger->dev));
	if (!charger->wqueue) {
		pr_err("%s: Fail to Create Workqueue\n", __func__);
		ret = -1;
		goto err_create_wqueue;
	}

	if (pdata->irq_gpio) {
		charger->chg_irq = gpio_to_irq(pdata->irq_gpio);

		ret = request_threaded_irq(charger->chg_irq, NULL,
			da9155_irq_handler,
			IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
			"da9155-irq", charger);
		if (ret < 0) {
			pr_err("%s: Failed to Request IRQ(%d)\n", __func__, ret);
			goto err_req_irq;
		}

		ret = enable_irq_wake(charger->chg_irq);
		if (ret < 0)
			pr_err("%s: Failed to Enable Wakeup Source(%d)\n",
				__func__, ret);
	}

	ret = sysfs_create_group(&charger->psy_chg.dev->kobj, &da9155_attr_group);
	if (ret) {
		dev_info(&client->dev,
			"%s: sysfs_create_group failed\n", __func__);
	}
	pr_info("%s: DA9155 Charger Driver Loaded\n", __func__);

	return 0;

err_req_irq:
err_create_wqueue:
	power_supply_unregister(&charger->psy_chg);
err_power_supply_register:
err_i2cfunc_not_support:
	mutex_destroy(&charger->io_lock);
	kfree(charger);
err_nomem:
err_parse_dt:
	kfree(pdata);

	return ret;
}

static int da9155_charger_remove(struct i2c_client *client)
{
	struct da9155_charger_data *charger = i2c_get_clientdata(client);

	free_irq(charger->chg_irq, NULL);
	destroy_workqueue(charger->wqueue);
	power_supply_unregister(&charger->psy_chg);
	mutex_destroy(&charger->io_lock);
	kfree(charger->pdata);
	kfree(charger);

	return 0;
}

static void da9155_charger_shutdown(struct i2c_client *client)
{
	da9155_update_reg(client, DA9155_BUCK_CONT, 0, DA9155_BUCK_EN_MASK);
	da9155_update_reg(client, DA9155_BUCK_IOUT, 0x7D, DA9155_BUCK_ILIM_MASK);
}

static const struct i2c_device_id da9155_charger_id_table[] = {
	{"da9155-charger", 0},
	{},
};
MODULE_DEVICE_TABLE(i2c, da9155_id_table);

#ifdef CONFIG_OF
static struct of_device_id da9155_charger_match_table[] = {
	{.compatible = "dlg,da9155-charger"},
	{},
};
#else
#define da9155_charger_match_table NULL
#endif

static struct i2c_driver da9155_charger_driver = {
	.driver = {
		.name	= "da9155-charger",
		.owner	= THIS_MODULE,
		.of_match_table = da9155_charger_match_table,
	},
	.probe		= da9155_charger_probe,
	.remove		= da9155_charger_remove,
	.shutdown	= da9155_charger_shutdown,
	.id_table	= da9155_charger_id_table,
};

static int __init da9155_charger_init(void)
{
	pr_info("%s: \n", __func__);
	return i2c_add_driver(&da9155_charger_driver);
}

static void __exit da9155_charger_exit(void)
{
	pr_info("%s: \n", __func__);
	i2c_del_driver(&da9155_charger_driver);
}

module_init(da9155_charger_init);
module_exit(da9155_charger_exit);

MODULE_DESCRIPTION("Samsung DA9155 Charger Driver");
MODULE_AUTHOR("Samsung Electronics");
MODULE_LICENSE("GPL");