drivers/power/max14577_charger.c - kernel/msm-4.9 - Gitiles

 /*
  * max14577_charger.c - Battery charger driver for the Maxim 14577/77836
  *
  * Copyright (C) 2013,2014 Samsung Electronics
  * Krzysztof Kozlowski <k.kozlowski@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/module.h>
 #include <linux/platform_device.h>
 #include <linux/power_supply.h>
 #include <linux/mfd/max14577-private.h>
 #include <linux/mfd/max14577.h>

 struct max14577_charger {
 	struct device *dev;
 	struct max14577	*max14577;
 	struct power_supply	charger;

 	unsigned int		charging_state;
 	unsigned int		battery_state;

 	struct max14577_charger_platform_data	*pdata;
 };

 /*
  * Helper function for mapping values of STATUS2/CHGTYP register on max14577
  * and max77836 chipsets to enum maxim_muic_charger_type.
  */
 static enum max14577_muic_charger_type maxim_get_charger_type(
 		enum maxim_device_type dev_type, u8 val) {
 	switch (val) {
 	case MAX14577_CHARGER_TYPE_NONE:
 	case MAX14577_CHARGER_TYPE_USB:
 	case MAX14577_CHARGER_TYPE_DOWNSTREAM_PORT:
 	case MAX14577_CHARGER_TYPE_DEDICATED_CHG:
 	case MAX14577_CHARGER_TYPE_SPECIAL_500MA:
 	case MAX14577_CHARGER_TYPE_SPECIAL_1A:
 		return val;
 	case MAX14577_CHARGER_TYPE_DEAD_BATTERY:
 	case MAX14577_CHARGER_TYPE_RESERVED:
 		if (dev_type == MAXIM_DEVICE_TYPE_MAX77836)
 			val |= 0x8;
 		return val;
 	default:
 		WARN_ONCE(1, "max14577: Unsupported chgtyp register value 0x%02x", val);
 		return val;
 	}
 }

 static int max14577_get_charger_state(struct max14577_charger *chg)
 {
 	struct regmap *rmap = chg->max14577->regmap;
 	int state = POWER_SUPPLY_STATUS_DISCHARGING;
 	u8 reg_data;

 	/*
 	 * Charging occurs only if:
 	 *  - CHGCTRL2/MBCHOSTEN == 1
 	 *  - STATUS2/CGMBC == 1
 	 *
 	 * TODO:
 	 *  - handle FULL after Top-off timer (EOC register may be off
 	 *    and the charger won't be charging although MBCHOSTEN is on)
 	 *  - handle properly dead-battery charging (respect timer)
 	 *  - handle timers (fast-charge and prequal) /MBCCHGERR/
 	 */
 	max14577_read_reg(rmap, MAX14577_CHG_REG_CHG_CTRL2, &reg_data);
 	if ((reg_data & CHGCTRL2_MBCHOSTEN_MASK) == 0)
 		goto state_set;

 	max14577_read_reg(rmap, MAX14577_CHG_REG_STATUS3, &reg_data);
 	if (reg_data & STATUS3_CGMBC_MASK) {
 		/* Charger or USB-cable is connected */
 		if (reg_data & STATUS3_EOC_MASK)
 			state = POWER_SUPPLY_STATUS_FULL;
 		else
 			state = POWER_SUPPLY_STATUS_CHARGING;
 		goto state_set;
 	}

 state_set:
 	chg->charging_state = state;
 	return state;
 }

 /*
  * Supported charge types:
  *  - POWER_SUPPLY_CHARGE_TYPE_NONE
  *  - POWER_SUPPLY_CHARGE_TYPE_FAST
  */
 static int max14577_get_charge_type(struct max14577_charger *chg)
 {
 	/*
 	 * TODO: CHARGE_TYPE_TRICKLE (VCHGR_RC or EOC)?
 	 * As spec says:
 	 * [after reaching EOC interrupt]
 	 * "When the battery is fully charged, the 30-minute (typ)
 	 *  top-off timer starts. The device continues to trickle
 	 *  charge the battery until the top-off timer runs out."
 	 */
 	if (max14577_get_charger_state(chg) == POWER_SUPPLY_STATUS_CHARGING)
 		return POWER_SUPPLY_CHARGE_TYPE_FAST;
 	return POWER_SUPPLY_CHARGE_TYPE_NONE;
 }

 static int max14577_get_online(struct max14577_charger *chg)
 {
 	struct regmap *rmap = chg->max14577->regmap;
 	u8 reg_data;
 	enum max14577_muic_charger_type chg_type;

 	max14577_read_reg(rmap, MAX14577_MUIC_REG_STATUS2, &reg_data);
 	reg_data = ((reg_data & STATUS2_CHGTYP_MASK) >> STATUS2_CHGTYP_SHIFT);
 	chg_type = maxim_get_charger_type(chg->max14577->dev_type, reg_data);
 	switch (chg_type) {
 	case MAX14577_CHARGER_TYPE_USB:
 	case MAX14577_CHARGER_TYPE_DEDICATED_CHG:
 	case MAX14577_CHARGER_TYPE_SPECIAL_500MA:
 	case MAX14577_CHARGER_TYPE_SPECIAL_1A:
 	case MAX14577_CHARGER_TYPE_DEAD_BATTERY:
 	case MAX77836_CHARGER_TYPE_SPECIAL_BIAS:
 		return 1;
 	case MAX14577_CHARGER_TYPE_NONE:
 	case MAX14577_CHARGER_TYPE_DOWNSTREAM_PORT:
 	case MAX14577_CHARGER_TYPE_RESERVED:
 	case MAX77836_CHARGER_TYPE_RESERVED:
 	default:
 		return 0;
 	}
 }

 /*
  * Supported health statuses:
  *  - POWER_SUPPLY_HEALTH_DEAD
  *  - POWER_SUPPLY_HEALTH_OVERVOLTAGE
  *  - POWER_SUPPLY_HEALTH_GOOD
  */
 static int max14577_get_battery_health(struct max14577_charger *chg)
 {
 	struct regmap *rmap = chg->max14577->regmap;
 	int state = POWER_SUPPLY_HEALTH_GOOD;
 	u8 reg_data;
 	enum max14577_muic_charger_type chg_type;

 	max14577_read_reg(rmap, MAX14577_MUIC_REG_STATUS2, &reg_data);
 	reg_data = ((reg_data & STATUS2_CHGTYP_MASK) >> STATUS2_CHGTYP_SHIFT);
 	chg_type = maxim_get_charger_type(chg->max14577->dev_type, reg_data);
 	if (chg_type == MAX14577_CHARGER_TYPE_DEAD_BATTERY) {
 		state = POWER_SUPPLY_HEALTH_DEAD;
 		goto state_set;
 	}

 	max14577_read_reg(rmap, MAX14577_CHG_REG_STATUS3, &reg_data);
 	if (reg_data & STATUS3_OVP_MASK) {
 		state = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
 		goto state_set;
 	}

 state_set:
 	chg->battery_state = state;
 	return state;
 }

 /*
  * Always returns 1.
  * The max14577 chip doesn't report any status of battery presence.
  * Lets assume that it will always be used with some battery.
  */
 static int max14577_get_present(struct max14577_charger *chg)
 {
 	return 1;
 }

 static int max14577_set_fast_charge_timer(struct max14577_charger *chg,
 		unsigned long hours)
 {
 	u8 reg_data;

 	switch (hours) {
 	case 5 ... 7:
 		reg_data = hours - 3;
 		break;
 	case 0:
 		/* Disable */
 		reg_data = 0x7;
 		break;
 	default:
 		dev_err(chg->dev, "Wrong value for Fast-Charge Timer: %lu\n",
 				hours);
 		return -EINVAL;
 	}
 	reg_data <<= CHGCTRL1_TCHW_SHIFT;

 	return max14577_update_reg(chg->max14577->regmap,
 			MAX14577_REG_CHGCTRL1, CHGCTRL1_TCHW_MASK, reg_data);
 }

 static int max14577_init_constant_voltage(struct max14577_charger *chg,
 		unsigned int uvolt)
 {
 	u8 reg_data;

 	if (uvolt < MAXIM_CHARGER_CONSTANT_VOLTAGE_MIN ||
 			uvolt > MAXIM_CHARGER_CONSTANT_VOLTAGE_MAX)
 		return -EINVAL;

 	if (uvolt == 4200000)
 		reg_data = 0x0;
 	else if (uvolt == MAXIM_CHARGER_CONSTANT_VOLTAGE_MAX)
 		reg_data = 0x1f;
 	else if (uvolt <= 4280000) {
 		unsigned int val = uvolt;

 		val -= MAXIM_CHARGER_CONSTANT_VOLTAGE_MIN;
 		val /= MAXIM_CHARGER_CONSTANT_VOLTAGE_STEP;
 		if (uvolt <= 4180000)
 			reg_data = 0x1 + val;
 		else
 			reg_data = val; /* Fix for gap between 4.18V and 4.22V */
 	} else
 		return -EINVAL;

 	reg_data <<= CHGCTRL3_MBCCVWRC_SHIFT;

 	return max14577_write_reg(chg->max14577->regmap,
 			MAX14577_CHG_REG_CHG_CTRL3, reg_data);
 }

 static int max14577_init_eoc(struct max14577_charger *chg,
 		unsigned int uamp)
 {
 	unsigned int current_bits = 0xf;
 	u8 reg_data;

 	switch (chg->max14577->dev_type) {
 	case MAXIM_DEVICE_TYPE_MAX77836:
 		if (uamp < 5000)
 			return -EINVAL; /* Requested current is too low */

 		if (uamp >= 7500 && uamp < 10000)
 			current_bits = 0x0;
 		else if (uamp <= 50000) {
 			/* <5000, 7499> and <10000, 50000> */
 			current_bits = uamp / 5000;
 		} else {
 			uamp = min(uamp, 100000U) - 50000U;
 			current_bits = 0xa + uamp / 10000;
 		}
 		break;

 	case MAXIM_DEVICE_TYPE_MAX14577:
 	default:
 		if (uamp < MAX14577_CHARGER_EOC_CURRENT_LIMIT_MIN)
 			return -EINVAL; /* Requested current is too low */

 		uamp = min(uamp, MAX14577_CHARGER_EOC_CURRENT_LIMIT_MAX);
 		uamp -= MAX14577_CHARGER_EOC_CURRENT_LIMIT_MIN;
 		current_bits = uamp / MAX14577_CHARGER_EOC_CURRENT_LIMIT_STEP;
 		break;
 	}

 	reg_data = current_bits << CHGCTRL5_EOCS_SHIFT;

 	return max14577_update_reg(chg->max14577->regmap,
 			MAX14577_CHG_REG_CHG_CTRL5, CHGCTRL5_EOCS_MASK,
 			reg_data);
 }

 static int max14577_init_fast_charge(struct max14577_charger *chg,
 		unsigned int uamp)
 {
 	u8 reg_data;
 	int ret;
 	const struct maxim_charger_current *limits =
 		&maxim_charger_currents[chg->max14577->dev_type];

 	ret = maxim_charger_calc_reg_current(limits, uamp, uamp, &reg_data);
 	if (ret) {
 		dev_err(chg->dev, "Wrong value for fast charge: %u\n", uamp);
 		return ret;
 	}

 	return max14577_update_reg(chg->max14577->regmap,
 			MAX14577_CHG_REG_CHG_CTRL4,
 			CHGCTRL4_MBCICHWRCL_MASK | CHGCTRL4_MBCICHWRCH_MASK,
 			reg_data);
 }

 /*
  * Sets charger registers to proper and safe default values.
  * Some of these values are equal to defaults in MAX14577E
  * data sheet but there are minor differences.
  */
 static int max14577_charger_reg_init(struct max14577_charger *chg)
 {
 	struct regmap *rmap = chg->max14577->regmap;
 	u8 reg_data;
 	int ret;

 	/*
 	 * Charger-Type Manual Detection, default off (set CHGTYPMAN to 0)
 	 * Charger-Detection Enable, default on (set CHGDETEN to 1)
 	 * Combined mask of CHGDETEN and CHGTYPMAN will zero the CHGTYPMAN bit
 	 */
 	reg_data = 0x1 << CDETCTRL1_CHGDETEN_SHIFT;
 	max14577_update_reg(rmap, MAX14577_REG_CDETCTRL1,
 			CDETCTRL1_CHGDETEN_MASK | CDETCTRL1_CHGTYPMAN_MASK,
 			reg_data);

 	/*
 	 * Wall-Adapter Rapid Charge, default on
 	 * Battery-Charger, default on
 	 */
 	reg_data = 0x1 << CHGCTRL2_VCHGR_RC_SHIFT;
 	reg_data |= 0x1 << CHGCTRL2_MBCHOSTEN_SHIFT;
 	max14577_write_reg(rmap, MAX14577_REG_CHGCTRL2, reg_data);

 	/* Auto Charging Stop, default off */
 	reg_data = 0x0 << CHGCTRL6_AUTOSTOP_SHIFT;
 	max14577_write_reg(rmap, MAX14577_REG_CHGCTRL6, reg_data);

 	ret = max14577_init_constant_voltage(chg, chg->pdata->constant_uvolt);
 	if (ret)
 		return ret;

 	ret = max14577_init_eoc(chg, chg->pdata->eoc_uamp);
 	if (ret)
 		return ret;

 	ret = max14577_init_fast_charge(chg, chg->pdata->fast_charge_uamp);
 	if (ret)
 		return ret;

 	ret = max14577_set_fast_charge_timer(chg,
 			MAXIM_CHARGER_FAST_CHARGE_TIMER_DEFAULT);
 	if (ret)
 		return ret;

 	/* Initialize Overvoltage-Protection Threshold */
 	switch (chg->pdata->ovp_uvolt) {
 	case 7500000:
 		reg_data = 0x0;
 		break;
 	case 6000000:
 	case 6500000:
 	case 7000000:
 		reg_data = 0x1 + (chg->pdata->ovp_uvolt - 6000000) / 500000;
 		break;
 	default:
 		dev_err(chg->dev, "Wrong value for OVP: %u\n",
 				chg->pdata->ovp_uvolt);
 		return -EINVAL;
 	}
 	reg_data <<= CHGCTRL7_OTPCGHCVS_SHIFT;
 	max14577_write_reg(rmap, MAX14577_REG_CHGCTRL7, reg_data);

 	return 0;
 }

 /* Support property from charger */
 static enum power_supply_property max14577_charger_props[] = {
 	POWER_SUPPLY_PROP_STATUS,
 	POWER_SUPPLY_PROP_CHARGE_TYPE,
 	POWER_SUPPLY_PROP_HEALTH,
 	POWER_SUPPLY_PROP_PRESENT,
 	POWER_SUPPLY_PROP_ONLINE,
 	POWER_SUPPLY_PROP_MODEL_NAME,
 	POWER_SUPPLY_PROP_MANUFACTURER,
 };

 static const char * const model_names[] = {
 	[MAXIM_DEVICE_TYPE_UNKNOWN]	= "MAX14577-like",
 	[MAXIM_DEVICE_TYPE_MAX14577]	= "MAX14577",
 	[MAXIM_DEVICE_TYPE_MAX77836]	= "MAX77836",
 };
 static const char *manufacturer = "Maxim Integrated";

 static int max14577_charger_get_property(struct power_supply *psy,
 			    enum power_supply_property psp,
 			    union power_supply_propval *val)
 {
 	struct max14577_charger *chg = container_of(psy,
 						  struct max14577_charger,
 						  charger);
 	int ret = 0;

 	switch (psp) {
 	case POWER_SUPPLY_PROP_STATUS:
 		val->intval = max14577_get_charger_state(chg);
 		break;
 	case POWER_SUPPLY_PROP_CHARGE_TYPE:
 		val->intval = max14577_get_charge_type(chg);
 		break;
 	case POWER_SUPPLY_PROP_HEALTH:
 		val->intval = max14577_get_battery_health(chg);
 		break;
 	case POWER_SUPPLY_PROP_PRESENT:
 		val->intval = max14577_get_present(chg);
 		break;
 	case POWER_SUPPLY_PROP_ONLINE:
 		val->intval = max14577_get_online(chg);
 		break;
 	case POWER_SUPPLY_PROP_MODEL_NAME:
 		BUILD_BUG_ON(ARRAY_SIZE(model_names) != MAXIM_DEVICE_TYPE_NUM);
 		val->strval = model_names[chg->max14577->dev_type];
 		break;
 	case POWER_SUPPLY_PROP_MANUFACTURER:
 		val->strval = manufacturer;
 		break;
 	default:
 		return -EINVAL;
 	}

 	return ret;
 }

 #ifdef CONFIG_OF
 static struct max14577_charger_platform_data *max14577_charger_dt_init(
 		struct platform_device *pdev)
 {
 	struct max14577_charger_platform_data *pdata;
 	struct device_node *np = pdev->dev.of_node;
 	int ret;

 	if (!np) {
 		dev_err(&pdev->dev, "No charger OF node\n");
 		return ERR_PTR(-EINVAL);
 	}

 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
 		return ERR_PTR(-ENOMEM);

 	ret = of_property_read_u32(np, "maxim,constant-uvolt",
 			&pdata->constant_uvolt);
 	if (ret) {
 		dev_err(&pdev->dev, "Cannot parse maxim,constant-uvolt field from DT\n");
 		return ERR_PTR(ret);
 	}

 	ret = of_property_read_u32(np, "maxim,fast-charge-uamp",
 			&pdata->fast_charge_uamp);
 	if (ret) {
 		dev_err(&pdev->dev, "Cannot parse maxim,fast-charge-uamp field from DT\n");
 		return ERR_PTR(ret);
 	}

 	ret = of_property_read_u32(np, "maxim,eoc-uamp", &pdata->eoc_uamp);
 	if (ret) {
 		dev_err(&pdev->dev, "Cannot parse maxim,eoc-uamp field from DT\n");
 		return ERR_PTR(ret);
 	}

 	ret = of_property_read_u32(np, "maxim,ovp-uvolt", &pdata->ovp_uvolt);
 	if (ret) {
 		dev_err(&pdev->dev, "Cannot parse maxim,ovp-uvolt field from DT\n");
 		return ERR_PTR(ret);
 	}

 	return pdata;
 }
 #else /* CONFIG_OF */
 static struct max14577_charger_platform_data *max14577_charger_dt_init(
 		struct platform_device *pdev)
 {
 	return NULL;
 }
 #endif /* CONFIG_OF */

 static ssize_t show_fast_charge_timer(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	struct max14577_charger *chg = dev_get_drvdata(dev);
 	u8 reg_data;
 	int ret;
 	unsigned int val;

 	ret = max14577_read_reg(chg->max14577->regmap, MAX14577_REG_CHGCTRL1,
 			&reg_data);
 	if (ret)
 		return ret;

 	reg_data &= CHGCTRL1_TCHW_MASK;
 	reg_data >>= CHGCTRL1_TCHW_SHIFT;
 	switch (reg_data) {
 	case 0x2 ... 0x4:
 		val = reg_data + 3;
 		break;
 	case 0x7:
 		val = 0;
 		break;
 	default:
 		val = 5;
 		break;
 	}

 	return scnprintf(buf, PAGE_SIZE, "%u\n", val);
 }

 static ssize_t store_fast_charge_timer(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t count)
 {
 	struct max14577_charger *chg = dev_get_drvdata(dev);
 	unsigned long val;
 	int ret;

 	ret = kstrtoul(buf, 10, &val);
 	if (ret)
 		return ret;

 	ret = max14577_set_fast_charge_timer(chg, val);
 	if (ret)
 		return ret;

 	return count;
 }

 static DEVICE_ATTR(fast_charge_timer, S_IRUGO | S_IWUSR,
 		show_fast_charge_timer, store_fast_charge_timer);

 static int max14577_charger_probe(struct platform_device *pdev)
 {
 	struct max14577_charger *chg;
 	struct max14577 *max14577 = dev_get_drvdata(pdev->dev.parent);
 	int ret;

 	chg = devm_kzalloc(&pdev->dev, sizeof(*chg), GFP_KERNEL);
 	if (!chg)
 		return -ENOMEM;

 	platform_set_drvdata(pdev, chg);
 	chg->dev = &pdev->dev;
 	chg->max14577 = max14577;

 	chg->pdata = max14577_charger_dt_init(pdev);
 	if (IS_ERR_OR_NULL(chg->pdata))
 		return PTR_ERR(chg->pdata);

 	ret = max14577_charger_reg_init(chg);
 	if (ret)
 		return ret;

 	chg->charger.name = "max14577-charger",
 	chg->charger.type = POWER_SUPPLY_TYPE_BATTERY,
 	chg->charger.properties = max14577_charger_props,
 	chg->charger.num_properties = ARRAY_SIZE(max14577_charger_props),
 	chg->charger.get_property = max14577_charger_get_property,

 	ret = device_create_file(&pdev->dev, &dev_attr_fast_charge_timer);
 	if (ret) {
 		dev_err(&pdev->dev, "failed: create sysfs entry\n");
 		return ret;
 	}

 	ret = power_supply_register(&pdev->dev, &chg->charger);
 	if (ret) {
 		dev_err(&pdev->dev, "failed: power supply register\n");
 		goto err;
 	}

 	/* Check for valid values for charger */
 	BUILD_BUG_ON(MAX14577_CHARGER_EOC_CURRENT_LIMIT_MIN +
 			MAX14577_CHARGER_EOC_CURRENT_LIMIT_STEP * 0xf !=
 			MAX14577_CHARGER_EOC_CURRENT_LIMIT_MAX);
 	return 0;

 err:
 	device_remove_file(&pdev->dev, &dev_attr_fast_charge_timer);

 	return ret;
 }

 static int max14577_charger_remove(struct platform_device *pdev)
 {
 	struct max14577_charger *chg = platform_get_drvdata(pdev);

 	device_remove_file(&pdev->dev, &dev_attr_fast_charge_timer);
 	power_supply_unregister(&chg->charger);

 	return 0;
 }

 static const struct platform_device_id max14577_charger_id[] = {
 	{ "max14577-charger", MAXIM_DEVICE_TYPE_MAX14577, },
 	{ "max77836-charger", MAXIM_DEVICE_TYPE_MAX77836, },
 	{ }
 };
 MODULE_DEVICE_TABLE(platform, max14577_charger_id);

 static struct platform_driver max14577_charger_driver = {
 	.driver = {
 		.name	= "max14577-charger",
 	},
 	.probe		= max14577_charger_probe,
 	.remove		= max14577_charger_remove,
 	.id_table	= max14577_charger_id,
 };
 module_platform_driver(max14577_charger_driver);

 MODULE_AUTHOR("Krzysztof Kozlowski <k.kozlowski@samsung.com>");
 MODULE_DESCRIPTION("Maxim 14577/77836 charger driver");
 MODULE_LICENSE("GPL");
	/*
	* max14577_charger.c - Battery charger driver for the Maxim 14577/77836
	*
	* Copyright (C) 2013,2014 Samsung Electronics
	* Krzysztof Kozlowski <k.kozlowski@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/module.h>
	#include <linux/platform_device.h>
	#include <linux/power_supply.h>
	#include <linux/mfd/max14577-private.h>
	#include <linux/mfd/max14577.h>

	struct max14577_charger {
	struct device *dev;
	struct max14577 *max14577;
	struct power_supply charger;

	unsigned int charging_state;
	unsigned int battery_state;

	struct max14577_charger_platform_data *pdata;
	};

	/*
	* Helper function for mapping values of STATUS2/CHGTYP register on max14577
	* and max77836 chipsets to enum maxim_muic_charger_type.
	*/
	static enum max14577_muic_charger_type maxim_get_charger_type(
	enum maxim_device_type dev_type, u8 val) {
	switch (val) {
	case MAX14577_CHARGER_TYPE_NONE:
	case MAX14577_CHARGER_TYPE_USB:
	case MAX14577_CHARGER_TYPE_DOWNSTREAM_PORT:
	case MAX14577_CHARGER_TYPE_DEDICATED_CHG:
	case MAX14577_CHARGER_TYPE_SPECIAL_500MA:
	case MAX14577_CHARGER_TYPE_SPECIAL_1A:
	return val;
	case MAX14577_CHARGER_TYPE_DEAD_BATTERY:
	case MAX14577_CHARGER_TYPE_RESERVED:
	if (dev_type == MAXIM_DEVICE_TYPE_MAX77836)
	val \|= 0x8;
	return val;
	default:
	WARN_ONCE(1, "max14577: Unsupported chgtyp register value 0x%02x", val);
	return val;
	}
	}

	static int max14577_get_charger_state(struct max14577_charger *chg)
	{
	struct regmap *rmap = chg->max14577->regmap;
	int state = POWER_SUPPLY_STATUS_DISCHARGING;
	u8 reg_data;

	/*
	* Charging occurs only if:
	* - CHGCTRL2/MBCHOSTEN == 1
	* - STATUS2/CGMBC == 1
	*
	* TODO:
	* - handle FULL after Top-off timer (EOC register may be off
	* and the charger won't be charging although MBCHOSTEN is on)
	* - handle properly dead-battery charging (respect timer)
	* - handle timers (fast-charge and prequal) /MBCCHGERR/
	*/
	max14577_read_reg(rmap, MAX14577_CHG_REG_CHG_CTRL2, &reg_data);
	if ((reg_data & CHGCTRL2_MBCHOSTEN_MASK) == 0)
	goto state_set;

	max14577_read_reg(rmap, MAX14577_CHG_REG_STATUS3, &reg_data);
	if (reg_data & STATUS3_CGMBC_MASK) {
	/* Charger or USB-cable is connected */
	if (reg_data & STATUS3_EOC_MASK)
	state = POWER_SUPPLY_STATUS_FULL;
	else
	state = POWER_SUPPLY_STATUS_CHARGING;
	goto state_set;
	}

	state_set:
	chg->charging_state = state;
	return state;
	}

	/*
	* Supported charge types:
	* - POWER_SUPPLY_CHARGE_TYPE_NONE
	* - POWER_SUPPLY_CHARGE_TYPE_FAST
	*/
	static int max14577_get_charge_type(struct max14577_charger *chg)
	{
	/*
	* TODO: CHARGE_TYPE_TRICKLE (VCHGR_RC or EOC)?
	* As spec says:
	* [after reaching EOC interrupt]
	* "When the battery is fully charged, the 30-minute (typ)
	* top-off timer starts. The device continues to trickle
	* charge the battery until the top-off timer runs out."
	*/
	if (max14577_get_charger_state(chg) == POWER_SUPPLY_STATUS_CHARGING)
	return POWER_SUPPLY_CHARGE_TYPE_FAST;
	return POWER_SUPPLY_CHARGE_TYPE_NONE;
	}

	static int max14577_get_online(struct max14577_charger *chg)
	{
	struct regmap *rmap = chg->max14577->regmap;
	u8 reg_data;
	enum max14577_muic_charger_type chg_type;

	max14577_read_reg(rmap, MAX14577_MUIC_REG_STATUS2, &reg_data);
	reg_data = ((reg_data & STATUS2_CHGTYP_MASK) >> STATUS2_CHGTYP_SHIFT);
	chg_type = maxim_get_charger_type(chg->max14577->dev_type, reg_data);
	switch (chg_type) {
	case MAX14577_CHARGER_TYPE_USB:
	case MAX14577_CHARGER_TYPE_DEDICATED_CHG:
	case MAX14577_CHARGER_TYPE_SPECIAL_500MA:
	case MAX14577_CHARGER_TYPE_SPECIAL_1A:
	case MAX14577_CHARGER_TYPE_DEAD_BATTERY:
	case MAX77836_CHARGER_TYPE_SPECIAL_BIAS:
	return 1;
	case MAX14577_CHARGER_TYPE_NONE:
	case MAX14577_CHARGER_TYPE_DOWNSTREAM_PORT:
	case MAX14577_CHARGER_TYPE_RESERVED:
	case MAX77836_CHARGER_TYPE_RESERVED:
	default:
	return 0;
	}
	}

	/*
	* Supported health statuses:
	* - POWER_SUPPLY_HEALTH_DEAD
	* - POWER_SUPPLY_HEALTH_OVERVOLTAGE
	* - POWER_SUPPLY_HEALTH_GOOD
	*/
	static int max14577_get_battery_health(struct max14577_charger *chg)
	{
	struct regmap *rmap = chg->max14577->regmap;
	int state = POWER_SUPPLY_HEALTH_GOOD;
	u8 reg_data;
	enum max14577_muic_charger_type chg_type;

	max14577_read_reg(rmap, MAX14577_MUIC_REG_STATUS2, &reg_data);
	reg_data = ((reg_data & STATUS2_CHGTYP_MASK) >> STATUS2_CHGTYP_SHIFT);
	chg_type = maxim_get_charger_type(chg->max14577->dev_type, reg_data);
	if (chg_type == MAX14577_CHARGER_TYPE_DEAD_BATTERY) {
	state = POWER_SUPPLY_HEALTH_DEAD;
	goto state_set;
	}

	max14577_read_reg(rmap, MAX14577_CHG_REG_STATUS3, &reg_data);
	if (reg_data & STATUS3_OVP_MASK) {
	state = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
	goto state_set;
	}

	state_set:
	chg->battery_state = state;
	return state;
	}

	/*
	* Always returns 1.
	* The max14577 chip doesn't report any status of battery presence.
	* Lets assume that it will always be used with some battery.
	*/
	static int max14577_get_present(struct max14577_charger *chg)
	{
	return 1;
	}

	static int max14577_set_fast_charge_timer(struct max14577_charger *chg,
	unsigned long hours)
	{
	u8 reg_data;

	switch (hours) {
	case 5 ... 7:
	reg_data = hours - 3;
	break;
	case 0:
	/* Disable */
	reg_data = 0x7;
	break;
	default:
	dev_err(chg->dev, "Wrong value for Fast-Charge Timer: %lu\n",
	hours);
	return -EINVAL;
	}
	reg_data <<= CHGCTRL1_TCHW_SHIFT;

	return max14577_update_reg(chg->max14577->regmap,
	MAX14577_REG_CHGCTRL1, CHGCTRL1_TCHW_MASK, reg_data);
	}

	static int max14577_init_constant_voltage(struct max14577_charger *chg,
	unsigned int uvolt)
	{
	u8 reg_data;

	if (uvolt < MAXIM_CHARGER_CONSTANT_VOLTAGE_MIN \|\|
	uvolt > MAXIM_CHARGER_CONSTANT_VOLTAGE_MAX)
	return -EINVAL;

	if (uvolt == 4200000)
	reg_data = 0x0;
	else if (uvolt == MAXIM_CHARGER_CONSTANT_VOLTAGE_MAX)
	reg_data = 0x1f;
	else if (uvolt <= 4280000) {
	unsigned int val = uvolt;

	val -= MAXIM_CHARGER_CONSTANT_VOLTAGE_MIN;
	val /= MAXIM_CHARGER_CONSTANT_VOLTAGE_STEP;
	if (uvolt <= 4180000)
	reg_data = 0x1 + val;
	else
	reg_data = val; /* Fix for gap between 4.18V and 4.22V */
	} else
	return -EINVAL;

	reg_data <<= CHGCTRL3_MBCCVWRC_SHIFT;

	return max14577_write_reg(chg->max14577->regmap,
	MAX14577_CHG_REG_CHG_CTRL3, reg_data);
	}

	static int max14577_init_eoc(struct max14577_charger *chg,
	unsigned int uamp)
	{
	unsigned int current_bits = 0xf;
	u8 reg_data;

	switch (chg->max14577->dev_type) {
	case MAXIM_DEVICE_TYPE_MAX77836:
	if (uamp < 5000)
	return -EINVAL; /* Requested current is too low */

	if (uamp >= 7500 && uamp < 10000)
	current_bits = 0x0;
	else if (uamp <= 50000) {
	/* <5000, 7499> and <10000, 50000> */
	current_bits = uamp / 5000;
	} else {
	uamp = min(uamp, 100000U) - 50000U;
	current_bits = 0xa + uamp / 10000;
	}
	break;

	case MAXIM_DEVICE_TYPE_MAX14577:
	default:
	if (uamp < MAX14577_CHARGER_EOC_CURRENT_LIMIT_MIN)
	return -EINVAL; /* Requested current is too low */

	uamp = min(uamp, MAX14577_CHARGER_EOC_CURRENT_LIMIT_MAX);
	uamp -= MAX14577_CHARGER_EOC_CURRENT_LIMIT_MIN;
	current_bits = uamp / MAX14577_CHARGER_EOC_CURRENT_LIMIT_STEP;
	break;
	}

	reg_data = current_bits << CHGCTRL5_EOCS_SHIFT;

	return max14577_update_reg(chg->max14577->regmap,
	MAX14577_CHG_REG_CHG_CTRL5, CHGCTRL5_EOCS_MASK,
	reg_data);
	}

	static int max14577_init_fast_charge(struct max14577_charger *chg,
	unsigned int uamp)
	{
	u8 reg_data;
	int ret;
	const struct maxim_charger_current *limits =
	&maxim_charger_currents[chg->max14577->dev_type];

	ret = maxim_charger_calc_reg_current(limits, uamp, uamp, &reg_data);
	if (ret) {
	dev_err(chg->dev, "Wrong value for fast charge: %u\n", uamp);
	return ret;
	}

	return max14577_update_reg(chg->max14577->regmap,
	MAX14577_CHG_REG_CHG_CTRL4,
	CHGCTRL4_MBCICHWRCL_MASK \| CHGCTRL4_MBCICHWRCH_MASK,
	reg_data);
	}

	/*
	* Sets charger registers to proper and safe default values.
	* Some of these values are equal to defaults in MAX14577E
	* data sheet but there are minor differences.
	*/
	static int max14577_charger_reg_init(struct max14577_charger *chg)
	{
	struct regmap *rmap = chg->max14577->regmap;
	u8 reg_data;
	int ret;

	/*
	* Charger-Type Manual Detection, default off (set CHGTYPMAN to 0)
	* Charger-Detection Enable, default on (set CHGDETEN to 1)
	* Combined mask of CHGDETEN and CHGTYPMAN will zero the CHGTYPMAN bit
	*/
	reg_data = 0x1 << CDETCTRL1_CHGDETEN_SHIFT;
	max14577_update_reg(rmap, MAX14577_REG_CDETCTRL1,
	CDETCTRL1_CHGDETEN_MASK \| CDETCTRL1_CHGTYPMAN_MASK,
	reg_data);

	/*
	* Wall-Adapter Rapid Charge, default on
	* Battery-Charger, default on
	*/
	reg_data = 0x1 << CHGCTRL2_VCHGR_RC_SHIFT;
	reg_data \|= 0x1 << CHGCTRL2_MBCHOSTEN_SHIFT;
	max14577_write_reg(rmap, MAX14577_REG_CHGCTRL2, reg_data);

	/* Auto Charging Stop, default off */
	reg_data = 0x0 << CHGCTRL6_AUTOSTOP_SHIFT;
	max14577_write_reg(rmap, MAX14577_REG_CHGCTRL6, reg_data);

	ret = max14577_init_constant_voltage(chg, chg->pdata->constant_uvolt);
	if (ret)
	return ret;

	ret = max14577_init_eoc(chg, chg->pdata->eoc_uamp);
	if (ret)
	return ret;

	ret = max14577_init_fast_charge(chg, chg->pdata->fast_charge_uamp);
	if (ret)
	return ret;

	ret = max14577_set_fast_charge_timer(chg,
	MAXIM_CHARGER_FAST_CHARGE_TIMER_DEFAULT);
	if (ret)
	return ret;

	/* Initialize Overvoltage-Protection Threshold */
	switch (chg->pdata->ovp_uvolt) {
	case 7500000:
	reg_data = 0x0;
	break;
	case 6000000:
	case 6500000:
	case 7000000:
	reg_data = 0x1 + (chg->pdata->ovp_uvolt - 6000000) / 500000;
	break;
	default:
	dev_err(chg->dev, "Wrong value for OVP: %u\n",
	chg->pdata->ovp_uvolt);
	return -EINVAL;
	}
	reg_data <<= CHGCTRL7_OTPCGHCVS_SHIFT;
	max14577_write_reg(rmap, MAX14577_REG_CHGCTRL7, reg_data);

	return 0;
	}

	/* Support property from charger */
	static enum power_supply_property max14577_charger_props[] = {
	POWER_SUPPLY_PROP_STATUS,
	POWER_SUPPLY_PROP_CHARGE_TYPE,
	POWER_SUPPLY_PROP_HEALTH,
	POWER_SUPPLY_PROP_PRESENT,
	POWER_SUPPLY_PROP_ONLINE,
	POWER_SUPPLY_PROP_MODEL_NAME,
	POWER_SUPPLY_PROP_MANUFACTURER,
	};

	static const char * const model_names[] = {
	[MAXIM_DEVICE_TYPE_UNKNOWN] = "MAX14577-like",
	[MAXIM_DEVICE_TYPE_MAX14577] = "MAX14577",
	[MAXIM_DEVICE_TYPE_MAX77836] = "MAX77836",
	};
	static const char *manufacturer = "Maxim Integrated";

	static int max14577_charger_get_property(struct power_supply *psy,
	enum power_supply_property psp,
	union power_supply_propval *val)
	{
	struct max14577_charger *chg = container_of(psy,
	struct max14577_charger,
	charger);
	int ret = 0;

	switch (psp) {
	case POWER_SUPPLY_PROP_STATUS:
	val->intval = max14577_get_charger_state(chg);
	break;
	case POWER_SUPPLY_PROP_CHARGE_TYPE:
	val->intval = max14577_get_charge_type(chg);
	break;
	case POWER_SUPPLY_PROP_HEALTH:
	val->intval = max14577_get_battery_health(chg);
	break;
	case POWER_SUPPLY_PROP_PRESENT:
	val->intval = max14577_get_present(chg);
	break;
	case POWER_SUPPLY_PROP_ONLINE:
	val->intval = max14577_get_online(chg);
	break;
	case POWER_SUPPLY_PROP_MODEL_NAME:
	BUILD_BUG_ON(ARRAY_SIZE(model_names) != MAXIM_DEVICE_TYPE_NUM);
	val->strval = model_names[chg->max14577->dev_type];
	break;
	case POWER_SUPPLY_PROP_MANUFACTURER:
	val->strval = manufacturer;
	break;
	default:
	return -EINVAL;
	}

	return ret;
	}

	#ifdef CONFIG_OF
	static struct max14577_charger_platform_data *max14577_charger_dt_init(
	struct platform_device *pdev)
	{
	struct max14577_charger_platform_data *pdata;
	struct device_node *np = pdev->dev.of_node;
	int ret;

	if (!np) {
	dev_err(&pdev->dev, "No charger OF node\n");
	return ERR_PTR(-EINVAL);
	}

	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata)
	return ERR_PTR(-ENOMEM);

	ret = of_property_read_u32(np, "maxim,constant-uvolt",
	&pdata->constant_uvolt);
	if (ret) {
	dev_err(&pdev->dev, "Cannot parse maxim,constant-uvolt field from DT\n");
	return ERR_PTR(ret);
	}

	ret = of_property_read_u32(np, "maxim,fast-charge-uamp",
	&pdata->fast_charge_uamp);
	if (ret) {
	dev_err(&pdev->dev, "Cannot parse maxim,fast-charge-uamp field from DT\n");
	return ERR_PTR(ret);
	}

	ret = of_property_read_u32(np, "maxim,eoc-uamp", &pdata->eoc_uamp);
	if (ret) {
	dev_err(&pdev->dev, "Cannot parse maxim,eoc-uamp field from DT\n");
	return ERR_PTR(ret);
	}

	ret = of_property_read_u32(np, "maxim,ovp-uvolt", &pdata->ovp_uvolt);
	if (ret) {
	dev_err(&pdev->dev, "Cannot parse maxim,ovp-uvolt field from DT\n");
	return ERR_PTR(ret);
	}

	return pdata;
	}
	#else /* CONFIG_OF */
	static struct max14577_charger_platform_data *max14577_charger_dt_init(
	struct platform_device *pdev)
	{
	return NULL;
	}
	#endif /* CONFIG_OF */

	static ssize_t show_fast_charge_timer(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct max14577_charger *chg = dev_get_drvdata(dev);
	u8 reg_data;
	int ret;
	unsigned int val;

	ret = max14577_read_reg(chg->max14577->regmap, MAX14577_REG_CHGCTRL1,
	&reg_data);
	if (ret)
	return ret;

	reg_data &= CHGCTRL1_TCHW_MASK;
	reg_data >>= CHGCTRL1_TCHW_SHIFT;
	switch (reg_data) {
	case 0x2 ... 0x4:
	val = reg_data + 3;
	break;
	case 0x7:
	val = 0;
	break;
	default:
	val = 5;
	break;
	}

	return scnprintf(buf, PAGE_SIZE, "%u\n", val);
	}

	static ssize_t store_fast_charge_timer(struct device *dev,
	struct device_attribute attr, const char buf, size_t count)
	{
	struct max14577_charger *chg = dev_get_drvdata(dev);
	unsigned long val;
	int ret;

	ret = kstrtoul(buf, 10, &val);
	if (ret)
	return ret;

	ret = max14577_set_fast_charge_timer(chg, val);
	if (ret)
	return ret;

	return count;
	}

	static DEVICE_ATTR(fast_charge_timer, S_IRUGO \| S_IWUSR,
	show_fast_charge_timer, store_fast_charge_timer);

	static int max14577_charger_probe(struct platform_device *pdev)
	{
	struct max14577_charger *chg;
	struct max14577 *max14577 = dev_get_drvdata(pdev->dev.parent);
	int ret;

	chg = devm_kzalloc(&pdev->dev, sizeof(*chg), GFP_KERNEL);
	if (!chg)
	return -ENOMEM;

	platform_set_drvdata(pdev, chg);
	chg->dev = &pdev->dev;
	chg->max14577 = max14577;

	chg->pdata = max14577_charger_dt_init(pdev);
	if (IS_ERR_OR_NULL(chg->pdata))
	return PTR_ERR(chg->pdata);

	ret = max14577_charger_reg_init(chg);
	if (ret)
	return ret;

	chg->charger.name = "max14577-charger",
	chg->charger.type = POWER_SUPPLY_TYPE_BATTERY,
	chg->charger.properties = max14577_charger_props,
	chg->charger.num_properties = ARRAY_SIZE(max14577_charger_props),
	chg->charger.get_property = max14577_charger_get_property,

	ret = device_create_file(&pdev->dev, &dev_attr_fast_charge_timer);
	if (ret) {
	dev_err(&pdev->dev, "failed: create sysfs entry\n");
	return ret;
	}

	ret = power_supply_register(&pdev->dev, &chg->charger);
	if (ret) {
	dev_err(&pdev->dev, "failed: power supply register\n");
	goto err;
	}

	/* Check for valid values for charger */
	BUILD_BUG_ON(MAX14577_CHARGER_EOC_CURRENT_LIMIT_MIN +
	MAX14577_CHARGER_EOC_CURRENT_LIMIT_STEP * 0xf !=
	MAX14577_CHARGER_EOC_CURRENT_LIMIT_MAX);
	return 0;

	err:
	device_remove_file(&pdev->dev, &dev_attr_fast_charge_timer);

	return ret;
	}

	static int max14577_charger_remove(struct platform_device *pdev)
	{
	struct max14577_charger *chg = platform_get_drvdata(pdev);

	device_remove_file(&pdev->dev, &dev_attr_fast_charge_timer);
	power_supply_unregister(&chg->charger);

	return 0;
	}

	static const struct platform_device_id max14577_charger_id[] = {
	{ "max14577-charger", MAXIM_DEVICE_TYPE_MAX14577, },
	{ "max77836-charger", MAXIM_DEVICE_TYPE_MAX77836, },
	{ }
	};
	MODULE_DEVICE_TABLE(platform, max14577_charger_id);

	static struct platform_driver max14577_charger_driver = {
	.driver = {
	.name = "max14577-charger",
	},
	.probe = max14577_charger_probe,
	.remove = max14577_charger_remove,
	.id_table = max14577_charger_id,
	};
	module_platform_driver(max14577_charger_driver);

	MODULE_AUTHOR("Krzysztof Kozlowski <k.kozlowski@samsung.com>");
	MODULE_DESCRIPTION("Maxim 14577/77836 charger driver");
	MODULE_LICENSE("GPL");