/*
 * Power supply driver for the Active-semi ACT8945A PMIC
 *
 * Copyright (C) 2015 Atmel Corporation
 *
 * Author: Wenyou Yang <wenyou.yang@atmel.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/regmap.h>

static const char *act8945a_charger_model = "ACT8945A";
static const char *act8945a_charger_manufacturer = "Active-semi";

/**
 * ACT8945A Charger Register Map
 */

/* 0x70: Reserved */
#define ACT8945A_APCH_CFG		0x71
#define ACT8945A_APCH_STATUS		0x78
#define ACT8945A_APCH_CTRL		0x79
#define ACT8945A_APCH_STATE		0x7A

/* ACT8945A_APCH_CFG */
#define APCH_CFG_OVPSET			(0x3 << 0)
#define APCH_CFG_OVPSET_6V6		(0x0 << 0)
#define APCH_CFG_OVPSET_7V		(0x1 << 0)
#define APCH_CFG_OVPSET_7V5		(0x2 << 0)
#define APCH_CFG_OVPSET_8V		(0x3 << 0)
#define APCH_CFG_PRETIMO		(0x3 << 2)
#define APCH_CFG_PRETIMO_40_MIN		(0x0 << 2)
#define APCH_CFG_PRETIMO_60_MIN		(0x1 << 2)
#define APCH_CFG_PRETIMO_80_MIN		(0x2 << 2)
#define APCH_CFG_PRETIMO_DISABLED	(0x3 << 2)
#define APCH_CFG_TOTTIMO		(0x3 << 4)
#define APCH_CFG_TOTTIMO_3_HOUR		(0x0 << 4)
#define APCH_CFG_TOTTIMO_4_HOUR		(0x1 << 4)
#define APCH_CFG_TOTTIMO_5_HOUR		(0x2 << 4)
#define APCH_CFG_TOTTIMO_DISABLED	(0x3 << 4)
#define APCH_CFG_SUSCHG			(0x1 << 7)

#define APCH_STATUS_CHGDAT		BIT(0)
#define APCH_STATUS_INDAT		BIT(1)
#define APCH_STATUS_TEMPDAT		BIT(2)
#define APCH_STATUS_TIMRDAT		BIT(3)
#define APCH_STATUS_CHGSTAT		BIT(4)
#define APCH_STATUS_INSTAT		BIT(5)
#define APCH_STATUS_TEMPSTAT		BIT(6)
#define APCH_STATUS_TIMRSTAT		BIT(7)

#define APCH_CTRL_CHGEOCOUT		BIT(0)
#define APCH_CTRL_INDIS			BIT(1)
#define APCH_CTRL_TEMPOUT		BIT(2)
#define APCH_CTRL_TIMRPRE		BIT(3)
#define APCH_CTRL_CHGEOCIN		BIT(4)
#define APCH_CTRL_INCON			BIT(5)
#define APCH_CTRL_TEMPIN		BIT(6)
#define APCH_CTRL_TIMRTOT		BIT(7)

#define APCH_STATE_ACINSTAT		(0x1 << 1)
#define APCH_STATE_CSTATE		(0x3 << 4)
#define APCH_STATE_CSTATE_SHIFT		4
#define APCH_STATE_CSTATE_DISABLED	0x00
#define APCH_STATE_CSTATE_EOC		0x01
#define APCH_STATE_CSTATE_FAST		0x02
#define APCH_STATE_CSTATE_PRE		0x03

struct act8945a_charger {
	struct regmap *regmap;
	bool battery_temperature;
};

static int act8945a_get_charger_state(struct regmap *regmap, int *val)
{
	int ret;
	unsigned int status, state;

	ret = regmap_read(regmap, ACT8945A_APCH_STATUS, &status);
	if (ret < 0)
		return ret;

	ret = regmap_read(regmap, ACT8945A_APCH_STATE, &state);
	if (ret < 0)
		return ret;

	state &= APCH_STATE_CSTATE;
	state >>= APCH_STATE_CSTATE_SHIFT;

	if (state == APCH_STATE_CSTATE_EOC) {
		if (status & APCH_STATUS_CHGDAT)
			*val = POWER_SUPPLY_STATUS_FULL;
		else
			*val = POWER_SUPPLY_STATUS_NOT_CHARGING;
	} else if ((state == APCH_STATE_CSTATE_FAST) ||
		   (state == APCH_STATE_CSTATE_PRE)) {
		*val = POWER_SUPPLY_STATUS_CHARGING;
	} else {
		*val = POWER_SUPPLY_STATUS_NOT_CHARGING;
	}

	return 0;
}

static int act8945a_get_charge_type(struct regmap *regmap, int *val)
{
	int ret;
	unsigned int state;

	ret = regmap_read(regmap, ACT8945A_APCH_STATE, &state);
	if (ret < 0)
		return ret;

	state &= APCH_STATE_CSTATE;
	state >>= APCH_STATE_CSTATE_SHIFT;

	switch (state) {
	case APCH_STATE_CSTATE_PRE:
		*val = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
		break;
	case APCH_STATE_CSTATE_FAST:
		*val = POWER_SUPPLY_CHARGE_TYPE_FAST;
		break;
	case APCH_STATE_CSTATE_EOC:
	case APCH_STATE_CSTATE_DISABLED:
	default:
		*val = POWER_SUPPLY_CHARGE_TYPE_NONE;
	}

	return 0;
}

static int act8945a_get_battery_health(struct act8945a_charger *charger,
				       struct regmap *regmap, int *val)
{
	int ret;
	unsigned int status;

	ret = regmap_read(regmap, ACT8945A_APCH_STATUS, &status);
	if (ret < 0)
		return ret;

	if (charger->battery_temperature && !(status & APCH_STATUS_TEMPDAT))
		*val = POWER_SUPPLY_HEALTH_OVERHEAT;
	else if (!(status & APCH_STATUS_INDAT))
		*val = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
	else if (status & APCH_STATUS_TIMRDAT)
		*val = POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
	else
		*val = POWER_SUPPLY_HEALTH_GOOD;

	return 0;
}

static enum power_supply_property act8945a_charger_props[] = {
	POWER_SUPPLY_PROP_STATUS,
	POWER_SUPPLY_PROP_CHARGE_TYPE,
	POWER_SUPPLY_PROP_TECHNOLOGY,
	POWER_SUPPLY_PROP_HEALTH,
	POWER_SUPPLY_PROP_MODEL_NAME,
	POWER_SUPPLY_PROP_MANUFACTURER
};

static int act8945a_charger_get_property(struct power_supply *psy,
					 enum power_supply_property prop,
					 union power_supply_propval *val)
{
	struct act8945a_charger *charger = power_supply_get_drvdata(psy);
	struct regmap *regmap = charger->regmap;
	int ret = 0;

	switch (prop) {
	case POWER_SUPPLY_PROP_STATUS:
		ret = act8945a_get_charger_state(regmap, &val->intval);
		break;
	case POWER_SUPPLY_PROP_CHARGE_TYPE:
		ret = act8945a_get_charge_type(regmap, &val->intval);
		break;
	case POWER_SUPPLY_PROP_TECHNOLOGY:
		val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
		break;
	case POWER_SUPPLY_PROP_HEALTH:
		ret = act8945a_get_battery_health(charger,
						  regmap, &val->intval);
		break;
	case POWER_SUPPLY_PROP_MODEL_NAME:
		val->strval = act8945a_charger_model;
		break;
	case POWER_SUPPLY_PROP_MANUFACTURER:
		val->strval = act8945a_charger_manufacturer;
		break;
	default:
		return -EINVAL;
	}

	return ret;
}

static const struct power_supply_desc act8945a_charger_desc = {
	.name		= "act8945a-charger",
	.type		= POWER_SUPPLY_TYPE_BATTERY,
	.get_property	= act8945a_charger_get_property,
	.properties	= act8945a_charger_props,
	.num_properties	= ARRAY_SIZE(act8945a_charger_props),
};

#define DEFAULT_TOTAL_TIME_OUT		3
#define DEFAULT_PRE_TIME_OUT		40
#define DEFAULT_INPUT_OVP_THRESHOLD	6600

static int act8945a_charger_config(struct device *dev,
				   struct act8945a_charger *charger)
{
	struct device_node *np = dev->of_node;
	enum of_gpio_flags flags;
	struct regmap *regmap = charger->regmap;

	u32 total_time_out;
	u32 pre_time_out;
	u32 input_voltage_threshold;
	int chglev_pin;

	unsigned int value = 0;

	if (!np) {
		dev_err(dev, "no charger of node\n");
		return -EINVAL;
	}

	charger->battery_temperature = of_property_read_bool(np,
				"active-semi,check-battery-temperature");

	chglev_pin = of_get_named_gpio_flags(np,
				"active-semi,chglev-gpios", 0, &flags);

	if (gpio_is_valid(chglev_pin)) {
		gpio_set_value(chglev_pin,
			       ((flags == OF_GPIO_ACTIVE_LOW) ? 0 : 1));
	}

	if (of_property_read_u32(np,
				 "active-semi,input-voltage-threshold-microvolt",
				 &input_voltage_threshold))
		input_voltage_threshold = DEFAULT_INPUT_OVP_THRESHOLD;

	if (of_property_read_u32(np,
				 "active-semi,precondition-timeout",
				 &pre_time_out))
		pre_time_out = DEFAULT_PRE_TIME_OUT;

	if (of_property_read_u32(np, "active-semi,total-timeout",
				 &total_time_out))
		total_time_out = DEFAULT_TOTAL_TIME_OUT;

	switch (input_voltage_threshold) {
	case 8000:
		value |= APCH_CFG_OVPSET_8V;
		break;
	case 7500:
		value |= APCH_CFG_OVPSET_7V5;
		break;
	case 7000:
		value |= APCH_CFG_OVPSET_7V;
		break;
	case 6600:
	default:
		value |= APCH_CFG_OVPSET_6V6;
		break;
	}

	switch (pre_time_out) {
	case 60:
		value |= APCH_CFG_PRETIMO_60_MIN;
		break;
	case 80:
		value |= APCH_CFG_PRETIMO_80_MIN;
		break;
	case 0:
		value |= APCH_CFG_PRETIMO_DISABLED;
		break;
	case 40:
	default:
		value |= APCH_CFG_PRETIMO_40_MIN;
		break;
	}

	switch (total_time_out) {
	case 4:
		value |= APCH_CFG_TOTTIMO_4_HOUR;
		break;
	case 5:
		value |= APCH_CFG_TOTTIMO_5_HOUR;
		break;
	case 0:
		value |= APCH_CFG_TOTTIMO_DISABLED;
		break;
	case 3:
	default:
		value |= APCH_CFG_TOTTIMO_3_HOUR;
		break;
	}

	return regmap_write(regmap, ACT8945A_APCH_CFG, value);
}

static int act8945a_charger_probe(struct platform_device *pdev)
{
	struct act8945a_charger *charger;
	struct power_supply *psy;
	struct power_supply_config psy_cfg = {};
	int ret;

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

	charger->regmap = dev_get_regmap(pdev->dev.parent, NULL);
	if (!charger->regmap) {
		dev_err(&pdev->dev, "Parent did not provide regmap\n");
		return -EINVAL;
	}

	ret = act8945a_charger_config(pdev->dev.parent, charger);
	if (ret)
		return ret;

	psy_cfg.of_node	= pdev->dev.parent->of_node;
	psy_cfg.drv_data = charger;

	psy = devm_power_supply_register(&pdev->dev,
					 &act8945a_charger_desc,
					 &psy_cfg);
	if (IS_ERR(psy)) {
		dev_err(&pdev->dev, "failed to register power supply\n");
		return PTR_ERR(psy);
	}

	return 0;
}

static struct platform_driver act8945a_charger_driver = {
	.driver	= {
		.name = "act8945a-charger",
	},
	.probe	= act8945a_charger_probe,
};
module_platform_driver(act8945a_charger_driver);

MODULE_DESCRIPTION("Active-semi ACT8945A ActivePath charger driver");
MODULE_AUTHOR("Wenyou Yang <wenyou.yang@atmel.com>");
MODULE_LICENSE("GPL");