/*
* Battery charger driver for the Maxim 14577
*
* Copyright (C) 2013 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>
struct max14577_charger {
struct device *dev;
struct max14577 *max14577;
struct power_supply charger;
unsigned int charging_state;
unsigned int battery_state;
};
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, ®_data);
if ((reg_data & CHGCTRL2_MBCHOSTEN_MASK) == 0)
goto state_set;
max14577_read_reg(rmap, MAX14577_CHG_REG_STATUS3, ®_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;
max14577_read_reg(rmap, MAX14577_MUIC_REG_STATUS2, ®_data);
reg_data = ((reg_data & STATUS2_CHGTYP_MASK) >> STATUS2_CHGTYP_SHIFT);
switch (reg_data) {
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:
return 1;
case MAX14577_CHARGER_TYPE_NONE:
case MAX14577_CHARGER_TYPE_DOWNSTREAM_PORT:
case MAX14577_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;
max14577_read_reg(rmap, MAX14577_MUIC_REG_STATUS2, ®_data);
reg_data = ((reg_data & STATUS2_CHGTYP_MASK) >> STATUS2_CHGTYP_SHIFT);
if (reg_data == MAX14577_CHARGER_TYPE_DEAD_BATTERY) {
state = POWER_SUPPLY_HEALTH_DEAD;
goto state_set;
}
max14577_read_reg(rmap, MAX14577_CHG_REG_STATUS3, ®_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;
}
/*
* 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 void max14577_charger_reg_init(struct max14577_charger *chg)
{
struct regmap *rmap = chg->max14577->regmap;
u8 reg_data;
/*
* 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);
/* Battery Fast-Charge Timer, from SM-V700: 6hrs */
reg_data = 0x3 << CHGCTRL1_TCHW_SHIFT;
max14577_write_reg(rmap, MAX14577_REG_CHGCTRL1, 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);
/* Battery-Charger Constant Voltage (CV) Mode, from SM-V700: 4.35V */
reg_data = 0xf << CHGCTRL3_MBCCVWRC_SHIFT;
max14577_write_reg(rmap, MAX14577_REG_CHGCTRL3, reg_data);
/*
* Fast Battery-Charge Current Low, default 200-950mA
* Fast Battery-Charge Current High, from SM-V700: 450mA
*/
reg_data = 0x1 << CHGCTRL4_MBCICHWRCL_SHIFT;
reg_data |= 0x5 << CHGCTRL4_MBCICHWRCH_SHIFT;
max14577_write_reg(rmap, MAX14577_REG_CHGCTRL4, reg_data);
/* End-of-Charge Current, from SM-V700: 50mA */
reg_data = 0x0 << CHGCTRL5_EOCS_SHIFT;
max14577_write_reg(rmap, MAX14577_REG_CHGCTRL5, reg_data);
/* Auto Charging Stop, default off */
reg_data = 0x0 << CHGCTRL6_AUTOSTOP_SHIFT;
max14577_write_reg(rmap, MAX14577_REG_CHGCTRL6, reg_data);
/* Overvoltage-Protection Threshold, from SM-V700: 6.5V */
reg_data = 0x2 << CHGCTRL7_OTPCGHCVS_SHIFT;
max14577_write_reg(rmap, MAX14577_REG_CHGCTRL7, reg_data);
}
/* 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 *model_name = "MAX14577";
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:
val->strval = model_name;
break;
case POWER_SUPPLY_PROP_MANUFACTURER:
val->strval = manufacturer;
break;
default:
return -EINVAL;
}
return ret;
}
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;
max14577_charger_reg_init(chg);
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 = power_supply_register(&pdev->dev, &chg->charger);
if (ret) {
dev_err(&pdev->dev, "failed: power supply register\n");
return ret;
}
return 0;
}
static int max14577_charger_remove(struct platform_device *pdev)
{
struct max14577_charger *chg = platform_get_drvdata(pdev);
power_supply_unregister(&chg->charger);
return 0;
}
static struct platform_driver max14577_charger_driver = {
.driver = {
.owner = THIS_MODULE,
.name = "max14577-charger",
},
.probe = max14577_charger_probe,
.remove = max14577_charger_remove,
};
module_platform_driver(max14577_charger_driver);
MODULE_AUTHOR("Krzysztof Kozlowski <k.kozlowski@samsung.com>");
MODULE_DESCRIPTION("MAXIM 14577 charger driver");
MODULE_LICENSE("GPL");
