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// SPDX-License-Identifier: GPL-2.0
//
// max17040_battery.c
// fuel-gauge systems for lithium-ion (Li+) batteries
//
// Copyright (C) 2009 Samsung Electronics
// Minkyu Kang <mk7.kang@samsung.com>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/power_supply.h>
#include <linux/max17040_battery.h>
#include <linux/slab.h>
#define MAX17040_VCELL 0x02
#define MAX17040_SOC 0x04
#define MAX17040_MODE 0x06
#define MAX17040_VER 0x08
#define MAX17040_RCOMP 0x0C
#define MAX17040_CMD 0xFE
#define MAX17040_DELAY 1000
#define MAX17040_BATTERY_FULL 95
#define MAX17040_ATHD_MASK 0xFFC0
#define MAX17040_ATHD_DEFAULT_POWER_UP 4
struct max17040_chip {
struct i2c_client *client;
struct delayed_work work;
struct power_supply *battery;
struct max17040_platform_data *pdata;
/* State Of Connect */
int online;
/* battery voltage */
int vcell;
/* battery capacity */
int soc;
/* State Of Charge */
int status;
/* Low alert threshold from 32% to 1% of the State of Charge */
u32 low_soc_alert;
};
static int max17040_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct max17040_chip *chip = power_supply_get_drvdata(psy);
switch (psp) {
case POWER_SUPPLY_PROP_STATUS:
val->intval = chip->status;
break;
case POWER_SUPPLY_PROP_ONLINE:
val->intval = chip->online;
break;
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
val->intval = chip->vcell;
break;
case POWER_SUPPLY_PROP_CAPACITY:
val->intval = chip->soc;
break;
default:
return -EINVAL;
}
return 0;
}
static int max17040_write_reg(struct i2c_client *client, int reg, u16 value)
{
int ret;
ret = i2c_smbus_write_word_swapped(client, reg, value);
if (ret < 0)
dev_err(&client->dev, "%s: err %d\n", __func__, ret);
return ret;
}
static int max17040_read_reg(struct i2c_client *client, int reg)
{
int ret;
ret = i2c_smbus_read_word_swapped(client, reg);
if (ret < 0)
dev_err(&client->dev, "%s: err %d\n", __func__, ret);
return ret;
}
static void max17040_reset(struct i2c_client *client)
{
max17040_write_reg(client, MAX17040_CMD, 0x0054);
}
static int max17040_set_low_soc_alert(struct i2c_client *client, u32 level)
{
int ret;
u16 data;
level = 32 - level;
data = max17040_read_reg(client, MAX17040_RCOMP);
/* clear the alrt bit and set LSb 5 bits */
data &= MAX17040_ATHD_MASK;
data |= level;
ret = max17040_write_reg(client, MAX17040_RCOMP, data);
return ret;
}
static void max17040_get_vcell(struct i2c_client *client)
{
struct max17040_chip *chip = i2c_get_clientdata(client);
u16 vcell;
vcell = max17040_read_reg(client, MAX17040_VCELL);
chip->vcell = vcell;
}
static void max17040_get_soc(struct i2c_client *client)
{
struct max17040_chip *chip = i2c_get_clientdata(client);
u16 soc;
soc = max17040_read_reg(client, MAX17040_SOC);
chip->soc = (soc >> 8);
}
static void max17040_get_version(struct i2c_client *client)
{
u16 version;
version = max17040_read_reg(client, MAX17040_VER);
dev_info(&client->dev, "MAX17040 Fuel-Gauge Ver 0x%x\n", version);
}
static void max17040_get_online(struct i2c_client *client)
{
struct max17040_chip *chip = i2c_get_clientdata(client);
if (chip->pdata && chip->pdata->battery_online)
chip->online = chip->pdata->battery_online();
else
chip->online = 1;
}
static void max17040_get_status(struct i2c_client *client)
{
struct max17040_chip *chip = i2c_get_clientdata(client);
if (!chip->pdata || !chip->pdata->charger_online
|| !chip->pdata->charger_enable) {
chip->status = POWER_SUPPLY_STATUS_UNKNOWN;
return;
}
if (chip->pdata->charger_online()) {
if (chip->pdata->charger_enable())
chip->status = POWER_SUPPLY_STATUS_CHARGING;
else
chip->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
} else {
chip->status = POWER_SUPPLY_STATUS_DISCHARGING;
}
if (chip->soc > MAX17040_BATTERY_FULL)
chip->status = POWER_SUPPLY_STATUS_FULL;
}
static int max17040_get_of_data(struct max17040_chip *chip)
{
struct device *dev = &chip->client->dev;
chip->low_soc_alert = MAX17040_ATHD_DEFAULT_POWER_UP;
device_property_read_u32(dev,
"maxim,alert-low-soc-level",
&chip->low_soc_alert);
if (chip->low_soc_alert <= 0 || chip->low_soc_alert >= 33)
return -EINVAL;
return 0;
}
static void max17040_check_changes(struct i2c_client *client)
{
max17040_get_vcell(client);
max17040_get_soc(client);
max17040_get_online(client);
max17040_get_status(client);
}
static void max17040_work(struct work_struct *work)
{
struct max17040_chip *chip;
int last_soc, last_status;
chip = container_of(work, struct max17040_chip, work.work);
/* store SOC and status to check changes */
last_soc = chip->soc;
last_status = chip->status;
max17040_check_changes(chip->client);
/* check changes and send uevent */
if (last_soc != chip->soc || last_status != chip->status)
power_supply_changed(chip->battery);
queue_delayed_work(system_power_efficient_wq, &chip->work,
MAX17040_DELAY);
}
static irqreturn_t max17040_thread_handler(int id, void *dev)
{
struct max17040_chip *chip = dev;
struct i2c_client *client = chip->client;
dev_warn(&client->dev, "IRQ: Alert battery low level");
/* read registers */
max17040_check_changes(chip->client);
/* send uevent */
power_supply_changed(chip->battery);
/* reset alert bit */
max17040_set_low_soc_alert(client, chip->low_soc_alert);
return IRQ_HANDLED;
}
static int max17040_enable_alert_irq(struct max17040_chip *chip)
{
struct i2c_client *client = chip->client;
unsigned int flags;
int ret;
flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT;
ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
max17040_thread_handler, flags,
chip->battery->desc->name, chip);
return ret;
}
static enum power_supply_property max17040_battery_props[] = {
POWER_SUPPLY_PROP_STATUS,
POWER_SUPPLY_PROP_ONLINE,
POWER_SUPPLY_PROP_VOLTAGE_NOW,
POWER_SUPPLY_PROP_CAPACITY,
};
static const struct power_supply_desc max17040_battery_desc = {
.name = "battery",
.type = POWER_SUPPLY_TYPE_BATTERY,
.get_property = max17040_get_property,
.properties = max17040_battery_props,
.num_properties = ARRAY_SIZE(max17040_battery_props),
};
static int max17040_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct i2c_adapter *adapter = client->adapter;
struct power_supply_config psy_cfg = {};
struct max17040_chip *chip;
int ret;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
return -EIO;
chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
if (!chip)
return -ENOMEM;
chip->client = client;
chip->pdata = client->dev.platform_data;
ret = max17040_get_of_data(chip);
if (ret) {
dev_err(&client->dev,
"failed: low SOC alert OF data out of bounds\n");
return ret;
}
i2c_set_clientdata(client, chip);
psy_cfg.drv_data = chip;
chip->battery = power_supply_register(&client->dev,
&max17040_battery_desc, &psy_cfg);
if (IS_ERR(chip->battery)) {
dev_err(&client->dev, "failed: power supply register\n");
return PTR_ERR(chip->battery);
}
max17040_reset(client);
max17040_get_version(client);
/* check interrupt */
if (client->irq && of_device_is_compatible(client->dev.of_node,
"maxim,max77836-battery")) {
ret = max17040_set_low_soc_alert(client, chip->low_soc_alert);
if (ret) {
dev_err(&client->dev,
"Failed to set low SOC alert: err %d\n", ret);
return ret;
}
ret = max17040_enable_alert_irq(chip);
if (ret) {
client->irq = 0;
dev_warn(&client->dev,
"Failed to get IRQ err %d\n", ret);
}
}
INIT_DEFERRABLE_WORK(&chip->work, max17040_work);
queue_delayed_work(system_power_efficient_wq, &chip->work,
MAX17040_DELAY);
return 0;
}
static int max17040_remove(struct i2c_client *client)
{
struct max17040_chip *chip = i2c_get_clientdata(client);
power_supply_unregister(chip->battery);
cancel_delayed_work(&chip->work);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int max17040_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct max17040_chip *chip = i2c_get_clientdata(client);
cancel_delayed_work(&chip->work);
if (client->irq && device_may_wakeup(dev))
enable_irq_wake(client->irq);
return 0;
}
static int max17040_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct max17040_chip *chip = i2c_get_clientdata(client);
queue_delayed_work(system_power_efficient_wq, &chip->work,
MAX17040_DELAY);
if (client->irq && device_may_wakeup(dev))
disable_irq_wake(client->irq);
return 0;
}
static SIMPLE_DEV_PM_OPS(max17040_pm_ops, max17040_suspend, max17040_resume);
#define MAX17040_PM_OPS (&max17040_pm_ops)
#else
#define MAX17040_PM_OPS NULL
#endif /* CONFIG_PM_SLEEP */
static const struct i2c_device_id max17040_id[] = {
{ "max17040" },
{ "max77836-battery" },
{ }
};
MODULE_DEVICE_TABLE(i2c, max17040_id);
static const struct of_device_id max17040_of_match[] = {
{ .compatible = "maxim,max17040" },
{ .compatible = "maxim,max77836-battery" },
{ },
};
MODULE_DEVICE_TABLE(of, max17040_of_match);
static struct i2c_driver max17040_i2c_driver = {
.driver = {
.name = "max17040",
.of_match_table = max17040_of_match,
.pm = MAX17040_PM_OPS,
},
.probe = max17040_probe,
.remove = max17040_remove,
.id_table = max17040_id,
};
module_i2c_driver(max17040_i2c_driver);
MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
MODULE_DESCRIPTION("MAX17040 Fuel Gauge");
MODULE_LICENSE("GPL");