// SPDX-License-Identifier: GPL-2.0
//
// max17040_battery.c
// fuel-gauge systems for lithium-ion (Li+) batteries
//
// Copyright (C) 2009 Samsung Electronics
// Minkyu Kang <[email protected]>
#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/of.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/iio/consumer.h>
#define MAX17040_VCELL 0x02
#define MAX17040_SOC 0x04
#define MAX17040_MODE 0x06
#define MAX17040_VER 0x08
#define MAX17040_CONFIG 0x0C
#define MAX17040_STATUS 0x1A
#define MAX17040_CMD 0xFE
#define MAX17040_DELAY 1000
#define MAX17040_BATTERY_FULL 95
#define MAX17040_RCOMP_DEFAULT 0x9700
#define MAX17040_ATHD_MASK 0x3f
#define MAX17040_ALSC_MASK 0x40
#define MAX17040_ATHD_DEFAULT_POWER_UP 4
#define MAX17040_STATUS_HD_MASK 0x1000
#define MAX17040_STATUS_SC_MASK 0x2000
#define MAX17040_CFG_RCOMP_MASK 0xff00
enum chip_id {
ID_MAX17040,
ID_MAX17041,
ID_MAX17043,
ID_MAX17044,
ID_MAX17048,
ID_MAX17049,
ID_MAX17058,
ID_MAX17059,
};
/* values that differ by chip_id */
struct chip_data {
u16 reset_val;
u16 vcell_shift;
u16 vcell_mul;
u16 vcell_div;
u8 has_low_soc_alert;
u8 rcomp_bytes;
u8 has_soc_alert;
};
static struct chip_data max17040_family[] = {
[ID_MAX17040] = {
.reset_val = 0x0054,
.vcell_shift = 4,
.vcell_mul = 1250,
.vcell_div = 1,
.has_low_soc_alert = 0,
.rcomp_bytes = 2,
.has_soc_alert = 0,
},
[ID_MAX17041] = {
.reset_val = 0x0054,
.vcell_shift = 4,
.vcell_mul = 2500,
.vcell_div = 1,
.has_low_soc_alert = 0,
.rcomp_bytes = 2,
.has_soc_alert = 0,
},
[ID_MAX17043] = {
.reset_val = 0x0054,
.vcell_shift = 4,
.vcell_mul = 1250,
.vcell_div = 1,
.has_low_soc_alert = 1,
.rcomp_bytes = 1,
.has_soc_alert = 0,
},
[ID_MAX17044] = {
.reset_val = 0x0054,
.vcell_shift = 4,
.vcell_mul = 2500,
.vcell_div = 1,
.has_low_soc_alert = 1,
.rcomp_bytes = 1,
.has_soc_alert = 0,
},
[ID_MAX17048] = {
.reset_val = 0x5400,
.vcell_shift = 0,
.vcell_mul = 625,
.vcell_div = 8,
.has_low_soc_alert = 1,
.rcomp_bytes = 1,
.has_soc_alert = 1,
},
[ID_MAX17049] = {
.reset_val = 0x5400,
.vcell_shift = 0,
.vcell_mul = 625,
.vcell_div = 4,
.has_low_soc_alert = 1,
.rcomp_bytes = 1,
.has_soc_alert = 1,
},
[ID_MAX17058] = {
.reset_val = 0x5400,
.vcell_shift = 0,
.vcell_mul = 625,
.vcell_div = 8,
.has_low_soc_alert = 1,
.rcomp_bytes = 1,
.has_soc_alert = 0,
},
[ID_MAX17059] = {
.reset_val = 0x5400,
.vcell_shift = 0,
.vcell_mul = 625,
.vcell_div = 4,
.has_low_soc_alert = 1,
.rcomp_bytes = 1,
.has_soc_alert = 0,
},
};
struct max17040_chip {
struct i2c_client *client;
struct regmap *regmap;
struct delayed_work work;
struct power_supply *battery;
struct chip_data data;
struct iio_channel *channel_temp;
/* battery capacity */
int soc;
/* Low alert threshold from 32% to 1% of the State of Charge */
u32 low_soc_alert;
/* some devices return twice the capacity */
bool quirk_double_soc;
/* higher 8 bits for 17043+, 16 bits for 17040,41 */
u16 rcomp;
};
static int max17040_reset(struct max17040_chip *chip)
{
return regmap_write(chip->regmap, MAX17040_CMD, chip->data.reset_val);
}
static int max17040_set_low_soc_alert(struct max17040_chip *chip, u32 level)
{
level = 32 - level * (chip->quirk_double_soc ? 2 : 1);
return regmap_update_bits(chip->regmap, MAX17040_CONFIG,
MAX17040_ATHD_MASK, level);
}
static int max17040_set_soc_alert(struct max17040_chip *chip, bool enable)
{
return regmap_update_bits(chip->regmap, MAX17040_CONFIG,
MAX17040_ALSC_MASK, enable ? MAX17040_ALSC_MASK : 0);
}
static int max17040_set_rcomp(struct max17040_chip *chip, u16 rcomp)
{
u16 mask = chip->data.rcomp_bytes == 2 ?
0xffff : MAX17040_CFG_RCOMP_MASK;
return regmap_update_bits(chip->regmap, MAX17040_CONFIG, mask, rcomp);
}
static int max17040_raw_vcell_to_uvolts(struct max17040_chip *chip, u16 vcell)
{
struct chip_data *d = &chip->data;
return (vcell >> d->vcell_shift) * d->vcell_mul / d->vcell_div;
}
static int max17040_get_vcell(struct max17040_chip *chip)
{
u32 vcell;
regmap_read(chip->regmap, MAX17040_VCELL, &vcell);
return max17040_raw_vcell_to_uvolts(chip, vcell);
}
static int max17040_get_soc(struct max17040_chip *chip)
{
u32 soc;
regmap_read(chip->regmap, MAX17040_SOC, &soc);
return soc >> (chip->quirk_double_soc ? 9 : 8);
}
static int max17040_get_version(struct max17040_chip *chip)
{
int ret;
u32 version;
ret = regmap_read(chip->regmap, MAX17040_VER, &version);
return ret ? ret : version;
}
static int max17040_get_online(struct max17040_chip *chip)
{
return 1;
}
static int max17040_get_of_data(struct max17040_chip *chip)
{
struct device *dev = &chip->client->dev;
struct chip_data *data = &max17040_family[
(uintptr_t) of_device_get_match_data(dev)];
int rcomp_len;
u8 rcomp[2];
chip->quirk_double_soc = device_property_read_bool(dev,
"maxim,double-soc");
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 > (chip->quirk_double_soc ? 16 : 32)) {
dev_err(dev, "maxim,alert-low-soc-level out of bounds\n");
return -EINVAL;
}
rcomp_len = device_property_count_u8(dev, "maxim,rcomp");
chip->rcomp = MAX17040_RCOMP_DEFAULT;
if (rcomp_len == data->rcomp_bytes) {
if (!device_property_read_u8_array(dev, "maxim,rcomp",
rcomp, rcomp_len))
chip->rcomp = rcomp_len == 2 ? rcomp[0] << 8 | rcomp[1] :
rcomp[0] << 8;
} else if (rcomp_len > 0) {
dev_err(dev, "maxim,rcomp has incorrect length\n");
return -EINVAL;
}
return 0;
}
static void max17040_check_changes(struct max17040_chip *chip)
{
chip->soc = max17040_get_soc(chip);
}
static void max17040_queue_work(struct max17040_chip *chip)
{
queue_delayed_work(system_power_efficient_wq, &chip->work,
MAX17040_DELAY);
}
static void max17040_stop_work(void *data)
{
struct max17040_chip *chip = data;
cancel_delayed_work_sync(&chip->work);
}
static void max17040_work(struct work_struct *work)
{
struct max17040_chip *chip;
int last_soc;
chip = container_of(work, struct max17040_chip, work.work);
/* store SOC to check changes */
last_soc = chip->soc;
max17040_check_changes(chip);
/* check changes and send uevent */
if (last_soc != chip->soc)
power_supply_changed(chip->battery);
max17040_queue_work(chip);
}
/* Returns true if alert cause was SOC change, not low SOC */
static bool max17040_handle_soc_alert(struct max17040_chip *chip)
{
bool ret = true;
u32 data;
regmap_read(chip->regmap, MAX17040_STATUS, &data);
if (data & MAX17040_STATUS_HD_MASK) {
// this alert was caused by low soc
ret = false;
}
if (data & MAX17040_STATUS_SC_MASK) {
// soc change bit -- deassert to mark as handled
regmap_write(chip->regmap, MAX17040_STATUS,
data & ~MAX17040_STATUS_SC_MASK);
}
return ret;
}
static irqreturn_t max17040_thread_handler(int id, void *dev)
{
struct max17040_chip *chip = dev;
if (!(chip->data.has_soc_alert && max17040_handle_soc_alert(chip)))
dev_warn(&chip->client->dev, "IRQ: Alert battery low level\n");
/* read registers */
max17040_check_changes(chip);
/* send uevent */
power_supply_changed(chip->battery);
/* reset alert bit */
max17040_set_low_soc_alert(chip, chip->low_soc_alert);
return IRQ_HANDLED;
}
static int max17040_enable_alert_irq(struct max17040_chip *chip)
{
struct i2c_client *client = chip->client;
int ret;
ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
max17040_thread_handler, IRQF_ONESHOT,
chip->battery->desc->name, chip);
return ret;
}
static int max17040_prop_writeable(struct power_supply *psy,
enum power_supply_property psp)
{
switch (psp) {
case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:
return 1;
default:
return 0;
}
}
static int max17040_set_property(struct power_supply *psy,
enum power_supply_property psp,
const union power_supply_propval *val)
{
struct max17040_chip *chip = power_supply_get_drvdata(psy);
int ret;
switch (psp) {
case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:
/* alert threshold can be programmed from 1% up to 16/32% */
if ((val->intval < 1) ||
(val->intval > (chip->quirk_double_soc ? 16 : 32))) {
ret = -EINVAL;
break;
}
ret = max17040_set_low_soc_alert(chip, val->intval);
chip->low_soc_alert = val->intval;
break;
default:
ret = -EINVAL;
}
return ret;
}
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_ONLINE:
case POWER_SUPPLY_PROP_PRESENT:
val->intval = max17040_get_online(chip);
break;
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
val->intval = max17040_get_vcell(chip);
break;
case POWER_SUPPLY_PROP_CAPACITY:
val->intval = max17040_get_soc(chip);
break;
case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:
val->intval = chip->low_soc_alert;
break;
case POWER_SUPPLY_PROP_STATUS:
power_supply_get_property_from_supplier(psy, psp, val);
break;
case POWER_SUPPLY_PROP_TEMP:
if (!chip->channel_temp)
return -ENODATA;
iio_read_channel_processed_scale(chip->channel_temp,
&val->intval, 10);
break;
default:
return -EINVAL;
}
return 0;
}
static const struct regmap_config max17040_regmap = {
.reg_bits = 8,
.reg_stride = 2,
.val_bits = 16,
.val_format_endian = REGMAP_ENDIAN_BIG,
};
static enum power_supply_property max17040_battery_props[] = {
POWER_SUPPLY_PROP_ONLINE,
POWER_SUPPLY_PROP_PRESENT,
POWER_SUPPLY_PROP_VOLTAGE_NOW,
POWER_SUPPLY_PROP_CAPACITY,
POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN,
POWER_SUPPLY_PROP_STATUS,
POWER_SUPPLY_PROP_TEMP,
};
static const struct power_supply_desc max17040_battery_desc = {
.name = "battery",
.type = POWER_SUPPLY_TYPE_BATTERY,
.get_property = max17040_get_property,
.set_property = max17040_set_property,
.property_is_writeable = max17040_prop_writeable,
.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 = i2c_client_get_device_id(client);
struct i2c_adapter *adapter = client->adapter;
struct power_supply_config psy_cfg = {};
struct max17040_chip *chip;
enum chip_id chip_id;
bool enable_irq = false;
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->regmap = devm_regmap_init_i2c(client, &max17040_regmap);
if (IS_ERR(chip->regmap))
return PTR_ERR(chip->regmap);
chip_id = (enum chip_id) id->driver_data;
if (client->dev.of_node) {
ret = max17040_get_of_data(chip);
if (ret)
return ret;
chip_id = (uintptr_t)of_device_get_match_data(&client->dev);
}
chip->data = max17040_family[chip_id];
i2c_set_clientdata(client, chip);
psy_cfg.drv_data = chip;
/* Switch to devm_iio_channel_get_optional when available */
chip->channel_temp = devm_iio_channel_get(&client->dev, "temp");
if (IS_ERR(chip->channel_temp)) {
ret = PTR_ERR(chip->channel_temp);
if (ret != -ENODEV)
return dev_err_probe(&client->dev, PTR_ERR(chip->channel_temp),
"failed to get temp\n");
else
chip->channel_temp = NULL;
}
chip->battery = devm_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);
}
ret = max17040_get_version(chip);
if (ret < 0)
return ret;
dev_dbg(&chip->client->dev, "MAX17040 Fuel-Gauge Ver 0x%x\n", ret);
if (chip_id == ID_MAX17040 || chip_id == ID_MAX17041)
max17040_reset(chip);
max17040_set_rcomp(chip, chip->rcomp);
/* check interrupt */
if (client->irq && chip->data.has_low_soc_alert) {
ret = max17040_set_low_soc_alert(chip, chip->low_soc_alert);
if (ret) {
dev_err(&client->dev,
"Failed to set low SOC alert: err %d\n", ret);
return ret;
}
enable_irq = true;
}
if (client->irq && chip->data.has_soc_alert) {
ret = max17040_set_soc_alert(chip, 1);
if (ret) {
dev_err(&client->dev,
"Failed to set SOC alert: err %d\n", ret);
return ret;
}
enable_irq = true;
} else {
/* soc alerts negate the need for polling */
INIT_DEFERRABLE_WORK(&chip->work, max17040_work);
ret = devm_add_action(&client->dev, max17040_stop_work, chip);
if (ret)
return ret;
max17040_queue_work(chip);
}
if (enable_irq) {
ret = max17040_enable_alert_irq(chip);
if (ret) {
client->irq = 0;
dev_warn(&client->dev,
"Failed to get IRQ err %d\n", ret);
}
}
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);
if (client->irq && chip->data.has_soc_alert)
// disable soc alert to prevent wakeup
max17040_set_soc_alert(chip, 0);
else
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);
if (client->irq && device_may_wakeup(dev))
disable_irq_wake(client->irq);
if (client->irq && chip->data.has_soc_alert)
max17040_set_soc_alert(chip, 1);
else
max17040_queue_work(chip);
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", ID_MAX17040 },
{ "max17041", ID_MAX17041 },
{ "max17043", ID_MAX17043 },
{ "max77836-battery", ID_MAX17043 },
{ "max17044", ID_MAX17044 },
{ "max17048", ID_MAX17048 },
{ "max17049", ID_MAX17049 },
{ "max17058", ID_MAX17058 },
{ "max17059", ID_MAX17059 },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(i2c, max17040_id);
static const struct of_device_id max17040_of_match[] = {
{ .compatible = "maxim,max17040", .data = (void *) ID_MAX17040 },
{ .compatible = "maxim,max17041", .data = (void *) ID_MAX17041 },
{ .compatible = "maxim,max17043", .data = (void *) ID_MAX17043 },
{ .compatible = "maxim,max77836-battery", .data = (void *) ID_MAX17043 },
{ .compatible = "maxim,max17044", .data = (void *) ID_MAX17044 },
{ .compatible = "maxim,max17048", .data = (void *) ID_MAX17048 },
{ .compatible = "maxim,max17049", .data = (void *) ID_MAX17049 },
{ .compatible = "maxim,max17058", .data = (void *) ID_MAX17058 },
{ .compatible = "maxim,max17059", .data = (void *) ID_MAX17059 },
{ /* sentinel */ },
};
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,
.id_table = max17040_id,
};
module_i2c_driver(max17040_i2c_driver);
MODULE_AUTHOR("Minkyu Kang <[email protected]>");
MODULE_DESCRIPTION("MAX17040 Fuel Gauge");
MODULE_LICENSE("GPL");
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