android_kernel_xiaomi_sm8350/drivers/power/supply/max17040_battery.c
Jonathan Bakker e3d47125a4 power: supply: max17040: Correct voltage reading
[ Upstream commit 0383024f811aa469df258039807810fc3793a105 ]

According to the datasheet available at (1), the bottom four
bits are always zero and the actual voltage is 1.25x this value
in mV.  Since the kernel API specifies that voltages should be in
uV, it should report 1250x the shifted value.

1) https://datasheets.maximintegrated.com/en/ds/MAX17040-MAX17041.pdf

Signed-off-by: Jonathan Bakker <xc-racer2@live.ca>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:59 +02:00

298 lines
6.8 KiB
C

// 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/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
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;
};
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 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 >> 4) * 1250;
}
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 void max17040_work(struct work_struct *work)
{
struct max17040_chip *chip;
chip = container_of(work, struct max17040_chip, work.work);
max17040_get_vcell(chip->client);
max17040_get_soc(chip->client);
max17040_get_online(chip->client);
max17040_get_status(chip->client);
queue_delayed_work(system_power_efficient_wq, &chip->work,
MAX17040_DELAY);
}
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;
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;
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);
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);
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);
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");